مجله تحقیقات آزمایشگاهی دامپزشکی
سال چهارم شماره 2 (پاییز و زمستان 1391)

Contagious Agalactia (CA) syndrome is an infectious disease with a set of symptoms in small ruminants. In general، 4 strains are considered as it’s causative agents including Mycoplasma agalactiae، Mycoplasma mycoides subsp. mycoides Large colony type or Mycoplasma mycoides subsp. capri، Mycoplasma capricolum subsp. capricolum، Mycoplasma putrefaciensExistence of multiple foci suspected of CA disease in Ardebil province and necessity for finding out their causative agents، made us to isolate and identify the probable agents by using culture method and PCR. Samples were collected only from suspected animals to increase the chance of obtaining the positive samples، and then cultured in PPLO broth and agar after filtration. DNA purification was done by using kit. Identification of the isolates was carried out by DGGE and PCR. Among the 151collected samples only 33 samples grew، 18 of them were mixed. Finally the following results were obtained: 25 isolates were Mycoplasma agalactiae (47. 2% of all isolates) 23 isolates were Mycoplasma putrefaciens (43. 4% of all isolates) 4 isolates were Mycoplasma capricolum capricolum (7. 5% of all isolates) 1 isolates was Mycoplasma mycoides capri (1. 9% of all isolates) These results revealed that Mycoplasmas other than Mycoplasma agalactiae are exist among infected small animals in Ardebil province.

This study was conducted to evaluate the copper (Cu)، zinc (Zn) and Iron (Fe) status in the industrial (n=12) and semi-industrial (n=12) dairy cattle farms from Isfahan city. A factorial experiment in a completely randomized block design consisting four blocks (North، South، West and East) was used. Effects of season in two levels (cold and warm) and cow-rearing practices in two levels (industrial and semi-industrial) on Cu، Zn and Fe concentrations in blood serum of 240 Holstein lactating dairy cows (after second calving، after peak of milk production، averaging 610±50 Kg BW، 30Kg daily milk yield and 170±20 days milking period) were studied. Blood samples were collected from the jugular vein of 5 dairy cows in each farm randomly. In industrial farms diet samples were collected from total mixed rations (TMR) and in semi-industrial farms، the samples were separately collected from forage and concentrates. To assess the Cu، Zn، Fe status in blood serum and diet، concentrations of the elements were determined by atomic absorption spectrophotometry (AAS). The mean concentrations of selected elements in serum were found to be similar in both season in industrial farms. The mean concentrations of Cu and Zn in Serum samples from semi-industrial farms in winter were higher than summer (P<0. 05). The mean concentrations of selected elements in serum were found to be similar in both dairy cattle farms in winter but in summer the mean concentrations of Cu and Zn in serum samples from industrial farms were higher than semi-industrial farms (P<0. 05). No significant differences were observed in the mean concentrations of selected elements in diet of industrial and semi-industrial farms in both seasons. In winter the mean concentrations of Zn in diets of industrial farms were higher than semi-industrial farms and in summer the mean concentrations of Cu in diets of industrial farms were higher than semi-industrial farms (P<0. 05). Comparison between the mean concentration values and critical levels of these microelements (in serum and diet) by t student test showed that none of the values were classified as deficiency and the mean Cu concentration in blood serum were in marginal range (P<0. 05). In industrial farms، the mean concentrations of Cu، Zn and Fe in serum were 0. 540±0. 008 µg/ml، 1. 157±0. 016 µg/ml and 2. 817±0. 119 µg/ml، respectively. Furthermore، 11%nd 2% of copper and zinc concentrations in serum were below the critical levels، respectively. General conclusion of this study indicated that the mean concentrations of Cu and Zn in diet were sufficiently high، the mean concentrations of Fe in serum and diet were in very high levels، the mean concentration of Zn in serum was in normal ranges and the mean concentrations of Cu in serum were in marginal range، this was probably because of high concentration of Fe in diets.

The importance of food is unquestionable. Meat products are one of the major protein resources for human nutrition which nowadays، due to their easy preparation and favorable taste are widely consumed in all parts of the world. Salt is one of the substances added during the manufacture of meat products in order to prolong their maintenance، absorbance of water، and produce a favorable taste. According to the standard number 2303 of the Institute of Standard and Industrial Investigations of Iran، the maximum amount of salt in meat products is 2 percent. Nitrite compounds are food additives use in order to produce a favorable color and taste، prevent the growth of Clostridium botolinum spore، and prolong the shelf-life of products. However، their consumption also leads to the formation of nitrosamines in the body، which are carcinogenic. So they must be use within the legislated standard range (maximum 120 ppm). Another indicator of the ingredients of meat products is the amount of ash. If it will be beyond the standard range، it indicates extra usage of herbal fillers in meat products. Considering the above-mentioned factors، some of popular meat products in Ahvaz were examined. In a 3 month survey، 180 sausage samples from 5 different factories were examined for the amounts of ash، salt and nitrite residues. After ash obtaining of products through Reference Method، the amount of salt and nitrite residues were measured with standard recommendations number 741 and 923 with using potassium thiocyanate titration and spectrophotometric technique respectively. Statistical analyses revealed that the amount of salt and nitrite residues were within the national standard range. The amount of ash was found within the standard range for so-called German (‘almani’) sausages، but more than national standard limits in other products (p <0. 05).

