# Antimicrobial Susceptibility of Campylobacter spp. Isolated from Cattle in Mongolia

## TL;DR

This study reports the first characterization of Campylobacter species in cattle in Mongolia, finding diverse strains with distinct antibiotic resistance patterns compared to chicken isolates.

## Contribution

The first characterization of Campylobacter spp. in cattle in Mongolia, revealing unique antimicrobial resistance patterns and genetic diversity.

## Key findings

- Thirty-five Campylobacter isolates were identified, including 23 C. jejuni, with substantial genetic diversity observed.
- Cattle C. jejuni isolates showed antimicrobial resistance patterns distinct from chicken isolates, with most being susceptible to tetracycline and ciprofloxacin.
- Sequence type ST61, associated with cattle and sheep, was identified among the isolates.

## Abstract

This study aimed to assess prevalence and antimicrobial resistance of Campylobacter spp. in cattle in Mongolia. Thirty-five Campylobacter spp., including 23 C. jejuni, 7 C. hyointestinalis, 4 C. fetus, and 1 C. lari, were isolated. Multilocus sequence typing of C. jejuni cattle isolates revealed substantial genetic diversity. The antimicrobial resistance patterns of the C. jejuni cattle isolates completely differed from those of previously reported chicken isolates; excluding one ciprofloxacin-resistant isolate, all C. jejuni isolates were susceptible to tetracycline and ciprofloxacin. To the best of our knowledge, this is the first report on the characterization of Campylobacter spp. in cattle in Mongolia.

Poultry and cattle are the major reservoirs of Campylobacter infection in humans. However, no information is available on Campylobacter spp. in cattle in Mongolia. Thus, this study aimed to assess their prevalence and antimicrobial resistance. Between 2019 and 2023, rectal swabs were collected from cattle on dairy farms around Ulaanbaatar city and in total, 35 Campylobacter spp., including 23 C. jejuni, 7 C. hyointestinalis, 4 C. fetus, and 1 C. lari, were isolated. Multilocus sequence typing of C. jejuni cattle isolates revealed substantial genetic diversity and identified 7 sequence types (STs) including ST61, which is known to be associated with cattle and sheep. Interestingly, the antimicrobial resistance patterns of the C. jejuni cattle isolates completely differed from those of previously reported chicken isolates. Excluding one ciprofloxacin-resistant isolate, all isolates were susceptible to tetracycline and ciprofloxacin. This is the first report on the characterization of Campylobacter spp. in cattle in Mongolia. Although no official statistics of human campylobacteriosis are currently available in Mongolia, data on Campylobacter spp. in food-producing animals represent valuable information for investigating potential sources and infection routes to humans.