فهرست مطالب dr. parviz owlia

Anaerobes are the causative agents of many wound infections. B. fragilis is the most prevalent endogenous anaerobic bacterium causes a wide range of diseases, including wound infections. This study aimed to assess the antibacterial effect of mouse AD-MSCs encapsulated in CF hydrogel scaffolds on B. fragilis wound infection in an animal model.

Stem cells were extracted from mouse adipose tissue and confirmed by surface markers using flow cytometry analysis. The possibility of differentiation of stem cells into osteoblast and adipocyte cells was also assessed. The extracted stem cells were encapsulated in the CF scaffold. B. fragilis wound infection was induced in rats, and then following 24 h, collagen and fibrin-encapsulated MSCs were applied to dress the wound. One week later, a standard colony count test monitored the bacterial load in the infected rats.

MSCs were characterized as positive for CD44, CD90, and CD105 markers and negative for CD34, which were able to differentiate into osteoblast and adipocyte cells. AD-MSCs encapsulated with collagen and fibrin scaffolds showed ameliorating effects on B. fragilis wound infection. Additionally, AD-MSCs with a collagen scaffold (54 CFU/g) indicated a greater effect on wound infection than AD-MSCs with a fibrin scaffold (97 CFU/g). The combined CF scaffold demonstrated the highest reduction in colony count (the bacteria load down to 29 CFU/g) in the wound infection.

  Our findings reveal that the use of collagen and fibrin scaffold in combination with mouse AD-MSCs is a promising alternative treatment for B. fragilis.

 Pseudomonas aeruginosa is an important ubiquitous and especially common pathogen in the hospital. Exotoxin A that encoded by exoA gene has a role in pathogenesis of this bacterium. Today, probiotics are widely used in the treatment and prevention of diseases. The present study aimed to study the Saccharomyces cerevisiae S3 effect on the expression of exoA gene.

 S. cerevisiae S3 supernatant and lysate were prepared. Subminimum inhibitory concentrations (sub-MIC) of extracts were used to P. aeruginosa PAO1. The level of exoA expression was measured with real-time PCR method.

Lysate extract had a reducing effect on toxin gene expression, but unlike lysate, supernatant had an increasing effect on gene expression.

 We demonstrated that S. cerevisiae S3 had an inhibitory effect on Exotoxin A virulence factor of P. aeruginosa. We suggest doing more experiments on the effect of S. cerevisiae on other virulence factors of P. aeruginosa and pathogens.

Biofilm production is an important virulence factor in Staphylococcus aureus. Most of the infections associated with biofilms of this bacterium are very difficult to treat using antibiotics. The present research studied the effects of the two probiotic Lactobacillus species L. casei and L. rhamnosus on S. aureus biofilm.

Cell‑free supernatant (CFS) extracts of L. casei ATCC 39392 and L. rhamnosus ATCC 7469 culture were prepared. The effects of sub‑minimum inhibitory concentrations of the CFS extracts on cell surface hydrophobicity (CSH), initial attachment, biofilm formation, and their ability in eradicating S. aureus ATCC 33591 biofilms were assessed. In addition, the effects of CFS extracts on expression of the genes involved in formation of S. aureus biofilms (cidA, hld, sarA, icaA, and icaR) were also evaluated through real‑time polymerase chain reaction.

CFSs of both Lactobacillus spp. significantly reduced CSH, initial attachment, and biofilm formation and eradicated the biofilms. The above findings were supported by scanning electron microscopy results. These two Lactobacillus CFSs significantly changed the expression of all studied biofilm‑related genes. Expression levels of cidA, hld, and icaR genes significantly increased by 4.4, 2.3, and 4.76 fold, respectively, but sarA and icaA genes were significantly downregulated by 3.12 and 2.3 fold.

The results indicated that CFS extracts of L. casei and L. rhamnosus had desirable antagonistic and anti‑biofilm effects against S. aureus. Consequently, carrying out further research enables us to prepare pharmaceuticals from these CFSs in order to prevent and treat infections caused by S. aureus biofilms.

Source tracking of antimicrobial resistance in Campylobacter is useful for control measures. In this study, Campylobacter-associated diarrhea and homology in antimicrobial resistance of humans and poultry meat isolates were investigated.

