Multi-drug resistant Gram-negative bacteria in wastewater treatment plants : -With focus on Acinetobacter baumannii complex

Abstract: Multidrug-resistant (MDR) pathogens are emerging problems humanity faces today. Increasing MDR Gram-negative bacteria is not only a threat towards humanity itself but also towards food safety. The genus Acinetobacter is an environmental bacterium that can be found in habitats, including aquatic environments, soil, wastewater, food, and animals. Acinetobacter spp. is naturally resistant to a broad spectrum of antibiotics and quickly develop resistance due to their OXA β-lactamases enzyme set. Their broad-spectrum resistance makes infections caused by Acinetobacter hard to treat. The study aimed to investigate if there are any Acinetobacter spp. in the wastewater treatment plants (WWTP) in Sweden with focus on A. baumannii. The study also checked for antibiotic resistance in Acinetobacter isolates. Four sample sites in Sweden were chosen to investigate for the persistence of Acinetobacter spp. in both incoming and outgoing wastewater. Through antibiotic susceptibility testing, it was confirmed that the majority of Acinetobacter spp. were resistant towards antibiotic groups, carbapenem, aminoglycosides, folic acid synthesis inhibitors, and suspected resistance towards cephalosporins. It was also concluded that the WWTPs might have an impact on decreasing the amount of Acinetobacter spp. released into the environment.