Dinâmica sazonal da contaminação microbiana da água do Parque Ecológico do Tietê
Data
2021
Autores
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Editor
Universidade Brasil
Resumo
The quality of water resources can be altered by human activities carried out in
watersheds. These changes can lead to the occurrence of antibiotic-resistant
bacteria and compromise public health. The aim of the present study was to evaluate
the presence and concentration of total coliforms and Escherichia coli in the water at
the Parque Ecológico do Tietê (Ecological Park Tietê) in São Paulo, the antibiotics
resistance of isolated E. coli and the correlation between physical-chemical
environmental and microbiological variables of the water. Sample localities were
georeferenced and identified as P1 - Drinking water from the distribution system; P2 -
Main lagoon of the park; and P3- Connection between the main lagoon and the Tietê
River. Physical-chemical and microbiological variables were measured, thus Principal
Component Analysis (PCA) and linear regression models were performed to verify
the correlation between these variables. The microbiological analysis was performed
by inoculating the samples in 3MTMPetrifilmTM plates, incubated at 37 ° C for 48 hours
and the E. coli isolated had their antibiotic resistance profile tested by the disk
diffusion technique using Mueller Hinton agar. Total coliforms and E. coli were not
identified at P1. Total coliforms were identified in 64% of the samples and E. coli was
identified in 36% of the samples. Water temperature and precipitation were the most
significant correlated variables and the linear regression models showed the
influence of seasonality on the concentration of E. coli in the water, with the highest
values in the rainy and warmer seasons. The isolated E. coli showed greater
resistance to erythromycin (82%) and amoxicillin (55%) in P2, and to erythromycin
(82%) and amoxicillin (27%) in P3, with the presence of multiresistant isolates at both
points. No strain showed resistance to amikacin. The high rate of resistance of E. coli
to the antibiotics frequently used in human and veterinary medicine demonstrates
that the contribution of these substances in aquatic ecosystems over the years has
exerted a selection pressure on microorganisms, assisting the appearance and
spread of resistant bacteria, changing the environmental biota and turning these
locations in possible reservoirs of antibiotic resistance.
Descrição
Palavras-chave
Bactérias, Coliformes, Escherichia coli, Recursos Hídricos