Impact of the national shortage of polymyxin B in critically ill patients during the COVID-19 pandemic / Impacto da escassez nacional de polimixina B em pacientes gravemente enfermos durante a pandemia de COVID-19 / Impacto del desabasto nacional de polimixina B en pacientes críticos durante la pandemia de COVID-19

Background and Objectives: during the COVID-19 pandemic, the number of critical patients requiring intensive care increased considerably, resulting in an increase in infections due to multi-resistant microorganisms. In Brazil, in 2021, due to the high demand for polymyxin B use, there was a national shortage of the medication. One strategy used to overcome this situation was aminoglycoside use. The work aimed to analyze the impact of replacing polymyxin B with amikacin and gentamicin in the final stage of patients. Method: an analytical study with an observational, cross-sectional design, with a quantitative approach, through a retrospective analysis through the analysis of medical records, with the primary stages being discharges or deaths. Results: mortality was similar between the group treated with aminoglycoside and the group treated with polymyxin B. Within the aminoglycoside group, mortality was higher in the group that had bacteria resistant to the drug than in the group that had infection with an organism sensitive to this drug. Mortality was not affected by comorbidities, age, or number of hospital infections. The main factor that led to the need for dialysis was the combination of two nephrotoxic medications. Conclusion: two hypotheses emerged: the first would be that replacing polymyxin B with aminoglycosides did not impact mortality; the other would be that, regardless of the antibiotic group used, patients had a high risk of death. Despite sample limitations, the study corroborates the adoption of strategies for the rational use of antimicrobials.(AU)

Justificativa e Objetivos: durante a pandemia de COVID-19, o número de pacientes críticos que necessitaram de cuidados intensivos aumentou consideravelmente, resultando em aumento de infecções por microrganismos multirresistentes. No Brasil, em 2021, devido à grande demanda pelo uso da polimixina B, houve escassez nacional do medicamento. Uma estratégia utilizada para superar essa situação foi o uso de aminoglicosídeos. O trabalho teve como objetivo analisar o impacto da substituição da polimixina B por amicacina e gentamicina na fase final dos pacientes. Método: estudo analítico com desenho observacional, transversal, com abordagem quantitativa, por meio de análise retrospectiva por meio de análise de prontuários, sendo as etapas primárias as altas ou óbitos. Resultados: a mortalidade foi semelhante entre o grupo tratado com aminoglicosídeo e o grupo tratado com polimixina B. Dentro do grupo aminoglicosídeo, a mortalidade foi maior no grupo que apresentava bactérias resistentes ao medicamento do que no grupo que apresentava infecção por organismo sensível a este medicamento. medicamento. A mortalidade não foi afetada por comorbidades, idade ou número de infecções hospitalares. O principal fator que levou à necessidade de diálise foi a combinação de dois medicamentos nefrotóxicos. Conclusão: surgiram duas hipóteses: a primeira seria que a substituição da polimixina B por aminoglicosídeos não impactou a mortalidade; a outra seria que, independentemente do grupo de antibióticos utilizado, os pacientes apresentavam alto risco de morte. Apesar das limitações amostrais, o estudo corrobora a adoção de estratégias para o uso racional de antimicrobianos.(AU)

Antecedentes y Objetivos: durante la pandemia de COVID-19, el número de pacientes críticos que requirieron cuidados intensivos aumentó considerablemente, resultando en un aumento de infecciones por microorganismos multirresistentes. En Brasil, en 2021, debido a la alta demanda del uso de polimixina B, hubo escasez nacional del medicamento. Una estrategia utilizada para superar esta situación fue el uso de aminoglucósidos. El trabajo tuvo como objetivo analizar el impacto de la sustitución de la polimixina B por amikacina y gentamicina en la etapa final de los pacientes. Método: estudio analítico con diseño observacional, transversal, con enfoque cuantitativo, mediante un análisis retrospectivo mediante el análisis de historias clínicas, siendo las etapas primarias las altas o defunciones. Resultados: la mortalidad fue similar entre el grupo tratado con aminoglucósido y el grupo tratado con polimixina B. Dentro del grupo de aminoglucósido, la mortalidad fue mayor en el grupo que tenía bacterias resistentes al fármaco que en el grupo que tenía infección con un organismo sensible a este. droga. La mortalidad no se vio afectada por las comorbilidades, la edad o el número de infecciones hospitalarias. El principal factor que llevó a la necesidad de diálisis fue la combinación de dos medicamentos nefrotóxicos. Conclusión: surgieron dos hipótesis: la primera sería que la sustitución de polimixina B por aminoglucósidos no impactó la mortalidad; la otra sería que, independientemente del grupo de antibióticos utilizado, los pacientes tenían un alto riesgo de muerte. A pesar de las limitaciones de la muestra, el estudio corrobora la adopción de estrategias para el uso racional de antimicrobianos.(AU)

