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: Newcastle disease (ND) is widely recognized as an extremely harmful and contagious disease of birds. Therefore, the present study aims to evaluate the effect of oxidative stress induced by the virulent ND virus (NDV) (KUDU 113) on the plasma, brain, bursa of Fabricius, NDV antibody response, and hematology as well as the ameliorative effect of the individual or combined use of Vitamins E and C on the clinical signs of NDV-infected chickens. Materials and Methods: In this study, a total of 150 broiler chickens were included and divided into five groups: Group 1, nonsupplemented and unchallenged chickens (UCC); Group 2, nonsupplemented and challenged chickens (ICC); Group 3, Vitamin C-supplemented + challenged chickens; Group 4, Vitamin E-supplemented + challenged chickens; and Group 5, Vitamins E and C-supplemented + challenged chickens. Groups 3, 4, and 5 were supplemented with Vitamins E and C (33 and 400 mg/kg/day, respectively). Virus challenge was done with 0.1 ml of KUDU 113 7 days after the start of vitamin inclusion in their diet. Concentrations of glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT) were analyzed in the plasma, brain, and bursa on days 0, 3, and 7 post-infection (pi) using the biochemical method. The blood samples were randomly collected from five chickens in each group for antibody response and hematological analyses on day 0 previtamin treatment and at 0, 3, 7, 10, 14, and 21 days pi (dpi). Results: A significant increase in the concentrations of MDA and NO in the NDV-challenged chickens was observed when compared with the UCCs. Moreover, a significant decrease in GSH concentration was observed in the NDV-challenged chickens when compared with the UCCs. The activities of CAT and SOD were reduced markedly in the NDV-challenged chickens. Increases in the mean antibody titers were observed in the NDV-challenged group when compared with the UCCs from days 3 to 21 pi. The mortality rates of groups 1, 2, 3, 4, and 5 were 0%, 30%, 3.3%, 3.3%, and 26.6%, respectively. Conclusion: The findings of this study suggest that KUDU 113 causes oxidative stress in the brain and bursa of Fabricius of chickens. Individual supplementation with Vitamin E or C was found to be more effective in ameliorating oxidative stress, improving the immune response, and reducing mortality in KUDU 113 infections than the combined supplementation of Vitamins C and E.

Background and Aim: Campylobacter jejuni and Campylobacter coli are leading causes of bacterial foodborne gastroenteritis worldwide, with poultry serving as a principal reservoir. The rapid emergence of antimicrobial-resistant (AMR) Campylobacter strains poses a growing public-health challenge, especially in developing countries where therapeutic options are limited. This study investigated the fecal carriage and AMR profiles of zoonotic Campylobacter species (ZCS) isolated from broilers. Materials and Methods: A cross-sectional study was conducted between February and July 2024. A total of 370 broiler fecal samples were collected using systematic random sampling and cultured on Modified Charcoal Cefoperazone Deoxycholate Agar. Phenotypic identification was performed by colony morphology, Gram staining, and biochemical tests. Antimicrobial susceptibility was assessed using the Kirby–Bauer disk diffusion method against nine antibiotics from distinct classes. Multiple antibiotic resistance (MAR) indices were calculated, and Fisher’s exact test was applied to determine statistical associations (p < 0.05). Results: Campylobacter spp. were detected in 20% (74/370) of samples, comprising C. jejuni 6% (22/370) and C. coli 14% (52/370). Nearly all isolates (97.3%) exhibited multidrug resistance (MDR), with MAR indices ranging from 0.2 to 1.0 (mean = 0.8). Thirteen distinct AMR patterns were observed; seven were associated with C. coli and six with C. jejuni. The three most effective antibiotics were gentamicin (GEN) > ciprofloxacin > tetracycline (TET), though C. coli isolates were significantly more resistant to GEN (p = 0.001) and TET (p = 0.018). Conclusion: The 20% fecal carriage of ZCS in slaughtered broilers and the 97.3% MDR prevalence pose a serious public-health and food-safety threat. Prudent antimicrobial use strengthened farm biosecurity, and active AMR surveillance under a One Health framework are urgently needed to curb the spread of antibiotic-resistant Campylobacter spp. in poultry production systems and to safeguard human health. Keywords: antimicrobial resistance, broilers, Campylobacter coli, Campylobacter jejuni, food safety, multidrug resistance, One Health.

