نشریه تحقیقات دامپزشکی و فرآورده های بیولوژیک
سال بیست و پنجم شماره 3 (پیاپی 96، پاییز 1391)

Sodium hypochlorite has been used for disinfecting of Cryptosporidium in some contaminated environments by this parasite and also in laboratory works it has been used for the purification of the parasite from bacteria and as a treatment for facilitating of releasing the sporozoites of Cryptosporidium (excystation). The excystation is a critical stage of life cycle of the parasite. The purpose of this study was to determine the efficacy of sodium hypochlorite on the laboratory excystation of sporozoites of Cryptosporidium baileyi. C. baileyi oocysts have been isolated and identified from the bursa of fabricus of naturally infected 30- day- old broiler chickens in Shiraz area. The oocysts were propagated in sensitive 2-day-old chicks and purified by modified sheater’s sugar flotation method. Oocysts were exposed to various concentrations of bleach and incubated at various temperatures for 15 min prior to being washed by centrifuging. Then the oocysts were exposed to the appropriate excystation fluid and releasing the sporozoites were observed by light microscopy. Complete excystation inhibition was seen by 2.5% and 5% Sodium hypochlorite at 37 º C for 15 min. Treatment of oocysts with 1.25% Sodium hypochlorite at 4 º C had no effect on laboratory excystation. In other cases there were some degree of excystation inhibition. The results indicate that 25% commercial bleach or 1.25% Sodium hypochlorite at 4 º C for 10-15 min may be suitable for purification and sterilization of oocysts and also this treatment facilitates and enhances in vitro sporozoite releasing from the oocysts.

Studies have shown that aflatoxin is immunosuppressive and its ingestion in feed has resulted in decreased immunity in vaccinated birds. Therefore، the purpose of the present study was to determine the efficacy of sodium bentonite (SB) and esterified glucomannan (E-GM) of yeast cell wall، in counteracting the toxic effects of aflatoxin (AF) on immunization against Infectious Bursal Disease (IBD) in broiler feed with naturally contaminated diet with aflatoxin. Seven-day-old chicks were randomly assigned to 10 dietary treatments in three replicates of 8 chicks. Treatments were: 1) control; 2) naturally contaminated diet; 3، and 4) naturally contaminated diet (NCD) supplemented with 0. 5 and 1. 0% SB respectively; 5 and 6) (NCD) with 0. 05 and 0. 1% E-GM respectively; 7) NCD supplemented with 0. 5% SB and 0. 05 % E-GM، 8) NCD supplemented with 0. 5% SB and 1. 0 % E-GM، 9) NCD supplemented with 1. 0% SB and 0. 05 E-GM، and 10) NCD supplemented with 1. 0% SB and 0. 1% E-GM. blood samples were taken in 21، 28، 35 and 42 day of age and the titers of antibody against IBD were measured by ELISA test. The addition of E-GM and SB to the aflatoxin-containing diet ameliorated the adverse effects of aflatoxin on IBD antibody titers، but E-GM supplementation to the contaminated diet with aflatoxin proved to be much more effective in the amelioration of the adverse effect of aflatoxin on homoral immunity against IBD. These results clearly demonstrated that simultaneous addition of E-GM and SB (Treatment 8) to the AF-containing diet provided significant reduction on the immunotoxic effects of AF.

Medically and veterinary importance of ticks of the genus of Hyalomma through transmission of related diseases is very obvious. The identification and taxonomy of species of this genus always have been controversial. Sometimes accuracy of morphological diagnosis of two closely related species Hyalomma anatolicum and Hyalomma asiaticum which are reported in fauna of Iran، is very difficult. The objective of present work was to study morphological characteristics of Haller’s organ as a sensory and olfactory organ of ticks for differential identification of both species by scanning electron microscope (SEM). Tick specimens were collected from Araak (Markazi province)، Ghaen (Khorasan Jonoobi province)، Bampour and Iranshahr (Sistan and Baluchestan province)، Qeshm Island (Hormozgan province)، Sarakhs (Northern Khorasan province)، Khuzestan and Lorestan provinces. After diagnosis of male specimens via different systematic references، the Haller’s organs were studied by electron microscopy and outcome photos were prepared. The results of photos shown considerable differences between Haller’s organ capsular pattern of H. asiaticum compared to H. anatolicum. It seems that this measure has potential to identify Hyalomma species and other Ixodids in Iran. Overall، our results suggested using Haler’s organ as a morphological index to separate different Hyalomma species.

