Background: Brucellosis is an infectious disease caused by bacteria of the genus Brucella. Although it is the most common zoonosis worldwide, there are increasing reports of drug resistance and cases of relapse after long term treatment with the existing drugs of choice. This study therefore aims at identifying possible natural inhibitors of Brucella melitensis Methionyl-tRNA synthetase through an in-silico approach. Methods: Using PyRx 0.8 virtual screening software, the target was docked against a library of natural compounds obtained from edible African plants. The compound, 2-({3-[(3,5-dichlorobenzyl) amino] propyl} amino) quinolin-4(1H)-one (OOU) which is a co-crystallized ligand with the target was used as the reference compound. Screening of the molecular descriptors of the compounds for bioavailability, pharmacokinetic properties, and bioactivity was performed using the SWISSADME, pkCSM, and Molinspiration web servers respectively. The Fpocket and PLIP webservers were used to perform the analyses of the binding pockets and the protein ligand interactions. Analysis of the time-resolved trajectories of the Apo and Holo forms of the target was performed using the Galaxy and MDWeb servers. Results: The lead compounds, Strophanthidin and Isopteropodin are present in Corchorus olitorius and Uncaria tomentosa (Cat’s-claw) plants respectively. Isopteropodin had a binding affinity score of -8.9 kcal / ml with the target and had 17 anti-correlating residues in Pocket 1 after molecular dynamics simulation. The complex formed by Isopteropodin and the target had a total RMSD of 4.408 and a total RMSF of 9.8067. However, Strophanthidin formed 3 hydrogen bonds with the target at ILE21, GLY262 and LEU294, and induced a total RMSF of 5.4541 at Pocket 1. Conclusion: Overall, Isopteropodin and Strophanthidin were found to be better drug candidates than OOU and they showed potentials to inhibit the Brucella melitensis Methionyl-tRNA synthetase at Pocket 1, hence abilities to treat brucellosis. In-vivo and in-vitro investigations are needed to further evaluate the efficacy and toxicity of the lead compounds.

Zoonotic Campylobacter species (ZCS), particularly C. jejuni and C. coli, cause major foodborne gastroenteritis and poultry is the principal reservoirs. However, there is limited data on Campylobacter transmission risk practices and antimicrobial resistance (AMR) in Nigeria. Therefore, this study determined the prevalence, AMR, and risk practices aiding Campylobacter transmission in two major slaughterhouses processing poultry carcasses in Enugu State, Nigeria. Four hundred poultry faecal samples were analysed for zoonotic Campylobacter organisms using standard protocols. Antimicrobial resistance was profiled via Kirby–Bauer disk diffusion technique, against eight antimicrobial agents. Risk practices were assessed through slaughterhouse observations and interviews with 56 workers. The overall prevalence of Campylobacter infections was 14.5% (58/400), while the species-specific prevalence were 13% (52/400) and 1.5% (6/400) for C. coli and C. jejuni, respectively. Campylobacter colonisation was significantly higher (p < 0.05) in broilers, and during the wet season. The AMR profile of the isolates against the eight antibiotics tested was: Amoxicillin/clauvlanic acid (100%), vancomycin (100%), tetracycline (96.6%), ciprofloxacin (55.2%), chloramphenicol (44.8%), ceftazidime (10.3%), azithromycin (3.4%) and streptomycin (3.4%). All the 58 Campylobacter isolates were multidrug-resistant. The multiple antibiotic resistance indices ranged from 0.4 to 0.9, with a mean of 0.7. Major risk practice associated with ZCS transmission include non-use of personal protective equipment (100%), slaughtering on unsanitary surfaces (100%), using visibly unclean water for meat processing (100%), improper manual evisceration (75%), eating or drinking during processing (64.4%), slaughtering sick animals (37.5%), inadequate cleaning of surfaces and equipment after use (21.4%) and consuming raw meat during carcass processing (19.6%). The findings reflect critical gaps in food safety, occupational health, prudent antimicrobial use in poultry farming and zoonotic disease control, emphasizing the need for antibiotic regulation, training on hygienic meat processing, public education, infrastructural development of slaughterhouse facilities, and inter-sectorial collaboration to curb Campylobacter contamination and spread of antimicrobial resistance.

