Extended Spectrum Beta Lactamase-Producing Pseudomonas aeruginosa: Phenotypic Identification and Antimicrobial Resistance Pattern

Background: Pseudomonas aeruginosa is the most prevalent Gram-negative bacteria associated with nosocomial infections.It is therefore necessary to study its trend of antimicrobial resistance.Few therapeutic alternatives are available as Extended spectrum Beta lactamases (ESBL)-producing organisms exhibit co-resistance to several antibiotics' classes.To study's aim is to study the prevalence, ESBL production, and resistance pattern of P. aeruginosa isolates obtained from respiratory samples employing phenotypic methods.Methods: This study was conducted on 560 clinical respiratory samples from patients presented to the School of Excellence in Pulmonary Medicine, NSCB Medical College, Jabalpur, India.It was a prospective study conducted in the Department of Microbiology on 100 P. aeruginosa samples obtained from respiratory samples of both patient's in-patient department (IPD) and out-patient department (OPD).Result: Among the 560 samples subjected to identification and isolation of aerobic growth, 385 samples were positive for bacterial growth.Of these, 100 (26%) samples were positive for P. aeruginosa.Antibiotic sensitivity pattern was determined for all the isolated strains.P. aeruginosa isolates showed maximum resistance to ticarcillin/clavulanic acid (79%), aztreonam (78%), and ceftazidime (74%).However, P. aeruginosa strains showed maximum sensitivity to piperacillin/tazobactam (88%).The same isolates were also examined using the double disc synergy method for phenotypic characterization of ESBL against ceftazidime and clavulanic acid using the CLSI standards.About 49% of the resistant P. aeruginosa strains isolated from sputum samples were positive for ESBL. Conclusion:The current work strongly suggests further research on P. aeruginosa antibiotic-resistant strains for ESBL phenotypic characterization.