Phenotypic detection of efflux pumps and biofilm formation in multidrug-resistant bacteria isolated from surgical wound infections

Aims: This study investigates the presence of efflux pumps in multidrug-resistant bacterial isolates from surgical wound infections. Methodology and results: The current study isolated and identified multiple antibiotic-resistant bacteria from surgical wound infections. Among 90 bacterial isolates, all showed considerable resistance to many antibiotics used in this study. Among the most resistant bacteria were Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Proteus spp. and Citrobacter spp. The resistance ranged between 75% and 100%. This was followed by Klebsiella spp. It ranged from 50% to 58.3%, while the lowest was in Staphylococcus aureus 25% and Enterobacter cloacae 33.3%. Seven resistant isolates (15.21%) tested positive for EtBrCW using the phenotypic efflux pump by the EtBr cartwheel method, and fourteen (30.43%) were EtBrCW-intermediate. In contrast, the remaining resistant isolates (54.3%) showed negative results for this test. Though testing the isolates for biofilm formation using Congo red agar method, it was found that 39.5% showed promising activity, 11.6% showed intermediate training and the rest were negative. 22.7% of isolates with biofilm-forming activity had positive efflux pump results and 22.7% showed intermediate efflux pump results. Conclusion, significance and impact of study: It is concluded that efflux pumps play a significant role in drug resistance because the majority of our isolates were MDR and have phenotypic efflux pumps when exposed to UV light bacteria with efflux pumps were able to pump ethidium bromide to the medium, and we deduced this since there was no fluorescent signal at low concentrations of EtBr. Moreover, there is a relationship between biofilm formation and the presence of efflux pumps. However, more investigation is required to determine EPIs. In addition, altering efflux genes' expression can be done using Real-time PCR to confirm their outcomes in vivo.