One Health Molecular Surveillance of Zoonotic Bacteria and Antimicrobial Resistance in Slaughterhouses in Accra, Ghana

Abstract

Surveillance of zoonotic diseases often does not fully integrate One Health approaches in high risk environments. This contributes to underreporting and limited preliminary data for neglected zoonoses while leaving humans exposed to potentially harmful bacterial pathogens. This study applied a One Health molecular surveillance approach in three slaughterhouses in Accra, Ghana, where environmental swabs, passive air samples, domestic ruminant blood, and human blood were collected. Bacteria were identified using Matrix-Assisted Laser Desorption/Ionization Time-Of Flight Mass Spectrometry (MALDI-TOF-MS) and 16S rRNA metagenomic sequencing for culture-dependent and culture-independent samples respectively. Selected zoonotic isolates were assessed for antimicrobial resistance (AMR) using Kirby Bauer disc diffusion and microbroth dilution assays with 12 antibiotics and polymerase chain reaction targeting 14 AMR genes, respectively. Risk of exposure among slaughterhouse workers was evaluated through questionnaires and focus group discussions. Twelve bacterial species were identified using MALDI-TOF-MS and 236 unique species were detected by metagenomic sequencing. Nearly one third of all identified bacteria were zoonotic and included species prioritized by the World Health Organization or Ghana. All 20 selected zoonotic bacteria displayed multidrug resistance with four distinct resistance patterns, a multiple antibiotic resistance index of 0.90, and an average resistance of 89.97%. Identical AMR markers were observed in bacteria from animals and humans. The risk of exposure was comparable across facilities, but each facility required tailored mitigation strategies. The study demonstrates the feasibility of applying a One Health molecular surveillance approach to identify bacterial diversity, zoonotic potential, and AMR in slaughterhouse settings, providing data that can inform targeted interventions and guide local antimicrobial stewardship programmes.