Risk of type III secretion systems in burn patients with Pseudomonas aeruginosa wound infection: A systematic review and meta-analysis

The pathogenesis of Pseudomonas aeruginosa is multifactorial and attributed to the production of several cell-associated and extracellular virulence factors including those implicated in adherence, iron uptake, exoenzymes (Exo) and exotoxins. The present study aimed to determine the prevalence of type III secretion systems (T3SS) effectors in Iranian burn patients with P. aeruginosa wound infection.

A systematic search was conducted to identify papers published by Iranian authors in the Web of Science, PubMed, Scopus, Embase, and Google Scholar electronic databases during the period of January, 2000 to December, 2018. Publications which met our inclusion criteria were selected for data extraction and analysis by Comprehensive Meta-Analysis Software. The inclusion criteria were articles that include burn patients with a wound infection caused by P. aeruginosa, and reported the prevalence of aimed exoenzymes.

Ten publications were selected out of 15 full-text reviewed articles with the inclusion criteria. Of ten studies, the pooled prevalence of ExoS producing isolates was estimated at 57.1% (95% CI: 40.3-72.5%). Five studies reported the prevalence of ExoU and ExoT, from which, the pooled prevalence of ExoU and ExoT producing isolates was estimated at 51.4% (95% CI: 31.4-70.9%) and 86.4% (95% CI: 48.1-97.8%), respectively. Four studies reported the prevalence of ExoY, from which, the pooled prevalence of ExoY producing isolates was estimated at 79.0% (95% CI: 48.6-93.8%).

Our results showed a remarkable prevalence of T3SS-positive genotype in patients with burn injuries. These findings provided attractive targets for new therapeutic strategies for burn patients who were infected with cytotoxin-producing P. aeruginosa.