Veterinary Research Forum

Abstract American foulbrood (AFB) and European foulbrood (EFB) diseases caused by Paenibacillus larvae and Meliscococcus plutonius are prevalent honeybee brood diseases that pose significant economic challenges to the apiculture industry globally. Antibiotic treatment has led to the emergence of antibiotic-resistant strains, encouraging the search for alternative and safe measures to effectively control these diseases. Honeybee gut microbiomes have proven effects on all spectra of honeybee health by enhancing resistance to several diseases via immune modulation and the production of different antimicrobial metabolites. The major part of the gut microbiota is identified as probiotic bacteria, which are live microorganisms that, when administered in adequate amounts, confer health benefits to the host. Probiotics have shown promising health benefits for honeybees. Honeybee gut probiotics provide protection via the production of different metabolites (postbiotics), such as hydrogen peroxide, vitamins, organic acids, free fatty acids, bacteriocins, neurotransmitters, secreted bio-surfactants, and reactive oxygen species. Vast numbers of these gut bacteria and their postbiotics have wide-spectrum antibacterial effects on AFB and EFB. This review highlights the significance of the honeybee gut microbial community, its probiotic potency, and the role of postbiotic metabolites as safe prophylactic measures for preventing AFB and EFB diseases in honeybees.

Abstract In recent years, the use of probiotics and their metabolites, known as postbiotics as natural preservatives has received increasing attention in the food industry. This study aimed to prepare and characterize postbiotics of Lactiplantibacillus sakei and to investigate its application as an anti-Listeria solution on beef fillets using an aerosolization technique. The functional groups, including organic acids, polysaccharides and other minor metabolites, were identified by Fourier transform infrared (FTIR) in the postbiotics. The 2, 2′-diphenyl-1-picrylhydrazyl radical scavenging activity of the postbiotics was reported as 0.82 mg mL^-1. The antimicrobial test using the agar well diffusion method revealed a zone of inhibition of 27.00 ± 1.20 mm. Application of an aerosolized postbiotics solution resulted in a significant reduction in Listeria monocytogenes counts on beef fillets, reaching 3.30 log₁₀ CFU g^-1 over a 15-day storage period at 4.00 ± 1.00 ˚C. The results of this study revealed that the postbiotics of L. sakei was an effective antimicrobial additive for controlling foodborne pathogens in beef fillets and aerosolization is a promising method for developing an antimicrobial coating on meat to enhance meat safety.

Abstract The purpose of this review was to assess the use of plant essential oils and extracts (PEOE) in the development of antimicrobial edible films for dairy application through a systematic review and meta-analysis. All studies published in multiple databases were explored via PRISMA protocol on November 1, 2022. According to the results, the interquartile range of pathogen reduction potential of essential oil (EO) in dairy products, irrespective of EO, film and product type, was 0.10 - 4.70 log CFU g^-1 per % concentration. The findings from 38 articles indicate that among all EOs or their compounds, Zataria multiflora Boiss in protein film, thyme in protein film, Z. multiflora Boiss EO in protein film, Trans-cinnamaldehyde in carbohydrate film and lemongrass EO in protein film had extraordinary pathogen reduction potential on important foodborne pathogens. In the case of plant extract, fish gelatin film with Lepidium sativum extract, whey protein isolate film loaded with oregano EO and carboxymethyl cellulose film with clove EOs had the highest antimicrobial effect on mesophilic bacteria (9.50 log CFU g^-1 per % concentration), yeast-mold (2.63 log CFU g^-1 per % concentration) and mesophilic/ psychrophilic counts (> 9.06 log CFU g^-1 per % concentration), respectively. Listeria monocytogenes is the primary species of interest; whereas, mesophiles and mold-yeast populations were the most investigated microbiota/mycobiota in cheese with PEOE-incorporated film. In light of these findings, the choice of PEOE at appropriate concentrations with the selection of appropriate edible film may improve the safety, sensory, and shelf life of dairy products.