Síndrome de compresión medular de etiología infecciosa

El síndrome de compresión medular es una urgencia neuroquirúrgica debido a que un diagnóstico precoz y un tratamiento temprano podría revertir las incapacitantes secuelas ocasionadas por esta enfermedad. Las causas de este síndrome pueden ser traumática, metastásica, infecciosa y vascular (hematomas). La etiología infecciosa no es frecuente y el principal germen involucrado suele ser Staphylococcus aureus. A continuación presentamos el caso de una paciente de 58 años con síndrome de compresión medular de etiología infecciosa quien fue ingresada en el Servicio de Clínica Médica del Centro Médico Nacional.

Spinal cord compression syndrome is a neurosurgical emergency because early diagnosis and early treatment could reverse the disabling consequences caused by this disease. The causes of this syndrome can be traumatic, metastatic, infectious, and vascular (hematomas). Infectious etiology is not frequent and the main germ involved is usually Staphylococcus aureus. Below we present the case of a 58-year-old patient with spinal cord compression syndrome of infectious etiology who was admitted to the Medical Clinic Service of the National Medical Center.

Piomiositis en pediatría: experiencia de 10 años en un hospital pediátrico de alta complejidad en Argentina

Introducción: La piomiositis es una infección bacteriana agudasubaguda del músculo esquelético. Objetivo: Estimar la incidencia de piomiositis en pacientes internados, describir e identificar factores de riesgo para bacteriemia y hospitalización, y evaluar diferencias entre Staphylococccus aureus sensible y resistente a meticilina (SASM y SARM). Pacientes y Métodos: Estudio descriptivo, retrospectivo, observacional, con pacientes de 1 mes a 18 años de edad, internados entre el 1 de enero de 2008 y 31 de diciembre de 2018. Variables: sexo, edad, hacinamiento en el hogar, existencia de lesión previa, estacionalidad, localización anatómica e imágenes, antibioterapia previa, estadio clínico, parámetros de laboratorio, cultivos y antibiograma, días de tratamiento intravenoso (IV), de internación, de fiebre y bacteriemia. Resultados: Se incluyeron 188 pacientes. Incidencia: 38,9 casos / 10.000 admisiones (IC95 % 33,7 - 44,9). Días de internación y tratamiento IV: 11 (RQ 8-15 y RQ 8-14, respectivamente). El desarrollo de bacteriemia se asoció a PCR elevada (p = 0,03) y fiebre prolongada (p < 0,001). No hubo diferencias en la evolución y parámetros de laboratorio entre SASM y SARM. La leucocitosis (p = 0,004), neutrofilia (p = 0,005) y bacteriemia (p = 0,001) se asociaron a mayor estadía hospitalaria. Conclusiones: Este estudio recaba la experiencia de más de 10 años de niños internados con diagnóstico de piomiositis y proporciona información sobre sus características. Se describen parámetros asociados a bacteriemia y estadía hospitalaria.

Background: Pyomyositis is an acute-subacute bacterial infection of skeletal muscle. Aim: To estimate the incidence of pyomyositis in hospitalized patients, describe and identify risk factors for bacteremia and hospitalization, and evaluate differences between MSSA and MRSA. Methods: Descriptive, retrospective, observational study with patients aged 1 month to 18 years hospitalized between January, 1, 2008 and December 1, 2018. Variables: sex, age, home overcrowding, previous injury, seasonality, anatomical location and images, previous antibiotherapy, clinical stage, laboratory, cultures and antibiogram, days of intravenous (IV) treatment, hospitalization, fever and bacteremia. Results: 188 patients were included. Incidence: 38.9 cases/10,000 admissions (95% CI 33.7 - 44.9). Days of hospitalization and IV treatment: 11 (RQ 8-15 and RQ 8-14, respectively). The development of bacteremia was associated with elevated CRP (p = 0.03) and prolonged fever (p < 0.001). There were no differences in the evolution and laboratory parameters between MSSA and MRSA. Leukocytosis (p = 0.004), neutrophilia (p = 0.005), and bacteremia (p = 0.001) were associated with a longer hospital stay. Conclusions: This study collects the experience of more than 10 years of hospitalized children diagnosed with pyomyositis and provides information on its characteristics. Parameters associated with bacteremia and hospital stay are described.

Molecular epidemiology progress of community-associated Methicillin-resistant Staphylococcus aureus infection in children / 中华实用儿科临床杂志

Antimicrobial resistance of Staphylococcus aureus is a main factor for the poor prognosis.In China, the detection rate of Methicillin-resistant Staphylococcus aureus (MRSA) in children is annually increasing, especially the community-acquired MRSA (CA-MRSA). This review discussed molecular characteristics, antimicrobial resistance mechanism and antimicrobial resistance progress of CA-MRSA, and analyzed recent molecular epidemiology and changes of drug resistance to CA-MRSA in children from China, thus providing theoretical basis for the prevention and control of CA-MRSA in children.

Frecuencia del gen mecA en Staphylococcus aureus meticilinorresistente en un hospital de tercer nivel en Perú

Objetivos: determinar la frecuencia del gen mecA en Staphylococcus aureus resistente a meticilina (MRSA) aislados de pacientes atendidos en un hospital de tercer nivel en la región Cajamarca, Perú; asimismo, determinar cuál de los dos antibióticos usados como screening fenotípico tiene mayor utilidad para explicar la presencia de dicho gen. Métodos: se analizaron 71 aislamientos bacterianos provenientes de muestras del Hospital Regional Docente de Cajamarca, la identificación de S. aureus se llevó a cabo mediante el equipo MicroScan. El screening fenotípico para resistencia a meticilina se realizó mediante la técnica de difusión, con discos de cefoxitina y oxacilina. La extracción de ADN se realizó mediante shock térmico, la detección del gen mecA se realizó mediante reacción en cadena de la polimerasa. El análisis estadístico se realizó con el software SPSS v.25. Resultados: de los 71 aislados, 40 (56,3%) fueron MRSA portadores del gen mecA, la mayoría de estos aislamientos correspondieron a pacientes hospitalizados 22 (31,0%), siendo más frecuentes en muestras de secreción bronquial 27 (38,0%). El screening fenotípico con disco de cefoxitina predijo mejor la presencia del gen mecA [P=0,010; Exp(B)= 12,3] en comparación con el disco de oxacilina. Conclusiones: este estudio demostró alta frecuencia de MRSA mecA positivo en muestras de origen clínico, principalmente de pacientes hospitalizados. Es importante establecer medidas de vigilancia para identificar MRSA en todos los hospitales de la región.