Eficacia de la terapia con aminoglicósidos en infectados por Klelsiella pneumoniae resis-tente a carbapenémicos / Efficacy of aminoglycoside therapy in patients infected with Carbapenem-Resistant Klel-siella pneumoniae

El tratamiento de infecciones por bacterias resistentes a determinados grupos farmacológicos resulta un tema de alto interés para la ciencia. Así, la investigación tuvo el propósito de sistema-tizar la información acerca de la eficacia de los aminoglicósidos en pacientes infectados por Klebsiella pneumoniae resiste a carbapenémicos; para lo que se hizo una revisión sistemática siguiendo el protocolo PRISMA. Las fuentes se ubicaron a partir de una pesquisa se hizo en las bases de datos: PubMed, MEDLINE y SCOPUS; quedando seleccionados 11 artículos que cumplieron con los requisitos establecidos. Se observó un predominio de los artículos provenientes de los Estados Unidos de América (4/11) y Brasil (3/11). La población global fue de 3778 pacientes entre las 11 investigaciones incluidas. El uso de aminoglicósidos resultó más eficaz que otros grupos farmacológicos en la mejoría en el estado clínico, reflejando menores valores de mortalidad en pacientes hospitalizados por la infección en cuestión.

The treatment of infections by bacteria resistant to certain pharmacological groups is a topic of great interest for science. Thus, the research had the purpose of systematizing the information about the efficacy of aminoglycosides in patients infected by Carbapenem-Resistant Klebsiella pneumoniae. This systematic review was carried out following the PRISMA protocol. The sour-ces were located from a search made in the databases: PubMed, MEDLINE, and SCOPUS; 11 articles were selected that met the established requirements. A predominance of articles from the United States of America (4/11) and Brazil (3/11) was observed. The overall population was 3,778 patients among the 11 studies included. The use of aminoglycosides was more effective than other pharmacological groups in improving clinical status, reflecting lower mortality values in patients hospitalized for the infection in question

Factores asociados a infección de vías urinarias luego de una prostatectomía / Factors Associated with Urinary Tract Infection after Prostatectomy

Introducción y Objetivo La cirugía de próstata es un procedimiento frecuente en varones mayores. Existen diferentes técnicas, cuya elección depende de la patología a tratar, de la experiencia del especialista, y de la disponibilidad técnica. Entre sus complicaciones se encuentra la infección del tracto urinario, que ocasiona incremento en morbimortalidad y costos para el sistema de salud. El objetivo principal de este estudio fue evaluar los factores relacionados con la aparición de infección urinaria luego de este tipo de cirugía. Materiales y Métodos Se realizó un estudio de casos y controles en una población de pacientes sometidos a prostatectomía del 2018 hasta principios del 2020 en Medellín, Colombia. Los casos correspondieron a los pacientes que presentaron infección de vías urinarias hasta 30 días tras la prostatectomía. Se estimó la asociación entre casos y controles por medio del cálculo de la razón de disparidad (RD), la cual se ajustó con una regresión logística y con un modelo aditivo generalizado multivariado. Resultados Se identificaron 96 casos incidentes de infección del trato urinario luego de la prostatectomía, con una prevalencia de 8.99%. La frecuencia de solicitud de urocultivo preoperatorio fue de 52,92% (intervalo de confianza del 95% [IC95%]: 48,34­ 57,44%). Las variables independientemente asociadas con la aparición de infección urinaria fueron: solicitud de urocultivo prequirúrgico, número de dosis, y tipo de antibiótico usado para la profilaxis. Particularmente, se encontró como factor protector el uso de aminoglucósidos. En los pacientes con infección urinaria, los principales gérmenes aislados fueron: Eschirichia coli, Pseudomonas aeruginosa, Klepsiella pneumoniae, Enterococos faecalis y Serratia marcescens.

Introduction and Objective Prostate surgery is a common procedure among older men. There are different techniques, and the choice depends on the pathology to be treated, the experience of the specialist, and the technical availability. Among its complications is urinary tract infection, which causes increased morbidity and mortality and costs for the health system. The main objective of the present study was to evaluate the factors related to the onset of urinary tract infection after prostate surgery. Materials and Methods A case-control study was conducted in a population of patients undergoing prostatectomy from 2018 to early 2020 in the city of Medellín, Colombia. The cases corresponded to patients who presented urinary tract infection up to 30 days after prostatectomy. The association between cases and controls was estimated by calculating the odds ratio (OR), which was adjusted with logistic regression and a multivariate generalized additive model. Results We identified 96 incident cases of urinary tract infection after prostatectomy, with a prevalence of 8.99%. The frequency of requests for preoperative urine culture was of 52.92% (95% confidence interval [95%CI]: 48.34 - 57.44). The independently associated variables were: request for preoperative urine culture, number of doses, and type of antibiotic used for prophylaxis. In particular, the use of aminoglycosides in prophylaxis schemes was found to be a protective factor. The main germs isolated were: Eschirichia coli, Pseudomonas aeruginosa, Klepsiella pneumoniae, Enterococos faecalis, and Serratia marcescens. Conclusion The present study shows that factors such as the preoperative request for urine culture and the use of aminoglycosides for surgical prophylaxis influence the probability of developing urinary tract infection after prostatectomy.

