Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFU |
Texto Completo: | https://repositorio.ufu.br/handle/123456789/18864 http://dx.doi.org/10.14393/ufu.te.2017.72 |
Resumo: | Klebsiella pneumoniae is often involved with healthcare-associated infections (HAI) in Brazil, and has a great ability to develop or acquire antimicrobial resistance. This study investigated the clonal dissemination and prevalence of sequence types (STs) in clinical strains of K. pneumoniae carrying blaCTX-M e blaKPC genes, as well as the presence of genes encoding virulence factors and the ability of these strains to produce biofilms. In addition, the impact of carbapenem and polymyxin-resistance on bacterial fitness of carbapenemase-producing K. pneumoniae (KPC) strains was also examined. We randomly selected non-duplicated K. pneumoniae isolates from a collection recovered from inpatients at the Clinical Hospital of the Federal University of Uberlândia (HC-UFU) from June 2009 to July 2015. The study included broad-spectrum cephalosporin and/or carbapenems-resistant strains. For investigation of the blaCTX-M and blaKPC resistance genes and its association with virulence genes (fimH, fimA, wabG, iucC, rmpA, ecpA, mrkD e khe), the strains were evaluated by PCR. DNA sequencing was performed to confirm the presence of blaKPC-2 gene. The pulsotypes, STs and clonal complexes (CCs) were determined by PFGE and MLST, respectively. Initial adhesion and biofilm formation were examined by quantitative assays and the results confirmed by scanning electron microscopy. For fitness evaluation, in vitro pairwise competition experiments were carried out using three strains of K. pneumoniae: one resistant to carbapenem, harboring 5 of the 8 evaluated virulence genes, another less virulent, but resistant to carbapenem and polymyxin, and ATCC 10031 multisensitive strain. For epidemiological evaluations, sixty K. pneumoniae strains were randomly selected, of which 30 carbapenem-sensitive (KpSC) strains isolated from infections; 30 carbapenem-resistant K. pneumoniae (KpRC) strains, 20 isolated from infections and 10 from colonizations. Significant differences were found when patients infected by KpSC and KpRC were compared, especially the high previous use of β-lactams (53%), carbapenems (73.3%) and polymyxin B (43.3%). Inadequate therapy, although prevalent in 56.7% of the patients, was much higher (70%) among those with KpRC infections. In total, 75% of the strains were characterized as multiresistant. Furthermore, we observed high consumption of cefepime, ceftriaxone and carbapenems by defined daily doses analysis, with an upward trend between the beginning and the end of the period of study. Regarding the presence of resistance genes, 80% of strains carried blaCTX-M gene and 100% of carbapenem-resistant isolates the blaKPC-2 gene. Virulence genes were detected with high frequencies in both groups, unrelated to carbapenem resistance. However, among the KpRC strains, the fimH, fimA and wabG genes were predominant (83%). It was observed polyclonal dissemination of strains with predominance of MLST STs 11 and 340, belonging to the clonal complex 258. All K. pneumoniae strains evaluated could adhere to an unmodified polystyrene surface. However, the statistical analysis showed that three strains had remarkably higher adhesion rates than the others (p<0.001). Compared to control, all strains had the ability to produce biofilm, without significant differences. However, the evaluation of biomass by crystal violet showed that 60% of the isolates were weak biofilm producers, results confirmed by scanning electron microscopy. According to the fitness results, the polymyxin-resistant strain was found to have more significant growth rates (p=0.030) and, in competition experiments between the two multiresistant clinical strains, the carbapenem-resistant strain showed a significantly lower fitness cost when compared to the carbapenem and polymyxin-resistant strain. The knowledge of the virulence factors and the pathogenic potential of ESBL and carbapenemases-producing K. pneumoniae contributes to a better understanding of colonization, pathogenicity and persistence of these microorganisms in the hospital environment and can provide tools to improve the treatment of serious infections as well as subsidies to improve infection control and prevention measures. |
