It is necessary to understand the frequency of virulence factor-encoding genes in the assessment of the carriage proportion. Moreover, it is required in the characterization of major unique antigens that are useful in the development of effective immunological-based preventive measures. The current study aimed to evaluate the frequency of three encoding-virulence genes associated with Enterotoxigenic (ET) and Shigatoxigenic Escherichia coli (E. coli/EC) pathotypes (k99, stx1, and stx2) in North of Sistan and Baluchistan Province, Iran. The frequency of k99, stx1, and stx2 was determined via polymerase chain reaction among E. coli isolates collected from the feces of the clinically healthy suckling (n=50) and diarrheic calves (n=50). The k99 gene was absent in all isolates, and the frequencies of the E. coli containing stx1 and stx2 or both stx1 and stx2 were estimated at 8%, 14%, and 4%, respectively, in the clinically healthy suckling calves (P>0.05), compared to 24%, 16%, and 6% in diarrheic animals (p <0.05). Among the three studied genes, there was a statistically significant difference between clinically healthy suckling and diarrheic calves in terms of the frequency of E. coli isolatescontaining stx1. On the other hand, the results of this study indicated that k99 was not a major fimbrial antigen-encoding gene in the ETECpopulation in the region. It is assumed that in any health measure intended to control the pathogen, other genes involved with encoding fimbriae should also be considered. The noticeable high frequency of E. coli isolates bearing stx1 and/or stx2 virulence elementsboth in clinically healthy and diarrheic suckling calves in this study isa concern for public health. Accordingly, it is recommended that further epidemiological studies be conducted on the role of the stx1 gene in the diarrhea of suckling calves in Sistan and Baluchistan Province, Iran.In the last couple of years, a number of new and rapid tests for the diagnosis of Tuberculosis (TB) have been developed based on the low molecular weight antigens from Mycobacterium tuberculosis (Mtb) culture supernatant.  https://www.selleckchem.com/products/amg510.html  This study aimed to isolate and purify low molecular weight antigens secreted by Mtb strain C for diagnostic purpose. The secretory proteins from culture filtrate of Mtb were extracted using ammonium sulphate precipitations and sephadex-G50 gel chromatography. The obtained antigen fractions were analyzed for their protein concentrations and approximate molecular weight using Lowry method and SDS-PAGE (12.5%), respectively. DOT-ELISA and Western blot assay was performed to confirm the presence of purified low molecular weight proteins isolated from Mtb using sera from pulmonary tuberculosis patients (polyclonal antibodies). During chromatography, low molecular weight proteins were separated, that was approximately 0.7 mg/ml of the total proteins (1.662 mg/ml). The purified protein fractions in molecular weight range of 14 kDa-41kDa appeared during SDS-PAGE analysis. The chromatographic band fraction in the weight range of 30-41 kDa was identified in the TB patients’ sera using Western blotting. The low molecular weight proteins in the culture filtrate of Mtb strain C were purified using ammonium sulphate and chromatography. These fractions were confirmed using Western blotting. The obtained results might support the hypothesis that the Mtb culture filtrate antigens could be used as a rapid and sensitive assay for the detection of patients with pulmonary TB.About half of the world's population is infected by Helicobacter pylori, which is related to various diseases. The increase in the resistance of H. pylori to antibiotics is alarming and requires new medication candidates. In this study, 83 acidic soil samples (pH 3.9-6.8) were collected from tea and rice farms, located in the semitropical strip in the north of Iran (Lahijan and Fooman cities, Gilan Province). After various pretreatments, including dry heating (120 oC, 10 min), exposure to electromagnetic waves (800 Hz, 3 min), and centrifuging (2950 g, 15 min), 33 acidophilic or acid-tolerant actinobacteria were isolated and their potentials as a source of active metabolites against H. pylori were investigated. According to phenotypic and molecular identification tests, the actinobacterial isolates were classified into Streptomyces and Kitasatospora genera. Among 10 strains that had anti-H. pylori activity, the highest potentials were seen in the strains UTMC 3061 and UTMC 3318. The minimum inhibitory concentrations (MIC) of the related metabolites were 125 and 62.5 µg/ml, respectively. In the checkerboard test, the metabolites of these actinobacteria showed synergism with clarithromycin and reduced its MIC from 1 to 0.5 µg/ml. However, no synergism was seen between the metabolites and amoxicillin or metronidazole. The gas chromatography-mass spectrometry (GC-MS) analysis of the metabolites showed some antimicrobial agents, including carbamic acid, maltol, 2.4-di-tert-butylphenol, methyl dimendone, prolylleucyl, and oleamide. The strains UTMC 3061 and UTMC 3318 showed 99.41 and 100% similarity in 16S rRNA gene sequence to Streptomyces spinoverrucosus and Streptomyces cirratus, respectively. Their metabolites showed good antibiotic activity and limited toxicity and can be considered as promising sources of natural products against H. pylori.The keratinolytic activities of dermatophyte species are accompanied by the secretion of enzymes, such as serine proteases, which are coded by the Subtilisin (SUB) genes. This study aimed to determine the presence of the SUB genes in the clinical and nonclinical samples of Trichophyton verrucosum and Microsporum gypseum. Isolation was carried out by direct and laboratory examination. Following that, for the determination of the presence of the SUB gene, polymerase chain reaction with specific primers was conducted. The frequencies of the SUB gene were observed in almost 66% of the isolates. Statistical analysis showed a significant relationship between the presence of the SUB gene and the samples collected from human, animals, and soil (p ˂0.005). The current investigation has been the first study of the presence/absence of the SUB gene in the clinical and nonclinical isolates of T. verrucosum and M. gypseum in Iran which may be a new step to perform further studies.