RÉSUMÉ
Abstract The aim of this study was to characterize phenotypically and genotypically 27 mecApositive Staphylococcus aureus strains with oxacillin MICs of ≤2 g/ml by Vitek 2, isolated indifferent regions of Uruguay. Susceptibility to oxacillin and cefoxitin was studied by gradient dif-fusion, disk diffusion to cefoxitin, and Phoenix and MicroScan systems. PBP2a was determined.SCCmec typing was performed and the isolates were compared by PFGE. Twenty-six isolateswere susceptible to oxacillin; one strain was susceptible to cefoxitin by disk diffusion and 3strains by gradient diffusion. Phoenix and MicroScan panels detected methicillin resistance in25 and 27 strains, respectively. Twenty-six strains tested positive for PBP2a. Twenty-six strainscarried SCCmec V and 24 belonged to pulsotype A. One strain carried SCCmec IV and did notbelong to pulsotype A. Cefoxitin disk diffusion test and PBP2a detection correctly identified 26of these 27 strains as MRSA. PFGE results suggest the dissemination of a cluster of MRSA carryingSCCmec V.
Resumen El objetivo de este estudio fue caracterizar fenotípicamente y genotípicamente 27 cepas de Staphylococcus aureus positivas para mecA y con CIM de oxacilina <2 pg/ml según Vitek 2, obtenidas en diferentes regiones del país. La sensibilidad frente a la oxacilina y la cefoxitina se estudió por difusión en gradiente, por disco-difusión (cefoxitina) y por los sistemas Phoenix y MicroScan. Se analizó la portación de PBP2a, se realizó la tipificación de SCCmec y las cepas se compararon mediante PFGE. Resultaron sensibles a oxacilina por difusión en gradiente 26 cepas; una fue sensible a cefoxitina por disco-difusión y 3 lo fueron por difusión en gradiente. Los sistemas Phoenix y MicroScan detectaron resistencia a meticilina en 25 y 27 cepas, respectivamente. Asimismo, 26 cepas portaban PBP2a y 26 cepas mostraron presencia de SCCmec V, 24 correspondieron al pulsotipo A. Una portaba SCCmec IV y no perteneció al pulsotipo A. La prueba de disco-difusión con cefoxitina y la detección de PBP2a identificaron 26 de 27 cepas como MRSA. La PFGE sugiere la diseminación de un grupo MRSA con SCCmec V. © 2022 Asociación Argentina de Microbiología. Publicado por Elsevier Espana, S.L.U. Este es un artículo Open Access bajo la licencia CC BY-NC-ND (https://creativecommons.org/licenses/by-nc-nd/4.0/).
RÉSUMÉ
Staphylococcus aureus es un microorganismo que posee características particulares de virulencia y resistencia a los antibióticos. Las infecciones que produce, ocurren mayormente en personas inmunodeprimidas que podrían presentar severas consecuencias, a pesar de la terapia antimicrobiana. Objetivo. Determinar la resistencia de Staphylococcus aureus aislados en ambientes nosocomiales mediante métodos convencionales y moleculares. Materiales y métodos. el estudio presenta un enfoque cuantitativo, investigación de campo, observacional de corte transversal. Se analizó 200 muestras de aislados de ambientes nosocomiales mediante métodos fenotípicos (antibiograma por la técnica de Kirby Bauer) y genotípicos (genes de resistencia blaZ, mecA, y vanA por PCR punto final). Resultados. Los resultados de las pruebas de susceptibilidad antibiótica mostraron que el 100% de las cepas de S. aureus aisladas, fueron resistentes a oxacilina y penicilina g; y sensibles a vancomicina. Conclusiones. los resultados obtenidos en este estudio evidenciaron la presencia de SARM en las diferentes áreas hospitalarias, constituyéndose en un factor de riesgo de transmisión horizontal entre el personal sanitario y los pacientes, razón por la cual es de gran importancia evaluar su prevalencia y establecer medidas rigurosas de prevención y control de su diseminación, para disminuir el riesgo de nuevas infecciones.
Staphylococcus aureus is a microorganism with particular characteristics of virulence and resistance to antibiotics. The infections it produces occur mostly in immunocompromised individuals who may present severe consequences, despite antimicrobial therapy. Objective. To determine the resistance of Staphylococcus aureus isolated in nosocomial environments by conventional and molecular methods. Materials and methods. The study presents a quantitative, field research, observational, cross-sectional approach. Two hundred samples of isolates from nosocomial environments were analyzed by phenotypic (antibiogram by Kirby Bauer technique) and genotypic (resistance genes blaZ, mecA, and vanA by endpoint PCR) methods. Results. The results of the antibiotic susceptibility tests showed that 100% of the S. aureus strains isolated were resistant to oxacillin and penicillin g; and sensitive to vancomycin. Conclusions. the results obtained in this study showed the presence of MRSA in the different hospital areas, constituting a risk factor for horizontal transmission between health personnel and patients, which is why it is of great importance to evaluate its prevalence and establish rigorous measures for the prevention and control of its dissemination, in order to reduce the risk of new infections.
O Staphylococcus aureus é um microorganismo com características particulares de virulência e resistência a antibióticos. As infecções ocorrem principalmente em indivíduos imunocomprometidos que podem ter conseqüências graves, apesar da terapia antimicrobiana. Objetivo. Para determinar a resistência de Staphylococcus aureus isolado em ambientes nosocomiais usando métodos convencionais e moleculares. Materiais e métodos. O estudo apresenta uma abordagem quantitativa, pesquisa de campo, observacional, transversal. Duzentas amostras de isolados de ambientes nosocomiais foram analisadas pelos métodos fenotípico (antibiograma pela técnica de Kirby Bauer) e genotípico (genes de resistência blaZ, mecA, e vanA pelo método de PCR de ponto final). Resultados. Os resultados dos testes de suscetibilidade aos antibióticos mostraram que 100% das cepas de S. aureus isoladas eram resistentes à oxacilina e penicilina g; e sensíveis à vancomicina. Conclusões. Os resultados obtidos neste estudo mostraram a presença de MRSA nas diferentes áreas hospitalares, constituindo um fator de risco para a transmissão horizontal entre o pessoal de saúde e os pacientes, razão pela qual é de grande importância avaliar sua prevalência e estabelecer medidas rigorosas para a prevenção e controle de sua disseminação, a fim de reduzir o risco de novas infecções.