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Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPCImunologiaBiofilmeInfecção hospitalarPoliclonalidadeMultirresistênciaCarbapenêmicosVirulênciaBiofilmes bacterianosAptidão biológicaPolyclonalityMultiresistanceCarbapenemsVirulenceBacterial biofilmsFitnessCNPQ::CIENCIAS BIOLOGICAS::IMUNOLOGIAKlebsiella pneumoniae is often involved with healthcare-associated infections (HAI) in Brazil, and has a great ability to develop or acquire antimicrobial resistance. This study investigated the clonal dissemination and prevalence of sequence types (STs) in clinical strains of K. pneumoniae carrying blaCTX-M e blaKPC genes, as well as the presence of genes encoding virulence factors and the ability of these strains to produce biofilms. In addition, the impact of carbapenem and polymyxin-resistance on bacterial fitness of carbapenemase-producing K. pneumoniae (KPC) strains was also examined. We randomly selected non-duplicated K. pneumoniae isolates from a collection recovered from inpatients at the Clinical Hospital of the Federal University of Uberlândia (HC-UFU) from June 2009 to July 2015. The study included broad-spectrum cephalosporin and/or carbapenems-resistant strains. For investigation of the blaCTX-M and blaKPC resistance genes and its association with virulence genes (fimH, fimA, wabG, iucC, rmpA, ecpA, mrkD e khe), the strains were evaluated by PCR. DNA sequencing was performed to confirm the presence of blaKPC-2 gene. The pulsotypes, STs and clonal complexes (CCs) were determined by PFGE and MLST, respectively. Initial adhesion and biofilm formation were examined by quantitative assays and the results confirmed by scanning electron microscopy. For fitness evaluation, in vitro pairwise competition experiments were carried out using three strains of K. pneumoniae: one resistant to carbapenem, harboring 5 of the 8 evaluated virulence genes, another less virulent, but resistant to carbapenem and polymyxin, and ATCC 10031 multisensitive strain. For epidemiological evaluations, sixty K. pneumoniae strains were randomly selected, of which 30 carbapenem-sensitive (KpSC) strains isolated from infections; 30 carbapenem-resistant K. pneumoniae (KpRC) strains, 20 isolated from infections and 10 from colonizations. Significant differences were found when patients infected by KpSC and KpRC were compared, especially the high previous use of β-lactams (53%), carbapenems (73.3%) and polymyxin B (43.3%). Inadequate therapy, although prevalent in 56.7% of the patients, was much higher (70%) among those with KpRC infections. In total, 75% of the strains were characterized as multiresistant. Furthermore, we observed high consumption of cefepime, ceftriaxone and carbapenems by defined daily doses analysis, with an upward trend between the beginning and the end of the period of study. Regarding the presence of resistance genes, 80% of strains carried blaCTX-M gene and 100% of carbapenem-resistant isolates the blaKPC-2 gene. Virulence genes were detected with high frequencies in both groups, unrelated to carbapenem resistance. However, among the KpRC strains, the fimH, fimA and wabG genes were predominant (83%). It was observed polyclonal dissemination of strains with predominance of MLST STs 11 and 340, belonging to the clonal complex 258. All K. pneumoniae strains evaluated could adhere to an unmodified polystyrene surface. However, the statistical analysis showed that three strains had remarkably higher adhesion rates than the others (p<0.001). Compared to control, all strains had the ability to produce biofilm, without significant differences. However, the evaluation of biomass by crystal violet showed that 60% of the isolates were weak biofilm producers, results confirmed by scanning electron microscopy. According to the fitness results, the polymyxin-resistant strain was found to have more significant growth rates (p=0.030) and, in competition experiments between the two multiresistant clinical strains, the carbapenem-resistant strain showed a significantly lower fitness cost when compared to the carbapenem and polymyxin-resistant strain. The knowledge of the virulence factors and the pathogenic potential of ESBL and carbapenemases-producing K. pneumoniae contributes to a better understanding of colonization, pathogenicity and persistence of these microorganisms in the hospital environment and can provide tools to improve the treatment of serious infections as well as subsidies to improve infection control and prevention measures.FAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas GeraisTese (Doutorado)Klebsiella pneumoniae é um agente etiológico frequente em infecções relacionadas à assistência à saúde no Brasil e possui uma grande capacidade de desenvolver ou adquirir resistência aos antimicrobianos. Este estudo investigou a disseminação clonal e os tipos de sequência (STs) predominantes em amostras clínicas de K. pneumoniae apresentando genes blaCTX-M e blaKPC, bem como a presença de genes para fatores de virulência e a capacidade de produção de biofilmes. Adicionalmente, também foi examinado o impacto das resistências aos carbapenêmicos e polimixina no fitness bacteriano de K. pneumoniae produtoras de carbapenemase (KPC). Para as avaliações epidemiológicas foram selecionadas randomicamente 60 amostras não-duplicadas de K. pneumoniae, sendo 30 amostras de infecção K. pneumoniae sensível aos carbapenêmicos (KpSC), 20 infecções e 10 colonizações por K. pneumoniae resistente aos carbapenêmicos (KpRC). As amostras foram selecionadas a partir de uma coleção recuperada de pacientes internados no Hospital de Clínicas da Universidade Federal de Uberlândia (HC-UFU) no período de junho de 2009 a julho de 2015. Para investigação dos genes de resistência blaCTX-M e blaKPC e genes de virulência fimH, fimA, wabG, iucC, rmpA, ecpA, mrkD e khe, as amostras foram avaliadas por reação em cadeia da polimerase (PCR). A confirmação de blaKPC-2 foi realizada por sequenciamento genético. Os pulsotipos, STs e complexos clonais foram determinados por Pulsed Field Gel Electrophoresis (PFGE) e Multilocus Sequence Typing (MLST). A adesão inicial e a formação de biofilme foram examinadas por ensaios quantitativos, e os resultados confirmados por microscopia eletrônica de varredura. Para avaliação do fitness foram utilizados experimentos de competição em pares, in vitro, utilizando três amostras de K. pneumoniae: uma resistente aos carbapenêmicos, contendo 5 dos 8 genes de virulência avaliados, uma resistente aos carbapenêmicos e polimixina, menos virulenta, e a amostra ATCC 10031 multissensível. Diferenças importantes foram encontradas na caracterização dos grupos KpSC e KpRC, destacando-se o elevado uso prévio de β-lactâmicos (53%), carbapenêmicos (73,3%) e polimixina B (43,3%) naqueles infectados por amostras resistentes. A terapia inadequada embora tenha sido prevalente em 56,7% dos casos, foi bem maior (70%) entre pacientes com infecções por KpRC. No total, 75% das amostras foram caracterizadas como multirresistentes. Além disso, foi observado alto consumo em DDD de cefepime, ceftriaxona e carbapenêmicos, com tendência ascendente entre o início e o final do período estudado. Em relação à presença de genes de resistência, 80% das amostras apresentaram o gene blaCTX-M e 100% das amostras com resistência aos carbapenêmicos possuíam o gene blaKPC. Os genes de virulência foram detectados com frequências elevadas em ambos os grupos, sem relação com a resistência aos carbapenêmicos. Entretanto, entre as amostras de KpRC, os genes fimH, fimA e wabG foram predominantes (83%). Observou-se disseminação policlonal das amostras com predominância dos STs 11 e 340, pertencentes ao complexo clonal 258. Todas as amostras de K. pneumoniae avaliadas foram capazes de aderir a uma superfície de poliestireno não modificada. No entanto, a análise estatística evidenciou que três amostras apresentaram taxas de adesão notavelmente mais altas do que as demais (p<0.001). Comparados ao controle, todas as amostras apresentaram a habilidade de produzir biofilme, sem diferenças significativas. No entanto, a avaliação da biomassa por cristal violeta evidenciou que 60% das amostras eram produtoras fracas de biofilme, resultado confirmado pela microscopia eletrônica de varredura. De acordo com os resultados do fitness, observou-se que a amostra resistente à polimixina apresentou taxas de crescimento mais significativas (p=0,030) e na competição entre as duas amostras clínicas multirresistentes, a amostra resistente ao carbapenêmico mostrou custo de fitness significativamente menor quando comparado à amostra resistente aos carbapenêmicos e à polimixina. O conhecimento dos fatores de virulência e o potencial patogênico de K. pneumoniae produtoras de ESBL e carbapenemases contribui para melhor compreensão da colonização, patogenicidade e persistência desses micro-organismos no ambiente hospitalar e pode fornecer ferramentas para melhorar o tratamento de infecções graves, assim como subsídios para aprimorar as medidas de controle e prevenção de infecções.Universidade Federal de UberlândiaBrasilPrograma de Pós-graduação em Imunologia e Parasitologia AplicadasRibas, Rosineide Marqueshttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4773602H1Rocha, Lilian Alveshttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4719569E7Dantas, Raquel Cristina Cavalcantihttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4201027A6Cezario, Renata Cristinahttp://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4779849E4Campos, Paola Amaral de2017-06-13T13:06:50Z2017-06-13T13:06:50Z2017-03-13info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisapplication/pdfCAMPOS, Paola Amaral de. Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC. 2017. 97 f. Tese (Doutorado em Imunologia e Parasitologia Aplicadas) - Universidade Federal de Uberlândia, Uberlândia, 2017. DOI http://dx.doi.org/10.14393/ufu.te.2017.72https://repositorio.ufu.br/handle/123456789/18864http://dx.doi.org/10.14393/ufu.te.2017.72porinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFUinstname:Universidade Federal de Uberlândia (UFU)instacron:UFU2019-06-07T15:07:49Zoai:repositorio.ufu.br:123456789/18864Repositório InstitucionalONGhttp://repositorio.ufu.br/oai/requestdiinf@dirbi.ufu.bropendoar:2019-06-07T15:07:49Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU)false |
dc.title.none.fl_str_mv |
Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC |
title |
Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC |
spellingShingle |
Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC Campos, Paola Amaral de Imunologia Biofilme Infecção hospitalar Policlonalidade Multirresistência Carbapenêmicos Virulência Biofilmes bacterianos Aptidão biológica Polyclonality Multiresistance Carbapenems Virulence Bacterial biofilms Fitness CNPQ::CIENCIAS BIOLOGICAS::IMUNOLOGIA |
title_short |
Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC |
title_full |
Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC |
title_fullStr |
Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC |
title_full_unstemmed |
Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC |
title_sort |
Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC |
author |
Campos, Paola Amaral de |
author_facet |
Campos, Paola Amaral de |
author_role |
author |
dc.contributor.none.fl_str_mv |
Ribas, Rosineide Marques http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4773602H1 Rocha, Lilian Alves http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4719569E7 Dantas, Raquel Cristina Cavalcanti http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4201027A6 Cezario, Renata Cristina http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4779849E4 |
dc.contributor.author.fl_str_mv |
Campos, Paola Amaral de |
dc.subject.por.fl_str_mv |
Imunologia Biofilme Infecção hospitalar Policlonalidade Multirresistência Carbapenêmicos Virulência Biofilmes bacterianos Aptidão biológica Polyclonality Multiresistance Carbapenems Virulence Bacterial biofilms Fitness CNPQ::CIENCIAS BIOLOGICAS::IMUNOLOGIA |
topic |
Imunologia Biofilme Infecção hospitalar Policlonalidade Multirresistência Carbapenêmicos Virulência Biofilmes bacterianos Aptidão biológica Polyclonality Multiresistance Carbapenems Virulence Bacterial biofilms Fitness CNPQ::CIENCIAS BIOLOGICAS::IMUNOLOGIA |
description |
Klebsiella pneumoniae is often involved with healthcare-associated infections (HAI) in Brazil, and has a great ability to develop or acquire antimicrobial resistance. This study investigated the clonal dissemination and prevalence of sequence types (STs) in clinical strains of K. pneumoniae carrying blaCTX-M e blaKPC genes, as well as the presence of genes encoding virulence factors and the ability of these strains to produce biofilms. In addition, the impact of carbapenem and polymyxin-resistance on bacterial fitness of carbapenemase-producing K. pneumoniae (KPC) strains was also examined. We randomly selected non-duplicated K. pneumoniae isolates from a collection recovered from inpatients at the Clinical Hospital of the Federal University of Uberlândia (HC-UFU) from June 2009 to July 2015. The study included broad-spectrum cephalosporin and/or carbapenems-resistant strains. For investigation of the blaCTX-M and blaKPC resistance genes and its association with virulence genes (fimH, fimA, wabG, iucC, rmpA, ecpA, mrkD e khe), the strains were evaluated by PCR. DNA sequencing was performed to confirm the presence of blaKPC-2 gene. The pulsotypes, STs and clonal complexes (CCs) were determined by PFGE and MLST, respectively. Initial adhesion and biofilm formation were examined by quantitative assays and the results confirmed by scanning electron microscopy. For fitness evaluation, in vitro pairwise competition experiments were carried out using three strains of K. pneumoniae: one resistant to carbapenem, harboring 5 of the 8 evaluated virulence genes, another less virulent, but resistant to carbapenem and polymyxin, and ATCC 10031 multisensitive strain. For epidemiological evaluations, sixty K. pneumoniae strains were randomly selected, of