Infección de piel y tejidos blandos por Burkholderia stabilis en un niño con quemaduras graves / Skin and soft tissue infection due to Burkholderia stabilis in a severely burned child

Resumen Las heridas por quemadura representan un grave problema, sobre todo en la población pediátrica, dada la severidad de su presentación y la morbimortalidad asociada. La infección es la complicación más frecuente y grave en el paciente quemado. Las bacterias que conforman el complejo Burkholderia cepacia (CBc) son capaces de causar enfermedades en plantas, humanos y animales. En el hombre pueden establecer infecciones crónicas y frecuentemente graves, por lo general en pacientes con fibrosis quística y en inmunocomprometidos. El CBc está compuesto por al menos 22 especies filogenéticamente muy relacionadas. El objetivo de esta publicación fue describir el primer caso de una infección de piel y partes blandas por Burkholderia stabilis, una especie poco frecuente, en un niño con grandes quemaduras en la Argentina. Las especies del CBc son intrínsecamente resistentes a la mayoría de los antimicrobianos disponibles clínicamente, como aminoglucósidos, quinolonas, polimixinas y β-lactámicos. Esto representa un serio problema en el momento de tratar las infecciones por las escasas opciones terapéuticas.

Abstract Burn wounds represent a serious problem, especially in the pediatric population, given the severity of their presentation and the associated morbidity and mortality. Infection is the most frequent and serious complication in the burned patient. Burkholderia cepacia (CBc) complex bacteria are capable of causing disease in plants, humans, and animals. In human beings they can establish chronic and frequently serious infections, generally in patients with cystic fibrosis and in immunocompromised patients. The CBc is composed of 22 phylogenetically closely related species. The objective of this publication was to describe the first report of a skin and soft tissue infection by Burkholderia stabilis, a rare species, in a child with extensive burns in Argentina. CBc species are inherently resistant to most clinically available antimicrobials, such as aminoglycosides, quinolones, polymyxins, and β-lactams. This represents a serious problem when treating infections, due to the limited therapeutic options.

Resumo As feridas por queimadura representam um grave problema, principalmente na população pediátrica, devido à gravidade de sua apresentação e morbimortalidade associada. A infecção é a complicação mais frequente e grave do paciente queimado. As bactérias que compõem o complexo Burkholderia cepacia (CBc) são capazes de causar doenças em plantas, humanos e animais. No homem, podem estabelecer infecções crônicas e freqüentemente graves, geralmente em pacientes com fibrose cística e imunocomprometidos. O CBc é composto, no mínimo, por 22 espécies filogeneticamente muito relacionadas. O objetivo desta publicação é descrever o primeiro caso de uma infecção de pele e tecidos moles por Burkholderia stabilis, uma espécie rara, em uma criança com queimaduras extensas na Argentina. As espécies do CBc são inerentemente resistentes à maioria dos antimicrobianos disponíveis clinicamente, como aminoglicosídeos, quinolonas, polimixinas e β-lactâmicos. Isso representa um problema sério na hora de tratar as infecções devido às opções terapêuticas limitadas.

Caracterização molecular dos mecanismos de resistência, perfil de virulência e diversidade genética de cepas de Salmonella Heidelberg / Molecular characterization of resistance mechanisms, virulence profile and genetic diversity of Salmonella Heidelberg strains

Salmonella spp. são os mais frequentes agentes causadores de surtos de origem alimentar sendo tipicamente encontrado em aves, e o sorotipo Heidelberg ganhou destaque entre esses isolados. Nos últimos anos, o aumento da resistência antimicrobiana verificada em Salmonella, principalmente no sorotipo Heidelberg tem sido de grande interesse em saúde pública em nível Nacional. Diante desta prioridade, o presente estudo teve como objetivo caracterizar a diversidade genética, verificar a presença de fatores de virulência e os perfis fenotípicos e genotípicos de resistência aos antimicrobianos em 32 isolados de S. Heidelberg. O teste de sensibilidade aos antimicrobianos foi determinado pela técnica de disco-difusão. Os isolados foram geneticamente comparados pela técnica de pulsed-field gel electrophoresis (PFGE). A técnica do sequenciamento do genoma completo (WGS) permitiu a pesquisa dos fatores de virulência, dos genes adquiridos e mutações pontuais presentes em genes cromossomais associados a mecanismos de resistência. Além disso, os isolados também foram caracterizados pelas técnicas de Multi-Locus Sequence Typing (MLST), análise de single-nucleotide polymorphisms (SNPs) e core genome MLST (cgMLST). Vinte e seis isolados (81,3%) apresentaram resistência a três ou mais diferentes classes de antimicrobianos. A técnica de PFGE demonstrou 80,4% de similaridade entre os isolados, e os agrupou em 21 diferentes pulso-tipos. A pesquisa de genes de virulência resultou na presença de vários fatores em todos os isolados entre eles: Lpf¸ MisL, RatB, MgtBC, sifA, ssaR, invA, sopB e fljB. Foram detectados genes de resistência a ß-lactâmicos blaCMY-2 (n=20/62,5%) e blaCTX-M-2 (n=2/6,3%), a aminoglicosídeos aac(3)-Via (n=3/9,4%), aac(6')-Iaa (n=32/100%) e aadA1 (n=4/ 12,5%), a tetraciclinas tet(A) (n=25/78,1%) e a sulfonamidas sul2 (n=25/78,1%). Entre os isolados que apresentaram mutações pontuais, 26 (81,3%) apresentaram em gyrA (p.S83F) e 30 isolados (93,8%) em parC (p.T57S). A caracterização in silico dos plasmídeos demonstrou a presença...(AU)

