RESUMO
Abstract This study was undertaken to investígate the resistance phenotypes to macrolide-lincosamide-streptogramin B (MLSb) antibiotics and their associated genotypes in isolates of Staphylococcus aureus. We analyzed one hundred, consecutive, non-duplicate isolates (methicillin-susceptible MSSA, n = 53 and methicillin-resistant MRSA, n =47) obtained from var-ious clinical samples between July 2012 to December 2013. The resistance profile to MLSb antibiotics was determined by phenotypic methods and the resistance genes were detected by PCR assays. All of the isolates were subjected to pulsed-field gel electrophoresis (SmaI-PFGE). The overall prevalence of resistance to MLSb antibiotics was 38% and the resistance phenotype distribution was as follows: cMLSb, 22%; iMLSB, 10%; MSb, 5% and L, 1%. We detected ermA, ermC, ermB and mrsA/B genes in these resistant isolates. The single ermA gene was commonly observed mainly in those with a cMLSb R phenotype, whereas the combination ermA and ermC was more commonly observed in isolates with inducible expression. The patterns of SmaI-PFGE suggest a great genetic diversity in both MRSA and MSSA resistant to MLSb antibiotics. The results demonstrate the local presence of S. aureus resistant to MLSb antibiotics and its most frequently described responsible genes. Some of these isolates, especially those with the iMLSB phenotype, may be associated with therapeutic failure. Therefore, efforts should be directed to the correct detection of all MLSb resistant isolates using appropriate laboratory tests. PFGE results reveal a wide spread of resistance genes rather than the circulation of S. aureus clones resistant to MLSb antibiotics.
Resumen Los objetivos de este estudio fueron investigar en Staphylococcus aureus la presencia de fenotipos resistentes a los antibióticos macrólidos, lincosamidas y estreptograminas tipoB (MLSb) y conocer sus genotipos responsables. Analizamos 100 aislamientos consecutivos, no duplicados (53 sensibles a meticilina [MSSA] y 47 resistentes a meticilina [MRSA]), obtenidos entre 2012 y 2013 a partir de diferentes muestras clínicas. El perfil de resistencia a los antibióticos MLSb fue determinado por métodos fenotípicos y los genes de resistencia se detectaron por PCR. Todos los aislamientos fueron comparados por SmaI-PFGE. La prevalencia global de resistencia a los antibióticos MLSB fue del 38% y la distribución de los fenotipos de resistencia fue la siguiente: cMLSB, 22%; iMLSB, 10%; MSB, 5%; L, 1%. Se detectaron los genes ermA, ermC y mrsA/B en los aislamientos resistentes. El gen ermA se observó, sobre todo, en aislamientos con fenotipo resistente constitutivo R (cMLSB), mientras que la combinación ermA y ermC se detectó principalmente en aislamientos con resistencia inducible (iMLSB). Los patrones de Smal-PFGE sugieren una gran diversidad genética en los aislamientos resistentes a los antibióticos MLSb, tanto MRSA como MSSA. Los resultados demuestran la presencia local de S. aureus resistentes a los antibióticos MLSB y de sus genes responsables más frecuentemente descritos. Estos cultivos, especialmente aquellos con fenotipo resistente iMLSB, pueden asociarse con fallas terapéuticas. Por lo tanto, los esfuerzos deben dirigirse a la correcta detección de todos los cultivos resistentes a MLSB utilizando pruebas de laboratorio adecuadas. Los resultados de Smal-PFGE sugieren una amplia diseminación de genes de resistencia, más que la circulación de clones resistentes a los antibióticos MLSB.
Assuntos
Humanos , Infecções Estafilocócicas , Farmacorresistência Bacteriana Múltipla , Staphylococcus aureus Resistente à Meticilina , Fenótipo , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/genética , Uruguai , Testes de Sensibilidade Microbiana , Macrolídeos/farmacologia , Estreptogramina B/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Staphylococcus aureus Resistente à Meticilina/genética , Lincosamidas/farmacologia , Centros de Atenção Terciária , Genótipo , Hospitais Públicos , Antibacterianos/farmacologiaRESUMO
The aim of this work was to determine the susceptibility, molecular profile, and clonal relationship in Streptococcus agalactiae (group B Streptococcus [GBS]) isolated from vaginal-rectal swab samples. We worked with 200 isolates collected from pregnant women between 35 and 37 weeks of gestation. The macrolide-lincosamide-streptogramin B (MLSB) resistance phenotypes were determined using the double-disc assay. Susceptibility to erythromycin (ERI) and clindamycin (CLI) was performed with the E-test. Resistance genes ermB and ermTR were detected by polymerase chain reaction. Clonal studies were performed using the random amplification of polymorphic DNA. Twelve (6%) of the isolates were resistant to ERI and 10 (5%) of them to CLI. Fifty percent of the resistant strains corresponded to serotype III, 25% to serotype V, and the remaining 25% to serotype Ia, II, and nontypeable strains. The cMLSB phenotype was detected in eight strains (66.67%) and the iMLSB phenotype in four (33.33%). The