Genome Mining for Antimicrobial Compounds in Wild Marine Animals-Associated Enterococci.

New ecosystems are being actively mined for new bioactive compounds. Because of the large amount of unexplored biodiversity, bacteria from marine environments are especially promising. Further, host-associated microbes are of special interest because of their low toxicity and compatibility with host health. Here, we identified and characterized biosynthetic gene clusters encoding antimicrobial compounds in host-associated enterococci recovered from fecal samples of wild marine animals remote from human-affected ecosystems. Putative biosynthetic gene clusters in the genomes of 22 Enterococcus strains of marine origin were predicted using antiSMASH5 and Bagel4 bioinformatic software. At least one gene cluster encoding a putative bioactive compound precursor was identified in each genome. Collectively, 73 putative antimicrobial compounds were identified, including 61 bacteriocins (83.56%), 10 terpenes (13.70%), and 2 (2.74%) related to putative nonribosomal peptides (NRPs). Two of the species studied, Enterococcus avium and Enterococcus mundtti, are rare causes of human disease and were found to lack any known pathogenic determinants but yet possessed bacteriocin biosynthetic genes, suggesting possible additional utility as probiotics. Wild marine animal-associated enterococci from human-remote ecosystems provide a potentially rich source for new antimicrobial compounds of therapeutic and industrial value and potential probiotic application.

Identifying pneumococci in parapneumonic pleural effusion: Is there a role for culture-independent methods?

OBJECTIVE: To evaluate culture-independent procedures (immunochromatography and quantitative polymerase chain reaction [qPCR]) in the detection and susceptibility of Streptococcus pneumoniae directly from culture-negative pleural fluid (PF) in children. METHOD: Detection of S. pneumoniae in PF of children with parapneumonic effusion and/or empyema by using two culture-independent methods: an immunochromatographic membrane test (IMT) which identifies the pneumococcal C antigen, and a real-time PCR test to detect pneumococcal genes lytA and pbp2b, a marker of susceptibility of ß-lactam agents, in PF samples. RESULTS: We tested 36 PF specimens and recorded the previous use of antimicrobials. In the final analysis, 34 samples were included. IMT and qPCR presented positive results in 23 (67.6%) and 24 (70.6%) of the samples, respectively, showing a moderate agreement (k = 0.518) between the two methods. From the 36 children included, 34 (94.4%) had antibiotic data available by the time when PFs were collected. Thirty-four (100%) children had been given treatment before PF sampling, with 33 (97%) receiving ß-lactam antibiotics administered empirically. Of the 24 lytA real-time positive samples, 21 (87.5%) were also positive for pbp2b, a marker of ß-lactam susceptibility. CONCLUSION: The reduced sensitivity of culture for pneumococcal detection can be improved through the addition of IMT and qPCR analysis. The utility of qPCR combining detection of lytA and a marker of ß-lactam susceptibility should be explored further.

Draft Genome Sequence of Enterococcus faecalis Strain F165 Isolated from a Urinary Tract Infection.

We report here a draft genome sequence of Enterococcus faecalis strain F165 isolated from a urine specimen in South Brazil. The genome size was 3,049,734 bp, with a G+C content of 37.38%, and genes related to antimicrobial resistance and adherence were found in the strain. These findings are consistent with pathogenesis of E. faecalis species.

Draft Genome Sequence of Brazilian Escherichia coli Uropathogenic Strain E2.

Escherichia coli is a common pathogen recovered from cystitis infections. In this report, we announce the draft genome sequence of strain E2 isolated from the urine specimen from a female patient in South Brazil. The genome assembly has 5,081,209 bp, a G+C content of 50.57%, and virulence factors associated with both enteroaggregative and uropathogenic E. coli strains.

Multidrug-resistant Staphylococcus spp and its impact on patient outcome.

