Identificación de enterobacterias multirresistentes a antibióticos en muestras de heces de lactantes residentes en Talara, Piura, Perú / Identification of multidrug-resistant enterobacteriaceae in fecal samples from infants residing in Talara, Piura, Peru Arturo

La colonización fecal en lactantes por bacterias resistentes a los antimicrobianos es un potencial riesgo para futuras terapias antibióticas. Nuestro objetivo fue determinar la frecuencia y características sociodemográficas de lactantes portadores fecales de enterobacterias resistentes a ciprofloxacina (PFRC) y sus genes de resistencia asociados. Analizamos muestras fecales de 41 niños lactantes residentes en el distrito de Talara-Piura, Perú, en 2019. Evaluamos la presencia de 3 genes de resistencia a quinolonas: aac(6')-Ib-cr, qnrB y oqxA y 2 de betalactamasas: bla CTX-M, bla PER-2.El 68% de lactantes fueron PFRC, Escherichia coli (83,3%) fue el más frecuente. El análisis genotípico detectó: oqxA (41,1%), qnrB (26,7%) y aac(6')-Ib-cr (20%) y al gen bla CTX-M en el 93,3% de los aislados con betalactamasas. La elevada frecuencia de PFRC nos alertan sobre el potencial riesgo en la pérdida de utilidad de esta familia antibiótica en el área de estudio.

Fecal colonization by antimicrobial-resistant bacteria in infants is a potential risk for future antibiotic therapy. We aimed to determine the sociodemographic characteristics and frequency of infants who were fecal carriers of ciprofloxacin-resistant enterobacteriaceae (FCCRE) and their associated resistance genes. We analyzed fecal samples from 41 infants from the district of Talara, Piura, Peru in 2019. The presence of 3 quinolone resistance genes was evaluated: aac(6')-Ib-cr, qnrB and oqxA as well as of 2 beta-lactamase genes: bla CTX-M,bla PER-2. We found that 68% of infants were FCCRE, Escherichia coli (83.3%) was the most frequent bacteria. The genotypic analysis detected: oqxA (41.1%), qnrB (26.7%), aac(6')-Ib-cr (20%) and the bla CTX-M gene (93.3%) of the isolates with beta-lactamases. The high frequency of FCCRE alerts us of the potential risk of this antibiotic family becoming less useful over time.

Uso de Quinolonas como Factor de Riesgo para Infección Oportunista Severa por Cándida en Pacientes Adultos Críticamente Enfermos

Resumen Introducción: Candida es uno de los microorganismos mayormente aislado de los hemocultivos positivos, mostrando un aumento de su prevalencia a nivel mundial debido a múltiples factores de riesgo siendo unos de los más importantes el uso de antibioticoterapia de espectro ampliado, como las quinolonas usados en pacientes críticos hospitalizados en salas de cuidado intensivo, de los cuales la literatura es tangencial en su relación con el desarrollo de candidiasis invasiva. Materiales y metodos: se realizó una búsqueda exhaustiva en las bases de datos biomédicas MEDLINE, PubMed, ScienceDirect, Scopus, Embase, utilizando la estrategia de búsqueda: "Candidemia AND Quinolones AND Adult" sin embargo también se usaron otras estrategias para aumentar la sensibilidad como: "Invasive candidiasis AND Quinolones" y "Candidemia OR Invasive candidiasis AND risk factors" incluyendo los idiomas inglés, español, francés y portugués, se tuvieron en cuenta artículos tipo: [Randomized Controlled Trial], [Clinical Trial], [Controlled Clinical Trial] y [Review] Resultados: la literatura biomédica es escasa en cuanto a la descripción de la relación entre el uso de quinolinas como factor de riesgo para desarrollar candidiasis invasiva, sin embargo se encontraron ocho estudios con significancia estadística importante que muestran una relación estrecha entre el fenómeno propuesto. Conclusiónes: Las quinolonas de uso sistémico como Ciprofloxacino, son un factor de riesgo confirmado asociado a infecciones invasivas por hongos tipo Candida.

Abstract Introduction: Candida is one of the microorganisms most frequently isolated from positive blood cultures, showing an increase in its prevalence worldwide due to multiple risk factors, one of the most important being the use of extended-spectrum antibiotic therapy, such as quinolones used in critical patients in intensive care wards, of which the literature is tangential in its relationship with the development of invasive candidiasis, Methods: a search of biomedical databases MEDLINE, PubMed, ScienceDirect, Scopus, Embase, was performed using the search strategy: "Candidemia AND Quinolones AND Adult" other strategies were also used to increase sensitivity such as: "Invasive candidiasis AND Quinolones" and "Candidemia OR Invasive candidiasis AND risk factors" including English, Spanish, French and Portuguese languages, articles type were taken into account: [Randomized Controlled Trial], [Clinical Trial], [Controlled Clinical Trial] and [Review]. Results: The biomedical literature is scarce regarding the description of the relationship between the use of quinolones as a risk factor for developing invasive candidiasis; however, eight studies were found with important statistical significance that show a close relationship between the proposed phenomenon. Conclusion: Systemic quinolones such as Ciprofloxacin are a confirmed risk factor associated with invasive fungal infections such as Candida.

Domestic wastewater treatment plants as sources of macrolide-lincosamide-streptogramin B- and penicillin-resistant Staphylococcus aureus in Brazil / Plantas de tratamiento de aguas residuales domésticas como fuentes de Staphylococcus aureus resistente a macrólidos-lincosamida-estreptogramina B- y penicilina en Brasil / Estações de tratamento de águas residuais domésticas como fontes de Staphylococcus aureus resistente a macrolídeo-lincosamida-estreptograma e B- e penicilina no Brasil

SUMMARY Staphylococcus aureus is one of the main bacteria that affect human health. Its reduced susceptibility to beta-lactam antibiotics has driven the clinical use of macrolides and lincosamides. However, the presence of macrolide-lincosamide-streptogramin B (MLSB)-resistant S. aureus strains is increasingly common. Wastewater treatment plants (WWTPs) are the main anthropogenic source of resistance determinants. However, few studies have assessed the importance of this environment on the dissemination of MLSB-resistant S. aureus strains. Thus, we aimed to evaluate the impact of a domestic WWTP on the resistance to MLSB and penicillin in S. aureus in southeast Brazil. Of the 35 isolates tested, 40.6% were resistant to penicillin. Resistance to erythromycin (8.6%) and quinolones (2.8%) was less common. Despite the low rate of resistance to clindamycin (2.8%), many isolates showed reduced susceptibility to this antibiotic (57.1%). Regarding the resistance phenotypes of staphylococci isolates, inducible MLSB resistance (D-test positive) was found in two isolates. In addition, 27 S. aureus isolates showed the ability to produce penicillinase. In this article, we report for the first time the importance of WWTPs in the dissemination of MSLB resistance among S. aureus from southeast Brazil.

