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Abstract(s)
A ĂĄgua Ă© um recurso escasso e indispensĂĄvel Ă vida, podendo ser um importante veĂculo de microrganismos patogĂ©nicos com origem fecal. A matĂ©ria fecal Ă© tambĂ©m uma fonte de microrganismos resistentes a antimicrobianos e contribui para a sua disseminação e dos seus genes de resistĂȘncia no ambiente e entre as comunidades microbianas comensais e microrganismos patogĂ©nicos humanos e animais. A qualidade microbiolĂłgica da ĂĄgua Ă© monitorizada recorrendo Ă utilização de bioindicadores como Escherichia coli, enterococos e microrganismos totais.
O presente estudo apresentou como principal objetivo determinar a prevalĂȘncia de ESBLs e AmpCs e ainda avaliar a prevalĂȘncia de estirpes de enterococos com resistĂȘncia Ă vancomicina (VRE) em ĂĄguas do rio Douro e da orla costeira da cidade do Porto.
As amostragens de ĂĄgua foram realizadas em quatro locais localizados no estuĂĄrio do rio Douro e orla costeira da cidade do Porto entre o mĂȘs de Abril e Julho. A deteção e quantificação dos bioindicadores foram realizadas pelo mĂ©todo de filtração por membrana. A suscetibilidade das estirpes de E. coli e enterococos foi testada pelo mĂ©todo de difusĂŁo em disco relativamente a vĂĄrias classes de antimicrobianos.
As contagens microbianas mais elevadas foram determinadas entre Abril e Junho e em amostras de ĂĄgua doce. Foram isoladas 62 estirpes de E. coli e 49 estirpes de enterococos que apresentaram prevalĂȘncias de resistĂȘncia a antimicrobianos de 90,3% (56/62) e 83,7% (41/49), respetivamente. As estirpes de E. coli apresentaram altas frequĂȘncias de resistĂȘncia Ă ampicilina (74,2%) e tetraciclina (61,3%). Nestas estirpes verificou-se ainda fenĂłtipos associados a multirresistĂȘncia a um mĂnimo de trĂȘs classes de antimicrobianos em 56,5% (35/62) dos isolados. Verificou-se que as estirpes de enterococos apresentaram altos nĂveis de resistĂȘncia Ă rifampicina (34,7%) e azitromicina (40,8%), detetando-se ainda a manifestação de fenĂłtipo de resistĂȘncia Ă vancomicina em 26,5% das estirpes. Observou-se uma prevalĂȘncia de 36,7% (18/49) de estirpes de enterococos associadas a fenĂłmenos de multirresistĂȘncia antimicrobiana.
Ana Martins
vi
Os resultados obtidos sugerem que o rio Douro e orla costeira, bem como os ambientes aquĂĄticos, constituem reservatĂłrios de bactĂ©rias e genes de resistĂȘncia a antimicrobianos e possuem um papel preponderante na sua disseminação.
Water is a scarce resource and essential to life that can be an important vehicle of pathogenic enteric bacteria. Fecal matter is also a source of antimicrobial resistant bacteria and contributes to its spread and their resistance genes into the environment and among commensal communities and human and animal pathogenic bacteria. The microbiological quality of water is monitored by the use of fecal indicator bacteria such as Escherichia coli, enterococci and total microorganisms. The main objective of this study has to determine the prevalence of ESBLs and AmpC in environmental isolates of E. coli and also evaluate the prevalence of vancomycin-resistant enterococci strains (VRE).from Douro river estuary and coastline of Oporto city. In the present study water samples were collected at four sites located in the Douro river estuary and coastline between April and July. The detection and quantification of biomarkers was performed by the filter membrane method. The susceptibility of strains of E. coli and enterococci was tested by the disk diffusion method to various classes of antimicrobials. The higher microbial counts were determined between April and June in freshwater samples. There were isolated 62 E. coli strains and 49 enterococci strains that showed 90,3% (56/62) and 83,7% (41/49) antimicrobial resistance, respectively. E.coli strains showed higher frequencies of resistance to ampicillin (74,2%) and tetracycline (61,3%). In these strains it was found phenotypes associated with multiple antimicrobial resistance to at least three classes of antimicrobial agents in 56,5% (35/62) of the isolates. It has been found that enterococci strains showed high resistance levels to rifampicin (34,0%) and azithromycin (40,8%), and was detected the expression of vancomycin resistance phenotype in 26,5% of the strains. We found a prevalence of 36,7% (18/49) of enterococci strains associated with multidrug resistance phenomens. The results suggest that the Douro river and aquatic environments, constitute reservoirs of resistant bacteria and genes and have a leading role in their dissemination.
Water is a scarce resource and essential to life that can be an important vehicle of pathogenic enteric bacteria. Fecal matter is also a source of antimicrobial resistant bacteria and contributes to its spread and their resistance genes into the environment and among commensal communities and human and animal pathogenic bacteria. The microbiological quality of water is monitored by the use of fecal indicator bacteria such as Escherichia coli, enterococci and total microorganisms. The main objective of this study has to determine the prevalence of ESBLs and AmpC in environmental isolates of E. coli and also evaluate the prevalence of vancomycin-resistant enterococci strains (VRE).from Douro river estuary and coastline of Oporto city. In the present study water samples were collected at four sites located in the Douro river estuary and coastline between April and July. The detection and quantification of biomarkers was performed by the filter membrane method. The susceptibility of strains of E. coli and enterococci was tested by the disk diffusion method to various classes of antimicrobials. The higher microbial counts were determined between April and June in freshwater samples. There were isolated 62 E. coli strains and 49 enterococci strains that showed 90,3% (56/62) and 83,7% (41/49) antimicrobial resistance, respectively. E.coli strains showed higher frequencies of resistance to ampicillin (74,2%) and tetracycline (61,3%). In these strains it was found phenotypes associated with multiple antimicrobial resistance to at least three classes of antimicrobial agents in 56,5% (35/62) of the isolates. It has been found that enterococci strains showed high resistance levels to rifampicin (34,0%) and azithromycin (40,8%), and was detected the expression of vancomycin resistance phenotype in 26,5% of the strains. We found a prevalence of 36,7% (18/49) of enterococci strains associated with multidrug resistance phenomens. The results suggest that the Douro river and aquatic environments, constitute reservoirs of resistant bacteria and genes and have a leading role in their dissemination.
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Keywords
Bioindicadores contaminação fecal ResistĂȘncia antimicrobiana Ambiente Beta-lactamases espectro alargado Enterococos resistentes Ă vancomicina Fecal indicator bacteria Antimicrobial resistance Environment Extended spectrum beta-lactamases Vancomycin-resistant enterococci
Citation
Publisher
Instituto PolitĂ©cnico do Porto. Escola Superior de Tecnologia da SaĂșde do Porto