مجله تحقیقات آزمایشگاهی دامپزشکی
سال پنجم شماره 2 (پاییز و زمستان 1392)

The purposes of this study were to detect the frequency of aerobactin production and the presence of iucD gene, which is involved in biosynthesis of aerobactin system, among Escherichia coli isolates from cases of avian colibacillosis. Fifty E. coli isolates recovered from pericarditis lesions of poultry colibacillosis were collected from broiler farms in provinces of Tehran, Alborz, and Ghazvin and were tested for their ability to produce aerobactin and the presence of iucD gene. Phenotypic determination was performed according to the method described previously. The isolates were examined by PCR for the presence of iucD gene. Out of 50 E. coli isolates, 43 (86%) had ability to produce aerobactin. PCR showed that out of 50 E. coli isolates, 48 (96%) possessed aerobactin encoding gene (iucD). However, the iucD gene was not detected in two isolates that were negative in phenotypic examination. The findings of the present study showed that high percentages of avian pathogenic E. coli isolates are able to produce aerobactin. Considering similar studies completed by other researchers, especially the comparative studies with E. coli isolates from apparently healthy animals, a strong association between the aerobactin production and virulence of poultry E. coli isolates is emphasized.

Salmonella spp. is Gram-negative bacteria and belongs to entrobacteriaceae family. Salmonella spp. is one of the most important zoonotic agents with worldwide distribution. The aims of this study were to isolate Salmonella from poultry farms around Ghaemshahr city, identify the serotypes, and determine the drug resistance patterns of the isolated Salmonella spp. A total number of 2280 samples were randomly collected from freshly dropped feces of broiler chickens in different flocks. Each 10 samples were pooled and processed for Salmonella isolation according to the standard procedures. Serotyping was performed by slide agglutination test to determine the O and H antigens of the isolates. The antigens included A to D polyvalent, and O2, O4, O5, O9, O12, H2, H6, HL, Hgm monovalent antisera. Antimicrobial susceptibility of the isolates against 30 antimicrobial agents was determined by using standard disk diffusion method. Out of 2280 samples (228 pooled-samples), 30 Salmonella isolates were recovered. Serotyping revealed that two isolates were Salmonella spp. enteritidis and 28 isolates belonged to serogroup C. All 30 Salmonella isolates were susceptible to levofloxacin and Fosbac. Also, the highest resistances were related to streptomycin, furazolidone, nalidixic acid, tetracycline, and lincospectin. Multi-resistance to drugs was common among the Salmonella isolates and ranged between 2 to 17. There were 29 resistance patterns. The results of this study showed the presence of Salmonella spp. infection among broiler chickens in Ghaemshar regions and the occurrence of antimicrobials resistance among the isolates. These findings are important for Iranian poultry industry and of concern to public health.

Aflatoxin B1 (AFB1) is one of the most important fungal toxins that can contaminate food and feed. The purpose of this study was to evaluate different methods of measurement and production of AF on the rice media for the implementation in the research studies. Reference strains of Aspergillus flavus obtained from fungi collection of the Centre of Scientific and Industrial Research Organization in Iran (PTCC NO: 5004 (IR111)) proliferate on Potato dextrose agar (PDA) medium and used for in vitro studies. Also, growing fungus was transferred to the rice media for production of AFB1. The results showed that the major environmental factors affecting production of AFB1 in rice cultivation are temperature and incubation conditions (ambient light level). In addition, aflatoxin production under the same humidity conditions in the dark environment with temperature of 24oC reaches to the greatest possible extent. In contrast, the worst circumstances to produce AF, were detected a bright environment with temperature of 40oC. The study revealed that temperature and light are main factors in the production of AF.

Toxoplasmosis is an important zoonotic disease with worldwide distribution. It is capable of infecting an unusually wide range of warm-blooded animals including most livestock, and humans. Many studies were shown high prevalence of Toxoplasma infection in man and animals in Iran. The present study was conducted to investigate a serological survey of antibodies in Turkoman breed horses in Raz and Jarglan area, the North Khorasan Province. One hundred blood samples were collected with cooperation of the Veterinary Office from 2011 to 2012. The sera samples were tested for antibodies against T. gondii using Indirect Immunoflurescent Antibody Test (IFAT). The seropositive reaction against T. gondii were detected in 41 (41%) sera. The antibodies tites were detected in the range of 1:20 dilution and 1:160 dilution. In the present study, the lowest and highest seroprevalence of T.gondii infection were observed in the age groups of <1 year old and 1 -10 years old, respectively (P<0.05). There was no significant difference between the seroprevalence of Toxoplasma infection with gender and kind of activity factors in sampled horses. Regards to high seroprevalence of Toxoplasma infection in sampled horse; it needs to pay attention to animal health for control and prophylaxis of disease.

Toxoplasmosis is a zoonotic disease which is caused by a protozoa named Toxoplasma gondii. There is no clear information on the prevalence of this infection in cattle and sheeps in Lorestan province. Therefore, in this study we intended to determine the prevalence of toxoplasma infection in domestic animals (sheep and cattle) slaughtered in khorram Abad. In total, 446 blood samples were collected from sheeps (286) and cattles (160) which were slaughtered in Khoram Abad’s abattoirs. Sera were separated and tested for the presence of specific IgG anti-toxoplasma gondii by an enzyme-linked immunosorbent assay (ELISA) technique. According to the guidelines of serologic kit manufacturer, 16.1% of sheeps and 11.9% of cattles were infected by Toxoplasma gondii. There was a significant relationship between seropositivity for Toxoplasma gondii and the age of animals (P=0.002). The infection rate was higher in older animals. The seroprevalence rate of infection was lower than the reported rates for many parts of the country. But, the true infection rate may be slightly different from the value we determined, because serological tests may have some problems.

Hydatidosis is one of the most important zoonoses worldwide. Since there is no published data based on serological tests of camels’ hydatidosis in Yazd province, presence of specific antibodies in animals’ blood sera were examined with Indirect Hemagglutination and Counterimmunoelectrophoresis assays. A total of 141 sera samples from apparently healthy dromedary camels of different ages and both sexes were investigated for anti-Echinococcus granulosus antibodies. Eighteen (12.8%) and sixteen (11.3%) camels found to be seropositive with Indirect Hemagglutination and Counterimmunoelectrophoresis respectively. Statistical analyses showed that camels of Less then 10 years old being positive significantly higher than animals of other age groups (P <0.05). This preliminary study indicates that camels may play an important role in human infections in the area, although further studies are necessary to characterize the seroprevalence of the infection more thoroughly.

The penis of the camel have a three parts; root, body and free-part. The camel penis has rotary movements during the mating in the female genital duct. Therefore, the nerve fibers distribution and how lies in the free part of penis are important. For accomplishment this study, the free-part of five camel penis were provided from semnan slaughterhouse and then were accomplished all phases of tissue preparation (histotecknic) so as, fixation, dehydration, blocking, sectioning and staining with hematoxilin and eosin(H&E).The study of transverse histological sections in this investigation were shown, the most numbers of nerve fiber bundles are presence in distal extremity (Glans of penis) of free-part. Dorsal, lateral and ventral nerve fiber bundles are presence in proximal extremity of free-part of penis. Transverse histological sections of middle part of free part, were shown present lateral nerve fiber bundles. And in this part, dorsal nerve fibers were reduced. Therefore, the pudendal nerve in the free-part of camel penis, was inclined to lateral aspect from proximal extremity to distal extremity of free-part of penis.