Adhesion, biofilm and genotypic characteristics of antimicrobial resistant Escherichia coli isolates

Aggregative adherence to human epithelial cells, most to renal proximal tubular (HK-2) cells, and biofilm formation was identified among antimicrobial resistant Escherichia coli strains mainly isolated from bacteremia. The importance of these virulence properties contributing to host colonization and infection associated with multiresistant E. coli should not be neglected.

Surveillance programs for detection and characterization of emergent pathogens and antimicrobial resistance: results from the Division of Infectious Diseases, UNIFESP

Several epidemiological changes have occurred in the pattern of nosocomial and community acquired infectious diseases during the past 25 years. Social and demographic changes possibly related to this phenomenon include a rapid population growth, the increase in urban migration and movement across international borders by tourists and immigrants, alterations in the habitats of animals and arthropods that transmit disease, as well as the raise of patients with impaired host defense abilities. Continuous surveillance programs of emergent pathogens and antimicrobial resistance are warranted for detecting in real time new pathogens, as well as to characterize molecular mechanisms of resistance. In order to become more effective, surveillance programs of emergent pathogens should be organized as a multicenter laboratory network connected to the main public and private infection control centers. Microbiological data should be integrated to guide therapy, adapting therapy to local ecology and resistance patterns. This paper presents an overview of data generated by the Division of Infectious Diseases, Federal University of São Paulo, along with its participation in different surveillance programs of nosocomial and community acquired infectious diseases.

Várias alterações epidemiológicas ocorreram no perfil das doenças infecciosas hospitalares e comunitárias nos últimos 25 anos. Mudanças sociais e demográficas possivelmente relacionadas com esse fenômeno incluem o rápido crescimento populacional, o aumento da migração urbana e deslocamento através de fronteiras internacionais por turistas e imigrantes, alterações nos habitats de animais e artrópodes que transmitem doença assim como o aumento no número de pacientes com deficiências nas respostas de defesa. Os programas contínuos de vigilância de patógenos emergentes e resistência antimicrobiana são necessários para a detecção em tempo real de novos patógenos assim como para caracterizar mecanismos moleculares de resistência. Para serem mais efetivos, os programasde vigilância dos patógenos emergentes devem ser organizados em uma rede de laboratórios multicêntricos ligados aos principais centros de controle de infecções, públicos e privados. Os dados microbiológicos devem ser integrados a guias terapêuticos adaptando práticas terapêuticas à ecologia local eaos padrões de resistência. O artigo apresenta uma revisão dos dados gerados pela Disciplina de Infectologia, Universidade Federal de São Paulo, contemplando sua participação nos diferentes programas de vigilância de doenças infecciosas hospitalares e adquiridas na comunidade.

Antimicrobial susceptibility of gram-positive bacteria isolated in brazilian hospitals participating in the SENTRY Program (2005-2008)

We report the antimicrobial susceptibility patterns of the most frequently isolated Gram-positive bacteria in the Brazilian hospitals participating in the SENTRYAntimicrobial Surveillance Program. The strains were consecutively collected (one per patient) between January 2005 and September 2008 and susceptibility tested by reference broth microdilution methods at the JMI Laboratories (North Liberty, Iowa, USA). A total of 3,907 Gram-positive cocci were analyzed. The Gram-positive organisms most frequently isolated from bloodstream infections were Staphylococcus aureus (2,218 strains; 20.2 percent of total), coagulase-negative staphylococci (CoNS; 812 strains [14.7 percent]), and Enterococcus spp. (754 strains; 5.0 percent). S. aureus ranked first (28.1 percent) and Enterococcus faecalis ranked 7th (4.5 percent) among cases of skin and soft tissue infections. S. aureus was also the second most frequently isolated pathogen from patients with lower respiratory tract infections (24.9 percent of cases) after Pseudomonas aeruginosa (30.5 percent). Resistance to oxacillin was observed in 31.0 percent of S. aureus and the vast majority of oxacillin-resistant (MRSA) strains were also resistant to clindamycin, ciprofloxacin and levofloxacin. Vancomycin, linezolid and daptomycin were all very active against S. aureus strains tested (>99.9-100.0 percent susceptible), but daptomycin (MIC50, 0.25 g/mL and MIC90, 0.5 g/mL) was four- to eight-fold more potent than vancomycin (MIC50 and MIC90 of 1 g/mL) and linezolid (MIC50, 1 g/mL and MIC90, 2 g/mL). Vancomycin resistance increased significantly among enterococci during the study period, but it was restrict to only one medical center until 2007 and emerged in a second medical center in 2008. Daptomycin was the most active antimicrobial tested against enterococci in general (100.0 percent susceptible), followed by linezolid (99.9 percent susceptible), ampicillin (87.4 percent) and vancomycin (84.6 percent)...