Background and Aim: Contamination of meat with Salmonella could result in food-borne disease outbreaks among the consumers. However, there is a dearth of data assessing the presence of Salmonella in beef in Anambra State. Therefore, this study determined the prevalence and antimicrobial susceptibility of Salmonella in beef and slaughter/processing facilities in Kwata slaughterhouse. Materials and Methods: Swab samples (200) randomly collected were cultured for the isolation of Salmonella and the isolates subjected to antimicrobial susceptibility test. Data obtained were analyzed using t-test and analysis of variance with p< 0.05 considered statistically significant. Results: Of the 200 samples cultured, 33.5% (67/200) yielded Salmonella isolates. The mean Salmonella load (colony-forming unit [CFU]/cm2) for different contact surfaces (before and after contact with carcasses) was as follows: Slaughter floor, 1.1×1010±1.1×106a and 1.0×1010±1.1×106b; display table, 1.1×1010±11.1×106a and 1.0×1010±1.1×106b; washing bucket 1.01×1010±1.0×106a and 0.8×1010±0.1×106b; knife, 1.1×1010±1.10×106a and 1×1010±1.0×106b; boot, 1.1×1010±1.0×106a and 1.0×1010±1.10×106b; file, 1.1×1010±1.0×106a and 1.0×1010±0.1×106b; and wheelbarrow, 1.1×1010±1.0×106a and 1.01×1010±0.11×106b. Salmonella counts decreased significantly (p<0.05) in the presented order from slaughter floor to wheelbarrow after contact with carcasses. On the other hand, there was a significant (p<0.05) increase in washing water Salmonella counts before and after (0.7×1010±0.10×106a and 1.0×1010±1.0×106b CFU/100 ml) carcasses wash. To each of the antimicrobials tested, the percentage of the 67 isolates found resistant was as follows: ciprofloxacin, 25.4%; ofloxacin, 27%; ceftriaxone, 35.8%; amoxicillin/clavulanic acid, 88.1%; chloramphenicol, 59.7%; gentamicin, 34.3%; streptomycin, 49.3%; nalidixic acid, 49.3%; trimethoprim/sulfamethoxazole, 76%; nitrofurantoin, 89.6%; and ampicillin, 100%. Conclusion: Antimicrobial-resistant Salmonella were isolated from beef and slaughter/processing facilities in Anambra State. This underscores the need for a coordinated one health approach for the improvement of hygienic standard during slaughter/processing in the slaughterhouse surveyed, to limit meat contamination and hence safeguard human health.

Background: Staphylococcus aureus is a major zoonotic and foodborne pathogen with substantial One Health implications, yet its prevalence, resistance, and virulence potential within the aquaculture sector in Nigeria remains poorly characterized. Objectives: To supplement existing information, this current study investigated the prevalence, clonal distribution, antimicrobial resistance, and virulence gene profiles of S. aureus isolates from fish, fish water, and occupationally exposed fish handlers in Anambra State, Southeast Nigeria. Methods: A total of 607 samples—comprising 465 surface swabs from raw and processed fish, 36 fish water samples, and 106 nasal swabs from fish handlers—were processed using selective culture, biochemical tests, antimicrobial susceptibility testing, DNA microarray analysis, spa typing, and SCCmec typing. Results: S. aureus was recovered from 16.5% (100/607) of the samples. Fourteen (14%) isolates were methicillin-resistant (MRSA), harboring mecA and SCCmec types IV and V, with a combined MRSA prevalence of 2.3%. Multidrug resistance was observed in 52.2% of isolates (mean Multiple Antimicrobial Resistance index: 0.23), with 19 resistance genes spanning nine antimicrobial classes—including heavy metal and biocide resistance. Twenty-eight spa types across 13 clonal complexes (CCs) were identified, with CC1, CC5, and CC8 predominating. The detection of shared spa types between fish and handlers indicates potential cross-contamination. Detected virulence genes included those for accessory gene regulators (agrI-IV), Pantone–Valentine leucocidin (lukFS-PV), toxic shock syndrome (tsst-1), hemolysins (hla, hlb, hld/hlIII, hlgA), biofilm formation (icaA, icaD), immune evasion (chp, scn, sak), enterotoxins (sea, seb, sec, sed, egc, and others), exfoliative toxins (etA, etB), epidermal cells differentiation (edinA, edinB), and capsular types (cap5, cap8). Conclusions: This study reveals that the aquaculture sector in Southeast Nigeria serves as a significant reservoir of genetically diverse, multidrug-resistant S. aureus strains with robust virulence profiles. These findings highlight the necessity of integrated One Health surveillance and targeted interventions addressing antimicrobial use and hygiene practices within aquatic food systems.