نشریه بیولوژی کاربردی
سال سیزدهم شماره 3 (پیاپی 51، پاییز 1402)

In recent years ulcerative colitis is a disease common has increased significantly. The risk factors of this disease include; genetic background, environmental factors and bacteria. The important factors in terms of genetic background are family history in first cousins, genetic markers and race and in terms of environmental factors is diet. Based on researches, it is identified that gastrointestinal microbiota is involved in the development of ulcerative colitis and one of the most important bacteria is Escherichia coli with pks gene. pks genomic island is frequently harboured by Escherichia coli strains of the B2 phylogenetic group. pks gene produces a genotoxin as secondary metabolite called colibactin which creates DNA damage in the epithelial cells in the intestine. Mammalian cells exposed to live pks+ bacteria exhibit DNA-double strand breaks and undergo cell-cycle arrest and death. In this study, we investigate the role of E. coli bacteria with pks gene as well as colibactin mechanism on the cell metabolism in the intestine.

 The role of plants in reducing blood lipids and thus reducing the risk of cardiovascular diseases is known. In this regard, the aim of the current study is to investigate the effect of Lipexan capsules in reducing triglycerides, cholesterol and LDL in an animal model.

 In this research, 40 male Wistar rats with an approximate weight of 200±20 grams were used. Mice were randomly divided into 5 groups of 8, including the control group with diet and the control group with high-fat diet (for 21 days), the treatment group with lipexan capsules with a dose of 90, the treatment group with lipexan capsules with a dose of Min and the treatment group with Fibrozil jam capsules (for 30 days) were divided. Blood sampling was done at the end. Cholesterol, triglyceride and LDL values were measured. One-way analysis of variance was used to analyze the data.

 The serum concentrations of cholesterol, triglyceride and LDL in the groups treated with Lipexan Min and 90 capsules and the Fibrozil Jam group were significantly reduced compared to the control group with standard food and the control group with high-fat food.

 Lipexan capsule has an effect on the concentration of cholesterol, triglyceride and LDL in hyperlipidemic rats. Lipexan capsules can be used to reduce the level of blood lipids, as an effective treatment or prevention method for hyperlipidemia.

Pseudomonas aeruginosa is one of the causes of acquired secondary infections. This bacterium causes hospital infections, including surgical wounds, burns, and chronic lung infections. In this regard, the present study was conducted with the aim of investigating the antibiotic resistance and biofilm formation potential of Pseudomonas aeruginosa strains isolated from Kerman hospitals.

This descriptive cross-sectional study was conducted on 70 hospital clinical samples. First, biochemical tests were performed on the samples in order to isolate and confirm the genus Pseudomonas aeruginosa. Antibiotic resistance pattern of strains was determined by disk diffusion method for 11 antibiotics. Then, the ability of biofilm formation in these strains was evaluated.

29 Pseudomonas aeruginosa isolates were isolated from 70 hospital clinical samples by biochemical tests, of which 16 Pseudomonas aeruginosa strains were biofilm producers. The highest antibiotic resistance in the antibiotic resistance test is related to imipenem (17.24%), meropenem (58.27%), cefotaxime (62.06%), aztronam (75.86%), tobramycin (27.2%), respectively. 48%), cefpinem (41.37%), ciprofloxacin (34.48%), cefoxitin (48.27%), ceftazidime (48.27%), cholestin (31.03%), cefamycin (48.27%) was.

The results of the present study indicate an increase in the antibiotic resistance of Pseudomonas aeruginosa to the investigated antibiotics and the spread of biofilm-producing clinical isolates. Therefore, considering the clinical importance of this resistant strain in hospitals, it is necessary to quickly identify it and use appropriate infection control tools to prevent further spread of this organism.

Fungal keratitis is a general term for a fungal disease of the cornea and can be caused by a wide variety of fungi. Keratitis is one of the causes of blindness worldwide. In this regard, the aim of the present research is to achieve an accurate and correct method in the diagnosis of fungal keratitis.

From all patients with keratitis who referred to the Central Eye Bank of Iran from May 1394 to June 1395, in addition to direct examination and culture of a corneal chip sample, the diagnosis was first made by confocal scanning of the cornea, and the sensitivity and specificity of the diagnosis obtained from confocal scanning with Direct experiment and cultivation were compared. Then, using the colonyPCR method, PCR was performed from the colonies of Aspergillus and Fusarium fungi without DNA extraction, with the general primers of fungi (ITS1,4) and the specific primer of Aspergillus genus (ASPf1).

Out of 366 patients clinically suspected of having infectious keratitis, direct test and confocal scan results were positive in 17 patients and culture was positive in 13 cases. 47.06% of the patients were workers. Fusarium genus was the most isolated (47.06%). The rest included Aspergillus (17.65%), Microsporum (5.88%) and Penicillium (5.88%).

Since the delay in the treatment of fungal keratitis causes corneal opacity, reduced vision and absolute blindness, timely diagnosis and rapid treatment of fungal keratitis is necessary.

The most abundant sources used to obtain enzymes with greater stability are thermophilic bacteria. In recent years, microbial L-asparaginase has been widely used as a therapeutic agent in the treatment of human cancers. It is also recently used in the treatment of acute lymphoblastic leukemia. In this regard, the aim of this study is to screen new thermophilic strains capable of producing L-asparaginase enzymes.

Yale Gonbad hot spring was chosen as the isolation site for thermophilic bacteria. Cultivation and morphological and biochemical tests were done to identify the strain. The bacterial strain was screened in order to investigate L-asparaginase enzyme activity by (RPA) method. Modified M9 medium containing L-asparagine and phenol red was used as reagent. Finally, a bacterial strain was identified by determining the 16RrRNA gene sequence after PCR.

Finally, a thermophilic strain was isolated from Yale Gonbad hot spring, which belonged to Bacillus licheniformis. L-asparaginase activity was observed in YT strain and Bacillus licheniformis was produced.

Yale Gonbad hot spring is one of the sources with high potential of useful microbial products that can be used as a useful source of many biological products such as enzymes.

The purpose of the present study was to isolate and identify molecularly native actinobacteria that produce biosurfactant with antimicrobial and anti-biofilm activity against some pathogenic bacteria.

initial screening was done based on oil dispersion test and the best isolate was selected. Ethyl acetate solvent was used for extraction. Antimicrobial and anti-biofilm properties were evaluated using the well diffusion method in agar and 96-well microplate, respectively. FTIR and GC-MS techniques were used for biosurfactant analysis. Finally, the superior isolate was identified using the molecular PCR method.

Biosurfactant of the superior isolate showed the highest and lowest antimicrobial effect at concentrations of 0.4 and 0.3 mg/ml against Pseudomonas aeruginosa and Staphylococcus aureus, respectively. The highest and lowest anti-biofilm effects against Escherichia coli and Pseudomonas aeruginosa bacteria were observed at concentrations of 2 mg/ml. Structural analysis of biosurfactant with FTIR and GC-MS confirmed the structure of amino acid ring with chain of fatty acids and lipopeptide type. The selected isolate was 95% similar to Streptomyces genus and B1AY species.

The local isolate of Streptomyces has a remarkable ability to produce biosurfactant with antimicrobial and anti-biofilm effects against pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli and can be used in the field of pharmaceutical biotechnology.