Veterinary Research Forum

Abstract This study was conducted in West Azerbaijan province, Iran (37°27'18.022" N, 45°0'0" E) to investigate the genotyping and phylogenetic characterization of Mannheimia haemolytica in cattle and buffaloes from November 2022 to January 2024. Mannheimia haemolytica is a bacterium known to cause pasteurellosis pneumonia, a respiratory disease in ruminants, such as cattle and sheep. This is one of the main causes of economic losses in the feedlot industry. In addition to the deaths, treatment costs are also significant. The lung and nasal swab samples were collected from 378 cattle and buffaloes. The M. haemolytica was detected in 32 (8.46%) of the samples, with a notably higher isolation rate from lung tissue (56.25%; n = 18) compared to the nasal swabs (43.75%; n = 14). Interestingly, the study also revealed a seasonal pattern, with the highest isolation rates observed during January, February, and March. Multi-locus sequence typing demonstrated that all isolates belonged to sequence type 1 (ST1) within clonal complex 28. This finding is consistent with the global prevalence of ST1 in bovine isolates, indicating widespread distribution. Phylogenetic analysis revealed a strong correlation between ST1 and STs 30 and 54, highlighting the prevalence of ST1 in M. haemolytica among ruminants in West Azerbaijan, Iran. Further research is needed to investigate its potential for causing disease and its transmission pattern.

Abstract The poultry products are known as a source of zoonotic and multi-drug resistant pathogens, especially Salmonella spp. The objective of this study was using bacteriophages as an alternative anti-microbial agent against Salmonella typhimurium isolate from turkey poults. The antibiotic susceptibility test was used to identify the antibiotic resistance pattern of the isolates. The bacteriophage was purified, enhanced and titrated using the Spot test and double layer agar (DLA) techniques after being isolated from a chicken slaughterhouse and sewage treatment facility. By determining the morphological characteristics of resulting plaque, the specificity and host range of the phage were studied on S. typhimurium isolates. A total number of 22 suspected Salmonella isolates were confirmed biochemically positive in sample by cultures method. Nine of these isolates (40.90%) were identified as S. typhimurium by polymerase chain reaction. All of isolates (100%) were resistant to chloramphenicol, doxycycline, kanamycin, florfenicol, rifampin, and erythromycin. Seven isolates (77.77%) were resistant to amoxicillin and nalidixic acid. The plaques were present with 3.00 ± 0.22 mm in diameter on the culture of 6 out of 9 (66.66%) isolates of S. typhimurium on brain heart infusion broth using DLA method. The amount of phage titer was 7.60 × 10⁷ phage forming unit mL^-1 and its multiplicity of infection value was calculated as 5.06 × 10^-2 based on obtained results. In place of antibiotics, the multi-drug resistant (MDR) S. typhimurium was successfully destroyed by the isolated bacteriophage from wastewater. In vitro settings were used in this investigation to identify the efficient bacteriophages against MDR S. typhimurium.

Abstract Borrelia species are spirochetes transmitted by ticks that are important in human and animals. In most countries, there is still no molecular epidemiology of borreliosis in ruminants. This study was aimed to evaluate the existence of Borrelia spp. DNA in the blood samples of small ruminants using polymerase chain reaction (PCR) method in West Azerbaijan Province, Iran. To detect Borrelia spp. DNA, about 1,018 ruminants (456 goats and 562 sheep) blood samples were examined from different bioclimatic regions in West Azerbaijan province, Iran. The DNA extracting and PCR were conducted. In sheep, the following prevalence rates were respectively obtained for the 16S rRNA, 5S - 23S rRNA and ospA genes: 3.55% (20/562), 2.13% (12/562) and 0.88% (5/562). And so, the prevalence rates of the genes in goats were 0.87% (4/456) for 5S - 23S rRNA gene, 1.75% (8/456) for 16S rRNA gene and 0.65% (3/456) for ospA gene. The prevalence of Borrelia spp. was significantly different in small ruminants based on the farms and localities. The sheep and goats in humid areas (north of West Azerbaijan) were infected statistically more than those in sub-humid areas (south of West Azerbaijan). It is demonstrated that host species like sheep and goats may have a key role in natural Lyme disease cycles and other borreliosis diseases in Iran.

Abstract Q fever is a worldwide zoonosis caused by an obligate intra-cellular pathogen called Coxiella burnetii affecting a broad range of animal hosts including horses. Most of the isolates found carry plasmids which genetic studies of C. burnetii strains suggest a critical role in C. burnetii survival. The correlation between an isolated plasmid type and the chronic or acute nature of the disease has always been controversial. This study was conducted to investigate the prevalence of C. burnetii QpH1 and QpDG plasmids in horses and assess the potential role of these species as reservoirs of infection and transmission. Nested-polymerase chain reaction (PCR) assays were performed on 320 blood serum samples drawn from horses in West Azerbaijan province, Iran, in 2020. In total, 26 (8.13%) Q fever-positive samples based on containing the IS1111 gene were tested by nested-PCR approach to amplify QpH1 and QpDG plasmid segments. The QpH1 and QpRS plasmid-specific sequences were identified in 19 (73.07%) and none in the serum samples, respectively. According to the present study, the age of the animal can be considered as an important risk factor for the prevalence of C. burnetii; but, the season, sex, and breed of the horse had no effect on the prevalence of disease. The results indicate that nested-PCR method could be suitable for routine diagnosis, to gather new information about the shedding of C. burnetii, and to improve the knowledge of contamination routes.

