RESUMEN

AIMS: To evaluate the prevalence, molecular characteristics, antimicrobial susceptibility, and epithelial invasion of Streptococcus agalactiae strains isolated from pregnant women and newborns in Rio de Janeiro, Brazil. METHODS AND RESULTS: A total of 67 S. agalactiae isolates, 48 isolates from pregnant women and 19 from neonates, were analyzed. Capsular type Ia and V were predominant (35.8%/each). The multilocus sequence typing analysis revealed the presence of 19 STs grouped into 6 clonal complexes with prevalence of CC17/40.3% and CC23/34.3%. The lmb and iag virulence genes were found in 100% of isolates. Four S. agalactiae strains, belonging to CC17/ST1249 and CC23/ST23, were able to adhere to A549 respiratory epithelial cells. Antimicrobial resistance was verified mainly to tetracycline (85%), erythromycin (70.8%), and clindamycin (58.3%). Four S. agalactiae isolates were multidrug resistant. The resistance genes tested were found in 92.5% of isolates for tetM, 58.2% for ermB, 28.4% for mefAE, and 10.4% for tetO. CONCLUSION: The study showed a high prevalence of virulence and antimicrobial genes in S. agalactiae strains isolated from pregnant women and newborns, supporting the idea that continued surveillance is necessary to identify risk factors and perform long-term follow-up in pregnant women and neonates in Rio de Janeiro.

Asunto(s)

Antibacterianos , Células Epiteliales , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Infecciones Estreptocócicas , Streptococcus agalactiae , Streptococcus agalactiae/genética , Streptococcus agalactiae/efectos de los fármacos , Streptococcus agalactiae/aislamiento & purificación , Femenino , Humanos , Brasil , Embarazo , Infecciones Estreptocócicas/microbiología , Antibacterianos/farmacología , Recién Nacido , Células Epiteliales/microbiología , Farmacorresistencia Bacteriana/genética , Adulto , Factores de Virulencia/genética , Complicaciones Infecciosas del Embarazo/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Virulencia/genética

RESUMEN

Hospital bloodstream infection (BSI) caused by methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of morbidity and mortality and is frequently related to invasive procedures and medically complex patients. An important feature of MRSA is the clonal structure of its population. Specific MRSA clones may differ in their pathogenic, epidemiological, and antimicrobial resistance profiles. Whole-genome sequencing is currently the most robust and discriminatory technique for tracking hypervirulent/well-adapted MRSA clones. However, it remains an expensive and time-consuming technique that requires specialized personnel. In this work, we describe a pangenome protocol, based on binary matrix (1,0) of open reading frames (ORFs), that can be used to quickly find diagnostic, apomorphic sequence mutations that can serve as biomarkers. We use this technique to create a diagnostic screen for MRSA isolates circulating in the Rio de Janeiro metropolitan area, the RdJ clone, which is prevalent in BSI. The method described here has 100% specificity and sensitivity, eliminating the need to use genomic sequencing for clonal identification. The protocol used is relatively simple and all the steps, formulas and commands used are described in this work, such that this strategy can also be used to identify other MRSA clones and even clones from other bacterial species.

RESUMEN

Streptococcus pyogenes is known to be associated with a variety of infections, from pharyngitis to necrotizing fasciitis (flesh-eating disease). S. pyogenes of the ST62/emm87 lineage is recognized as one of the most frequently isolated lineages of invasive infections caused by this bacterium, which may be involved in hospital outbreaks and cluster infections. Despite this, comparative genomic and phylogenomic studies have not yet been carried out for this lineage. Thus, its virulence and antimicrobial susceptibility profiles are mostly unknown, as are the genetic relationships and evolutionary traits involving this lineage. Previously, a strain of S. pyogenes ST62/emm87 (37-97) was characterized in our lab for its ability to generate antibiotic-persistent cells, and therapeutic failure in severe invasive infections caused by this bacterial species is well-reported in the scientific literature. In this work, we analyzed genomic and phylogenomic characteristics and evaluated the virulence and resistance profiles of ST62/emm87 S. pyogenes from Brazil and international sources. Here we show that strains that form this lineage (ST62/emm87) are internationally spread, involved in invasive outbreaks, and share important virulence profiles with the most common emm types of S. pyogenes, such as emm1, emm3, emm12, and emm69, which are associated with most invasive infections caused by this bacterial species in the USA and Europe. Accordingly, the continued increase of ST62/emm87 in severe S. pyogenes diseases should not be underestimated.

