Typing of Enterococcus faecium by polymerase chain reaction and pulsed field gel electrophoresis

Polymerase chain reaction (PCR) with JB1 or REP consensus oligonucleotides and pulsed field gel electrophoresis (PFGE) were used to study genomic DNA extracted from 31 strains of enterococci. Eleven ATCC strains, representative of 11 species of Enterococcus, were initially tested by JB1-PCR, revealing that Enterococcus malodoratus and Enterococcus hirae presented identical banding patterns. Eight Enterococcus faecium isolates from Stanford University and 12 from São Paulo Hospital were studied by JB1-PCR, REP-PCR 1/2R and PFGE. Among the isolates from Stanford University, 5 genotypes were defined by JB1-PCR, 7 by REP-PCR 1/2R and 4 by PFGE. Among the isolates from São Paulo Hospital, 9 genotypes were identified by JB1-PCR, 6 by REP-PCR and 5 by PFGE. The three methods identified identical genotypes, but there was not complete agreement among them.Universidade Estadual de Maringá Centro de Ciências da Saúde Departamento de EnfermagemUniversidade Federal de São Paulo (UNIFESP) Departamento de Doenças Infecciosas e ParasitáriasUNIFESP, Depto. de Doenças Infecciosas e ParasitáriasSciEL

Phagocytosis and killing of epidemic methicillin-resistant Staphylococcus aureus by human neutrophils and monocytes

Staphylococcus aureus is a pathogen that has been associated with nosocomial infections since the preantibiotic era. Since the introduction of antibiotics in medical practice in the 1940 s, methicillin-resistant S. aureus (MRSA) strains have been emerging in various parts of the world. In view of the important role of the phagocytic system in the defense against this bacteria, we decided to study phagocytosis by neutrophils and monocytes of an epidemic MRSA strain in São Paulo, Brazil, in comparison with methicillin-sensitive strains. Complement system opsonins are fundamental for efficient ingestion of the resistant and sensitive strains by both types of phagocytes. We found no association of the opsonic requirement of the MRSA strain with the multiresistance phenotype. On the other hand, the MRSA strain was found to be more resistant to the effector mechanisms of neutrophils than both sensitive strains when opsonized with fresh serum, despite the phagocytosis results. This fact suggests that the intracellular killing of S. aureus is an additional parameter of bacterial virulence, but new approaches must be implemented to study the interactions of this MRSA strain with phagocytes in order to investigate the possible factors involved in its behavior in response to neutrophil effector mechanisms.Adolfo Lutz Institute Immunology SectionFederal University of São Paulo Department of Infectious and Parasitic DiseasesUNIFESP, Department of Infectious and Parasitic DiseasesSciEL

Molecular characterization of carbapenem-resistant and metallo-β-lactamase-producing Pseudomonas aeruginosa isolated from blood cultures from children and teenagers with cancer