In order to analyze the outcomes, clinical features, and resistance of Staphylococcus spp infections, a prospective cohort study was conducted at a 234-bed, tertiary care teaching hospital. Multidrug-resistant (MDR) infections were associated with increased mortality and length of hospital stay (LOS), whereas methicillin resistance (MRS) was correlated with prolonged LOS after infection. These data highlight the importance of infection control and antibiotic stewardship to prevent the emergence and spread of MRS and MDR health care-associated infections.

Characterization of the faecal bacterial community of wild young South American (Arctocephalus australis) and Subantarctic fur seals (Arctocephalus tropicalis).

The microbiota of wild marine mammals is poorly understood, perhaps due to the migratory habits of some species and the difficulty in obtaining samples. Using high-throughput sequencing, the present study examines the faecal bacterial community of wild young South American (Arctocephalus australis) and Subantarctic fur seals (A. tropicalis). Faecal samples from South American (n = 6) and Subantarctic fur seals (n = 4) found dead along the south coast of Brazil were collected. Sequences were assigned to taxa using the Ribosomal Database Project-Bayesian classifier. Diversity of the microbiota was assessed by categorization of sequence reads into operational taxonomic units. Results indicate that Firmicutes (88.556%-84.016%) was the predominant phylum in South American and Subantarctic fur seals. The distribution of Actinobacteria and Proteobacteria varied according to the fur seal species. Fusobacteria and Bacteroidetes represented less than 1% of the sequences. The most abundant order in both fur seals was Clostridiales (88.64% and 87.49%). Individual variable incidences were observed in the composition of family among the fur seals, though the families Lachnospiraceae, Peptostreptococcaceae, Ruminococcaceae and Coriobacteriaceae were more prevalent. This study provides insight into the faecal bacterial community of wild young South American and Subantarctic fur seals.

MRSA from Santa Catarina State, Southern Brazil: intriguing epidemiological differences compared to other Brazilian regions

Methicillin-resistant Staphylococcus aureus(MRSA) is one of the most frequently isolated agents in both nosocomial and community settings. It is a constant challenge for antibacterial therapy. Therefore, it becomes essential to understand the epidemiology of MRSA isolates in the institution and/or region to guide empirical therapy. The objective of this study was to evaluate the epidemiological characteristics of MRSA isolates in the state of Santa Catarina, Brazil, and determine if there is a clonal spread. We evaluated 124 clinical isolates of MRSA obtained from various anatomical sites from patients in the state of Santa Catarina in Southern Brazil. The antimicrobial susceptibility profile was evaluated by disk diffusion and minimum inhibitory concentration (MIC) was determined by Etest and broth macrodilution. SCCmectypes were determined by multiplex PCR and the clonal relationship among isolates was assessed by pulsed field gel electrophoresis. Antimicrobials that have demonstrated lower rates of resistance were tetracycline (20.2%), sulfamethoxazole-trimethoprim (20.2%) and chloramphenicol (12.9%). We did not detect any resistance to glycopeptides, daptomycin, linezolid, and tigecycline. SCCmectype III was predominant (54%), followed by type II (21.8%), consistent with other Brazilian studies. Twenty-six clones were observed grouping 72 (58%) isolates and no clonal relationship was observed between our isolates and the major epidemic clones circulating in Brazil. An intriguing distinct MRSA epidemiology was observed in Santa Catarina, compared to other Brazilian regions.

MRSA from Santa Catarina State, Southern Brazil: intriguing epidemiological differences compared to other Brazilian regions.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most frequently isolated agents in both nosocomial and community settings. It is a constant challenge for antibacterial therapy. Therefore, it becomes essential to understand the epidemiology of MRSA isolates in the institution and/or region to guide empirical therapy. The objective of this study was to evaluate the epidemiological characteristics of MRSA isolates in the state of Santa Catarina, Brazil, and determine if there is a clonal spread. We evaluated 124 clinical isolates of MRSA obtained from various anatomical sites from patients in the state of Santa Catarina in Southern Brazil. The antimicrobial susceptibility profile was evaluated by disk diffusion and minimum inhibitory concentration (MIC) was determined by Etest and broth macrodilution. SCCmec types were determined by multiplex PCR and the clonal relationship among isolates was assessed by pulsed field gel electrophoresis. Antimicrobials that have demonstrated lower rates of resistance were tetracycline (20.2%), sulfamethoxazole-trimethoprim (20.2%) and chloramphenicol (12.9%). We did not detect any resistance to glycopeptides, daptomycin, linezolid, and tigecycline. SCCmec type III was predominant (54%), followed by type II (21.8%), consistent with other Brazilian studies. Twenty-six clones were observed grouping 72 (58%) isolates and no clonal relationship was observed between our isolates and the major epidemic clones circulating in Brazil. An intriguing distinct MRSA epidemiology was observed in Santa Catarina, compared to other Brazilian regions.