RESUMEN

BACKGROUND: Typing of staphylococcal cassette chromosome mec (SCCmec) elements is commonly used for studies on the molecular epidemiology of MRSA. OBJECTIVES: To perform an investigation centred on uncovering the reasons for misclassification of MRSA clonal complex 5 (CC5) SCCmec type II clinical isolates in our laboratory. METHODS: MRSA isolates from CC5 were subjected to WGS and SCCmec typing. RESULTS: This investigation led to the discovery that the classification failure was due to an insertion of IS1272 carrying the fabI gene on a transposable element (TnSha1) that confers increased MIC to the biocide triclosan. Genomic analysis revealed that fabI was present in 25% of the CC5 MRSA isolates sampled. The frequency of TnSha1 in our collection was much higher than that observed among publicly available genomes (0.8%; n = 24/3142 CC5 genomes). Phylogenetic analyses revealed that genomes in different CC5 clades carry TnSha1 inserted in different integration sites, suggesting that this transposon has entered CC5 MRSA genomes on multiple occasions. In at least two genotypes, ST5-SCCmecII-t539 and ST5-SCCmecII-t2666, TnSha1 seems to have entered prior to their divergence. CONCLUSIONS: Our work highlights an important misclassification problem of SCCmecII in isolates harbouring TnSha1 when Boye's method is used for typing, which could have important implications for molecular epidemiology of MRSA. The importance of increased-MIC phenotype is still a matter of controversy that deserves more study given the widespread use of triclosan in many countries. Our results suggest expanding prevalence that may indicate strong selection for this phenotype.

Asunto(s)

Staphylococcus aureus Resistente a Meticilina , Infecciones Estafilocócicas , Triclosán , Humanos , Infecciones Estafilocócicas/epidemiología , Triclosán/farmacología , Pruebas de Sensibilidad Microbiana , Filogenia , ADN Bacteriano/genética , Cromosomas

RESUMEN

Streptococcus pyogenes (group A Streptococcus-GAS) is an important pathogen for humans. GAS has been associated with severe and invasive diseases. Despite the fact that these bacteria remain universally susceptible to penicillin, therapeutic failures have been reported in some GAS infections. Many hypotheses have been proposed to explain these antibiotic-unresponsive infections; however, none of them have fully elucidated this phenomenon. In this study, we show that GAS strains have the ability to form antimicrobial persisters when inoculated on abiotic surfaces to form a film of bacterial agglomerates (biofilm-like environment). Our data suggest that efflux pumps were possibly involved in this phenomenon. In fact, gene expression assays by real-time qRT-PCR showed upregulation of some genes associated with efflux pumps in persisters arising in the presence of penicillin. Phenotypic reversion assay and whole-genome sequencing indicated that this event was due to non-inherited resistance mechanisms. The persister cells showed downregulation of genes associated with protein biosynthesis and cell growth, as demonstrated by gene expression assays. Moreover, the proteomic analysis revealed that susceptible cells express higher levels of ribosome proteins. It is remarkable that previous studies have reported the recovery of S. pyogenes viable cells from tissue biopsies of patients presented with GAS invasive infections and submitted to therapy with antibiotics. The persistence phenomenon described herein brings new insights into the origin of therapeutic failures in S. pyogenes infections. Multifactorial mechanisms involving protein synthesis inhibition, cell growth impairment and efflux pumps seem to play roles in the formation of antimicrobial persisters in S. pyogenes.

