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Background & Objective: Brucellosis is an endemic disease with a high prevalence in Iran whose highest frequency is in the western region of the country. Genetic diversity investigation is an important method to determine the epidemiological relationship of Brucella isolates in different geographical areas. Therefore, the present study aimed to investigate the genetic diversity of human Brucella melitensis (B. melitensis) strains using the Multiple Locus Variable-Number Tandem Repeat Analysis (MLVA) Typing method in the west of the country. Materials & Methods: In this study, 20 strains of isolated B. melitensis were collected from the human serum samples of suspected Brucellosis in the west of the country and were analyzed by MLVA-16 method. Results: The results showed that 3 genotype numbers 42, 43 and 47 were identified using MLVA-8 method and using MLVA-11 method genotypes 125, 138 and 111 were recognized. Also, 16 different genotypes were detected from the analysis of the isolates by MLVA-16 method which shows a high degree of polymorphism among the isolates due to the high genetic diversity of the isolates in Panel 2B loci. Conclusion: The results showed the high genetic diversity of B. melitensis isolates in the west of the country and their genetic relationship with the known strains in the neighboring countries of the Eastern Mediterranean area, as well as the importance of the MLVA method in identifying the source of infection.

Background: Leptospirosis is a prevalent zoonotic disease caused by Leptospira interrogans bacterium. Despite the importance of this disease, traditional strategies including attenuated and inactivated vaccines have not been able to prevent leptospirosis. Objective: Hence, this study was designed to develop a novel poly-epitope fusion protein vaccine against Leptospirosis. Methods: To do so, the best epitopes of OmpA, LipL45, OmpL1, LipL41 and LipL21 proteins were predicted. Then, the best-predicted epitopes were applied to assemble IFN-γ, MHC I binding, B cell and MHC II binding fragments, and heparin-binding hemagglutinin adhesion was used as a molecular adjuvant. After designing the vaccine, the most important features of it, including physicochemical parameters, protein structures and protein-protein interaction, were evaluated. Finally, the nucleotide sequence of the designed vaccine was used for codon adaptation. Results: The results showed that the designed vaccine was a stable protein with antigenicity of 0.913, which could dock to its receptor. The results also suggested that the nucleotide sequence of the designed vaccine could be expressed in the prokaryotic system. Conclusion: Based on the results of this study, it can be concluded that the vaccine can be a promising candidate to control Leptospirosis.

Brucellosis is a highly contagious bacterial zoonotic infectious disease severely affecting the public health and economic features of endemic and non-endemic countries. The present study assessed ...

Coxiella burnetii pathogen, which causes Q fever, is one of the most dangerous pathogens transmitted from the livestock to humans. The only immunization against this disease is the Q-Vax® vaccine, which is used in Australia, as it is not authorized by other countries due to its adverse side effects. Today, growing attention is being paid to the safety of subunit vaccines. Therefore, performing in silico pre-empirical studies on the functionality of recombinant proteins will be more cost-effective than empirical experiments. In this study, P1 and YbgF antigens of C. burnetii were examined and their epitopes were identified. In this case, the most accurate online tools were employed to predict the B cell, T cell and IFN-γ epitopes. Then, the best epitopes were selected based on their antigenicity potency and resistance to digestive compounds. High-ranked epitopes and Heparin-Binding Hemagglutinin as an adjuvant were used to engineer a poly-epitope fusion protein vaccine. Then, physicochemical features, secondary and tertiary structures of the engineered vaccine were evaluated. Finally, the molecular docking of the engineered vaccine and TLR4/MD2 was done. The results of the different analysis revealed that the engineered vaccine can be potentially considered as a potent candidate for fighting with C. burnetii.

Salmonella is a gram-negative bacterium belonging to the Enterobacteriaceae family. One of the major known serotypes of this bacterium is Salmonella typhi. This pathogen is the main cause of diseases in humans and livestock. It is transmitted from animals to humans through the consumption of contaminated food. At the moment, one way to prevent this illness is using the live attenuated Ty21a vaccine. To eliminate the side effects of the vaccine and improve its safety, it is important to use epitope subunit vaccines. In this study, a wide range of accurate online servers have been used to predict the epitopes of OmpA, OmpC and OmpF antigens of Salmonella typhi. The T-cell (MHCI and MHCII) and B-cell epitopes share a degree of overlap between these tools. The highest scores were chosen for the study. Further analysis of their antigenicity and resistance to digestive compounds was performed by VaxiJen Servers and Protein Digest Servers. Eventually, the resultant epitopes that had desired antigenicity (≥ 1) and showed the highest resistance to digestive compounds were selected. Using these epitopes (MHCI, MHCII and B cell) two different structures (antigenic structure and digestion-resistant structure) were designed by rigid linkers. These structures were based on the highest antigenicity ranking of epitopes and the highest resistance of epitopes to digestive compounds, respectively. Given that this pathogen is primarily transmitted through contaminated foods, oral vaccines are essential in this regard. Therefore, these structures can be considered as suitable candidates for subunit vaccines.

