نشریه تازه ها در میکروب شناسی دامپزشکی
سال ششم شماره 2 (پاییز و زمستان 1402)

Besnoitiosis is a chronic to severe and usually non-fatal disease in cattle, which is caused by the protozoan Besnoitia besnoiti and causes severe skin and systemic manifestations. The Bb-Ger1 isolate was obtained from the Razi Vaccine and Serum Research Institute and was first propagated in the culture medium with the cell line (MARC 145) and then counted using Neubauer chamber, seven groups of ten from Ross 308 standard embryonated eggs from Iran Animal Science Research Institute and on the ninth day of hatching, the eggs were divided into the first to sixth groups, respectively (ten, one hundred, one thousand, ten thousand, one hundred thousand, one million) dilutions of parasite tachyzoites in the amount of 200 microliter and the seventh group were inoculated only with sterile PBS as a control group. Eggs were examined daily and tissue samples from brain, heart, liver, and skin were fixed in 10% formalin and evaluated for histopathology. The mortality of fetuses in the groups receiving the parasite was significantly different from the control group (P<0.05) and the death of the fetuses and the severity of tissue lesions in different groups were not dependent on the parasite dose and had no significant difference (P>0.05). Histopathological lesions were observed in various tissues, including hyperemia, hemorrhage, edematous cells, and necrosis. The present study showed that the embryonated egg cannot be a suitable environment for the growth and reproduction of Besnoitia besnoiti parasite.

The aim of this study was to evaluate the correlation between the fungal contamination rate of various parts of simental male cows genital system with viability and sperm motility and also testosterone concentration in blood serum and semen plasma. Sampling was performed from external skin of penis, internal skin of penis, penis before ejaculation, fluid pre ejaculation, ejaculation fluid (semen), penis after ejaculation, and ejaculation fluid after defreezing from male cows. For mycological examination, all samples were cultured onto sabouruad dextrose agar medium containing chloramphenicol (0.005%) and kept at 30oC for 7-10 days. Sperms motility using CASA software and the percentage of abnormal and viable sperms using Eosin nigrosin were performed. Also, testosterone levels of blood serum and semen plasma samples were assessed by quantitative chemiluminescence method. The most frequently isolated fungi were Candida spp. (35.6%), Penicillium spp. (18.6%) and Aspergillus (14.2%). The highest and lowest mean rates of fungi were associated with internal skin of penis (21.08 ± 16.43) and ejaculation fluid after defreezing (2.00 ± 2.45), respectively. Although there was no correlation between the total amount of the fungal contamination and sperm motility parameters before and after freezing, a positive significant relationship was observed between viable sperms percent after freezing and testosterone concentration of semen plasma (P<0.05). The findings showed that there is a significant correlation between fungal community rate and viable sperms and testosterone level of semen fluid.

Brucellosis or malt fever (Mediterranean fever) occurs due to the growth and multiplication of the gram-negative coccobacillus Brucella in mammalian cells, and this disease is important as a common disease between humans and animals. Several serological tests have been investigated to identify this bacterium, however, these methods have limitations in the accurate identification of the bacterium. The present study was conducted with the aim of investigating and molecular identification of Brucella bacteria in samples collected from infected sheep in Sistan region using multiplex PCR technique. At first, blood and milk samples were collected from infected sheep. Confirmation of bacterial infection was initially done using blood samples and Rose Bengal serology method. Next, DNA was extracted from the collected milk and molecular analysis was performed using multiplex PCR and amplification of Omp31 and BLS genes, in order to amplify fragments with sizes of 347 bp and 256 bp respectively. Out of the 40 clinical samples, all of them showed a positive Rose Bengal test, but molecular analysis using multiplex PCR showed 5 false positive samples confirmed with the Rose Bengal test. Due to the higher sensitivity and accuracy and short time of identification the molecular methods can be used as a suitable option for identifying pathogens.

Reptiles are hosts for a wide variety of intra- or extracellular blood parasites that range from protozoan parasites  to microflarid nematodes.  Hemogregarines are found in many vertebrates, being the most prevalent apicomplexan parasites in reptiles. In this study, the prevalence and intensity of  hemoparasites in Caucasian Agamid lizards, Paralaudakia caucasia was investigated. Blood smears were prepared, stained by gimsa, and were examined for the presence of haemoparasites. The light microscopic diagnosis detected parasites in two groups: Hepatozoon sp and Lankestrella sp were found as apicomplexan blood parasites and microflarial worms as nematods.  The prevalence of infected lizards was 17.50 and 10 percent for Hepatozoon sp and Lankestrella sp. respectively. As well as 10 percent of lizards were infected by nematod worms. This report is the first survey of haemoparasites in these lizards. It revealed a high diversity of haemoparasites in lizards of the study region and highlighted the need to understand their impacts on hosts.

