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Previous issue date: 2012-03-30 / Stenotrophomonas maltophilia is an important opportunistic and emerging pathogen commonly related to nosocomial infections and found in different environmental sources, including hospital settings. This microorganism is recognized for presenting intrinsic resistance to a range of important antimicrobials as well as to acquire resistance by horizontal gene transfer, which reduces the effective options for the treatment of infections caused by this organism. Therefore, the aim of this study was to determine the presence of S. maltophilia in the nosocomial environment and characterize the resistance of the environmental isolates, as well as clinical isolates obtained in the same hospital. Then, environmental samples were collected in the general ICU and the Unified Health System hospitalization unit of the S?o Lucas Hospital, Porto Alegre, Brazil. In addition, 100 clinical isolates were sent by the Clinical Pathology Laboratory of the same hospital. All samples were analyzed using a specific protocol for S. maltophilia detection by PCR developed in this study targeting 23S rRNA gene. Subsequently, the antimicrobial resistance was evaluated against ceftazidime, chloramphenicol, levofloxacin, minociclin and trimethoprim/sulfamethoxazole (TMP/SMX). The presence of integrons was verified in all isolates and those that presented reduced susceptibility to TMP/SMX was evaluated the presence of sul1 and sul2 gene, as well as was determined the plasmid profile. All isolates were submitted to detection of smf-1 gene. Among the 936 samples collected in the nosocomial environment, S. maltophilia was identified in 28. High rates of susceptibility to minocycline, levofloxacin and chloramphenicol were observed, and all of the 19 isolates that presented reduced susceptibility to TMP/SMX carried the sul1 gene, 14 of them presented class 1 integron and nine isolates showed simultaneously sul1 and sul2. All isolates that carried the sul2 gene also presented the 7.3 kb plasmid. The smf-1 gene was detected in 31 S. maltophilia isolates. The presence of S. maltophilia in hospital environment and medical devices indicates the permanence of this microorganism in the nosocomial environment, what can constitute a risk to infection for other hospitalized patients. In addition, the data obtained in this study in relation to TMP/SMX susceptibility can suggest that the resistance to these drugs have the tendency to increase, especially due to resistance determinants to these drugs can be associated to mobile genetic elements, which may facilitate horizontal transfer and the spread of these resistance genes. / Stenotrophomonas maltophilia ? um importante pat?geno oportunista e emergente, comumente relacionado a infec??es nosocomiais e encontrado em diferentes locais, incluindo o ambiente hospitalar. Este microrganismo ? reconhecido por apresentar resist?ncia intr?nseca a uma gama importante de antimicrobianos, bem como por adquirir resist?ncia atrav?s de transfer?ncia g?nica horizontal, o que reduz as op??es efetivas para o tratamento de infec??es ocasionadas por este microrganismo. Desta forma, o objetivo deste estudo foi determinar a presen?a de S. maltophilia no ambiente hospitalar e caracterizar a resist?ncia a drogas antimicrobianas dos isolados ambientais, bem como dos isolados cl?nicos obtidos no mesmo hospital. Para tanto, amostras ambientais foram coletadas na UTI Geral e no andar referente ? interna??o pelo Sistema ?nico de Sa?de (SUS) do Hospital S?o Lucas, Porto Alegre, Brasil. Al?m disso, 100 isolados cl?nicos foram cedidos pelo Laborat?rio de Patologia Cl?nica do mesmo hospital. Todas as amostras foram analisadas utilizando um protocolo de detec??o espec?fica de S. maltophilia atrav?s de PCR desenvolvido neste estudo, tendo o gene RNAr 23S como alvo. Posteriormente, foi avaliada a resist?ncia dos isolados frente ? ceftazidima, cloranfenicol, levofloxacina, minociclina e trimetoprim/sulfametoxazol (TMP/SMX). A presen?a de integrons foi verificada em todos os isolados e naqueles com suscetibilidade reduzida a TMP/SMX foi avaliada a presen?a dos genes sul1 e sul2, bem como foi determinado o perfil plasmidial. Todos os isolados foram submetidos ? detec??o do gene smf-1. De um total de 936 amostras coletadas no ambiente hospitalar, S. maltophilia foi identificada em 28. Foram observadas elevadas taxas de suscetibilidade ? minociclina, levofloxacina e cloranfenicol e todos os 19 isolados que apresentaram suscetibilidade reduzida ? combina??o TMP/SMX carrearam o gene sul1, 14 destes apresentaram o integron de classe 1 e nove isolados apresentaram concomitantemente os genes sul1 e sul2. Todos os isolados que carrearam o gene sul2 apresentaram o plasm?deo de 7,3 kb. O gene smf-1 foi detectado em 31 isolados de S. maltophilia. A presen?a de S. maltophilia nos materiais e equipamentos hospitalares indica a perman?ncia destas bact?rias no ambiente hospitalar, podendo constituir risco para infec??o de outros pacientes internados. Al?m disso, os dados obtidos neste estudo em rela??o ? suscetibilidade ? TMP/SMX podem sugerir que a resist?ncia a esta combina??o de drogas possa estar em ascens?o, especialmente porque os determinantes de resist?ncia a estas drogas podem estar associados a elementos gen?ticos m?veis, o que facilitaria a transfer?ncia horizontal e a dissemina??o destes genes de resist?ncia.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/5441 |
| Date | 30 March 2012 |
| Creators | Gallo, Stephanie Wagner |
| Contributors | Oliveira, Silvia Dias de |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Biologia Celular e Molecular, PUCRS, BR, Faculdade de Bioci?ncias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | Spanish |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 8198246930096637360, 600, 600, 36528317262667714 |
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