مجله تحقیقات دامپزشکی
سال هفتاد و هشتم شماره 2 (تابستان 1402)

The protozoan Haemoproteus belongs to the Phylum Apicomplexa, Class Sporozoa, and Order Haemosporina. Avian haemosporidian are protozoan parasites that use birds as hosts around the world. Many species of wild and domestic doves are natural hosts of different species of Haemoproteus. Blood-sucking arthropods are the main vectors of these blood parasites. The aim of this study was the microscopic and molecular investigation of the protozoan Haemoproteus columbae in the blood of infected pigeons in Torkaman County, Iran. Blood samples and tubes containing ethylenediaminetetraacetic acid (EDTA) anticoagulant were collected from 96 domestic pigeons randomly from 14 pigeon lofts and different parts of Torkaman County.Pigeons were also inspected for infection with the host-vector Pseudolynchia canariensis. In the next step, blood smears were stained with Giemsa and examined microscopically. Also, blood tubes containing EDTA were tested by PCR method on the cytochrome b gene. Microscopic and molecular examination of peripheral blood showed that 62 (64.58 %) and 73 (76.04 %) of the investigated pigeons were contaminated, respectively. Of the 62 infected pigeons infected with the Haemoproteus, 28 pigeons (66.66 %) were male, and 34 (62.96 %) were female. Also, the infestation with Pseudolynchia canariensis was observed in 4 (28.57 %) pigeon lofts. The preliminary investigation shows the high rate of Haemoproteus infection in pigeons in Torkaman County. Further studies to determine the prevalence and accurate identification of the species infecting pigeons in this region require PCR testing and sequencing of infected blood samples.

Infectious diseases and microbial antibiotic resistance are the major problems of fish farming industry annually causing remarkable losses. Apart from the economic losses caused by these infections, some of these agents are zoonotic and may be transmitted to humans. This study was aimed to identify the common causative agents of infections in rainbow trout farms and to determine their antibiotic resistance toward some common antibiotics. Sampling was performed during a nine-month period between March and December 2021 by visiting and inspecting rainbow trout farms and the affected fish with disease symptoms were obtained from the farmed fish in Mazandaran, Lorestan, Chaharmahal and Bakhtiari and Zanjan provinces. Bacterial culture was undertaken from anterior kidney or spleen organs and the isolated bacterial strains were identified by phenotyping, biochemical and molecular assays. Antibiotic resistance pattern was evaluated by disk diffusion method (DDM) and minimum inhibition concentration against erythromycin, oxytetracycline, florfenicol, enrofloxacin and nitrofurantoin. Seventy-four bacterial isolates of Gram-positive cocci or Gram-negative coccobacilli were isolated. In phenotyping, biochemical and molecular (PCR) assays Lactococcus garvieae (12 isolates, 16.2 %), Aeromonas hydrophila (9 isolates, 12.2 %), Streptococcus iniae (17 isolates, 23 %), Streptococcus agalactiae (20 isolates, 27 %), and Yersinia ruckeri (16 isolates, 21.7 %) were identified. The majority of these isolates were obtained from the fish farms in Mazandaran province. Erythromycin and oxytetracycline with 87.8 % resistance were antibiotics with the highest resistance, while enrofloxacin with 24.3 % resistance revealed the lowest level of resistance. Antibiotic resistance rates for florfenicol and nitrofurantoin were also 43.2 % and 44.4 %, respectively. The highest antibiotic resistance was detected in the bacterial isolates of Lactococcus garvieae, Aeromonas hydrophila, Streptococcus iniae, Streptococcus agalactiae and Yersinia ruckeri, respectively. This study shows that the spread of streptococcosis, lactococcosis, yersiniasis and Aeromonas septicemia and their frequent treatments has led to an increase in antibiotic resistance, especially against commonly used drugs such as erythromycin and oxytetracycline.

Respiratory pathogenic beta-hemolytic streptococci in horses, including Streptococcus equi subsp. equi, the causative agent of strangles disease, Streptococcus equi subsp. zooepidemicus is an important cause of respiratory disease and Streptococcus dysgalactiae subsp. equisimilis has been isolated from nasal swabs taken from horses with a history of respiratory disease.

The present study aimed to determine the frequency and risk factors of respiratory tract infections originating from beta-hemolytic streptococci in the provinces of West Azerbaijan, East Azerbaijan, and Ardabil.