RESUMEN

The presence of Kerstersia gyiorum in lower leg wounds has been reported in case studies from several countries. OBJECTIVE: This study evaluated the antimicrobial susceptibility profile of K gyiorum isolated from a chronic wound. METHODS: An 85-year-old woman with chronic venous insufficiency presented to an intermediate care unit in Niteroi City, Rio de Janeiro, Brazil, with an instep chronic wound of 14 cm² with wound duration of 6 months. K gyiorum was identified by matrix-assisted laser desorption ionization-time of flight, confirmed by 16S rRNA partial sequence analysis, and classified as resistant for ciprofloxacin by reagent strips(minimum inhibitory concentration [MIC] = 32 µg/mL) and the broth macrodilution method (MIC = 8 µg/mL). Intermediate resistance for ciprofloxacin was verified by microscan (MIC = 2 µg/mL). CONCLUSION: The authors identified the first, to their knowledge, lower leg wound with K gyiorum in Brazil and verified that it was ciprofloxacin resistant.

Asunto(s)

Alcaligenaceae/efectos de los fármacos , Ciprofloxacina/uso terapéutico , Resistencia a la Enfermedad/efectos de los fármacos , Úlcera de la Pierna/tratamiento farmacológico , Cicatrización de Heridas/efectos de los fármacos , Anciano de 80 o más Años , Alcaligenaceae/patogenicidad , Brasil , Femenino , Humanos , Úlcera de la Pierna/fisiopatología , Pruebas de Sensibilidad Microbiana/estadística & datos numéricos , Cicatrización de Heridas/fisiología

RESUMEN

Introduction. In some species, the population structure of pathogenic bacteria is clonal. However, the mechanisms that determine the predominance and persistence of specific bacterial lineages of group C Streptococcus remain poorly understood. In Brazil, a previous study revealed the predominance of two main lineages of Streptococcus dysgalactiae subsp. equisimilis (SDSE).Aim. The aim of this study was to assess the virulence and fitness advantages that might explain the predominance of these SDSE lineages for a long period of time.Methodology. emm typing was determined by DNA sequencing. Adhesion and invasion tests were performed using human bronchial epithelial cells (16HBE14o-). Biofilm formation was tested on glass surfaces and the presence of virulence genes was assessed by PCR. Additionally, virulence was studied using Caenorhabditis elegans models and competitive fitness was analysed in murine models.Results. The predominant lineages A and B were mostly typed as emm stC839 and stC6979, respectively. Notably, these lineages exhibited a superior ability to adhere and invade airway cells. Furthermore, the dominant lineages were more prone to induce aversive olfactory learning and more likely to kill C. elegans. In the competitive fitness assays, they also showed increased adaptability. Consistent with the increased virulence observed in the ex vivo and in vivo models, the predominant lineages A and B showed a higher number of virulence-associated genes and a superior ability to accumulate biofilm.Conclusion. These results suggest strongly that this predominance did not occur randomly but rather was due to adaptive mechanisms that culminated in increased colonization and other bacterial properties that might confer increased bacteria-host adaptability to cause disease.

Asunto(s)

Biodiversidad , Infecciones Estreptocócicas/microbiología , Streptococcus/patogenicidad , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Brasil , Caenorhabditis elegans , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Streptococcus/clasificación , Streptococcus/genética , Streptococcus/aislamiento & purificación , Virulencia

RESUMEN

Streptococcus dysgalactiae subsp. equisimilis (SDSE) isolates are the most common group C streptococci in humans and reports of invasive infections associated with SDSE have been increasing. Molecular epidemiology studies are an important strategy to trace the emergence and spread of possible well-fit bacterial pathogens of humans and animals. In this work, we analysed the antimicrobial and clonal profiles of 115 SDSE infection and colonization isolates of human and equine origin. PFGE revealed the spread of two main clusters: clone A (57.4%) and clone A (26.1%). Remarkably, two isolates from clone B obtained from human colonization cases displayed identical PFGE patterns to those of three equine infection isolates. In addition, multilocus sequence typing allocated these isolates to ST129 (CC31). All of the SDSE isolates were susceptible to penicillin, vancomycin, gentamicin, levofloxacin and chloramphenicol. Tetracycline and erythromycin resistance rates were 65.2 and 13.9% respectively. Nevertheless, none of the isolates displaying sporadic PFGE patterns showed erythromycin resistance. The majority of erythromycin-resistant isolates from clone A had inducible resistance to macrolides, lincosamines and streptogramins B (iMLSB phenotype), which is associated with the presence of the ermA gene, whereas the resistant isolates from clone B showed the M phenotype, associated with the mefA gene. In conclusion, the data indicated that the analysed collection of SDSE isolates displayed a clonal structure and that the isolates found in human colonization cases could also be involved in equine infections.

