فصلنامه دنیای میکروب ها
سال پانزدهم شماره 1 (پیاپی 50، بهار 1401)

Following the global spread of the new coronavirus, extensive international and national efforts were made to develop a vaccine against the virus. Pharmaceutical giants such as Pfizer, Johnssen Biotech, Astrazeneca, Sinovac, Modrena, Biontec, Bharat, Finlay and China National Biotech Group, along with research institutes such as the University of Oxford and the Gamalia Research Center, are examples of these companies and centers that were able to be more successful than other competitors in the speed race to make and produce Corona vaccine. In Iran, the attempts to make this vaccine were quickly made and Iranian companies and organizations such as Shafa Pharmed, Imam Khomeini Executive Headquarters, Ministry of Defense, Pasteur Institute and Razi Vaccine and Serum Research Institute are obliged to make efforts in this regard. At present, the corona vaccine produced by these companies and institutions has either received a license or is in the final stages of clinical studies. Many review articles on these vaccines have been published in international journals, but just a few articles refer to the efforts made in Iran. Therefore, in the present article, an attempt has been made to classify and evaluate the structure, efficacy and side effects of these leading international and Iranian corona vaccines. Hence, the information published by the World Health Organization, the US Centers for Disease Control, pharmaceutical companies, reputable research centers and domestic and foreign organizations were employed.

Influenza virus is one of the most important causes of death due to respiratory diseases in poultry, which causes a lot of damage to the poultry industry worldwide every year. Hemagglutinin protein (HA) is one of the main factors in the pathogenesis of this virus. The aim of this research is cloning and expression of this gene in Sf9 cell using baculovirus.

After isolating of the H9N2 influenza virus genome, the HA gene was amplified by specific primers by RT-PCR and PCR methods and transferred to Bakmid using pFastBac Dual vector. The recombinant HA gene was transferred to the DH10Bac host cell. By transfecting Sf9 cell with recombinant bacmid, the expression of recombinant protein was examined by SDS-PAGE, western blotting and Bradford methods.

The protein obtained from recombinant Bakmid was evaluated using SDS PAGE and its purity was confirmed. The concentration of recombinant protein in the supernatant of Sf9 cells infected with recombinant virus was estimated to be 138µg / ml and confirmed by western blotting.

In the present study, the HA gene was successfully cloned on the PfastBacDual vector. With animal experiments, this protein could be used as a recombinant vaccine candida against influenza H9N2 virus.Key word: Influenza virus, Baculovirus, PfastBacDual vector, Recombinant vaccine

Gram-positive , Bacillus thuringiensis, produces crystals with insecticidal properties. rDNA sequence analysis is used to study the evolution and classification of organisms. The study was conducted on 16SrDNA sequence of five native isolates of Bacillus thuringiensis using the polymerase chain reaction.

Characteristics and phylogenetic relationships between five sequences of native isolates along with other isolates in the genebank and other species of the genus Bacillus were performed with Mesquite and leBIBIQBPP database.

The five native isolates were 92.06 to 99.93% similar to each other and 99.73% to 100% similar to other isolates of Bacillus thuringiensis. Phylogenetic trees showed Bt1019, Bt1020 and Bt1039 in the first group and Bt1001 and Bt1091 in the second group. Based on Bt1001 sequence analysis using leBIBIQBPP, the minimum distance with Bacillus frigoritolerans was obtained. The sequence of Bacillus anthracis was close to Bt 1019. The Bt 1020 sequence was closest to Bacillus cereus. In the case of Bt1039, in addition to Bacillus cereus, the lowest distance was observed with Bacillus marcorinectum. The Bt1091 sequence showed the most similarity with Bacillus frigoritolerans.

Protein crystals were observed in the native bacteria. Toxic crystals are produced only by Bacillus thuringiensis. BLAST program for 16SrDNA gene sequence in the native isolates also showed the most similarity to Bacillus thuringiensis isolates in the genebank. Moreover, the results predicted that the three native isolates including Bt1019, Bt1020 and Bt1039 could be toxic against lepidopteran and two isolates including Bt1001 and Bt1091 could be toxic against coleopteran.

bacteriocins are antimicrobial peptides produced by different bacteria and can be applied as a therapeutic agent. The aim of this study was to investigate the mode of action of broad-spectrum bacteriocin produced by a marine Bacillus strain Sh10, on Candida albicans ATCC 10231.