During this study, 121 horses with clinical respiratory symptoms were sampled. After performing clinical examinations and recording clinical signs in special worksheets, sampling of the upper part of the respiratory tract was performed using nasopharyngeal swabs. The samples were sent to the laboratory in a standard transfer medium with cold chain.

In this study, out of 121 samples collected from horse breeding clubs from 10 different regions of northwestern Iran, 51 were negative for beta-hemolytic streptococci while the results were positive for the other 70 samples (P<0.001). Regarding the positive samples for beta-hemolytic streptococci, the results of differential cultures were as follows: eight cases of Streptococcus equi subsp. equi, 57 cases of Streptococcus equi subsp. zooepidemicus, and five cases of Streptococcus dysgalactiae subsp. equisimilis. There was no significant relationship between the frequency of beta-hemolytic infections with variables of gender, race, and geographical area (P>0.05). Meanwhile, the statistical test showed a significant relationship between the frequency of infection with these bacteria and the variable of clinical symptoms (P<0.001). Moreover, the frequency of beta-hemolytic streptococcal infections was significantly associated with age (P<0.05).

The results herein suggested that the bacterial cause of the majority of respiratory infections in infected and sampled horses in the provinces of West Azerbaijan, East Azerbaijan, and Ardabil at the time of sampling was Streptococcus equi subsp. zooepidemicus and that this organism is a potential pathogen for respiratory diseases in horses in these provinces.

Poultry farming is one of the most productive and economic agricultural sectors. However, the bacterial contamination and the activity of darkling beetles (Tenebrionidae) as a potential reservoir of Salmonella in meat poultry farms can inflict direct and indirect damages. The present study aimed to identify the darkling beetles and their accompanying Enterobacteriaceae contamination in Isfahan chicken farms. Darkling beetles were collected and identified based on their morphological aspects from different parts of 16 poultry farms (4 from each geographical area) in Isfahan Province, Iran. Then, 80 samples of darkling beetles were cultured on selective-differential media culture of the Enterobacteriaceae family using the homogenization and enrichment method. The isolated bacteria were identified based on physiological and molecular characteristics. Also, specific antisera were used to determine serological groups. The results revealed that all collected darkling beetles’ samples belonged to the species Alphitobius diaperinus (Col., Tenebrionidae), and from 80 microbial culture samples from the beetles, isolated bacteria belonged into 4 genera: Escherichia sp. (20 isolates, 25 %), Klebsiella sp. (8 isolates, 10 %), Proteus sp. (22 isolates, 27.5 %), and Salmonella sp. (30 isolates, 37.5 %). Among them, the Salmonella genus accounted for the highest percentage of darkling beetles’ contamination. In the serological assay, the isolated Salmonella were classified into two serogroups, A (23 isolates, 76.67 %) and C (C2 and C3) (7 isolates, 23.33 %), which the A serogroup was the most frequent. In this study, the A. diaperinus species was isolated and identified for the first time from poultry farms, and this pest, with a high percentage of Salmonella infection, is introduced as one of the reservoir sources of bacterial contamination in the broiler farms.

Heparin is a sulfated glycosaminoglycan. Blood is a common source for DNA detection in all kinds of samples, and anticoagulants such as heparin and ethylenediaminetetraacetic acid (EDTA) are used to prevent coagulation. Because heparin has a strong inhibitory effect on polymerase chain reaction (PCR), it is not used in samples that will be tracked by DNA. There are physical, chemical, and enzymatic methods to eliminate the inhibitory effect of heparin on PCR test. First, to compare the intensity of the inhibitory effect of two anticoagulants, heparin, and EDTA, on the Real-Time PCR (qPCR), and then to investigate the impact of the heparinase enzyme present in the medium culture extract of Pseudomonas aeruginosa, on removing the inhibitory effect of heparin during the real-time PCR. In the present study, two blood samples containing heparin and EDTA were subjected to a real-time PCR test to check the intensity of the inhibitory effect. Then, the medium culture extract of Pseudomonas aeruginosa was added to the heparinized blood sample infected with Escherichia coli bacteria in two groups with different conditions. In the first group, the DNA in the heparinized blood sample was extracted by the phenol-chloroform isoamyl alcohol method. Then, these samples were incubated with the extract of Pseudomonas aeruginosa bacteria culture medium at different hours, but in the second group, the samples were incubated at different hours before DNA extraction. Also, the DNA concentration in both groups was measured by a Nanodrop device, and finally, all samples were subjected to a real-time PCR test. The results of the research samples showed that although the heparinized blood sample contains more DNA concentration than the EDTA blood sample, it completely prevents genome replication. Also, incubating heparinized blood with Pseudomonas aeruginosa culture medium extract before DNA extraction for more than 24 hours removes the inhibitory effect of heparin during the real-time PCR, even at a lower cycle threshold than the EDTA-containing sample. The Pseudomonas aeruginosa culture medium extract may enable researchers to use heparinized blood samples for genome amplification and diagnosis without using expensive and limited commercial heparinase enzyme.