RESUMEN Staphylococcus aureus es una de las principales bacterias que afectan la salud humana. Su susceptibilidad reducida a los antibióticos betalactámicos ha impulsado el uso clínico de macrólidos y lincosamidas. Sin embargo, la presencia de cepas resistentes a macrólido-lincosamida-estreptogramina B (MLSB) de S. aureus es cada vez más común. Las plantas de tratamiento de aguas residuales (PTAR) son la principal fuente antropogénica de determinantes de resistencia. Sin embargo, pocos estudios han evaluado la importancia de este entorno en la diseminación de cepas de S. aureus resistentes a MLSB. Nuestro objetivo fue evaluar el impacto de una PTAR doméstica en MLSB y la resistencia a la penicilina en S. aureus en el sureste de Brasil. De los 35 aislamientos analizados, el 40,6% eran resistentes a la penicilina. La resistencia a la eritromicina (8,6%) y quinolonas (2,8%) fue menos común. A pesar de la baja tasa de resistencia a la clindamicina (2,8%), muchos aislamientos mostraron sensibilidad reducida a este antibiótico (57,1%). Con respecto a los fenotipos de resistencia de los aislamientos de estafilococos, la resistencia inducible a MLSB (prueba D positiva) se encontró en dos aislamientos. Además, 27 aislamientos de S. aureus mostraron la capacidad de producir penicilinasa. En este artículo informamos, por primera vez, la importancia de las PTAR en la difusión de la resistencia a MSLB entre S. aureus del sureste de Brasil.

RESUMO O Staphylococcus aureus é uma das principais bactérias que afetam a saúde humana. Sua reduzida suscetibilidade aos antibióticos beta-lactâmicos tem impulsionado o uso clínico de macrolídeos e lincosamidas. No entanto, a presença de cepas de S. aureus resistentes a macrolídeo-lincosamida-estreptogramina B (MLSB) é cada vez mais comum. As estações de tratamento de esgoto (ETEs) são a principal fonte antropogênica de determinantes de resistência. No entanto, poucos estudos avaliaram a importância desse ambiente na disseminação de cepas de S. aureus resistentes ao MLSB. Assim, nosso objetivo foi avaliar o impacto de uma ETE doméstico na resistência ao MLSB e à penicilina em S. aureus no sudeste do Brasil. Dos 35 isolados testados, 40,6% eram resistentes à penicilina. Resistência à eritromicina (8,6%) e quinolonas (2,8%) foi menos comum. Apesar da baixa taxa de resistência à clindamicina (2,8%), muitos isolados apresentaram sensibilidade reduzida a esse antibiótico (57,1%). Em relação aos fenótipos de resistência dos isolados de estafilococos, a resistência induzível ao MLSB (D-teste positivo) foi encontrada em dois isolados. Além disso, 27 isolados de S. aureus mostraram a capacidade de produzir penicilinase. Neste artigo relatamos pela primeira vez a importância das ETEs na disseminação da resistência do MSLB entre S. aureus do sudeste do Brasil.

Quinolones resistance in Salmonella spp. isolated from broilers and chickens carcasses under federal inspection / Resistência à quinolonas em Salmonella spp. isoladas de frangos vivos e carcaças sob inspeção federal

We analyzed 77 Salmonella spp. strains, from which 20 were isolated from broilers (cloacal swabs) and 57 from chickens from slaughterhouses under federal inspection. The following serotypes were identified: Salmonella Saint Paul (29), Salmonella Heidelberg (27), Salmonella Anatum (9), Salmonella Cerro (5), Salmonella Senftenberg (5), Salmonella enterica (O: 4,5) (1) and Salmonella enterica (O: 9.12) (1). Fifteen strains (19.5%) were resistant to enrofloxacin, six (7.8%) to ciprofloxacin, and 26 (33.8%) to nalidixic acid in the Disk Diffusion Test. The fifteen enrofloxacin resistant strains were selected for the PCR to detect the genes gyrA, gyrB, parC, and parE, and genetic sequencing to identify mutations in these genes. Five strains (33.3%) had point mutations in the gyrA gene, and one (6.7%) presented a point mutation in the parC gene. None of the 15 strains had mutations in the gyrB and parE genes, and none had more than one mutation in the gyrA gene or the other genes. The presence of point mutations in the strains studied corroborates with the phenotypic resistance observed to nalidixic acid. However, it did not explain the resistance to fluoroquinolones found in the 15 strains. Other mechanisms may be related to the fluoroquinolones resistance, highlighting the need for additional mutation screening.(AU)

Foram analisadas neste estudo 77 estirpes de Salmonella spp., 20 isoladas de frangos vivos (suabes de cloaca) e 57 isoladas de carcaças, provenientes de abatedouros frigoríficos sob Inspeção Federal. Foram identificados os seguintes sorotipos: Salmonella Saint Paul (29), Salmonella Heidelberg (27), Salmonella Anatum (9), Salmonella Cerro (5), Salmonella Senftenberg (5), Salmonella enterica (O: 4,5) (1) e Salmonella enterica (O: 9,12) (1). Do total de estirpes estudadas, 15 (19,5%) se mostraram resistentes à enrofloxacina, seis (7,8%) à ciprofloxacina e 26 (33,8%) ao ácido nalidíxico no Teste de Difusão em Disco. Foram selecionadas as 15 estirpes resistentes à enrofloxacina para a realização da PCR para detecção dos genes gyrA, gyrB, parC e parEe para sequenciamento genético do produto da PCR para identificação de mutações nesses genes. Cinco estirpes (33,3%) apresentaram mutações pontuais no gene gyrA e uma (6,7%) apresentou mutação pontual no gene parC. Nenhuma das 15 estirpes apresentou mutações nos genes gyrB e parE e nenhuma apresentou mais de uma mutação no gene gyrA ou nos outros genes. A existência apenas de mutações pontuais em alguns genes das estirpes analisadas está de acordo com a resistência fenotípica observada ao ácido nalidíxico, mas não explica a resistência às fluoroquinolonas encontrada nas 15 estirpes. Outros mecanismos de resistência podem estar relacionados à resistência encontrada às fluoroquinolonas e estudos adicionais são necessários para investigar sua presença.(AU)

Marcadores de resistencia plasmídica a quinolonas qnr en aislamientos clínicos de enterobacterias productoras de betalactamasas CTX-M en Lima, Perú / Markers of plasmid resistance to qnr quinolones in clinical isolates of CTX-M beta-lactamases-producing enterobacteria in Lima, Peru

RESUMEN Con el objetivo de reportar marcadores de resistencia plasmídica a quinolonas qnr en aislamientos clínicos de enterobacterias productoras de betalactamasas CTX-M, se realizó un estudio descriptivo, con aislamientos del cepario del proyecto TO-06/09 del Instituto Nacional de Salud del Niño. Se recuperaron 138 aislamientos. La susceptibilidad antimicrobiana se determinó por el método de disco difusión y la identificación de genes por reacción en cadena de la polimerasa. De los 138 aislados, 67 (48,5%) fueron positivos para proteínas qnr por el método genotípico. De los cuales 38 (56,7%) presentaron determinantes qnrB y 48 (71,6%) determinantes qnrS. Ningún aislado presentó determinantes qnrA. Se detectó determinantes qnr en aislamientos que presentaban betalactamasas CTX-M en una población no expuesta.

ABSTRACT Aimed at reporting markers of plasmid resistance to qnr quinolones in clinical isolates of CTX-M beta-lactamase-producing enterobacteria, a descriptive study was conducted with isolates from the strain repository of TO-06/09 project of the National Children´s Health Institute. 138 isolates were recovered. Antimicrobial susceptibility was determined by the diffusion disk method, and gene identification by polymerase chain reaction. Of the 138 isolates, 67 (48.5%) were genotypically positive for qnr proteins; of these, 38 (56.7%) had qnrB determinants and 48 (71.6%) had qnrS determinants. No isolate presented qnrA determinants. qnr determinants were detected in isolates containing CTX-M beta-lactamases in a non-exposed population.