minimum inhibitory concentration values were between 1.5 and 16 µg/mL for ERI, and between 1 and 32 µg/mL for CLI. Out of the 25 strains susceptible to ERI and CLI, the presence of the ermB gene was detected in eight of them and the ermTR gene in one strain. The ermB gene was detected in the 12 strains that initially had some macrolide resistance phenotype. The ermTR gene was detected in three out of the four strains with the iMLSB phenotype. The resistance to macrolides in the province of Misiones is due to multiclonal spread. The phenotypic and genotypic characterization of macrolide resistance in GBS strains are crucial to contribute to the correct intrapartum prophylactic antibiotic therapy of allergic pregnant women and the epidemiological surveillance of these strains.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Streptococcus agalactiae/genética , Argentina , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Feminino , Genótipo , Idade Gestacional , Humanos , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , Gravidez , Terceiro Trimestre da Gravidez , Streptococcus agalactiae/efeitos dos fármacosRESUMO
This study was undertaken to investigate the resistance phenotypes to macrolide-lincosamide-streptogramin B (MLSB) antibiotics and their associated genotypes in isolates of Staphylococcus aureus. We analyzed one hundred, consecutive, non-duplicate isolates (methicillin-susceptible MSSA, n=53 and methicillin-resistant MRSA, n=47) obtained from various clinical samples between July 2012 to December 2013. The resistance profile to MLSB antibiotics was determined by phenotypic methods and the resistance genes were detected by PCR assays. All of the isolates were subjected to pulsed-field gel electrophoresis (SmaI-PFGE). The overall prevalence of resistance to MLSB antibiotics was 38% and the resistance phenotype distribution was as follows: cMLSB, 22%; iMLSB, 10%; MSB, 5% and L, 1%. We detected ermA, ermC, ermB and mrsA/B genes in these resistant isolates. The single ermA gene was commonly observed mainly in those with a cMLSB R phenotype, whereas the combination ermA and ermC was more commonly observed in isolates with inducible expression. The patterns of SmaI-PFGE suggest a great genetic diversity in both MRSA and MSSA resistant to MLSB antibiotics. The results demonstrate the local presence of S. aureus resistant to MLSB antibiotics and its most frequently described responsible genes. Some of these isolates, especially those with the iMLSB phenotype, may be associated with therapeutic failure. Therefore, efforts should be directed to the correct detection of all MLSB resistant isolates using appropriate laboratory tests. PFGE results reveal a wide spread of resistance genes rather than the circulation of S. aureus clones resistant to MLSB antibiotics.
Assuntos
Farmacorresistência Bacteriana Múltipla , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Genótipo , Hospitais Públicos , Humanos , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Fenótipo , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/genética , Estreptogramina B/farmacologia , Centros de Atenção Terciária , UruguaiRESUMO
BACKGROUND: Streptococcus agalactiae or Group B Streptococcus (GBS) remains the leading cause of infections in newborns worldwilde. Prenatal GBS screening of pregnant women for vaginal-rectal colonization is recommended in many countries to manage appropriate intrapartum antimicrobial prophylaxis for those identified as carriers. In this study, a novel melting-curve based multiplex real-time PCR assay for the simultaneous detection of GBS and macrolide and lincosamide resistance markers was developed. The usefulness of the assay was evaluated for rapid and accurate prenatal GBS screening. METHODS: One hundred two pregnant women who were at 35-37 weeks of gestation were enrolled in this study. The analytical performance of the multiplex real-time PCR was first tested using a panel of reference and clinical bacterial and fungal strains. To test the clinical performance, vaginal-rectal swabs were obtained from pregnant women who were seen at the teaching hospital for regular prenatal care. The results of real-time were compared with those obtained from microbiological analyses. RESULTS: The real-time PCR assay showed 100% specificity and a limit of detection of 104 colony forming units equivalent per reaction. The prevalence of GBS colonization among the population studied was 15.7% (16/102) based on a positive culture and the real-time PCR results. Agreement between the two assays was found for 11 (68.75%) GBS colonized women. Using the culture-based results as a reference, the multiplex real-time PCR had a sensitivity of 91.7% (11/12, CI 59.7-99.6%), a specificity of 95.5% (86/90, CI 89.8-98.7%), a positive predictive value of 73.3% (11/15, CI 44.8-91.1%) and a negative predictive value of 98.9% (86/87, CI 92.9-99.9%). CONCLUSION: The multiplex real-time PCR is a rapid, affordable and sensitive assay for direct detection of GBS in vaginal-rectal swabs.