Molecular characterization of vancomycin-resistant Enterococci strains eight years apart from its first isolation in São Paulo, Brazil / Caracterização molecular de espécies de Enterococci resistentes à vancomicina oito anos após seu primeiro isolamento em São Paulo, Brasil

E. faecium was the first reported VRE species, carrying the vanA gene in Brazil. In spite of this, vancomycin-resistant E. faecalis has become the predominant species in Brazilian hospitals. The aim of this study was to evaluate the genetic relatedness of VREs isolated in a Brazilian teaching hospital eight years apart from its first isolation. We analyzed 38 VRE strains obtained from 81 surveillance cultures of patients admitted to the four largest intensive care units in Hospital São Paulo in February, 2006. Presence of the vanA gene was assayed by PCR and PFGE analysis was used for molecular characterization. All VRE strains carried the vanA gene. Two distinct clonal groups were observed among vancomycin-resistant E. faecalis. Vancomycin-resistant E. faecium belonged to five distinct clones were demonstrated by molecular typing. All of these clones were different from the first vancomycin-resistant enterococci clone isolated eight years ago in our hospital.

E. faecium contendo o gene vanA foi a primeira espécie de VRE descrita, no Brasil. Apesar disto, E. faecalis resistente a vancomicina tem se tornado a espécie predominante nos hospitais brasileiros.O objetivo desse estudo foi avaliar a relação genética de VREs isolados em um hospital de ensino brasileiro após oito anos de seu primeiro isolamento. Analisamos 37 isolados de VRE obtidos de 81 culturas de vigilância de pacientes admitidos nas quatro maiores Unidades de Tratamento Intensivo em Fevereiro de 2006. A presença do gene vanA foi analisada por PCR e a caracterização molecular por PFGE. Todas as amostras VRE carreavam o gene vanA. Entre os E. faecalis vancomicina-resistentes, dois distintos grupos clonais foram observados. E. faecium resistente a vancomicina pertencentes a cinco clones distintos foram demonstrados por tipagem molecular. Todos esses clones foram diferentes do primeiro clone de enterococo resistente a vancomicina isolado oito anos atrás em nosso hospital.

Evaluation of the Susceptibility profiles, genetic similarity and presence of qnr gene in Escherichia coli resistant to ciprofloxacin isolated in Brazilian hospitals

Increasing quinolone resistance has been reported worldwide, mainly among clinical isolates of Escherichia coli. The objectives of this study were to determine the susceptibility profile, the genetic relatedness, and the prevalence of the qnr gene among ciprofloxacin-resistant Escherichia coli isolated from distinct Brazilian hospitals. A total of 144 ciprofloxacin-resistant Escherichia coli were isolated from 17 Brazilian hospitals between January/2002 and June/2003. The antimicrobial susceptibility testing was performed by microdilution according to NCCLS. The presence of the qnr gene was initially screened by colony blotting, and then confirmed by PCR followed by DNA sequencing. Ninety-five urinary ciprofloxacin-resistant Escherichia coli were further selected for molecular typing by pulsed-field gel electrophoresis (PFGE). Imipenem and meropenem showed the highest susceptibility rates (100.0 percent for both compounds) followed by amikacin (91.0 percent) and piperacillin/tazobactan (84.8 percent). A single ciprofloxacin-resistant Escherichia coli isolate was positive for qnr among the 144 ciprofloxacin-resistant Escherichia coli. Forty-six PFGE patterns were observed among the 95 ciprofloxacin-resistant Escherichia coli type. This study shows that therapeutic options are limited for treatment of ciprofloxacin-resistant Escherichia coli due to the presence of additional mechanisms of antimicrobial resistance, such as ESBL production. The qnr gene was uncommon among ciprofloxacin-resistant Escherichia coli clinical isolates, but its identification might indicate the emergence of this mechanism of quinolone resistance in Brazil. The great genomic variability found among the ciprofloxacin-resistant Escherichia coli highlights the importance of the appropriate use of quinolone to restrict the selection of resistant isolates.

