Genotyping of Indian antigenic, vaccine, and field Brucella spp. using multilocus sequence typing

Abstract

Introduction: Brucellosis is one of the most important zoonotic diseases that affects multiple livestock species and causes great economic losses. The highly conserved genomes of Brucella, with > 90% homology among species, makes it important to study the genetic diversity circulating in the country. Methodology: A total of 26 Brucella spp. (4 reference strains and 22 field isolates) and 1 B. melitensis draft genome sequence from India (B. melitensis Bm IND1) were included for sequence typing. The field isolates were identified by biochemical tests and confirmed by both conventional and quantitative polymerase chain reaction (qPCR) targeting bcsp 31Brucella genus-specific marker. Brucella speciation and biotyping was done by Bruce ladder, probe qPCR, and AMOS PCRs, respectively, and genotyping was done by multilocus sequence typing (MLST). Results: The MLST typing of 27 Brucella spp. revealed five distinct sequence types (STs); the B. abortus S99 reference strain and 21 B. abortus field isolates belonged to ST1. On the other hand, the vaccine strain B. abortus S19 was genotyped as ST5. Similarly, B. melitensis 16M reference strain and one B. melitensis field isolate were grouped into ST7. Another B. melitensis field isolate belonged to ST8 (draft genome sequence from India), and only B. suis 1330 reference strain was found to be ST14. Conclusion: The sequences revealed genetic similarity of the Indian strains to the global reference and field strains. The study highlights the usefulness of MLST for typing of field isolates and validation of reference strains used for diagnosis and vaccination against brucellosis.

Genetic Characterization of Animal Brucella Isolates from Northwest Region in China

“…Multilocus sequencing typing (MLST), as a genotyping tool for assessing genetic diversity and relationships, was widely used to identify and analyze diversity of bacteria and epidemiology characterization [ 5 – 8 ]. Although the data of MLST of Brucella stranis in China can not adequately reflect its epidemiological characteristics and relationship between disease emerging and development, the prevalence of genotypes of Brucella strains from Inner Mongolia has changed over time in the three stages [ 9 ].…”

Molecular epidemiological characteristics of Brucella in Guizhou Province, China, from 2009 to 2021

“…ST8 is the main prevalent genotype in Guizhou Province and China (Ma et al, 2016;Tian et al, 2017b;Cao et al, 2018b). It is widely distributed in Asia, Europe, and Africa, and it is also a popular genotype in foreign countries (Shome et al, 2016;Akar and Erganis, 2022;Dadar et al, 2022). ST2 of B. abortus in Guizhou Province is also the genotype of B. abortus widely epidemic in China (Piao et al, 2018).…”

Genome Sequencing and Comparative Genomics of Indian Isolates of Brucella melitensis

“…PubMLST also shows that out of the 11 B. melitensis strains from India, 7 isolates were typed as ST8, 2 were typed as ST12 (double locus variant of ST8), and 1 each belongs to ST11 and ST41, which both are single locus variant of ST8. Although the strain ADMAS-G1 was typed as ST7 by earlier workers, the epidemiological source for this isolate is not clear ( Shome et al, 2016 ).…”