Background: Tuberculosis is known as one of the most dangerous diseases caused by Mycobacterium tuberculosis. Although different strategies have been applied to prevent this disease, it is still considered a killer disease in the world. Objectives: This project was conducted to design a novel poly-epitope vaccine based on three antigenic proteins against tuberculosis. Methods: To design a poly-epitope vaccine, first, the antigenic proteins of Mycobacterium tuberculosis, including Dnak, FbpA, and katG were selected from the database. Then, B cell, MHCI, and MHCII epitopes of the antigenic proteins were predicted using reliable online tools. The best-predicted epitopes were applied to assemble a poly-epitope vaccine. The physicochemical features, the antigenicity of the whole vaccine, and the protein structures of the designed poly-epitope vaccine were evaluated by the most precise tools. Also, the coding DNA sequence of the vaccine was adapted for expression in the prokaryotic system, then, it was theoretically cloned in pET32a (+) vector. Results: The results revealed that the molecular weight and length of the designed poly-epitope vaccine were 32 kDa and 308 amino acids, respectively. The protein structure results demonstrated that the designed poly-epitope vaccine contained 19.48% alpha-helix and 73.05% random coil. Also, the results showed that 92.2% of amino acid residues were located in the favored region. Finally, it was clarified that the antigenicity of the designed poly-epitope vaccine was 12333. Conclusions: According to the results of the current project, it seems that the designed poly-epitope vaccine can be an appropriate candidate to control tuberculosis.

Brucellosis is a highly contagious bacterial zoonotic infectious disease severely affecting the public health and economic features of endemic and non-endemic countries. The present study assessed the potentials of using the touch-down polymerase chain reaction (TD-PCR) compared to the conventional PCR and culture methods in order to detect

Background Probiotics are live microorganisms which are beneficial bacteria that are normal flora of the digestive system which, in determined amounts, show beneficial effects on host health, and can balance gastrointestinal microflora. Digestive tract diseases such as diarrhea are one of the major causes of child mortality in developing countries. Different pathotypes of Escherichia coli cause diarrhea that affects children, therefore reduction of these colonization strains in humans or animals can decline gastrointestinal disorders such as diarrhea. Objective The aim of this study was to determine the antimicrobial effect of probiotic bacterial strains isolated from different natural sources against 4 pathotypes of pathogenic E. coli using disk and well diffusion methods. Methods This cross-sectional study was conducted from December 2013 to July 2014 on Martyr Chamran University in Ahwaz city. A total of 13 probiotic colonies isolated from 20 samples of traditional dairy products including yogurt, cheese and milk, and 20 samples of vegetables including carrots and cabbages (red and white), of which 5 isolates were selected to determine the antimicrobial effect against 4 Escherichia coli pathotypes, randomly. The antimicrobial effect was evaluated using two methods: disk diffusion and well diffusion tests and measuring growth inhibition zones of probiotics against 4 pathotypes of pathogenic E. coli. Results Obtained results showed growth inhibition effects of all 5 probiotic strains against Escherichia coli pathotypes in both used methods. But in comparison Lactobacillus plantarum had higher growth inhibitory effects in both methods. Conclusion results of this study demonstrated high antimicrobial effect of probiotic bacteria against pathogenic Escherichia coli strains. It indicated a positive and beneficial role of probiotics in human health and prevention of illness.

Background : Children's diarrhea is one of the major health problems worldwide, especially in developing countries, accounting for nearly 4-5 million deaths per year.Campylobacter jejuni is a common human bacterial pathogen, which plays at least the same leading role to Salmonella and Shigella as the causative agent of infectious diarrhea. Regarding limited studies on different epidemiologic aspects of this bacterium in Iran, this research carried out to determine infectious enteritis caused by Campylobacter Jejuni in children with diarrhea in Khorramabad city. Materials and Methods: In this study the descriptive survey of the diarrhea caused by Campylobacter jejuni in children less than 12 years of age in Khorramabad city was conducted between September 2004 and September 2005. Stool specimens were collected from patients referred to medical laboratory of Shahid Madani children’s hospital and the correspondent laboratories with clinical symptoms of acute diarrhea. The specimens were transferred to microbiological laboratory of the veterinary faculty of Lorestan university in an attempt to isolate and identify Campylobacter jejuni species. Results:One hundred-thirty out of the total 321 collected specimens (40.5%) were concerned to the female and 191 specimens (59.5%) to the male patients. Campylobacter jejuni species were isolated from 19 (5.92%) of the total collected specimens from which 11(3.43%) and 8 (2.49%) were associated to the female and the male children, respectively. Maximum of the positive cases were reported in the children aged less than 1 year (1.87%) and 1-3 years old (1.87%) that difference based on age groups was significant. Conclusion: According to the findings of the present investigation, the prevalence rate of Campylobacter enteritis in children less than 12 in Khorramabad in 2007 was 5.92 % which is same as the findings of similar studies in Zahedan (6%), Tehran (5%), Sari (4.8%) and Shiraz (5%).