Suscetibilidade à novobiocina na identificação de amostras de Staphylococcus coagulase negativos (SCoN) isolados de hemoculturas / Susceptibility to the novobiocin in the identification of isolates of Staphylococcus negative (SCoN) isolated from blood cultures

Tradicionalmente o Laboratório de Microbiologia Clínica utiliza a prova de suscetibilidade a novobiocina para distinguir as espécies clinicamente significativas de SCoN, entre elas o Staphylococcus saprophyticus. Devido ao aumento destes microrganismos nas infecções relacionadas à assistência à saúde, este estudo teve como objetivo relatar duas bacteremias por SCoN resistentes a novobiocina ocorridas em maio e setembro de 2006, em um hospital geral, na cidade de São Paulo. Primeiramente o teste fenotípico apontou resistência a novobiocina, mas com padrões distintos de identificação ao S. saprophyticus. Na identificação convencional, asamostras fermentaram trealose, manitol e manose, sendo positivas nos testes da urease e fosfatase alcalina. No sistema semi-automatizado, a confirmação da espécie apontou o Staphylococcus cohnii subsp. urealyticus com 99,99 de probabilidade. No teste de disco difusão, os isolados mostraram-se resistentes à oxacilina, mas suscetível a cefoxitina, vancomicina e teicoplanina. Houve confirmação pela metodologia do Etest® mostrando CIM para oxacilina superior a 256 μg/ml, e suscetibilidade a vancomicina e a teicoplanina.A reação da PCR confirmou a presença do gene mecA nos isolados. Estes dados demonstram a importância dos SCoN isolados em hemoculturas, sendo necessária uma correta identificação destes microrganismos.

Increased resistance to first-line agents among bacterial pathogens isolated from urinary tract infections in Latin America: time for local guidelines?

Emerging resistance phenotypes and antimicrobial resistance rates among pathogens recovered from community-acquired urinary tract infections (CA-UTI) is an increasing problem in specific regions, limiting therapeutic options. As part of the SENTRY Antimicrobial Surveillance Program, a total of 611 isolates were collected in 2003 from patients with CA-UTI presenting at Latin American medical centers. Each strain was tested in a central laboratory using Clinical Laboratory Standard Institute (CLSI) broth microdilution methods with appropriate controls. Escherichia coli was the leading pathogen (66 percent), followed by Klebsiella spp. (7 percent), Proteus mirabilis (6.4 percent), Enterococcus spp. (5.6 percent), and Pseudomonas aeruginosa (4.6 percent). Surprisingly high resistance rates were recorded for E. coli against first-line orally administered agents for CA-UTI, such as ampicillin (53.6 percent), TMP/SMX (40.4 percent), ciprofloxacin (21.6 percent), and gatifloxacin (17.1 percent). Decreased susceptibility rates to TMP/SMX and ciprofloxacin were also documented for Klebsiella spp. (79.1 and 81.4 percent, respectively), and P. mirabilis (71.8 and 84.6 percent, respectively). For Enterococcus spp., susceptibility rates to ampicillin, chloramphenicol, ciprofloxacin, and vancomycin were 88.2, 85.3, 55.9, and 97.1 percent, respectively. High-level resistance to gentamicin was detected in 24 percent of Enterococcus spp. Bacteria isolated from patients with CA-UTI in Latin America showed limited susceptibility to orally administered antimicrobials, especially for TMP/SMX and fluoroquinolones. Our results highlight the need for developing specific CA-UTI guidelines in geographic regions where elevated resistance to new and old compounds may influence prescribing decisions.