Sujet(s)
Staphylococcus aureusRÉSUMÉ
Uno de los microrganismos más importantes en Infecciones Asociadas a la Atención en Salud (IAAS) es Staphylococcus aureus, una bacteria aerobia Gram positiva, resistente a diferentes condiciones ambientales. Objetivo. Identificar Staphylococcus aureus y su resistencia a los principales antibióticos Betalactámicos, aislada en áreas inertes. Materiales y métodos. Se realizó análisis fenotípico, antibiograma y métodos moleculares como: Extracción de ADN mediante Lisis Alcalina, identificación molecular para la amplificación de los genes tanto de identificación de la bacteria (nucA y femB), como de resistencia de antibióticos (blaZ, mecA y vanA) mediante PCR punto final, la separación de los amplicones se realizó mediante electroforesis en gel de Agarosa, los productos de la PCR se revelaron mediante la utilización de transiluminador UV. Resultados. De 200 muestras tomadas se obtuvo dos muestras positivas (1%) para Staphylococcus aureus, con el 100% de resistencia a penicilina y sensible a todos los demás antibióticos testeados. Conclusiones. La identificación de la bacteria y su resistencia hoy en día se realiza mayormente mediante métodos moleculares, lo cual no descarta la identificación fenotípica que, en este caso, determinó resultados importantes como lo es la prueba D-test positivo. La resistencia a fármacos betalactámicos se considera como un serio problema de salud, por lo tanto, se requiere de una vigilancia epidemiológica constante.
Staphylococcus aureus is one of the most important microorganisms related to Health Care Associated Infections (HCAI), it is a Gram-positive aerobic bacterium, highly resistant to the outer environment. Objective. Identify Staphylococcus aureus and its resistance to the most common beta-lactam antibiotics in isolated, inert areas. Materials and methods. Phenotypic analysis, antibiogram and molecular testing such as: DNA extraction by Alkaline Lysis, molecular identification for the amplification of genes both for identification of Staphylococcus aureus (nucA and femB), and for antibiotic resistance (blah, mega and vanA) by PCR, the disassociation of the amplicons was preforming by Agarose gel electrophoresis and results were shown in a UV translluminator. Results. From the 200 samples taken, two showed positive (1%) for Staphylococcus aureus, with 100% penicillin-resistant and sensitive to all other antibiotics tested. Conclusions. Nowadays identification of the bacteria and its resistance is carried out mostly through molecular testing, ruling out phenotypic identification, which in this case it determined important results such as the positive D-test. Resistance to beta-lactam drugs is considered a serious health issue, therefore it requires a safer epidemiological vigilance, an increase in sensitivity testing and the accuracy of results. It is recommended to carry out the D-test in laboratories to identify resistance mechanisms and to guide health personnel to select the best option regarding specific and effective treatment for patients affected with MRSA.
Um dos microrganismos mais importantes em Infecções Associadas à Saúde (HAIs) é o Staphylococcus aureus, uma bactéria aeróbica gram-positiva resistente a diferentes condições ambientais. Objetivo. Identificar Staphylococcus aureus e sua resistência aos principais antibióticos beta-lactam, isolados em áreas inertes. Materiais e métodos. Análise fenotípica, antibiograma e métodos moleculares foram realizados tais como: extração de DNA por Alkaline Lysis, identificação molecular para a amplificação dos genes tanto da identificação da bactéria (nucA e femB), e resistência a antibióticos (blaZ, mecA e vanA) pelo ponto final da PCR, a separação dos amplicons foi realizada por eletrofose em gel de Agarose, os produtos PCR foram revelados usando transiluminador UV. Resultados. De 200 amostras colhidas, duas amostras positivas (1%) foram obtidas para o Staphylococcus aureus, com 100% de resistência à penicilina e sensível a todos os outros antibióticos testados. Conclusões. A identificação da bactéria e sua resistência hoje é realizada principalmente por métodos moleculares, o que não exclui a identificação fenotípica que, neste caso, determinou resultados importantes como o teste D positivo. A resistência aos medicamentos beta-lactam é considerada um grave problema de saúde, portanto, é necessária uma vigilância epidemiológica constante.
Sujet(s)
Bactéries , Staphylococcus aureus résistant à la méticillineRÉSUMÉ
Introducción: Staphylococcus aureus, es la principal causa de bacteriemia infecciosa y endocarditis, así como de infecciones osteoarti-culares, de piel y tejidos blandos, su reservorio principal es la mucosa nasal. Los trabajadores de la salud son una fuente importante de transmisión de S. aureus y S. aureus resistente a la meticilina (SARM). Objetivo: determinar la presencia de Staphylococcus aureus y SARM en la fosa nasal de auxiliares de enfermería en la ciudad de Bogotá. Materiales y métodos: estudio descriptivo de corte transversal, en auxiliares de enfermería de diferentes instituciones hospitalarias y clínicas en la ciudad de Bogotá, Colombia. Se realizó un muestreo aleatorio. El tamaño de la muestra fue de 491 hisopados de la fosa nasal derecha de igual número de auxiliares de enfermería que al momento del estudio se encontraban laborando a nivel clínico. Se tomó un intervalo de confianza del 95% y error máximo admisible del 5%, se consideró el valor de p= 0,5. Se realizó un estudio de frecuencias y determinación de prevalencias mediante un análisis univariado. Resultados: la presente investigación encontró queel 28,5% de los participantes fueron portadores del Staphylococcus aureus y el 6,1% fueron SARM. Conclusiones: la colonización por Staphylococcus aureus y SARM es frecuente en auxiliares de enfermería.
