Diving into the unknown: identification of antimicrobial resistance hotspots in a tropical urban estuary

• Published in: Letters in applied microbiology Vol. 73; no. 3; pp. 270 - 279
• Main Authors: Canellas, A.L.B., Costa, W.F., Paranhos, R., Laport, M.S.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.09.2021
• Subjects: Aeromonas; Amides; Antimicrobial agents; Antimicrobial resistance; Aquatic environment; Aquatic habitats; Bacteria; Drug resistance; Estuaries; Guanabara Bay; Mass spectrometry; Mass spectroscopy; Public health; Recreation areas; sewage pollution; Tourist attractions; Vibrio; Water analysis; Water sampling
• ISSN: 0266-8254; 1472-765X
• DOI: 10.1111/lam.13524

Antimicrobial resistance is widely studied and well‐characterized from a clinical perspective. However, considerably less information is available regarding resistance in environmental settings, especially in aquatic habitats. This study presents data regarding the occurrence, distribution and the antimicrobial susceptibility profile of bacteria isolated from Guanabara Bay (GB), a heavily polluted tropical urban estuary and an important tourist attraction in Rio de Janeiro, Brazil. Water samples from sites characterized by growing degrees of pollution were analysed by culture‐dependent methods, revealing the presence of multidrug‐resistant bacteria and clinically relevant indicators of antimicrobial resistance, such as extended‐spectrum beta‐lactamases. Isolates were identified by mass spectrometry, which indicated the presence of potential human pathogens such as Aeromonas spp. and Vibrio spp. Bacteria harbouring beta‐lactam resistance genes were also detected. Although GB is widely used as a recreational and fishing area, there is a substantial knowledge gap regarding the monitoring of antimicrobial resistance and the risk that exposure to these waters poses to public health. Thus, this study reveals new information that calls for better comprehension of antimicrobial resistance in aquatic environments, especially those used for recreational purposes. Significance and Impact of the Study: Although aquatic ecosystems play a vital role in human health, monitoring of antimicrobial resistance determinants and pathogens is frequently overlooked in such environments. Our study aimed to evaluate the presence of potentially pathogenic and antimicrobial‐resistant bacteria in a heavily polluted recreational estuarine ecosystem. Results constitute a basic understanding of resistant micro‐organisms in these waters and show a potential reservoir of antimicrobial resistance that could pose a serious threat to public health, highlighting the pertinence of extending water monitoring parameters to include the search of resistance and virulence determinants.