Prevalence of community-acquired methicillin-resistant Staphylococcus aureus and antibiotic resistance in patients with atopic dermatitis in Porto Alegre, Brazil.

BACKGROUND: Atopic dermatitis (AD) is a skin manifestation of atopy caused by hyperreactivity to various antigens. Studies have shown that 60-100% of patients with this condition present with colonization by Staphylococcus aureus. Given increasing rates of antimicrobial resistance, the sensitivity to antimicrobials of S. aureus colonizing atopic patients has been investigated. Cross-sectional studies worldwide suggest that the prevalence of methicillin-resistant S. aureus infection (MRSA) in the AD population varies from 0% to 30.8%. OBJECTIVES: The objectives of this study were to determinate the prevalence of S. aureus and MRSA in patients with AD in two dermatologic centers in Porto Alegre, Brazil. METHODS: A total of 91 patients with AD attending two dermatologic centers in Porto Alegre were enrolled in this study from December 2009 to July 2011. Two skin swabs were taken from each patient, one from the nares and the other from a non-infected eczematous skin lesion. The swabs were sent to the laboratory, where standard procedures to isolate bacteria and identify S. aureus, antimicrobial resistance, and sensitivity patterns were carried out. The severity of AD was defined using the Eczema Area and Severity Index (EASI). RESULTS: Of the 91 patients sampled, 67 (73.6%) patients were found to be positive for S. aureus colonization. Nasal swabs were positive in 55 (60.4%) patients, lesional swabs in 44 (48.4%) patients, and both lesional and nasal swabs were positive in 32 (35.2%) patients. Patients with positive swabs had a higher mean ± standard deviation EASI score [mean (9.1 ± 8.8)] compared with patients with negative swabs (3.9 ± 3.6) (P = 0.002). None of the 91 patients showed any evidence of MRSA infection. Overall, nearly 32% of the S. aureus isolated from nasal swabs and 36.40% of the S. aureus isolated from lesional swabs was resistant to erythromycin. CONCLUSIONS: The results of this study confirm a high rate of S. aureus colonization in pediatric patients with AD and indicate a relevant association between colonization and high EASI score. No MRSA was found in cultures from this sample of patients in southern Brazil. Nearly one-third of isolates were identified as resistant to erythromycin, an antibiotic that is commonly used in pediatric patients.

Virulência e formação de biofilme microbiano por Enterococcus faecalis isolados de swabs cloacais de frangos de corte infectados com Eimeria spp / Virulence and biofilm formation by Enterococcus faecalis isolates from cloacal swabs of broilers infected with Eimeria spp