Synergy in penicillin, cephalosporin, amphenicols, and aminoglycoside against MDR S. aureus isolated from Camel milk

Abstract This study investigated the synergy testing of penicillin, cephalosporin, amphenicols, and aminoglycoside in the camel milk (n=768 samples), subsequently used for isolation of MDR S. aureus targeting mecA gene. Antibiotic susceptibility of S. aureus showed >90% isolates were sensitive to ciprofloxacin and trimethoprim and resistant against oxacillin, ampicillin, and cefoxitin. Further, 50-85% of the S. aureus were sensitive to gentamicin, oxytetracycline, and chloramphenicol and resistant against cefotaxime, vancomycin, and cefixime. Minimum inhibitory concentration (MIC) of cefotaxime, (C) and ampicillin (A) in combination with gentamicin (G) was reduced by 99.34% and 70.46%, respectively, while with chloramphenicol (Ch), reduction was 57.49% and 60%, respectively. In addition, the Fractional Inhibitory Concentration Index (FICI) of G+A, Ch+C and Ch+G combinations showed synergy against 80%, 60%, and 30% of MDR S. aureus, respectively. Similarly, C+A and Ch+G displayed indifferent interaction against 70 % and 30% of isolates, respectively, while the later showed additive interaction against 10% of MDR S. aureus. Altogether, our results described effective combination of gentamicin and chloramphenicol with ampicillin and cefotaxime to combat MDR S. aureus

Comparative application of biological and ninhydrin- derivatized spectrophotometric assays in the evaluation and validation of amikacin sulfate injection

Abstract Instrumental techniques are preferred over bioassay methods for antibiotic quantification mainly due to speed and ability to quantify metabolites in biological samples; however, the potency and biological activity of these drugs cannot be assessed. Two methods - agar well diffusion (bio-assay) and spectrophotometric methods were used to evaluate amikacin sulfate injection. Agar plates were inoculated with S. aureus inoculum; zones of inhibition from its susceptibility to amikacin were obtained, while spectrophotometric absorption at 650 nm of ninhydrin- derivatized amikacin in phosphate buffer (pH 8) was measured. Methods performance showed linearity from 1 - 16 µgmL-1 (bioassay, r = 0.9994) and 10-50 µgmL-1 (spectrophotometric, r = 0.9998). Molar absorptivity was 2.595 x 104 Lmol-1cm-1. Limits of detection and quantification were 1.07 and 3.24 µgmL-1 respectively for bioassay method, while corresponding values for spectrophotometric method were 0.98 and 2.97 µg mL-1. Relative standard deviations were ≤ 2.0% for both methods, with recoveries from 95.93 - 100.25%. Amikacin in brands ranged from 97.53 ± 2.68 to 100.84 ± 1.82%, student's t-test was ≤ 2.78 (n = 4) with respect to label claim for both methods. Experimental paired t-test (t = 2.07; n = 4) and F-test (F = 3.94; n = 4) values indicated no significant difference between both methods, hence comparable and can jointly be used in quality control assessment of antibiotics

Role of aminoglycoside-modifying enzymes and 16S rRNA methylase (ArmA) in resistance of Acinetobacter baumannii clinical isolates against aminoglycosides

