Detection and molecular characterization of Clostridium perfringens, Paeniclostridium sordellii and Clostridium septicum from lambs and goat kids with hemorrhagic abomasitis in Turkey.

BACKGROUND: The pathogenic Clostridia cause neurotoxic, histotoxic and enterotoxic infections in humans and animals. Several Clostridium species have been associated with abomasitis in ruminants. The present study aimed to investigate the frequency, and the presence of virulence genes, of Clostridium perfringens, Paeniclostridium sordellii and Clostridium septicum in lambs and goat kids with hemorrhagic abomasitis. RESULTS: A total of 38 abomasum samples, collected from lambs and goat kids of 1 week to 1 month of age in different farms located in eastern Turkey between 2021 and 2022, were evaluated by histopathology, culture and PCR. At necropsy, the abomasum of the animals was excessively filled with caseinized content and gas, and the abomasum mucosa was hemorrhagic in varying degrees. In histopathological evaluation, acute necrotizing hemorrhagic inflammation was noted in abomasum samples. The examination of swab samples by culture and PCR revealed that C. perfringens type A was the most frequently detected species (86.84%) either alone or in combination with other Clostridium species. P. sordellii, C. perfringens type F and C. septicum were also harboured in the samples, albeit at low rates. Beta2 toxin gene (cpb2) was found in three of C. perfringens type A positive samples. CONCLUSION: It was suggested that vaccination of pregnant animals with toxoid vaccines would be beneficial in terms of protecting newborn animals against Clostridial infections. This study investigated the presence of clostridial toxin genes in abomasal samples for the first time in Turkey.

First report of Serotype-1 Marek's disease virus (MDV-1) with oncogenic form in backyard turkeys in Turkey: a molecular analysis study.

BACKGROUND: Marek's disease (MD) is a lymphoproliferative disease caused by Gallid alphaherpesvirus 2 (GaHV-2, MDV-1), which primarily affects chickens. However, the virus is also able to induce tumors and polyneuritis in turkeys, albeit less frequently than in chickens. RESULTS: This is the first study in Turkey reporting the molecular characterization of a MDV-1 strain detected in a flock of backyard turkeys exhibiting visceral lymphoma. Here, MEQ, vIL-8, pp38 and 132-bp tandem repeat regions, which are frequently preferred in the pathotyping of MDV-1, were examined. It was determined that the MEQ gene of MDV-1/TR-21/turkey strain obtained in the present study encoded 339 amino acids (1020 nt) and had four proline-rich repeat regions (PPPP). Based on the nucleotide sequence of the MEQ gene of the MDV-1/TR-21/turkey strain, a phylogenetic tree was created using the MEGA-X software with the Maximum Likelihood Method (in 1000 replicates). Our strain was highly identical (> 99.8) to the Italian/Ck/625/16, Polish (Polen5) and some Turkish (Layer-GaHV-2-02-TR-2017, Tr/MDV-1/19) MDV-1 strains. Also, nt and aa sequences of the MEQ gene of our strain were 99.1 and 99.41% identical to another Turkish strain (MDV/Tur/2019) originated from chickens. Sequence analysis of pp38 and vIL-8 genes also supported the above finding. The identity ratios of nucleotide and amino acid sequences of vIL-8 and pp38 genes of MDV-1/TR-21/turkey strain were 99.64-100% and 99.79-100%, respectively, when compared with those of the Polish strain. According to 132-bp tandem repeat PCR results, the MDV-1/TR-21/turkey strain had five copies. CONCLUSIONS: These results suggested that the MDV-1/TR-21/turkey strain obtained from backyard turkeys can be either very virulent or very virulent plus pathotype, though experimental inoculation is required for precise pathotyping.

Detection and molecular characterization of a highly oncogenic Marek's disease virus from vaccinated hens in Turkey.

Marek's disease (MD) is a highly contagious neoplastic disease of chickens associated with economic losses, often due to visceral lymphomas. The etiological agent is MD virus serotype 1 (MDV-1), also called Gallid alphaherpesvirus 2 (GaHV-2). Despite intensive vaccination, MDV is constantly evolving and maintaining its presence in the world. The aim of this study was to genetically analyze a highly oncogenic MDV/Tur/2019 strain obtained from a poultry farm in Turkey's Elazig province in 2019. Genes associated with viral pathogenicity and oncogenicity Marek's EcoRI-Q-encoded protein (MEQ), phosphoprotein-38 (pp38), and viral interleukin 8 (vIL-8) were selected for this purpose. The vIL-8 nucleotide sequence showed high similarity (100% identity) to some European (EU-1, Polen 5) and Asian (03 India, GADVASU-M2) MDV strains. The pp38 nucleotide sequence showed high similarity (100% identity) to some American (CU-2, JM/102W, RB1B) and European (MD70/13, ATE2539) MDV strains. There were no disrupted four-proline molecules (PPPP) within the transactivation domain of the MEQ. However, according to phylogenetic results, the MDV/Tur/2019 strain was included in cluster 2a alongside European MDV strains (Polish, Hungarian, Italian) with very virulent and very virulent plus pathotypes. In conclusion, we believe that the MDV/Tur/2019 strain obtained from turkey herpesvirus (HVT)-vaccinated chickens has a very virulent or very virulent plus pathotype. Although this result provides some clues regarding the virulence of this strain, in vivo studies are needed to achieve exact pathotyping. Further, combination of HVT with the CVI988 strain should be used for vaccination to provide the best protection, as highly pathogenic MDV strains can break sterile immunity against the HVT vaccine. Keywords: GaHV-2; Marek's disease; oncogenes; Turkey.

