PCR identification and automated ribotyping of Pseudomonas aeruginosa clinical isolates from intensive care patients

Arif Sarwari, Rumina Hasan, Chuan Bian Lim, Yvonne Ng, Charis Ng, Sara Zaman

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


Nosocomial isolates of Pseudomonas aeruginosa exhibit high rates of resistance to antibiotics, and are often multidrug resistant. P. aeruginosa clinical isolates (n = 56) were obtained from ICU patients in a hospital in Pakistan over a 3-y period. Antimicrobial susceptibility of the 56 P. aeruginosa clinical isolates was investigated using 7 antibiotics and the resistance rates were as follows: aztreonam (68% resistant), ceftazidime (67%), imipenem (66%), ofloxacin (59%), amikacin (56%), gentamicin (44%), and piperacillin-tazobactam (27%) (p < 0.01). In addition, 55% of the P. aeruginosa clinical isolates were resistant to 4 or more antibiotics. Imipenem-resistant strains were frequently associated with ceftazidime, ofloxacin, aztreonam, and more strikingly, amikacin resistance (p < 0.05). PCR (using P. aeruginosa-specific primers VIC1 +VIC2 and P1 +P2, respectively) was highly specific and sensitive, and was positive for all 56 P. aeruginosa isolates tested. Automated ribotyping was used to investigate the clonal diversity of the 56 P. aeruginosa isolates. Automated ribotyping indicated that the clinical isolates were clonally related and could be clustered into 4 major ribogroups based on their similarity index, with ribogroup II being the dominant one. The P. aeruginosa isolates in ribogroup II were correlated with their antibiotic resistance pattern and, interestingly, there seemed to be a gradual acquisition of multiple antibiotic resistance associated with the isolates within this group over time. The ribotyping data, together with the antibiotic resistance profile, provide valuable molecular epidemiology information for the control of hospital-acquired P. aeruginosa infections.

Original languageEnglish
Pages (from-to)342-349
Number of pages8
JournalScandinavian Journal of Infectious Diseases
Issue number5
Publication statusPublished - 2004


Dive into the research topics of 'PCR identification and automated ribotyping of Pseudomonas aeruginosa clinical isolates from intensive care patients'. Together they form a unique fingerprint.

Cite this