Cell viability assay, determination of UV-absorbing materials, K+, inorganic phosphate, ATP, and LIVE/DEAD cell viability assay as well as scanned and transmission electron microscopy were used to investigate the mode of action of bacteriocin.

The addition of 1 × MIC of bacteriocin to a cell suspension of C. albicans decreased the number of viable cells by about 4 log units over a period of 10 h. It displayed a fungicidal mode of action with a massive leakage of K+ ions, inorganic phosphates, ATP, and UV-absorbance materials, leading to cell lysis. In addition, the permeability of C. albicans treated cells to propidium iodide was also observed. The microscopic observations of treated cells indicated several modifications in cell morphology such as wrinkled surface, discontinuous and ruptured cell wall with concomitant lysis.

The data obtained in the current study demonstrated that the present bacteriocin interacted with the cytoplasmic membrane of C. albicans cells, resulting in pore formation, which allowed for the efflux of intracellular materials, ultimately leading to cell death.

Due to the widespread use of antimicrobials in veterinary medicine and the increase in livestock production, it seems that the risk of spreading antibiotic resistance in human societies is more related to animals and the veterinary field. In this study, antibiotic resistance and frequency of fimH, papC and sfa-foc virulence genes among Escherichia coli isolated from Caspian horse feces in Guilan were studied. In this cross- sectional study, E. coli isolates were isolated from the feces of 157 apparently healthy Caspian horses by culture method and biochemical tests. Resistance patterns against 17 different antibiotics were determined by disk diffusion method and frequency of virulence genes were assessed by PCR in isolates. In phenotypic assay of antibiotic resistance, the isolates showed the most resistance to streptomycin and sulfamethoxazole-trimetoprim antibiotics. Imipenem and gentamicin were the most effective antibiotics and 51.59 percent of isolates showed multi drug resistance pattern. The frequency of fimH, papC and sfa-foc virulence genes in isolates were 91%, 56.6% and 33.3%, respectively. Frequency of all of three investigated genes were significantly higher in MDR isolates (P< 0.05). The results of the present study indicate that Escherichia coli isolated from the feces of horses in Guilan has the potential to transmit antibiotic resistance and endanger public health.

Pseudomonas aeruginosa has several protein pumps with which it puts antibiotics out.This has led to the formation of multidrug resistance.The aim of this study was to investigate the effect of gold nanoparticles on the expression of mexA/B genes in multidrug resistant Pseudomonas aeruginosa strains.

In this cross-sectional descriptive study, 74 suspected samples of Pseudomonas genus were collected and phenotypic and genotypic tests were used to screen Pseudomonas aeruginosa.Then, anibiogram test using 11 antibiotics from different classes was performed by the use of CLSI 2020 standard tables and the disk diffusion method.The frequency of mexA/B genes was evaluated by polymerase chain reaction method and after determining the minimum inhibitory concentration of gold nanoparticles, the effect of gold nanoparticles on the expression of mexA/B genes was evaluated using SYBER Green-Real Time PCR technique.

In this study(67.57%) 50 isolates of Pseudomonas aeruginosa were identified.The highest and lowest levels of antibiotic resistance were related to azteronam(98%) and cefpime(26%).The prevalence of mexA/B genes was respectively mexA(74%), mexB(70%) and mexA/B(58%) and also 12% lacked both genes. Gold nanoparticles showed growth inhibitory effect at MIC≥50ppm and at 25 ppm concentration with ciprofloxacin, showed inhibitory effect on the expression of mexA/B genes.

The results of this study showed that gold nanoparticles can inhibit the expression of mexA and mexB genes in multidrug-resistant Pseudomonas aeruginosa.Due to the fact that gold nanoparticle does not have toxic effects on eukaryotic cells, it can be important in the treatment process of this group of bacteria.