Investigation of virulence and cytolethal distending toxin genes in Campylobacter spp. isolated from sheep in Turkey.

The presence of virulence and cytolethal distending toxin (Cdt) genes was investigated in isolates of Campylobacter jejuni, C. coli, C. lanienae, and C. lari that originated from intestinal contents and gallbladders of clinically healthy sheep. These genes have important roles in the pathogenicity of campylobacters. A total of 363 Campylobacter isolates (221 C. jejuni, 135 C. coli, five C. lanienae, and two C. lari) were used in this study. The frequency of racR, dnaJ, ciaB, pldA, flaA, and cadF virulence genes in all the isolates were determined to be 34.4%, 30%, 24.8%, 30.9%, 95%, and 81.3%, respectively, while the virB11 virulence gene could not be detected in any isolates. CdtA, cdtB, and cdtC genes were detected in 54.5%, 55.9%, and 52.3% of the isolates, respectively. None of the virulence and toxin genes examined here were detected in a total of 19 Campylobacter isolates consisting of 10 C. jejuni and nine C. coli. This is the first study investigating the presence of virulence and toxin genes in a large number of Campylobacter species isolated from clinically healthy sheep by scanning a large area. In addition, this is the first report investigating the presence of virulence and toxin genes in sheep-originated C. lanienae and C. lari isolates.

Isolation and molecular characterization of Escherichia coli O157 from broiler and human samples.

There is a lack of information about the role of poultry, specifically chicken, in transmission of Escherichia coli (E. coli) O157 and subsequent human illnesses. This study was therefore aimed at investigating the presence of E. coli O157 and its virulence genes in various samples collected from broiler chickens and humans in Eastern Turkey by culture, immunomagnetic separation (IMS), and polymerase chain reaction (PCR). The genetic relationship between broiler and human isolates was also examined by pulsed-field gel electrophoresis (PFGE). In the PCR analysis of sorbitol-negative isolates, E. coli O157 was identified in 0.1% (1/1000) and 0.4% (4/1000) of the liver and cecum samples of broiler chickens, respectively. On the other hand, none of the carcass samples were determined to be positive for E. coli O157. Overall, the results indicated that 12% (3/25) of the flocks were positive for E. coli O157. The differences between the flocks in terms of the positivity were determined to be statistically significant (p<0.001). Ten (2.7%) of 367 human stool samples were also positive for E. coli O157 in the PCR examination. None of the broiler and human E. coli O157 isolates possessed H7, shigatoxins 1-2, or enterohemolysin genes, whereas all the broiler isolates and one of the human isolates were positive for intimin gene. In the PFGE analysis, a total of eight different profiles (four from broiler and four from human isolates) were observed. However, there were no genetic relationships between broiler and human E. coli O157 isolates. It can be concluded that more detailed studies are needed in poultry to better understand the role of these species in the epidemiology of E. coli 0157 infections in humans.

Isolation of Mycoplasma bovis from broiler chickens in Turkey.

Mycoplasma bovis normally affects cattle, in which it causes pneumonia in calves, mastitis, arthritis and other diseases. In the present article we report the isolation of this bovine pathogen from the tracheas of broiler chickens with no clinical signs. The most probable source of infection was the cattle herd sharing the farm with the chickens.

Genotyping of broiler-originated Campylobacter jejuni and Campylobacter coli isolates using fla typing and random amplified polymorphic DNA methods.

Liver and intestine samples taken from 200 broilers at 20 flocks were inoculated onto Preston Enrichment broth and agar for selective isolation of Campylobacter jejuni and Campylobacter coli. The isolates were identified by both conventional and polymerase chain reaction (PCR) methods. Campylobacter spp. were identified in 102 of 400 samples (200 liver and 200 intestine), 57 (14.25%) of which were identified as C. jejuni and 45 (11.25%) as C. coli. PCR-restriction fragment length polymorphism (RFLP) of the flagellin gene (flaA) and random amplified polymorphic DNA (RAPD) typing were used to describe the heterogeneity among amplified DNA products of C. jejuni and C. coli isolates. Flagellin gene analysis by RFLP of the isolates produced seven different band profiles. On the other hand, five distinct band profiles were obtained in the examination of the isolates with RAPD assay using a random primer (OPA-11). The results of this study demonstrated that a relatively low heterogeneity existed among C. jejuni and C. coli strains isolated from the commercial broiler flocks in eastern Turkey. In the comparison of both typing methods, fla typing provided more discrimination than the RAPD assay used.