Introduction: Staphylococcus aureus is a human pathogen of clinical severe relevance, it is the leading cause of infectious bacteremia and endocarditis, as well as osteoarticular, skin, and soft tissue infections; its, main reservoir is the nasal mucosa. Healthcare workers are a significant source of transmission of S. aureus and methicillin-resistant S. aureus (MRSA). Objective: To determine the presence of Staphylococcus aureus and MRSA in the nostrils of nursing assistants in Bogotá's city. Materials and methods: a descriptive cross-sec-tional study in nursing assistants from different hospitals and clinical institutions in Bogotá's city, Colombia. Random sampling was carried out. The sample size was 491 swabs from the right nostril from the same number of nursing assistants working at the clinical level at the time of the study. A confidence interval of 95% and maximum permissible error of 5% were taken, the value of p = 0.5 was considered. A study of frequencies and determination of prevalence was carried out through univariate analysis. Results: the present investigation found that 28.5% of the participants were carriers of Staphylococcus aureus, and 6.1% were methicillin-resistant S. aureus(MRSA). Conclusions: colonization by Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) is common in nursing assistants.
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Introduction: Considering the lack of specific treatments for neuropathic pain, this study aimed to evaluate the effect of a single dose of adenosine A3 receptor IB-MECA on inflammatory and neurotrophic parameters in rats subjected to a neuropathic pain model. Methods: 64 adult male Wistar rats were used. Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve and the treatment consisted of a 0.5 µmol/kg dose of IB-MECA, a selective A3 adenosine receptor agonist, dissolved in 3% DMSO; vehicle groups received DMSO 3% in saline solution, and morphine groups received 5 mg/kg. Cerebral cortex and hippocampus IL-1ß, BDNF, and NGF levels were determined by Enzyme-Linked Immunosorbent assay. Results: The main outcome was that a single dose of IB-MECA was able to modulate the IL-1ß hippocampal levels in neuropathic pain induced by CCI and the DMSO increased IL-1ß and NGF hippocampal levels in sham-operated rats. However, we did not observe this effect when the DMSO was used as vehicle for IB-MECA, indicating that IB-MECA was able to prevent the effect of DMSO. Conclusions: Considering that the IL-1ß role in neuropathic pain and the contributions of the hippocampus are well explored, our result corroborates the relationship between the A3 receptor and the process of chronic pain maintenance.
Sujet(s)
Animaux , Mâle , Rats , Névralgie/diagnostic , Névralgie/métabolisme , Facteur de croissance nerveuse/génétique , Facteur de croissance nerveuse/métabolisme , Récepteur A3 à l'adénosine/usage thérapeutiqueRÉSUMÉ
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.
Sujet(s)
Humains , Infections à staphylocoques/épidémiologie , Élève infirmier , Staphylococcus aureus résistant à la méticilline/génétique , Staphylococcus aureus/génétique , Tests de sensibilité microbienne , Chili , Agar-agar , Typage par séquençage multilocus , Génotype , Méticilline , Antibactériens/pharmacologieRÉSUMÉ
@#Introduction: S. haemolyticus is known to be commensals residing on human skin. However, their ability to develop as pathogens among the healthy community has becoming increasingly vital. Methods: In this study, a total of 49 non-duplicated samples of S. haemolyticus was isolated from the skin of healthy adults and confirmed via sodA gene sequencing method. Cefoxitin (30μg) disc diffusion test was performed to determine methicillin resistance among the S. haemolyticus isolates. The isolates were then subjected to mecA amplification and Staphylococcus Cassette Chromosome (SCCmec) typing of I, II, III, IV and V. Results: Interestingly, 59.2% of the S. haemolyticus commensal isolates were found to be methicillin-resistant (MRSH) while the remaining 40.8% was methicillin-sensitive (MSSH). Amplification of mecA gene showed that 43 isolates (87.8%) were positive while only six isolates were negative for the gene. A majority of the positive mecA isolates (90.7%) were discovered to harbour SCCmec Type II while the remaining 44.2% were Type V followed by 23.3% of Type I and 18.6% of Type IV. Only one of the isolates was found to be SCCmec Type III while another isolate, T187 was non-typeable. Conclusion: The data indicates the acquisition of SCCmec typing circulated among the commensal strains which could be a potential route of pathogenicity among the isolates.
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RESUMEN Objetivos: Tipificar el casette SCCmec en cepas de Staphylococcus aureus resistentes a meticilino (SARM) en aislados clínicos de centros de salud del Estado Aragua-Venezuela y comparar la presencia de los genotipos SCCmec entre los centros de salud del estado y según el tipo de infección. Materiales y métodos: Durante enero y agosto de 2015 se estudiaron 81 cepas SARM de cuatro centros de salud del estado de Aragua en Venezuela. La resistencia al meticilino se midió con el método de Kirby-Bauer con discos de oxacilina (1 µgr) y cefoxitina (30 µgr). El gen mecA y el SCCmec se analizaron por la técnica de reacción en cadena de polimerasa múltiple. Resultados: 55 aislados (67,9%) amplificaron el gen mecA, y 24 cepas (43,6%) amplificaron el SCCmec. El SCCmec I fue el más frecuente, seguido de SCCmecIV y SCCmec III, representaron el 62,5%, 25% y 12,5%, respectivamente. El SCCmec I fue predominante en el centro de salud A (80%), mientras que el SCCmec IV se encontró en el centro de salud B (60%) y C (100%). En el centro de salud D, 50% resultó ser SCCmec I y 50% SCCmec IVd. Se encontró relación entre el SCCmec y el centro de salud con significancia estadística. En infecciones de piel y tejidos blandos y en las respiratorias predominó el SCCmec I con 63,2% y 50% respectivamente. Conclusiones: La frecuencia de SCCmec I y IV permitirá establecer nuevas medidas en el uso y control de la resistencia a los antibióticos.