Assuntos
Portador Sadio/diagnóstico , Farmacorresistência Bacteriana/genética , Diagnóstico Pré-Natal/métodos , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/isolamento & purificação , Proteínas de Bactérias/genética , Feminino , Humanos , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Proteínas de Membrana/genética , Metiltransferases/genética , Reação em Cadeia da Polimerase Multiplex/métodos , Valor Preditivo dos Testes , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reto/microbiologia , Streptococcus agalactiae/genética , Vagina/microbiologiaRESUMO
INTRODUCTION: Bovine mastitis causes important economic losses in the dairy industry. Coagulase-negative staphylococci (CNS) are a group of bacteria commonly isolated from bovine mastitis and can display resistance to a wide range of antimicrobial agents. OBJECTIVES: The objective of this study was to determine staphylococcal resistance towards ß-lactam, macrolide and lincosamide antimicrobials in quarters previously treated with third-generation cephalosporin and after lincosamide intramammary therapy. METHODS: Sick quarters of eighteen cows from Villaguay, Entre Ríos (Argentina) with clinical mastitis were studied. All staphylococcal isolates were tested by disk diffusion for their antimicrobial susceptibilities. Cefoxitin resistance was investigated by PCR and sequencing for both the mecA and mecC genes. RESULTS: Resistances to penicillin, oxacillin and cefoxitin were observed, whereas no resistance to macrolide and lincosamide was detected. A cefoxitin-resistant Staphylococcus saprophyticus was found to be mecA-negative but mecC-positive. CONCLUSIONS: This study reports for the first time the mecC gene from a CNS in bovine mastitis in South America. Because CNS may act as reservoirs of antimicrobial resistance genes, they can be seen as a potential public health threat with respect to antimicrobial resistance and the development of multiple resistance. Also, the emergence of methicillin-resistant phenotypes will limit therapeutic options.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Mastite Bovina/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus saprophyticus/isolamento & purificação , Animais , Argentina , Bovinos , Cefoxitina/farmacologia , Feminino , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Testes de Sensibilidade Microbiana , Análise de Sequência de DNA , Staphylococcus saprophyticus/efeitos dos fármacos , Staphylococcus saprophyticus/genética , beta-Lactamas/farmacologiaRESUMO
BACKGROUND: Bacterial vaginosis (BV) is an infection that has a prevalence between 10% to 50% worlwide. BV results in an imbalance of the normal vaginal flora. Microorganisms associated with BV have been isolated from the normal flora of the male genital tract, and their presence could be related to the recurrence of BV after antibiotic treatment. Therefore, the treatment of sexual partners could decrease the recurrence of infection and possibly the burden of the disease. OBJECTIVES: To assess the effectiveness in women and the safety in men of concurrent antibiotic treatment for the sexual partners of women treated for BV. SEARCH METHODS: We searched the Cochrane Sexually Transmitted Infections Group Specialized Register (23 July 2016), CENTRAL (1991 to 23 July 2016), MEDLINE (1946 to 23 July 2016), Embase (1974 to 23 July 2016), LILACS (1982 to 23 July 2016), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (23 July 2016), ClinicalTrials.gov (23 July 2016) and the Web of Science™ (2001 to 23 July 2016). We also handsearched conference proceedings, contacted trial authors and reviewed the reference lists of retrieved studies. SELECTION CRITERIA: Randomized controlled trials (RCTs) that compared the concurrent use of any antibiotic treatment with placebo, no intervention or any other intervention by the sexual partners of women treated for BV. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trials for inclusion, extracted data and assessed the risk of bias in the included studies. We resolved any disagreements through consensus. We assessed the quality of the evidence using the GRADE approach. MAIN RESULTS: Seven RCTs (1026 participants) met our inclusion criteria, and pharmaceutical industry funded four of these trials. Five trials (854 patients) compared any antibiotic treatment of sexual partners with placebo. Based on high quality evidence, antibiotic treatment does not increase the rate of clinical or symptomatic improvement in women during the first week (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.96 to 1.03; 712 participants, four studies; RR 1.06, 95% CI 1.00 to 1.12; 577 patients, three studies, respectively), between the first and fourth week (RR 1.02, 95% CI 0.94 to 1.11; 590 participants, three studies; RR 0.93, 95% CI 0.84 to 1.03; 444 participants, two studies; respectively) or after the fourth week (RR 0.98, 95% CI 0.90 to 1.07; 572 participants, four studies; RR 1.03, 95% CI 0.90 to 1.17; 296 participants, two studies; respectively). Antibiotic treatment does not led to a lower recurrence during the first and fourth week (RR 1.28, 95% CI 0.68 to 2.43; 218 participants, one study; low quality evidence) or after the fourth week of treatment (RR 1.00, 95% CI 0.67 to 1.52; 372 participants, three studies; low quality evidence) in women, but increases the frequency of adverse events (most frequently gastrointestinal symptoms) reported by sexual partners (RR 2.55, 95% CI 1.55 to 4.18; 477 participants, three studies; low quality evidence). Two trials (172 participants) compared any antibiotic treatment for sexual partners with no intervention. When we compared it with no intervention, the effects of antibiotic treatment on recurrence rate after the fourth week (RR 1.71, 95% CI 0.65 to 4.55; 51 participants, one study), clinical improvement between the first and fourth week (RR 0.93, 95% CI 0.70 to 1.25; 152 participants, two studies) and symptomatic improvement after the fourth week (RR 0.66, 95% CI 0.39 to 1.11; 70 participants, one study) were imprecise and there were no differences between groups. We downgraded the quality of the evidence to low or very low. AUTHORS' CONCLUSIONS: High quality evidence shows that antibiotic treatment for sexual partners of women with BV, compared with placebo, does not increase the rate of clinical or symptomatic improvement during the first, between the first and fourth or after the fourth week into the women. Low quality evidence suggests that antibiotic treatment does not led to a lower recurrence rate during the first and fourth or after the fourth week of treatment into the women, but increases the frequency of adverse events reported by sexual partners. Finally, compared with no intervention, antibiotic treatment does not decrease the recurrence rate after the fourth week and does not increase the frequency of clinical or symptomatic improvement between the first and fourth or after the fourth week into the women, respectively.
