Journal of Veterinary Research最新文献

Introduction: Listeria monocytogenes is an important foodborne pathogen responsible for human listeriosis, which is a disease with high hospitalisation and mortality rates. The bacteria are usually susceptible to most antibacterial substances, but resistance to some of them has been recently observed. The present study introduces the evidence on the emergence of antibiotic resistance among L. monocytogenes strains isolated from food and food-production environments in Poland.

Material and methods: A total of 283 L. monocytogenes isolates classified into serogroups IIa and IVb which had been recovered from food and food production environments were tested with 17 antimicrobials. These included those that are recommended for treatment of severe listeriosis cases in humans. A multiplex PCR was used to identify serogroups, and a microbroth dilution method was applied for the determination of antibiotic resistance among the isolates tested.

Results: Only 34 (12.0%) strains were susceptible to all the antimicrobials used in the study. The remaining 249 (88.0%) strains displayed different instances of resistance to the antimicrobials tested, from insusceptibility to one (112 strains; 39.6%) to resistance to four antibacterial substances (6 strains; 2.1%). Among them, there were 38 strains (13.4%) with multiresistance patterns.

Conclusion: Polish food and its processing environments may be a potential source of antimicrobial-resistant L. monocytogenes, which may pose a potential health risk to consumers in the country.

Introduction: Radioactive contamination of the environment is one of the greatest threats after a nuclear accident due to released radionuclides. From a radiotoxicological point of view, the most important radionuclide is caesium-137. Formed mainly during nuclear explosions, caesium-137 can persist in the soil for many years, from where it constantly enters the food chain. One of the elements of ensuring food safety is the monitoring of its radioactive contamination, mainly with radioactive caesium isotopes. The aim of the study was to determine the content of caesium-137 in food of animal origin.

Material and methods: A total of 1,416 muscle samples from cattle, sheep, pigs, game and fish, as well as chicken eggs and dairy products were examined using gamma-ray spectrometry.

Results: Caesium-137 activities ranged from below the minimum detectable activity concentration (MDC) to over 4,000 Bq/kg wet weight (w.w.). Most often, the values did not exceed the MDC or were in a range below 100 Bq/kg. The exception was the muscle tissue of game animals, especially wild boar, where a significant activity of caesium-137 was recorded, the highest of which was 4,136.8 ± 238 Bq/kg w.w. Committed effective doses determined for each matrix ranged from 0.01 to 0.83 µSv/kg, with the highest value determined for wild boar.

Conclusion: The calculated exposure doses with values well below the accepted low radiation dose (100 mSv) did not indicate any significant amounts of ionising radiation from the food consumed.

Introduction: Universally, in microbiological diagnostics the detection of live bacteria is essential. Rapid identification of pathogens enables appropriate remedial measures to be taken. The identification of many bacteria simultaneously facilitates the determination of the characteristics of the accompanying microbiota and/or the microbiological complexity of a given environment.

Material and methods: The effectiveness of the VITEK2 Compact automated microbial identification system and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS), analytical profile index (API) and Remel RapID tests were compared in identification of bacteria isolated from the alpaca gastrointestinal tract.