Non-typhoidal Salmonella (NTS) is an important poultry-associated pathogen with major One Health and economic impacts, but data on its epidemiology and antimicrobial resistance in Nigeria remain limited. This study investigated the prevalence, serovar distribution, clonal relatedness, and antimicrobial resistance of NTS along the poultry production chain in Enugu State, southeastern Nigeria. A total of 2400 samples were collected, comprising feces (cecal content)/cloacal swabs from chickens (n = 1100), eggs (n = 400), chicken meat (n = 600), and stool samples from poultry workers (n = 300). Isolation and identification were performed using standard bacteriological methods, with confirmation by serotyping and polymerase chain reaction (PCR) targeting the invA gene. Genetic relatedness was assessed using enterobacterial repetitive intergenic consensus (ERIC)-PCR, and antimicrobial susceptibility was determined by the disk diffusion method. Overall, 47 (2.0%) Salmonella enterica isolates were recovered from 2400 samples, with the highest prevalence observed in eggs (3.5%), followed by human stool (3.3%), chicken meat (1.8%), and chicken feces (1.1%). Only 35 (11.8%) of the 297 sampled farms were positive for Salmonella, and recovery rates differed significantly (p = 0.0065) among sample sources. Five serotypes were identified, dominated by S. Typhimurium (57.4%), followed by S. Enteritidis (14.9%), S. Anatum (12.8%), S. Stanley (8.5%), and S. Agona (6.3%). ERIC-PCR revealed multiple clonal clusters, many containing isolates from mixed sources, indicating circulation of related strains between poultry and humans. All isolates were resistant to ampicillin, with high resistance to tetracycline (76.6%), sulphamethoxazole–trimethoprim (51.1%), and fluoroquinolones. Overall, 80.9% of isolates were multidrug-resistant, with a mean Multiple Antibiotic Resistance Index of 0.29, highest among isolates from chicken feces. Although the prevalence of NTS was low, the presence of genetically related multidrug-resistant strains across the production chain underscores the role of poultry as a reservoir for zoonotic transmission and highlights the need for coordinated One Health surveillance and antimicrobial stewardship strategies in Nigeria.

Background: Frequent use of colistin (COL) and tetracyclines in the Nigerian poultry sector potentially triggers bacterial resistance against COL and tigecycline (TIG), which are last-line antibiotics used to treat multidrug-resistant infections. Aim/Objectives: This study aimed to isolate COL- and TIG-resistant E. coli from commercial day-old chicks distributed to poultry farmers in Nsukka Southeastern Nigeria, assess the production of extended-spectrum β-lactamase (ESBL) and carbapenemase by the isolates, and establish their pathogenic potentials. Materials and Methods: Non-duplicate cloacal swabs were systematically collected from 250 randomly selected day-old chicks. MacConkey agar with 1 µg/mL of COL and 16 µg/mL of tetracycline was used for the isolation of putative COL- and tetracycline-resistant E. coli, respectively. E. coli isolates were confirmed biochemically using the API20E Gram-negative identification kit and molecularly by polymerase chain reaction targeting the uidA gene. Phenotypic COL resistance was established using COL agar and COL disc elution tests, while TIG insusceptibility was determined with disc diffusion. ESBL and carbapenemase production was assessed by double-disc synergy and modified carbapenem inactivation methods, respectively. Pathogenic potentials were determined using phenotypic methods. Results: COL- and TIG-resistant E. coli was recovered from 95 (38.0%) and 62 (24.8%) swabs from the 250 chicks, respectively. None of the isolates were potential ESBL or carbapenemase producers. The COL-resistant isolates displayed pathogenic potentials such as biofilm formation, haemagglutination, cell surface hydrophobicity, surface layer, and gelatinase activities at rates of 30.7%, 8.4%, 33.7%, 23.5%, and 17.6%, respectively. Meanwhile, the TIG-resistant isolates exhibited their respective potentials at rates of 47.0%, 21.0%, 35.5%, 58.1%, and 43.6%. Red, dry, and rough (RDAR) was the predominant curli fimbriae, and the cellulose morphotype portrayed by both the COL- and TIG-unsusceptible potential biofilm-producing isolates. Conclusions: This study demonstrates that a significant percentage of commercial day-old chicks distributed to farmers in Nsukka, southeastern Nigeria, are colonized by potentially pathogenic COL- and TIG-resistant E. coli, which could spread to humans and the environment.