Objective: to determine the frequency of the mecA gene in methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients treated at a third-level hospital in the Cajamarca region, Peru; as well as, to determine which of the two antibiotics used as phenotypic screening is more useful in explaining the presence of said gene. Methods: 71 bacterial isolates were analyzed from samples obtained from the Hospital Regional Docente of Cajamarca. The identification of S. aureus was carried out using the MicroScan system. Phenotypic screening for resistance to methicillin was performed using the diffusion technique with cefoxitin and oxacillin discs. DNA extraction was performed by heat shock, mecA gene detection was performed through polymerase chain reaction. For data analysis, the statistical software SPSS v.25 was used. Results: from 71 isolates, 40 (56,3%) were MRSA carriers of the mecA gene, the majority of these isolates corresponded to hospitalized patients 22 (31,0%), being more frequent in bronchial secretion samples 27 (38,0%). Phenotypic screening with cefoxitin disc was a better predictor for the presence of the mecA gene [P=0,010; Exp(B)= 12,3] compared to the oxacillin disc. Conclusions: It is shown a high frequency of positive MRSA mecA in samples of clinical origin, mainly from hospitalized patients. It is important to establish surveillance guidelines to identify MRSA in all hospitals in the region.

In vitro efficacy and combined drug sensitivity of lycosin-I against methicillin-resistant Staphylococcus aureus / 中华检验医学杂志

Objective:The aim of this study was to evaluate the in vitro activity of lysosin-Ⅰ against Methicillin-resistant Staphylococcus aureus (MRSA) and its synergistic effect with eight common antibacterial drugs against MRSA. Methods:This study was conducted following the design principles of a randomized controlled trials. Ten MRSA isolates, clinically isolated from the Second Xiangya Hospital of Central South University between September and November 2021, were determined the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetic test of lycosin-Ⅰ in vitro anti-MRSA by micro-broth dilution method. Additionally, the micro-broth chessboard dilution method was utilized to evaluate the in vitro efficacy of lycosin-Ⅰ in combination with eight common antimicrobial agants, including penicillin, erythromycin, levofloxacin, gentamicin, rifampicin, minocycline, vancomycin, and linezolid. Results:The MIC range of lycosin-Ⅰ against MRSA was found to be between 4-8 mg/L with the MIC 50 and MIC 90 were 4 mg/L and 8 mg/L, respectively. The range of MBC was also between 4-8 mg/L, and the ratio of MBC/MIC was 1-2. The bactericidal kinetics test revealed that the number of surviving MRSA clinical isolates and standard strains initially decreased rapidly but then showed a resurgence when the concentration of lycosin-Ⅰ was 1/2 MIC or MIC. While, the bacterial load gradually reduced until complete elimination when the concentration was at 2 MIC or 4 MIC. The combination of lycosin-Ⅰ and gentamicin exhibited mainly synergistic effects, while the combination with other antibiotics showed mainly additive effects. Moreover, the combination of lycosin-Ⅰ and antibacterial drugs can significantly reduce the MIC 50 and MIC 90 of antibiotics. Conclusion:lycosin-Ⅰ has great antibacterial and bactericidal activity against MRSA in vitro with rapid and thorough sterilization effect and it can play a synergistic or additive role when combined with other antibacterial drugs against MRSA in vitro.

Feasibility study on rapid identification of methicillin-resistant Staphylococcus aureus by different algorithms of MALDI-TOF mass spectrometry / 中华检验医学杂志

Objective:To explore the feasibility of rapid identification of methicillin-resistant Staphylococcus aureus using different algorithms of the matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometer. Methods:Totally 314 clinical isolates of Staphylococcus aureus were selected from the bacterial bank at Beijing Tongren Hospital from January 2017 to June 2019. The samples were identified by MALDI-TOF MS, and screened by cefoxitin disk method (inhibition ring diameter ￡21 mm) and PCR mecA gene. The strains were divided into a methicillin-resistant Staphylococcus aureus (MRSA) group (130 strains) and a methicillin-susceptible Staphylococcus aureus (MSSA) group (184 strains). Then, after collecting the spectrograms of these samples using formic acid extraction, the MRSA group and MSSA group were divided into three subgroups each, namely MRSA-1 (43 strains), MRSA-2 (42 strains), MRSA-3 (45 strains) and MSSA-1 (60 strains), MSSA-2 (61 strains) and MSSA-3 (63 strains). The groups were studied using genetic algorithm (GA), fast classification algorithm (QC) and supervised neural network algorithm (SNN) in the ClinProTools software on the Bruker MALDI-TOF mass spectrometer, and the convolutional neural network algorithm (CNN) in the Ex-SmartSpec software on the Zhongyuan Hui-Ji mass spectrometer. These studies were repeated for 3 rounds. The first round with MRSA-1 and MRSA-2, MSSA-1 and MSSA-2 being model groups, MRSA-3 and MSSA-3 being validation groups. The validation groups were rotated for each round. The areas under the receiver operating characteristic (ROC) curve expansions of the four algorithms were used to confirm each program′s performance. Then, 38 MRSA strains and 40 MSSA clinical strains were selected from the bacterial bank of the Laboratory of Beijing Tongren Hospital from July 2019 to December 2019, and were put through the formic acid extraction method to collect their spectra. These samples were tested independently with their convolutional neural network models. Results:After three rounds of modeling and verification, the areas under the ROC curves of the three Bruker ClinProTools programs were as follows: for genetic algorithm, the areas were 0.89, 0.74, and 0.64 respectively; for fast classification algorithm, the areas were 0.77, 0.95, and 0.94 respectively; and for supervised neural network algorithm, the areas were 0.90, 0.98, and 0.98 respectively. The areas under the ROC curves of the convolutional neural network algorithm with Zhongyuan Huiji mass spectrometer′s Ex-SmartSpec software were 0.95, 0.99, and 0.99 respectively. The independent test results of convolutional neural network algorithm showed that these results have an accuracy, specificity, sensitivity and AUC of 88.82% (810/912), 81.15% (779/960), 84.88% (1 589/1 872) and 0.92 respectively.Conclusions:The supervised neural network algorithm of Bruker′s ClinProTools and the convolutional neural network algorithm of Zhongyuan Hui-Ji mass spectrometer′s EX-Smartspec is clinically acceptable for rapid identification of MRSA performance indicators. Using convolutional neural network algorithm and MALDI-TOF mass spectrometry, MRSA strains can be identified quickly, providing timely advice for clinical medications.