Asunto(s)

Farmacorresistencia Bacteriana , Variación Genética , Tipificación de Secuencias Multilocus , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/veterinaria , Streptococcus/clasificación , Streptococcus/aislamiento & purificación , Animales , Antibacterianos/farmacología , Brasil/epidemiología , Análisis por Conglomerados , Electroforesis en Gel de Campo Pulsado , Genotipo , Caballos , Humanos , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Streptococcus/genética

RESUMEN

Procedures of sterilization and disinfection are essential to ensure that medical and surgical instruments will not transmit infectious pathogens to patients. In the present paper, we tested the residual effect of these compounds on biofilm formation and its efficiency in disrupting preformed biofilms using methicillin-resistant Staphylococcus aureus (MRSA) isolates of the lineage ST239-SCCmecIII. All compounds examined, except 70% alcohol, caused a significant impairment in biofilm formation with concomitant inhibition of cell growth. Among the compounds examined, 10% povidone-iodine (PVP-I) was the only antiseptic that exhibited more than 90% reduction of both biofilm formation and dispersion. In the group of sterilants and disinfectants, a formulation containing 7% hydrogen peroxide and 0.2% peracetic acid (HP-PA), and sodium hypochlorite with 1% active chlorine (NaOCl) were equally effective.

Asunto(s)

Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Desinfectantes/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/fisiología , Desinfección/métodos , Humanos

RESUMEN

The aim of the present paper was to compare different methods for detecting methicillin resistance in Staphylococcus aureus. Among the isolates analyzed, 52 belonged to MRSA international lineages commonly detected in the American continent and 14 to sporadic MRSA clones. Both 30 microg-cefoxitin disk and PBP2a had 100% sensibility/specificity when the low-level heterogeneous isolates were tested and, thus, are highly recommended.

Asunto(s)

Pruebas Antimicrobianas de Difusión por Disco/métodos , Resistencia a la Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/genética , Antibacterianos/farmacología , Técnicas de Tipificación Bacteriana , Cefoxitina/farmacología , Humanos , Meticilina/farmacología , Staphylococcus aureus Resistente a Meticilina/clasificación , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , América del Norte , Oxacilina/farmacología , Sensibilidad y Especificidad , América del Sur

RESUMEN

Staphylococcus aureus is an important nosocomial and community-acquired pathogen. Hospital infections are frequently complicated by the ability of bacteria to form biofilms on different surfaces. The development of bacterial films on medical indwelling devices, such as prostheses, often requires surgical procedures to remove the contaminated implant. Indeed, biofilm formation on central endovenous catheters is a major cause of primary bacteraemia in hospitals. The modulation of virulence factors in S. aureus is orchestrated by a number of global regulators including agr RNAIII. To improve our understanding of the role of the agr quorum-sensing system in biofilm formation by S. aureus, we constructed a number of agr-null mutants, derived from contemporary clinical isolates. Analysis of these mutants indicates that agr has a significant impact on biofilm development for most of the isolates tested. Our data show that RNAIII can control both biofilm formation and accumulation. The agr effect included both up- and downregulation of biofilms, even for isolates within the same lineage, corroborating the hypothesis that the mechanisms involved in S. aureus biofilms are complex and probably multifactorial.

Asunto(s)

Proteínas Bacterianas/genética , Biopelículas/crecimiento & desarrollo , Regulación Bacteriana de la Expresión Génica , Glucosa/metabolismo , ARN Bacteriano/genética , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/fisiología , Transactivadores/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Humanos , Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Staphylococcus aureus Resistente a Meticilina/patogenicidad , Staphylococcus aureus Resistente a Meticilina/fisiología , Datos de Secuencia Molecular , ARN Bacteriano/metabolismo , Alineación de Secuencia , Staphylococcus aureus/genética , Staphylococcus aureus/aislamiento & purificación , Staphylococcus aureus/patogenicidad , Transactivadores/metabolismo , Factores de Virulencia/genética , Factores de Virulencia/metabolismo

