Marinalda Anselmo Vilela

Prevalence of Staphylococcus aureus introduced into intensive care units of a University Hospital

Staphylococcus aureus is one of the principal human pathogens that colonize healthy individuals in the community in general, and it is responsible for severe infections in hospitalized patients. Due to an increase in the prevalence of strains of methicillin-resistant S. aureus (MRSA), combating these microorganisms has become increasingly difficult. A descriptive study was carried out on 231 patients in intensive care at the Oswaldo Cruz University Hospital (HUOC) in Recife, Brazil between January and April 2003 to determine the prevalence of S. aureus and MRSA and to evaluate risk factors for colonization by these bacteria when introduced into Intensive Care Units (ICUs). Body secretions were collected from the nostrils, axillary and perineal regions, and from broken skin lesions, of all patients during the first 48 hours following admission to the ICU. Samples were inoculated into blood agar and mannitol-salt-agar culture medium and identified by Gram staining, and by coagulase, DNAse and agglutination (Slidex Staph Test) tests. Growth in Mueller-Hinton agar with 4% sodium chloride and 6 mg/L oxacillin was used to identify MRSA. In addition, the latex agglutination test was performed to identify penicillin-binding protein, PBP 2A. The prevalence of S. aureus and MRSA was 87/231 (37.7%) and 30/231 (12.98%), respectively. There was no association between any risk factor studied (age, sex, origin of the patient--whether hospital or community, previous hospitalization, use of current or previous antibiotic therapy, corticotherapy and/or immunotherapy, reason for hospitalization and place of hospitalization) and the presence of S. aureus. However, a significant association was established between previous hospitalization and the presence of MRSA (RR:1.85; CI:1.00-3.41; p=0.041). The nostrils were the principal site of colonization by both S. aureus (80.4%) and MRSA (26.4%), followed by the perineal area, with rates of 27.6% and 12.6%, respectively. If only the nostrils had been investigated, the study would have failed to diagnose 17 patients (19.5%) as carriers of the pathogen into the ICU, thus contributing towards cross-dissemination.

First description of KPC-2-producing Pseudomonas putida in Brazil

ABSTRACT This work reports the identification of the first case of a KΡC-2-producing Pseudomonas putida isolate (PP36) in Brazil. The PP36 isolate was resistant to all the antimicrobials tested except polymyxin B. In addition to the discovered blaKPC-2 gene, genetic analysis showed the presence of a class 1 integron containing the dhfrXVb gene and the new allele arr-6, which codes for resistance to rifampin. These elements were found in an IncFI 65-kb plasmid.

Estudo comparativo da prevalência de Staphylococcus aureus importado para as unidades de terapia intensiva de hospital universitário, Pernambuco, Brasil

O Staphylococcus aureus e um dos principais patogenos que coloniza individuos saudaveis na comunidade e responde por infeccoes em pacientes hospitalizados. Um estudo transversal foi realizado para determinar a prevalencia de S. aureus meticilina-resistente e sensivel entre 231 pacientes, internados entre janeiro e abril de 2003, nas unidades de terapia intensiva (UTIs) do Hospital Universitario Oswaldo Cruz, assim como os possiveis fatores associados a colonizacao. Foram coletadas secrecoes de narinas, axilas, regiao perineal e dermatoses com solucoes de continuidade, de todos os pacientes, nas primeiras 48 horas de internamento nas UTIs. O material foi semeado em meios de cultura adequados. A prevalencia de S. aureus igualou-se a 37,7% (87/231), sendo 13% (30/231) meticilina-resistente e 24,8% (57/231) meticilina-sensivel. Idade, sexo, uso de antibioticoterapia, corticoterapia, motivo e local do internamento nao se associaram a presenca do S. aureus ou do meticilina-resistente. Houve associacao significante entre procedencia hospitalar e colonizacao por S. aureus, independente da cepa, e entre internamento anterior e presenca do S. aureus meticilina-resistente. As narinas foram o sitio de colonizacao mais significante, por S. aureus meticilina-resistente (47/57=82,4%) e sensivel (23/30=76,7%). Foi alta a prevalencia do S. aureus (meticilina resistente ou sensivel), assim como do meticilina-resistente entre os pacientes das UTIs deste hospital. Estudos futuros poderao comprovar se os resultados aqui descritos e medidas de rastreamento para S. aureus poderiam ser adotadas, de forma prospectiva, para se avaliar o risco, assim como a magnitude do efeito, no controle de infeccoes hospitalares provocadas por estes patogenos.