INTRODUCTION: The objective of this study was to evaluate the prevalence and dissemination of carbapenem-resistant and metallo-β-lactamase-producing Pseudomonas aeruginosa isolated from blood-stream samples (2000-2005) that were collected from patients admitted to the Institute of Pediatric Oncology, UNIFESP (IOP-GRAACC). METHODS AND RESULTS: Fifty-six P. aeruginosa samples were isolated from 49 patients. Thirty-two of these samples were classified as carbapenem-resistant using the disc diffusion method and were subjected to the PCR reaction in order to detect MBL genes. Eighteen of these 32 isolates showed the blaSPM-1 gene. Eight samples selected in different years over the study period presented the same genetic profile according to pulsed-field gel electrophoresis. The antimicrobial therapy was considered adequate for only 23.5% of the patients with bacteremia due to P. aeruginosa carrying the blaSPM-1 gene, and a high lethality rate of 70.6% was observed during the 30-day period after bacteremia and an inadequate initial antibiotic regimen. CONCLUSIONS: We detected the presence of a clone of carbapenem-resistant P. aeruginosa carrying blaSPM-1 that persisted in blood culture samples over a six-year period at the institution, with high lethality, thus justifying rigorous epidemiological surveillance and a rearrangement of the antimicrobial therapy regimens at the institution.INTRODUCÃO: O objetivo do estudo foi avaliar a prevalência e a disseminação de amostras de Pseudomonas aeruginosa resistente aos carbapenêmicos e produtoras de metalo-β-lactamases isoladas de hemoculturas (2000-2005) de pacientes do Instituto de Oncologia Pediátrica da UNIFESP (IOP-GRAACC). MÉTODOS E RESULTADOS: Cinquenta e seis amostras de Pseudomonas aeruginosa foram isoladas de 49 pacientes. Trinta e duas dessas amostras foram classificadas como resistentes aos carbapenêmicos pela técnica de disco difusão e submetidas a reação de PCR para detecção de genes de MBL. Dezoitos dessas 32 amostras evidenciaram o gene blaSPM-1. Oito amostras selecionadas em diferentes anos no período de estudo apresentaram o mesmo perfil genético por pulsed-field gel electrophoresis. A terapêutica antimicrobiana foi considerada adequada em apenas 23,5% dos pacientes com bacteremia por P. aeruginosa carreando blaSPM-1 e letalidade de 70,6% no período de até 30 dias após a bacteremia e uma inadequação inicial dos esquemas antibióticos utilizados CONCLUSÕES: Evidenciamos a presença de um clone de P. aeruginosa resistente aos carbapenêmicos carreando blaSPM-1 que persistiu em amostras de hemocultura pelo período de 6 anos na instituição, com alta letalidade, justificando uma vigilância epidemiológica rigorosa e uma readequação dos esquemas de terapia antimicrobianos na instituição.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Laboratório Especial em Microbiologia ClínicaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Instituto de Oncologia Pediátrica-Grupo de Apoio ao Adolescente e à Criança com CâncerUNIFESP, EPM, Laboratório Especial em Microbiologia ClínicaUNIFESP, EPM, Instituto de Oncologia Pediátrica-Grupo de Apoio ao Adolescente e à Criança com CâncerSciEL

Oral infection by the Human Papilloma Virus in women with cervical lesions at a prison in São Paulo, Brazil

Carcinoma of the head and neck is the 6th cause of death by cancer in the world. In recent decades the human papillomavirus (HPV) has been implicated in the etiology of this disease. OBJECTIVE: To characterize the types of HPV detected in the oral mucosa in women with cytological abnormalities suggesting intraepithelial squamous lesions in the uterine cervix. METHODS: four-hundred-nine cervical-vaginal and oral pap-smears of women interned in a Female Prison in São Paulo were examined. The relationship between cervical and oral lesion was analyzed by PCR/RFLP and DNA sequencing. RESULTS: Of 27 (6.67%) specimens showing cervical cytological abnormalities suggesting LSIL and HSIL, 22 (81.48%) had oncogenic high-risk HPV infection, of which HPV 59 was the most prevalent. Three (11.1%) samples showed cytological changes suggesting mild dysplasia in the oral cavity. CONCLUSION: Our study suggests an association between carcinoma of the oral cavity and HPV infection, regardless of the virus type.O carcinoma de cabeça e pescoço é 6ª maior causa de mortes por neoplasia no mundo. Nas últimas décadas, tem-se associado a relação da infecção pelo Papilomavírus Humano (HPV) e seu envolvimento na etiologia desta doença, bem como acontece com o câncer de colo de útero. OBJETIVO: A caracterização molecular dos tipos de HPV diagnosticados na mucosa oral de mulheres que apresentavam alterações citológicas compatíveis com lesão escamosa no colo uterino. MÉTODOS: Foram estudadas 409 amostras cérvico-vaginais e de cavidade oral de mulheres internas no Presídio Feminino da cidade de São Paulo. A correlação entres lesões cervicais e orais foram avaliadas em 27 mulheres que apresentavam lesões pré-malignas e malignas no colo uterino pela caracterização molecular dos tipos de HPV por PCR/ RFLP e Sequenciamento. RESULTADOS: Das 27 (6,67%) amostras compatíveis com LSIL e HSIL no colo uterino, 22 (81,48%) apresentaram infecção pelo HPV de alto risco oncogênico, sendo o HPV 59 o mais prevalente, dentre elas, três amostras (11,1%) evidenciaram alterações celulares compatíveis com displasia leve na cavidade oral. CONCLUSÃO: Nosso estudo sugere uma relação entre o desenvolvimento de lesões da cavidade oral e a infecção pelo HPV, independentemente do tipo viral presente.UNIFESPLaboratório Afip departamento de biologia molecularUNIFESPSciEL

