Molecular characterization of multidrug resistant (MDR) clinical isolates of Pseudomonas aeruginosa from Nsukka, South Eastern Nigeria

Background: P. aeruginosa is an important nosocomial pathogen with increasing resistance to antibiotics. Objective: This studywas performed to evaluate the genetic relatedness of MDR clinical isolates of P. aeruginosa. Method: A total of 1000 samples were analysed in the study. Antibiotic resistance profiles of the isolates were determined usingKirby Bauer disk diffusion method. Polymerase chain reaction (PCR) and sequencing were simultaneously used to detect theconsensus region of 16S rRNA. Genetic relatedness of the isolates was determined using restriction patterns from ALU 1 digestand random amplified polymorphic DNA. Results: Out of the 192 P. aeruginosa isolates recovered, 136 (78.83%) were multidrug resistant. Sequence analysis of the confirmedisolates (80.68%) revealed that all the isolates shared homology with each other and also showed sequence similarity toknown strains of P. aeruginosa (ATCC 27853; KT 315654; KU 321274 and KT894767). The PCR-Restriction fragment lengthpolymorphism (PCR-RFLP) analysis revealed that there was a lot of genetic relatedness among the isolates. The RFLP fingerprinting technique detected seven distinct RFLP types among the isolates. Conclusions: Thus, study shows that there is high prevalence of MDRPA and high degree of genetic relatedness among theMDRPA isolates circulating in Nsukka area. Keywords: MDRPA; PCR-RFLP; RAPD; Sequencing; 16S rRNA gene.