Assuntos
Antibacterianos/uso terapêutico , Prevenção Secundária , Parceiros Sexuais , Vaginose Bacteriana/prevenção & controle , Adolescente , Adulto , Antibacterianos/efeitos adversos , Clindamicina/uso terapêutico , Feminino , Humanos , Indazóis/uso terapêutico , Lincosamidas/uso terapêutico , Masculino , Metronidazol/uso terapêutico , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Recidiva , Fatores de Tempo , Tinidazol/uso terapêuticoRESUMO
Staphylococcus aureus can cause a variety of infections due to its high transmissibility, high pathogenic potential and resistance to multiple drugs, factors that contribute to the relevance of infections in healthcare services. The aim of this study was to document phenotypic and genotypic resistance factors of Staphylococcus aureus strains, isolated from nasal mucosa of medical students. A nasal swab was collected from the nares (nostrils) of 222 medical students. After collection, the samples were submitted to isolation and identification procedures. From 204 valid samples, 20.6% (42 samples) were positive for S. aureus. For the assessment of phenotypic resistance by disk-diffusion technique, from 42 samples, 95.2% showed resistance to erythromycin, 42.8% to clindamycin, 16.6% to cephoxitin and 9.5% to oxacillin. The D test showed that 26.2% of samples were resistant to macrolides, lincosamides and streptogramin B. A PCR assay allowed for the evaluation of a genotypic resistance profile, in which 16.6% of the samples were positive for the mecA gene, 35.7% positive for the ermC gene or ermA gene and 28.5% were positive for both genes. These results demonstrate that medical students can enter the healthcare service previously colonized by multidrug resistant strains and become potential spreaders in the hospital environment.
Assuntos
Portador Sadio/microbiologia , Farmacorresistência Bacteriana , Nariz/microbiologia , Staphylococcus aureus/isolamento & purificação , Estudantes de Medicina , Antibacterianos/farmacologia , Humanos , Lincosamidas/farmacologia , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Estreptogramina B/farmacologiaRESUMO
Introducción: las infecciones por S. aureus meticilino resistentes son un problema de salud pública por el perfil de multirresistencia que presenta este patógeno. Objetivo: determinar el fenotipo de resistencia a meticilina, macrólidos y lincosamidas en cepas de S. aureus. Materiales y métodos: se analizaron 50 cepas de S. aureus aisladas de muestras clínicas de pacientes del Hospital Rosario Pumarejo de López en la ciudad de Valledupar. Las pruebas de susceptibilidad a meticilina, eritromicina y clindamicina se realizaron por los métodos microdilución en caldo y difusión en agar. Se determinó la resistencia a meticilina mediante la técnica agar dilución y la resistencia inducible a clindamicina, con la prueba del D-Test. Resultados: la resistencia a meticilina fue del 50%, se evidenciaron cinco fenotipos en los macrólidos y lincosamidas analizados: el fenotipo con sensibilidad a eritromicina y clindamicina (78%), fenotipo con resistencia a eritromicina y clindamicina (16%), que presentan resistencia constitutiva para ambos antimicrobianos MLSBc, liderando los fenotipos de resistencia; el fenotipo con sensibilidad intermedia a ambos antimicrobianos (2%), el fenotipo con resultado intermedio para eritromicina y sensibilidad a clindamicina (2%) y el fenotipo con resistencia a eritromicina y sensibilidad a clindamicina (2%), que presentan resistencia inducible a clindamicina MLSBi, con prueba test D positiva. Conclusiones: la resistencia inducible para macrólidos, lincosamidas y streptograminas no se detecta usando los test de susceptibilidad antimicrobiana estándar. La no identificación de esta resistencia inducible puede conducir a falla del tratamiento con clindamicina.
Introduction: Infections with methicillin-resistant S. aureus are a public health problem due to the multi-resistance profile presented by this pathogen. Objective: To determine resistance phenotypes to methicillin, macrolides and lincosamides in S. aureus. Materials and methods: 50 S. aureus strains, isolated from patients of the Hospital Rosario Lopez Pumarejo in the city of Valledupar, were analyzed. Susceptibility tests to methicillin, erythromycin and clindamycin were performed using microdilution and agar diffusion methods. Methicillin resistance was determined through agar dilution technique and inducible clindamycin resistance D-Test. Results: Methicillin resistance reached 50%, five phenotypes were established in the analyzed macrolides and lincosamides: phenotype sensitive to erythromycin and clindamycin (78%); phenotype resistant to erythromycin and clindamycin (16%) with constitutive resistance for both cMLSB antimicrobials, which lead the resistance phenotypes; phenotype with intermediate resistance to both antimicrobials (2%); the intermediate result phenotype resistant to erythromycin and clindamycin (2%); and the RS phenotype resistant to erythromycin and sensitive to clindamycin (2%) that show inducible iMLSB clindamycin resistance with positive D test. Conclusions: The inducible resistance to macrolides, lincosamides and streptogramines is not established through the standard antimicrobial susceptibility test. Not identifying the inducible resistance can lead to clindamycin treatment failure.
