نشریه میکروبیولوژی دامپزشکی
سال هفتم شماره 2 (پیاپی 23، پاییز و زمستان 1390)

On the base on published reports by parasitologists، clinicians and executive and health authorities، parasitic infections of ruminants of Iran were divided to four groups including: high، medium، low and very low significant based on pathogenesis، prevalence rate and portability. Results showed that totally 27 infections including: 16 helminthes، 8 protozoa and 3 acarins were reported in ruminants of Iran. Moreover، 9 helminthes، 4 protozoa and 3 acarins of them was zoonotic. Accurate and rapid diagnosis، establishment of specific laboratories for important infections، using GPS for faster information about infected centers، use of rapid response plan، strategic control and treatment of parasitic infections، use of new generation vaccines، tracking method of animal''s resistance against anti parasitic drugs، their bio control and implementation of the relevant international guidelines are necessitate for foresight control of above-mentioned parasites.

Domestic poultry constitutes the largest reservoirs of Salmonella serovars which exist in nature. Many methods are available for controlling the vermin such as rats and mice، but the entrance of the feral birds such as sparrows (Passer domesticus) to the farms are inevitable. Contaminated feed stuffs are undoubtedly a common and important route by which a poultry flock becomes infected with Salmonella. The purpose of the present study was the isolation and identification of Salmonella from sparrows which exist in the broiler breeding barns. The study was based on random sampling from 40 farms. From each farm، five samples were collected (totally 200 samples). Sparrows were trapped by creel and swabs were taken from rectum-cloaca region. The swabs were deposited in Rappaport-Vassiliadi (RV) broth and transferred to the laboratory within 24 hours beside the ice bags. After incubating in 43 °C for 12-16 hours، streaked on selective and differential media including Mac Conkey agar and XLD agar were performed. After incubation، suspected colonies were transferred to triple sugar-iron (TSI) agar and then suspected isolates were confirmed by means of biochemical tests. The results of present study showed that all the sparrows were free from Salmonella.

Lactoperoxidase enzyme is present in various mammalian glands and in their secretions. The lactoperoxidase system is a natural anti-microbial system in milk which results from the interaction between three components; the enzyme lactoperoxidase، thoicyanate ion and hydrogen peroxidase. Hydrogen peroxidase catalyzes the oxidation of thiocyanate to turn it into the antibacterial hypotiocyanate that، in turn، inhibits the growth of bacteria. Lactoperoxidase enzyme was extracted from the milk of camel. Camel milk was centrifuged at 2500 rpm at 4°C for 15 min to remove fat. Camel lactoperoxidase was extracted from raw milk using CM sepHadex C-50 ion exchange chromatography٫ and sephadex G-100 gel filtration chromatography. The activity of lactoperoxidase was measured by using tetramethylbenzidin as achoromogenic substrate. The determination of molecular weight for the extracted enzyme was controlled with SDS-PAGE. Km value for lactoperoxidase was 0. 268 mM. Vmax value was 0/000149 µmol/ ml min. The antibacterial system was prepared. The complete system constituted lactoperoxidase٫ H2O2٫ and tiocyanate. The antibacterial complete system effect was measured on the Staph aureus bacteria. For this purpose، the bacteria were incubated under complete system condition for 360 min. The findings indicated that the antibacterial complete system effect on Staph aureus was 70%. These results showed a significant difference as compared to the control.

In the present study، the morphometrical polymorphism of Trichostrongylidae isolated from abomasums of 300 sheep was determined. In so doing، 300 cases from three various climatic regions of Iran (100 cases from Rasht (first region)، 100 cases from Kazeroon (second region)، and 100 cases from Ahwaz (third region) were selected and their abomasum''s parasites were gathered. The parameters used in male nematodes were length، width، spicule length، the distance between anterior barb and head، esophageal length، as well as copulatory bursa and the ones used in female nematodes were length، width، distance between genital pore to end of body، esophageal length، egg length and width. Haemonchus contortus and Marshallagia marshalli in both genders and male Ostertagia (Teladorsagia) circumcincta were commonly seen among sheep in all regions. In both sexes of Haemonchus contortus and Marshallagia marshalli and male Ostertagia (Teladorsagia) circumcincta، the results showed statistically significant differences among the parasites of all three regions regarding their related parameters.