SENTRY antimicrobial surveillance program report: latin american and brazilian results for 1997 through 2001

The alarming emergence and spread of antimicrobial resistance among common bacteria threatens the effectiveness of therapy for many infections. Surveillance of antimicrobial resistance is essential to identify the major problems and guide adequate control measures. Several resistance surveillance programs have been implemented in North America and Europe in the last decade; however, very few programs have assessed antimicrobial resistance in Latin American countries. The SENTRY Antimicrobial Surveillance Program was initiated in 1997 and represents the most comprehensive surveillance program in place at the present time worldwide. The SENTRY Program collects consecutive isolates from clinically documented infections in more than 80 medical centers worldwide (10 in Latin America). The isolates are collected according to the type of infection (objectives) and susceptibility tested in a central microbiology laboratory by reference broth microdilution methods according to NCCLS guidelines. The Program also incorporated molecular typing (ribotyping and PFGE) and resistance mechanism analysis of selected isolates. In this report we present a very broad analysis of the data generated by testing almost 20,000 bacterial isolates against more than 30 antimicrobial agents. The susceptibility results (MIC50, MIC90 and percent susceptible) are presented in 11 tables according to the organism and site of infection. The data from Brazil, as well as the data from isolates collected in 2001, are analyzed separately. This report allows the evaluation of the activities numerous antimicrobial agents against clinical isolates collected in Latin American countries.

A respiração bucal é fator de risco para cárie e gengivite / Is mouthbreathing a risk factor to caries and gengivitis? Review

Objetivo: Revisar a literatura sobre níveis salivares de Streptococcus mutans, ocorrência de cárie dental e gengivite em pacientes respiradores bucais com dentição decídua, mista e permanente. Método: Foi realizada por busca ativa de artigos de língua inglesa indexados nas seguintes bases de dados: Medline e Lilacs. Os seguintes unitermos foram empregados: Streptococcus mutans, cárie dentária, respiração bucal, índice de placa dentária, índice periodontal. Resultados: Os níveis salivares de Streptococcus mutans apresentam-se maiores em crianças respiradoras bucais com dentição mista do que em respiradores nasais, no entanto, esta diferença não é significante em crianças com dentição decídua. A referência de cárie dental em respiradores bucais é rara. O único trabalho obtido relata que o número de superfícies com lesão de cárie inicial (mancha branca) é maior em crianças respiradoras bucais do que em respiradores nasais. Índices de placa bacteriana foram semelhantes nos grupos respiradores nasais e bucais quando analisadas dentições decíduas, mistas e permanentes, ou seja, crianças, adolescentes e adultos. Respiradores bucais apresentam maiores índices de sangramento gengival não somente na região anterior como também na região posterior. Conclusão: A respiração bucal deve ser considerada como um fator de risco para o desenvolvimento de cárie e doenças periodontais. O diagnóstico precoce, no mínimo, a partir dos três anos de idade faz-se necessário, como o estabelecimento de medidas de controle, evitando alterações nos tecidos gengivais e diminuindo o risco à doença cárie.

Phenotypic and molecular characterization of Salmonella Enteritidis strains isolated in São Paulo, Brazil

In São Paulo State, Brazil, the epidemic increase in isolation of Salmonella Enteritidis has been observed since 1994. A total of 105 S. Enteritidis strains (72 from human and 33 from non-human sources) isolated during the period 1975-1995, previously characterized by phage typing, was analyzed by antimicrobial susceptibility, plasmid profile, and ribotyping. Over 70 percent of the strains were susceptible to all antimicrobial agents tested, however, multiple resistance to antimicrobials was observed among the studied strains, mainly those from hospitalized patients. Phage type 8 (PT-8) was predominant among the strains isolated during the period of 1975-1992, but in the following years, PT-4 was the most frequent phage type identified. Seven different plasmid profiles were detected and 96 percent of the isolates harbored a plasmid of approximately 36 MDa. Ribotyping discriminated fourteen ribotypes (R1 to R14) among the strains examined. By analysis of dendrogram the strains were included in three groups with similarity level of 60 percent. The obtained results indicate that, a single ribotype (R11), determined for PT-4 strains isolated from 1993, characterizes the epidemic clone of S. Enteritidis in our region

Avaliação da eficácia de dois produtos comerciais utilizados na lavagem das mãos no hospital das clínicas / Evaluate the efficacy of two commercial products for hand washing

A presente pesquisa, realizada na enfermaria e no pronto-socorro de pediatria da Universidade Estadual de Campinas, teve como objetivo avaliar a eficácia de dois produtos comerciais utilizados no procedimento da lavagem das mãos na redução de enterobactérias presentes nas mãos dos profissionais de saúde (médicos, residentes, enfermeiros e auxiliares de enfermagem)...