Introdução: As infeções por S. aureus meticilino resistentes são um problema de saúde pública pelo perfil de multirresistência que apresenta este patógeno. Objetivo: Determinar o fenótipo de resistência à meticilina, macrolídeos e lincosamidad em cepas de S. aureus. Materiais e métodos: Analisaram-se 50 cepas de S. aureus isoladas de amostras clínicas de pacientes do Hospital Rosario Pumarejo de López na cidade de Valledupar, Colômbia. A susceptibilidade à meticilina, eritromicina e clindamicina se realizaram pelos métodos microdiluição em caldo e difusão em ágar. Determinou-se a resistência à meticilina mediante a técnica ágar diluição e a resistência induzível a clindamicina, com a prova D-Test. Resultados: A resistência a meticilina foi de 50%, se evidenciaram cinco fenótipos nos macrolídeos e lincosamidas analisados: o fenótipo com sensibilidade à eritromicina e clindamicina (78%), fenótipo com resistência à eritromicina e clindamicina (16%), que apresentam resistência constitutiva para ambos os antimicrobianos MLSBc, liderando os fenótipos de resistência; o fenótipo com sensibilidade intermedia a ambos os antimicrobianos (2%), o fenótipo com resultado intermédio para a eritromicina e sensibilidade à clindamicina (2%) e o fenótipo com resistência a eritromicina e sensibilidade à clindamicina (2%), que apresentam resistência induzível à clindamicina MLSBi, com prova test D positiva. Conclusões: A resistência induzível para macrolídeos, lincosamidas e streptograminas não se detecta usando os testes de susceptibilidade antimicrobiana standard. A não identificação desta resistência induzível pode conduzir à falha do tratamento com clindamicina.
Assuntos
Humanos , Farmacorresistência Bacteriana , Staphylococcus aureus , Saúde Pública , Resistência a Meticilina , Colômbia , LincosamidasRESUMO
Abstract Introduction There is a mechanism of macrolide resistance in Staphylococcus spp. which also affects the lincosamides and type B streptogramins characterizing the so-called MLSB resistance, whose expression can be constitutive (cMLSB) or inducible (iMLSB) and is encoded mainly by ermA and ermC genes. The cMLSB resistance is easily detected by susceptibility testing used in the laboratory routine, but iMLSB resistance is not. Therapy with clindamycin in cases of infection with isolated iMLSB resistance may fail. Objective To characterize the phenotypic (occurrence of cMLSB and iMLSB phenotypes) and molecular (occurrence of ermA and ermC genes) profiles of MLSB resistance of clinical isolates of susceptible and methicillin-resistant Staphylococcus aureus and CNS (coagulase-negative Staphylococcus) from patients of a university hospital, in Pernambuco. Methods The antimicrobial susceptibility of 103 isolates was determined by the disk diffusion technique in Mueller–Hinton agar followed by oxacillin screening. The iMLSB phenotype was detected by D test. Isolates with cMLSB and iMLSB phenotypes were subjected to polymerase chain reaction (PCR) for the detection of ermA and ermC genes. Results The cMLSB and iMLSB phenotypes were respectively identified in 39 (37.9%) and five (4.9%) isolates. The iMLSB phenotype was found only in four (10.8%) methicillin-susceptible S. aureus and one (4.5%) methicillin-resistant S. aureus. In the 44 isolates subjected to PCR, four (9.1%) only ermA gene was detected, a lower frequency when compared to only ermC 17 (38.6%) gene and to one (2.3%) isolate presenting both genes. Conclusion In the Staphylococcus spp. analyzed, the ermC gene was found more often than the ermA, although the iMLSB phenotype had been less frequent than the cMLSB. It was important to perform the D test for its detection to guide therapeutic approaches.
Assuntos
Humanos , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Macrolídeos/farmacologia , Estreptogramina B/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Lincosamidas/farmacologia , Fenótipo , Brasil , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Genes Bacterianos/genética , Hospitais UniversitáriosRESUMO
Methicillin-resistant Staphylococcus aureus (MRSA) carrying SCCmec type IV has emerged in hospitals worldwide. The aim of this study was to evaluate phenotypic and molecular characteristics of antimicrobial resistance in MRSA SCCmec IV isolates, presenting different genetic backgrounds, isolated from hospitals in Rio de Janeiro. The antimicrobial resistance of 128 S. aureus type IV isolates from 11 hospitals was characterized by the disk diffusion test and minimum inhibitory concentration (MIC) test. Mutations in parC gene, which encodes ciprofloxacin resistance, and genes associated with macrolide-lincosamide-streptogramin B (MLSb) resistance were also investigated. MRSA isolates belonging to USA400/ST1 (60 isolates), USA800/ST5 (40), USA1100/ST30 (13), and other 11 (15) lineages were mainly resistant to erythromycin (68%), ciprofloxacin (56%), and clindamycin (50%). The highest antimicrobial resistance rates were found among USA400 isolates (p < 0.05). The majority of them (90%) carried only the erm(C) gene and mainly presented two mutation types in the parC gene. The msr(A) gene was most frequently found among USA800 isolates (p < 0.05). Among MRSA type IV isolates from Rio de Janeiro hospitals, multiresistance, including mutations in parC gene, was associated to the USA400/ST1, while the msr(A) gene was associated with USA800/ST5 isolates, highlighting that these lineages could have more potential to persist in a hospital environment.
