AUTHOR=Ayoub Haris , Kumar M. Suman , Mehta Rishabh , Thomas Prasad , Dubey Muskan , Dhanze Himani , Ajantha Ganavalli S. , Bhilegaonkar K. N. , Salih Harith M. , Cull Charley A. , Veeranna Ravindra P. , Amachawadi Raghavendra G. 

TITLE=Exploring genetic determinants of antimicrobial resistance in Brucella melitensis strains of human and animal origin from India

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1474957

DOI=10.3389/fmicb.2024.1474957

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>Antimicrobial resistance (AMR) in <italic>Brucella melitensis</italic>, the causative agent of brucellosis, is of growing concern, particularly in low and middle-income countries. This study aimed to explore the genetic basis of AMR in <italic>B. melitensis</italic> strains from India.</p></sec><sec><title>Methods</title><p>Twenty-four isolates from humans and animals were subjected to antimicrobial susceptibility testing and whole-genome sequencing.</p></sec><sec><title>Results</title><p>Resistance to doxycycline (20.80%), ciprofloxacin (16.67%), cotrimoxazole (4.17%), and rifampicin (16.67%) was observed. Genome analysis revealed efflux-related genes like <italic>mprF</italic>, <italic>bepG</italic>, <italic>bepF</italic>, <italic>bepC</italic>, <italic>bepE</italic>, and <italic>bepD</italic> across all isolates, however, classical AMR genes were not detected. Mutations in key AMR-associated genes such as <italic>rpoB</italic>, <italic>gyrA</italic>, and <italic>folP</italic> were identified, intriguingly present in both resistant and susceptible isolates, suggesting a complex genotype–phenotype relationship in AMR among <italic>Brucella</italic> spp. Additionally, mutations in efflux genes were noted in resistant and some susceptible isolates, indicating their potential role in resistance mechanisms. However, mutations in AMR-associated genes did not consistently align with phenotypic resistance, suggesting a multifactorial basis for resistance.</p></sec><sec><title>Discussion</title><p>The study underscores the complexity of AMR in <italic>B. melitensis</italic> and advocates for a holistic multi-omics approach to fully understand resistance mechanisms. These findings offer valuable insights into genetic markers associated with AMR, guiding future research and treatment strategies.</p></sec>