Memantine hydrochloride promotes the antibacterial effect of neutrophils against methicillin-resistant Staphylococcus aureus and the related mechanism / 中华微生物学和免疫学杂志

Objective:To investigate whether memantine hydrochloride (MEM) could promote the bactericidal effect of neutrophils against methicillin-resistant Staphylococcus aureus (MRSA) and the possible mechanism. Methods:Neutrophils were co-incubated with different concentrations of MEM and MRSA for 4 h. Then the cell lysates were collected and cultured on plate for survival bacteria counting. After co-incubation, the neutrophils were collected to detect the production of reactive oxygen species (ROS) and the release of neutrophil extracellular traps (NETs). A mouse model of MRSA infection was established, and then the mice were treated with or without MEM. Blood, spleen and kidney samples were collected from the mice for bacterial colony counting and blood procalcitonin (PCT) detection. In the 48 h survival experiment, the mice were first infected with MRSA, and then treated with MEM or PBS. The survival rates of the mice were calculated and the survival curves were drawn.Results:The number of MRSA co-cultured with neutrophils decreased significantly in the presence of MEM, and within a certain concentration range, the survival number of MRSA decreased with the increase of MEM concentration. Moreover, MEM could significantly promote the production of ROS by neutrophils and the formation of NETs. In vivo experiment showed that the concentration of PCT in mouse blood samples was lower in the MRSA+ MEM group than in the MRSA+ PBS group. The animal experiment also revealed that MEM significantly decreased the bacteria loads in mouse blood and organs and increased the 48 h survival rate after MRSA infection.Conclusions:MEM could significantly promote the bactericidal effect of neutrophils against MRSA, which might be related to the enhanced generation of ROS by neutrophils and the formation of NETs.

Tratamiento de las infecciones hospitalarias por staphylococcus aureus meticilino resistente / Treatment of hospital-acquired methicillin-resistant staphylococcus aureus infections / Tratamento de infecções por Staphylococcus aureus resistentes à meticilina, adquiridas em hospitais

Introducción: la infección por Staphylococcus aureus meticilino resistente, una de las principales bacterias causantes de infecciones hospitalarias, se ha convertido en una preocupación mundial dada la alta tasa de morbilidad y mortalidad que produce. La resistencia bacteriana es un factor que agrava la problemática de infecciones hospitalarias y se asocia fundamentalmente al uso inadecuado de antibióticos. El uso prudente de los mismos ayuda a controlar la resistencia bacteriana, sin embargo, cada vez se detectan más cepas resistentes a diversos antibióticos. Se realiza una revisión de tratamientos antibióticos disponibles para las infecciones hospitalarias producidas por Staphylococcus aureus meticilino resistente en paciente adulto, con la finalidad de proporcionar una guía sobre los mismos, que permita un uso racional de los antibióticos disponibles evitando así que se continúe desarrollando el fenómeno de resistencia bacteriana. Metodología: se realizó un estudio observacional, descriptivo, de tipo revisión literaria, restringiéndose la búsqueda a guías de práctica clínica. Para conocer las guías existentes en Uruguay se consultó la Cátedra de Enfermedades Infecciosas de la Facultad de Medicina, Universidad de la República y en el Ministerio de Salud Pública. Se encontraron y analizaron guías de diferentes países. Existe acuerdo en los lineamientos generales del tratamiento farmacológico de las infecciones hospitalarias por Staphylococcus aureus meticilino resistente. Resultados: en Uruguay no existen guías propias de tratamiento de las infecciones hospitalarias por Staphylococcus aureus meticilino resistente. Se utiliza como referencia la guía publicada por la Infectious Diseases Society of America. Discusión: algunos de los antibióticos recomendados en las guías analizadas no se encuentran disponibles en nuestro país, como es el caso de daptomicina, telavancina y cloxacilina. En particular, el no disponer de daptomicina podría llegar a dificultar el tratamiento de infecciones en las cuales la CIM de vancomicina sea mayor a 1.5 mg/L. Conclusiones: por lo tanto, se considera conveniente y necesario pautar el tratamiento de dichas infecciones, acorde a las posibilidades, a la epidemiología de nuestro país y a los patrones de resistencia a ésta bacteria, para unificar la práctica clínica y hacer un uso racional de los antibióticos de manera de evitar promover el fenómeno de resistencia microbiana.

Introduction: infection by methicillin-resistant Staphylococcus aureus, one of the main bacteria causing hospital infections, has become a worldwide concern due to the high morbidity and mortality rate it produces. Bacterial resistance is a factor that aggravates the problem of hospital infections and is mainly associated with the inappropriate use of antibiotics. The prudent use of antibiotics helps to control bacterial resistance; however, more and more strains resistant to different antibiotics are being detected. A review of available antibiotic treatments for hospital infections caused by methicillin-resistant Staphylococcus aureus in adult patients was carried out in order to provide a guide for a rational use of available antibiotics, thus avoiding further development of the phenomenon of bacterial resistance. Methodology: an observational, descriptive, literature review type study was carried out, restricting the search to clinical practice guidelines. In order to know the existing guidelines in Uruguay, the Department of Infectious Diseases of the School of Medicine, University of the Republic and the Ministry of Public Health were consulted. Guidelines from different countries were found and analyzed. There is agreement on the general guidelines for pharmacological treatment of hospital infections caused by methicillin-resistant Staphylococcus aureus. Results: in Uruguay there are no guidelines for the treatment of hospital infections caused by methicillin-resistant Staphylococcus aureus. The guidelines published by the Infectious Diseases Society of America are used as a reference. Discussion: some of the antibiotics recommended in the guidelines analyzed are not available in our country, as is the case of daptomycin, telavancin and cloxacillin. In particular, the unavailability of daptomycin could make the treatment of infections in which the MIC of vancomycin is higher than 1.5 mg/L more difficult. Conclusions: therefore, it is considered convenient and necessary to establish guidelines for the treatment of such infections, according to the possibilities, to the epidemiology of our country and to the resistance patterns to this bacterium, in order to unify clinical practice and make a rational use of antibiotics so as to avoid promoting the phenomenon of microbial resistance.