Assuntos
DNA Topoisomerase IV/genética , Farmacorresistência Bacteriana Múltipla/genética , Regulação Bacteriana da Expressão Gênica , Staphylococcus aureus Resistente à Meticilina/genética , Metionina Sulfóxido Redutases/genética , Metiltransferases/genética , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Brasil/epidemiologia , DNA Topoisomerase IV/metabolismo , Hospitais , Humanos , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Metionina Sulfóxido Redutases/metabolismo , Metiltransferases/metabolismo , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Mutação , Quinolonas/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Estreptogramina B/farmacologiaRESUMO
INTRODUCTION: There is a mechanism of macrolide resistance in Staphylococcus spp. which also affects the lincosamides and type B streptogramins characterizing the so-called MLSB resistance, whose expression can be constitutive (cMLSB) or inducible (iMLSB) and is encoded mainly by ermA and ermC genes. The cMLSB resistance is easily detected by susceptibility testing used in the laboratory routine, but iMLSB resistance is not. Therapy with clindamycin in cases of infection with isolated iMLSB resistance may fail. OBJECTIVE: To characterize the phenotypic (occurrence of cMLSB and iMLSB phenotypes) and molecular (occurrence of ermA and ermC genes) profiles of MLSB resistance of clinical isolates of susceptible and methicillin-resistant Staphylococcus aureus and CNS (coagulase-negative Staphylococcus) from patients of a university hospital, in Pernambuco. METHODS: The antimicrobial susceptibility of 103 isolates was determined by the disk diffusion technique in Mueller-Hinton agar followed by oxacillin screening. The iMLSB phenotype was detected by D test. Isolates with cMLSB and iMLSB phenotypes were subjected to polymerase chain reaction (PCR) for the detection of ermA and ermC genes. RESULTS: The cMLSB and iMLSB phenotypes were respectively identified in 39 (37.9%) and five (4.9%) isolates. The iMLSB phenotype was found only in four (10.8%) methicillin-susceptible S. aureus and one (4.5%) methicillin-resistant S. aureus. In the 44 isolates subjected to PCR, four (9.1%) only ermA gene was detected, a lower frequency when compared to only ermC 17 (38.6%) gene and to one (2.3%) isolate presenting both genes. CONCLUSION: In the Staphylococcus spp. analyzed, the ermC gene was found more often than the ermA, although the iMLSB phenotype had been less frequent than the cMLSB. It was important to perform the D test for its detection to guide therapeutic approaches.
Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética , Estreptogramina B/farmacologia , Brasil , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Genes Bacterianos/genética , Hospitais Universitários , Humanos , FenótipoRESUMO
Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, can be regarded as potential reservoirs of resistance genes for pathogenic strains, e.g., Staphylococcus aureus. The aim of this study was to assess the prevalence of different resistance phenotypes to macrolide, lincosamide, and streptogramins B (MLSB) antibiotics among erythromycin-resistant S. epidermidis, together with the evaluation of genes promoting the following different types of MLSB resistance:ermA, ermB, ermC,msrA, mphC, and linA/A'. Susceptibility to spiramycin was also examined. Among 75 erythromycin-resistantS. epidermidis isolates, the most frequent phenotypes were macrolides and streptogramins B (MSB) and constitutive MLSB (cMLSB). Moreover, all strains with the cMLSB phenotype and the majority of inducible MLSB (iMLSB) isolates were resistant to spiramycin, whereas strains with the MSB phenotype were sensitive to this antibiotic. The D-shape zone of inhibition around the clindamycin disc near the spiramycin disc was found for some spiramycin-resistant strains with the iMLSB phenotype, suggesting an induction of resistance to clindamycin by this 16-membered macrolide. The most frequently isolated gene was ermC, irrespective of the MLSB resistance phenotype, whereas the most often noted gene combination wasermC, mphC, linA/A'. The results obtained showed that the genes responsible for different mechanisms of MLSB resistance in S. epidermidis generally coexist, often without the phenotypic expression of each of them.
Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Genótipo , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/genética , Estreptogramina Grupo B/farmacologia , Clindamicina/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Eritromicina/farmacologia , Testes Genéticos/métodos , Humanos , Lincomicina/farmacologia , Fenótipo , Reação em Cadeia da Polimerase , Prevalência , Espiramicina/farmacologia , Staphylococcus epidermidis/isolamento & purificaçãoRESUMO
Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, can be regarded as potential reservoirs of resistance genes for pathogenic strains, e.g., Staphylococcus aureus. The aim of this study was to assess the prevalence of different resistance phenotypes to macrolide, lincosamide, and streptogramins B (MLSB) antibiotics among erythromycin-resistant S. epidermidis, together with the evaluation of genes promoting the following different types of MLSB resistance:ermA, ermB, ermC,msrA, mphC, and linA/A’. Susceptibility to spiramycin was also examined. Among 75 erythromycin-resistantS. epidermidis isolates, the most frequent phenotypes were macrolides and streptogramins B (MSB) and constitutive MLSB (cMLSB). Moreover, all strains with the cMLSB phenotype and the majority of inducible MLSB (iMLSB) isolates were resistant to spiramycin, whereas strains with the MSB phenotype were sensitive to this antibiotic. The D-shape zone of inhibition around the clindamycin disc near the spiramycin disc was found for some spiramycin-resistant strains with the iMLSB phenotype, suggesting an induction of resistance to clindamycin by this 16-membered macrolide. The most frequently isolated gene was ermC, irrespective of the MLSB resistance phenotype, whereas the most often noted gene combination wasermC, mphC, linA/A’. The results obtained showed that the genes responsible for different mechanisms of MLSB resistance in S. epidermidis generally coexist, often without the phenotypic expression of each of them.
