Polish journal of veterinary sciences最新文献

The aim of this study was to develop a rapid, sensitive and highly specific TaqMan quantitative real-time polymerase chain reaction PCR (qPCR) assay for porcine circovirus-like virus (PCLV). The primers and probe were designed based on the conserved regions of the PCLV ORF4 gene. The assay has a good detection performance (y=-3.3257x+ 1.482, R2=0.9905), with a limit of detection of 10 copies, which was 100 times more sensitive than conventional PCR (cPCR). No cross-reactivity was observed with other common viruses. The intra- and inter-assay coefficients of variation were less than 1.25%. 36 fecal samples were analyzed using this method, detecting a positivity rate of 8.33% (3/36) that was higher than the cPCR detected. In summary, the established assay for PCLV detection has high specificity, sensitivity, and reproducibility and can be used as a tool for clinical diagnosis and epidemiological investigation.

Streptococcus agalactiae, commonly known as S. agalactiae, is a critical zoonotic pathogen that significantly reduces milk yield and product quality and poses a significant risk to public health. Although S. agalactiae is increasingly recognised as a principal agent causing milkborne infections, research dedicated to this pathogen in dairy cattle has been less extensive than that of other pathogens. This study aimed to examine the antibiotic resistance profiles of S. agalactiae derived from dairy cows and assess its pathogenicity using validated in vivo models. The findings contribute essential scientific insights into the realm of environmental antibiotic resistance research. The resistance of S. agalactiae isolates to drugs was assessed using the broth microdilution technique. Additionally, PCR analysis was used to identify six important virulence genes. The study revealed that S. agalactiae was fully susceptible to streptomycin, meropenem, ciprofloxacin, clindamycin, cefquinome, and cloxacillin in general laboratory settings and within milk samples. However, among the antibiotics tested, tetracycline exhibited the highest level of resistance, with rates reaching 70%. Penicillin showed a resistance level of 50%, followed by doxycycline at 30%. Additionally, the resistance rates for apramycin and cefoxitin were both 20%, whereas florfenicol resistance was observed at a rate of 10%. All isolates of S. agalactiae carried the cfb gene. However, it is noteworthy that only one isolate possessed this gene exclusively, while the other nine isolates shared a uniform set of four additional virulence genes. The study highlighted the significant impact of these virulence factors on the pathogenic behaviour of S. agalactiae from dairy sources. This was demonstrated by the high mortality rates observed in experimental infections using Galleria mellonella (G. mellonella) larvae and mouse models. These findings contribute to understanding the relationship between the pathogenic properties of S. agalactiae and the virulence genes it carries.

Intermediate filaments (IFs) play a major role in determining and maintaining cell shape and anchoring intracellular organelles in place, in the tissues and organs of several species, starting from the early stages of development. This study was aimed at the immunohistochemical investigation of the presence, cellular localization and temporal distribution of the intermediate filaments keratin 8 (CK8), keratin 18 (CK18), keratin 19 (CK19), vimentin, desmin and laminin, all of which contribute to the formation of the cytoskeleton in the rat mammary gland during pregnancy, lactation and involution. On days 7, 14 and 21 of pregnancy (pregnancy period), on day 7 post-delivery (lactation period) and on day 7 post-weaning (involution period), under ketamine hydrochloride (Ketalar-Pfizer) (90 mg/kg) anesthesia, two mammary glands were fully excised from the abdominal region. It was determined that CK8 showed moderate immunoreactions in the alveolar and ductal epithelia, connective tissue and vascular endothelium of the rat mammary gland throughout pregnancy. On the 7th day of pregnancy, CK18 expression was absent in the alveolar and ductal epithelia, but was observed weakly in some connective tissue cells. Throughout pregnancy, lactation and involution, the alveolar and ductal epithelia of the rat mammary gland were determined to be negative for CK19. Desmin expression predominated in the mammary myoepithelium and vasculature throughout all three of the investigated periods. While vimentin was not expressed in any of the mammary tissue components during pregnancy and lactation, its moderate expression was observed in the alveolar and ductal epithelia during involution. The involution period was also characterized by the vimentin negativity of the myoepithelium, stroma, fat cells and blood vessels of the mammary gland. Throughout all three periods, laminin expression was strong in the alveolar and ductal epithelia, stromal and myoepithelial cells and blood vessels, and did not vary in strength between the investigated periods. These findings demonstrated that intermediate filaments showed cell- and tissue-specific expression patterns in the rat mammary gland under the effects of pregnancy, lactation and involution.