ABSTRACT Objective: Typify the SCCmec cassette in methicillin-resistant strains of Staphylococcus aureus in clinical isolates from health centers in the State of Aragua-Venezuela and compare the presence of SCCmec genotypes among the state health centers and according to the type of infection. Materials and methods: 81 MRSA strains from four health centers of the Aragua-Venezuela State were studied. Methicillin resistance was performed with the Kirby-Bauer method with oxacillin (1 µg) and cefoxitin (30 µg) disks. The mecA gene and SCCmec were analyzed by the multiple PCR technique. Results: Only 55 isolates (67.9%) amplified the mecA gene, and 24 strains (43.6%) amplified SCCmec. SCCmec type I was the most frequency, followed by SCCmec IV and SCCmec III, representing 62.5%, 25% and 12.5%, respectively. SCCmec I was predominant in health center A (80%), while in B and C 60% and 100% respectively were SCCmec IV. At health center D, 50% turned out to be SCCmec I and 50% SCCmec IVd. A relationship was found between the SCCmec and the health center with statistical significance. SCCmec I predominated in skin and soft tissue and respiratory infections with 63.2% and 50%, respectively. There was no association between genotype and type of infection with a p value greater than 0.05. Conclusions: The prevalence of SCCmec I and IV will allow establishing new measures in the use of antibiotics and epidemiological control.
Sujet(s)
Humains , Mâle , Femelle , Infections à staphylocoques , Staphylococcus aureus , Résistance microbienne aux médicaments , Chromosomes , Staphylococcus aureus résistant à la méticilline , Oxacilline , Infections de l'appareil respiratoire , Infections à staphylocoques/microbiologie , Infections à staphylocoques/épidémiologie , Venezuela , Venezuela/épidémiologie , Chromosomes/génétique , Épidémiologie moléculaire , Staphylococcus aureus résistant à la méticilline/isolement et purification , Staphylococcus aureus résistant à la méticilline/génétique , Génotype , AntibactériensRÉSUMÉ
ABSTRACT: Staphylococcus spp. are bacteria involved in human and animal infections. They are resistant to antimicrobials and have become a major public health concern. In recent years, there has been a significant increase in methicillin-resistant Staphylococcus strains and vancomycin is the drug of choice for the treatment of such isolates. However, the minimum inhibitory concentration (MIC) of vancomycin necessary to combat this microorganism has been showing an increase. The aim of the present study was to determine the susceptibility profile of the Staphylococcus spp. of domestic and wild animals to vancomycin, using the microdilution in broth and E-test® techniques, as well as comparing the results of both tests. Of the 50 isolates tested, 47 (94 %) were sensitive to vancomycin in the microdilution and 43 (86 %) were sensitive to vancomycin in the E-test®. Seven (14 %) isolates had an intermediate result showing a risk to public health since the detection of these isolates may precede the occurrence of isolates resistant to vancomycin. In addition, the mecA gene was detected in 78 % of the tested samples. Six of the seven isolates with intermediate resistance to vancomycin were carriers of the mecA gene, showing that these isolates had a potential risk of becoming resistant. Thus, control measures must be taken to prevent the spread of these isolates with intermediate resistance and preserve the effectiveness of this antimicrobial for the treatment of infections caused by multiresistant Staphylococcus spp.
RESUMO: Staphylococcus spp. são bactérias envolvidas em infecções de humanos e animais, resistentes a antimicrobianos e tem se tornado uma grande preocupação em saúde pública. Nos últimos anos houve um aumento significativo de Staphylococcus resistentes à meticilina e a vancomicina é a droga de escolha para o tratamento desses isolados, porém vem apresentando elevação nos valores de Concentração Inibitória Mínima (CIM) necessários para combater este microrganismo. O objetivo do presente trabalho foi determinar o perfil de suscetibilidade à vancomicina para isolados de Staphylococcus spp. de animais domésticos e silvestres pelas técnicas de Microdiluição em caldo e E-test®, bem como comparar os resultados de ambos os testes. Dos 50 isolados testados 47 (94%) foram sensíveis à vancomicina na Microdiluição e 43 (86%) foram sensíveis à vancomicina no E-test®. Sete (14%) isolados tiveram resultado intermediário demonstrando um risco à saúde pública visto que a detecção destes isolados pode preceder a ocorrência de isolados resistentes à vancomicina. Ademais o gene mecA foi detectado em 78% das amostras testadas, sendo que dos sete isolados com resistência intermediária à vancomicina, seis eram portadores do gene mecA, evidenciando que esses isolados possuem potencial risco de se tornarem resistentes. Dessa forma medidas de controle devem ser tomadas para evitar a propagação destes isolados com resistência intermediária e preservar a eficácia deste antimicrobiano para o tratamento de infecções causadas por Staphylococcus multirresitentes.
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Background: Antimicrobial resistance is a devastating question that threatens health globally. The extensive, indiscriminate and unnecessary consumption of antibiotics for humans, as well as wildlife and in agriculture; lead to the development of notoriously resistant Staphylococcus aureus; through possession of mecA gene, encoded by modified Penicillin binding protein (PBP2a); being labeled “Methicillin resistant Staphylococcus aureus”. Conventional phenotypic techniques for MRSA detection rely on standardization of cultural characteristics. The latex agglutination method can be adopted as an accurate strategy for rapid detection of MRSA. Methodology: A total of 713 consecutive, non-duplicate isolates of Staphylococcus aureus were processed. Methicillin resistance was determined using cefoxitin (30 µg) by Kirby-Bauer method following Clinical and Laboratory Standards Institute (CLSI) guideline, latex agglutination method; and PCR for mecA gene. Results: The results showed that out of 713 Staphylococcus aureus isolates, 12.90% isolates were detected as MRSA due to resistance to cefoxitin. By latex agglutination method, 87 (94.50%) were positive for PBP2a; while on PCR mecA gene was detected only in 82 (89.10%) MRSA isolates. When assessed with PCR (gold standard) the sensitivity and diagnostic accuracy of latex agglutination was 100% and 94.57%, respectively. Conclusion: Latex agglutination test can be used as a prompt and reliable diagnostic technique for mecA gene detection in MRSA isolates, where molecular methods are limited. This can effectively minimize the misdiagnosis of resistant strains, and over/misuse of antibiotics.