A dinâmica da microbiota no trato gastrointestinal (TG) de animais pode ser afetada por patógenos, tais como Eimeria spp. Os enterococos são bactérias saprófitas que colonizam o TG de mamíferos e aves. A influência sobre a microbiota intestinal está relacionada com a capacidade de adaptação das bactérias em se aderir às células hospedeiras e de colonizar as células das mucosas. O objetivo deste estudo foi analisar a frequência de genes de virulência ace, agg e operon do bopABCD em Enterococcus faecalis isolados de swabs cloacais de frangos de corte desafiados com Eimeria spp e alimentados com dietas padrões suplementadas ou não com anticoccidiano (monesina) e também avaliar a capacidade dessas cepas em formar biofilmes sob condições in vitro. Um total de 70 E. faecalis foram selecionadas e o gene agg foi mais freqüente em cepas isoladas de frangos de corte alimentados com anticoccidiano (92,3%) quando comparado ao grupo que não recebeu anticoccidiano (70,5%). Por outro lado, os genes ace e do operon bopABCD não demostraram nenhuma diferença significativa entre os dois grupos de frangos (P>0,005). Os E. faecalis isolados de frangos de corte alimentados com anticoccidiano demostraram uma maior frequência de fortes aderentes quando crescendo em meio suplementado com glicose (92,3-88,5%) e urina (77%), quando comparado com enterococos isolados de frangos que não receberam anticoccidiano. Observou-se que E. faecalis isolados de frangos tratados com anticoccidiano mostraram uma maior frequêencia dos genes dos fatores de virulência e de perfil de fortes formadores de biofilme, o que indica uma melhor adaptação dos isolados em ambiente intestinal saudável.

The microbiota dynamics in the gastrointestinal tract (GT) of animals can be disrupted by pathogens, such as Eimeria spp. Enterococci are saprophytic bacteria that colonize the GT of mammals and birds. The influence on the intestinal microbiota is related to the adaptive capacity of bacteria to adhere to host cells and colonize the mucosal cells. The aim of this study was to analyze the frequency of virulence genes ace, agg and bopABCD operon in Enterococcus faecalis isolated from cloacal swabs of broilers challenged with Eimeria spp. and fed with a standard diet supplemented or not with anticoccidial (monensin), and, also to evaluate for the ability of these strains to form biofilms under in vitro conditions. A total of 70 E. faecalis were selected and the agg gene was more frequent in strains isolated from the broilers treated with anticoccidial (92.3%) when compared to the group that not received anticoccidial (70.5%). On the other hand, the ace and bopABCD operon genes showed no significant difference between the two groups of broilers (P>0.005). The E. faecalis isolated from the broilers treated with anticoccidial showed a higher frequency of strong biofilm formation when growing in medium supplemented with glucose (92.3-88.5%) and urine (77%) when compared with enterococci isolated from broilers that not received anticoccidial. It was observed that E. faecalis isolated from broilers treated with anticoccidial showed a higher frequency of virulence factors genes and stronger biofilms formation, indicating better adaptation of the isolates in healthy intestinal environment.

Multilocus sequence typing and further genetic characterization of the enigmatic pathogen, Staphylococcus hominis.

Staphylococcus hominis is a commensal resident of human skin and an opportunistic pathogen. The species is subdivided into two subspecies, S. hominis subsp. hominis and S. hominis subsp. novobiosepticus, which are difficult to distinguish. To investigate the evolution and epidemiology of S. hominis, a total of 108 isolates collected from 10 countries over 40 years were characterized by classical phenotypic methods and genetic methods. One nonsynonymous mutation in gyrB, scored with a novel SNP typing assay, had a perfect association with the novobiocin-resistant phenotype. A multilocus sequence typing (MLST) scheme was developed from six housekeeping gene fragments, and revealed relatively high levels of genetic diversity and a significant impact of recombination on S. hominis population structure. Among the 40 sequence types (STs) identified by MLST, three STs (ST2, ST16 and ST23) were S. hominis subsp. novobiosepticus, and they distinguished between isolates from different outbreaks, whereas 37 other STs were S. hominis subsp. hominis, one of which was widely disseminated (ST1). A modified PCR assay was developed to detect the presence of ccrAB4 from the SCCmec genetic element. S. hominis subsp. novobiosepticus isolates were oxacillin-resistant and carriers of specific components of SCCmec (mecA class A, ccrAB3, ccrAB4, ccrC), whereas S. hominis subsp. hominis included both oxacillin-sensitive and -resistant isolates and a more diverse array of SCCmec components. Surprisingly, phylogenetic analyses indicated that S. hominis subsp. novobiosepticus may be a polyphyletic and, hence, artificial taxon. In summary, these results revealed the genetic diversity of S. hominis, the identities of outbreak-causing clones, and the evolutionary relationships between subspecies and clones. The pathogenic lifestyle attributed to S. hominis subsp. novobiosepticus may have originated on more than one occasion.

