Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was first reported in remote indigenous communities living in the sparsely populated Kimberley region of Western Australia (WA). Between 1989 and 1995 five Panton Valentine leucocidin (PVL) negative clones were isolated from these communities: ST1-MRSA-IVa [2B] (WA-MRSA-1), ST78-MRSA-IVa [2B] (WA-MRSA-2), ST5- MRSA-IVa [2B] (WA-MRSA-3), ST45-MRSA-V [5C2] (WA-MRSA-4), and ST8- MRSA-IVa [2B] (WA-MRSA-5).Between 1995 and 2003, S. aureus screening of the indigenous populations living in 11 of these remote communities showed the S. aureus population consisted of 13 multilocus sequence type clonal complexes (CCs) and two Singleton lineages. Although five lineages contained MRSA, the MRSA lineages were not the predominant methicillin-susceptible S. aureus (MSSA) lineages. There was greater diversity amongst the MSSA, while the MRSA appeared to have emerged clonally following acquisition of the staphylococcal cassette chromosome mec (SCCmec) element. The emergence of CA-MRSA clones in different CCs indicates horizontal transmission of the SCCmec element into S. aureus had occurred on at least six occasions: SCCmec IVa [2B] into CC1 (ST1), CC5 (ST5), CC8 (ST8), CC45 (ST45), CC88 (ST78) and SCCmec V [5C2] into CC45 (ST45). Based upon the spa type and the DNA microarray profile six evolutionary events have subsequently occurred on at least three occasions from these clones (i.e. vertical transmission of the SCCmec element): twice from WA-MRSA-1, WA-MRSA-3, and WA-MRSA-5. Vertical transmission of the SCCmec element has not been identified for WA-MRSA-4 or WA-MRSA-2. The most prevalent MSSA lineage in the communities was the PVLpositive Singleton ST93 clone. As ST93-MRSA-IVa [2B], colloquially known as Queensland CA-MRSA, has become the most prevalent CA-MRSA in Australia, it was surprising in an environment of high β-lactam use and frequent horizontal transmission of SCCmec IVa a methicillin-resistant variant of ST93-MSSA was not found.Within these indigenous communities people colonised with MSSA tended to harbour clones of a different genetic lineage at each anatomical site while people colonised with MRSA tended to harbour clones of the same lineage at each site. Although the anterior nares is the preferred screening site for population studies, in this study many isolates of S. aureus would have been missed if throat and skin lesions had not also been swabbed. Three MRSA clones (WA-MRSA-1, WAMRSA- 2, and WA-MRSA-3) considered to be endemic in these communities have subsequently become predominant clones in the wider Australian community.Although WA-MRSA-1, WA-MRSA-2, WA-MRSA-3 and Queensland CA-MRSA predominate, the CA-MRSA population in Australia is genetically diverse. In WA, between 2003 and 2010, 83 unique pulsed-field gel electrophoresis (PFGE) strains were described from which 46 multilocus sequence types have been characterised. Forty five of these sequence types (STs) were from 18 CCs and two Singletons. While SCCmec IV and V were the…

Bacterial resistance is one of the worldwide public health issues. This work aimed to genetically characterize species of the family Enterobacteriaceae phenotipic producing ESBL and KPC obtained from patients of Alagoas. Bacteria were identified by semi-automated tests. Confirmed as producing ESBL and KPC by phenotypic screening tests. The antimicrobial in vitro susceptibility test was performed by disk-diffusion method. DNA was extracted by boiling method at 95ºC. The resistance genes blaTEM, blaCTX-M, blaSHV e blaKPC were identified with specific primers and genetic typing was performed by PCR with the microsatellite (GTG)5. 254 isolates of enterobacteria were obtained, of which 92,12% (234/254) had some of the genes blaTEM, blaCTX-M, blaSHV or blaKPC, 87,18% (204/234) ESBL (blaTEM, blaCTX-M, blaSHV) and 12,82% (30/234) KPC (blaKPC). Of these 234 isolates, 4,7% (11/234) were community-acquired infections with genes that express ESBL and 95,3% (223/234) of hospital infections, of which 86,55% (193/223) ESBL and 13,45% (30/223) KPC. BlaCTX-M (> 80%) was the most frequent type gene in enterobacteria. Urinary infections were the most frequent cases of infection in the community by Escherichia coli (54,55%) and Klebsiella pneumoniae (39,46%) in the hospital. BlaKPC was identified only in bacteria of hospital infections, especially in K. pneumoniae (30%). At the ICUs (38,57%) were obtained the most number of isolates producing ESBL and KPC. These enterobacteria showed multidrug resistance phenotypes with high levels for aminoglycosides, fluoroquinolones and sulfamethoxazole/trimethoprim. Associations between genotypes and antibiotic resistance were observed. Cases of clonal spread were identified in the hospital of Alagoas by enterobacteria producing ESBL and KPC. There is a predominance of genes blaTEM, blaCTX-M, blaSHV and blaKPC among isolates of enterobacteria resistant to beta-lactam, with the prevalence of the genetic element blaCTX-M. The clonal spread have contributed to the high levels of beta-lactam resistance among isolates of enterobacteria at hospitals in this study.

