نشریه میکروبیولوژی دامپزشکی
سال یازدهم شماره 2 (پیاپی 31، پاییز و زمستان 1394)

The aim of this study is identification of Enterococcal species from raw milk of Iranian one humped camel (Camelus dromedarius) and evaluation of their technological properties. A total of 15 Enterococcus were isolated from camel milk of Golestan province in Iran. The log10 CFU of Enterococci per milliliter on KAA medium under anaerobic condition at 20, 37 and 45 °Cincluded 5/816±0/05, 6.397±0/02 and 8/017±0/14 respectively. Therefore, the most of Enterococcal species in camel milk is thermophilic Enterococcus. Isolates were identified on the basis of biochemical and phenotypic characters as E. durans, E. mundtii, E. faecium, E. devriesei, E. avium, E. faecalis. This identification was confirmed by molecular method (amplification16S rRNA gene using B27F-U1492R universal bacterial primer and sequencing of PCR product). These isolated bacteria have lipoliticy activity and high acidifying activity. Enterococcus faecalis showed more lipolytic activity than other isolates. Enterococcus faecium and Enterococcus faecalis showed the highest autolytic activity. Based on technological properties of isolates, Enterococcus bacteria from camel milk are suggested as good candidates for camels milk processing or other dairy fermentation process.

Brucellosis is one of the most common diseases between man and animals (zoonosis) with global spread and broad spectrum of hosts. Although the main way of its medication is prescribing antibiotics to treat patients but due to the occurrence of antimicrobial resistance in bacteria, but medical practitioners are interested in alternative treatments. One way to treat bacterial infections, the use of bacteriophages is instead antibacterial agents in this study. Futurist number 1 (Izat Negar) Iz1 was used in the treatment of experimental brucellosis BALB/C mouse strain Brucella melitensis bacteria of acute biotype1 native national 1. In this study, 4 Group 6BALB/C mice, injected with 104 bacteria intraperitoneal infected as in 100 microliter, consisting of the mice by Rifampin antibiotics and oral Doxycycline treatment. 4 other groups of mice were received intraperitoneal injection of phage Iz treatment. Four control groups (each consisting 10 mice) were included for bacteria, bacteriophage, and antibiotic and phosphate buffer. On the results of this study were treatment antibiotics recipient groups. Groups that were received phages were not treated but in comparison with a control group of bacteria, the bacterial colony count for Brucella was lower in the spleen.

Newcastle disease is common in broiler farms. It causes huge losses to the poultry industry. Because of these, investigating and identifying the disease are important. Moreover, it would be much better to use simpler and cheaper techniques while being more accurate and more sensitive. Therefore, 30 broiler farms, located in Khuzestan province, were sampled and the suspensions were prepared. Then the suspensions were inoculated into 9 to 11 days oldembryonated chicken eggs and after the incubation period were investigated with hemagglutination test. Twelve samples were positive in the haemagglutination test. Finally RT-PCR was performed on the 12 samples to detect Newcastle Disease Virus and the results were positive in six cases. It is important to mention that all six isolates were brain-sourced (also isolated from other tissues) and since all available Newcastle disease vaccines in Iran are lentogen, so the isolates were not from vaccine virus.

The knowledge about antibiotic resistance of common bacterial pathogens in any region is essential. Colibacillosis is one of the most common bacterial diseases in poultry caused by Escherichia coli and is responsible for significant economic losses. The aim of this study was to investigate the antibiotic resistance profile in Escherichia coli isolates recovered from broiler chickens in Ahvaz. For this reason, a total of 120 isolates from 12 broiler farms, 60 isolates from livers of chickens with colibacillosis, and the rest from cloaca of healthy birds were collected. Antibiotic resistance pattern to Doxycycline, Enrofloxacin, Florfenicol, Lincospectin and Trimethoprim-Sulphadiazine, the five common antibiotics in poultry industry of Iran, was investigated. According to disk diffusion test, the maximum resistance was to Enrofloxacin (90.8%), Florfenicol (83.3%), Doxycycline (82.5%), Sultrim (74.2%), and Lincospectin (66.7%), respectively. In the minimum inhibitory concentration (MIC) method, the order was: Enrofloxacin (91.7%), Florfenicol (90%), Doxycycline (87.5%), Sultrim (71.7%), and Lincospectin (69.2%). The results showed that fecal isolates were more resistant than septicemic isolates (p< 0.05). No significant deference was demonstrated between the two methods (disc diffusion and MIC) (p> 0.05). Also, the results showed that 88.3% and 90% of isolates were resistant to more than three antibiotics in disc diffusion test and MIC methods, respectively. It is concluded that for treatment of poultry colibacillosis, antibiotic sensitivity test should be performed routinely.