Abstract INTRODUCTION: This study aimed to determine the role of genes encoding aminoglycoside-modifying enzymes (AMEs) and 16S rRNA methylase (ArmA) in Acinetobacter baumannii clinical isolates. METHODS: We collected 100 clinical isolates of A. baumannii and identified and confirmed them using microbiological tests and assessment of the OXA-51 gene. Antibiotic susceptibility testing was carried out using disk agar diffusion and micro-broth dilution methods. The presence of AME genes and ArmA was detected by PCR and multiplex PCR. RESULTS: The most and least effective antibiotics in this study were netilmicin and ciprofloxacin with 68% and 100% resistance rates, respectively. According to the minimum inhibitory concentration test, 94% of the isolates were resistant to gentamicin, tobramycin, and streptomycin, while the highest susceptibility (20%) was observed against netilmicin. The proportion of strains harboring the aminoglycoside resistance genes was as follows: APH(3′)-VIa (aphA6) (77%), ANT(2")-Ia (aadB) (73%), ANT(3")-Ia (aadA1) (33%), AAC(6′)-Ib (aacA4) (33%), ArmA (22%), and AAC(3)-IIa (aacC2) (19%). Among the 22 gene profiles detected in this study, the most prevalent profiles included APH(3′)-VIa + ANT(2")-Ia (39 isolates, 100% of which were kanamycin-resistant), and AAC(3)-IIa + AAC(6′)-Ib + ANT(3")-Ia + APH(3′)-VIa + ANT(2")-Ia (14 isolates, all of which were resistant to gentamicin, kanamycin, and streptomycin). CONCLUSIONS: High minimum inhibitory concentration of aminoglycosides in isolates with the simultaneous presence of AME- and ArmA-encoding genes indicated the importance of these genes in resistance to aminoglycosides. However, control of their spread could be effective in the treatment of infections caused by A. baumannii.

Investigation of carbapenemases and aminoglycoside modifying enzymes of Acinetobacter baumannii isolates recovered from patients admitted to intensive care units in a tertiary-care hospital in Brazil

Abstract INTRODUCTION: Acinetobacter baumannii are opportunistic bacteria, highly capable of acquiring antimicrobial resistance through the production of carbapenemases and aminoglycoside modifying enzymes (AMEs). METHODS: Carbapenemase and AME genes were investigated in A. baumannii recovered from inpatients of a Brazilian hospital. RESULTS: The key genes found were bla OXA-51-like, the association ISAba1- bla OXA-23-like, and the AME genes aph(3´)-VI, aac(6´)-Ib, aac(3)-Ia, and aph(3´)-Ia. Different clusters spread through the institution wards. CONCLUSIONS: The dissemination of bla OXA-23-like and AME-carrying A. baumannii through the hospital highlights the need for improved preventive measures to reduce the spread of infection.

Insuficiencia renal aguda en pacientes tratados con aminoglucósidos / Acute kidney injury in patients treated with aminoglycosides

Introducción: El riesgo de desarrollo de insuficiencia renal asociada al uso de aminoglucósidos es muchas veces una limitación para su uso en muchos profesionales de la salud. El objetivo de este trabajo fue conocer la frecuencia de insuficiencia renal en pacientes tratados con aminoglucósidos y los posibles factores asociados a su aparición. Materiales y métodos: Estudio descriptivo, longitudinal y prospectivo. Se incluyeron pacientes que recibieron aminoglucósidos por al menos 72 horas. Se realizó dosaje de creatinina basal y cada 48 horas durante el tratamiento antibiótico y luego de siete días de finalizado el mismo o posterior. Se definió insuficiencia renal aguda como el aumento de creatinina de 0,3 mg/dl con respecto a la basal. Resultados: Se analizaron datos de 107 pacientes y se halló una frecuencia de insuficiencia renal de 10,3%, siendo 5,8% durante el tratamiento aminoglucósido y 4,5% luego de la suspensión del mismo. Los pacientes que desarrollaron insuficiencia renal tenían mayores dosis de aminoglucósidos con respecto al grupo que no presentó dicho evento, siendo esta diferencia estadísticamente significativa. Conclusiones: La frecuencia de insuficiencia renal en pacientes tratados con aminoglucósidos resultó dentro de los intervalos descritos en la literatura y la mayoría de los pacientes presentaron recuperación completa de la función renal. Consideramos que la insuficiencia renal no supone un efecto adverso clínicamente significativo si los aminoglucósidos se usan con las precauciones adecuadas. Esto, sumado a sus buenos resultados clínicos y al bajo impacto en la ecología bacteriana, los convierte hoy en día en antibióticos de uso frecuente en nuestro hospital

The risk of developing renal failure associated with the use of aminoglycosides is often a limitation for its use in many health professionals. The objective of this study was to know the frequency of renal failure in patients treated with aminoglycosides and the possible factors associated with their appearance. Materials and methods: descriptive, longitudinal and prospective study. Patients who received aminoglycosides for at least 72 hours were included. Basal creatinine was measured and every 48 hours during the antibiotic treatment and after 7 days or more of its suspension. Acute renal failure was defined as an increase in creatinine of 0.3 mg/dl compared to baseline. Results: data from 107 patients were analyzed, and the frequency of renal failure was 10.3%, being 5.8% during the treatment with aminoglycoside and 4.5% after its suspension. The patients who developed renal failure had higher doses of aminoglycoside respect to the group that did not present this event, being this difference statistically significant. Conclusions: the frequency of renal failure in patients treated with aminoglycosides was within the ranges described in the literature and the majority of patients had complete recovery of renal function. We believe that renal failure does not represent a clinically significant adverse effect if aminoglycosides are used with adequate precautions. This, added to their good clinical results and low impact on bacterial ecology, makes them very used antibiotics today in our hospital