Ruptura espontánea del semitendinoso secundario al uso de una quinolona / Spontaneous semitendinosus rupture secondary to the use of a quinolone

Resumen La ruptura espontánea de un tendón secundario al uso de una quinolona es un efecto adverso poco común, pero que con el paso de los años se ha venido documentado con mayor frecuencia. A pesar de lo anterior, aún no hay estudios clínicos que permitan aclarar su fisiopatología, qué estrategias pueden disminuir el riesgo de desarrollar una ruptura espontánea o a qué dosis de las diferentes quinolonas se aumenta el riesgo de presentar una ruptura espontánea. Adicionalmente, varías guías de práctica clínica incentivan el uso de las quinolonas como primera línea para el manejo de infecciones respiratorias o de vías urinarias sin hacer consideraciones sobre este efecto adverso. Por lo anterior, presentamos a continuación el caso de un paciente de 31 años que posterior al inicio de ciprofloxacina para el manejo de una diarrea aguda presento una ruptura espontánea del tendón del semitendinoso secundario al uso de la quinolona. (Acta Med Colomb 2019; 44: 115-118).

Abstract The spontaneous rupture of a tendon secondary to the use of a quinolone is an uncommon adverse effect, but over the years has been documented more frequently. Despite this, there are still no clini cal studies to clarify its pathophysiology, nor which strategies can reduce the risk of developing a spontaneous rupture or at what dose of the different quinolones the risk of presenting a spontaneous rupture increases. In addition, several clinical practice guidelines encourage the use of quinolones as the first line for the management of respiratory or urinary tract infections without considering this adverse effect. Therefore, the case of a 31 year old patient who after the start of ciprofloxacin for the management of acute diarrhea had spontaneous semitendinosus tendon rupture secondary to the use of quinolone, is presented. (Acta Med Colomb 2019; 44: 115-118).

Cambios en las prescripciones y el consumo de antimicrobianos, luego de la implementación de recomendaciones de uso: experiencia en un hospital universitario / Changes in prescriptions and antibiotic consumption after the implementation of recommendations for use: experience in a university hospital

Resumen Introduccion: Actualmente cerca de la mitad de las prescripciones de antimicrobianos son inadecuadas, lo que aumenta la resistencia bacteriana. Tanto cefalosporinas como fluoroquinolonas se asocian con este fenomeno: aumento de bacterias productoras de β-lactamasas e infecciones por Clostridioides difficile, por lo que las agencias reguladoras buscan racionalizar su uso. Objetivo: Evaluar el efecto de recomendaciones para el uso adecuado de antimicrobianos en la proporcion de prescripciones inadecuadas de ceftriaxona y fluoroquinolonas. Metodologia: Se desarrollo un estudio de antes y despues, prospectivo e intervencional, que comparo la calidad y la cantidad de uso de ceftriaxona y fluoroquinolonas antes y despues de la implementacion de recomendaciones de uso para tratamientos de enfermedades infecciosas adquiridas en la comunidad. Los parametros medidos fueron: proporcion de prescripciones inadecuadas y DDD. Los datos se analizaron por medio del test de χ2, correccion de Fisher y test de Student. Resultados: Se evaluaron 206 pacientes, observandose una disminucion de 35% en las prescripciones inadecuadas, una reduccion del consumo de ceftriaxona y levofloxacina y un aumento significativo de la utilizacion de ampicilina/sulbactam. Conclusiones: La implementacion de recomendaciones de uso basadas en evidencia cientifica y susceptibilidad local, permitieron disminuir la proporcion de prescripciones inadecuadas y reducir el consumo de ceftriaxona y fluoroquinolonas.

Background: Nowadays about half of antibiotic prescriptions are inadequate, increasing bacterial resistance. Both cephalosporins and fluoroquinolones are associated with this phenomenon: increase of β-lactamase producing bacteria and Clostridioides difficile infections, which is why regulatory agencies seek to rationalize their use. Aim: To evaluate the effect of use recommendations on the proportion of inadequate prescriptions of ceftriaxone and fluoroquinolones. Methods: A prospective and interventional study was developed, comparing the quality and quantity of use of ceftriaxone and fluoroquinolones before and after the implementation of use recommendations for treatments of infectious diseases acquired at the community. The outcomes were: proportion of inadequate prescriptions and defined daily dose (DDD). Data were analyzed using the Chi-square test, Fisher's correction and Student's test. Results: A total of 206 patients were evaluated, a 35% decrease in inadequate prescriptions, a decline in the consumption of ceftriaxone and levofloxacin, and a significant increase in the use of ampicillin/ sulbactam was observed. Conclusions: The implementation of use recommendations based on scientific evidence and local susceptibility allowed to reduce the proportion of inadequate prescriptions and to reduce de consumption of ceftriaxone and fluoroquinolones.

Empleo de los antibióticos de segunda línea para el tratamiento de la cistitis aguda no complicada de la mujer: enfoque actual

RESUMEN Fundamento y objetivo: con este estudio pretendemos identificar los antibióticos considerados de segunda línea para el uso en las infecciones de vías urinarias (IVU), específicamente en las cistitis no complicadas de la mujer. Posteriormente nos proponemos presentar la prevalencia de resistencia a los antibióticos de segunda línea de los gérmenes más frecuentemente encontrados en las IVU en el Laboratorio de Microbiología de la Facultad de Ciencias Médicas, de la Universidad Nacional de Asunción. Material y método: se realizó un trabajo observacional, descriptivo, de corte transverso. Resultados: Escherichia coli presenta un resistencia inferior al 20% en promedio para la cefuroxima, que se mantiene en el lapso observado (2010 - 2017). La resistencia a la ampicilina-sulbactam de dicho germen está variando, de una resistencia elevada en los primeros años de la observación, hasta un acercamiento progresivo en los años precedentes al 30% (en promedio 34%). La resistencia a la ciprofloxacina presenta una tasa superior al 25% en los años de estudiados. En cuanto a la resistencia de Klebsiella pneumoniae a los antibióticos de segunda línea, en los últimos dos años de observación, tanto al grupo de las cefalosporinas, de la ampicilina sulbactam y la ciprofloxacina, se encontró una resistencia mayor al 30%. Conclusiones: los datos muestran una importante resistencia de Escherichia coli y Klebsiella pneumoniae aislados en los urocultivos a los antibióticos identificados como de segunda línea para el tratamiento de las cistitis no complicadas de la mujer, por lo que debe otorgársele un gran peso a los resultados de los urocultivos para la utilización apropiada de estos antibióticos.

