Antimicrobial Resistance Profiles and Virulence Genes of Pseudomonas Aeruginosa Isolates Originated From Hospitalized Patients in Shiraz, Iran

Introduction: multidrug-resistant (mdr) pseudomonas aeruginosa isolates are among the common cause of nosocomial infections. in p. aeruginosa infections, several genes, mexa, and mexb are involved in resistance to antibiotics and psla, pela and brlr contribute to biofilm formation. this study aims to investigate the prevalence of these genes in p. aeruginosa isolates and to determine their relationship with biofilm formation, antibiotic resistant, pigment production, and source of infection. methods: we collected 63 specimens out of 90 samples from patients hospitalized in a hospital affiliated to shiraz university of medical sciences. the specimens belonged to 42 men and 21 women and included urine, sputum, wound, skin, blood, body fluid, and central venous blood (cvb). the samples were cultured on solid media and diagnosed according to standard phenotypic characteristics. disk diffusion method was used to identify the clinical mdr p. aeruginosa isolates, and the genes psla, pela, brlr, mexa, and men were detected by pcr. results: about 25.4% of the clinical isolates were mdr, i.e., resistant to three or more antibiotics. the prevalence of the genes in the clinical isolates was as follows: psla (92.1%), pela (68.3%), brlr (93.7%), mexa (95.2%) and mexb (50.8%). the highest and lowest prevalence of drug resistance belonged to ceftriaxone and amikacin, respectively. the highest mdr p. aeruginosa isolates originated from wound, urine and sputum specimens. conclusion: the presence of mdr isolates correlated significantly with the patients’ gender, the origin of specimens, and bacterial pigment production. in this study, the detected genes did not significantly correlate with the mdr features of the isolates.