Caracterización clínico epidemiológica de los pacientes con infecciones por estafilococo dorado / Clinical-epidemiological characterization of patients with Staphylococcus aureus infections

RESUMEN Introducción: El estafilococo dorado es una causa importante de morbilidad y mortalidad en el mundo. En Cuba, es un germen a tener en cuenta como causa de infección intrahospitalaria. Objetivo: Caracterizar, clínica y epidemiológicamente, una muestra de pacientes con infecciones causadas por estafilococo dorado. Métodos: Se realizó un estudio observacional, descriptivo y transversal en el Hospital Militar "Dr. Mario Muñoz Monroy" de Matanzas, durante el período de enero a diciembre del año 2014. La población estuvo constituida por la totalidad de los pacientes hospitalizados con el diagnóstico de infección por estafilococo dorado (120 casos), identificados por el departamento de Microbiología; luego se revisaron las historias clínicas de las cuales se obtuvo la información. Resultados: Existió un predominio del sexo masculino (64,2 por ciento), los mayores de 60 años fueron los más afectados (36,7 por ciento). La diabetes mellitus fue la enfermedad asociada más frecuente (40,8 por ciento) y la mayoría de las infecciones fueron de origen comunitario (67,5 por ciento). Los aislamientos predominaron en las muestras tomadas de las lesiones en piel y los hemocultivos con un 50,8 por ciento y 19,2 por ciento, respectivamente. Se evidenció baja sensibilidad a la vancomicina (49,2 por ciento) y al cotrimoxazol (38,3 por ciento). Conclusiones: Las infecciones por estafilococo dorado fueron más frecuentes en pacientes masculinos geriátricos de su origen extrahospitalario. El germen presentó alta resistencia a los antibióticos y de estos, los aminoglucósidos mostraron la mayor sensibilidad antimicrobiana(AU)

Introduction: Staphylococcus aureus is an important cause of morbidity and mortality in the world. In Cuba, it is a germ to be taken into account as a cause of nosocomial infection. Objective: To characterize, clinically and epidemiologically, a sample of patients with infections caused by Staphylococcus aureus. Methods: An observational, descriptive and cross-sectional study was conducted at the Military Hospital "Dr. Mario Muñoz Monroy "of Matanzas, during the period from January to December of the year 2014. The population was constituted by all the patients hospitalized with the diagnosis of infection by Staphylococcus aureus (120 cases), identified by the department of Microbiology; then the medical records from which the information was obtained were reviewed. Results: There was a predominance of males (64.2 percent) those over 60 were the most affected (36.7 percent). Diabetes mellitus was the most frequent associated disease (40.8 percent) and the majority of infections were of community origin (67.5 percent). Positivity predominated in samples taken from skin lesions and blood cultures with 50.8 percent and 19.2 percent, respectively. Low sensitivity to vancomycin (49.2 percent) and cotrimoxazole (38.3 percent) was evidenced. Conclusions: Staphylococcus aureus infections were more frequent in geriatric male patients of out-of-hospital origin. The germ showed high resistance to antibiotics and of these, the aminoglycosides showed the highest antimicrobial sensitivity(AU)

Diversity of Genetic Environment of bla(CTX-M) Genes and Antimicrobial Susceptibility in Extended-spectrum β-lactamase producing Escherichia coli Isolated in Korea

Increasing resistance due to the production of extended-spectrum β-lactamase (ESBL) in Escherichia coli is a major problem to public health and CTX-M enzymes have become the most prevalent ESBL worldwide. In this study, resistance profiles of E. coli isolated in Korea and the genetic environments of bla(CTX-M) genes were analyzed by PCR and direct sequencing to clarify the mechanisms of spread of CTX-M. Resistance rates of CTX-M-producing E. coli, including β-lactams, fluoroquinolones and aminoglycosides, were significantly higher than that of CTX-M-non-producers (p<0.01). Of 41 tested, 39 (95.1%) isolates of CTX-M-producing E. coli showed resistance transfer by conjugation. All the transconjugants harboured large plasmids of 118~172 megadalton. Insertion sequence ISEcp1B was detected in the upstream of the bla(CTX-M) in 38 (92.7%) isolates with bla(CTX-M). ISEcp1B was disrupted by IS26 in 16 (39.0%) isolates with bla(CTX-M). ISEcp1B carried −35 and −10 promoter components between right inverted repeat (IRR) and the start codon of bla(CTX-M). orf477 or IS903D was observed in the downstream of the bla(CTX-M) in all the isolates with bla(CTX-M-3/15/55) or with bla(CTX-M-14/27), respectively. Sequence similar to IRR of ISEcp1B was located downstream of orf477. Target duplication sequences were detected both upstream of IRL and downstream of IRR. These results showed the involvement of ISEcp1B in the mobilization of the resistance genes. In conclusion, the surrounding DNAs of bla(CTX-M) genes were very diverse, and the spread and the expression of CTX-M may be deeply related with ISEcp1B. These informations will provide important knowledge to control the increase in CTX-M-ESBLs.