ABSTRACT Background and objective: With this study we intended to identify the second-line antibiotics to be used in urinary tract infections (UTI), specifically in uncomplicated cystitis of women. Later, we proposed to present the prevalence of resistance to the second-line antibiotics of the germs most frequently found in the UTI in the Microbiology Laboratory of the Faculty of Medical Sciences of the National University of Asunción. Material and method: An observational, descriptive, cross-sectional study was carried out. Results: Escherichia coli has a resistance to cefuroxine lower than 20% on average, which was maintained in the observed period (2010-2017). The resistance to ampicillin-sulbactam of this germ is varying, from a high resistance in the first years of the observation to a progressive approach to 30% in the preceding years (on average 34%). Resistance to ciprofloxacin presents a rate higher than 25% in the studied years. Regarding the resistance of Klebsiella pneumoniae to the second-line antibiotics, a resistance greater than 30% was found for the group of cephalosporins, ampicillin sulbactam and ciprofloxacin in the last two years of observation. Conclusions: The data show an important resistance of Escherichia coli and Klebsiella pneumoniae isolated in urine cultures to the second-line antibiotics for the treatment of uncomplicated cystitis in women. Therefore, a great weight should be given to the results of the urine cultures for the proper use of these antibiotics.

Genes qnr en Enterobacteriaceae aisladas en un hospital de Venezuela / qnr genes in Enterobacteriaceae isolated from at a hospital in Venezuela

Resumen Introducción: La resistencia de enterobacterias a quinolonas se ha difundido por el mundo, fenómeno presente también en Venezuela. El mecanismo de esta resistencia pudiera estar mediado por genes incluidos en el cromosoma bacteriano o transmitirse en el interior de plásmidos. Objetivo: Evaluar la resistencia a quino-lonas, codificada por genes qnr, presentes en cepas de enterobacterias, aisladas en el Hospital Universitario de Cumaná, Venezuela. Métodos: A las cepas obtenidas se les realizaron pruebas de susceptibilidad antimicrobiana a quinolonas, β-lactámicos y aminoglucósidos. La presencia del gen qnr se determinó por RPC. Las enterobacterias portadoras del gen qnr fueron sometidas al proceso de conjugación bacteriana para comprobar su capacidad de transferencia. A las transconjugantes obtenidas se les realizó pruebas de susceptibilidad antimicrobiana y RPC para comprobar la transferencia de los genes. Resultados: Se encontraron elevados porcentajes de resistencia antimicrobiana a quinolonas y betalactámicos. El 33,6% de las cepas eran portadoras del gen qnrB, y 0,9% del gen qnrA. Se obtuvieron 23 cepas transconjugantes; de éstas, 20 portaban el gen qnrB, no se observó la presencia de qnrA. Discusión: En conclusión, el elevado porcentaje de genes qnr encontrado en las enterobacterias aisladas, y comprobada la presencia de éstos en plásmidos transferibles, complica la aplicación de tratamientos basados en quinolonas y fluoroquinolonas, por lo que es recomendable el uso racional de estos antimicrobianos, y proponer la rotación de la terapia antimicrobiana, a fin de evitar la selección de cepas resistentes.

Background: Enterobacteria resistant to quinolones is increasing worldwide, including Venezuela. The mechanism for this resistance could be due to genes included in the chromosome or in transmissible plasmids. Aim: To evaluate the resistance to quinolones, coded by qnr genes present in enterobacteria species, isolated in the University Hospital of Cumana, Venezuela. Methods: Antimicrobial susceptibility tests to quinolones, beta-lactams and aminoglycosides were carried out to all the isolates. The presence of qnr genes were determined by PCR. The isolates carrying the qnr genes were used for bacterial conjugation tests to determine the presence of transferable plasmids. Antimicrobial susceptibility tests and PCR were carried out in the transconjugants to verify the transfer of the genes. Results: High levels of antimicrobial resistance to quinolones and beta-lactams were found among the isolates. We found that 33.6% of the isolates carry the qnrB gene and 0.9% qnr A gene. Of the 23 transconjugants, 20 showed to have qnrB gene, but none qnrA. Discussion: We concluded that the high frequency of qnr genes found in the enterobacteria isolates and their presence on transferable plasmids, complicate the use of quinolones for the treatment of bacterial infections, thus, a treatment plan should be designed with the rational use and the rotation of different types of antimicrobials, in order to avoid the selection of increasingly resistant strains.

Actualización en la prescripción de fluoroquinolonas / Update on the prescription of fluoroquinolones

Resumen: Las quinolonas o fluoroquinolonas son un grupo de antibióticos frecuentemente prescritos y de amplio espectro que actúan inhibiendo a las enzimas encargadas de la replicación, transcripción, reparación y recombinación del ADN bacteriano. El objetivo de este artículo es presentar una revisión sistemática de los antecedentes, farmacocinética y actividad microbiológica de las tres fluoroquinolonas más representativas en nuestro medio (ciprofloxacino, levofloxacino y moxifloxacino) en sus tres indicaciones actualmente autorizadas: infecciones de vías respiratorias inferiores, de vías urinarias, de piel y tejidos blandos.

Abstract: Quinolones or fluoroquinolones are a group of commonly prescribed and broad-spectrum antibiotics drugs that act by inhibiting the enzymes responsible for the bacterial DNA replication, transcription, repair and recombination. The aim of this article is to present a systematic review of the three most representative fluoroquinolones in our country (ciprofloxacin, levofloxacin and moxifloxacin) in their three authorized indications: lower respiratory tract infections, urinary tract infections, skin and soft tissues infections.

Mutaciones en la región determinante de resistencia a quinolonas (QRDR) del gen gyrA de Neisseria gonorrhoeae presente en muestras clínicas de hombres que tienen sexo con hombres

Neisseria gonorrhoeae resistente a quinolonas (QRNG) es un problema muy importante en salud pública por su rápido desarrollo de resistencia a quinolonas, por lo que la OMS recomienda reforzar la vigilancia de resistencia antimicrobiana para orientar el tratamiento. En Perú hay pocos reportes sobre vigilancia de QRNG, y menos aún trabajos relacionados a patrones de mutación. Este estudio busca encontrar mutaciones en la Región Determinante de Resistencia a Quinolonas (QRDR) del gen gyrA de N. gonorrhoeae a partir de 1096 muestras clínicas de orina e hisopados, colectadas entre 2012 y 2013, provenientes de 367 hombres que tuvieron sexo con hombres (HSH). Se detectaron 58 muestras positivas a N. gonorrhoeae en 45 HSH mediante el ensayo de APTIMA Combo 2, y 11 muestras positivas a QRNG de 11 HSH mediante PCR en Tiempo Real. Las bacterias resistentes a quinolonas fueron analizadas por secuenciamiento e identificamos que el patrón frecuente de mutación fue la doble mutación de Ser-91 a Phe y de Asp-95 a Gly en la QRDR del gen gyrA. En conclusión, estas dobles mutaciones en la secuencia QRDR del gen gyrA indicarían la presencia de N. gonorrhoeae con fenotipo resistente a quinolonas en muestras clínicas de HSH de Lima-Perú, resaltando que éste es el primer estudio hecho en Perú sobre esta población de alto riesgo

Neisseria gonorrhoeae resistant to quinolones (QRNG) becomes a very important problem in public health due to the development of rapid resistance to quinolones, which is why the WHO recommends reinforcing antimicrobial resistance monitoring to guide treatment. In Peru there are few reports on QRNG surveillance and still less work related to mutation patterns. This study aims to find mutations in the Determinant Region of Quinolone Resistance (QRDR) of the gyrA gene of N. gonorrhoeae from 1096 clinical samples of urine and swabs from 367 men who have sex with men (MSM) collected during the period 2012-2013. We detected 58 N. gonorrhoeae positive samples in 45 MSM by means of the APTIMA Combo 2 assay, and 11 QRNG positive samples of 11 MSM by Real Time PCR. The quinolone-resistant bacteria were analyzed by sequencing and we identified that the frequent mutation pattern was the double mutation of Ser-91 to Phe and Asp-95 to Gly in the QRDR of the gyrA gene. In conclusion, these double mutations in the QRDR sequence of the gyrA gene would indicate the presence of N. gonorrhoeae with quinolone resistant phenotype in clinical samples of MSM from Lima-Peru, noting that this is the first study done in Peru on this high population risk

