فصلنامه دنیای میکروب ها
سال سوم شماره 4 (پیاپی 9، زمستان 1389)

Influenza virus H9N2 is a low pathogenic avian influenza that its first outbreak in Iran was reported in 1998 and caused appreciable economic losses in the poultry industry. Vaccines are one of applicable approach for protect the avians from avian influenza viruses. This study aimed to evaluate a killed avian influenza vaccine (produced in Razi vaccine and serum research institute) against current isolates in Shiraz.

In this study, fifty broiler chickens were divided into 5 ten-bird groups including test and control groups. Forty broiler chickens (group 1, 2, 3 and 4) were vaccinated with the killed oil-emulsion influenza vaccine that was obtained from Razi Vaccine and Serum Research Institute. Ten chickens were used as control group (Nonvaccinated group). After two weeks both vaccinated and control chickens were inoculated with H9N2 influenza viruses that were isolated from chickens farms of Shiraz in 2010. The cloacal and tracheal swab samples were collected from chickens at 1,3,5,7,9,11 days after infection and were processed for virus isolation.

The results showed that after five days for group 1 and after seven days for groups 2, 3 and 4, virus shedding into tracheal and cloacal samples was significantly decreased. However, the shedding continued for 11 days in control group.

The results suggested that the killed oil-emulsion influenza vaccine could efficiently decrease AI replication and its shedding in the broiler chickens.

Introduction and

Malignant sheep and goats theileriosis is one of the most important protozoan diseases of sheeps in Iran. Theileria lestoquardi is the only intracellular eukaryotic pathogen that is able to transform its host cells reversibly. Therefore, design of a cell line of ovine lymphocyte that is transformed by the T. lestoquardi is very valuable.

The breeding ticks was infected by feeding on the sheeps that were carrier of Theileria lestoquardi sporozoite in order to obtain homogeneous infected ticks. Then, ovine lymphocytes were infected with Theileria lestoquardi sporozoite stabilate to produce lymphocytic cell line containing T. lestoquardi.

 This research resulted in the development of a new ovine lymphocytic cell line called as Booket. Molecular study confirmed that the cell lines were transformed by T. lestoquardi. The gene sequence of this isolate has been submitted to GenBank with accession no. GU233776.

In this study the second lymphocytic cell line containing T. lestoquardi was established in Iran.

Lactic acid bacteria are characterized as gram positive, usually non motile, non-spore forming bacteria that affect the health conditions of their hosts due to production of lactic acid and other fermentative yields. The aim of this study was to isolate Lactobacillus strains from stool sample of children and to determine their antimicrobial activity against common pathogenic bacteria such as Escherichia coli, Salmonella typhimurium and Helicobacter pylori.

The bacteria were isolated from the stool samples via cultivation on MRS agar media. Identification of the lactobacilli was performed based on their morphological, physiological and biochemical characteristics. Inhibitory effect of isolated lactobacilli on pathogenic bacteria was assessed by well diffusion and disk diffusion methods. After centrifuging the cultured bacteria and their sedimentation in the tubes, the pathogenic bacteria were plated on MRS agar. Following adding 100µl lactobacillus supernatant to the wells, the results were interpreted after 24-48 h.

19 samples out of 40 samples (47.5 %) had inhibitory effect on the studied pathogenic bacteria. L. plantarum, L. fermentum and L. rhamnosus were isolated more than other species. Maximum inhibitory effects of lactobacilli were observed against Escherichia coli and Salmonella. The widest antimicrobial hollow were obtained when the pathogenic bacteria were exposed to the supernatants of L. rhamnosus and L.fermentum.

In conclusion, the result showed that Lactobacillus strains are useful for treatment of persistent diarrhea and gastrointestinal disease and their consumption as dairy products would be effective for both prevention and treatment.

Since E. coli K99 is a causative agent of diarrhea and casualties in calf, it has adverse impacts on economy. This research studied the pathogenic factors of the E. coli by Multiplex PCR, and determined protein pattern of different E. coli isolates by SDS-PAGE (sodium dodsil sulfate polyacryl amid gel electroforesis).

300 rectal swabs were collected from 1-30 days-old calf during a period between 2010 to 2011. One part of the samples was studied with Multiplex PCR method for determination of the K99, F41 as well as STa genes, and another part was cultured for E. coli isolation and SDS-PAGE assay.

The PCR results indicated that 16 of the 200 isolated E. coli had K99, F41, and STa pathogenic factors. LT was not found in the isolates. SDS-PAGE results showed different protein pattern in the isolated E. coli strains. The results of SDS-PAGE column showed only one band for K99 antigen.

Based on the found virulent factors in the isolated E. coli K99, it has been shown that the isolates contain at least three pathogenic genes (K99, F41, and STa). Although no significant difference has been seen between the isolates in terms of gene investigations, there was a meaningful difference in the protein patterns of the isolates. As a conclusion, different bacteria showed different protein patterns and consequently had different pathogenic ability.

Escherichia coli is a causative agent of over 80% of urinary tract infections in all ages of the society. Strains of Escherichia coli are divided into four phylogenetic groups. Most of pathogenic extra-intestinal strains often belong to groups D and B2. This study aimed to define the phylogenetic groups of E. coli isolated from urinary tract infections in south of Iran.

This cross– sectional study was carried out on the patients with urinary tract infection who admitted to peymanieh hospital of Jahrom in 2010. Specific biochemical tests were used for identification of bacteria. The phylogenetic groups of E. coli strains were determined by the PCR method and using two specific primers yjaA ChuA and TspE4.C2.

Out of 60 identified E. coli, 78.34% were isolated from women while just 21.76% were isolated in men. The most common identified groups were classified as D (70%), A (23.3%) and B1 (6.7%), and none of the species belonged to the B2 group.  Data analysis revealed no significant relationship between phylogentic groups with the variables age, sex, history of urinary tract infection, previous history of antibiotic use and hospitalization.

The results showed that most of the E. coli strains isolated from urinary tract infections in this region belonged to phylogenetic group D. Also, the results obtained from this region was different from other area.

usarium crown rot caused by F. oxysporum f.sp. radicis-lycopersici is one of reasons of decrease in tomato yield worldwide.. Cultivation of resistant tomato cultivars is the best way to control this disease. Molecular markers linked to resistance genes would be useful for improving tomato breeding programs. This study was conducted to identify resistant (existence Frl gene) and sensitive varieties of tomatoes using RAPD marker.

DNA was extracted using CTAB method from 27 tomato varieties. PCR technique was used to identify F. oxysporum f.sp. radicis-lycopersici. Then RAPD marker UBC 194 was used to amplify resistance gene Frl. Results were confirmed by pathogenicity test.

In this study, based on UBC 194 marker it was found that 20 out of 27 tomato varieties and hybrids contained a 590 bp index band (existence of resistance gene Frl). Pathogenicity test showed that the tomato varieties that the resistance gene Frl was found in them had no symptoms while the varieties that did not contain the gene showed disease symptoms with different disease index.

Plantation of resistant varieties in the infected areas can control this disease without using fungicides.