Assuntos
Humanos , Farmacorresistência Bacteriana Múltipla/genética , Genótipo , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/genética , Estreptogramina Grupo B/farmacologia , Clindamicina/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Eritromicina/farmacologia , Testes Genéticos/métodos , Lincomicina/farmacologia , Fenótipo , Reação em Cadeia da Polimerase , Prevalência , Espiramicina/farmacologia , Staphylococcus epidermidis/isolamento & purificaçãoAssuntos
Farmacorresistência Bacteriana/genética , Lincosamidas/metabolismo , Nucleotidiltransferases/genética , Streptococcus agalactiae/genética , Proteínas de Bactérias/genética , Clindamicina/farmacologia , Eritromicina/farmacologia , Feminino , Humanos , Lincosamidas/farmacologia , Dados de Sequência Molecular , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/isolamento & purificaçãoAssuntos
Humanos , Varicela/complicações , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Infecções Estafilocócicas/complicações , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Infecções Estreptocócicas/complicações , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus pyogenes/efeitos dos fármacos , Estreptograminas/farmacologia , Resistência Microbiana a Medicamentos , Testes de Sensibilidade MicrobianaAssuntos
Varicela/complicações , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Infecções Estafilocócicas/complicações , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Infecções Estreptocócicas/complicações , Infecções Estreptocócicas/tratamento farmacológico , Streptococcus pyogenes/efeitos dos fármacos , Estreptograminas/farmacologia , Resistência Microbiana a Medicamentos , Humanos , Testes de Sensibilidade MicrobianaRESUMO
INTRODUCTION: In venous ulcers, the presence of Staphylococcus aureus and coagulase-negative staphylococcus resistance phenotypes can aggravate and limit the choices for treatment. METHODS: Staphylococcus isolated from 69 patients (98 ulcers) between October of 2009 and October of 2010 were tested. The macrolide, lincosamide, streptogramin B (MLS B) group resistance phenotype detection was performed using the D-test. Isolates resistant to cefoxitin and/or oxacillin (disk-diffusion) were subjected to the confirmatory test to detect minimum inhibitory concentration (MIC), using oxacillin strips (E-test®). RESULTS: The prevalence of S. aureus was 83%, and 15% of coagulase-negative staphylococcus (CoNS). In addition were detected 28% of methicillin-resistant Staphylococcus aureus (MRSA) and 47% of methicillin-resistant coagulase-negative staphylococcus (MRCoNS). Among the S. aureus, 69.6% were resistant to erythromycin, 69.6% to clindamycin, 69.6% to gentamicin, and 100% to ciprofloxacin. Considering the MRSA, 74% were highly resistant to oxacillin, MIC ≥ 256µg/mL, and the MLS Bc constitutive resistance predominated in 65.2%. Among the 20 isolates sensitive to clindamycin, 12 presented an inducible MLS B phenotype. Of the MRCoNS, 71.4%were resistant to erythromycin, ciprofloxacin and gentamicin. Considering the isolates positive for β-lactamases, the MIC breakpoint was between 0.5 and 2µg/mL. CONCLUSIONS: The results point to a high occurrence of multi-drug resistant bacteria in venous ulcers in primary healthcare patients, thus evidencing the need for preventive measures to avoid outbreaks caused by multi-drug resistant pathogens, and the importance of healthcare professionals being able to identifying colonized versus infected venous ulcers as an essential criteria to implementing systemic antibacterial therapy.
INTRODUÇÃO: Em úlceras venosas, a presença de Staphylococcus aureus e coagulase negativo com fenótipos de resistência pode constituir fator agravante e limita as opções terapêuticas. MÉTODOS: Foram avaliados estafilococos isolados de 69 pacientes, representando 98 úlceras no período de outubro de 2009 a outubro de 2010. A detecção fenotípica da resistência ao grupo macrolide, lincosamide, streptogramin B (MLS B) foi realizada pelo D-test. Isolados resistentes a cefoxitina e/ou oxacilina (disco-difusão) foram submetidos ao teste confirmatório para detecção da minimum inhibitory concentration (MIC), empregando fitas de oxacilina (E-test®). RESULTADOS: A prevalência de S. aureus foi de 83% e de 15% de coagulase-negative staphylococcus (CoNS). Identificou-se 28% de methicillin-resistant Staphylococcus aureus (MRSA) e 47% de methicillin-resistant coagulase-negative staphylococcus (MRCoNS). Entre o S. aureus, 69,6% apresentaram resistência a eritromicina, 69,6% a clindamicina, 69,6% a gentamicina e 100% a ciprofloxacina. Setenta e quatro por cento dos MRSA apresentaram elevado nível de resistência a oxacilina, MIC ≥ 256µg/mL, e em 65,2% predominou a resistência constitutiva MLS Bc. Dos 20 isolados sensíveis a clindamicina, 12 apresentaram fenótipo MLS B induzível. Um total de 71,4% dos MRCoNS apresentaram resistência a eritromicina, ciprofloxacina e gentamicina. Dos isolados positivos para a enzima β-lactamases, as MIC tiveram breakpoint entre 0,5 a 2µg/mL. CONCLUSÕES: Os resultados sinalizam elevada ocorrência de bactérias multirresistentes em úlceras venosas de pacientes recebendo atenção primária, evidenciando a necessidade de medidas preventivas que evitem surtos causados por patógenos resistentes a múltiplas drogas e a importância dos profissionais em discernir infecção de colonização em úlcera venosa, critério fundamental na indicação antibioticoterapia sistêmica.