Anatomical and histomorphometrical study of sheep’s thymus was conducted by 75 apparently healthy fetuses that collected from Urmia’s industrial slaughterhouse. After anatomical study، the samples were fixed in 10% formal saline، passaged and histological paraffin sections prepared in 5-7 µm in thickness، and by H&E method stained. Histomorphometrical study performed by graded and latticed lens devises. Results of anatomical study showed that thymus begin to develop from cranial part of pericardium in the left side of cranial mediastinum and the ventral surface of neck، and it extend to ⅓ caudal part of neck، then it bifurcate to right and left sides and gain to the pharynx. Histomrphometrical study showed that، mean thickness of thymic lobules in thoracic part at 2nd month of fetal period، significantly was greater than the neck part، whereas، in 2nd half of 4th month in neck part it showed significantly increase (P<0. 05). Mean thickness of cortex and medullae of lobules، from 2nd month until 2nd half of 3rd month in thoracic part was greater، but after that time، until 5th month it was significantly greater in neck part (P<0. 05). Mean thickness of trabeculae decrease as fetus developing. Mean distribution of Hasal’s corpuscles from 3rd month until 5th month were increased، but، mean thickness of these corpuscles were increased until 4th month. This study showed that mean thickness of cortex and medullae of lobules were not significantly different in all fetal periods.

Infection by Toxoplasma gondii is widespread inhumans and many other species of warm-blooded animals. It can cause significant morbidity and mortality in the developing fetus and in immunocompromised individuals، including humans with Acquired Immunodeficiency Syndrome (AIDS) or submitted to cancer chemotherapy. Among livestock، sheep and goat are more widely infected with T. gondii. This parasite is a major cause of abortion، with significant economic losses to sheep and goat breeders. We applied the polymerase chain reaction (PCR) for detection of the pathogenic protozoan T. gondii based on its B gene. The B gene is present and conserved in all six T. gondii strains identified to date. For this purpose 26 suspected human’s blood samples and 54 mice brain and heart were collected from Urmia. In this study، PCR was performed using the previously described primers (Homanet al 2000)، which were designed to detect the B gene of T. gondii. The targeted B gene is highly conserved in all T. gondii strains and is multiple copy genes within the T. gondii genome. The method used for the characterization of T. gondii strains implied digestion with AluIrestriction enzyme of the fragments amplified. The results indicated 19 positive samples (7 human and 12 mouse samples). The 529bp fragment was generated in all positive samples tested and one RFLP patterns were obtained. The results indicated that the same strain of T. gondii can infect human and mouse in surveyed region.

The percentage of fat in liver wet and dry matter، liver moist and dry matter and their relationship were investigated based on species، sex and age of 384 slaughtered animals including 114 cows، 100 buffaloes، 147 sheep and 23 goats from 2008 to 2010 in Urmia، Iran. Mean percentage of fat in liver wet and dry matter، and liver dry matter in cows were 3. 6%، 1. 1%، 29. 7%، buffaloes were 5. 3%، 1. 55%، 29. 2%، sheep were 3%، 0. 83%، 27. 9% and goats were 2. 91%، 1. 55% and 28. 4%، respectively. The highest value for fat in liver wet and dry matter was observed in buffaloes (6. 2%، 20. 5%) and the lowest value for sheep (1. 55%، 5. 14%). The highest and lowest values for liver dry matter were found in cows (38. 2%) and sheep (31. 9%)، respectively. ANOVA analysis showed significant different in liver parameters among ruminants. Variant of sex except for goats did not affect on measured parameters. In individual surveys on measured parameters، 15% of buffaloes and 3. 5% of cows showed over 10% fat in liver، while none of small ruminants appeared over 6% fat in liver. In spite of expected correlations between fat in liver wet and dry matter، liver moist and dry matter، no correlation was observed between fat liver and liver dry matter. Thus، it is concluded that mean value of fat in liver dry matter in small ruminants was less than cows and buffaloes. Maximum mean liver dry matter observed in cows and the minimum in sheep. Mean value of measured parameters among animal species was significant، while age and sex didn’t affect them. It was concluded the occurrence of liver lipidosis in buffaloes is greater than cows and in sheep and goats is so weak. No correlation was expected between fat liver and liver dry matter، and finally، based on liver dry matter، the quality of liver in ruminants sorted from cows to buffaloes، goats and sheep.

Respiratory disease conditions are continuing to cause heavy economic losses in the poultry industry worldwide. Ornithobacterium rhinotracheale (ORT) has been incriminated as a possible additional causative agent in respiratory disease complex. Although، ORT has been proved to be highly sensitive to different chemical disinfectants، currently، ORT infection appears to have become endemic and can affected every new restocking even in previously cleaned and disinfected houses especially in areas with intensive poultry production as well as in multiple age farms. Considering the importance of what mentioned، present study was conducted to detection of Ornithobacterium rhinotracheale in broiler chickens with respiratory infection from Shahrekord، Iran. Altogether 93 tracheal swab samples collected from 31 broiler chicken flocks with respiratory diseases in Shahrekord، Iran. The samples were plated onto Blood agar containing Gentamicin and 5% defibrinated sheep blood and incubated under 5-7. 5% CO2 at 37°C for 48 hours. Suspected colonies were evaluated for detecting ORT by polymerase chain reaction (PCR) method. The rate for respiratory infections with ORT was 19. 14% (18 out of 93). Present study suggests ORT can play a significant role in economic losses caused by respiratory diseases in the poultry industry of the region.