Porcine circovirus type 2 (PCV2) is the major causative agent of postweaning multisystemic wasting syndrome which leads to significant economic losses in the global swine industry. In China, there is a widespread dissemination of PCV2 infection in the pig population. Serological diagnosis of the disease is considered as an effective control measure. Here, we developed a capsid protein (Cap)-based enzyme-linked immunosorbent assay (Cap-ELISA) for the detection of PCV2 antibodies in swine serum using a nuclear localization signal-truncated capsid protein produced in Escherichia coli. The Cap protein was expressed as water-soluble and purified using nickel-nitrilotriacetic acid (Ni-NTA) chromatography. After the optimization of the working conditions of the Cap-ELISA using chessboard titrations, a total of 649 serum samples were tested using the Cap-ELISA and a commercial ELISA kit. The diagnostic sensitivity (DSN), diagnostic specificity (DSP) and accuracy of the Cap-ELISA were determined to be 96.7%, 94.1% and 99.5%, respectively. Cross-reactivity analysis indicated that the Cap-ELISA was PCV2-specific and possessed no cross-reactions with antibodies against other common swine pathogens including porcine circovirus type 1 (PCV1), porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), porcine parvovirus (PPV), foot and mouth disease virus (FMDV), porcine epidemic diarrhea virus (PEDV) and pseudorabies virus (PRV). Repeatability of the experiment showed that Cap-ELISA was highly repeatable with the intra- and inter-plate coefficients of variation less than 10%. Hence, the Cap-ELISA has the potential for the swine industry to monitor PCV2 epidemiology and to evaluate PCV2 vaccine efficacy.

The present study aimed to search for the presence of the plasmid-mediated antimicrobial resistance genes in 106 Escherichia coli (E. coli) isolates from a total of 240 fresh fecal samples collected from 12 private cattle farms in Bingol province of East Turkey from November 2021 to January 2022. In those colistin-resistant E. coli (mcr-1 to -9), the major carbapenemase (blaOXA-48, blaNDM-1, blaIMP, blaVIM, and blaKPC), β-lactamase (blaTEM-1, blaCTX-M and blaSHV-1) and OXA-48 like β- lactamase (blaOXA-162, blaOXA-163, blaOXA-181, blaOXA-204 and blaOXA-232) resistance genes were searched for determined a multiplex polymerase chain reaction (PCR) method and Next-generation sequencing (NGS) - PCR Amplicons with Nanopore Technology. Only the mcr-4 gene was found in one isolate and the remaining genes (mcr-1-9) were not shown in all E. coli isolates from cattle. The minimal inhibitory concentration (MIC) to colistin was detected in mcr-4 positive E. coli isolates using broth microdilution. We assessed the antimicrobial susceptibilities of mcr-4 positive E. coli isolates using the Kirby-Bauer disk diffusion method. E coli isolate was detected as negative for carbapenemase and OXA-48 like β-lactamase resistance genes and positive for β-lactamase. In addition, E. coli isolates carrying mcr-4 were more resistant to colistin. Antimicrobial susceptibility testing using the disk diffusion assay indicated that all 106 E. coli isolates (100%) were sensitive to AMK, 105 E. coli isolates (99.1%) exhibited sensitivity to imipenem, meropenem and doripenem, and 1 E. coli isolate (0.9%) had intermediate resistance to imipenem, meropenem and doripenem; It was observed that all strains (100%) were resistant to cefotaxime. E. coli isolates are resistant to ampicillin (95.3%), amoxicillin/clavulanic acid (95.3%), cefepime (14.2%), cefixime (19.8%), cephalexin (74.5%), gentamicin (42.5%), kanamycin (37.7%), streptomycin (69.8%), tetracycline (80.2%), ciprofloxacin (60.4%), norfloxacin (13.2%), chloramphenicol (59.4%) and trimethoprim/sulfamethoxazole (68.9%). When we investigated the sequence in the Blast database, the genome of the E. coli isolate indicated high similarity with the mcr-4 sequences. To our knowledge, this is the first report investigating on the mcr-4 gene in E. coli identified from cattle in Turkey. Our results highlighted that cattle might be a potential risk in transmitting mcr genes.

Birds of prey raised in captivity have direct contact with the environment and are fed raw meat various animals, which increases the risk of infections caused by parasites, including endoparasites. The aim of this study was to evaluate the prevalence of endoparasites in predatory birds of the orders Accipitriformes and Falconiformes that are used in falconry in Poland. Fresh feces were sampled from 52 birds, including 16 saker falcons (Falco cherrug), 8 lanner falcons (Falco biarmicus), 7 peregrine falcons (Falco peregrinus), 8 Harris's hawks (Parabuteo unicinctus), 7 Eurasian goshawks (Accipiter gentilis), 3 common kestrels (Falco tinnunculus), 1 Eurasian sparrowhawk (Accipiter nisus), 1 red-tailed hawk (Buteo jamaicensis), and 1 common buzzard (Buteo buteo). Fecal samples were analyzed with the use of Fülleborn's floatation technique and the McMaster method (OPG/EPG). Dispersive forms of parasites were identified in 17 out of 52 fecal samples (32.69%). Protozoa of the genus Avispora and Nematodes of the genera Porrocaecum sp and Capillaria were detected. The predominant parasites were roundworms (Porrocaecum sp) which were identified in 27% of the samples. Polish falconers were surveyed to obtain information about bird rearing conditions, the administered feed, contact with wild fauna, incidence of parasitic infections, and the applied treatments. The survey showed that the housing conditions ensured contact with wild fauna, and the majority of owners (63.6%) feed their birds with part of the game they caught. The majority (81%) of falconers did not notice any clinical signs of infection in their infected birds, indicating the need to examine them regularly. The results of the survey were compared with the findings of the parasitological analysis. This study reports on the prevalence of endoparasites in birds of prey, and the present findings can be used by falconers to optimize the management and welfare of predatory birds.