Comparación entre ciprofloxacina y antibióticos de otros grupos farmacológicos para el tratamiento de infecciones del tracto urinario / Comparison between ciprofloxacine and antibiotics of other pharmacological groups for urinary tract infection treatment / Comparação entre a ciprofloxacina e outros antibióticos grupos farmacológicos para o tratamento de infecções do tracto urinário

ResumenIntroducción. Las infecciones de tracto urinario son un tema común en los servicios de consulta externa y emergencias de los centros de salud. El uso inadecuado e irracional de antibióticos puede favorecer la aparición de cepas resistentes y limitar la capacidad de respuesta de estos fármacos. Este artículo busca revisar el uso de quinolonas (específicamente ciprofloxacina) con antibióticos de otros grupos farmacológicos y comparar efectividad y resistencia bacteriana.Método. A partir de la metodología que señala la práctica clínica basada en la evidencia para las revisiones rápidas, se estableció una pregunta clínica a la que se le procuró responder mediante la búsqueda de investigaciones primarias en bases de datos electrónicas como MEDLINE, PubMed, Cochrane Library Plus y el Journal of Infection.Resultado. Según el tipo de bacteria y cepa analizada, hay presencia de resistencia a diversos antibióticos. Las infecciones de origen comunitario han sido tratadas con betalactámicos, nitrofurantoína, trimetoprimsulfametoxasol y fluoroquinolonas (especialmente ciprofloxacina).Conclusión. No se determinó si las quinolonas son más efectivas que los antibióticos que pertenecen a otros grupos farmacológicos

AbstractIntroduction. Urinary tract infections are a common reason of consultation in medical practical in ambulatory and emergency rooms in centers of health. The inadequate and irrational use of antibiotics can favor the appearance of resistant bacterial strain and limit the capacity of response of these medicines. This article seeks to review the use of quinolones (specifically ciprofloxacine) with antibiotics of other pharmacological groups and to compare efficiency and bacterial resistance.Method.From the methodology that indicates the clinical practice based on the evidence for the rapid reviews, there was established a clinical question to which response was tried to give by means of the search of primary investigations in electronic databases like MEDLINE, PubMed, Cochrane Library Plus and the Journal of Infection.Result. According to the type of bacterium and analyzed bacterial strain there is presence of resistance to diverse antibiotics. The infections of community origin have been treated by beta-lactamics, nitrofurantoine, trimetoprimsulfametoxasol and fluoroquinolones (specially ciprofloxacine).Conclusion. It was not possible to determine if the quinolonas are more effective than the antibiotics that belong to other pharmacological groups.

ResumoIntrodução. As infecções do trato urinário são um tema comum nos serviços de consulta externa e emergências dos centros de saúde. O uso inadequado e irracional de antibióticos pode favorecer o aparecimento de cepas resistentes e limitar a capacidade de resposta destes medicamentos. Este artigo busca revisar o uso de quinolonas (especificamente ciprofloxacina) com antibióticos de outros grupos farmacológicos e comparar efetividade e resistência bacteriana.Método. A partir da metodologia que aponta a prática clínica baseada na evidência para as revisões rápidas, se estabeleceu uma pergunta clínica que se procurou responder mediante pesquisas primárias em bases de dados eletrônicas como MEDLINE, PubMed, Cochrane Library Plus e o Journal of Infection.Resultado. Segundo o tipo de bactéria e cepa analisada, há presença de resistência a diversos antibióticos. As infecções de origem comunitária tem sido tratadas com betalactâmicos, nitrofurantoína, trimetoprimsulfametoxasol e fluoroquinolonas (especialmente ciprofloxacina).Conclusão. Não se determinou se as quinolonas são mais eficazes que os antibióticos que pertencem a outros grupos farmacológicos

Resistencia a aminoglucósidos y quinolonas en cepas de Klebsiella pneumoniae aisladas en dos unidades de cuidados intensivos del Hospital Universitario de Los Andes Mérida, Venezuela, entre 2007 y 2009 / Aminoglycoside and quinolone resistance in strains of Klebsiella pneumonia isolated from two units of intensive care unit of the University of the Andes Hospital, Merida, Venezuela between 2007 and 2009

Introducción: el incremento en la resistencia a aminoglucósidos y quinolonas es un grave problema para el tratamiento de las infecciones a nivel mundial. Sin duda uno de los factores que ha contribuido a este incremento, es la gran plasticidad que poseen para adquirir genes que le confieren resistencia a los antimicrobianos. Objetivo: determinar los patrones y genes de resistencia a aminoglucósidos y quinolonas en cepas de K. pneumoniae aisladas de dos unidades del Hospital Universitario de los Andes Mérida. Venezuela en 2007 y 2009. Materiales y Método: evaluaron 39 cepas de K. pneumoniae aisladas en la unidad de alto riesgo neonatal y unidad de cuidados intensivos de adultos. La sensibilidad antimicrobiana se determinó mediante la prueba de difusión del disco y por E-test. La detección de los genes aac(3)-IIa, aac(6)-Ib, arma, rmt, qnrA, qnrB y qnrS se realizó por PCR y posterior secuenciación. Resultados: el 100% de las cepas aisladas en 2007 portaban el gen aac(6)-Ib, mientras que el 57% de las cepas aisladas de la misma unidad y de la unidad de cuidados intensivos de adultos en el año 2009 portaban los genes de resistencia aac(3)-IIa, aac(6)-Ib. La resistencia a quinolonas se observó en el 88,8% de las cepas aisladas de la y portaban el gen qnrB. Conclusiones: la resistencia a los aminoglucósidos en las cepas aisladas en la unidad de alto riesgo neonatal estuvo mediada por los genes genes aac(3)-IIa y aac(6)-Ib. Mientras que la resistencia a quinolonas se presento en las cepas aisladas de la unidad de cuidados intensivos de adultos mediadas por el gen qnrB. MÉD.UIS. 2016;29(2):21-30.

Introduction: aminoglycoside and quinolone resistance is serious problem for the treatment of infections worldwide.Without doubtone of the factors that has contributed to the increase in the resistance in enterobacteria, is the great plasticity that possess the bacteria of this family to acquire genes that confers resistance to antimicrobials. Objective: to determine the patterns of resistance to aminoglycosides and quinolones in strains of Klebsiella pneumoniae isolated from two intensive care units of the Universidad de los Andes, Merida, Venezuela. Methods: weevalvated with 39 K. pneumoniae strains isolated in neonatal high risk unit and adult intensive care unit. Antibiotic susceptibility was tested by the disk diffusion method and by the E-test method. Detection of aac (3)-IIa, aac (6)-Ib, arma, rmt, qnrA, qnrS qnrB genes was carried out by PCR and subsequently sequenced. Results: 100 % of the strains isolated in 2007 were carriers of the gene aac(6)-Ib , while 57% of the strains isolated from the same unit and the in the year 2009 were carriers of resistance genes aac(3)-IIa, aac(6)-Ib. The resistance to quinolones were observed in the 88.8% of the strains of Klebsiella isolated from the AICU and were carriers the qnrB gene. Conclusions: the resistance to aminoglycosides in strains isolated in the neonatal high risk unit was mediated by genes aac(3)-IIa and aac(6)-Ib. While the resistance to quinolones was presented in the strains isolated from the adult intensive care unit mediated by the qnrB gene. MÉD.UIS. 2016;29(2):21-30.

