Bacterial infections and antimicrobial resistance cause significant mortality and morbidity. Extended-spectrum lactamases (ESBLs) are enzymes that help bacteria resist monobactams and cephalosporin. ESBLs hydrolyze cephalosporin and aztreonam and are inhibited by clavulanic acid. Gram- negative bacteria, K. pneumonia, E. coli, A. baumannii, and Pseudomonas spp. Linked to blood infections. ESBL acquisition is rising worldwide. ESBL-producing strains cause public health problems. ESBLs include blaTEM, blaSHV, and the blaCTX-M group. Study to assess antimicrobial resistance & frequency of ESBL genes from clinical samples at a hospital in Dera Ghazi Khan. Samples were collected and cultured. After identifying bacteria with Gram Staining and biochemical testing, we determined antimicrobial resistance and ESBL gene frequency. Salmonella typhi caused most cases of typhoid fever (48.2%), followed by Klebsiella pneumoniae (15.2%), Escherichia coli (10.7%), and Acinetobacter baumannii (9.8%). Less common pathogens were Serratia marcescens and Burkholderia cepacia (4.5% each). ESBLs gene prevalence was analyzed via primer- specific PCR and Gel Electrophoresis. 100% of marcescent isolates tested positive for blaTEM and K. Pneumonia with a high prevalence of blaTEM and blaSHV (88.2% and 64.7% respectively). E. coli carried prevalent blaCTX-M (83.3%), blaSHV (16.7%), and blaTEM (66.7%). This study focuses on strategies to limit the spread of antimicrobial resistance genes and find alternative treatments.

Index Terms- Extended spectrum–lactamases, Multidrug- resistant, blaCTX-M enzymes, Antibiotic-resistant