Prevalência de resistência bacteriana nas infecções de ferida operatória causadas por estafilococos em cirurgia vascular periférica / Prevalence of bacterial resistance in wound infections caused by staphylococci in peripheral vascular surgery

Introdução: A infecção de sítio cirúrgico é uma complicação grave da cirurgia vascular periférica. O recente aparecimento de estafilococos resistentes e agressivos gera uma nova preocupação com relação ao manejo e prevenção dessas infecções. O objetivo deste estudo é verificar a prevalência de resistência bacteriana estafilocócica, padrão de resistência bacteriana, a epidemiologia e possíveis fatores associados. Métodos: Pacientes submetidos a cirurgia arterial periférica no período de março de 2007 a março de 2008 que desenvolveram infecção da ferida operatória. Foram analisados 25 casos de pacientes portadores de infecção de ferida operatória causada por estafilococo. Os fatores estudados foram a presença de resistência bacteriana, idade, sexo, comorbidades, tempo de internação pré-operatória, profilaxia antimicrobiana, tipo de cirurgia, utilização de prótese, topografia da infecção, classificação da infecção. Resultados: Média de idade de 64,4 anos, 76% do sexo masculino. Prevalência geral de resistência bacteriana de 68%. O patógeno mais isolado foi o Staphylococcus aureus (64%), sendo 11 de 16 culturas (68,7%) resistentes à oxacilina. O padrão da resistência aos antimicrobianos foi: oxacilina 68%~ clindamicina, sulfametoxazol e eritromicina 64%. Todos os micro-organismos testados foram sensíveis à vancomicina. Conclusões: A resistência bacteriana é um achado frequente nas infecções de ferida operatória em cirurgia vascular periférica. O micro-organismo mais isolado é o Staphylococcus aureus, que demonstrou elevadas taxas de resistência aos antimicrobianos. A vancomicina permanece como a melhor alternativa para tratamento dessas infecções

Introduction: Surgical site infection is a serious complication of peripheral vascular surgery. The recent emergence of resistant and aggressive staphylococci raises a new concern as for the management and prevention of these infections. The aim of this study is to assess the prevalence of bacterial resistance to staphylococcal infection, pattern of bacterial resistance, epidemiology and associated factors. Methods: Patients who underwent peripheral arterial surgery in the period from March 2007 to March 2008 who developed wound infection. We analyzed 25 cases of patients with wound infection caused by staphylococci. The factors studied were the presence of bacterial resistance, age, sex, comorbidities, length of preoperative hospitalization, antimicrobial prophylaxis, type of surgery, use of prosthesis, infection topography, and classification of infection. Results: Average age was 64.4 years, 76% males. The overall prevalence of bacterial resistance was 68%. The most frequently isolated pathogen was Staphylococcus aureus (64%), and 11 of 16 cultures (68.7%) were resistant to oxacillin. The pattern of antimicrobial resistance was: 68% oxacillin, clindamycin, sulfamethoxazole and erythromycin 64%. All microorganisms tested were sensitive to vancomycin. Conclusions: Bacterial resistance is a common finding in surgical wound infections in peripheral vascular surgery. The most frequently isolated microorganism is Staphylococcus aureus, which showed high rates of antimicrobial resistance. Vancomycin remains the best alternative for treating these infections

Staphylococcus hominis subsp. novobiosepticus strains causing nosocomial bloodstream infection in Brazil.