Abstract There are few studies on Coxiella burnetii (Cb) as a causative agent of Q fever in dairy products in Iran. The prevalence of Cb was studied by polymerase chain reaction (PCR) method in Kope (pot) cheese and cattle milk collected from West Azerbaijan province, Iran. A total number of 240 Kope cheese and 560 milk samples were collected during the year 2020. All samples were subjected to PCR based on transposable gene IS1111. The results showed that 12.50% (95.00% confidence interval (CI): 9.00% - 16.10%) of Kope cheese and 13% (95.00% CI: 10.00% - 17.30%) of milk samples were positive for Cb. There was a significant difference in cheese and milk contaminations with Cb among the defined age groups as well as regional and seasonal variations. It was concluded that Kope cheese and cattle milk are important sources of Cb and should be considered as important risk factors in the epidemiology of Q fever disease in public health.

Abstract Salmonellosis is one of the most important bacterial diseases in human and animals. Rapid diagnosis and sub sequence accurate treatment of Salmonella carriers help reduce the salmonellosis in human and livestock animals. In this study, 420 fecal samples were taken during year 2019 from buffalo in the Urmia, Khoy and Piranshahr regions in west Azerbaijan province, Iran. Samplings were carried out in different seasons. Presence of Salmonella invasion genes (FimA, Stn and InvA) were evaluated by polymerase chain reaction. The bacterial culture and biochemical tests were performed on feces samples for isolation of bacterium Salmonella; however, all samples were negative in culture method. PCR findings showed that, 50 (11.90%) fecal samples were positive to the genes. The analysis of results showed that frequency of salmonellosis outbreak in different parts of west Azerbaijan province followed a similar pattern and the incidence of salmonellosis according to forecast in the warm seasons (spring and summer) was more than in cold seasons (autumn and winter). The prevalence of Salmonella in buffalo’s feces based on warm and cold seasons were 32 (64.00%) and 18 (36.00%), respectively. The results showed significant difference between cold and warm season in the prevalence of salmonellosis. Therefore, the application of molecular technics is essential for the prevention and treatment of salmonellosis. The results also showed that specificity of PCR method was better than culture method for detection of Salmonella in feces sample.

Abstract This study was conducted to investigate the prevalence of subclinical mastitis caused by Staphylococcus spp. in ewes in West-Azerbaijan province of Iran. Molecular characterization of isolated Staphylococcus spp. from diseased ewes were performed using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) and DNA sequencing of glyceraldehyde-3-phosphate dehydrogenase (gap) gene. Also, antibiotic resistance of staphylococcal isolates against different antibiotics was investigated. A total number of 900 milk samples from 450 native ewes in their mid-lactation period were examined by the California mastitis test (CMT). The CMT positive samples were cultured and bacteria were isolated from 86 (9.50%) glands and 74 (16.40%) ewes. The prevalence of subclinical mastitis in the examined ewes was 16.40%. Microbiological analysis of milk samples revealed that 27 out of 74 sheep with subclinical mastitis were infected with Staphylococcus spp. Amplification of gap gene of 27 Staphylococcus isolates generated a single amplicon of 933 bp in size confirming that isolates were belonged to Staphylococcus genus. Digestion of PCR products by AluI endonuclease generated different RFLP patterns for each species. Nucleotide sequencing of gap gene followed by phylogenetic analysis showed that the most dominant Staphylococcusspecies were S. epidermidis, S. xylosus and S. chromogenes. Staphylococcal isolates showed the highest resistance to penicillin and ampicillin. In conclusion, Staphylococcus species, except for the southern parts of the province, play an important role in the development of subclinical mastitis in sheep in West-Azerbaijan province of Iran. Also, chloramphenicol, ciprofloxacin and neomycin are the most effective antibiotics for treatment of this disease.

Abstract Growth inhibition of Aspergillus fumigatus,Aspergillus flavus and Fusarum solani exposed to the essential oils including Thyme, Agastache and Satureja were studied. Disc Diffusion Method was used to evaluate the fungal growth inhibitory effects of the essential oils. Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of the oils were determined and compared with each other. The results showed that all three essential oils examined, had antifungal effects against three fungi species. The MIC data revealed that Thyme oil was the most effective essential oil with the MIC of 62.5 μl ml-1.