Survey and typing of Pseudomonas aeruginosa strains causing nosocomial infection using multiple-locus variable number tandem repeat analysis

Abstract

Background and Aim: Identification of the source of Pseudomonas aeruginosa (P. aeruginosa) as cause of nosocomial infections is an important step towards infection control. The purpose of this study was to perform multiple-locus variable number tandem repeat survey and analysis for typing of P. aeruginosa as a cause of nosocomial infection. Material and Methods: This descriptive-analytic study included 134 clinical samples of P. aeruginosa in Sanandaj from December 2015 to August 2017. Phenotypic tests and PCR were performed to confirm P. aeruginosa. Molecular typing was carried out by variable number of tandem repeats (VNTR), and analysis was performed using a zero-and-one matrix. Using Stata 12, data were analyzed by chi-square and Fisherchr('39')s exact tests (p≤0.05). Results: 41.79% of P. aeruginosa strains were associated with nosocomial infections. The highest number of clinical specimens were related to tracheal (51.78%) and the least number associated with sputum and abdominal fluid (each one1.78%). There was a significant relationship between nosocomial infections and intensive care unit (ICU) (p≤0.05). Also nosocomial infections showed a significant relationship with tracheal samples (p≤0.05). Analysis of 10 strains isolated from nosocomial infections showed 10 patterns with a similarity of 72%. Conclusion: Nosocomial infections were related to P. aeruginosa and we showed epidemiological distributions of this bacterium in our study. Identification of the origin of the bacteria responsible for nosocomial infections is an important step in the prevention and control of these infections.

Keywords

• multiple-locus variable number tandem repeat
• pseudomonas aeruginosa
• nosocomial infections