Introdução: a infecção por Staphylococcus aureus resistente à meticilina, uma das principais bactérias causadoras de infecções hospitalares, tornou-se uma preocupação mundial devido à alta taxa de morbidade e mortalidade que ela causa. A resistência bacteriana é um fator que agrava o problema das infecções adquiridas nos hospitais e está principalmente associada ao uso inadequado de antibióticos. O uso prudente de antibióticos ajuda a controlar a resistência bacteriana, entretanto, cada vez mais estirpes resistentes a vários antibióticos estão sendo detectadas. É realizada uma revisão dos tratamentos antibióticos disponíveis para infecções hospitalares causadas por Staphylococcus aureus resistente à meticilina em pacientes adultos, com o objetivo de fornecer um guia para o uso racional dos antibióticos disponíveis, evitando assim o desenvolvimento posterior do fenômeno de resistência bacteriana. Metodologia: foi realizado um estudo observacional, descritivo, do tipo revisão de literatura, restringindo a busca às diretrizes da prática clínica. O Departamento de Doenças Infecciosas da Faculdade de Medicina da Universidade da República e o Ministério da Saúde Pública foram consultados para as diretrizes existentes no Uruguai. Foram encontradas e analisadas diretrizes de diferentes países. Há acordo sobre as diretrizes gerais para o tratamento farmacológico de infecções hospitalares causadas por Staphylococcus aureus resistente à meticilina. Resultados: no Uruguai não há diretrizes para o tratamento de infecções por Staphylococcus aureus resistentes à meticilina adquiridas em hospitais. As diretrizes publicadas pela Sociedade de Doenças Infecciosas da América são usadas como referência. Discussão: alguns dos antibióticos recomendados nas diretrizes analisadas não estão disponíveis na Espanha, tais como daptomicina, telavancina e cloxacilina. Em particular, a indisponibilidade da daptomicina poderia dificultar o tratamento de infecções nas quais a MIC da vancomicina é maior que 1,5 mg/L. Conclusões: portanto, considera-se conveniente e necessário estabelecer diretrizes de tratamento para estas infecções, de acordo com as possibilidades, a epidemiologia de nosso país e os padrões de resistência a esta bactéria, a fim de unificar a prática clínica e fazer uso racional dos antibióticos, a fim de evitar a promoção do fenômeno da resistência microbiana.

Characterization and antimicrobial susceptibility of coagulase-positive Staphylococcus isolated in a veterinary teaching hospital in Chile / Caracterización y sensibilidad antimicrobiana de Staphylococcus coagulasa-positivos aislados en un hospital clínico veterinario en Chile

Abstract There is limited information about the prevalence and antimicrobial susceptibility of coagulase-positive Staphylococcus (CoPS) strains in veterinary settings in Chile. The aim of this observational study was to identify and characterize CoPS strains from dogs, owners, veterinary professionals and surfaces in a veterinary teaching hospital at Universidad de Chile to determine the presence of methicillin-resistant strains and evaluate the genetic relationship among the strains. Veterinarians (n = 24), surfaces (n = 10), and healthy dogs (n = 40) and their respective owners (n = 40) were sampled for CoPS. Isolates were identified by PCRand antimicrobial susceptibility was assessed by the disk diffusion method and MIC. The presence of the mecA gene was evaluated by PCR, and the genetic relationship among the strains was established by PFGE. A total of 45 CoPS strains were obtained, eight from veterinary professionals, three from hospital surfaces, eight from owners and 26 from dogs. Nine of the strains were resistant to methicillin (20%), and all of them carried the mecA gene. A high percentage of the strains was resistant to clindamycin (33.3%). Additionally, the isolated CoPS showed high genetic diversity. This study suggests that veterinarians are in high risk of harboring methicillin-resistant CoPS (25% versus 2.5% from owners) and our results provide evidence that clindamycin could not be an empiric alternative for CoPS in the analyzed hospital. This is the first report of methicillin-resistant CoPS in veterinary settings in Chile, considering humans, pets and surfaces.

Resumen Existe información limitada sobre prevalencia y sensibilidad antimicrobiana de cepas de Staphylococcus coagulasa-positivas (CoPS) en entornos veterinarios en Chile. El objetivo de este estudio observacional fue identificar y caracterizar cepas CoPS de perros, duenos, veterinarios y superficies de un hospital veterinario de la Universidad de Chile, determinar la presencia de cepas meticilino-resistentes y evaluar la relación genética entre las cepas. Se colectaron muestras de veterinarios (n = 24), de superficies hospitalarias (n = 10) y de perros sanos (n =40) y sus respectivos duenos (n = 40). Los aislamientos se identificaron mediante PCR y la sensibilidad antimicrobiana se evaluó por difusión en discos y CIM. También se empleó PCR para detectar la presencia del gen mecA; la relación genética entre las cepas se estableció mediante electroforesis de campos pulsantes (PFGE). Se obtuvo un total de 45 cepas de CoPS, 8 de veterinarios, 3 de superficies hospitalarias, 8 de duenos y 26 de perros. Nueve cepas fueron meticilino-resistentes (20%), todas portadoras del gen mecA. Un porcentaje importante de cepas fue resistente a clindamicina (33,3%). Además, las cepas aisladas mostraron una alta diversidad genética. Este estudio sugiere que los veterinarios tienen alto riesgo de portar CoPS resistentes a meticilina (25% versus 2,5% propietarios). Asimismo, nuestros resultados proporcionan evidencia de que la clindamicina podría no ser una alternativa empírica para CoPS en el hospital analizado. Este es el primer estudio de CoPS meticilino-resistentes en entornos veterinarios en Chile que considera humanos, mascotas y superficies.

Virulence, biofilm formation ability and antimicrobial resistance of staphylococcus aureus isolated from cell phones of university students / Virulência, capacidade de formação de biofilme e resistência antimicrobiana de staphylococcus aureus isolado de telefones celulares de estudantes universitários

INTRODUCTION: Contamination of cell phones can contribute to the dissemination of pathogens in the community and/or hospital environment. OBJECTIVE: To characterize Staphylococcus aureus strains isolated from cell phones of university students. METHODS: Samples were collected from 100 cell phones. Detection of genes associated with virulence factors such as biofilm formation (icaA and icaD), enterotoxins production (SEA, SEB, SEC, and SED), and resistance to methicillin (mecA and mecC) was performed in S. aureus isolates by PCR. Typing mecA gene performed by multiplex PCR. Susceptibility to antimicrobials and biofilm formation rate also evaluated by using disk diffusion test and crystal violet staining. RESULTS: S. aureus was present in 40% of the total samples and about 70% of them belonged to Nursing students. Of the isolates, 85% presented resistance to penicillin and 50% were classified as moderate biofilm producers. In addition, 92.5% of isolates contained the gene icaA and 60% of the gene icaD. Approximately 25% of the isolates presented the mecA gene. Typing of the mecA gene showed the presence of staphylococcal chromosome cassette SCCmec I and c III respectively in 20% and 10% of the isolates. 70% of the samples could not be typed by the technique. Regarding the enterotoxins, the most prevalent gene was SEA (30%) followed by the SEC gene (2.5%). The presence of SED and SEB genes not observed in any of the isolates. CONCLUSION: The cleaning and periodic disinfection of cell phones can contribute to the reduction of the risk of nosocomial infection.

