AUTHOR=Cooke Deborah M. , Clarke Charlene , Kerr Tanya J. , Warren Robin M. , Witte Carmel , Miller Michele A. , Goosen Wynand J. 

TITLE=Detection of Mycobacterium bovis in nasal swabs from communal goats (Capra hircus) in rural KwaZulu-Natal, South Africa

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1349163

DOI=10.3389/fmicb.2024.1349163

ISSN=1664-302X

ABSTRACT=<p>Animal tuberculosis, caused by <italic>Mycobacterium bovis</italic>, presents a significant threat to both livestock industries and public health. <italic>Mycobacterium bovis</italic> tests rely on detecting antigen specific immune responses, which can be influenced by exposure to non-tuberculous mycobacteria, test technique, and duration and severity of infection. Despite advancements in direct <italic>M. bovis</italic> detection, mycobacterial culture remains the primary diagnostic standard. Recent efforts have explored culture-independent PCR-based methods for identifying mycobacterial DNA in respiratory samples. This study aimed to detect <italic>M. bovis</italic> in nasal swabs from goats (<italic>Capra hircus</italic>) cohabiting with <italic>M. bovis</italic>-infected cattle in KwaZulu-Natal, South Africa. Nasal swabs were collected from 137 communal goats exposed to <italic>M. bovis</italic>-positive cattle and 20 goats from a commercial dairy herd without <italic>M. bovis</italic> history. Swabs were divided into three aliquots for analysis. The first underwent GeneXpert® MTB/RIF Ultra assay (Ultra) screening. DNA from the second underwent mycobacterial genus-specific PCR and Sanger sequencing, while the third underwent mycobacterial culture followed by PCR and sequencing. Deep sequencing identified <italic>M. bovis</italic> DNA in selected Ultra-positive swabs, confirmed by region-of-difference (RD) PCR. Despite no other evidence of <italic>M. bovis</italic> infection, viable <italic>M. bovis</italic> was cultured from three communal goat swabs, confirmed by PCR and sequencing. Deep sequencing of DNA directly from swabs identified <italic>M. bovis</italic> in the same culture-positive swabs and eight additional communal goats. No <italic>M. bovis</italic> was found in commercial dairy goats, but various NTM species were detected. This highlights the risk of <italic>M. bovis</italic> exposure or infection in goats sharing pastures with infected cattle. Rapid Ultra screening shows promise for selecting goats for further <italic>M. bovis</italic> testing. These techniques may enhance <italic>M. bovis</italic> detection in paucibacillary samples and serve as valuable research tools.</p>