Diversidade e perfil de resistência de bactérias oriundas de bacia e microbacia urbana de Santarém, Pará, Brasil

Abstract

Basins and microbasins are depositaries of processes resulting from anthropogenic activities developed, causing a strong impact on environmental health and microbiota. Antibiotic resistance studies analyzing environmental microbiota, from matrices such as: water, soil and air, can be viable alternatives to understand the resistance acquisition cycle by human pathogens and opportunists, and which environmental factors can act in this selection. Thus, the present study aimed to study the diversity and evaluate the antimicrobial resistance profile of heterotrophic bacteria from the urban basin and microbasin in the municipality of Santarém, in the state of Pará. The collections were carried out in the morning, in at least two different points of the Tapajós river basin and microbasin in urban and peri-urban areas, during the rainy and dry periods. After collection, the water samples were placed in sterile glass bottles and kept under refrigeration until they arrived at the laboratory for microbiological analysis. After cultivation in Plate Count Agar (PCA) medium and isolation of bacteria in Tryptona Soja Agar (TSA), morphotinctorial and biochemical tests were performed and the profile of resistance to antimicrobials was carried out using the disk diffusion technique in Mueller Hinton medium, through of the Kirby Bauer method. Eight antimicrobials of seven classes were tested: fluoroquinolones - ciprofloxacin (5 μg); carbapenems - imipenem (10 μg); nitrofurantoin (300 μg); chloramphenicol (30 μg); penicillins - penicillin (10 I.U); oxacillin (1 μg); aminopenicillins - ampicillin (10 μg); beta-lactams - amoxicillin/clavulanic acid (20/10μg); macrolides - erythromycin (15 μg) and aminoglycosides - gentamicin (30 μg); amikacin (30 μg). The results showed the presence of the genera Corynebacterium sp., Clostridium sp., Lactobacillus sp., Staphylococcus sp., Staphylococcus aureus, Serratia sp., Shigella sp. and Yersinia sp. The bacterial strains tested were resistant to several antimicrobial drugs, of which 78.2% showed resistance to at least one antibiotic. In the present study, the samples were obtained from natural sources close to urban and peri-urban areas, which makes them even easier environments for primary contact.