INTRODUÇÃO: A contaminação de celulares pode contribuir para a disseminação de patógenos na comunidade e/ou ambiente hospitalar. OBJETIVO: Caracterizar cepas de Staphylococcus aureus de telefones celulares de estudantes universitários. MÉTODOS: Foram coletadas amostras de 100 telefones celulares. Detecção de genes associados a fatores de virulência quanto a: formação de biofilme (icaA e icaD), produção de enterotoxinas (SEA, SEB, SEC e SED) e resistência à meticilina (mecA e mecC) foi realizada em isolados de S. aureus por PCR. A Tipagem do gene mecA foi realizada por PCR multiplex. A susceptibilidade a antimicrobianos e a taxa de formação de biofilme pelo teste de difusão em disco e coloração com cristal violeta. RESULTADOS: S. aureus esteve presente em 40% do total de amostras, destas, 70% pertenciam a estudantes do curso de enfermagem. Dos isolados, 85% apresentaram resistência à penicilina e 50% foram classificados com moderada formação de biofilme. Além disso, 92,5% dos isolados continham o gene icaA e 60% o gene icaD. Aproximadamente 25% dos isolados apresentaram o gene mecA. A tipagem do gene mecA mostrou a presença do cassete cromossômico estafilocócico SSCmec I e III em respectivamente 20% e 10% dos isolados. 70% das amostras não puderam ser identificadas pela técnica. Das enterotoxinas, o gene mais prevalente foi o SEA (30%), seguido pelo gene SEC (2.5%). A presença dos genes SED e SEB não foi observada nos isolados. CONCLUSÃO: A limpeza e desinfecção periódica dos telefones celulares podem contribuir para a redução do risco de infecção nosocomiais.

Methicillin resistant Staphylococcus aureus-importance of appropriate empirical therapy in serious infections

India has been titled the capital of antimicrobial resistance in the world with the centre for disease dynamics, economics andpolicy (CDDEP) predicting two million deaths in India by 2050. As per the World Health Organisation抯 global priority pathogen list of 2017, methicillin resistant Staphylococcus aureus(MRSA)has been classified as a 慼igh priority� pathogen due to its association with increased mortality rate, rising prevalence of resistance and increased burden on healthcare settings. A recent report by Indian Council of Medical Research signifies the exponential rise in the prevalence of MRSA in India, from 29% in 2009 to 39% in 2018. Serious MRSA infections are commonly associated with poor clinical outcomes coupled with increased hospitalisation stay and cost. Therefore, early identification and appropriate empiric treatment of MRSA plays a crucial role in healthcare settings. However, the constant rise in multi-drug resistance to the currently available anti-MRSA agents as well as their compromised safety profile limits its clinical use to manage severe MRSA infections. This review article explores the implications of severe MRSA infections and inappropriate empirical therapy on the clinical as well as economic outcomes. In addition, it also highlights limitations of the currently available anti-MRSA agentsand the need for newer agents to manage multi drug resistant (MDR)gram positive infections.

Effect of vancomycin-loaded microbubbles combined with ultrasound targeted microbubble destruction technology on methicillin-resistant Staphylococcus aureus biofilms / 中华创伤杂志

Objective:To investigate the effect of vancomycin (Vm)-loaded microbubbles (MBs) combined with ultrasound targeted microbubble destruction (UTMD) technique on the morphological structure, thickness and bacterial viability of methicillin-resistant Staphylococcus aureus (MRSA) biofilms.Methods:Vm-MBs were prepared by thin film hydration. Sterile coverslips in a diameter of 13 mm were placed in 24-well plates to construct in vitro biofilm models using MRSA as the test strain, and the biofilm morphology was observed by naked eye and light microscopy after crystal violet staining. LIVE/DEAD, SYTO59 and DIL were used to stain biofilms and MBs, respectively. After staining, the biofilm morphology and position of the biofilm in relation to MBs were observed using laser confocal scanning microscopy. The biofilms were divided into control group, Vm group, Vm-MBs group, UTMD group and Vm-MBs+UTMD group according to the random number table method, with 9 samples in each group. After biofilms of each group were treated accordingly for 24 hours, the morphological and structural changes of biofilms in each group were observed using laser confocal scanning microscopy and scanning electron microscopy following LIVE/DEAD staining; the difference in biofilm density in each group was measured with the aid of an enzyme marker following crystal violet staining; the difference in biofilm thickness and bacterial viability in each group were observed by laser confocal scanning microscopy. Results:The prepared Vm-MBs met the experimental requirements. The constructed biofilm model observed by naked eye, light microscopy and laser confocal scanning microscopy showed that the biofilm structure was dense with a relatively uniform thickness of (13.8±0.2)nm, a small amount of dead bacteria inside the membrane and the percentage of live bacteria of (94.9±0.3)%. Laser confocal scanning microscopy showed that MBs could penetrate into deeper layers of biofilms. After the respective treatment was given to each group for 24 hours, Laser confocal scanning microscopy and scanning electron microscopy following LIVE/DEAD staining showed that the biofilm morphological structure was most significantly disrupted in Vm-MBs+UTMD group compared to control, Vm, Vm-MBs and UTMD groups. In Vm-MBs+UTMD group, a large number of dead bacteria was observed, with only a few scattered planktonic bacteria and irregular changes in cell membrane morphology. Crystal violet staining showed that the biofilm density was significantly lower in Vm-MBs+UTMD group compared to control group ( P<0.05), while the differences between Vm, Vm-MBs and UTMD groups were not statistically significant (all P>0.05). Laser confocal microscopy showed that the biofilm thickness was thinner in Vm-MBs, UTMD and Vm-MBs+UTMD groups compared to control group (all P<0.05), with no significant difference between Vm group and control group ( P>0.05) and that the biofilm thickness was thinner in Vm-MBs+UTMD group compared to Vm, Vm-MBs and UTMD groups (all P<0.01), with no significant differences between the other groups (all P>0.05). Bacterial activity in Vm, Vm-MBs, UTMD and Vm-MBs+UTMD groups was significantly lower than that in control group (all P<0.01), with lower in Vm-MBs+UTMD group compared to Vm, Vm-MBs and UTMD groups (all P<0.01), but without significant difference between the other groups (all P>0.05). Conclusion:Vm-MBs combined with UTMD technology can effectively destroy the biofilm morphological structure to reduce biofilm thickness. Meanwhile, Vm-MBs combined with UTMD technology can release antibiotics and significantly decrease bacterial viability to improve antibiotic bactericidal efficacy.

A confirmed case of menstrual cup-associated toxic shock syndrome: A Philippine perspective / Philippine Journal of Obstetrics and Gynecology

@#Menstrual toxic shock syndrome (TSS) is a severe, fatal, superantigen toxin‑mediated illness, which leads to multiorgan system failure early in its course. At the time of writing, there are no local data available on menstrual cup‑associated TSS. Reported is a 30‑year‑old healthy Filipino, diagnosed as a case of menstrual cup‑associated TSS. Diagnosis was confirmed by case definition criteria and supported by vaginal discharge culture of methicillin‑resistant Staphylococcus aureus. The patient was treated empirically with antibiotics that led to successful treatment outcomes with no recurrence. At present, when women empowerment is of utmost importance, we support women’s decisions pertaining to their health, including their choice of menstrual hygiene products. This case is reported to raise awareness, promote wellness and safety among menstrual cup users and to educate clinicians on the course and management of menstrual cup associated toxic shock syndrome to prevent its catastrophic sequelae.

