Global prevalence of Salmonella spp. and Escherichia coli in reptile taxa: a systematic review and meta-analysis

Background Reservoirs of zoonotic agents have been well-described in reptiles; however, global consensus across reptile taxa is lacking. In this systematic review and meta-analysis, the global prevalence of Salmonella spp. and Escherichia coli were estimated in reptiles to provide an overview of their occurrence and potential public health relevance. Methods The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were adhered to. Five online databases PubMed, Scopus, ScienceDirect, Google Scholar, and Medline were thoroughly searched to conduct meta-analyses. Data on prevalence were pooled using the random-effects model and heterogeneity was quantified using I 2 statistics to ensure robustness of the data. Further, the publication bias was carefully assessed by Egger’s linear regression and Begg’s rank correlation tests. Results The pooled prevalence of Salmonella spp. and Escherichia coli was examined using Comprehensive Meta-Analyses software v4.0. A total of 189 studies met the criteria for inclusion in this meta-analysis. Across these studies, a combined total of 24,152 specimens were assessed, resulting in the evaluation of 5,046 E. coli and Salmonella spp. isolates. The overall pooled prevalence of E. coli and Salmonella spp. was 25.1% (95% CI: 18.9–32.5%) and 33.3% (95% CI: 29.3–37.5%), respectively. Lizards exhibited the highest pooled prevalence at 36.8% (95% CI: 21.5–55.4%), while snakes showed the lowest prevalence at 16.8% (95% CI: 8.7–29.9%). Regarding geographic distribution, the highest pooled prevalence occurred in Indonesia, reaching 98.7% (95% CI: 88.1–99.9%) for Salmonella spp. and an identical 98.7% (95% CI: 88.1–99.9%) for E. coli . Subgroup analysis by sample type revealed that the highest pooled prevalence of Salmonella spp. was documented in composite fecal samples, reaching 45.8% (95% CI: 32.5–59.8%). Conversely, for E. coli , the highest pooled estimate was derived from isolated fecal samples at 40.5% (95% CI: 7.6–84.9%). Methodological subgroup analysis revealed that the combination of culture and serotyping resulted in the highest pooled prevalence for Salmonella spp. at 48.1% (95% CI: 35.6–60.9%). On the contrary, the highest pooled prevalence of E. coli was 50.3% (95% CI: 32.2–68.3%) obtained from the studies using a combination of culture, biochemical testing and serotyping. Conclusion A high global colonization burden of Salmonella spp. and E. coli exists in reptiles with significant variation by host taxonomy, geography and diagnostic method, and highlight the widespread occurrence of these bacteria in reptiles and their potential as zoonotic significance.