Antimicrobial susceptibility of Salmonella Gallinarum and Salmonella Pullorum isolated from ill poultry in Brazil / Suscetibilidade a antimicrobianos de Salmonella Gallinarum e Salmonella Pullorum isolados de aves doentes no Brasil

ABSTRACT: Salmonella Gallinarum (S. Gallinarum) and Salmonella Pullorum (S. Pullorum) are poultry host-specific, agents of fowl typhoid and pullorum disease, respectively. These biovars cause septicemic infections, resulting in high mortality. Outbreaks are frequently reported worldwide, causing losses due to the elimination of infected flocks and treatments. The use of antimicrobial agents is frequent in poultry farms to prevent or treat gastrointestinal infections. In the present research it was evaluated the antimicrobial susceptibility of 50 S. Gallinarum and S. Pullorum isolates, from outbreaks that occurred between 1987 to 1991 and 2006 to 2013. The comparison of the susceptibility profiles showed that all isolates were susceptible to β-lactams. All isolates from 1987-1991 were susceptible to all antibiotics tested except NAL and CIP (78%). The susceptibility profile of S. Gallinarum (2006 - 2013 period) was the following NAL (58%), CIP (63%), ENR (67%), TET (92%), FFC (96%) and SXT (96%). S. Pullorum isolates (2006 - 2013 period) showed the following susceptibility rates to NAL (65%), CIP (71%), ENR (94%) and TET (94%). All isolates were susceptible to β-lactams tested, however, resistance to quinolones and fluoroquinolones increased over time. Furthermore, low levels of resistance to other antibiotics were found in recent isolates, such as tetracyclines.

RESUMO: Salmonella Gallinarum (S. Gallinarum) e Salmonella Pullorum (S. Pullorum) são patógenos hospedeiro-específico de aves, agentes do tifo aviário e pulorose, respectivamente. Estes biovares causam infecções septicêmicas, resultando em alta mortalidade. Surtos são frequentemente relatados em diversos países, causando prejuízos devido à eliminação de lotes infectados e tratamentos. Agentes antimicrobianos são utilizados frequentemente em granjas avícolas para prevenir ou tratar infecções gastrointestinais. No presente trabalho, foi avaliada a susceptibilidade antimicrobiana de 50 isolados de S. Gallinarum e S. Pullorum, obtidos durante surtos que ocorreram entre 1987 a 1991 e entre 2006 a 2013. A comparação dos perfis de sensibilidade mostrou que todas as amostras são sensíveis aos β-lactâmicos. Todos os isolados de 1987-1991 foram sensíveis a todos os antibióticos testados, exceto NAL e CIP (78%). O perfil de susceptibilidade de S. Gallinarum (surtos de 2006 a 2013) foi NAL (58%), CIP (63%), ENR (67%), TET (92%), FFC (96%) e SXT (96%). Isolados de S. Pullorum (surtos de 2006 a 2013) apresentaram as seguintes taxas de sensibilidade: NAL (65%), CIP (71%), ENR (94%) e TET (94%). Todas as amostras foram sensíveis ao β-lactâmicos testados, no entanto, a resistência às quinolonas e fluoroquinolonas aumentou ao longo do tempo. Além disso, baixos níveis de resistência a outros antibióticos foram encontrados em isolados recentes, tais como as tetraciclinas.

Quinolonas: Perspectivas actuales y mecanismos de resistencia / Quinolones: Nowadays perspectives and mechanisms of resistance

Quinolones are a family of synthetic broad-spectrum antimicrobial drugs whose target is the synthesis of DNA. They directly inhibit DNA replication by interacting with two enzymes; DNA gyrase and topoisomerase IV. They have been widely used for the treatment of several community and hospital acquired infections, in the food processing industry and in the agricultural field, making the increasing incidence of quinolone resistance a frequent problem associated with constant exposition to diverse microorganisms. Resistance may be achieved by three non-exclusive mechanisms; through chromosomic mutations in the Quinolone Resistance-Determining Regions of DNA gyrase and topoisomerase IV, by reducing the intracytoplasmic concentrations of quinolones actively or passively and by Plasmid-Mediated Quinolones-Resistance genes, [Qnr determinant genes of resistance to quinolones, variant gene of the aminoglycoside acetyltransferase (AAC(6')-Ib-c)] and encoding genes of efflux pumps (qepA and oqxAB)]. The future of quinolones is uncertain, however, meanwhile they continue to be used in an irrational way, increasing resistance to quinolones should remain as an area of primary priority for research.

Las quinolonas son un grupo de antimicrobianos sintéticos de amplio espectro, cuyo objetivo es la síntesis del ADN. Inhiben directamente su replicación al interactuar con dos enzimas; ADN girasa y topoisomerasa IV. Se han utilizado ampliamente para el tratamiento de infecciones intra y extra-hospitalarias, en el campo de la agricultura y en el procesamiento de alimentos, lo que hace que el incremento de resistencia a quinolonas sea un problema cada vez más frecuente, asociado a la constante exposición de diversos microorganismos. La resistencia puede alcanzarse mediante tres mecanismos no excluyentes entre sí; a través de mutaciones cromosómicas en genes codificantes que afectan las regiones determinantes de resistencia a quinolonas de ADN girasa y topoisomerasa IV, al reducir las concentraciones intracitoplásmicas de quinolonas de manera activa o pasiva y por genes de resistencia a quinolonas mediados por plásmidos [genes de resistencia a quinolonas determinates de qnr, gen variante de la aminoglucósido acetil transferasa (AAC(6’)-lb-cr) y genes codificadores de bombas de eflujo (qepAy oqxAB)]. El futuro de las quinolonas es incierto; sin embargo, mientras continúen empleándose para el manejo de infecciones en el ser humano, el incremento de resistencia a quinolonas debe permanecer como un área de importancia primaria para la investigación.