Along with the global expansion of aquaculture, diseases have increased in this industry. Vaccines and antibiotics are used as accepted methods throughout the world to fight disease. However, in Iran, the path of fighting diseases has gone into the use of antibiotics. Antibiotic overuse puts evolutionary pressure on pathogenic and non-pathogenic bacteria, resulting in the emergence of antibiotic-resistant strains and a more severe recurrence of the disease. On the other hand, antibiotics also affect the function of vaccines. Together, these events affect the economic aspects of fish farming. So, antibiotic use is important in terms of environmental impact and public health, the immune system, vaccines, and aquaculture economics. In this review paper, an attempt had been made to study previous research on antibiotics and vaccines, economic analysis of vaccine uses and its health effects, by answering the question "Vaccine or antibiotics: which one should be used in fish farming?" Shows the importance of using vaccines instead of antibiotics.

This study investigated the effects of using rapeseed meal instead of soybean meal on meat quality, morphology, and ileum microbial population in Japanese quail using 675 Japanese quail in a completely randomized design with 9 treatments, 5 repetitions, and 15 quail per repetition. The treatments consisted of a control group fed with a corn and soybean meal-based diet without additives, as well as rapeseed meal replacing soybean meal at 25, 50, 75, and 100 percent both with and without protoxin probiotic (200 mg/kg) supplementation diets from 7 to 35 days of ages. Treatments without probiotics had no effect on quail meat pH and percentage of loss due to cooking and the rapeseed meal without probiotic had no effect on meat quality of quail (P>0.05). The treatment fed with the control treatment and the 25% rapeseed meal treatment with probiotics had the highest percentage of water retention capacity, lover loss due to cooking and higher amount of lactobacillus counted(P<0.05). The control treatments and 25% rapeseed meal had lover amount of malondialdehyde and 25, 50 % rapeseed meal treatments with probiotic had lover Escherichia coli count (P<0.05). Also 25% rapeseed meal with probiotic treatment increase villi height and decerse crypt depth compare with other treatments(P<0.05). In conclusion, this study suggests that inclusion of 25 % rapeseed meal instead of soybean meal with probiotic supplementation can positively affect meat quality, morphology, and microbial population in the ileum of Japanese quail we can use this available protein meal in the Japanese quail ration.

Salmonella is one of the gram-negative pathogens, whose presence in food reduces the quality of production and the occurrence of gastroenteritis in humans. The prevalence of salmonella in dairy products and the antibiotic resistance of this bacterium is one of the current crises. The purpose of this study is to investigate the prevalence of Salmonella Typhimurium and Enteritidis in traditional and industrial dairy products sold in Shahrekord city and the antibiotic resistance of the isolates. In this study, 140 samples from different traditional and industrial dairies were isolated and transferred to the food hygiene laboratory under sterile conditions, and the samples were evaluated for bacterial isolation by standard methods, and the resistance of the isolates was performed by disk diffusion method. took The results showed that out of a total of 60 industrial dairy samples, 2 samples (3.33%) were contaminated and 38 samples (47.5%) out of 80 traditional dairy samples were contaminated with Salmonella, and the highest contamination was related to industrial curd (6.42%). And then there was traditional butter and cheese (71.5%); Also, the highest level of resistance was related to sulfamethoxazole (71%) and the lowest resistance was related to Amoxiclav (50%). The results of this study showed that the detection of bacteria by PCR method is preferable to other traditional methods and considering the high occurrence of antibiotic resistance for the treatment of gastroenteritis caused by salmonella, the use of antibiotics for treatment should be minimized.

Campylobacter bacteria is the main cause of campylobacteriosis disease in human and animals. Pet animals include dogs and cats may be carriers of contamination and transmitted bacteria without clinical symptoms.considering the increasing desire of people to keep dogs and cats at home,the purpose of this research was to determine the frequency of campylobacter infection in pets and their owners. In this research,122 feces samples of pets and owners analyzed with microbial and molecular methods. In the microbial method,the frequency of campylobacter infection in cats and dogs was derermined to be8 and 12% respectively, and the molecular method,determined to be 36 and 44%. In the owners of pets,the frequency of infection was determined to be 20 and 32%respectively,while campylobacter infection was not observed in people unrelated to pets.Campylobacter jejuni was the most common species in all case of campylobacter infection.the result of the chi square test(pearson test)showed a significant relationship between the infection of pets and infection oftheir owners(p<0.01 ).Finally,due to the significant frequency of campylobacter infection in pets and considering the role they can play for the health of human societies periodic test of very important.