Avaliação da ocorrência de coliformes e resistência a antibióticos na bacia do Rio Infulene

Abstract

The Infulene River basin, located in urban areas between the municipalities of Maputo and Matola, receives along its course effluent discharges mainly from industries, the wastewater treatment plant, and agricultural activities, which directly affect water quality. Pollution poses an additional risk as it may promote antimicrobial resistance, which over the past decade has become a global public health emergency, since resistant microorganisms tend to persist in aquatic environments, making the treatment of infections more difficult for populations using the river water in their daily activities. This study assessed the occurrence of coliforms and antimicrobial resistance in the Infulene River basin. The methodology included spatio-temporal analysis of physicochemical and microbiological parameters at fourteen sampling points during three campaigns conducted in July, August, and October 2023, both in the field and in the laboratory. The parameters analyzed were: temperature, pH, electrical conductivity, dissolved oxygen, nitrates, phosphates, biochemical oxygen demand, total coliforms, Escherichia coli (E. coli), and extended-spectrum β-lactamase producing E. coli (ESBL E. coli). The results revealed concentrations above the limits established by national legislation (Decree No. 18/2004 of June 2 and Decree No. 52/2023 of August 30). Total coliforms and E. coli were detected in almost all sampling points, ranging from 3.4×10³ – 9.4×10⁷ MPN/100 mL and 100 – 9.6×10⁶ MPN/100 mL, respectively. ESBL E. coli counts reached a maximum of 5.9×10⁵ CFU/100 mL, confirming fecal contamination and the presence of antimicrobial resistance. These findings highlight the urgent need for intervention measures to improve water quality and basic sanitation, thus contributing to controlling the spread of pathogenic and antibiotic-resistant microorganisms.