Detecção de resistência às fluoroquinolonas em Campylobacter isolados de frangos de criação orgânica / Detection of fluoroquinolone resistance in Campylobacter strains from organic poultry

Estudos têm revelado que a resistência às quinolonas em cepas de Campylobacter está relacionada à presença da mutação Treonina-86 para Isoleucina. Com o objetivo de investigar a presença dessa mutação em cepas de Campylobacter sensíveis e resistentes à ciprofloxacina e enrofloxacina, o conteúdo cecal de 80 frangos de corte de criação orgânica, abatidos sob Serviço de Inspeção Estadual (S.I.E.) do Estado do Rio de Janeiro, foram coletados e investigados para a presença de Campylobacter. A determinação da resistência à ciprofloxacina e enrofloxacina foi feita pela técnica de difusão em disco e de diluição em ágar para determinação da Concentração Inibitória Mínima (CIM). A detecção da mutação na Região Determinante de Resistencia às Quinolonas (RDRQ) no gene gyrA foi realizada através de sequenciamento. Campylobacter foi isolado a partir de 100% das amostras avaliadas, sendo 68,75% correspondente à C. jejuni e 31,25% à C. coli. No teste de difusão em disco, 100% das cepas foram resistentes à ciprofloxacina e 56,25% das cepas foram resistentes à enrofloxacina. No teste de diluição em ágar, todas as cepas foram resistentes à ciprofloxacina apresentando CIM variando de ≥ 16-64μg/mL, e resistência ou resistência intermediaria à enrofloxacina foi detectada em 42,50% (CIM ≥ 4-32μg/mL) e 38,75% (CIM = 2μg/mL) das cepas, respectivamente. A mutação Tre-86-Ile, foi observada em 100% das cepas analisadas. Além dessa mutação, foram observadas outras mutações não silenciosas (Val-73-Glu, Ser-114-Leu, Val-88-Asp, Ala-75-Asp, Ser-119-Gli, Arg-79-Lis) e mutações silenciosas (His-81-His, Ser-119-Ser, Ala-120-Ala, Fen-99-Fen, Ala-122-Ala, Gli-74-Gli, Ile-77-Ile, Ala-91-Ala, Leu-92-Leu, Val-93-Val, Ile-106-Ile, Tre-107-Tre, Gli-113-Gli, Ile-115-Ile, Gli-110-Gli). A observação de que cepas sensíveis à enrofloxacina pelos testes fenotípicos apresentavam a substituição Tre-86 para Ile sugere que outros mecanismos podem contribuir para a resistência à enrofloxacina em Campylobacter...

Studies have shown that resistance to quinolones in Campylobacter strains is related with Threonine-86-Isoleucine mutation. In order to investigate the presence of this mutation in sensitive and resistant Campylobacter strains to ciprofloxacin and enrofloxacin, the cecal contents of 80 broilers from organic raising chickens, slaughtered under State Inspection Service (S.I.S) of the State of Rio de Janeiro, were collected and tested for the presence of Campylobacter. The determination of ciprofloxacin and enrofloxacin susceptibility was done by disk diffusion and agar dilution methods for determining the Minimum Inhibitory Concentration (MIC). The detection of mutation in Quinolone Resistance Determinant Region (QRDR) in gyrA gene was done by sequencing. Campylobacter was isolated from 100% of the samples, being 68.75% C. jejuni and 31.25% C. coli. By the disk diffusion method, resistance to ciprofloxacin was observed in all isolates and 56.25% of the strains were resistant to enrofloxacin. By agar dilution method, all strains were resistant to ciprofloxacin (MIC ≥ 16μg/mL to ≥ 64μg/mL) and full and intermediate resistance to enrofloxacin was detected in 42.50% (MIC ≥ 4-32μg/mL) and 38.75% (MIC =2μg/mL) of the strains, respectively. Mutation Thr-86-Ile was observed in 100% of the isolates investigated. In addition to this mutation, others no silent mutations (Val-73-Glu, Ser-114-Leu, Val-88-Asp, Ala-75-Asp, Gly-119-Ser, Arg-79-Lys) and silent mutations (His-81-His, Ser-119-Ser, Ala-120-Ala, Phe-99-Phe, Ala-122-Ala, Gly-74-Gly, Ile-77-Ile, Ala-91-Ala, Leu-92-Leu, Val-93-Val, Ile-106-Ile, Thr-107-Thr, Gly-113-Gly, Ile-115-Ile, Gly-110-Gly) were detected. All the enrofloxacin-sensitive strains by the phenotypic methods had the Thr-86 to Ile substitution, which suggests other mechanisms contributing to enrofloxacin resistance in Campylobacter...

Risk factors for infection with carbapenem-resistant Klebsiella pneumoniae: a case-case-control study / Factores de riesgo para infección con Klebsiella pneumoniae resistente a carbapenémicos: estudio caso-caso-control

Objective: To evaluate the association between quinolone exposure and the emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and to estimate CRKP-specific mortality. Methods: Case-case-control study implemented in a tertiary care institution. Three groups of patients were analyzed: 61 consecutive cases of infection with CRKP (Group I); 61 randomly chosen cases of patients infected with carbapenem-sensitive Klebsiella pneumoniae (CSKP; Group II); and 122 randomly chosen controls without CRKP or CSKP infection. Matching was based on the length of stay in intensive care unit and the date of bacterial isolation. An active search was performed for patients with CRKP and CSKP infection, and prospective cases were included in the study. We compared the results for Groups I and II against those for the controls by using two conditional logistic regression analyses that included infection as the dependent variable and controlled for time at risk and co-morbidities. Results: Exposure to quinolones was not associated with CRKP infection: no association was found in the analysis of CRKP with the controls (OR = 1.7; 95% CI: 0.2-6.5) or in the analysis of CSKP against the controls (OR = 0.6; 95% CI: 0.2-1.6). Use of carbapenems (OR = 3.3; 95% CI: 1.2-9.3) and colonization with CRKP (OR = 3.3; 95% IC: 1.2-9.3) were specific risk factors for infection with CRKP. Mortality associated with CRKP was 61.3%. Conclusion: No association was found between exposure to quinolones and infection with CRKP; however, colonization by CRKP and use of carbapenems are risk factors for infection with CRKP.

Resumen Objetivo: Evaluar la asociación entre la exposición a quinolonas y la aparición de infección por Klebsiella pneumoniae resistente a Carbapenémicos (CRKP) y estimar la mortalidad específica por CRKP. Métodos: Estudio caso-caso-control realizado en una institución de tercer nivel de atención. Se adelantó búsqueda activa y prospectiva de los casos. Se analizaron tres grupos: 61 casos consecutivos de infección por CRKP, 61 casos elegidos al azar de los pacientes con infección por Klebsiella pneumoniae sensible a Carbapenémicos (CSKP) y 122 controles sin infección por CRKP ni por CSKP, elegidos al azar. Se realizó emparejamiento por estancia en unidad de cuidados intensivos y fecha del aislamiento bacteriano. Los datos se extractaron de la historia clínica electrónica. Se comparó los casos CRKP y los casos CSKP contra los controles mediante dos análisis de regresión logística condicional, con la infección como variable dependiente y controlando por el tiempo en riesgo y la comorbilidad. Resultados: La exposición a quinolonas no se asoció a infección con CRKP: no se encontró asociación en el análisis de CRKP contra controles (OR 1.7 IC 95%: 0.2-6.5) ni en el análisis de CSKP contra controles (OR 0.6 IC 95%: 0.2-1.6). El uso de carbapenémicos (OR 3.3 IC 95%: 1.2-9.3) y la colonización por KPRC (OR 16,2 IC 95%: IC 95%: 3.3-79.1) fueron factores de riesgo específicos para infección por CRKP. La mortalidad específica asociada a CRKP fue de 61.3%. Conclusión: No se encontró asociación entre la exposición a quinolonas y la infección por KPRC, pero la colonización por CRKP y el uso de carbapenémicos son factores de riesgo asociados a la infección por KPRC.

