Wiriyaprom, R. | bioRxiv Science

bioRxiv2026

Genetic diversity and antimicrobial susceptibility pattern of Shiga toxin-producing Escherichia coli and Campylobacter spp. isolated from healthy goats in southern Thailand

Foodborne illness is a significant public health concern worldwide. Shiga toxin-producing Escherichia coli and Campylobacter species are recognized as important zoonotic bacterial pathogens contributing to human infections through the food chain, particularly via foods of animal origin. Although goat meat is in high demand in the southern region of Thailand, studies on foodborne pathogens in this livestock species remain limited. The current study aimed to (i) determine the antimicrobial susceptibility of Campylobacter spp. and STEC isolated from goats, and (ii) analyze the genetic relationships among Campylobacter spp. And E. coli O157 isolates obtained from different sources. Campylobacter jejuni and C. coli isolates were characterized based on sequences of seven housekeeping genes using the Achtman multilocus sequence typing scheme. For E. coli O157:H7, core genome multilocus sequence typing analysis was performed using whole-genome sequencing data. Genetic diversity was observed among C. jejuni, whereas a clonal population structure was detected in C. coli and E. coli O157:H7. Overlapping genetic characteristics were observed between C. jejuni isolates from goats and those previously reported in livestock and humans in Thailand. Among Campylobacter species, resistance to fluoroquinolones, including ciprofloxacin and nalidixic acid, was observed, whereas resistance to fosfomycin was most frequently detected in Shiga toxin-producing E. coli. Tetracycline-resistant isolates were identified in both Campylobacter species and Shiga toxin-producing E. coli at moderate levels. A multidrug-resistant pattern was observed only in C. coli, whereas no multidrug-resistant C. jejuni or Shiga toxin-producing E. coli isolates were detected. These findings indicate that healthy goats may serve as potential reservoirs of zoonotic pathogens and antimicrobial resistance in southern Thailand, where goat meat is frequently consumed.

microbiology↗

bioRxiv2024

Whole-genome sequencing of Hyphopichia burtonii from isolated yeast recovered from zebra dove droppings in Thailand

This study aimed to characterise zoonotic yeasts from zebra dove (Geopelia striata) droppings in small farms in Songkhla province, Thailand. Four contaminated isolates were found with morphology and biochemical test results like those of Cryptococcus spp., but they exhibited different results from the positive control in nested polymerase chain reaction (PCR); the first step was negative, but the nested PCR step was positive. All isolates were subjected to antifungal susceptibility testing. The resistance isolate (Tip11) was subjected to whole genome sequencing. Only the Tip11 isolate showed high resistance to itraconazole and ketoconazole, with minimum inhibitory concentrations of >32.0 and 32.0 g/mL, respectively, corresponding to high levels of minimum fungicidal concentrations for both drugs (>32 g/mL). Consequently, Tip11 was selected as a representative of the contaminated isolates and subjected to whole-genome sequencing analysis. The results identified the Tip11 isolate as Hyphopichia burtonii (99.30% identity), with a genome length of 12,360,159 bp, a GC content of 35.16%, and 2,146 protein groups closely related to the Saccharomycetaceae family. This is the first report of H. burtonii in zebra doves in Thailand. This yeast has been previously identified as a cause of human infection leading to peritonitis in Thailand, and its resistance to antifungal drugs may pose a public health risk. Therefore, the application of biosecurity measures on farms, such as regular removal of droppings and cage sanitisation, should be implemented according to good agricultural practices. Moreover, further characterisation and functional analysis of the proteins identified should be considered.

molecular biology↗