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Background & objectives: Although there are reports of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) across the globe, there is a lack of reliable data on hVISA in India. The present study was undertaken to determine the rate of hVISA among the methicillin-resistant Staphylococcus aureus (MRSA) isolates, and to compare the brain heart infusion agar with vancomycin 4 ?g/ml (BHIV4) method with population analysis profile-area under the curve (PAP-AUC) method for the detection of hVISA and to study the distribution of mobile genetic element that carries methicillin-resistance gene SCCmec (Staphylococcal cassette chromosome mec) types among these isolates. Methods: BHIV4 and PAP-AUC methods were employed to detect hVISA among 500 clinical isolates of MRSA. SCCmec typing of these isolates was performed by multiplex polymerase chain reaction. The clinical presentation, treatment with vancomycin and outcome was documented for patients with hVISA. Results: The rate of hVISA was 12.4 per cent by PAP-AUC method. Sensitivity, specificity, PPV, NPV and kappa agreement of BHIV4 with PAP-AUC was 58.06, 93.15, 54.55, 94.01 per cent and 0.498, respectively. The isolation of hVISA was significantly (P<0.01) higher in patients admitted to intensive care units and wards than in patients attending the outpatient departments. Only 38 per cent of the patients received vancomycin as therapy. Majority of the hVISA isolates carried SCCmec type V or IV. Interpretation & conclusions: The rate of hVISA isolation in our study was 12.4 per cent. The sensitivity of the BHIV4 screening test was low, and was in moderate agreement with PAP-AUC test. SCCmec type V was the predominant type seen in half of the isolates. More studies need to be done in different parts of the country on a large number of isolates to confirm our findings.
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Purpose To investigate the pathological features and prognostic value of tertiary lymphoid structure (TLS) formation in gastric cancer (GC) . Methods HE staining slides were reviewed to evaluate the TLS in 163 specimens from patients with GC in the Third Affiliated Hospital of Soochow University from 2006 to 2008. The validation cohort contained 63 randomly selected cases and immunohistochemical staining of MECA-79 was used to verify the accuracy of pathological assessment of TLS. Results TLS score and MECA-79 immunohistochemical staining showed significant correlation (P = 0. 002) and agreement (P = 0. 024) . The TLS was not significantly correlated to clinical pathological parameters. The patients with high level of TLS had better prognosis (P = 0. 025) with the mean survival time of 48. 54 months. In multivariate Cox regression analysis, TLS was an independent prognostic factor (P = 0. 031) . Conclusion The pathological evaluation of TLS is accurate. The formation of TLS is an important positive prognostic factor for GC patients.
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Objective To determine whether coagulase-negative non-epidermal staphylococcus is methicillin-resistant coagulase-negative staphylococcus by mecA gene test,when the minimal inhibitory concentration(MIC)of oxacillin is between 0.5-2.0 mg/L.Methods The mecA gene was detected and analyzed by the cefoxitin disk diffusion,E-test,VITEK-2 Compact and polymerase chain reaction (PCR)purification.Results A total of 300 strains of coagulase-negative staphylococci were screened from 4032 patients(7.4％),of which 45 strains of Staphylococcus saprophyticus and 80 strains of Staphylococcus hemolyticus were identified by Compact VITEK-2.There was a statistically significant difference in the positive rate of mecA gene detection between Staphylococcus saprophyticus and Staphylococcus hemolyticus(P ＜0.05).The results of detection of cefoxitin disk diffusion(inhibitory zone diameter ≥ 25 mm),E-test(MIC of oxacillin between 0.5-2.0 mg/L)and Compact VITEK-2 (MIC of oxacillin between 0.5-2.0 mg/L)showed that there were 81 strains of coagulase-negative non-Staphylococci,of which 10 strains with positive mecA gene were confirmed by PCR.Conclusions When the minimal inhibitory concentration (MIC)of oxacillin against coagulase-negative non-Staphylococci stains is between 0.5-2.0 mg/L,the guidelines of the American clinical laboratory standardization institute(CLSI)should be strictly implemented in clinical microbiology laboratory and the mecA gene must be tested.Based on the wide dissemination of the mecA gene in Staphylococcus aureus population,if the mecA gene test is negative,it is reported as methicillin-susceptible coagulase-negative Staphylococcus(MSCNS),and the reverse result is reported as methicillin-resistant coagulase-negative staphylococcus(MRCNS).
