The prevalence of amphenicol resistance in Escherichia coli isolated from pigs in mainland China from 2000 to 2018: A systematic review and meta-analysis

BackgroundAmphenicols have been widely used in the pig industry in China, leading to varying degrees of drug resistance.MethodsThe systematic review was performed according to PRISMA (Preferred Reported Items for Systematic Reviews and Meta-Analysis) recommendations on studies investigating the prevalence of amphenicol-resistant Escherichia coli (E. coli) isolated from pig in mainland China from 2000 to 2018, a random-effects model was selected, then followed by meta-analysis.ResultsA total of 103 articles were included in the study. The results of the meta-analysis revealed that the pooled summarized prevalence of resistance to chloramphenicol (CAP) was 72.31% (95% confidence interval (95% CI) = 67.12%–77.23%) and to florfenicol (FF) was 58.64% (95% CI = 52.48%–64.67%). During the past 18 years, the resistance rate to CAP remained high initially but then declined rapidly after 2012, whereas the resistance rate to FF plateaued (54.13%–59.60%) from 2000–2018. In different parts of China, the rate of resistance to amphenicols among E. coli isolates was fairly consistent, with the exception of the north and northwest regions.ConclusionsIn 2002, the veterinary use of CAP was prohibited and its resistance levels in E. coli isolated from pigs was initially maintained at a high level but then showed an obvious downward trend in recent years. Resistance to commonly used FF remained at a high but stable level.