Study of molecular epidemiology of anthrax in livestock in Karnataka Shashikala N1, Isloor S1,*, Kavitha G2, Rathnamma D1, Leena G3, Chandranaik BM2, Singh Shraddha1, Veeregowda BM1, Shivraj M2 1Department of Veterinary Microbiology, Veterinary College, KVAFSU, Hebbal, Bengaluru, Karnataka, India 2IAH and VB, KVAFSU, Hebbal, Bengaluru, Karnataka, India 3Department of Veterinary Public Health, Veterinary College, KVAFSU, Hebbal, Bengaluru, Karnataka, India *Corresponding author E-mail id: kisloor@gmail.com
Onilne Published on 8 March, 2024. Abstract Anthrax is a contagious and highly fatal zoonotic bacterial disease affecting primarily herbivores. Detection of Bacillus anthracis is challenging due to its genetic similarity to Bacillus cereus. The present study employed microscopy (Gram and polychrome methylene blue staining methods) and PCR for the detection of B. anthracis. Clinical specimens from suspected animals/carcasses and soil samples (from 6 districts of Karnataka) were collected. The virulent plasmid-mediated genes (pXO1 and pXO2) for protective and capsular antigens, respectively, were targeted for B. anthracis; Ba813 gene of B. anthracis and nhe gene of B. cereus were targeted for species-specific identification. Sixteen out of 18 blood smears were positive for anthrax bacilli by staining, but only 4 smears revealed PCR positivity. Further, out of 10 blood samples, 5 were PCR positive. None of the 5 ear pieces and 5 soil samples were found positive by PCR. The B. cereus isolate (repository) showed amplification for both pXO1 and nhe genes. Sequencing and phylogenetic analysis revealed that the pXO1 gene sequences of the B. cereus were homologous to that of B. anthracis, indicating close genetic relatedness between the two. High genetic homology (98%) among B. anthracis isolates was revealed. Ba813 and pXO2 gene-based phylogenetic analysis indicated the probable prevalence of two strains of B. anthracis in the outbreak of anthrax in Bellary. Top Keywords Anthrax, B. anthracis, B. cereus, pXO1 and pXO2 genes. Top |