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Objective To analyze the antimicrobial resistance, distribution of resistance genes and staphylococcal cassette chromosome mec ( SCCmec) in 99 strains of mecA gene-positive Staphylococcus epi-dermidis strains isolated from early pregnancy cervical swabs and external environment in Beijing Chaoyang District from 2015 to 2016. Methods Kirby-Bauer disk diffusion method was performed to detect the sus-ceptibility of the 99 Staphylococcus epidermidis strains to cefoxitin. Microbroth dilution method was used to test their susceptibility to vancomycin, daptomycin, penicillin, erythromycin, compound sulfamethoxazole, tetracycline, ciprofloxacin, clindamycin, gentamicin and chloramphenicol. PCR was used to detect drug re-sistance genes of ermA, ermB, ermC, msrA, norA1, norA2, sul1, sul2, sul3, aac(6')/aph(2″), ant(4', 4″), ant(6) and tetM and to analyze the SCCmec types ofⅠ, Ⅱ, Ⅲ, Ⅳa, Ⅳb, Ⅳc, Ⅳd and Ⅴ. The results were compared with those of capillary electrophoresis. SPSS was used for data analysis. Results All of the 99 mecA-positive Staphylococcus epidermidis strains were sensitive to vancomycin and 93. 94％ of them were sensitive to datomycin. The resistance rates to penicillin, erythromycin, cefoxitin, compound sulfame-thoxazole, tetracycline, ciprofloxacin, clindamycin, gentamicin and chloramphenicol were 97. 98％, 85. 86％, 79. 80％, 52. 54％, 27. 27％, 43. 43％, 36. 36％, 23. 23％ and 11. 11％. The strains that car-ried the genes of norA1, norA2, ermA, ermB, ermC, msrA, sul1, sul2, sul3, aac(6')/aph(2″), ant(4', 4″), ant(6) and tetM accounted for 100％, 93. 94％, 0. 00％, 3. 03％, 17. 17％, 57. 58％, 50. 51％, 12. 12％, 4. 04％, 30. 30％, 8. 08％, 4. 04％ and 25. 26％, respectively. Among the 99 strains, 5. 05％, 0％, 43. 43％, 10. 10％, 0. 00％, 3. 03％, 3. 03％ and 19. 19％ belonged to SCCmecⅠ, Ⅱ, Ⅲ, Ⅳa,Ⅳb,Ⅳc,Ⅳd andⅤ, respectively, and 4. 04％ (4/99) were positive to two SCCmec types. The types of 12. 12％ (12/99) of the strains were unidentified. Conclusions All of the 99 strains of mecA-positive Staphylococcus epidermidis were sensitive to vancomycin. Among them, the strains carrying multidrug resist-ance genes accounted for 89. 90％. The main mechanisms of resistance to macrolides, sulfonamides and ami-noglycosides in local strains were related to the resistance genes of msrA, sul1 and aac ( 6')/aph ( 2″) . SCCmec Ⅲ was the prevalent type. There were 88. 37％ of SCCmec Ⅲ type strains and 75％ of unknown type strains carrying multiple resistance genes. Apart from that, the isolated strains of other SCCmecⅢtypes all carried multiple resistance genes.
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@#Introduction: Methicillin-resistant Staphylococcus aureus is globally a major public health threat. Resistance to methicillin originates from a modified protein (PBP2a) encoded by the mecA gene. The PVL gene as an important virulence factor increases the pathogenicity of MRSA. Epidemiology and characteristics of MRSA differ in different geographical regions. This study was conducted to characterize and determine the antibiotic susceptibility profile of MRSA strains isolated from patients in Hospital Tengku Ampuan Afzan, Pahang, Malaysia and to detect the presence of the mecA and PVL genes in the isolates. Materials and methods: In this study a total of 36 isolates of MRSA have been collected during a period of three months (1stFebruary –30thApril 2018). The susceptibility pattern of the isolates to ten different commonly used antibiotics were determined and the target genes were addressed by real-time PCR experiment. Results: Based on the identifying criteria, 44.4% of the isolates were CA-MRSA, and 55.5% were HA-MRSA. Resistance to oxacillin, cefoxitin and penicillin was 100%, gentamicin 88.8%, erythromycin 33.3%, tetracycline 77.7%, trimethoprim-sulfamethoxazole 61.1%, clindamycin 13.8%, chloramphenicol 11.1%, but no resistant strain of vancomycin was detected. Most of the isolates were resistant to more than three groups of antibiotics. Realtime PCR revealed that all the isolates were mecA positive and 4 isolates were PVL-positive. PVL-positive strains were CA-MRSA and susceptible to clindamycin. Conclusion: The study confirms multi-drug resistant MRSA in the study area, and shows that resistance to methicillin is mecA mediated. PVL carrier strains were present and related to CA-MRSA strains of the isolates.
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Resumen Introducción: Staphylococcus aureus es un importante patógeno, puede causar infecciones leves de piel, hasta enfermedades con compromiso vital. La aparición de Staphylococcus aureus meticilino-resistentes, MRSA; ha aumentado su resistencia antimicrobiana, especialmente a β-lactámicos; dificultando el manejo de las infecciones, aumentando las tasas de morbi-mortalidad, convirtiéndose en un problema de salud pública. La expresión fenotípica de la resistencia suele ser heterogénea, dificultando su detección en el laboratorio por métodos convencionales; lo cual, incrementa los costos en la atención hospitalaria de infecciones por MRSA. Objetivo: Comparar métodos fenotípico y genotípico para la identificación de aislamientos hospitalarios de MRSA en centros hospitalarios de Pereira. Métodos: A partir de aislamientos de S. aureus obtenidos de tres instituciones de salud de alta complejidad clasificadas como A, B y C; se determinó la resistencia a meticilina por concentración mínima inhibitoria en sistemas automatizados y el gen mecA por PCR múltiple. Resultados: La prevalencia fenotípica de MRSA fue 44,4%, la institución A presentó la mayor tasa con 48,65%. La prevalencia genotípica fue 57,4%; en las instituciones A, B y C fue 55,2%, 41,7% y 75%, respectivamente, con diferencia estadísticamente significativa (p<0.05). La sensibilidad y especificidad del método fenotípico fue 99,0% y 94,7%, respectivamente, frente al método gold estándar de la PCR. El índice Kappa fue 0,942 indicando un nivel de concordancia muy bueno entre métodos. Conclusión: La prevalencia de aislamientos MRSA en las instituciones de Pereira fue alta. Los índices de concordancia de los métodos fenotípicos demostraron que son confiables para el diagnóstico de infecciones por MRSA.