Caracterización molecular de la región determinante de resistencia a quinolonas (QRDR) de la topoisomerasa IV de Bartonella bacilliformis en aislados clínicos

Bartonella bacilliformis es el agente etiológico de la Enfermedad de Carrión, endémica del Perú. Pocas investigaciones han sido realizadas acerca de los genes asociados a la resistencia antimicrobiana en aislados clínicos de este patógeno. Estos genes no están caracterizados molecularmente, ni se conoce la región asociada a dicha resistencia. Por ello, el objetivo del este trabajo fue caracterizar molecularmente la región determinante de la resistencia a las quinolonas (QRDR) en la topoisomerasa IV, que está codificada por los genes parC y parE, así como también desarrollar una prueba de susceptibilidad antimicrobiana para B. bacilliformis. Las muestras sanguíneas de 65 pacientes procedentes de La Libertad, Cusco, Ancash y Piura, se sembraron en placas de agar sangre e incubaron a 30 °C con 5% CO2. Luego se procedió a: (1) determinar la susceptibilidad antimicrobiana y (2) extraer el DNA genómico, amplificar los genes mencionados, secuenciarlos y analizarlos mediante herramientas bioinformáticas. Se obtuvieron 6 cultivos positivos. Los aislados fueron sensibles a la ciprofloxacina (excepto uno procedente de Quillabamba-Cusco, que presentó susceptibilidad disminuida) y resistentes al ácido nalidíxico. Del análisis de las secuencias aminoacídicas de ParC y ParE de B. bacilliformis se concluye que presentan diferencias aminoacídicas en comparación con las secuencias de las proteínas respectivas de E. coli K12 MG1655, que probablemente confieran resistencia al ácido nalidíxico pero no a la ciprofloxacina. Se determinó que las QRDR de las proteínas ParC y ParE de B. bacilliformis están comprendidas entre los aminoácidos 67 al 118 y 473 al 530, respectivamente. El antibiograma y la concentración mínima inhibitoria se evalúan mejor usando inóculos a escala 1 de McFarland y a los 6 días de incubación

Bartonella bacilliformis is the etiologic agent of Carrion's disease, which if endemic to Peru. Studies on antimicrobial resistance genes from clinical isolates of this pathogen are scarce, and the molecular characteristics of these genes and their region resistance-associated are currently unknown. In this work we made the molecular characterization of the quinolone-resistance, and establish the region (QRDR) for the topoisomerase IV, which is encoded by the parC and parE genes, as well as develop an antimicrobial susceptibility test for B. bacilliformis. 65 Blood samples from La Libertad, Cusco, Ancash and Piura were processed on Blood Agar plates and incubated at 30 °C, 5% CO2. The antimicrobial susceptibility was determined, then the genomic DNA extracted, aforementioned genes amplified, their sequence determined and it analyzed using bioinformatics tools. Six positive cultures were obtained. The isolates were susceptible to Ciprofloxacin (except one strain from Quillabamba _ Cusco, which showed decreased susceptibility) and were resistant to Nalidixic Acid. From the sequence analysis of B. bacilliformis ParC and ParE there have been shown amino acid differences compared to the respective protein sequences from E. coli K12 MG1655, which is likely to confer resistance to Nalidixic Acid but not to Ciprofloxacin. It was determined that B. bacilliformis ParC and ParE proteins QRDRs are comprised between amino acids 67 to 118 and 473 to 530, respectively. The antibiogram and the minimal inhibitory concentration are best assessed using the #1 McFarland standards after a 6-day incubation period

Pesquisa de genes de resistência a quinolonas em bacilos Gram negativos de origem clínica e ambiental / Research for genes of quinolone resistance in Gram negative bacilli from clinical and environmental origin

Introdução. Quinolonas são antimicrobianos sintéticos que inibem as enzimas DNA-girase e topoisomerase IV resultando na morte bacteriana. São altamente eficazes no tratamento de infecções bacterianas, especialmente causadas por bactérias Gram negativas, e portanto amplamente utilizados na medicina humana e veterinária, na qual também são empregados como profiláticos. Porém, o uso indiscriminado e inadequado levou ao aumento de bactérias resistentes a estes compostos. Esta resistência pode ocorrer devido a mutações nas enzimas DNA-girase e topoisomerase IV, e também por genes contidos em plasmídeos. Estes últimos são os principais responsáveis pela disseminação e circulação da resistência entre o meio ambiente e o ambiente hospitalar. Objetivos. Pesquisar genes de resistência a antimicrobianos do grupo das quinolonas em bactérias Gram negativas de origem clínica e ambiental que apresentam resistência fenotípica a este grupo. Material e Métodos. 73 cepas de Enterobacteriaceae e Aeromonas sp. de origem clínica e ambiental foram selecionadas para o estudo, e avaliadas quanto à sensibilidade aos antimicrobianos do grupo das quinolonas e à pesquisa de genes de resistência a este mesmo grupo e mutações no gene que codifica a enzima DNA-girase por meio de PCR e sequenciamento. Resultados. Das 73 cepas previamente selecionadas para compor o estudo, 65 foram utilizadas, devido à exclusão de perfis clonais similares. Nestas, foram observados os genes, qnrS1 (1,5 por cento ), qnrS2 (26,2 por cento ), qnrB1 (3,1 por cento ), qnrB19 (12,3 por cento ), qnrD1 (1,5 por cento ), aac(6)-Ib-cr (10,8 por cento ), oqxA (43,1 por cento ) e oqxB (41,5 por cento ), e duas variantes determinadas qnrB-like (3,1 por cento ) e qnrB69-like (1,5 por cento ). Os genes qnrA, qnrC e qepA não foram identificados. Mutações na enzima DNA-girase foram observadas em 97,9 por cento das cepas positivas para algum dos genes pesquisados...

Introduction. Quinolones are synthetic antimicrobial agents that inhibit DNA gyrase and topoisomerase IV enzymes resulting in bacterial death. They are highly effective in the treatment of bacterial infections, especially the ones caused by Gram negative bacteria, as well as for prophylaxy. Therefore they are widely used in human and veterinary medicine. However, indiscriminate and improper use led to an increase of bacteria resistance to these compounds. This resistance can be due to mutations in DNA gyrase and topoisomerase IV enzymes and also by genes contained in plasmids, which are mainly responsible for the spread and transmission of resistance between the environment and the hospital set. Objectives. To search for genes of resistance to quinolone antimicrobial agents in Gram-negative bacteria from clinical and environmental strains that present phenotypic resistance to this group. Material and Methods. 73 strains of Enterobacteriaceae and Aeromonas spp., from clinical and environmental origin, were selected for this study, and evaluated for antimicrobial susceptibility of quinolone and search of resistance genes in this same group and also for mutations in the gene encoding the enzyme DNA gyrase by PCR and sequencing. Results. Of the 73 strains previously selected to compose this study, 65 were used, due to the exclusion of similar clonal profiles. In these, genes qnrS1 (1.5 per cent ), qnrS2 (26.2 per cent ) qnrB1 (3.1 per cent ), qnrB19 (12.3 per cent ) qnrD1 (1.5 per cent ) aac(6')-Ib-cr (10.8 per cent ) oqxA (43.1 per cent ) and oqxB (41.5 per cent ) were observed, and two variants were named as qnrB-like (3.1 per cent ) and qnrB69-like (1.5 per cent ). The qnrA, qnrC and qepA genes were not identified. Mutations in DNA gyrase enzyme were observed in 97.9 per cent of the positive strains for at least one of the genes studied. It was possible to establish the association of aac(6')-Ib-cr with class 1 integron gene in four strains...