Prevalence and Phenotypic and Genotypic Resistance Mechanisms of Multidrug-Resistant Pseudomonas aeruginosa Strains Isolated from Clinical, Environmental, and Poultry Litter Samples from the Ashanti Region of Ghana

Abstract

Background. Antibiotic resistance in bacteria is a major global health challenge. Reports on the prevalence of multidrug-resistant P. aeruginosa, a common pathogenic bacterium implicated in nosocomial infections and poultry diseases, are limited in Ghana. This study therefore sought to determine the prevalence of P. aeruginosa from hospitals, poultry farms, and environmental samples from the Ashanti region of Ghana. Methodology. Stool, urine, and blood samples from 364 patients from two hospitals in the Ashanti region of Ghana were randomly sampled. P. aeruginosa was isolated and confirmed using routine selective media and PCR-based oprL gene amplification. The Kirby-Bauer disk diffusion method employing EUCAST breakpoint values was used to identify multidrug-resistant strains. The occurrence of common antibiotic inactivating enzymes and resistance encoding genes and the assessment of strain efflux capacity were investigated with double disc synergy test (DDST), imipenem-EDTA synergy test, phenylboronic acid test, D-test, routine PCR, and ethidium bromide agar-cartwheel method. Results. A total of 87 (9.7%, n = 87/900) P. aeruginosa isolates were confirmed from the samples. 75% (n = 65/87) were resistant to more than one group of antipseudomonal agents, while 43.6% (n = 38/87) were multidrug-resistant (MDR). High prevalence of extended spectrum β-lactamases (84.2%), metallo-β-lactamases (34.1%), and AmpC inducible cephalosporinases (50%) was observed in the MDR strains. About 57.8% of the MDR strains showed moderate to very high efflux capacity. Class 1 integrons were detected in 89.4% of the MDR isolates but β-lactamase encoding genes (blaSHV, blaTEM, blaCTX-M, blaVIM, and blaIMP) were not detected. Conclusion. Surveillance of antibiotic-resistant strains of bacteria should be routinely conducted in clinical and veterinary practice in Ghana to inform selection of antibiotics for therapeutic use.