Abstract Introduction: Staphylococcus aureus is an important pathogen, can cause mild skin infections, to diseases with compromise vital. The appearance of Methicillin-Resistant Staphylococcus aureus MRSA; It has increased its antimicrobial resistance, especially to β-lactam; hampering the handling of them infections, increasing the rates of morbidity-mortality, becoming a health public problem. The phenotype expression of the resistance tend to be heterogeneous, hindering its detection in the laboratory by conventional methods; which increases costs in the hospital care of MRSA infections. Objective: To compare the phenotypes and genotypes methods for identification of hospital isolates MRSA in Pereira. Methods: From isolates of S. aureus obtained of three high complexity institutions of health classified as A, B and C; determined resistance to Methicillin by minimum inhibitory concentration in automated systems and mecA gene by multiplex PCR. Results: The phenotype prevalence of MRSA was 44.4%, the institution A presented the highest rate with 48.65%. The genotype prevalence was 57.4%; in the institutions A, B and C was 55.2%, 41.7% and 75%, respectively, with difference statistically significant (p < 0.05). The sensitivity and specificity of the phenotype method were 99.0% and 94.7%, respectively, against the gold standard of the PCR method. The Kappa index was 0,942 indicating a very good level of concordance between methods. Conclusion: The prevalence of isolates MRSA in the institutions of Pereira was high. The concordance index of phenotype methods showed that they are reliable for the diagnosis of MRSA infections.
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Humains , Staphylococcus aureus , Tests de sensibilité microbienne , Réaction de polymérisation en chaîne , Staphylococcus aureus résistant à la méticilline , Méticilline , Coûts et analyse des coûts , Soins Hospitaliers , Réaction de polymérisation en chaine multiplex , Laboratoires , Lactames , MéthodesRÉSUMÉ
No cenário agroindustrial brasileiro a cadeia suinícola vem se destacando cada vez mais. A inserção no mercado internacional e as novas tecnologias aplicadas na prática de produção de suínos tem grande importância na economia do país. No entanto, algumas bactérias oportunistas estão presentes nas regiões nasais de suínos, sendo responsáveis por diversas alterações clínicas na suinocultura. Um dos principais patógenos que acomete esta espécie é o Staphylococcus aureus, responsável também por infeções nos seres humanos. O S. aureus possui características de virulência e resistência a diversos antibióticos, em especial à oxacilina, um antibiótico pertencente ao grupo ß-lactâmicos com ampla escala de utilização. A resistência do S. aureus à oxacilina está interligada a vários fatores, como a presença do gene mecA, que codifica a produção de uma proteína ligante e, assim, diminui a afinidade e a sensibilidade à ação de compostos antimicrobianos ß-lactâmicos. O uso errôneo de antibióticos é um dos fatores responsáveis por cepas resistentes e, a adição de melhoradores de desempenho nas rações de suínos, com a adição de antibióticos de forma preventiva pode favorecer e aumentar a existência de cepas multirresistentes, agravando ainda mais os dados já obtidos em pesquisas. A seleção destes genes resistentes causa preocupação à saúde coletiva, uma vez que indivíduos que tiveram contato com suínos e moradores residentes próximos as granjas apresentam cepas resistentes de S. aureus. Assim, a utilização de antibióticos de forma correta é fundamental para a redução dos índices de resistências à antibióticos..
Pig farming has been increasingly prominent in the Brazilian agroindustrial scenario. Its insertion in the international market and the use of new technologies applied to pig farming have been of great importance to the country's economy. Nevertheless, opportunistic bacteria present in the nasal regions of pigs are responsible for several clinical changes in the breeding of those animals. Staphylococcus aureus features among the main pathogens affecting that species, being also responsible for infections in humans. S. aureus is characterized by its virulence and resistance to several antibiotics, especially oxacillin, an antibiotic belonging to the ß-lactam group with a wide usage range. The resistance of S. aureus to oxacillin is linked to several factors, such as the presence of the mecA gene, which encodes the production of a binding protein and thus decreases the affinity and sensitivity to the action of ß-lactam antimicrobial compounds. Incorrect use of antibiotics is one of the factors responsible for generating resistant strains, and the addition of growth promoters in pig feeds with the addition of antibiotics as a form of prevention may favor and even increase the existence of multiresistant strains, further aggravating the current scenario, as expressed by data already obtained in research. The selection of these resistant genes is a matter of concern for collective health, since individuals that had contact with pigs and residents living near pig farms present S. aureus resistant strains. Thus, the correct use of antibiotics is pivotal for reducing the antibiotic resistance rates.
En el escenario agroindustrial brasileño la cadena porcina viene destacándose cada vez más. La inserción en el mercado internacional y las nuevas tecnologías aplicadas en la práctica de producción de cerdos, tiene gran importancia en la economía del país. Sin embargo, algunas bacterias oportunistas están presentes en las regiones nasales de cerdos, siendo responsables por diversas alteraciones clínicas en la porcicultura. Uno de los principales patógenos que acomete esta especie es el Staphylococcus aureus, responsable también por infecciones en los seres humanos. El S. aureus posee características de virulencia y resistencia a diversos antibióticos, en especial a la oxacilina, un antibiótico perteneciente al grupo ß-lactámicos con amplia escala de utilización. La resistencia del S. aureus a oxacilina está interconectada a varios factores, como la presencia del gen mecA, que codifica la producción de una proteína ligante y así disminuye la afinidad y la sensibilidad a la acción de compuestos antimicrobianos ß-lactámicos. El uso erróneo de antibióticos es uno de los factores responsables de cepas resistentes y, la adición de promotores de crecimiento en las raciones de cerdos, con la adición de antibióticos de forma preventiva, puede favorecer y aumentar la existencia de cepas multirresistentes, agravando aún más los datos ya obtenidos en investigaciones. La selección de estos genes resistentes causa preocupación a la salud colectiva, ya que individuos que tuvieron contacto con cerdos y residen cercano a las granjas presentan cepas resistentes de S. aureus. Así, la utilización de antibióticos de forma correcta es fundamental para la reducción de índices de resistencias a los antibióticos.
