# Identification and Antimicrobial Susceptibility of Mycoplasma capricolum subsp. capripneumoniae Isolates from China During 2024–2025

## TL;DR

This study identifies a new strain of Mycoplasma capricolum subsp. capripneumoniae in Chinese goats, which is genetically distinct and shows low antimicrobial resistance.

## Contribution

The discovery of a new Mccp lineage in China with close genetic ties to Middle Eastern isolates and its antimicrobial susceptibility profile.

## Key findings

- The Mccp isolates from China are genetically distinct from previous Chinese strains and closely related to isolates from Qatar and the UAE.
- Most isolates showed low antimicrobial resistance, but some were resistant to florfenicol and lincomycin.
- The isolates belong to a new lineage (Group 1, Lineage 1) that is spreading in China.

## Abstract

This study characterized Mycoplasma capricolum subsp. capripneumoniae (Mccp), the pathogen that causes contagious caprine pleuropneumonia (CCPP), in goats across China during 2024–2025. A total of 34 Mccp strains were isolated and analyzed. Genetic analysis showed that these strains are different from previous Chinese strains and are closely related to isolates from Qatar and the United Arab Emirates. These isolates generally showed low resistance to most antimicrobials, with several strains presenting resistance to florfenicol and lincomycin. These findings suggest a new type of Mccp is spreading in China, highlighting the need for continued monitoring and rational use of vaccines and drugs in goat farming.

Respiratory diseases induced by Mycoplasma species, mainly Mycoplasma capricolum subsp. capripneumoniae (Mccp) and Mycoplasma ovipneumonia (Mo), pose a major threat to goat/sheep farming. This study investigated the biological characteristics and antimicrobial susceptibility of Mccp isolates that suddenly spread extensively in China in the first half of 2024. A total of 34 Mccp isolates were obtained from goats with suspected contagious caprine pleuropneumonia (CCPP) across multiple provinces during 2024–2025. All isolates were purified and confirmed via a PCR targeting the arcD gene and exhibited characteristic “fried egg” colony morphology. Phylogenetic analysis based on the arcD gene and multi-locus sequence analysis (MLSA) of eight genetic loci revealed that the circulating strains shared high homology and belonged to Group 1 within Lineage 1, which showed a close genetic relationship with isolates from Qatar and the United Arab Emirates, while differing from previously reported strains in China. Antimicrobial susceptibility testing against nine antimicrobial drugs indicated that the Mccp isolates generally exhibited low resistance levels. However, some strains showed reduced susceptibility to florfenicol and lincomycin. These findings highlight the emergence of a genetically distinct Mccp lineage in China and underscore the importance of ongoing surveillance, strain characterization, and prudent antimicrobial use in CCPP control.