Among foods with animal origin، the egg always has the potential ability to transfer foodborne pathogens which may cause diseases in human. In food industries، eggs is used for different purposes such as production of mayonnaise، spices foods، ice creams and other food products which could be consumed directly without any heating، cooking or half cooking. Salmonella is one of the most common causes of enteritis and food poisoning worldwide. Staphylococcus aureus is one of the three major causes of food borne illnesses around the world and a popular cause of food poisoning in public. The present investigation was performed to determine the probably transferring Salmonella and Staphylococcus aureus to consumers by hen’s eggs. In this research، totally 120 (60 native and 60 industrial) eggs were collected from different part of Qhom areas. The eggs immediately were transferred to microbiology laboratory in the aseptic condition. In order to determine Salmonella، after culturing the internal content of eggs (albumin and yolk) according to the reference conventional methods، the suspected colonies were inoculated in TSI، Urea and LD agar. Then the differential and serological tests were carried out and the Salmonella positive eggs were distinguished. Also about Staphylococcus aureus، after enriching the content of eggs (albumin and yolk) in 10% salt cooked meat medium at 37˚C for 24 hours and inoculation on Baird Parker agar، incubated at 37˚C for 48 hours. Then the suspected colonies were selected and the tube coagulase test was carried out on them. The results showed that one sample of 60 laying eggs (1/66%) was contaminated to salmonella enteritidis، but there was no any contamination in industrial eggs، while 24 (40%) samples of 60 native eggs were contaminated to coagulase positive Staphylococcus aureus، but there were only 2 (3/3%) samples contamination in industrial eggs، therefore according to the obtained results، the consumption of native hen’s eggs could be a threat for public health especially in raw consumption in some foods like mayonnaise، desserts etc. So more seriously monitoring of native egg producers should be considered by responsible authorities.

The objectives of this study were to identify the aerobic bacterial flora of conjunctival sac in healthy horses and to determine the seasonal variations of these flora as well as antibiotic susceptibility of the isolates. Forty-two swabs were taken from the inferior conjunctival sac of 21 normal horses (10 stallions and 11 mares)، in October، January، April، and July. The samples were inoculated on blood agar and MacConkey agar، and examined for aerobic bacteria. A total of 10 different bacterial species (3 Gram-positive، 7 Gram-negative) were recovered. Gram-positive aerobes were most commonly cultured (59. 04% of all isolates). The first five predominant organisms were Bacillus cereus، Staphylococcus epidermidis، Klebsiella oxytoca، beta-hemolytic streptococci and Escherichia coli. According to the statistical analysis، the isolation frequency of B. cereus in spring، E. coli in summer and S. epidermidis in autumn were significantly more than the other seasons (p<0. 05). In winter، there was no significant difference between the frequency of the isolates (p>0. 05). In the stallions، the isolation frequency of K. oxytoca in spring was significantly higher than the other isolates and in the mares، the frequency of S. epidermidis was significantly higher in summer (p<0. 05). On the basis of susceptibility testing، ceftiofor and florfenicol were effective on all bacterial species examined. Gentamicin was effective on all Gram-negative aerobes. The isolated bacterial species were comparable with the studies performed in horses of other countries.

Aflatoxin is considered as one of the most dangerous fungal toxins for human and animals. Crops contaminated with aflatoxin، causing economic losses in agriculture، food and livestock industries. In the present study، the effect of different concentrations of citric acid، propionic acid، and BsP4 strain of Bacillus subtilis on production of aflatoxin B1 by Aspergillus flavus was evaluated. Five treatment concentrations (0، 0. 5، 0. 75، 1 and 1. 25 percent of compounds)، in four replications were used to compare the production of aflatoxin. Appropriate concentration of the compounds were prepared and added to the PDA culture medium (Potato dextrose agar). After 21 days، the produced fungi on the PDA environment culture media were transmitted to rice containing flasks. Four flasks allocated to each studied concentration (20 flasks per each compound). The amount of aflatoxin B1 produced by each of the mentioned groups was measured by thin layer chromatography (TLC). The lowest yield of aflatoxin production (1. 2 ppm) was extracted from strain BsP4 of Bacillus subtilis in 1. 25 percent concentration. The highest toxin production was observed in the basal treatment (60. 8 ppm). The study found that along with increasing in the concentration of citric acid، propionic acid، and BsP4 strain of Bacillus subtilis، the production rate of aflatoxin is diminished to lowest possible rate.

Eclampsia or milk fever is the sudden onset of clinical signs associated with low blood calcium levels (hypocalcemia) that occur more in lactating queens. It is an emergency and occurs when the kittens are 3-5 weeks old (just before weaning). Eclampsia can appear rarely in late pregnancy (pre-eclampsia). In the present study، five household cats with age range between 8 months and 2. 5 years، domestic short hair (DSH) and with 1. 8-3. 8 kg weight were referred to Veterinary Hospital of Shahid Chamran University. Symptoms such as restlessness، hyper-excitability، rapid breathing، uncoordinated gait، pale mucous membranes، muscle tremor and lack of appetite were seen. A plain radiograph of the skeletal was normal. Electrocardiogram was recorded to check cardiac arrhythmia which was normal. In this disorder، the level of total maternal calcium had suddenly dropped (less than 7 mg/dl). Aspartat aminotransferase enzyme (AST) was increased (>55 IU/l) in all cases. Three out of 5 cats had hypocalcemia after parturition. The queens had a large litter. Only two cats had hypocalcemia at the end of pregnancy. Supportive treatments (Slow intravenous administration of calcium gluconate and Vitamin D) were administered for all of them. Their kittens were removed at once، and were feed with a milk replacement by the owners. Level of total calcium was normal after treatment.