Male fertility is adversely influenced by diabetes. The beneficial effects of antioxidant bioflavonoids in improving fertility have been reported. This study was conducted to evaluate the effects of silymarin on diabetes mellitus-induced male reproductive impairment in rats by investigating its role in Hsp70 and Hsp90 expression. To conduct this study, 18 mature male Wistar rats were divided into three groups: control (Con), experimental diabetes type 1 (T1D-sole)-induced, and silymarin (SMN, 120 mg/kg, orally)-treated T1D-induced groups. The testicular total antioxidant capacity (TAC) and malondialdehyde (MDA) levels were evaluated. Tubular differentiation index (TDI), repopulation index (RI), spermiogenesis index (SPI), and the Johnson score were also investigated. The DNA Ladder test was used to evaluate testicular DNA fragmentation, and RNA damage was assessed through fluorescent staining. Immunohistochemical and RT-PCR analyses were performed for Hsp70 and Hsp90. Oral administration of SMN significantly (p<0.05) increased the TAC ratio and decreased the MDA content in testicles compared to the T1D-sole group. The results showed that T1D increased the percentage of seminiferous tubules with negative TDI, RI, and SPI and reduced the Johnson score compared to the Con group (p<0.05). However, treatment with SMN ameliorated the T1D-induced damages to TDI, RI, SPI, and the Johnson score (p<0.05) compared to the T1D group (p<0.05). The staining intensities and the number of Hsp70+ and Hsp90+ cells were significantly higher in the Con group compared to the T1D-sole animals (p<0.05). However, rats treated with SMN showed an increased number of Hsp70+ and Hsp90+ cells per mm² of tissue compared to the T1D-sole group (p<0.05). Diabetes caused DNA fragmentation and RNA damage, but silymarin reduced its negative effects. In conclusion, SMN ameliorates T1D-suppressed spermatogenesis by upregulating testicular antioxidant status and Hsp70 and Hsp90 expression in testicular tissue. Consequently, it can be considered a potential complementary medication for male patients with T1D.

Pseudorabies virus (PRV) is one of the most important infectious diseases which leads to significant economic losses in the global swine industry. The gE-deleted vaccine is widely used to prevent susceptible pigs from PRV infection. There is no report of the differentiation of PRV wild strain and vaccine strain by recombinase polymerase amplification (RPA) coupled with a lateral flow dipstick (LFD) method. In the present study, the gD and gE gene-targeted primer-probe sets were designed. The RPA-LFD assay could discriminate between the PRV wild strain and the vaccine strain. The RPA reaction conditions were also evaluated. The optimal reaction temperature and reaction time for the RPA-LFD assay were 37℃ and 20 min. The detection limit was 10 genome copies per reaction for PRV wild strain and gE-deleted vaccine strain. The assay did not have cross-reaction with other common swine viral pathogens. The effectiveness of the RPA-LFD assay for detecting the clinical samples was evaluated by testing 80 samples. The result of the assay was compared with that of the conventional PCR. The positive rate of PRV wild strain by the RPA-LFD assay was 20%, whereas the positive rate of PRV wild strain by the PCR assay was 18.8%. The assay therefore provides a novel alternative for differentiation of PRV wild strain and vaccine strain.

Flukes can cause severe and lethal diseases in various animals, including fish. Both adult and larval stages of flukes are found in fish. Haplorchiasis is an infection of fish gills by heterophyid trematodes such as Haplorchis taichui. To detect this parasite, the gills of 30 Tigris kingfish and Tigris barb collected from the Shapour River in Kazerun, Fars province were found to be parasitized with metacercarial cysts of a heterophyid trematode identified as H. taichui. Histopathological examination of the infected fish gills revealed cartilage proliferation, severe hyperplasia, fusion, S-forming, shortening and thickening, distortion, and displacement of affected secondary gill filaments leading to deformities of the filament structure, clubbing, telangiectasis, and hyperemia. Although the gill damage was evident and potentially life-threatening for the cyprinid fish, the examined fish showed no clinical signs. This finding indicates that H. taichui is pathogenic; therefore, prevention of infection and treatment should be a priority.

The aim of this study was to investigate the activity of thymoquinone (TQ), carvacrol (CAR) and thymol (TYM) against multi-drug resistant nontuberculous mycobacteria (MDR-NTM), alone and in combination with berberine (BER). Antimicrobial activity was first evaluated at concentrations from 8 to 512 μg/mL. Each of the compounds tested exhibited good activity against nontuberculous mycobacteria (NTM) isolated from fish, with MIC values of 32-128 μg/mL. In this study, we have shown for the first time the synergistic efficacy of BER with CAR, TYM or TQ against NTM strains. Thus, the combination of these compounds with BER seems to be a new approach for combating MDR-NTM strains.