Antibacterial potential of indigenous medicinal plants against methicillin-resistant Staphylococcus aureus isolated from septic wounds

Aims@#This study was aimed to screen indigenous medicinal plants for their antibacterial potential against methicillin-resistant Staphylococcus aureus (MRSA).@*Methodology and results@#Three indigenous plants (Nigella sativa, Zingiber officinale and Calotropis procera) and thymoquinone were screened for antibacterial activity against MRSA, isolated from septic wounds of patients admitted to Mayo Hospital Lahore, Pakistan. Isolated bacteria were screened for methicillin and cefoxitin resistance by the Kirby-Bauer method, followed by mecA gene-specific polymerase chain reaction (PCR). Confirmed MRSA was processed for antibacterial activity of plant extracts and thymoquinone followed by cytotoxicity assay of plant extract having least minimum inhibitory concentration (MIC) value. Out of total samples (n=100), S. aureus (29%), MRSA (26%) and vancomycin-resistant S. aureus (VRSA) (21.7%) isolates were recovered based on morphology, biochemical profile and antibiotic susceptibility testing. Nigella sativa showed the highest antibacterial activity (10.06 ± 6.53 mm) against MRSA followed by Z. officinale (4.06 ± 3.72 mm) and C. procera (3.65 ± 3.33 mm) in comparison to standard thymoquinone (17.93 ± 10.14 mm). The least MIC value recorded was for Z. officinale at 36.89 ± 3.75 μg/mL. Zingiber officinale was the most effective antibacterial agent, followed by N. sativa and C. procera and non-toxic for eukaryotic cells at all tested concentrations (1500 μg/mL to 2.92 μg/mL).@*Conclusion, significance and impact of study@#It was concluded that Z. officinale may be used as an effective alternative for treating septic wound infection in local or topical preparations. As pathogenic S. aureus is becoming life-threatening among antibiotic-resistant bacteria and traditional plants are in used for centuries to treat septic wound infections.

Effect of Fufang Huangbai Fluid Paint on Virulence and Biofilm of Methicillin-resistant Staphylococcus aureus / 中国实验方剂学杂志

ObjectiveTo study the virulence and biofilm inhibition effect of Fufang Huangbai Fluid Paint （FFHBFP） on methicillin-resistant Staphylococcus aureus （MRSA）， and to explore the antibacterial effect of FFHBFP on MRSA， which provides a theoretical basis and reference for clinical medication. MethodFirstly， the microdilution method and time–growth curve were used to determine the minimum inhibitory concentration （MIC） of FFHBFP and vancomycin （VAN） against MRSA and the effect on bacterial growth. The effects of FFHBFP and VAN on the inhibition of MRSA virulence factor lipase and restoration of hydrogen peroxide （H2O2） sensitivity were detected under sub-minimum inhibitory concentration （sub-MIC）. The inhibitory effect of FFHBFP and VAN on MRSA biofilm formation and maturation was detected by the microplate method. The morphological changes of mature biofilms before and after administration were observed under a scanning electron microscope （SEM）. Real-time polymerase chain reaction （Real-time PCR） was utilized to detect the effect of 50.600 g·L-1 concentration of FFHBFP on the expression of MRSA virulence gene crtM and biofilm-forming genes fnbA and icaA. Finally， molecular docking technology was used to predict the mechanism of potential antibacterial active ingredients of FFHBFP in inhibiting the virulence and biofilm of MRSA. ResultThe MIC of VAN was 2 mg·L-1， and VAN below 1 mg·L-1 exerted no effect on MRSA growth. The MIC of FFHBFP was not determined， while the 101.200-202.400 g·L-1 original solution inhibited MRSA growth. Compared with the blank group and the VAN group， sub-MIC （25.300-50.600 g·L-1 original solution） inhibited lipase and recovered MRSA sensitivity to H2O2 （P<0.01）. The results of the microplate method showed that FFHBFP （25.300-202.400 g·L-1 original solution） inhibited biofilm formation and maturation （P<0.05， P<0.01）. The SEM exhibited that FFHBFP made the structure of biofilm loose and the size of the bacteria varied. FFHBFP at 50.600 g·L-1 concentration can inhibit the expression of related virulence genes and biofilm-forming genes （P<0.05， P<0.01）， and molecular docking results also showed that the main antibacterial active ingredients in FFHBFP have good binding ability to the target. ConclusionFFHBFP that cannot directly kill MRSA exerts clinical efficacy by impairing virulence expression， biofilm formation， and other pathogenic properties.

Portación nasal, antibiotipo y genotipo de cepas de Staphylococcus aureus aisladas en estudiantes de Medicina y de Enfermería Campus San Felipe, Universidad de Valparaíso, Chile, durante el año 2017 / Nasal carriage, antibiotype and genotype of isolated Staphylococcus aureus from Medicine and Nursing students of Campus San Felipe, University of Valparaiso, Chile, during 2017

INTRODUCCIÓN. Staphylococcus aureus es parte de la microbiota nasal en 20-30% de la población general, colonización que constituye un reservorio para su transmisión, lo que es preocupante en cepas resistentes a meticilina (SARM). OBJETIVO: Determinar la prevalencia de S. aureus en estudiantes de Medicina y Enfermería del Campus San Felipe y caracterizar sus aislamientos. MATERIAL Y MÉTODOS: El 2017 se midió la portación nasal a 225 estudiantes, a las cepas aisladas se le analizó su antibiotipo por difusión en agar, la relación clonal por electroforesis de campo pulsado y MLST. En SARM se determinó el cassette SCCmec y gen de la leucocidina de Panton-Valentine. RESULTADOS: 61 estudiantes portaron S. aureus (27,1%) incluyendo dos cepas SARM (0,9%). Staphylococcus aureus mostró resistencia a penicilina (75%), eritromicina (14%) y clindamicina (10%), cloranfenicol (1,6%) y levofloxacina, oxacilina, cefoxitina (3,3%). Se diferenciaron diecinueve pulsotipos y el secuenciotipo coincidió con complejos clonales descritos a nivel mundial en portadores de S. aureus: CC30, CC8, CC97, CC15, CC22 y CC1. Las dos cepas SARM correspondieron con los clones chileno/cordobés y USA100NY/J, ambas del CC5. CONCLUSIÓN: La portación nasal de S. aureus y SARM en los estudiantes coincidió con la portación en la población general y las cepas sensibles a meticilina mostraron diversidad clonal y alta susceptibilidad antimicrobiana, exceptuando a penicilina.

