ARCHIVES OF RAZI INSTITUTE
Year:2018 | Volume:73 | Issue:2|Papers Count:9

Antibiotic resistance occurs in the endogenous flora of exposed population in addition to pathogenic bacteria. This study was conducted to evaluate the distribution of antibiotic resistance genes among 63 isolates of Escherichia coli of Escherichia coli (E. coli) in diarrheic calves and poultry. According to the results, B1 and B2 were the most prevalent phylogroups of E. coli in calves and poultry carcasses, respectively. Antimicrobial resistance was observed in 76% of the isolates, and 62% of the strains were multi-drug resistant. Antibiotic resistance in E. coli strains obtained from calves strains was significantly higher than those obtained from poultries. Additionally, the strains of B1 and D phylogroups had the highest and lowest antimicrobial resistance, respectively. At least one encoding gene for integrone was detected in 23 strains (36. 5%) and Class I integron had the highest prevalence. Accordingly, this study gave baseline information on the magnitude of the resistance problem and its genetic background in E. coli from domesticated animals of the Tehran, Iran. Moreover, the power of oligonucleotide array technology in the discrimination of different genotypes during a short time was confirmed in this study.

Mycoplasmas are important avian pathogens, which can cause both respiratory disease and synovitis in poultry that result in considerable economic losses to the poultry industry all over the world. The aim of this study was to determine the prevalence of Mycoplasma gallisepticum and Mycoplasma synoviae infections among commercial poultry flocks in Khouzestan province, Iran, using the polymerase chain reaction (PCR) technique. Totally, 290 tracheal swab samples were collected from 19 broiler flocks and 4 layer-breeder flocks, with or without respiratory signs, in different areas of Khouzestan province within six months. The PCR tests were applied for the specific amplification of 16S rRNA (185 bp) and vlhA (392 bp) genes. Out of 100 swab samples obtained from the layer-breeder flocks, 1 and 72 specimens were positive for M. gallisepticum and M. synoviae, respectively. In this regard, out of the 4 layer-breeder flocks, 1 (25%) and 4 (100%) flocks were positive for M. gallisepticum and M. synoviae, respectively. However, none of the studied broiler flocks were M. gallisepticum-or M. synoviae-positive. According to the results, the PCR technique could be concluded as a rapid method for the accurate identification of M. gallisepticum and M. synoviae infections in commercial poultry flocks. The results were indicative of the low prevalence of M. gallisepticum in the studied flocks in Khouzestan province. On the other hand, M. synoviae was widely distributed among layer-breeder flocks in this province.

A cross-sectional survey was performed on domestic pigeons (Columba liviadomestica) to evaluate the prevalence of Haemoproteus columbae and Trichomonas gallinae in West Azerbaijan Province, northwest of Iran between July 2015 and September 2016. Five hundred and sixty oropharyngeal swab smears were examined, 297 (53%) of which were identified to be positive for T. gallinae. Also, the results obtained from blood smears examination indicated that 115 (20. 5%) cases were found to be infected with H. columbae. The rates of T. gallinae and H. columbae infection in female pigeons (58. 3% and 21. 3%, respectively) were higher compared to those in males. There were 76 (26. 1%) and 210 (72. 4%) cases of H. columbae and T. gallinae infection in adolescent birds, respectively, which were higher than those in other age groups. We found high prevalence rates of H. columbae and T. gallinae infections in domestic pigeons. Therefore, more attention should be focused on controlling the spread of T. gallinae and H. columbae infection in domestic pigeons.

Pathogenic bacteria are responsible for a significant number of food poisonings in humans through infected poultries. The main objective of this study was to assess the effect of transportation of chicken carcasses at 18-24, 4-5, and 10-14 oC on the bacterial loads of Staphylococcus aureus, Salmonella species, and Escherichia coli. This study was conducted on 180 fresh chicken carcasses (1197. 0± 19. 88 g) randomly collected from a commercial poultry processing plant in southern Tehran, Iran, in a hot season in 2015. The sampling was performed at two stages, namely post-chilled washing and after 4 h of transportation. In the latter stage, the samples were selected from three vehicles with three types of temperatures. These vehicles included a pickup (18-24 oC), a refrigerated car (4-5 oC), and a refrigerated vehicle with switched off refrigerator (10-14 oC). According to the results, the whole body carcass samples transported at the pickup temperature had the highest mean total count (18. 63×106± 2. 82×106 cfu. ml-1) and was greater (P<0. 05) than the standard limit (5×106). On the other hand, the samples carried by the vehicle with switched off refrigerator had the lowest total count (0. 65± 0. 04×106 cfu. ml-1). Similar results were obtained for S. aureus; accordingly, it reached the maximum (333. 0± 30. 73 cfu. ml-1) at 18-24 oC, which was lower than the national standard limit even after 4 h of transportation. In addition, the cfu values for the total count and S. aureus sampled from the chicken carcasses were lower than the national standard level even after 4 h of carcass transportation, with the exception of Salmonella spp. at the three vehicle temperatures and E. coli at the pickup temperature. It was suggested that the transportation temperature of less than 10-14 oC could not affect the fresh chicken carcass to be contaminated with S. aureus and E. coli.