Protection from reproductive damage is essential in chemotherapy medicines for cancer patients. This study aims to examine the effect of curcumin on the structure of the ovary of mice after treatment with goserelin and cyclophosphamide. One hundred and ten BALB/C mice with 3 regular consecutive periods of the estrous cycle were divided into 11 groups of 10 each. No medicine was used in the control group. The treatment groups were as follows: 1) cyclophosphamide, 2 to 5) cyclophosphamide with curcumin with a dose of 100, 200, 300, and 400 mg/kg, respectively, 6) goserelin, 7 to 10) goserelin together with curcumin with a dose 100, 200, 300, 400 mg/kg, respectively. The luteinizing hormone (LH) and follicle-stimulating hormone (FSH) of serums were evaluated using ELISA. Morphologic and morphometric of ovaries were assessed. The total number of follicles, primary, secondary, periantral, and antral follicles, in the goserelin and cyclophosphamide group, was significantly reduced compared with the control group (P<0.05). Cyclophosphamide and goserelin with different doses of curcumin showed a significant increase in the total number of follicles, primary, periantral, and antral follicles compared to the group treated with cyclophosphamide and goserelin alone (P<0.05). Curcumin (200, 300, and 400 mg/kg) and cyclophosphamide, compared to the cyclophosphamide group, significantly increased the quality of zona pellucida (P<0.05). Cyclophosphamide and goserelin caused a significant decrease in FSH and LH (P<0.05). Cyclophosphamide with different doses of curcumin showed a significant increase in LH compared to the group treated with cyclophosphamide alone (P<0.05). Goserelin with a 400 mg/kg curcumin dose significantly increased LH compared to goserelin alone (P<0.05). The amount of FSH in the cyclophosphamide groups with curcumin increased compared considerably to cyclophosphamide alone (P<0.05). The groups of goserelin with curcumin showed a significant increase in FSH compared to those of goserelin alone (P<0.05). Curcumin can protect the reproductive system of mice from the damage caused by the administration of cyclophosphamide and goserelin.

Clostridium perfringens (C. perfringens) is an anaerobic Gram-positive bacillus with spores, whose biotype A is responsible for a variety of diseases, including intestinal inflammation, bloody diarrhea, and gas gangrene, and hemorrhagic bowel syndrome. Genetic variety can explain the bacteria’s phenotypic diversity, geographic distribution, host specificity, pathogenicity, antibiotic resistance, and virulence. A molecular method using the pattern of DNA bands classifies bacteria based on the size of fragments produced by enzymatic digestion of the genome. This study aims to standardize the polymerase chain reaction (PCR)- restriction fragment length polymorphism (RFLP) method in identifying the genetic diversity of C. perfringens biotype A isolates. The genomic DNA of the investigated strains was extracted, and the complete sequence of the alpha toxin gene locus was synthesized using specific primers designed by PCR technique. Enzymatic cleavage of the synthesized amplicons was performed with the Mse l restriction enzyme, and the resulting fragments were separated by electrophoresis and analyzed by ImageJ and NTSYSPC software. The findings showed that the alpha toxin gene locus sequence may change and is not conserved. In this research, 4 different patterns were identified based on enzymatic cleavage. Mutations in this locus can lead to diversity in C. perfringens biotype A and the creation of new strains. The results of this research showed that the alpha toxin gene locus could be considered a DNA molecular marker in C. perfringens, and the PCR-RFLP technique can be used as a tool for typing this bacterium and estimating the phylogenetic relationships through comparative studies of nucleotide sequences.