RESUMEN

Community-acquired infections by methicillin-resistant Staphylococcus aureus (CA-MRSA) in the absence of classic risk factors for MRSA diseases have been reported in different continents. In the article presented here, using molecular typing methods as pulsed-field gel electrophoresis, staphylococcal cassette chromosome mec typing, and multilocus sequence typing, we characterized CA-MRSA isolates from Rio Janeiro and Porto Alegre. The results indicated the presence of international CA-MRSA clones in these 2 Brazilian cities. In addition, Panton-Valentine leukocidin and a number of staphylococcal enterotoxin encoding genes were accessed in these MRSA isolates by polymerase chain reaction detection.

Asunto(s)

Resistencia a la Meticilina/genética , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus/aislamiento & purificación , Toxinas Bacterianas/genética , Brasil/epidemiología , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/genética , Infecciones Comunitarias Adquiridas/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Electroforesis en Gel de Campo Pulsado , Exotoxinas/genética , Genotipo , Humanos , Leucocidinas/genética , Reacción en Cadena de la Polimerasa , Infecciones Estafilocócicas/clasificación , Infecciones Estafilocócicas/genética , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética

RESUMEN

OBJECTIVES: To study biofilm production and to detect icaAD, atlE and aap genes in 137 isolates of methicillin-resistant Staphylococcus epidermidis (MRSE) obtained from healthy individuals from the community (35 isolates), from hospitalized patients at the Antônio Pedro University Hospital (25 isolates) and from individuals from a home-care system (HCS; 77 isolates). METHODS: Biofilm production was determined in vitro using polystyrene inert surfaces. icaAD, atlE and aap genes were detected using PCR. Hybridization experiments were also carried out to confirm some PCR results. Antimicrobial susceptibility testing was carried out using the NCCLS methods. RESULTS: Although many of the commensal MRSE isolates produced biofilms, the percentage of biofilm producers was significantly higher (P = 0.0107) among hospital isolates (76%) than among isolates from the community (60%) and from the HCS (57%). An association was observed between multiresistance and biofilm production for isolates obtained from healthy individuals from the community and from household contacts from the HCS (P < 0.0001). The concomitant presence of the ica operon and atlE and aap genes was associated with the strong biofilm-producer phenotype (P < 0.0001). CONCLUSION: Because many of the commensal MRSE isolates obtained from nares produced biofilms and carried icaAD, aap and atlE genes, biofilms or such genetic elements should not be used as markers for clinical significance. The biofilm environment seems to increase genetic exchanges and hence may contribute to multiresistance phenotypes.

Asunto(s)

Antibacterianos/farmacología , Biopelículas/crecimiento & desarrollo , Genes Bacterianos , Resistencia a la Meticilina/genética , Staphylococcus epidermidis/fisiología , Adhesión Bacteriana/fisiología , Secuencia de Bases , ADN Bacteriano/genética , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Poliestirenos , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/aislamiento & purificación

RESUMEN

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has recently emerged in the southwestern Pacific, North America, and Europe. These S. aureus isolates frequently shared some genetic characteristics, including the SCCmec type IV and lukS-lukF genes. In this paper we show that typical CA-MRSA isolates have spread to South America (Brazil).

Asunto(s)

Enfermedades Transmisibles Emergentes/epidemiología , Infecciones Comunitarias Adquiridas/epidemiología , Resistencia a la Meticilina , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus/aislamiento & purificación , Adulto , Proteínas Bacterianas/genética , Técnicas de Tipificación Bacteriana , Enfermedades Transmisibles Emergentes/microbiología , Infecciones Comunitarias Adquiridas/microbiología , ADN Bacteriano/análisis , Electroforesis en Gel de Campo Pulsado , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , América del Sur/epidemiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/clasificación , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética

RESUMEN

Penicillin has been the antimicrobial of choice for the treatment of Streptococcus pyogenes infections for almost six decades. Although penicillin-resistant isolates have not been described to date, clinical failures have been reported after treatment with beta-lactams. In this study, we analysed the antimicrobial susceptibility and genetic diversity of S. pyogenes isolates obtained from healthy carriers or patients in different cities in the south and south east of Brazil. The MICs were determined for penicillin and seven other antimicrobials. Penicillin tolerance was also investigated. Genetic diversity was analysed by PFGE after SmaI fragmentation of the genomic DNA. All 211 isolates tested were susceptible to penicillin (MIC 0.0025-0.02 mg l(-1)). Four isolates were moderately penicillin-tolerant (MBC/MIC = 16 mg l(-1)). Most of the other drugs tested were very active against the strains examined, except for tetracycline, to which 50 % of strains were resistant. We also found extensive genetic diversity, in that 60 different patterns were recognized in the 96 strains studied. Indeed, we found no correlation between tetracycline resistance and clonality. Despite this diversity, some PFGE patterns persisted for up to 18 years and specific clone types were spread over different geographical locations

Asunto(s)

Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple , Variación Genética , Streptococcus pyogenes/efectos de los fármacos , Streptococcus pyogenes/genética , Brasil , Humanos , Pruebas de Sensibilidad Microbiana , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/aislamiento & purificación , Factores de Tiempo

RESUMEN

Coagulase-negative staphylococci (CNS) have emerged as an important pathogen in nosocomial infections. About 80%-90% of CNS isolates associated with hospital infections are methicillin-resistant coagulase-negative staphylococci (MRCNS). The aims of this study were to screen for MRCNS isolates in the flora of a small population of patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and to evaluate the discriminatory power of different molecular methods: pulsed-field gel electrophoresis (PFGE), mecA location, ClaI/mecA polymorphism and arbitrarily primed polymerase chain reaction (AP-PCR) for characterizing isolates of methicillin-resistant Staphylococcus epidermidis (MRSE). Seventy-nine CNS isolates were recovered from the 11 CAPD patients studied. Using a methicillin screening agar and a DNA specific mecA probe we verified that 30 of the 79 (38%) CNS isolates were resistant to methicillin (MRCNS). Twenty-two of the 30 MRCNS (73%) were MRSE, 7 (23%) methicillin-resistant S. haemolyticus (MRSH(ae)) and 1 (3%) methicillin-resistant S. hominis (MRSH(om)). All patients analyzed carried MRCNS in their flora, in one or more sites. Since CAPD patients have high risk for developing peritonitis, the colonization of these patients with MRCNS might represent an additional problem, due to the therapeutic restrictions imposed by these multiresistant isolates. A wide genetic diversity was verified when the PFGE of the MRSE isolates was analyzed. The 22 MRSE isolates displayed a total of 15 PFGE different patterns (11 PFGE types and 4 subtypes). The location of mecA in the SmaI-fragmented genome DNA did not bring any additional advantage for epidemiologic characterization of the isolates. The ClaI/mecA polymorphism was able to correctly discriminate 12 from the 15 PFGE patterns. In addition, the DNA of 20 MRSE isolates were used for AP-PCR typing. These isolates belonged to 14 PFGE patterns (11 types and 3 subtypes) and displayed 15 genotypes (for the association of PFGE, mecA location and ClaI/mecA polymorphism). A total of 17 different amplification patterns was verified using the primer 1. Only for 2 genotypes, strains having identical genetic backgrounds were further discriminated by AP-PCR (2 of 15 genotypes (87%) for AP-PCR and 1 of 15 genotypes for PFGE; (93%). Concluding, our results indicated that the AP-PCR can be an alternative and useful tool for monitoring and genotyping MRSE colonization and also to molecular characterizing MRSE outbreaks in hospitals.

Asunto(s)

Antibacterianos/farmacología , Resistencia a la Meticilina , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/aislamiento & purificación , Técnicas Bacteriológicas , Secuencia de Bases , Coagulasa/metabolismo , Electroforesis en Gel de Campo Pulsado , Humanos , Fallo Renal Crónico/terapia , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Diálisis Peritoneal Ambulatoria Continua/efectos adversos , Reacción en Cadena de la Polimerasa/métodos , Sensibilidad y Especificidad , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus/efectos de los fármacos , Staphylococcus/enzimología , Staphylococcus/aislamiento & purificación