Characterization of bacteriophages infecting clinical isolates of Pseudomonas aeruginosa stored in a culture collection

Some clinical isolates of Pseudomonas aeruginosa stored in our culture collection did not grow or grew poorly and showed lysis on the culture plates when removed from the collection and inoculated on MacConkey agar. One hypothesis was that bacteriophages had infected and killed those clinical isolates. To check the best storage conditions to maintain viable P. aeruginosa for a longer time, clinical isolates were stored at various temperatures and were grown monthly. We investigated the presence of phage in 10 clinical isolates of P. aeruginosa stored in our culture collection. Four strains of P. aeruginosa were infected by phages that were characterized by electron microscopy and isolated to assess their ability to infect. The best condition to maintain the viability of the strains during storage was in water at room temperature. Three Siphoviridae and two Myoviridae phages were visualized and characterized by morphology. We confirmed the presence of bacteriophages infecting clinical isolates, and their ability to infect and lyse alternative hosts. Strain PAO1, however, did not show lysis to any phage. Mucoid and multidrug resistant strains of P. aeruginosa showed lysis to 50% of the phages tested.Universidade Federal de São Paulo (UNIFESP) Divisao de Doencas Infecciosas Laboratorio Especial de Microbiologia ClinicaInstituto Adolfo Lutz Nucleo de Microscopia EletronicaUNIFESP, Divisao de Doencas Infecciosas Laboratorio Especial de Microbiologia ClinicaSciEL

Molecular typing of antimicrobial-resistant Shiga-toxin-producing Escherichia coli strains (STEC) in Brazil

Antimicrobial resistance patterns and molecular characteristics were determined in thirty-two Shiga-toxin-producing Escherichia coli (STEC) strains previously identified in São Paulo State associated with human infections (n = 21) and in cattle feces (n = 11). the highest resistance rates were identified for tetracycline (100%), streptomycin (78%) and trimethoprim sulfamethoxazole (56%). Eleven STEC strains showed resistance to ampicillin and carried bla(TEM) that was confirmed as bla(TEM-1) in one representative isolate. the class 1 integrase gene (intI1) was detected in seven (22%) strains, and most of them belonged to the O111:H8 serotype. the class 1 integron was located on plasmids in five of the seven STEC strains, and conjugation assays confirmed the plasmid support of those resistant determinants. STEC strains were genetically classified into the B I group, and PFGE analysis showed that most of the strains in each serogroup were grouped into the same cluster (80-97% similarity). the presence of a class 1 integron and bla(TEM-1) genes is described for the first time among STEC isolates in Brazil and clearly represents a public health concern. (C) 2010 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Div Infect Dis, BR-04023062 São Paulo, BrazilJMI Labs, N Liberty, IA USAUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Div Infect Dis, BR-04023062 São Paulo, BrazilWeb of Scienc

Spatial exploration of Streptococcus pneumoniae clonal clustering in São Paulo, Brazil