Fundação de Amparo a Pesquisa do Estado de Alagoas

A resistência bacteriana representa um dos problemas mundiais de saúde pública. Este trabalho teve como objetivo caracterizar geneticamente espécies da família Enterobacteriaceae produtoras fenotípicas de ESBL e KPC obtidas de pacientes de Alagoas. As bactérias foram identificadas por testes semi-automatizados. Confirmadas como produtoras de ESBL e KPC por testes fenotípicos de triagem. O teste de susceptibilidade in vitro aos antimicrobianos foi realizado pelo método de disco-difusão. O DNA foi extraído pelo método de fervura à 95ºC. Os genes de resistência blaTEM, blaCTX-M, blaSHV e blaKPC foram identificados com oligonucleotídeos específicos e a tipagem genética foi realizada pela PCR com o microssatélite (GTG)5. Foram obtidos 254 isolados de enterobactérias, dos quais 92,12% (234/254) apresentaram alguns dos genes blaTEM, blaCTX-M, blaSHV ou blaKPC, sendo 87,18% (204/234) ESBL…

Advisors/Committee Members: Silva Filho, Eurípedes Alves da, CPF:16649630497, SILVA FILHO, E. A., Ferreira, Sonia Maria Soares, CPF:29912989449, http://lattes.cnpq.br/1584568707943074, Azevedo, Dalmo Almeida de, CPF:49935275949, http://lattes.cnpq.br/4202083703695616, Tovar, Francisco Javier, CPF:02177610702, http://lattes.cnpq.br/2366497420587582.

Streptococcus agalactiae est la première cause d’infections invasives chez le nouveau né et, malgré la mise en place de stratégies de prévention, cette bactérie reste le principal agent étiologique des infections néonatales. Les souches de séquence type 17, dites hyper-virulentes, sont particulièrement associées avec les méningites, type d’infection ayant des conséquences lourdes en terme de mortalité et morbidité. Ce clone possède des caractéristiques uniques, telle que la fixation au fibrinogène, ainsi qu’un répertoire de protéines de surface qui lui sont spécifiques. Parmi ces protéines, Srr2 appartient à une famille de larges glycoprotéines streptococcales et staphylococcales impliquées dans la pathogénicité. Un domaine central de Srr2, le domaine BR, est responsable de la fixation spécifique du fibrinogène par le clone ST-17, ainsi qu’au plasminogène et à divers composants de la matrice extracellulaire. Cette protéine promeut ainsi l’adhésion et le franchissement des barrières cellulaires. L’interaction de Srr2 avec les systèmes fibrinolytique et de coagulation de l’hôte favorise la dissémination bactérienne par l’activation de la fibrinolyse, et la persistance de la bactérie dans l’organisme par la formation d’agrégats bactériens. La liaison de Srr2 avec le fibrinogène semble également promouvoir la persistance bactérienne en favorisant l’internalisation et la survie dans les macrophages. Ainsi, la protéine Srr2 confère un avantage pour le processus infectieux du clone ST-17 dans l’hôte, et constitue une cible vaccinale intéressante pour la prévention des infections à S. agalactiae.

Streptococcus agalactiae is the leading cause of invasive infections in neonates. Despite the implementation of prevention strategies, this bacterium remains the main etiological agent of neonatal infections. Hyper-virulent sequence-type 17 strains are particularly associated with meningitis, a type of infection with serious consequences in terms of mortality and morbidity. This clone has unique characteristics, such as fibrinogen binding, and a panel of specific surface proteins. Among these proteins, Srr2 belongs to a family of large streptococcal and staphylococcal glycoproteins involved in pathogenicity. A central domain of Srr2, BR domain, is responsible for the specific binding of fibrinogen by the ST -17 clone and also binds plasminogen and various components of the extracellular matrix. Thereby, it promotes adhesion and crossing of cellular barriers. The interaction of Srr2 with fibrinolytic and coagulation systems of the host could promote bacterial spread through the activation of fibrinolysis and the persistence of the bacteria in the host by the formation of bacterial aggregates. The interaction of Srr2 with fibrinogen also seems to promote bacterial persistence in promoting the internalization and survival of the bacteria in macrophages. Thus, Srr2 confers an advantage to the infectious process of the ST- 17 clone in the host and is an attractive vaccine candidate for the prevention of S. agalactiae infections.

Advisors/Committee Members: Poyart, Claire (thesis director).