Prevalence and molecular characteristics of 16s rRNA methylase gene rmtB in amikacin resistant Escherichia coli isolated from South Korea / 대한수의학회지

The production of rmtB-encoded 16S rRNA methylases has emerged as a novel mechanism promoting high-level resistance toward aminoglycosides in Gram-negative bacteria. Between 2015 and 2017, 636 distinct commensal Escherichia (E.) coli isolates were collected from different farms in South Korea to determine the prevalence and molecular characteristics of rmtB. The positive rates of rmtB between all the isolates and amikacin-resistant isolates were 1.1 and 100%, respectively. High-level aminoglycoside resistance could be transferred by conjugation from rmtB-positive donors to higher amikacin-resistance efficacies. This is the first report of 16S rRNA methylase-encoding genes in E. coli isolated from food-producing animals in Korea.

Emergence of aph(3')-VI and accumulation of aminoglycoside modifying enzyme genes in KPC-2-possessing Enterobacter aerogenes isolates from infections and colonization in patients from Recife-PE, Brazil

Abstract INTRODUCTION: The objective of this study was to characterize genes of aminoglycoside modifying enzymes (AMEs) in colonizing and infecting isolates of E. aerogenes harboring bla KPC from patients at a public hospital in Recife-PE, Brazil. METHODS: We analyzed 29 E. aerogenes clinical isolates resistant to aminoglycosides. AMEs genes were investigated by PCR and sequencing. RESULTS: Colonizing and infecting isolates mainly presented the genetic profiles aac(3)-IIa/aph(3')-VI or ant(2")-IIa/aph(3')-VI. This is the first report of aph(3')-VI in E. aerogenes harboring bla KPC in Brazil. CONCLUSIONS: The results highlight the importance in establishing rigorous methods for the surveillance of resistance genes, especially in colonized patients.

Genotypic characterization of aminoglycoside resistance genes from bacteria isolates in selected municipal drinking water distribution sources in Southwestern Nigeria

BACKGROUND: Multi-drug Resistant (MDR) bacteria could lead to treatment failure of infectious diseases and could be transferred by non-potable water. Few studies have investigated occurrence of Antibiotic Resistance Genes (ARGs) among bacteria including Aminoglycoside Modifying Genes (AMGs) from Drinking Water Distribution Systems (DWDS) in Nigeria. Here, we aimed at characterization of AMGs from DWDS from selected states in southwestern Nigeria. METHODS: One hundred and eighty one (181) MDR bacteria that had been previously characterized using 16S rDNA and showed resistance to at least one aminoglycoside antibiotic were selected from treated and untreated six water distribution systems in southwestern Nigeria. MDR bacteria were PCR genotyped for three AMGs:aph (3´´)c, ant (3´´)b and aph(6)-1dd. RESULTS: Out of 181 MDR bacteria genotyped, 69(38.12%) tested positive for at least one of the genotyped AMGs. Highest (50, 27.62%) detected gene was ant (3")c followed by aph (3")c(33,18.23%). Combination of aph(3")c and ant (3")b in a single bacteria was observed as the highest (14, 7.73%) among the detected gene combination. Alcaligenes sp showed the highest (10/20) occurrence of ant (3")b while aph(3")c was the highest detected among Proteussp (11/22). Other bacteria that showed the presence of AMGs include: Acinetobacter, Aeromonas, Bordetella, Brevundimonas, Chromobacterium, Klebsiella, Leucobacter, Morganella, Pantoae, Proteus, Providencia, Psychrobacter and Serratia. CONCLUSIONS: High occurrence of ant (3")c and aph (3")c among these bacteria call for urgent attention among public health workers, because these genes can be easily disseminated to consumers of these water samples if present on mobile genetic elements like plasmids, integrons and transposons

Analysis of Integrons and Antimicrobial Resistances of Multidrug Resistant Escherichia coli Isolated in Korea

Antibacterial drugs are one of the most important therapeutic agents of bacterial infections but multidrug resistant Escherichia coli (MDREC) is an increasing problem worldwide. Major resistance mechanism of MDREC is horizontal gene transfer of R plasmids harboring integrons, which the integron integrase (IntI) catalyzes gene cassette insertion and excision through site specific recombination. In this study, resistance profiles of integron harboring E. coli isolated in Korea and the genetic environments of integron gene cassettes were analyzed by PCR and direct sequencing to clarify the mechanisms of spread of integron harboring E. coli. Resistance rates of integron harboring E. coli, including β-lactams, aminoglycosides, and fluoroquinolones and MDR frequencies were significantly higher than that of E. coli without integron (p < 0.01). Majority (80%) of integron harboring E. coli showed resistance transfer by conjugation. Most (80%) of E. coli had dfrA17-aadA5 cassette array and PcH1 hybrid promoter; 16.7% of E. coli had dfrA12-orfF-aadA2 cassette array and PcW promoter. The higher prevalence of weak Pc variants among most (96.7%) of integron harboring MDREC suggests that a flexible cassette array is more important than enhanced expression. All the integrons had LexA binding motif suggests that SOS responses control the expression of these integrons. In conclusion, the genetic bases of integrons were diverse, and the spread and the expression of prevalent gene cassette arrays may be deeply related with strengths of Pc promoters in integrons. These informations will provide important knowledge to control the increase of integron harboring MDREC.

