Frequency of class 1, 2 and 3 integrons in clinical Klebsiella pneumoniae isolates; a systematic review and meta-analysis of cross-sectional studies

Integrons are genetic elements containing gene cassettes transportable to other mobile genetic structures including plasmids in genome of bacteria. This study aimed to determine the prevalence of Integrons and correlation with antibiotic resistance in K. pneumoniae isolated from clinical samples of Iranian patients. The Medical Subject Headings (MeSH) of "Integrons", "Int1", "Int2", "Int3", "prevalence", "antibiotic resistance", "Klebsiella pneumoniae", and "Iran, with the aid of Boolean operators ("AND" or "OR") were used alone or in combinations to perform search process. We searched international databases (Cochrane Library, Scopus, MEDLINE, and ISI Web of Science) and search engines (PubMed, and Google Scholar). The search was limited to the literatures published in English from 1 January 2010 to 31 July 2019. Statistical analyses were performed using Comprehensive Meta-Analysis software (Version 3.3.070). The prevalence was presented by a 95% confidence interval (CI). Also, the P value< 0.05 was considered as the statistical significance threshold. Heterogeneity between studies was evaluated by Cochran's Q-test, and I-squared (I2) test. Thirteen high quality articles were included into the present review. Among them, five studies showed the correlation between Integrons and antibiotic resistance. The combined prevalence of Int1 was reported 52.4% (95% CI: 35.1-69.2). The pooled prevalence of Int2 was reported 8.8% (95% CI: 4.4-16.7). The combined prevalence of Int3 was reported 0%. The pooled prevalence of MDR K. pneumonia isolates was obtained as 90.2% (95% CI: 72.8-6.9). Our study showed a high prevalence of class 1 integrons, and also, the correlation between presence of integrons and antibiotic resistance.