Accepted articles-next issues

Mupirocin is an effective antibiotic for infectious skin diseases. However, mupirocin is formulated as an ointment and is difficult to apply in canine systemic pyoderma. Therefore, many clinicians reformulate mupirocin off-label ointment into a spray. This study aimed to evaluate the antibacterial and antibiofilm effects of different concentrations of mupirocin spray (2%, 1%, and 0.5%) on Staphylococcus pseudintermedius over 21 days. Mupirocin spray was prepared by mixing mupirocin ointment and distilled water. The antibacterial effects were evaluated by measuring the optical density using broth microdilution assay and by live/dead staining. The antibiofilm activity of mupirocin spray was measured using a crystal violet staining method. All concentrations of mupirocin spray inhibited the growth of S. pseudintermedius. Mupirocin spray also inhibited biofilm formation of each isolate, although the degree of inhibition was influenced by mupirocin concentration. The antibacterial and antibiofilm effects of mupirocin spray were maintained for 21 days. The 2% and 1% mupirocin sprays exhibited significantly better antibacterial and antibiofilm efficacy than the 0.5% mupirocin spray. Thus, 1–2% mupirocin spray may be effective for clinical use. Mupirocin spray is convenient and effective for the treatment of canine systemic pyoderma caused by S. pseudintermedius infection.

Nile tilapia Oreochromis niloticus is a popular freshwater fish that has been extensively and intensively cultured worldwide. However, cryopreservation of its sperm especially pre-freezing procedure, has not been properly developed. Therefore, the study aimed to determine the best pre-freezing procedure for cryopreservation of Nile tilapia Oreochromis niloticus. The completely randomized design with five treatments and four replications were employed in this study. The tested treatments were T1= 4 oC → 0 oC → -4 oC → -10 oC → -79 oC → -196 oC, T2= 4 oC→ 0 oC → -4 oC → -10 oC → -196 oC, T3= 4 oC → 0 oC → -4 oC → -196 oC, T4= 4 oC → 0 oC → -196 oC), and T5= 4 oC → -196 oC, with a 10 min equilibration at each respective temperature. Furthermore, sperm was cryopreserved for two weeks in liquid nitrogen (-179 oC). The results of the ANOVA test showed that pre-freezing had a significant effect on sperm motility, and viability (P<0.05), but had no considerable impact on sperm abnormality (P>0.05). Treatment T4 exhibited higher motility and viability, but these values were not significantly different from T3 and T5. Based on practical consideration, it was recommended to utilize the T5 pre-freezing procedures (4oC → -196oC) for cryopreservationof Nile tilapia sperm. Considering these results, Nile tilapia sperm can be directly cryopreserved into liquid nitrogen after equilibration at 4 oC for 10 min.

The aim of this study was to develop a rapid, sensitive and highly specific TaqMan 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 + 41.482, 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 by 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.

Proper management of cattle reproduction has a major impact on the efficiency and profitability of dairy production. Ultrasound examination and transrectal palpation or the pregnancy-associated glycoprotein (PAG) test are currently the most commonly used methods for pregnancy diagnosis. However, alternative methods to those mentioned above are constantly being sought in order to minimise stress during the examination, the cost of veterinary services and to reduce the rate of errors in pregnancy diagnosis. Non-invasive methods of pregnancy diagnosis in cows are being improved, which include the barium chloride test, sulphuric acid, seed germination test, measurement of progesterone, interferon-tau, PAG, early pregnancy factor (EPF), oestrone sulphate, thermography and electrocardiography. Over the past few decades, these methods have been extensively described. Some of these tests require blood, milk or urine for the diagnosis of pregnancy, while others require prolonged contact with the animal in order to take the appropriate measurements. Despite their advantages in terms of simplicity and lower cost compared with traditional methods of pregnancy diagnosis, they are sometimes problematic because of the difficulty of collecting material for testing. They allow the determination of a pregnancy without determining its age or pathology on the part of the development of the foetus and the reproductive system. They are also generally characterised by lower accuracy, sensitivity and specificity, which can have a negative impact on reproductive management and translate into the economics of dairy production. In the context of the above information, it appears that non-invasive methods of pregnancy diagnosis need to be further improved to minimise or eliminate the disadvantages cited.

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. 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.