Assuntos
Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antibacterianos/farmacologia , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Estreptogramina Grupo B/farmacologia , Úlcera Varicosa/microbiologia , Estudos Transversais , Coagulase/metabolismo , Farmacorresistência Bacteriana Múltipla , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana/métodos , Fenótipo , Prevalência , Atenção Primária à Saúde , Staphylococcus aureus/classificação , Staphylococcus aureus/enzimologiaRESUMO
INTRODUCTION: In venous ulcers, the presence of Staphylococcus aureus and coagulase-negative staphylococcus resistance phenotypes can aggravate and limit the choices for treatment. METHODS: Staphylococcus isolated from 69 patients (98 ulcers) between October of 2009 and October of 2010 were tested. The macrolide, lincosamide, streptogramin B (MLS B) group resistance phenotype detection was performed using the D-test. Isolates resistant to cefoxitin and/or oxacillin (disk-diffusion) were subjected to the confirmatory test to detect minimum inhibitory concentration (MIC), using oxacillin strips (E-test®). RESULTS: The prevalence of S. aureus was 83%, and 15% of coagulase-negative staphylococcus (CoNS). In addition were detected 28% of methicillin-resistant Staphylococcus aureus (MRSA) and 47% of methicillin-resistant coagulase-negative staphylococcus (MRCoNS). Among the S. aureus, 69.6% were resistant to erythromycin, 69.6% to clindamycin, 69.6% to gentamicin, and 100% to ciprofloxacin. Considering the MRSA, 74% were highly resistant to oxacillin, MIC ≥ 256µg/mL, and the MLS Bc constitutive resistance predominated in 65.2%. Among the 20 isolates sensitive to clindamycin, 12 presented an inducible MLS B phenotype. Of the MRCoNS, 71.4%were resistant to erythromycin, ciprofloxacin and gentamicin. Considering the isolates positive for ß-lactamases, the MIC breakpoint was between 0.5 and 2µg/mL. CONCLUSIONS: The results point to a high occurrence of multi-drug resistant bacteria in venous ulcers in primary healthcare patients, thus evidencing the need for preventive measures to avoid outbreaks caused by multi-drug resistant pathogens, and the importance of healthcare professionals being able to identifying colonized versus infected venous ulcers as an essential criteria to implementing systemic antibacterial therapy.
Assuntos
Antibacterianos/farmacologia , Lincosamidas/farmacologia , Macrolídeos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Estreptogramina Grupo B/farmacologia , Úlcera Varicosa/microbiologia , Coagulase/metabolismo , Estudos Transversais , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana/métodos , Pessoa de Meia-Idade , Fenótipo , Prevalência , Atenção Primária à Saúde , Staphylococcus aureus/classificação , Staphylococcus aureus/enzimologiaRESUMO
El objetivo de este trabajo fue determinar cepas de Stapylococcus aureus meticilino resistente de la comunidad (SARM-com) en aislamientos provenientes de infecciones de la piel de pacientes del Hospital Roosevelt y hospital nacional Pedro de Betancourt de Guatemala. Para ello se realizó un estudio exploratorio de tipo descriptivo el cual consistió en un muestreo de 12 semanas en el laboratorio de microbiología del hospital Roosevelt y del hospital nacional Pedro de Betancourt. Se recolectaron las cepas que cumplieron con los siguientes criterios: haber sido identificadas como S. aureus, que presentaran resistencia a todos los betalactámicos, por medio de la resistencia a oxacilina y como resistencia variable a macrólidos y lincosamidas...
Assuntos
Humanos , Guatemala , Hospitais , Lincosamidas/uso terapêutico , Macrolídeos/uso terapêutico , Oxacilina/efeitos adversos , Staphylococcus aureus/imunologiaRESUMO
Staphylococcus epidermidis is a normal commensal of skin that has become a serious clinical problem because of the combination of increased use of intravascular devices and an increasing number of hospitalized immunocompromised patients. In addition, there is a lack of information pertaining to resistance to macrolide, lincosamide and streptogramin type B (MLS(B)) in developing countries, including Mexico. The aim of this study was to investigate the incidence of resistance to MLS(B) antibiotics in isolates of S. epidermidis obtained in the General Hospital of Acapulco in Mexico. Susceptibility to erythromycin, clindamycin and quinupristin-dalfopristin was tested by a diffusion test, and MICs to oxacillin, erythromycin and lincomycin were determined. Differentiation between MLS(B) phenotypes was performed by a double disc diffusion test. A total of 38 of the 47 strains of S. epidermidis isolated from nosocomial infections were resistant to oxacillin [meticillin-resistant S. epidermidis (MRSE)]. The phenotypes obtained were: 18 constitutive MLS(B), 3 inducible MLS(B), 6 macrolide streptogramin and 4 lincosamide; 7 strains were susceptible to MLS(B) antibiotics. The genes associated with resistance were detected by PCR. Genotyping showed a predominance of the ermA gene followed by genes ermC and msrA. The frequency of the genes detected varied slightly from results that have been reported in isolates from other countries. Clonal types were identified by PFGE and revealed the dissemination of two major clones of MRSE in the Mexican hospital. This is believed to be the first report in Mexico on the genes associated with the MLS(B) resistance phenotype in S. epidermidis, in addition to observing a wide distribution of clonal types in the General Hospital of Acapulco, Mexico.