OBJECTIVES: To report the isolation of six Staphylococcus hominis subsp. novobiosepticus (SHN) strains from hospitalized patients with bloodstream infections in two Brazilian hospitals and to characterize their susceptibility profile to several antimicrobials. METHODS: Species identification was performed by biochemical methods and sodA gene sequencing. The MICs of antimicrobials were determined by broth and agar dilution methods and by Etest. Isolates were typed by PFGE and PCR amplification was used to detect the ccr gene complex and the mec class. Morphometric evaluation of cell wall was performed by transmission electron microscopy (TEM). RESULTS: Susceptibility profiles indicated that the majority of isolates (five) were multidrug-resistant. Overlapping and multiplex PCR showed that five out of the six strains harboured SCCmec type III with class A mec and type 3 ccr. The initial vancomycin MIC value of 4 mg/L for these strains increased to 16-32 mg/L after growth for 10 days in BHI broth supplemented with this antimicrobial. TEM indicated that vancomycin resistance was associated with cell wall thickening and to another mechanism not fully elucidated. Only one SHN strain was oxacillin- and vancomycin-susceptible. The nosocomial infections in at least five of the patients from both hospitals were caused by a single clone of SHN. CONCLUSIONS: It is very important to consider SHN strains as the cause of nosocomial infections. The clinical implications resulting from the pattern of multidrug resistance in these strains may be complicated by the emergence of vancomycin resistance.

Prevalência de resistência bacteriana nas infecções de ferida operatória em cirurgia arterial periférica / Prevalence of bacterial resistance in surgical wound infections in peripheral arterial surgery

CONTEXTO: A infecção de sítio cirúrgico é uma complicação grave da cirurgia vascular periférica. O recente aparecimento de microorganismos resistentes e agressivos gera uma nova preocupação com relação ao manejo dessas infecções. OBJETIVO: Verificar a prevalência de resistência bacteriana, a epidemiologia, os possíveis fatores associados e o padrão de resistência nas infecções de ferida operatória das cirurgias arteriais periféricas. MÉTODOS: Estudo de prevalência, envolvendo 40 pacientes portadores de infecção da ferida operatória e submetidos à cirurgia de revascularização arterial periférica no período de janeiro de 2007 a maio de 2008. RESULTADOS: Participaram do estudo pacientes com média de idade de 64,2 anos, predominantemente do sexo masculino (70%). A prevalência geral de resistência bacteriana foi 72,5%, e de multirresistência, 60%. O microorganismo mais freqüentemente isolado foi o Staphylococcus aureus (40%), sendo 11 das 16 culturas (68,7%) resistentes à oxacilina. As taxas de resistência aos principais antimicrobianos testados foram: ampicilina, 85,7%; cefalosporina, 76,9%; oxacilina, 65%; e ciprofloxacina, 62,5%. Não foi identificada resistência à vancomicina e ao imipenem. CONCLUSÕES: Os achados deste estudo sugerem que a resistência bacteriana é um problema atual e muito prevalente nas cirurgias arteriais periféricas. O Staphylococcus aureus segue sendo o principal patógeno envolvido, demonstrando altas taxas de resistência. A vancomicina e o imipenem seguem sendo as principais opções terapêuticas para esse tipo de infecção.

BACKGROUND: Surgical wound infection is a severe complication of peripheral vascular surgery. The recent appearance of resistant and aggressive pathogens brings new concerns related to the management of these infections. OBJECTIVE: To verify the prevalence of bacterial resistance, epidemiology, possibly associated factors and resistance patterns in wound infections of peripheral arterial surgeries. METHODS: Prevalence study of 40 patients with surgical wound infections submitted to peripheral arterial revascularization procedures between January 2007 and May 2008. RESULTS: Mean age was 64.2 years, males represented 70% of all cases. The overall prevalence of bacterial resistance was 72.5% and multiresistance 60%. The commonest single cultured microorganism was the Staphylococcus aureus (40%), and 11 of 16 cultures (68.7%) were oxacillin-resistant. Prevalence of resistance to the main tested antibiotics: ampicillin 85.7%; cephalosporin 76.9%; oxacillin 65%; and ciprofloxacin 62.5%. Resistance to vancomycin and imipenem was not identified. CONCLUSIONS: The findings of this study suggest that bacterial resistance is a prevalent and current problem in peripheral vascular surgeries. Staphylococcus aureus is still the most frequently involved pathogen, showing high resistance rates. Vancomycin and imipenem are still the best therapeutic options to treat these infections.