Effect of polymyxin B-containing regimens on renal function for the treatment of carbapenem-resistant Enterobacteriacea mediastinitis

ABSTRACT A retrospective cohort study, were evaluated: polymyxin B plus aminoglycosides or polymyxin B plus other antibiotics. Any degree of acute kidney injury occurred in 26 (86.6%) patients. The median time to acute kidney injury was 6.0 (95% CI 3-14) days in the polymyxin-aminoglycoside containing regimen group, against 27.0 (95% CI 6-42) days in the polymyxin with other antimicrobial combinations group (p = 0.03). Polymyxin B with aminoglycosides group progressed faster to any degree of renal dysfunction.

Carbapenem-resistant Enterobacteriaceae: recent updates and treatment strategies

The emergence of carbapenem-resistant Enterobacteriaceae (CRE) has become a major problem within the field of healthcare-associated infections worldwide in the last decade. The treatment of infections caused by CRE is challenging, and a consensus strategy has not been established. This article reviews old and new antibiotics for the treatment of CRE, and summarizes the overall mechanisms of resistance, epidemiology, diagnosis, and infection control of CRE. For CRE treatment, combination therapies may be preferred. Carbapenem still plays an important role in CRE treatment. Other existing treatment options against CRE include colistin, tigecycline, fosfomycin, and aminoglycosides. New therapeutic options include ceftazidime-avibactam, aztreonam-avibactam, plazomicin, eravacycline, meropenem-vaborbactam, and imipenem-cilastatin-relebactam. Few randomized controlled trials have been conducted, so more studies of new agents against CRE are needed. Because there are relatively few therapeutic options for CRE, adequate infection prevention measures and antimicrobial stewardship are required. Moreover, both personal and national preventive efforts are needed.

Prevalence of Fecal Carriage of CTX-M-15 Beta-Lactamase-Producing Escherichia coli in Healthy Children from a Rural Andean Village in Venezuela

OBJECTIVES: Antimicrobial resistant extended-spectrum-β-lactamase-producing Enterobacteriaceae (ESBL-PE) have been shown to be present in healthy communities. This study examined healthy children from the rural Andean village of Llano del Hato, Mérida, Venezuela, who have had little or no antibiotic exposure to determine the prevalence of fecal carriage of ESBL-producing Escherichia coli (ESBL-EC). METHODS: A total of 78 fecal samples were collected in healthy children aged from 1 to 5 years. ESBL-EC were selected in MacConkey agar plates with cefotaxime and further confirmed by the VITEK 2 system. ESBL were phenotypically detected and presence of bla genes and their variants were confirmed by molecular assays. Determination of phylogenetic groups was performed by PCR amplification. Risk factors associated with fecal carriage of ESBL-EC-positive isolates were analyzed using standard statistical methods. RESULTS: Of the 78 children studied, 27 (34.6%) carried ESBL-EC. All strains harbored the bla(CTX-M-15) allele. Of these, 8 were co-producers of bla(TEM-1), bla(TEM-5), bla(SHV-5) or bla(SHV-12). Co-resistance to aminoglycosides and/or fluoroquinolones was observed in 9 strains. 51.9% of ESBL-EC isolates were classified within phylogroup A. A significant, positive correlation was found between age (≥2.5 – ≤5 years), food consumption patterns and ESBL-EC fecal carriage. CONCLUSION: This is the first study describing the high prevalence of fecal carriage of ESBL-EC expressing CTX-M-15- among very young, healthy children from a rural Andean village in Venezuela with scarce antibiotic exposure, underlining the importance of this population as a reservoir.

Antimicrobial Therapy for Infections Caused by Carbapenem-Resistant Gram-Negative Bacteria / 대한내과학회지

Carbapenem-resistance emerging in Gram-negative pathogens, such as Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii, has become a major human health problem globally. The therapeutic options available for carbapenem-resistant pathogens are very limited. Antibiotics such as colistin, tigecycline, fosfomycin, and aminoglycosides are often the only ones that can be used to treat carbapenem-resistant pathogens. Carbapenem may still be an option in certain circumstances. The administration of combination therapy for carbapenem-resistant pathogens is controversial. This review presents the current knowledge of available antimicrobial therapeutic options for infections due to carbapenem-resistant pathogens in Korea.