Observação do comportamento dos profissionais em relação ao procedimento da lavagem das mãos no plano assistencial `a criança internada / The hand washing by the health professionals

A pesquisa, um estudo de campo, realizada na enfermaria e no pronto-socorro de pediatria de um hospital de ensino, teve como objetivo avaliar o procedimento da lavagem das mãos dos profissionais de saúde, no plano assistencial às crianças portadoras de diarréia aguda bacteriana, segundo as normas da Comissão de Controle de Indfecção Hospitalar, adotadas no Hospital das Clínicas - UNICAMP...

Tipagem de enterococcus faecalis por pulsed-field gradient gel electrophoresis e polymerase chain reaction / Typing of enterococcus faecalis by pulsed field-gradient gel electrophoresis and polymerase chain reaction

Pulsed-field gradient gel electrophoresis (PFGE) conhecido também como orthogonal-field-alternation gel electrophoresis ( OFAGE) e reação em cadeia da polimerase (PCR) foram usados para tipificar 10 amostras clínicas de Enterococcus faecalis. PFGE, empregando-se Sma I gerou 10 padrões de restrição variando de 10 para 20 fragmentos. A técnica de PCR, realizada com os primers REP-1/2R, proporcionou 7 padrões de bandas variando de 4 para 10 fragmentos. Adotando-se a seqüência repetitiva JB1- 5ÆGATTTTATGGCCGTCCGC3Æ como iniciador na reação de amplificação, foram obtidos 6 padrões de bandeamento variando de 4 para 6 fragmentos. Por PCR, os genótipos foram agrupados, contudo apenas duas amostras foram consideradas idênticas simultaneamente através das técnicas de REP-PCR e JB1-PCR. O pequeno número de amostras não possibilitou a aplicação de qualquer tratamento estatístico para se avaliar a prevalência de algum genótipo. A heterogeneidade genética das cepas foi demonstrada por PFGE e PCR. Os padrões de restrição obtidos por PFGE foram mais facilmente interpretados do que os padrões de bandeamento gerados por PCR os quais apresentaram bandas grossas, sobrepostas e de baixa nitidez. O primer JB1, empregado pela primeira vez em estudo com Enterococcus faecalis, foi útil para a diferenciação de cepas desta espécie

Evaluation of the in vitro activity of two fourth-generation cephalosporins against bacterial samples isolated from patients in several Brazilian Hospitals

Cefpirome and cefepime are two fourth-generation cephalosporins recently introduced in Brazil. They have a very similar range of in vitro antimicrobial activity, but some differences have been noticed. The goal of this study was to compare the in vitro activity of cefpirome and cefepime against bacterial samples isolated in Brazilian hospitals. We studied 931 samples taken from hospitalized patients between April and June, 1998. The minimum inhibitory concentration (MIC) was determined by the Etest method. The potency of cefpirome was similar to that of cefepime, except against enterococci and coagulase-negative staphylococci, where cefpirome proved 2-fold more potent. The MICs90 for cefepime were inferior to cefpirome in response to Klebsiella pneumoniae (MICs90, 24 and 96µg/mL, respectively), Pseudomonas aeruginosa (MICs90, 48 and 128µg/mL, respectively), and other Gram-negative organisms (MICs90, 64 and 256µg/mL, respectively). Despite the fact that cefpirome presented a slightly broader range of action against Gram-positive bacteria(90 percent sensitive vs. 78 percent sensitive to cefepime), and that cefepime presented an equally broad range against Gram-negative bacteria (74 percent sensitive vs. 65 percent sensitive to cefpirome), these differences were not considered clinically significant because the sensitivity differed in MIC by less than 2 dilutions. Only 16 (1.7 percent) of the 931 samples tested showed a significant difference in sensitivity. This study suggests that, except for Acinetobacter sp. and P. aeruginosa, laboratories may routinely test only cefpirome and apply the same category result to cefepime. Since category discrepancies are very rare and cefpirome is slightly less active than cefepime against Enterobacteriaceae, isolates susceptible to cefepime will certanly also be susceptible to cefpirome. To optimize the treatment of severely infected patients, especially where species such as Acinetobacter sp and P. aeruginosa are involved, we recommend that both cephalosporins be tested by using the same susceptibility test method to determine the MIC.