BACKGROUND: Staphylococcus aureus is part of the nasal microbiota in 20-30% of the population. This colonization is also a reservoir for its dissemination, which is worrying in the case of strains with resistance to methicillin (MRSA). AIM: To determine S. aureus nasal carriage in nursing and medical students of San Felipe Campus and characterize theirs isolates. METHODS: During 2017, nasal swabs were taken from 225 students and seeded in salt manitol agar. Antibiotypes were determined by agar diffusion and the genetic clonality was assessed by PFGE and MLST in isolated S. aureus. SCCmec cassette and Panton-Valentine leukocidin gene (pvl) presence were determined in the MRSA isolates. RESULTS: 61 students carried S. aureus (27.1%) including two MRSA strains (0.9%). S. aureus showed resistance to penicillin (75%), erythromycin (14%) and clindamycin (10%), chloramphenicol (1.6%) and levofloxacin, oxacillin, cefoxitin (3.3%). Nineteen PFGE-types were differentiated, and their sequence-types coincided with main clonal complexes described in S. aureus carriers from different places worldwide: CC30, CC8, CC97, CC15, CC22 and CC1. MRSA strains belonged to CC5 and they corresponded to the Chilean/Cordobes and USA100NY/J clones. CONCLUSION: Nasal carriage of S. aureus and MRSA in students, coincided with the general population and sensitive-methicillin strains showed clonal diversity and high antimicrobial susceptibility except for penicillin.

Colonization of methicillin-resistant Staphylococcus aureus among healthcare students: an integrative review

ABSTRACT BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infection is a worldwide concern given its presence even in non-hospitalized healthy individuals, such as university students. OBJECTIVE: To identify in the literature the prevalence of colonization by MRSA among healthcare students. DESIGN AND SETTING: Integrative review of the literature conducted in Universidade Federal do Piauí. METHOD: A search for primary studies was performed in the following databases: Medical Literature Analysis and Retrieval System on-line; Cumulative Index to Nursing and Allied Health Literature; Web of Science; Scopus; and LILACS. RESULTS: This review included 27 studies that demonstrated MRSA infection prevalence ranging from 0.0 to 15.3% among students. CONCLUSION: The prevalence of colonization of MRSA among healthcare students is high, and the nasal cavity was cited as an important reservoir location for these microorganisms.

Actividad antimicrobiana de la peroxiadenosina en cultivos in vitro de Staphylococcus aureus resistente a meticilina / Antimicrobial activity of peroxyadenosine in vitro culture of resistant methicillin Staphylococcus aureus

RESUMEN Fundamento : las infecciones asociadas a la asistencia sanitaria y de la comunidad causadas por Staphylococcus aureus resistente a la meticilina, constituyen un problema de salud en el mundo. Esta situación se asocia al uso indiscriminado de antimicrobianos y a la mutagénesis bacteriana, por tanto, el desarrollo de nuevos productos con actividad antimicrobiana constituye una prioridad para Cuba. Objetivo : evaluar la actividad antimicrobiana de la peroxiadenosina en cultivo in vitro de Staphylococcus aureus resistente a la meticilina. Métodos : se realizó un estudio experimental de laboratorio en un modelo biológico (cultivo microbiano) en el Hospital Universitario Amalia Simoni de la provincia Camagüey, desde enero de 2016 hasta julio de 2020. La muestra se conformó con 60 cultivos biológicos de Staphylococcus aureus resistentes a la meticilina, mediante un muestreo aleatorio simple, distribuidos en dos grupos, cada uno con 30 cultivos. Un grupo correspondió a una cepa salvaje de Staphylococcus aureus resistentes a la meticilina, obtenida de la colección de cultivos del hospital y el otro a la cepa de referencia (ATCC 25923) de la American Type Culture Collection. Se estudiaron las variables: formación y concentración de la peroxiadenosina, preservación de la estructura aromática de la adenosina y el patrón de susceptibilidad a la meticilina. Resultados : la peroxiadenosina se formó a partir de la interacción del peróxido de hidrógeno con la adenosina. Los cultivos de Staphylococcus aureus resistentes a la meticilina se mostraron sensibles a las concentraciones de peroxiadenosina sin diluir y 1:2, demostrado por la presencia de halos de inhibición en el cultivo. Conclusiones : la inhibición del crecimiento de Staphylococcus aureus resistentes a la meticilina por la peroxiadenosina sugiere su evaluación como un nuevo producto antibacteriano eficaz contra este microorganismo.

ABSTRACT Background: infections associated with healthcare and the community caused by methicillin-resistant Staphylococcus aureus (MRSA) constitutes a health problem in the world. This situation is associated with the indiscriminate use of antimicrobials and bacterial mutagenesis, therefore, the development of new products with antimicrobial activity is a priority for Cuba. Objective: to evaluate the antimicrobial activity of peroxyadenosine in vitro culture of MRSA. Methods: an experimental laboratory study was carried out in a biological model (microbial culture) at the Amalia Simoni Hospital in Camagüey province, from January 2016 to July 2020. The sample consisted of 60 biological cultures through simple random sampling, distributed in two groups with 30 crops of each investigated layer. One group corresponded to a wild MRSA strain, obtained from the hospital culture collection and the other to the reference strain (ATCC 25923) from the American Type Culture Collection. The studied variables were: formation and concentration of peroxyadenosine, preservation of the aromatic structure of adenosine and the pattern of susceptibility to methicillin. Results: peroxyadenosine was formed from the interaction of hydrogen peroxide with adenosine. The MRSA cultures were sensitive to 1: 2 undiluted peroxyadenosine concentrations, demonstrated by the presence of inhibition halos in the culture. Conclusions: the inhibition of MRSA growth by peroxyadenosine suggests its evaluation as a new antibacterial product effective against this microorganism.