In the present study، the morphometrical polymorphism of Trichostrongylidae isolated from abomasums of 300 sheep was determined. In so doing، 300 cases from three various climatic regions of Iran (100 cases from Rasht (first region)، 100 cases from Kazeroon (second region)، and 100 cases from Ahwaz (third region) were selected and their abomasum''s parasites were gathered. The parameters used in male nematodes were length، width، spicule length، the distance between anterior barb and head، esophageal length، as well as copulatory bursa and the ones used in female nematodes were length، width، distance between genital pore to end of body، esophageal length، egg length and width. Haemonchus contortus and Marshallagia marshalli in both genders and male Ostertagia (Teladorsagia) circumcincta were commonly seen among sheep in all regions. In both sexes of Haemonchus contortus and Marshallagia marshalli and male Ostertagia (Teladorsagia) circumcincta، the results showed statistically significant differences among the parasites of all three regions regarding their related parameters.

Marek’s disease is an immunosuppressive disease in birds. The Cytolytic form will remove the B & T lymphocytes from the age of the 4 weeks. So the broiler flocks which are not vaccinated against this disease are to be infected with this disease. The study is intended to investigate the Marek’s vaccination effect on the broiler’s performance and the performance of chick’s immune system. A farm test was designed with 4 aviculture coliseums with the equal conditions. Chicks were randomly divided in to 4 groups of 5،000 chicks. 2 of them were vaccinated with HVT+R vaccine of Marek’s disease and 2 of them were regarded as control. FRC coefficient، weight gain، mortality rate and feed intake were evaluated weekly. The HI test was applied to determine Newcastle disease antibody titer as humeral immune system، and the LPA (MTT) test was used to evaluate the performance of cellular immune system. The results showed only a reduction in the mortality rate and FRC coefficient of the vaccinated groups with no statistically significant variation (p>0. 05). ND_HI test also showed no significant difference (p>0. 05) between the vaccinated groups and the control groups. However، the MTT test showed a significant (p<0. 05) increase in chicks’ immune systems in vaccinated groups compared to the control groups.

Avian pneumovirus (Metapeumovirus) is characterized by respiratory signs، rhinotracheitis in turkey (TRT) and Swollen Head Syndrome (SHS) in chickens and may cause drop in egg production in layer and breeders. In this study، 360 serum samples were prepared from 24 broiler chicken flocks، slaughtered in 50-60 days old from different areas of Isfahan province. Serum samples were tested with avian pneumovirus enzyme-linked immunosorbent assay kit (IDEXX). The results shows، from 360 broiler chickens، 122 (33. 9%) were positive for avian pneumovirus antibody. In this study، 83. 3% of all sampled farms possessed at least one positive serum sample. With regard to the prevalence of avian pneumovirus in broiler chicken flocks، it is important to investigate pathogenesis of avian pneumovirus to design a suitable strategy for controlling this infection.

Pigeons can be carriers of some human pathogens and contribute to transmission and spread of drug resistant infectious agents to human. Campylobacter bacteria are the most common bacteria that cause gastroenteritis worldwide. Considering people''s interests to keep pet birds and the potential ability of pet birds to transmit Campylobacter to humans، the present study was conducted to evaluate Campylobacter infection in Shahrekord''s pigeons by polymerase chain reaction (PCR). Altogether 150 samples of pigeon faeces were collected were collected with sterile cotton swabs from different areas of Shahrekord، Iran and evaluated for detection of Campylobacter by bacteriological and PCR methods. Campylobacter was isolated from 0. 7% (1 out of 150) of samples. Campylobacter isolates showed high level of antibiotic resistance. This study showed domestic pigeons of Shahrekord can harbor low level of Campylobacter infection.