John’s disease (Paratuberculosis) caused by Mycobacterium avium subspecies paratuberculosis is a granulomatous enteritis in domestic and wild ruminants. In sheep the most common of clinical sings are emaciation and shedding of wool. The aim of this study was to evaluate the seroprevalence of Mycobacterium avium paratuberculosis infection and association of this organism with host and environmental determinants in sheep in Khuzestan province. Serum samples from 568 sheep were randomly collected in Ahvaz, Hendijan, Baghmalek, Susangerd, Gotvand, Masjedsoleyman and Dezfool cities and were examined by ELISA assay, according to the manufacturer instruction. Apparent and true seroprevalence rate of Mycobacterium avium subspecies paratuberculosis was 6.9% and 14.4%, respectively. Statistical analysis showed there was not significant correlation between age, sex, history of abortion and geographical location with serological infection. Logistic regression showed that only 4.3% of fluctuation of infection was justified by these factors. It is concluded that seroprevalence of Mycobacterium avium subspecies paratuberculosis not dependent to host and environmental factors.

Abortion in ruminants occurs for many reasons such that in developed countries despite the relatively complete diagnostic facilities the large number of abortions remains unknown. Most frequently isolated agents include: Brucella spp., Campylobacter spp., Leptospira spp., Listeria spp., Salmonella spp., Chlamydophila spp., Mycoplasma spp. and a variety of viruses and mycotic agents. Coxiella burnetii also cause abortion in ruminants, which is less considered in Iran. To detect the role of Coxiella burnetii in small ruminant's abortion in Hamedan province, 31 samples from liver and kidney and also abomasum contents of aborted fetuses of sheep and goats are taken and test with PCR method. The results of whole samples were negative. Since comprehensive epidemiological study has not been conducted in Hamadan and PCR test was done only on fetus samples referring to the central veterinary laboratories and also the limited number of samples so negative results in this study cannot be the reason for the lack of C. burnetii in the Hamedan province.

Leptospirosis is the most important zoonosis disease that is caused by Leptospira interrogans serovars. Leptospirosis is relatively mild and without any specific clinical signs in the horse, except for blindness due to recurrent uveitis. However, horses plays potential zoonotic role in human health. The aim of this study was to determination of seroprevalence of anti-leptospiral antibodies against six Leptospira serovars in stallions of Tabriz area. Examination of sera obtained from forty male horses were examined using MAT, revealed that 85 percent of animals were seropositive. The highest number of reactors in horses (65%) were due to serovar tarasovi, followed in descending order by australis (50%), icterohaemorrhagiae (25%), pomona (10%) and grippothyphosa (5%) and hardjo (5%). Eight horses had antibodies against one serovar, eighteen horses had against two serovar and six horses had specific antibodies against three serovars. Basis on age grouping of the horses, seropositive animals were 100 percent in 5-10 years, 80 percent in 10-15 years and 77.7 percent in 15-20 years old group. This differences was statically significant (P<0.05). Only four horses had specific antibodies against Leptospira in the aqueous humor of the eyes, which all belong to right eyes. In these positive animals, antibodies were against Leptospira interrogans serovar tarasovi with 1:100 titers. All four horses were seropositive, too. Five horses had signs of ocular involvement and blindness; only two and three horses had specific antibodies against Leptospira serovars in the aqueous humor of the eye and serum, respectively. Result of this study suggested that there were leptospiral infections in horse populations of Tabriz area, which is an important zoonotic and is an occupational hazard to horse owner, farmers, and veterinarians.

This study was conducted to isolate honey bee's pathogenic fungal agents in three seasons (spring, summer and autumn) in Guilan province apiaries. Randomly, we selected five regions and then ten apiaries from each region and four colonies of each apiaries sampled from adult honey bees, brood, honey and pollen and transported to the laboratory. All samples cultivated in SDA (Sabouraud Dexterose Agar) medium. Out of 1469 samples, 76 samples (5.17%) were positive to Honey bee disease fungal agents, 2 (0.14%) Ascosphaera apis causative agent of chalk brood disease and 74 (5%) Aspergillus spp. the causative agent of stone brood disease was isolated. Contamination percent rate in pollen (2.38%), adult honeybees (2.11%), brood (0.48%) and honey)0.2%) were reported. Contamination percent rate to the Honey bee pathogenic fungal agents in summer was reported more than the other seasons.

Today uses of microbial compounds as probiotic are preferred for growth and immune enhancement of fish.The aim of this study was to evaluate effect of different bacterial concentration of Bifidobacterium lactis and Bifidobacterium animalis on growth performance and resistance of rainbow trout against environmental stresses. For this purpose 470 rainbow trout larvae with average mean weight of 0.538±0.197 g (±SD) were obtained and transferred to the laboratory. After 14 days adaptation to the laboratory conditions the fish were randomly divided into four treatments with three replicates (Three experimental treatment and the control). The fish were fed with three concentration of 1×109, 2×109 and 3×109 CFU/100g of probiotic in-feed and the control was fed with diet without probiotic supplementation for 60 days. Length and weight of fish were measured at the beginning and end of study. Also, at the end of study the fish were challenged with environmental stress.The Results showed that the use of the lowest concentration of bacterial increased growth and reduced cortisol in rainbow trout fish blood. Despite of significant growth rate, no significant difference were observed in environmental stresses (P>0.05). Dietary administration of the lowest probiotic concentration could increase the growth and reduced cortisol and ALAT in fish blood.