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Animaux , Staphylococcus aureus/immunologie , Suidae/microbiologie , Anti-infectieux/immunologie , AntibactériensRÉSUMÉ
Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) being a constant concern, ceftaroline fosamil has been recently approved as a new cephalosporin, active against MRSA, for use in humans; only rare cases of resistance have been reported till date. There is no report of resistance to ceftaroline in Staphylococcus pseudintermedius, which is the main bacterium causing dermatitis and otitis in dogs. To evaluate staphylococcal resistance to ceftaroline, 35 isolates of methicillin-resistant S. pseudintermedius (MRSP), carrying the mecA gene, from 26 dogs with folliculitis and nine dogs with external otitis, underwent disk diffusion test with cefoxitin, oxacillin, and ceftaroline. Tests with cefoxitin and oxacillin showed > 90% sensitivity in methicillin resistance detection. In the disk diffusion test, 97.14% (34/35) were resistant to cefoxitin, 94.29% (33/35) to oxacillin, and 31.43% (11/35) to ceftaroline. Of the ceftaroline-resistant strains, 27.27% (3/11) were obtained from the ears of dogs while the rest (8/11) were from the skin. The current report is the first description of MRSP resistance to ceftaroline.(AU)
Infecções causadas por Staphylococcus aureus resistente à meticilina (MRSA) são uma preocupação médica constante. A ceftarolina fosamila é uma nova cefalosporina ativa contra Staphylococcus aureus resistente à meticilina recentemente aprovada para uso em humanos e raros casos de resistência relatados até agora. Não há relatos de resistência à ceftarolina em Staphylococcus pseudintermedius, principal bactéria causadora de dermatite e otite em cães. Com o objetivo de avaliar a resistência estafilocócica à ceftarolina, 35 amostras de S. pseudintermedius resistentes à meticilina (MRSP), portadoras do gene mecA, provenientes de 26 cães com foliculite e 9 com otite externa foram submetidos ao teste de disco-difusão com cefoxitina, oxacilina e ceftarolina. Os testes realizados com cefoxitina e oxacilina mostraram mais de 90% de sensibilidade na detecção da resistência à meticilina em ambas. No teste da disco-difusão, 97,14% (1/35) foram resistentes à cefoxitina, 94,29% (3/35) à oxacilina e 31,43% (11/35) à ceftarolina. Das cepas resistentes às ceftarolina, 27,27 (3/11) foram provenientes de ouvido de cães e as demais (8/11), provenientes da pele, sendo essa primeira descrição de resistência de MRSP à ceftarolina na literatura atual.(AU)
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Animaux , Chiens , Oxacilline , Staphylococcus/génétique , Staphylococcus aureus , Infections cutanées à staphylocoques/médecine vétérinaire , Céfoxitine , Résistance aux céphalosporines , Chiens/microbiologie , Dermatite/médecine vétérinaire , Tests d'agents antimicrobiens par diffusion à partir de disques/médecine vétérinaire , Folliculite/médecine vétérinaireRÉSUMÉ
Background: Reservoir of methicillin resistance genes called staphylococcal cassette chromosome mec (SCCmec), plasmids and genomic characterisations of isolates have been widely investigated in epidemiologic research. However, the extent to which these organisms are transported by patients or hospital staff is not entirely clear. Aim: This study aims to investigate the molecular relatedness and plasmid profiles of MR staphylococci isolated from nursing students before and after hospital training, to find out the possible source. Materials and Methods: This study examined 39 methicillin-resistant (MR) staphylococci and 2 inducible clindamycin-resistant, methicillin-susceptible Staphylococcus aureus. Specimens were collected before and after 4 months of hospital training from the hands and nares of 75 nursing students. A polymerase chain reaction technique was used to confirm the existence of mecA gene and identify SCCmec types; total DNA was digested by SmaI endonuclease restriction to monitorise clonal relatedness by pulsed-field gel electrophoresis (PFGE); plasmid profiles were monitorised on agarose gel. Results: All 39 isolates tested positive for mecA; SCCmec type III was observed most frequently. Interestingly, in one isolate of Staphylococcus epidermidis, four different types of SCCmec elements were observed. There were 23 different types of plasmids, whose sizes ranged from 1.4 to 46.0 kb. After PFGE dendogram analysis, two strains were classified as indistinguishable; six were closely related. Most of the isolates obtained after hospital training showed clonal similarity and seven had multiple SCCmec elements require further investigation for the possible mechanism. Conclusion: Most of the isolates obtained after hospital training showed clonal similarity and seven had multiple SCCmec elements require further investigation for the possible mechanism.
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ABSTRACT Introduction: Staphylococcus spp. - both S. aureus, including methicillin-resistant strains (MRSA) and coagulase negative staphylococci (CoNS) - are relevant agents of healthcare-associated infections. Therefore, the rapid recognition of MRSA and methicillin-resistant CoNS from blood stream infections is critically important for patient management. It is worth noting that inappropriate empiric therapy has been associated with higher in-hospital mortality. Material and methods: In this study we evaluated a multiplex polymerase chain reaction (multiplex PCR) standardized to detect Staphylococcus spp., S. aureus, and mecA gene-encoded oxacillin resistance directly from blood culture bottles. A total of 371 blood cultures with Gram-positive microorganisms confirmed by Gram-stain were analyzed. Results from multiplex PCR were compared to phenotypic characterization of isolates. Results: Staphylococcus aureus was detected in 85 (23.0%) blood cultures and CoNS in 286 (77.0%). There was 100% agreement between phenotypic and multiplex PCR identification. Forty-three (50.6%) of the 85 S. aureus carried the mecA gene and among the 286 CoNS, 225 (78.7%) were positive for the mecA gene. Conclusions: The multiplex PCR assay developed here was found to be sensitive, specific, rapid, and showed good agreement with the phenotypic results besides being less expensive. This PCR method could be used in clinical laboratories for rapid identification and initiation of specific and effective treatment, reducing patient mortality and morbidity. Furthermore, this method may reduce misuse of antimicrobial classes that are more expensive and toxic, thus contributing to the selection of antibiotic-resistant Staphylococcus spp.