Profilaxia antimicrobiana em cirurgia vascular periférica: cefalosporina ainda é o padrão-ouro?: [revisão] / Antimicrobial prophylaxis in peripheral vascular surgery: is cephalosporin still the gold standard?: [review] / Antimicrobial prophylaxis in peripheral vascular surgery: is cephalosporin still the gold standard?: [review]

Nas cirurgias vasculares periféricas, as cefalosporinas têm seu uso consagrado como agente antimicrobiano profilático de escolha. Recentemente, observamos uma mudança nos padrões de colonização, prevalência de patógenos e suscetibilidade geral aos antimicrobianos. Os patógenos multirresistentes vêm se tornando cada vez mais freqüentes nas infecções de ferida cirúrgica vascular, demonstrando variações regionais e locais quanto à suscetibilidade aos antimicrobianos profiláticos utilizados na rotina cirúrgica. Os dados e a literatura disponível até o momento demonstram que não existe evidência suficiente para uma mudança na rotina profilática perioperatória. Entretanto, devemos levar em consideração os padrões regionais e institucionais de prevalência de patógenos resistentes e padrões de suscetibilidade aos antimicrobianos para estabelecer guias e orientações específicas para a utilização de antimicrobianos profiláticos alternativos.

In peripheral vascular surgery, cephalosporins are nowadays regarded as the first choice for operative antibiotic prophylaxis. We have recently observed changes in colonizing patterns, pathogen prevalence and antibiotic susceptibility to antimicrobials. Multiresistant pathogens are becoming more frequent in vascular surgical wound infections, showing regional and local variations as to prophylactic antibiotic susceptibility. Data from the available literature so far have shown no strong evidence for a change in routine surgical antibiotic prophylaxis. We must consider regional and institutional prevalence of pathogen resistance and patterns of antibiotic susceptibility to establish specific guidelines for the use of alternative antibiotics.

Diversity of mutations in the atpC gene coding for the c Subunit of F0F1 ATPase in clinical isolates of optochin-resistant Streptococcus pneumoniae from Brazil.

We report the characteristics of four optochin-resistant (Opt(r)) Streptococcus pneumoniae isolates from Brazil. All four Opt(r) isolates presented mutations in the nucleotide sequence coding for the c subunit of F(0)F(1) ATPase. Two isolates showed mutations in codons 23 (leading to the deduced amino acid substitution isoleucine instead of alanine) and 49 (serine instead of alanine, a novel type of mutation detected at this position), respectively. Two additional novel mutations, both located in codon 45, were detected in the other two isolates, corresponding to leucine or valine (instead of phenylalanine). The data indicate that three previously unrecognized alterations were detected in the atpC gene of S. pneumoniae and that Opt resistance among Brazilian pneumococcal isolates is not related to a specific pneumococcal serotype, antimicrobial-resistance profile, or clonal group.

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.

Evaluation of phenotypic methods for methicillin resistance characterization in coagulase-negative staphylococci (CNS).

Coagulase-negative staphylococci (CNS) are the major cause of nosocomial infections. Methicillin-resistant strains are particularly important because they narrow therapeutic options. Detecting methicillin resistance among CNS has been a challenge for years. The objective of this study was to determine the accuracy of an agar screening test (0.6 and 4 microg oxacillin ml(-1)), disc diffusion and the automated MicroScan system to characterize methicillin resistance among CNS. One hundred and seventy five strains were analysed: 41.1 % Staphylococcus epidermidis and 59.9 % other species; 69.1 % were mecA-positive. The results showed that the methods have optimal correlation with the detection of mecA gene for S. epidermidis, Staphylococcus hominis and Staphylococcus haemolyticus. However, accuracy of the tests is impaired when less common species are analysed. The only 100 % accurate test was agar screening with 4 microg oxacillin ml(-1).