which 30 carbapenem-sensitive (KpSC) strains isolated from infections; 30 carbapenem-resistant K. pneumoniae (KpRC) strains, 20 isolated from infections and 10 from colonizations. Significant differences were found when patients infected by KpSC and KpRC were compared, especially the high previous use of β-lactams (53%), carbapenems (73.3%) and polymyxin B (43.3%). Inadequate therapy, although prevalent in 56.7% of the patients, was much higher (70%) among those with KpRC infections. In total, 75% of the strains were characterized as multiresistant. Furthermore, we observed high consumption of cefepime, ceftriaxone and carbapenems by defined daily doses analysis, with an upward trend between the beginning and the end of the period of study. Regarding the presence of resistance genes, 80% of strains carried blaCTX-M gene and 100% of carbapenem-resistant isolates the blaKPC-2 gene. Virulence genes were detected with high frequencies in both groups, unrelated to carbapenem resistance. However, among the KpRC strains, the fimH, fimA and wabG genes were predominant (83%). It was observed polyclonal dissemination of strains with predominance of MLST STs 11 and 340, belonging to the clonal complex 258. All K. pneumoniae strains evaluated could adhere to an unmodified polystyrene surface. However, the statistical analysis showed that three strains had remarkably higher adhesion rates than the others (p<0.001). Compared to control, all strains had the ability to produce biofilm, without significant differences. However, the evaluation of biomass by crystal violet showed that 60% of the isolates were weak biofilm producers, results confirmed by scanning electron microscopy. According to the fitness results, the polymyxin-resistant strain was found to have more significant growth rates (p=0.030) and, in competition experiments between the two multiresistant clinical strains, the carbapenem-resistant strain showed a significantly lower fitness cost when compared to the carbapenem and polymyxin-resistant strain. The knowledge of the virulence factors and the pathogenic potential of ESBL and carbapenemases-producing K. pneumoniae contributes to a better understanding of colonization, pathogenicity and persistence of these microorganisms in the hospital environment and can provide tools to improve the treatment of serious infections as well as subsidies to improve infection control and prevention measures. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-06-13T13:06:50Z 2017-06-13T13:06:50Z 2017-03-13 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
CAMPOS, Paola Amaral de. Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC. 2017. 97 f. Tese (Doutorado em Imunologia e Parasitologia Aplicadas) - Universidade Federal de Uberlândia, Uberlândia, 2017. DOI http://dx.doi.org/10.14393/ufu.te.2017.72 https://repositorio.ufu.br/handle/123456789/18864 http://dx.doi.org/10.14393/ufu.te.2017.72 |
identifier_str_mv |
CAMPOS, Paola Amaral de. Disseminação de Klebsiella pneumoniae multirresistente: produção de biofilme, avaliação da virulência e do fitness bacteriano em amostras clínicas produtoras de KPC. 2017. 97 f. Tese (Doutorado em Imunologia e Parasitologia Aplicadas) - Universidade Federal de Uberlândia, Uberlândia, 2017. DOI http://dx.doi.org/10.14393/ufu.te.2017.72 |
url |
https://repositorio.ufu.br/handle/123456789/18864 http://dx.doi.org/10.14393/ufu.te.2017.72 |
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por |
language |
por |
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info:eu-repo/semantics/openAccess |
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openAccess |
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dc.publisher.none.fl_str_mv |
Universidade Federal de Uberlândia Brasil Programa de Pós-graduação em Imunologia e Parasitologia Aplicadas |
publisher.none.fl_str_mv |
Universidade Federal de Uberlândia Brasil Programa de Pós-graduação em Imunologia e Parasitologia Aplicadas |
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reponame:Repositório Institucional da UFU instname:Universidade Federal de Uberlândia (UFU) instacron:UFU |
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Universidade Federal de Uberlândia (UFU) |
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UFU |
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Repositório Institucional da UFU |
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Repositório Institucional da UFU - Universidade Federal de Uberlândia (UFU) |
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diinf@dirbi.ufu.br |
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