Salmonella contamination in poultry meat products can lead to serious foodborne illness and economic loss from product recalls. It is crucial to control Salmonella contamination in poultry from farm to fork. Bacteriophages (phages) are viruses of bacteria that offer several advantages, especially their specificity to target bacteria. In our study, three Salmonella phages (vB_SenS_KP001, vB_SenS_KP005, and vB_SenS_WP110) recovered from a broiler farm and wastewater treatment stations showed high lysis ability ranging from 85.7 to 96.4% on over 56 serovars of Salmonella derived from several sources, including livestock and a broiler farm environment. A three-phage cocktail reduced S. Enteritidis and S. Typhimurium, in vitro by 3.9 ± 0.0 and 3.9 ± 0.2 log units at a multiplicity of infection (MOI) of 10³ and 3.8 ± 0.4 and 4.1 ± 0.2 log units at MOI of 10⁴ after 6 h post-phage treatment. A developed phage cocktail did not cause phage resistance in Salmonella during phage treatments for three passages. Phages could survive under simulated chicken gastrointestinal conditions in the presence of gastric acid for 2 h (100.0 ± 0.0% survivability), bile salt for 1 h (98.1 ± 1.0% survivability), and intestinal fluid for 4 h (100 ± 0.0% survivability). Each phage was in the phage cocktail at a concentration of up to 9.0 log PFU/mL. These did not cause any cytotoxicity to human fibroblast cells or Caco-2 cells as indicated by the percent of cell viability, which remained nearly 100% as compared with the control during 72 h of co-culture. The phage cocktail was given to broilers raised in commercial conditions at a 9 log PFU/dose for five doses, while naturally occurring Salmonella cells colonized in the gastrointestinal tract of broilers were significantly reduced as suggested by a considerably lower Salmonella prevalence from over 70 to 0% prevalence after four days of phage treatment. Our findings suggest that a phage cocktail is an effective biocontrol agent to reduce Salmonella present in the guts of broilers, which can be applied to improve food safety in broiler production.

Tadee P, et al. J Vet Sci. 2023 Dec;25(1):e5. https://doi.org/10.4142/jvs.23189

Mastitis is a major infectious disease that causes significant economic losses in the dairy industry. Current control programs primarily rely on antimicrobials, contributing to the growing concerns of the resistance situation and drug residues in milk. This study aimed to identify the bacterial pathogens responsible for subclinical/clinical bovine mastitis, assess their antimicrobial resistance profiles, and evaluate the antimicrobial effects of Caesalpinia sappan in treating mastitis through both in vitro and in vivo studies. A total of 138 bacterial isolates, representing 40 species, were identified from 100 milk samples collected from dairy cows under the Maejo Cooperative Group in Chiang Mai, Thailand, between May 2021 and February 2022. The most prevalent species was Escherichia coli (10.87%), followed by Bacillus cereus (9.42%) and Staphylococcus sciuri (7.97%). The highest resistance rates were observed for penicillin (65.21%), followed by streptomycin and lincomycin (61.59%). Nine isolates resisted all 18 antimicrobials tested. The average minimum inhibitory concentration (MIC) of C. sappan against the identified pathogens ranged from 0.63 to 17.68 mg/mL, with the highest MIC observed against Pseudomonas luteola. In the animal experiment, treatment with a prototype of an intramammary infusion compound primarily formulated from C. sappan significantly reduced the total bacterial count and California Mastitis Test (CMT) scores (p < 0.01). These results suggest that C. sappan exhibits antimicrobial efficacy against various mastitis bacteria and could serve as a potential alternative treatment to control bovine mastitis in dairy cattle within the study region.

Mastitis is a major infectious disease that causes significant economic losses in the dairy industry. Current control programs primarily rely on antibiotics, contributing to the growing concerns of antibiotic resistance and drug residues in milk. This study aimed to identify the bacterial pathogens responsible for bovine mastitis, assess their antibiotic resistance profiles, and evaluate the antimicrobial effects of Caesalpinia sappan in treating mastitis through both in vitro and in vivo studies. A total of 138 bacterial isolates representing 40 species were identified from 100 milk samples collected from dairy cows raised under the Maejo Cooperative Group, Chiang Mai, Thailand, between May 2021 and February 2022. The most prevalent species was Escherichia coli (10.87%), followed by Bacillus cereus (9.42%) and Staphylococcus sciuri (7.97%). The highest resistance rates were observed for penicillin (63.04%), followed by streptomycin (60.87%) and lincomycin (57.25%). Nine isolates resisted all 18 antibiotics tested. The minimum inhibitory concentration (MIC) of Caesalpinia sappan against the identified pathogens ranged from 0.63 to 17.68 mg/ml, with the highest MIC observed against Pseudomonas luteola. In the animal experiment, treatment with a prototype of intramammary infusion derived from Caesalpinia sappan with and adding Aloe vera significantly reduced the total bacterial count and California Mastitis Test (CMT) scores (p < 0.01). These results suggest that Caesalpinia sappan exhibit antimicrobial efficacy against various mastitis bacteria and could serve as a potential alternative treatment for managing bovine mastitis in dairy cattle within the study region.

Background and Aim: Ectoparasites, such as Menopon gallinae (chicken lice) and Ornithonyssus bursa (chicken mites), have a significant impact on poultry health and productivity, resulting in substantial economic losses and potential zoonotic risks. Conventional synthetic pesticides, though effective, pose health and environmental concerns. Hence, plant-based alternatives such as essential oils are gaining attention for their insecticidal properties. This study aimed to characterize the physical and chemical properties of citronella (Cymbopogon nardus) and ginger (Zingiber officinale) essential oils and to evaluate their acaricidal and insecticidal efficacy, both in vitro and in vivo, against M. gallinae and O. bursa. Materials and Methods: Essential oils were extracted through steam distillation and characterized using specific gravity, refractive index, and optical rotation. Gas chromatography-mass spectrometry (GC-MS) was used to identify major chemical constituents. Contact toxicity assays were conducted on adult lice and mites exposed to essential oil combinations (Citronella [CT]: Ginger [G] in ratios of 70:30, 50:50, and 30:70). In vivo trials were performed on naturally infested chickens and mite-contaminated nests, with efficacy assessed at days 1, 7, and 14 post-treatment. Statistical analyses employed general linear mixed models and Tukey’s post hoc tests. Results: GC-MS revealed citral, neral, and limonene as key constituents of citronella oil, and zingiberene and sesquiphellandrene in ginger oil. All essential oil combinations showed 100% in vitro mortality of lice and mites by 24 h. In vivo, the CT70:G30 formulation achieved the greatest reduction in lice incidence by day 14 (22.67%), followed by trichlorfon (31.33%). For mites, trichlorfon exhibited the highest efficacy (3.33% incidence on day 14), while CT30:G70 also showed notable reduction (40.97%) with no adverse effects observed in treated birds. Conclusion: Combinations of citronella and ginger essential oils, particularly CT30:G70, offer a promising natural alternative to chemical pesticides for managing poultry ectoparasites. Their high efficacy, rapid action, and safety profile support their use in organic and sustainable poultry farming. Keywords: citronella oil, ectoparasite control, essential oils, ginger oil, Menopon gallinae, natural pesticides, Ornithonyssus bursa, poultry health.