Iota toxin is produced by Clostridium perfringens type E. This toxin causes antibiotic-associated enterotoxemia in lambs and calves. Iota toxin is a binary toxin that has two components including Ia (the enzyme component) and Ib (the binding component). Ib binds to the surface receptor of target cells and translocate Ia into the cytosol of cells. The aim of this study was to clone toxigenic epitope of iota a gene in E. coli strain Top10. In this study, the phenol– chloroform method was used for the extraction of the whole genomic DNA. The toxigenic epitope of iota a gene was amplified by polymerase chain reaction (PCR). The PCR product was ligated into the pTZ57R/T vector cloning site. Then, based on the TA-cloning method, the product was cloned in competent E. coli strain Top10. Colony PCR was used to screen bacterial colonies transformed with recombinant plasmids. The presence of 446-bp fragment on agarose gel showed that the toxigenic epitope of iota a gene of C. perfringens has been cloned in E. coli strain Top10.

Canine ehrlichiosis is a very important emerging disease in India. This study is the first attempt screening a large number of canines in India for the detection of canine monocytic ehrlichiosis. In the present study, 510 blood samples of dogs were screened for the presence of Ehrlichia canis and other variants of Anaplasmataceae family by serological and molecular methods. Out of the 510 serum samples, 293 (57. 5%) cases were found positive for the presence of E. canis antibodies through enzyme-linked immunosorbent assay (ELISA). Furthermore, and 45 (8. 8%) and 1 (0. 2%) specimens were positive for E. canis and A. platys, respectively, based on the polymerase chain reaction (PCR). In the clinical samples of E. canis, the minimum detection limit for PCR was 9 ng. In the immunofluorescence assay (IFA), the positive blood samples showed comparable results with those obtained from the commercially available dot ELISA kit (giving equivalent IFA titer). The results of sequencing were compared with other reported isolates in various regions of the world, and a phylogenetic relationship was established. The 16S rRNA region that was amplified and sequenced for E. canis and A. platys was highly conserved and so was another Vir B9 region.

Zinc is an essential mineral and accepted as a trace element in the animal nutrition and for its role in biological enzymatic pathways. This study aimed to investigate the effect of oral administration of zinc oxide nanoparticles (ZnONPs) on some of the antioxidant parameters of semen plasma, quantitative and qualitative properties of Arabic ram sperm in the non-breeding season. Twelve adult Arabic rams (about 3-5 years old, 70 ± 2. 1 kg) were randomly assigned to receive one of the three levels of dietary ZnONPs (control; 0, group 1; 40 ppm and group 2; 80 ppm). Results showed that using different levels of ZnONPs increased the activity of superoxide dismutase enzyme (SOD) and total antioxidant capacity (TAC) of semen plasma significantly compared with the control group (P<0. 05). Motility (74. 83%), viability (76. 90%), semen volume (1. 76 ml) and sperm concentration (1418×106/ml) were significantly (P<0. 05) higher in ZnONPs supplemented groups compared with the control group. The sperm morphological abnormalities reduced significantly in treated groups (10. 46 and 9. 07%) compared with the control group (12. 66%; P <0. 05). Also, the results suggested that 80 ppm level of ZnONPs increased the functionality of sperm membrane (44. 38%) compared with other groups (37 and 35. 66%, respectively for groups 1 and control) (P<0. 05). Based on the results, using 80 ppm level of ZnONPs lead to an improvement in the activity of superoxide dismutase enzyme (48. 62 ml) and total antioxidant capacity of semen plasma (111. 88 μ g/ml) compared with other groups (P<0. 05). In conclusion using 80 ppm level of ZnONPs had a positive effect on the quantitative and qualitative properties of sperm and lead to a significant betterment in the activity of some antioxidant parameters of Arabic ram semen in the non-breeding season.

Avian coccidiosis is the most important parasitic disease in poultry production, which inflicts numerous losses to the industry. The extensive use of anticoccidial drugs leads to parasite resistance and drug residue in poultry products. In the present study, we aimed to investigate the effects of three famous essential oils (EOs) and their combination on inactivation of mixed oocysts of Eimeria adenoides, Eimeria dispersa, Eimeria meleagrimitis, and Eimeria meleagridis. The EOs of Thymus vulgaris, Artemisia sieberi, and Mentha pulegium were prepared. After inoculation of each turkey with 7×105 sporulated oocysts, fresh unsporulated oocysts were harvested from their feces. To evaluate the sporulation inhibition effect, 5×104 oocysts were used in each treatment. Each EO was used in increasing concentrations. Half maximal inhibitory concentration (IC50) was determined for each EO and they were blended in pairs based on IC50 line. Our results showed that the IC50 values for mentha, artemisia, and thyme were 22. 92, 40. 5, and 53. 42 mg/ml, respectively. According to our results, artemisia and thyme combination has a synergistic effect, whereas the combination of a high concentration of mentha with a low concentration of thyme had an antagonistic effect. During this study, no interactions were observed between mentha and artemisia.

M. synoviae (MS) is an economically important pathogen and the major cause of airsacculitis and infectious synovitis in turkeys. Infection with this pathogen may remain asymptomatic but can render infected birds susceptible to secondary infections. This study was carried out for the molecular detection of MS infection in commercial and backyard turkey flocks in Tehran, Semnan, Isfahan, Qazvin, Zanjan, East Azerbaijan, Gilan, Mazandaran, and Golestan provinces of Iran. Sixty-hundred tracheal, choanal cleft or/and infraorbital sinus samples were collected from 18 commercial and 31 backyard turkey flocks. The polymerase chain reaction (PCR) technique was performed by using primers specific for detecting the 16S rRNA and vlhA genes of MS. The results showed that 51. 61% of backyard and 33. 33% of commercial farms were MS-positive. These findings suggested the molecular presence of MS, especially in northern and central regions of Iran. Further, the frequency of MS-positive samples was significantly lower in commercial farms than backyard farms (P<0. 05).