Results: Most isolates were Gram-positive, such as Bacillus cereus, Bacillus flexus, Bacillus licheniformis, Bacillus pumilus and Bacillus subtilis; Enterococcus faecium, Enterococcus gallinarum, Enterococcus hirae and Enterococcus casseliflavus; Staphylococcus aureus, Staphylococcus equorum, Staphylococcus lentus, Staphylococcus pseudintermedius and Staphylococcus sciuri; Paenibacillus amylolyticus; Cellulosimicrobium cellulans; Leuconostoc mesenteroides; Clostridium perfringens; Corynebacterium stationis, Corynebacterium xerosis, and Corynebacterium diphtheriae (the last only isolated manually by API Coryne and the VITEK2 system and Corynebacteria (CBC) card). Corynebacterium diphtheriae was misidentified by MALDI-TOF MS as Candida lipolytica (currently Yarrowia lipolytica). Gram-positive and Gram-variable Micrococcus luteus were also isolated. Gram-negative Enterobacter cloacae, Enterobacter gergoviae, Enterobacter hormaechei and Enterobacter ludwigii; E. coli; Klebsiella pneumoniae subsp. pneumoniae; Citrobacter braakii and Citrobacter freundii; Serratia liquefaciens, Serratia odorifera and Serratia marcescens; Morganella morganii subsp. morganii; Providencia alcalifaciens; Pseudomonas aeruginosa; Stenotrophomonas maltophilia; Moraxella osloensis; and Ochrobactrum intermedium were also found. The yeasts Candida albicans, Candida haemulonii and Candida ciferrii were also present.

Conclusion: MALDI-TOF MS enabled the identification of pathogens and opportunistic pathogens from the alpaca gut which may represent a high risk to human and animal health.

Introduction: The aim of the study was to compile data on the frequency and distribution of canine skin tumours and determine the risk of these being malignant as opposed to benign. This determination proceeded from tumour histogenesis and gave consideration to the dog's breed, sex, age and the anatomical location of tumours.

Material and methods: This retrospective five-year epidemiological study included 3,139 canine skin tumours collected in Poland. A univariable logistic regression analysis was performed to determine the odds ratios (ORs) with 95% confidence intervals (CIs).

Results: Microscopic analysis showed a significant predominance of benign tumours (65.02%) as well as mesenchymal and melanocytic tumours (59.57%). The most frequently diagnosed were mast cell tumours, accounting for 13.79% of all skin tumours, and other common tumour types were lipomas (6.40%), haemangiopericytomas (5.96%) and malignant melanomas (4.65%). The risk of malignant versus benign tumours was 1.212 times higher in the female than in the male dogs. A higher risk of development of malignant epithelial tumours was found in boxers (OR 4.091), German shepherds (OR 4.085) and flat-coated retrievers (OR 43.596). A higher risk of development of malignant mesenchymal tumours was found in golden retrievers (OR 4.693), boxers (OR 2.342), bulldogs (OR 3.469) and Maltese (OR 2.757).

Conclusion: The results may serve as a reference point for further studies of the complex biology of canine skin tumours.

Introduction: The purpose of this study was to perform a morphometric examination of the coronary ostia, including their location in the area of the aortic sinuses, and to describe variations in ostia structure in the domestic dog.

Material and methods: The study was conducted on the hearts of 91 pedigree dogs of both sexes, aged 1 to 18 years (median 9 years), with a body weight from 1.2 to 65 kg (median 20.7 kg). Morphometric examinations of the coronary ostia were performed in the studied individuals, and the location of the structures in relation to the intercommissural lines was determined.

Results: Three types of location of the coronary ostia were distinguished, i.e. below the intercommissural line (type I), on the intercommissural line (type II), and above the intercommissural line (type III). In the studied dogs, the most common location of the ostia was type I - found in the left coronary artery of 74/91 dogs (81%) and in the right coronary artery of 42/91 dogs (46%). Morphological variations were shown in 36/91 dogs (40%) in the structure of the coronary ostia, including the presence of accessory ostia. The most common variation was the presence of an accessory ostium near the ostium of the right coronary artery, which was found in 28/91 dogs (31%).

Conclusion: The results may be useful in developing standards for procedures to replace the whole or part of the aortic valve and repair the coronary artery.

Introduction: New and more effective therapies for canine cancer patients are urgently required and this necessitates advanced experimental research. Dogs are good models for studies in comparative oncology; however, canine cancer cell biology research is currently limited by low availability of validated antibody reagents and techniques. This study characterises the expression of key components of the unfolded protein response (UPR) in a panel of haematopoietic canine cancer cell lines using commercially available antibodies, and validates the methods used to study this pathway.

