Journal Article

Antibiotic resistance profile and occurrence of AmpC between Pseudomonas aeruginosa isolated from a domestic full-scale WWTP in southeast Brazil

Paiva, Magna Cristina, Oliveira, Luiza Gerçossimo, Ferreira, Letícia Gonçalves Resende, Nascimento, Andrea Maria Amaral, Lima, William Gustavo, Dias, Marcela França, Reis, Mariana de Paula

2018

Overview

Wastewater treatment plants (WWTPs) represent an important reservoir of antibiotic resistance determinants. Although many studies have been conducted to evaluate resistance profiles in Enterobacteriaceae isolates from this setting, the dynamics of this phenomenon are poorly known to the bacterium Pseudomonas aeruginosa. Here we aimed to evaluate the resistance profiles and the production of AmpC β-lactamase in P. aeruginosa isolates from a domestic full-scale WWTP. Samples of the raw sewage and effluent were collected and the bacterium P. aeruginosa was isolated on cetrimide agar. Susceptibility to β-lactams, fluoroquinolones and aminoglycosides was evaluated by the disc diffusion method, and the presence of AmpC β-lactamase was investigated phenotypically and by molecular method. We recovered 27 isolates of P. aeruginosa. Of these, 81.5% were susceptible to all antimicrobials tested. However, a considerable rate of resistance to carbapenems (11%) was found among the isolates. Twenty-two isolates were positive in the phenotypic test for inducible AmpC β-lactamase but the blaampc gene was only identified in four isolates, suggesting the presence of other independent resistance mechanisms besides this β-lactamase. In summary, we have shown that P. aeruginosa isolates from a domestic WWTP represents a potential reservoir of blaampC genes and other resistance determinants, including those that result in low susceptibility to carbapenems and aminoglycosides.

• Publisher: IWA Publishing
• Subject: Aminoglycosides / Anti-Bacterial Agents - pharmacology / Antibiotic resistance / Antibiotics / Antimicrobial agents / Bacteria / Bacterial Proteins - metabolism / beta-Lactamases - metabolism / Brazil / Carbapenems / Cytochrome / Determinants / Disease resistance / Drug resistance / Drug Resistance, Bacterial / Dye dispersion / Dynamics / Effluents / Enterobacteriaceae / Enzymes / Fluoroquinolones / Genes / Humans / Laboratories / Methods / Microbial Sensitivity Tests / Molecular chains / Mortality / Mutation / Nosocomial infections / Plasmids / Profiles / Pseudomonas aeruginosa / Pseudomonas aeruginosa - drug effects / Pseudomonas aeruginosa - enzymology / Public health / Raw sewage / Reservoirs / Resistance mechanisms / Sewage / Sludge / Waste Disposal Facilities / Waste Disposal, Fluid / Waste Water / Wastewater / Wastewater treatment / Wastewater treatment plants / Water Microbiology / Water treatment