The aim of this study was to determine changes of reactive oxygen species (ROS), serum antioxidant capacity (SAC), oxidative stress index (OSi), and α-tocopherol (α-T) during the periparturient period in healthy and mastitic cows and to further investigate whether these parameters can be used as a tool for identifying cows at higher risk of developing mastitis. Blood samples from 110 dairy cows from two commercial farms were obtained at dry-off, calving, and 30 days post-partum. Healthy cows formed group A (n = 90) and mastitic cows B (n = 20). Blood serum was obtained by centrifugation, and the aforementioned parameters were determined. A general linear model was used for analysing the associations among the determined blood parameters, the health of the animals’ udder, and the sampling time. ROS and OSi values were higher (P < 0.001) by a respective 14% and 26%, and SAC values lower (P < 0.001) by 10% in group B than in group A at calving. ROC curve analysis revealed that all determined parameters at calving and α-T at dry-off and 30 days post-partum had excellent or acceptable predicting ability for mastitis incidence. This information provides a tool for early identification of cows at high risk of developing mastitis, allowing the implementation of intervention strategies.

Silage quality deteriorates with Clostridium spp. contamination, and if consumed, such silage jeopardises herd health and productivity. Minimising its occurrence reduces economic and animal welfare risks. The study investigated the influence of environmental and technological determinants on the Clostridium genus’ occurrence in silage. Analyses were conducted on 305 silage samples directly collected from farms located in all Polish provinces. Cultures and isolates were evaluated phenotypically and examined for occurrence of Clostridium spp., particularly C. perfringens and C. botulinum using PCR techniques. The results were statistically analysed using the ᵡ² test for continuous and Student’s t-test for non-continuous values. The most influential effect on Clostridium spp. occurrence is exerted by factors potentially associated with primary production, like the type of fertilisation and the contamination level of the ensiled feed material. Clostridium spp. was detected in 232 (76%) samples, and C. perfringens strains, predominantly toxinotype A, in 79 (26%). C. botulinum occurrence was not detected. Deterioration of silage by clostridia could be prevented by a properly conducted ensiling process with the addition of starter cultures, but the presence of spores mainly depends on primary production and the extent of contamination of the feed material.

This paper reports polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), and polychlorinated biphenyl (PCB) concentrations in fish collected from Polish and Vietnamese farms and the related risk for consumers. Altogether, 160 samples were analysed using an isotope dilution technique with high-resolution gas chromatography coupled with high-resolution mass spectrometry (HRGC-HRMS). To characterise the potential health risk associated with PCDD/F and dioxin-like polychlorinated biphenyl (DL-PCB) intake, doses ingested in two 100 g portions of fish by adults and children were calculated and expressed as the percentage of the tolerable weekly intake (TWI) newly established by the EFSA in November 2018 at 2 pg WHO-TEQ kg⁻¹ b.w. Generally, levels in fish muscles were low in relation to maximum limits (4), being in the range of 0.02–3.98 pg WHO-TEQ g⁻¹ wet weight (w.w.) for PCDD/F/DL-PCBs and 0.05–24.94 ng g⁻¹ w.w. for NDL-PCBs. The highest concentration was found in eel muscles. The least polluted were pangas and zanders and the levels were at the limits of quantification. Consumption of two portions of fish per week results in intakes of 9– 866% TWI by children and 4–286% TWI by adults. Frequent consumption of some species (for example eel and bream) can pose a health risk to vulnerable consumers and especially children and pregnant women.

Repeated incursions of highly pathogenic avian influenza virus (HPAIV) H5 subtype of Gs/GD lineage pose a serious threat to poultry worldwide. We provide a detailed analysis of the spatio-temporal spread and genetic characteristics of HPAIV Gs/GD H5N8 from the 2019/20 epidemic in Poland. Samples from poultry and free-living birds were tested by real-time RT-PCR. Whole genome sequences from 24 (out of 35) outbreaks were generated and genetic relatedness was established. The clinical status of birds and possible pathways of spread were analysed based on the information provided by veterinary inspections combined with the results of phylogenetic studies. Between 31 December 2019 and 31 March 2020, 35 outbreaks in commercial and backyard poultry holdings and 1 case in a wild bird were confirmed in nine provinces of Poland. Most of the outbreaks were detected in meat turkeys and ducks. All characterised viruses were closely related and belonged to a previously unrecognised genotype of HPAIV H5N8 clade 2.3.4.4b. Wild birds and human activity were identified as the major modes of HPAIV spread. The unprecedentedly late introduction of the HPAI virus urges for re-evaluation of current risk assessments. Continuous vigilance, strengthening biosecurity and intensifying surveillance in wild birds are needed to better manage the risk of HPAI occurrence in the future.

Contamination by Staphylococcus aureus of food produced from animal sources may have diverse and multifactorial causes that depend on geographical distribution. The goal of this study was to isolate and characterise S. aureus strains from contaminated fermented pork sausage, which is a local food of northeastern Thailand. S. aureus strains were isolated from local pork sausage, and the presence of classical enterotoxins was determined by PCR and reversed passive latex agglutination. These results were compared with strains derived from hospitalised patients and healthy carriers. Additionally, production of extracellular enzymes and haemolysin, biofilm formation, and antibiotic susceptibility were assessed. S. aureus was identified in 36 sausage isolates (60%). The strains positive for staphylococcal enterotoxin A were more frequently found in isolates from sausage and healthy carriers than in those from patients. All tested S. aureus strains were positive for DNase, lipase, proteinase, haemolysin, and biofilm formation; notably, strains isolated from food and healthy carriers displayed similar values. Most isolates were resistant to penicillin and ampicillin, while none were to methicillin. Thai fermented pork sausages are associated with a high risk of staphylococcal food poisoning, which may be linked to contamination caused by carriers. Dissemination of knowledge regarding best practices in sanitation and hygiene is important in local communities.

Salmonellosis is a zoonotic disease, and Salmonella spp. can sometimes be found in dogs and cats, posing a risk to human health. In this study, the prevalence and antimicrobial susceptibility of faecal Salmonella were investigated in pet dogs and cats in Xuzhou, Jiangsu Province, China. Faecal samples from 243 dogs and 113 cats, at seven pet clinics, were tested between March 2018 and May 2019. Each Salmonella isolate was characterised using serotyping and antimicrobial susceptibility tests. The prevalence of Salmonella was 9.47% in dogs and 1.77% in cats. Among the 25 isolates, eight serotypes of Salmonella enterica subsp. enterica were detected, S. Kentucky (n = 11), S. Indiana (n = 5), and S. Typhimurium (n = 4) predominating. S. Derby, S. Toucra, S. Sandiego, S. Newport, and S. Saintpaul all occurred singly. The 23 Salmonella strains found in dogs were from seven different serovars, while the two strains in cats were from two. The highest resistance rates were found for tetracycline (92%), azithromycin (88%), cefazolin (84%), nalidixic acid (80%), ampicillin (80%), ceftriaxone (80%), and streptomycin (76%). Resistance to three or more antimicrobial agents was detected in 24 (96%) isolates. Most of the S. Kentucky and S. Indiana isolates were multi-drug resistant to more than 11 agents. The carriage rate was far higher in dogs than in cats from Xuzhou. Some isolated strains were highly resistant to antimicrobials used to treat infections in humans and pets, which may raise the risk of humans being infected with multi-drug resistant Salmonella via close contact with pets.