# Toxin genotypes and antimicrobial resistance profiles of Clostridium perfringens isolated from healthy and diseased goats in Jiangsu Province, China

## TL;DR

This study analyzed toxin types and antibiotic resistance in C. perfringens from goats in China, finding significant differences between healthy and diseased animals.

## Contribution

The study provides new insights into the toxin genotypes and AMR profiles of C. perfringens in goats, highlighting differences between healthy and diseased populations.

## Key findings

- Toxinotype A was most common in healthy goats, while toxinotypes D, C, and F were more frequent in diseased or deceased animals.
- High resistance to aminoglycosides and trimethoprim–sulfamethoxazole was observed, with all isolates remaining susceptible to vancomycin.
- Resistance genes like qnrS, tetA(P), and tetB(P) were more prevalent in isolates from diseased goats, especially toxinotype D.

## Abstract

Clostridium perfringens is a major enteric pathogen of goats, capable of producing multiple toxins and harboring diverse antimicrobial resistance (AMR) determinants. The coexistence of toxin diversity and AMR complicates disease control and poses risks to animal health and antimicrobial stewardship. This study aimed to characterize toxin genotypes, phenotypic AMR patterns, and associated resistance genes in C. perfringens isolates obtained from healthy, diseased, and deceased goats in Jiangsu Province, China.

A total of 404 samples were collected from goats between April 2021 and April 2022, including feces from healthy animals, rumen contents from slaughtered goats, and intestinal contents and visceral tissues from diseased or deceased goats. Isolation and identification of C. perfringens were performed using anaerobic culture and 16S rRNA gene sequencing. Toxin genotyping targeting major toxin genes was conducted by polymerase chain reaction (PCR). Antimicrobial susceptibility was assessed using the Kirby–Bauer disk diffusion method, and resistance genes were detected by PCR. Hierarchical clustering was used to explore relationships between toxinotypes and AMR gene profiles.

Ninety-four C. perfringens isolates were recovered (23.3%). Toxinotype A predominated overall (61.7%) and was dominant among healthy goats, whereas toxinotypes D (52.9%), C (14.7%), and F (14.7%) were more frequently detected in diseased or deceased animals. High phenotypic resistance was observed to aminoglycosides, including kanamycin (72.3%), neomycin (66.0%), and gentamicin (58.5%), as well as trimethoprim–sulfamethoxazole (61.7%). All isolates remained susceptible to vancomycin, with low resistance to β-lactams. Resistance genes associated with aminoglycosides, sulfonamides, tetracyclines, quinolones, and lincosamides were widely distributed. Notably, the quinolone resistance gene qnrS and tetracycline resistance genes tetA(P) and tetB(P) were significantly more prevalent in isolates from diseased goats, particularly toxinotype D.

Goat-associated C. perfringens in Jiangsu Province exhibits substantial toxin diversity and a high burden of AMR, with distinct differences between healthy and diseased animals. These findings underscore the need for continuous molecular surveillance, rational antimicrobial use, and integrated control strategies to mitigate risks to goat health and productivity within a One Health framework.