Detection of Campylobacter spp. in farmed sheep in Mymensingh division of Bangladesh: Prevalence, risk factors, and antimicrobial susceptibility status

Abstract

Background and aim: Campylobacter infections in sheep may be asymptomatic or cause enteritis, ileitis, infertility, and abortion. Thus, this study aimed to estimate the prevalence of Campylobacter spp. in farming sheep and to detect risk factors, molecular patterns, and antimicrobial susceptibility status of these pathogens.

Materials and methods: Four hundred and eight fecal samples were collected from 12 flocks in the Mymensingh and Sherpur districts. Samples were tested by both basic (culture and biochemical tests) and molecular (initially 16S rRNA and later hipO gene-based polymerase chain reaction). Furthermore, the antimicrobial susceptibility status of Campylobacter jejuni was confirmed using disk diffusion. Flock- and animal-level data were captured using semi-structured interviews with farm owners under bivariate and multivariate logistic regression analyses to confirm the risk factors for Campylobacter-positive status.

Results: The prevalence of C. jejuni staining at the animal and flock levels was 8.82% (36/408) and 66.70% (8/12), respectively. The age of sheep was identified as an important risk factor. Up to 1 year of age, sheep were 3.78 times more likely to be infected with C. jejuni (95% confidence interval: 1.0736-13.3146, p = 0.038). Of the 36 isolates of C. jejuni, all were found to be fully susceptible (100%) to gentamicin and ciprofloxacin. In this study, three antimicrobial agents, oxytetracycline, azithromycin, and ceftriaxone, were fully resistant (100%). The majority of isolates were resistant to a combination of 4-6 antimicrobial agents.

Conclusion: The present study highlights the predominant maintenance of zoonotic Campylobacter species in sheep, and their burden on human health is enormous. Therefore, environmental, animal, and human health needs to be focused under a One Health lens to mitigate the occurrence of Campylobacter in farm settings and to prevent further introduction to animals and humans.

Keywords: antimicrobial resistance; campylobacter jejuni; identification; isolation; prevalence; risk factors; sheep.

Figure-1

Study districts (Mymensingh and Sherpur). A total of 12 farms (five from Sherpur district and seven from Mymensingh district) were included under this study (Source: The map was generated using ArcGIS version 10.3).

Figure-2

Detection of Campylobacter spp. by 16S rRNA gene-based polymerase chain reaction. Here, 1 and 9: 100 bp DNA ladder (Takara, Japan); Lane 4–8: Representative Campylobacter isolates of sheep origin; 3: Positive control (Campylobacter jejuni ATCC 33560); 2= Negative control.

Figure-3

Detection of Campylobacter jejuni by hipO gene-based polymerase chain reaction. Here, 1 and 9: 100 bp DNA ladder (Takara, Japan); 2: Negative control; 3: Positive control (C. jejuni ATCC 33560); Lane 4–8: Representative C. jejuni isolates of sheep origin.

Figure-4

Distribution of antimicrobial resistance pattern in Campylobacter jejuni isolates (n = 36) from sheep. ERY=Erythromycin, AMX=Amoxicillin, CRO=Ciprofloxacin, OTE=Oxytetracycline, AZM=Azithromycin, S=Streptomycin.