srjcmsSRJCMSSRJCMS2788-8851https://doi.org/10.47310/srjcms.2024.v04i01.004Incidence of Ampc -Lactamases Genes among Extensively Drug Resistant Pseudomonas Aeruginosa Isolated from Clinical Sources in Al-Najaf City-IraqAlaaHamza JaberAl-JelehawyQassimMuhsin HashimAl-FahamBackground: Pseudomonas aeruginosa is a main pathogens as a cause of healthcare acquired infection. This organism causes severe disaster of general health producing a great burden of mortality and morbidity in growing counties. AmpC-type enzymes are generally resistant to cephalosporins, but lower efficacy toward carbapenems. Nevertheless, carbapenem resistance is noted when AmpC enzymes combine with reduced carbapenem cell penetration due to a loss of porin protein. Overproduction of AmpC β-lactamases combinations occurring when associated with ESBLs and modified membrane channels leads to increasing carbapenem resistance of P. aeruginosa clinical isolates. Study Aim: This thesis is designed to identify and assess the frequency of P. aeruginosa clinical isolates, to examine the occurrence of extensively drug resistant P. aeruginosa in hospitals and to examine the presence of common AmpC β-Lactamases genes in XDR isolates in Najaf City-Iraq. Materials and Method: Basic test including stain of Gram, morphology of the colony and conventional biochemical test were used to isolate and identify clinical isolates of P.aeruginosa. Upon receipt, swab specimens were immediately cultured onto MacConkey agar and the plate were incubated for 24 hours at 37°C. Results: During 3-months, an overall of 1070 clinical specimens were collected from six main hospitals and Burn Center in Najaf province. Present results showed that 66 isolates of P. aeruginosa were obtained from clinical sources. The clinical sample type’s collected during the study period included 821 (76.6%) urine specimens from patients suspected with UTIs, 85 (7.9%) wound exudate, 71 (6.6%) ear swab, 56 (5.2 %) burn exudate and 37 (3.4%) CSF aspirates as shown in table (3-2). This study showed that 13 isolates from 66 isolates recognized as XDR P. aeruginosa isolates. This study showed that 13 (19.6%) isolates from 66 isolates recognized as XDR P. aeruginosa isolates. Among the 13 XDR isolates, PCR assay showed that all of these isolates harbored blaAmpC and blaCMY AmpC beta lactamase genes by using specific primers for each one.