OBJECTIVES: To examine the spatial distribution of Streptococcus pneumoniae and its clonal patterns collected between 2002 and 2006 in São Paulo, Brazil. METHODS: As part of an observational study in São Paulo city, Brazil, S. pneumoniae isolates routinely cultured from blood, respiratory specimens, or cerebrospinal and other profound fluids were selected. Additionally, only isolates with either penicillin (PEN) intermediate (I) or resistant (R) status on routine antibiogram were included, in order to obtain a higher probability of clonal isolates. A single I/R S. pneumoniae isolate per patient was included and submitted to genotypic determination by pulsed field gel electrophoresis (PFGE). Minimum inhibitory concentrations (MICs) were determined for the isolates by Etest® to PEN and other antimicrobials. Each isolate was geocoded in a digital map. The Kernel function and ratio methods between total isolates vs. clones were used in order to explore possible cluster formations. RESULTS: Seventy-eight (78) S. pneumoniae community isolates from two major outpatient centers in São Paulo, Brazil, were selected from the databank according to their penicillin susceptibility profile, i.e. R or I to penicillin assessed by oxacillin disc diffusion. Of these, 69 were submitted to PFGE, 65 to MIC determination, and 48 to spatial analytical procedures. Preliminary spatial analysis method showed two possible cluster formation located in southwest and southeast regions of the city. CONCLUSION: Further analyses are required for precisely determining the existence of S. pneumoniae clusters and their related risk factors. Apparently there is a specific transmission pattern of S. pneumoniae clones within certain regions and populations. GIS and spatial methods can be applied to better understand epidemiological patterns and to identify target areas for public health interventions.Universidade Federal de São Paulo (UNIFESP) Special Laboratory of Clinical MicrobiologyHospital Israelita Albert EinsteinGC-2 Gestão do Conhecimento Científico LtdInstituto Nacional de Pesquisas Espaciais Department of Image ProcessingUNIFESP, Special Laboratory of Clinical MicrobiologySciEL

Pharmacodynamic profiling of commonly prescribed antimicrobial drugs against Escherichia coli isolates from urinary tract

Since antimicrobial resistance among uropathogens against current first line agents has affected the management of severe urinary tract infection, we determined the likelihood that antibiotic regimens achieve bactericidal pharmacodynamic exposures using Monte Carlo simulation for five antimicrobials (ciprofloxacin, ceftriaxone, piperacillin/tazobactam, ertapenem, and meropenem) commonly prescribed as initial empirical treatment of inpatients with severe community acquired urinary tract infections. Minimum inhibitory concentration determination by Etest was performed for 205 Brazilian community urinary tract infection Escherichia coli strains from 2008 to 2012 and 74 E. coli bloodstream strains recovered from a surveillance study. Pharmacodynamic exposure was modeled via a 5000 subject Monte Carlo simulation. All isolates were susceptible to ertapenem and meropenem. Piperacillin/tazobactam, ceftriaxone and ciprofloxacin showed 100%, 97.5% and 83.3% susceptibility among outpatient isolates and 98.6%, 75.7% and 64.3% among inpatient isolates, respectively. Against outpatient isolates, all drugs except ciprofloxacin (82.7% in aggressive and 77.6% in conservative scenarios) achieved high cumulative fraction of response: car-bapenems and piperacillin/tazobactam cumulative fraction of responses were close to 100%, and ceftriaxone cumulative fraction of response was 97.5%. Similar results were observed against inpatients isolates for carbapenems (100%) and piperacillin/tazobactam (98.4%), whereas ceftriaxone achieved only 76.9% bactericidal cumulative fraction of response and ciprofloxacin 61.9% (aggressive scenario) and 56.7% (conservative scenario) respectively. Based on this model, standard doses of beta-lactams were predicted to deliver sufficient pharmacodynamic exposure for outpatients. However, ceftriaxone should be avoided for inpatients and ciprofloxacin empirical prescription should be avoided in both inpatients and outpatients with complicated urinary tract infection.Merck Sharp & DohmeUniversidade Federal de São Paulo (UNIFESP) Department of Infectology Laboratório Especial de Microbiologia ClínicaUNIFESP, Department of Infectology Laboratório Especial de Microbiologia ClínicaSciEL