Avaliaçäo do Sistema BBL Crystal para identificaçäo de acinetobacter baumannii / Evaluation of the BBL Crystal System for the identification of acinetobacter baumanni

O Acinetobacter baumanni tem emergido como importante patógeno hospitalar nos últimos anos, especialmente em unidades de terapia intensiva. Amostras clínicas de Acinetobacter baumannii säo frequentemente resistentes a numerosos antibióticos, enquanto que outras espécies tendem a ser mais sensíveis. Portanto, a rápida identificaçäo da espécie pode ser útil para orientaçäo da terapia empírica adequada. A proposta desse estudo foi avaliar o desempenho do sistema BBL Crystal para identificaçäo de amostras de Acinetobacter baumannii. Um total de 60 amostras clínicas coletadas no Hospital Säo Paulo entre fevereiro de 1994 e fevereiro de 1995 foram analisadas pelo sistema BBL Crystal e pela metodologia convencional. O sistema estudado identificou corretamente as 60 amostras testadas, porém para identificaçäo correta de 15 amostras foi necessário recorrer ao seu banco de dados, pois o sistema recomendava a realizaçäo de provas adicionais a identificaçäo. O sistema BBL Crytal requer poucas provas adicionais (indol e oxidase) e permite a leitura após 18-20 horas de incubaçäo. Entretanto, através de seu sistema somente duas espécies de Acinetobacter (baumannii e lowffii) podem ser identificadas e algumas reaçöes (hidrólise da uréia, degradaçäo da glicina, utilizaçäo do citrato e malonato) podem apresentar dificuldades na leitura. Apesar disso, concluímos que o sistema BBL Crystal apresentou excelente desempenho para identificaçäo de amostras de A.baumannii, sendo vantajosa a sua utilizaçäo rotineira nos laboratórios pela sua praticidade

Malaria transmission associated with airplane travel

Plasmodium falciparum malaria was diagnosed in 3 patients in Säo Paulo during a 5 day period between August 31, and September 4, 1996, at a time and place where malaria transmission does not occur. After investigation of the 3 cases it was determined that the infections were acquired as a result of an international airplane flight from Lebanon to Säo Paulo on August 16, which included a 30 minute stop-over in Abidjan, Ivory Coast, Africa. During the epidemiological evaluation, it was found that each of the patients had been seated in the first class cabin. Entomological investigation at the airport revealed the presence of 4 specimens of Anopheles gambiae in airplanes (3 in the first class cabin and 1 in the luggage compartment) used on this route. The species of mosquito identified is predominant in Africa. Two of the patients were seriously ill, but all recovered after treatment with either mefloquine (1 patient) or artesunate (2 patients). A survey of other passengers on the same flight or on similar flights did not reveal any other cases of malaria. Malaria was not considered during initial evaluation by the attending physicians at the three different hospitals where in the patients were admitted. These cases reveal the existence of vector borne disease transmission during airplane travel, and emphasize the importance of obtaining a travel history during the evaluation of an ill patient. In addition, the cases reinforce the need for vigilance in the control of vector of disease around seaports, airports and hospitals.

In vitro antimicrobial activity against enterococci isolated in a university hospital in Säo Paulo, Brazil

The prevalence of multiresistant enterococci (MRE) is rapidly increasing and becoming an important problem in several countries. Säo Paulo Hospital is a 600-bed tertiary hospital located in Säo Paulo, Brazil. The use of vancomycin is very high in the hospital due to the high prevalence of multi-resistant S. aureus (around 70 percent). We susceptibillity tested 250 isolates were of Enterococci consecutively collected between March, 1994 and june, 1995. Isolates were susceptibility tested using agar dilution disc diffusion BHI screen plating, and E. test. In addition to vancomycin and teicoplanin, the isolates were tested against amplicillin, gentamicin, streptomycin and RP 59-500. Methods used for susceptibility testing were compared. None of the isolates showed high-level resistence to vancomycin or teicoplanin. The MIC9Os for teicoplanin were menor igual que 1µg/mL for E. faecalis (EF,n-216), E. faecium (EFM,n=23) and for the non-faecalis-non-faecium (NFNF,n=11) species. The MIC90s for vancomycin were 2µg/mL, 4µg/mL and 4µg/mL for EF, EFM and NFNF respectively. Eight isolates (3.2 percent), 5 E. faecalis, 2 E. caseliflavus and 1 E. gallinarum presented intermediate MICs for vancomycin (6 - 12µg/mL), but they were highly susceptible to teicoplanin (MIC0.19 - 1µg/mL). The percentage of resistence to amplicillin and high-level resistence to gentamicin and streptomycin were, respectively: 4.8 percent, 26.4 percent, and 24.8 percent. In spite of the high usage of vancomycin in our hospital, the prevalence of glycopeptide resistence among enterococci seems to be low. Teicoplanin appears to be more potent than vancomycin, RP59-500, gentamicin, streptomycin and amplicillin against this genus, especially EFM and NFNF species.