Poultry scientists are constantly studying different breeds of cockerels that would be suitable for capon meat production. Capon meat, although not yet very popular, is characterized by exceptional taste qualities that could appeal to many customers. Obtaining the appropriate palatability, structure and tenderness of capon meat is possible thanks to the reduction in androgen levels because of the castration of roosters. Surgical or chemical castration affects the metabolism of fats, thus increasing their accumulation in the abdominal cavity, subcutaneous tissue or muscles. The main aim of our research was histological evaluation and analysis of the concentration and distribution of adipose tissue in muscles in Rhode Island Red cockerels and capons. In addition, we analysed the diameter of the pectoral muscle fibre. The experiment was performed on 200 Rhode Island Red cockerels; the testes were removed at 8 week of age. At 12, 16, 20, 24 and 28 weeks of age, 6 cockerels and 6 capons were slaughtered, and samples from the pectoral and thigh muscles were evaluated. Differences in the accumulation of adipose tissue with muscular atrophy (p<0.05) were observed in thigh muscles, with higher numbers in capons than in cockerels. All examined locations in the pectoral and thigh muscles of capons (around the blood vessels, in the perimysium, in the endomysium, and in the sarcoplasm) showed much higher concentrations of lipids compared to the levels in cockerels. The diameters of the pectoral muscle fibres were different (p<0.05) at 12 and 16 weeks of age, and the diameters of the giant fibres were different (p<0.05) at 12 and 20 weeks of age, with higher values in cockerels. The high concentration of lipids in the skeletal muscles of Rhode Island Red capons is impressive. These dual-purpose cockerel breeds can be a source of high-quality meat.

Nicotine, the main toxic component of tobacco, causes directly or indirectly adverse effects on the liver metabolism. Melatonin, secreted by the pineal gland, has anti-apoptotic activity as well as antioxidant activity. In this study, it was aimed to reveal the antiapoptotic effects of melatonin in rats with experimentally induced chronic liver damage with nicotine. In this study, 32 male Wistar albino rats were divided into four groups: control, melatonin, nicotine and nicotine+melatonin. During the experiment, nicotine (1 mg/kg) and melatonin (10 mg/kg) were administered at a dose intraperitoneally for 56 days. At the end of the experiment, the liver tissues were taken for histopathological, immunohistochemical and molecular analysis. The administration of melatonin was determined to partially alleviate histopathological changes in the liver tissue induced by nicotine, such as hepatocyte degeneration, vascular dilatation and congestion, and leukocyte infiltration. It was observed that there was a significant decrease in Bax expression levels and a significant increase in Bcl-2 expression levels in the nicotine+melatonin group when compared to the injury group. On the other hand, it was determined that melatonin administration reduced the Bax/Bcl-2 ratio, which was significantly higher in the nicotine group compared to the other groups, to level close to the control group. Additionally, as a result of immunohistochemical evaluation, it was observed that decreased Bax expression and increased Bcl-2 expression in hepatocytes in the nicotine+melatonin group were at a level close to the control group. Our results revealed that melatonin is a hepatoprotective and effective antioxidant by suppressing cell apoptosis and increasing the rate of healing after damage at both the immunohistochemical and molecular levels.

The present study aimed to search for the presence of the plasmid-mediated colistin resistance (mcr-1 to -9) 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 Türkiye 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 by 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. Minimal inhibitory concentration (MIC) to colistin was detected in mcr-4 positive E. coli isolates by broth microdilution. We have performed the antimicrobial susceptibilities of mcr-4 positive E. coli isolates assessed by the Kirby-Bauer disk diffusion method. E. coli isolate was detected as negative for carbapenem 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 by the disk diffusion assay represented that all 106 E. coli isolates (100%) were detected as sensitive to AMK and 105 E. coli isolates (99.1%) exhibited sensitivity to imipenem, meropenem, and doripenem and 1 E. coli isolate (0.9%) 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%), trimethoprim/ sulfamethoxazole (68.9%) and chloramphenicol (59.4%). 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 searching on the mcr-4 gene in E. coli identified from cattle in Türkiye. Our results highlighted that cattle might be a potential risk in transmitting mcr genes.

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 lateral flow dipstick (LFD) method. In the present study, the gD and gE gene-targeted primer-probe sets were designed respectively. The RPA-LFD assay could discriminate between PRV wild strain and 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, respectively. 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 provides a novel alternative for differentiation of PRV wild strain and vaccine strain.

Porcine circovirus type 2 (PCV2) is the major causative agent of postweaning multisystemic wasting syndrome which leads to significant economic losses in global swine industry. In China, there is a widespread dissemination of PCV2 infection in pig population. Serological diagnosis of the disease is considered as an effective control measure. Here, we developed a capsid protein-based enzyme-linked immunosorbent assay (Cap-ELISA) for the detection of PCV2 antibodies in swine serum using nuclear localization signal-truncated capsid protein produced in Escherichia coli. The Cap protein was expressed as water-soluble and purified through nickel-nitrilotriacetic acid (Ni-NTA) chromatography. After the optimization of the working conditions of Cap-ELISA by chessboard titrations, a total of 649 serum samples were tested by Cap-ELISA and a commercial ELISA kit. The diagnostic sensitivity (DSN), diagnostic specificity (DSP), and accuracy of Cap-ELISA were determined to be 96.7%, 94.1%, and 99.5%, respectively. Cross-reactivity analysis indicated that 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 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 swine industry to monitor PCV2 epidemiology and evaluate PCV2 vaccine efficacy.

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.