Identification and molecular characterization of Van A-type vancomycin-resistant Enterococcus faecalis in Northeast of Brazil.

The isolation of vancomycin resistant enterococci (VRE) in Brazil has rapidly increased, following the world wide tendency. We report in the present study the first isolation of vancomycin resistant Enterococcus faecalis (VRE) in the Northeast of Brazil. The four VRE isolates were characterized for antimicrobial susceptibility, genotypic typing by macro restriction of chromosomal DNA followed by pulsed-field gel electrophoresis and for characterization of the Tn1546-like element and plasmid contents. The isolates showed resistance to multiple antibiotics and a single genotype profile, suggesting the dissemination of a single clone among the patients. Tn1546 associated to genetic elements as plasmids shows the importance of infection control measures to avoid the spreading of glycopeptide resistance by conjugative transfer of VanA elements.

Changing the epidemiology of carbapenem-resistant Pseudomonas aeruginosa in a Brazilian teaching hospital: the replacement of São Paulo metallo-β-lactamase-producing isolates

In Brazil, carbapenem-resistant Pseudomonas aeruginosa isolates are closely related to the São Paulo metallo-β-lactamase (SPM) Brazilian clone. In this study, imipenem-resistant isolates were divided in two sets, 2002/2003 and 2008/2009, analysed by pulsed field gel electrophoresis and tested for the Ambler class B metallo-β-lactamase (MBL) genes blaSPM-1, blaIMP and blaVIM. The results show a prevalence of one clone related to the SPM Brazilian clone in 2002/2003. In 2008/2009, P. aeruginosa isolates were mostly MBL negative, genetically diverse and unrelated to those that had been detected earlier. These findings suggest that the resistance to carbapenems by these recent P. aeruginosa isolates was not due to the spread of MBL-positive SPM-related clones, as often observed in Brazilian hospitals.

First Description of KPC-2-Producing Klebsiella oxytoca in Brazil

ABSTRACT The present work reports the detection of the first case of nosocomial Klebsiella oxytoca producing class A carbapenemase KPC-2 in Brazil. The isolate KPN106 carried a 65-kb IncW-type plasmid that harbors the blaKPC gene and Tn4401b. Moreover, we detected the presence of a class 1 integron containing a new allele, arr-8, followed by a 5′-truncated dhfrIIIc gene. In view of the recent results, we emphasize the high variability of the bacterial and genetic hosts of this resistance determinant.

Emergence of extensively drug-resistant OXA-72-producing Acinetobacter baumannii in Recife, Brazil: risk of clonal dissemination?

Two new examples of OXA-72-producing Acinetobacter baumannii isolate resistant to a broad spectrum of antimicrobials, but not polymyxin B, have been identified in Recife, Brazil. Molecular typing indicated a close genetic link with the OXA-72-producing A. baumannii previously isolated in São Paulo, suggesting the possibility of clonal dissemination within the country.

Clonal spread of carbapenem-resistant Serratia marcescens isolates sharing an IncK plasmid containing blaKPC-2.

Univ Fed Pernambuco, Lab Resistencia Microbiana, Inst Ciencias Biol, BR-50100130 Recife, PE, Brazil

Coproduction of KPC-2 and QnrB19 in Klebsiella pneumoniae ST340 isolate in Brazil

Few reports described the presence of bla(KPC) and qnr genes in the same isolate. This study reports the combination of bla(KPC-2) and qnrB19 genes in Klebsiella pneumoniae ST340 isolate in Brazil. These findings draw attention to this combination in ST340 isolate, which is part of the CC258, disseminated in Latin America.

Colistin-resistant KPC-2-producing Klebsiella pneumoniae ST423 harboring an IS5-like element in the mgrB gene isolated from cerebrospinal fluid

We describe colistin-resistant KPC-2-producing Klebsiella pneumoniae isolates from cerebrospinal fluid, belonging to ST423, selected during treatment for neuroinfection. Colistin resistance was related to mgrB gene interruption by an IS5-like.