Analysis of the clonal diversity of Staphylococcus aureus methicillin-resistant strains isolated at Joäo Pessoa, state of Paraíba, Brazil

To investigate the clonal diversity of Staphylococcus aureus strains isolated at Joäo Pessoa, state of Paraíba, Brazil, digested genomic DNA were studied by pulsed-field gel electrophoresis (PFGE) in nine methicillin-resistant strains (MRSA) and three methicillin-sensitive strains (MSSA), selected among 67 isolates based on their antimicrobial susceptibility and epidemiology. The isolates were obtained between April and November 1992 from the Hospital of the Federal University of Paraíba, located in Joäo Pessoa. Two MRSA isolates from the Oswaldo Cruz Hospital, Säo Paulo, Brazil, including an epidemic strain previously detected from different hospitals at the country were used as control. Five different patterns, were demonstrated by MRSA isolated in Joäo Pessoa and these patterns were described in several epidemiologically unrelated hospitals in Säo Paulo. Our results suggest the interstate dissemination of a MRSA clone in Joäo Pessoa which is similar to that described in other cities of Brazil.

A comparaçåo das atividades antimicrobianas da cefepima e da ceftazidima em 1015 amostras bacterianas isoladas no Hospital Såo Paulo / Comparasion of the activity of cefepime and ceftazidime tested in 1015 bacterial samples isolated in Hospital Såo Paulo

O presente estudo tem como objetivo comparar a atividade in vitro de uma nova cefalospirina (4ª geraçåo), a cefepima, com a da ceftadizima. Foram testadas, através da técnica de microdiluiçåo em placa, 1015 amostras bacterianas clínicas isoladas no Hospital Såo Paulo/Escola de Medicina no período de junho a julho de 1992. Para as espécies de endobactérias de maneira geral, a concentraçåo de antimicrobianos que inibiu 50 por cento das amostras (MIC 50) variou de <0,12 a u2 g/ml tanto para a cefepima quanto para a ceftazidima. Porém, a porcentagem de amostras de Enterobacter spp. sucetíveis foi superior para a cefepima (74//versus 61 por cento). Contra as amostras de Pseudomonas aeroginosa, a ceftazidima apresentou potência pouco superior àquela demonstrada pela cefepima (MIC50s de ug/ml e 8 ug/ml respectivamente), com porcentagem de sensibilidade também superior (73 por cento versus 59 por cento). Das 569 amostras de bacilos gram-negativos avaliadas, 85 por cento foram suscetíveis à ceftdazidima e 80 por cento à cefepima. Entre os cocos garm-positivos, como os Staphylococcus aureus sensíveis à oxacilina, a cefepima (MIC90 4ug/ml) foi duas a quatro vezes mais ativa que a ceftazidima (MIC90 16ug/ml). Porém, como já era esperado, as amostras de estafilococos resistentes à oxacilina e as amostras de Enterococcus faecalis foram resistentes às duas drogas testadas, com MIC50>16ug/ml. Nesse estudo, a cefepima mostrou atividade e espectro contra gram-negativos semelhantes àquele das cefasporinas de 3ª geraçåo com atividade antipseudomonas (ceftazidima). Além disso, sua atividade contra gram-positivos foi semelhante àquela demosnstrada pelas celafosporinas de 1ª geraçåo. Apesar do avanço conquistado com as cefalosporinas de 4ª geraçåo, o uso extensivo e/ou inapropriado dessas drogas facilitará o aparecimento de cepas resistentes e a pesquisa por substâncias mais ativas deve continuar