Material and methods: The CLBL-1 canine lymphoma cell line and the GL-1 canine leukaemia cell line sourced externally and two counterparts established in house (CNK-89 and CLB70) were used as models of different lymphoma and leukaemia canine cell lines for the study. The human U2OS cell line served as the control. Antibodies were selected for identifying UPR proteins according to known canine cell reactivity and canine-murine and canine-human homology. Endoplasmic reticulum stress was induced with thapsigargin and MG132 in the cell lines. Etoposide was used to induce DNA damage in the cells. The techniques used for this validation analysis were RNA sequencing to observe the expression of UPR components in canine cell lines, Western blot to observe changes of protein expression levels after inducing ER stress in the cells, and flow cytometry in order to study cell death.

Results: Substantial variations in both the basic expression and agonist-induced activation of the UPR pathway were observed in canine cancer cell lines, although the biological significance of these differences requires further investigation.

Conclusion: These findings will be a starting point for future studies on cancer biology in dogs. They will also contribute to developing novel anticancer therapies for canine patients and may provide new insights into human oncology.

Introduction: Penconazole (PEN) is a widely applied triazole fungicide. This study sought to define the efficacy of N-acetyl-l-cysteine (NAC) in mitigating PEN-triggered hepatorenal toxicity in rats.

Material and methods: Twenty-eight adult male albino Wistar rats were assigned to four groups: a normal control (NC), a PEN group, a NAC group and a PEN+NAC group. Administration of PEN (50 mg/kg body weight (b.w.) every 2 days) and NAC (150 mg/kg b.w., daily) took place via oral gavage for 10 days.

Results: Effective amelioration by NAC of PEN-induced liver and kidney dysfunction was indicated by a significant reduction in the circulating liver and kidney markers (aspartate aminotransferase, alanine aminotransferase, urea and creatinine). Attenuation of PEN-induced oxidative stress and lipid peroxidation in liver and kidney tissues was evident in a significant reduction in malondialdehyde and enhanced total antioxidant capacity. Moreover, NAC significantly reduced the histopathological alterations and the expression of tumour necrosis factor α in liver and kidney tissue. Furthermore, NAC maintained the messenger RNA levels of nuclear factor erythroid 2-related factor 2 (Nrf2), haem oxygenase 1, and Kelch-like erythroid cell-derived protein 1 and prevented nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) protein upregulation caused by PEN.

Conclusion: N-acetyl-1-cysteine protected against PEN-induced hepatorenal oxidative damage and inflammatory response via activation of Nrf2 and inhibition of NF-κB pathways.

Introduction: The disease caused by carp edema virus (CEV) manifests with lethargy as a primary sign; this observation in koi in Japan gained the disease the name koi sleepy disease (KSD). In the years following the discovery of the virus in Japan, KSD cases have been noted in the UK in koi and common carp. Conducting research in order to expand knowledge of the processes of distribution of CEV in infected fish organs will be helpful for eradication and diagnostic purposes.

Material and methods: Carp edema virus-affected fish with clinical signs of KSD were experimentally cohabited with common carp fry (30 fish). Three fish were euthanised by bath in a 0.5 g L^-1 tricaine solution at one week intervals (7, 14, 21 and 28 days post cohabitation). Tissue samples from the brain, gills, spleen, kidney, intestines and skin were collected, and the total DNA was extracted and tested by real-time PCR.

Results: By the seventh day post infection, CEV DNA was most often found in the skin, gills and brain and less frequently in the kidney and intestines. In many of the common carp fry, CEV DNA could typically be found in several organs of each individual fish, although it was only found in one sample of spleen tissue.

Conclusion: In this experimental study the pathogenesis of the CEV infection process was shown, the high infectivity of CEV was confirmed and the best organs were determined for sampling in CEV-infection experimentation. The real-time PCR method used in our cohabitation experiments was shown to be useful at the clinical and asymptomatic stage of virus infection.