Tetracycline Resistance Genes in Salmonella enterica Serovars With Animal and Human Origin

Background: Tetracycline is one of the important antibacterial agents which is used against various bacterial infections. Different bacterial species and strains convey various tetracycline resistance (tetr ) genes. Objective: The present study was conducted to evaluate the occurrence of five tetr genes (tetA, tetB, tetC, tetD, and tetM) among Salmonella serovars obtained from humans and animals. Materials and Methods: A total of 60 different Salmonella strains previously recovered from humans, poultry, and animals were subjected to polymerase chain reaction (PCR) and sequence analysis of the genes. Results: In total, 6 strains were positive for the presence of tetA gene; three serotypes were also positive for the presence of tetC gene. The sequence analysis and phylogenetic tree showed similarities between the sequences of serovars in the present study and other Salmonella serovars and some other bacteria species in GenBank data. Conclusion: The results showed the great distribution of tetracycline resistance genes among Salmonella serovars with different sources which could be the effect of widespread use of the antibiotic particularly in the animals breeding farms

New Isolated Extremophiles Arsenic Oxidizing Bacteria for the Removal of Arsenic from High- and Low-COD Media

There is an urgent need for the removal of arsenic (As) from groundwater and wastewater as it is a very hazardous heavy metal for human and environmental health. In this research, As-resistant and oxidizing bacteria were isolated from the Maharloo Lake (27 km southeast of Shiraz city) and identified to a great extent. Three isolated bacillus-shaped strains (called F5, F6 and F7) tolerated up to 1 M AsNaO2, grew up to 3.5 M NaCl and pH 12, and consumed NaSCN and Na2S2O3. The molecular analysis confirmed the originality of the strains to a high extent. The As absorption rate by these bacteria was measured by the atomic absorption method, and their effect was examined on a water sample from the south of Kerman city (Iran) and a synthetic wastewater sample with a chemical oxygen demand (COD) of about 180,000 kg/m3 that was able to absorb high levels of arsenic

Isolation and Identification of Lactic Acid Bacteria from a Traditional Fermented Fish Sauce (Mahyaveh) in Fars Province, Iran

Background: Mahyaveh is a fermented fish sauce in southern parts of Iran. Lactic acid bacteria (LAB) are commonly dominant microorganisms in fermented fish products. These bacteria develop organoleptic characteristics of fermented foods and play a significant role in promoting their quality and safety. The present study aimed to identify LAB isolated from Mahyaveh using 16SrDNA gene sequences. Methods: Mahyaveh samples were collected from different regions of Fars province, southern Iran. Then, LAB colonies were isolated using specific media and identified by microscopic observations and biochemical tests. Afterwards, DNA was extracted, PCR was done by general primers of 16S rDNA, and the bacteria were recognized. Results: The 16S rDNA sequence of all isolates was related to Lactobacillus plantarum and Enterococcus faecium type strains. Conclusion: L. plantarum and E. faecium were shown to be prevalent LAB strains that could be used as starters in Mahyaveh fermentation in southern Iran

A novel fusion protein candidate for the serodiagnosis of Mycoplasma agalactiae infection

Abstract Background The aim of current study was to construct, express, purify and immunogenicity evaluate of a novel recombinant fusion protein including Pyruvate dehydrogenase beta subunit (PDHB) and high antigenic region of lipoprotein P80 of Mycoplasma agalactiae. Using bioinformatics tools, antigenicity and physiochemical properties of fused protein were assessed. Material and methods The recombinant fusion protein of GST-PDHB-P80 were expressed in pGEX4T-1 and purified then verified by Western blot assay. The purified protein was successfully used for immunization of mice. 30 female BALB/c mice were divided into three groups (10 mice per each group) injected with GST-PDHB-P80, inactivated bacteria vaccine and PBS as negative control, separately. Results Western blot analysis confirmed the interaction between the immunized mice serum and the blotted recombinant protein GST-PDHB-P80, demonstrating the immunogenicity of this protein. Moreover, the sera of vaccinated mice with inactivated bacteria vaccine, containing whole cell proteins, detected the recombinant protein GST-PDHB-P80 confirming the antigenicity of PDHB-P80. Negative control displayed no reactivity with GST-PDHB-P80. Conclusion We proposed a novel designed chimeric protein of Mycoplasma agalactiae as a potential marker for serodiagnostic assays but still further field research is required

The Effect of Fluoride-releasing Elastomeric Chains on Streptococcus mutans Levels in Saliva and Dental Plaque in Orthodontic Patients

Background and Aim: During fixed orthodontic treatments the absolute number and percentage of salivary Streptococcus mutans increase. This will cause increase of enamel demineralization and dental caries. The purpose of present study is to evaluate the effect of fluoride-releasing elastomeric chains in the streptococcus mutans levels in saliva and bacterial plaque .   Materials and Methods: In this randomized clinical trial sixty patients, who were under fixed-orthodontic appliance treatments were selected and randomly divided into two groups of 30 each. Conventional elastomeric chains were used in group 1. As for the second group fluoride-releasing elastomeric chains were utilized. Four samples of saliva collected on days 0, 7, 14 and 28, and two plaque samples were collected on the beginning and finishing days in both groups. The fluoride-releasing and conventional elastomeric chains were removed on day 28. All samples were then used for microbial culture to count the Streptococcus mutans colonies. The results were analyzed statistically with the repeated measures Analysis of Variance (ANOVA) and Student t-tests .   Results: The result of Streptococcus mutans (CFU) in saliva at each time point in the study showed no statistically significant difference between the two groups ( p≥0.301 ). Comparison of the effect of elastomeric chains on the Streptococcus mutans colonization in dental plaque and elastomeric chains surface, also did not show any statistically significant difference between the two groups ( p= 0.317and 0.803 respectively) .   Conclusion: There was no clinical evidence that fluoride-releasing elastomeric chains were effective in reducing the formation and colonization of Streptococcus mutans in saliva and dental plaque

Physicochemical characteristics of constructs.

Physicochemical characteristics of constructs.</p

Amino acids involved in hydrogen-bonding interactions.

Amino acids involved in hydrogen-bonding interactions.</p

The map of interactions between ligands and TLR4.

A) ht-Map2191 and B) ht-FAP-P. Green dotted lines represent hydrogen bonds.</p