# 2002–2022 Quinolone Resistance in Escherichia coli of Swine in Mainland China: A Meta-Analysis

## TL;DR

This study analyzed quinolone antibiotic resistance in swine-derived Escherichia coli in China from 2002 to 2022, finding high resistance rates and highlighting public health risks.

## Contribution

The study provides a comprehensive meta-analysis of quinolone resistance trends in swine E. coli in China, revealing regional and temporal patterns.

## Key findings

- Enrofloxacin had the highest resistance rate at 54%, followed by ciprofloxacin at 50%.
- Resistance rates were higher in eastern China compared to western regions.
- Restrictions on quinolone use since 2016 did not significantly reduce resistance rates.

## Abstract

In this study, we assessed the evolution of resistance to quinolone antibiotics in swine-derived Escherichia coli in mainland China from 2002 to 2022 by meta-analysis. Fifty-three studies were included after systematic searches of PubMed, Web of Science, and CNKI databases, and the resistance rates were calculated using random-effects models and Freeman–Tukey double-orthogonal string transformation. The results showed that the overall resistance rates of the four quinolone antibiotics were, in order, enrofloxacin (54%), ciprofloxacin (50%), ofloxacin (43%) and levofloxacin (37%). Subgroup analyses showed that the resistance rate was significantly higher in the eastern region than in the western region, but there was no significant change in the resistance rate before and after 2018, and the testing method did not significantly affect the results. Although China has restricted the use of some quinolone veterinary drugs since 2016, the resistance rate did not decrease significantly, which may be related to the continued use of alternative drugs and the diverse spread of resistance genes. This study reveals the critical situation of quinolone resistance in swine-derived E. coli, highlights the public health risk of the cross-species transmission of resistance genes, and provides an important basis for optimizing veterinary antibiotic management.

Swine have emerged as significant reservoirs of antibiotic-resistant strains and genes. To establish a sound rationale for applying quinolone antibiotics in the swine industry, a meta-analysis was performed on the resistance rate of swine-derived Escherichia coli to quinolone antibiotics in China from 2002 to 2022. We systematically searched through three databases, PubMed, Web of Science, and CNKI, and included 53 eligible studies within the specified timeframe. Resistance rates were calculated using a random-effects model and the Freeman–Tukey double-arcsine transformation. The resistance rates observed were as follows: 37% for levofloxacin (95% CI: 27~47%), 43% for ofloxacin (95% CI: 34~51%), 54% for enrofloxacin (95% CI: 46~62%), and 50% for ciprofloxacin (95% CI: 42~58%). Further subgroup analyses illuminated that the resistance rates were higher in mainland China’s eastern regions than in western regions. Additionally, there was no significant decrease in the resistance rate over time in different periods. From 2002 to 2022, Escherichia coli strains from swine in various regions of mainland China exhibited differing degrees of generalized resistance to quinolones. This poses a potential public health risk and underscores the fact that the control of quinolone antibiotics remains a prolonged and ongoing challenge.