Staphylococcus aureus Resistentes a meticilina en animales de granja en Suramérica: una revisión sistemática

Resumen La interacción entre los seres humanos y los animales de granja aumenta el riesgo de contagio con patógenos causantes de enfermedades zoonóticas. Entre estos patógenos destacan las cepas de Staphylococcus aureus resistentes a meticilina (SARM). Inicialmente identificadas como causantes de enfermedades intrahospitalarias, hoy se sabe que estas cepas también se transmiten en la comunidad infectando, además, a distintos animales. Lamentablemente, existen pocos estudios en torno a este importante tema de salud pública, particularmente en América del Sur. Este trabajo sistematiza la información disponible en relación con la ocurrencia de cepas SARM en animales de granja en dicha región. Para ello, se realizó una revisión de la información disponible en bases de datos como Scopus, Medline y Scielo, de acuerdo a las recomendaciones de la declaración PRISMA. Se incluyeron artículos publicados en los últimos diez años, que hagan referencia la ocurrencia de cepas SARM en animales de granja, en países de América del Sur. De un total de 65 artículos, se seleccionaron 19. De estos,13 se realizaron en Brasil, dos en Ecuador, uno en Chile, Uruguay y Perú, respectivamente; un último trabajo incluye datos de varios países. La mayoría de los estudios caracterizaron cepas SARM aisladas a partir de ganado vacuno, siendo los cerdos los animales que ocupan la segunda posición de interés. En muchos de estos estudios se emplearon técnicas de biología molecular. Aunque en general no fueron reportados datos importantes como la prevalencia o el período de muestreo, destaca una elevada ocurrencia de cepas SARM multirresistentes en estos animales.

Abstract The interaction between humans and farm animals increases the risk of infection with a zoonotic pathogen. Among these pathogens, methicillin-resistant Staphylococcus aureus (MRSA) strains stand out. Initially identified as the cause of hospital-acquired diseases, it is acknowledged nowadays that these strains are also transmitted in the community, being able to infect different animals. Unfortunately, few studies on this important public health issue have been published, particularly concerning the South American region. Here we systematize the available information on the occurrence of MRSA strains in farm animals in South-American countries. For this, a systematic review of the information available in the bibliographic databases Scopus, Medline and Scielo was carried out, following PRISMA standards. Articles published in the last ten years referring the occurrence of MRSA strains in farm animals in South America were included. From a total of 65 articles, 19 were selected. Of these, 13 were conducted in Brazil, two in Ecuador, one in Chile, Uruguay and Peru, respectively; a last study includes data from several countries. Most of the studies characterized MRSA strains isolated from cattle, with pigs being the second most important animal of interest. Molecular biology techniques were used in many of these studies. Although in many cases important data such as prevalence or sampling period were not reported, a high occurrence of multidrug-resistant MRSA strains in these animals stands out.

Resumo A interação entre humanos e animais de fazenda aumenta o risco de infecção com um agente zoonótico patogénico. Entre estes agentes patogénicos destacam-se as cepas de Staphylococcus aureus resistente à meticilina (MRSA). Inicialmente identificadas como a causa de doenças adquiridas em hospitais, reconhece-se hoje em dia que estas cepas também são transmitidas na comunidade, podendo infectar diferentes animais. Infelizmente, poucos estudos sobre esta importante questão de saúde pública foram publicados, particularmente no que diz respeito à região da América do Sul. Aqui sistematizamos a informação disponível sobre a ocorrência de MRSA em animais de fazenda em países sul-americanos. Para tal, foi realizada uma revisão sistemática da informação disponível nas bases de dados bibliográficas Scopus, Medline e Scielo, seguindo as normas PRISMA. Foram incluídos artigos publicados nos últimos dez anos, referindo a ocorrência de cepas MRSA em animais de fazenda na América do Sul. De um total de 65 artigos, foram seleccionados 19. Destes, 13 foram realizados no Brasil, dois no Equador, um no Chile, Uruguai e Peru, respectivamente; um último estudo inclui dados de vários países. A maioria dos estudos caracterizou cepas de MRSA isoladas de bovinos, sendo os suínos o segundo animal de maior interesse. Em muitos de estos artigos foram utilizadas técnicas de biologia molecular. Embora em muitos casos não tenham sido comunicados dados importantes, tais como prevalência ou período de amostragem, destaca-se a elevada ocorrência de cepas multirresistentes de MRSA nestes animais.

Efecto antibacteriano in vitro de extractos de Caesalpinia spinosa sobre cepas de Staphylococcus aureus resistentes a antibióticos betalactámicos / In vitro antimicrobial effect of Caesalpinia spinosa extracts against betalactam antibiotics resistant Staphylococcus aureus strains

Objetivo. Determinar el efecto antimicrobiano de extractos etanólicos de Caesalpinia spinosa sobre cepas de Staphylococcus aureus penicilino y meticilino resistentes. Métodos. Se utilizaron las cepas de S. aureus ATCC 11632 y 33592, los extractos etanólicos de hojas, vainas y semillas de C. spinosa, se obtuvieron por maceración en concentraciones de 25%, 50%, 75% y 100%. Se utilizó el método de Kirby-Bauer, los discos de papel filtro se cargaron con los extractos y se depositaron sobre el medio, inoculado con una suspensión de S. aureus a 0,5 McFarland. El control positivo fueron discos de ampicilina y el control negativo discos impregnados con etanol. Después de 24 horas se midieron los diámetros de los halos con un calibrador Vernier. Resultados. Se registraron halos de hasta 18 mm de diámetro con los extractos de hojas al 100%, 17 mm con extractos de vainas y 14 mm con extractos de semillas sobre S. aureus ATCC 33592. En el caso de la cepa ATCC 11632, se registraron halos de hasta 14 mm con extractos de hojas y vainas al 100%, y de hasta 8 mm con extractos de semillas. La prueba de ANOVA indicó que existieron diferencias significativas entre los halos obtenidos con los diferentes tipos de extractos, a diferentes concentraciones. Conclusión. Se determinó que todos los extrac- tos de C. spinosa poseen actividad antimicrobiana sobre las dos cepas estudiadas, con un patrón directamente proporcional entre el efecto y la concentración.

Objective. To determine the antimicrobial effect of ethanolic extracts from Caesalpinia spinosa against penicillin and methicillin resistant strains of Staphylococcus aureus penicillin and methicillin. Methods. S. aureus ATCC 11632 and 33592 strains were used, ethanolic extracts from C. spinosa leaves and pods were obtained by maceration at concentrations of 25%, 50%, 75% and 100%. The Kirby-Bauer method was used, where filter paper discs were loaded with leaf, pod and seed extracts and deposited on the medium, inoculated with a 0.5 McFarland suspension of S. aureus. Ampicillin discs were used as positive con- trol and ethanol-impregnated discs as negative control. After 24 hours, the diameters of the halos were measured with a Vernier caliper. Results. Haloes up to 18 mm in diameter with 100% leaf extracts, 17 mm with pod extracts and 14 mm with seed extracts were recorded against S. aureus ATCC 33592; for ATCC strain 11632, haloes up to 14 mm with 100% leaf and pod extracts and up to 8 mm with seed extracts were recorded. The ANOVA test indicated significant differences between the inhibition halos obtained with the different types of extracts, at different concentrations. Conclusion. It was determined that all C. spinosa extracts possess antimicrobial activity against the two strains studied, with a pattern directly proportional between the effect and concentration.