A total of 400 stools of patients and 100 poultry meat samples were analyzed. Susceptibility of the isolates was detected by disk diffusion, Etest, and agar dilution methods. Mismatch amplification mutation assay was used for the detection of mutations in the gyrA quinolone resistance determining region (QRDR).

Campylobacter spp., including C. jejuni, C. coli, and C. lari, were detected in 35% of the chicken meat and 6.75% of the stool samples, respectively. The QRDR mutation was detected in most of the stool and chicken meat samples. Although the frequency of resistance to tetracycline (53.5% and 62.8%), erythromycin (39.2% and 37.1%), and gentamicin (32.1% and 31.4%) was relatively similar, higher frequency of resistance to ciprofloxacin (51.4% vs 28.6%) and nalidixic acid (42.15% vs 28.6%) among the chicken meat, and ampicillin (50% and 17.1%) among the human stool was detected.

High percentage of poultry meat samples is contaminated with different Campylobacter species, which shows homology with the patients’ isolates in Tehran.

Methanotrophs are microorganisms that play an important role in reducing up to 15% of environmental CH4 concentration. These bacteria can oxidize methane to methanol. Methane is an atmosphere-polluting greenhouse gas with increasing atmospheric concentrations and is considered a serious threat to the environment and the sustenance of life on the planet. Possible unfavorable future weather and the extensive use of different types of pesticides necessitate the use of methanotrophic bacteria that are resistant to these conditions. The present study focused on the isolation and specific study of Methylocystis methanotrophic bacteria.

The bacterial strains were isolated from different environments such as wetlands, rivers, and paddy fields. The isolated strains were concentrated with Methane gas enriched cultures and purified by serial dilution-extinction, alternating liquid, and solid subcultures. Then, molecular identification was performed and a suitable culture medium was designed for Methylocystis strains in the name of Methylocystis Culture (MOC). Strains were cultured in MOC to evaluate their viability in different conditions by changing important parameters such as the temperature, pH, salinity, and drought. In addition, they were affected by pesticides. The methane gas reduction in the upper space of the culture medium of each strain, in accordance with the control samples, is considered as the methane oxidation of that strain.

Methane gas oxidation rate was determined in vitro for the cultures of several strains. The growth curve of the strains was plotted. According to the results, Methylocystis methanotrophs had high survivability in different conditions and were resistant to common pesticides, and consumed more than 75% of methane gas over a period of 14 days.

Methylocystis methanotrophic bacteria can greatly reduce the release of methane into the atmosphere and alter the fate of the atmosphere.

Antibiotics at sub-minimum inhibitory concentrations (sub-MIC) may alter bacterial virulence factors. The objective of this study was to investigate the effect of gentamicin at sub-MIC concentrations on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa.

The broth microdilution method was used to determine the MIC of gentamicin for three P. aeruginosa clinical isolates (P1-P3) and standard strains (PAO1 and 8821M). Alginate production and biofilm formation of the bacteria in the presence and absence of sub-MIC concentrations of gentamicin were measured using microtiter plate and carbazole assay, respectively. The real-time PCR method was used to determine the effect of gentamicin at sub-MIC concentrations on the expression level of genes involved in biofilm formation (pelA and pslA) and alginate production (algD and algU).

Gentamicin at sub-MIC concentrations significantly reduced alginate production, biofilm formation, and the expression of alginate and biofilm-encoding genes in clinical isolate P1. This inhibitory effect was also observed on the alginate production of 8821M strain and biofilm formation of PAO1strain. In clinical isolates, P2 and P3, alginate production, biofilm formation, and the expression of alginate and biofilm-encoding genes were significantly increased in exposure to sub-MIC concentrations of gentamicin.

This study showed that different phenotypic changes in clinical isolates and standard strains of P. aeruginosa in exposure to sub-MIC concentrations of gentamicin are associated with changes in the expression of virulence genes. Further researches are required to understand the mechanisms involved in regulating the expression of virulence genes after exposure to sub-MIC concentrations of antibiotics.

The ability of Pseudomonas aeruginosa to form biofilm has an important role in establishment of chronic phase of infections. Biofilm formation can be affected by antibiotics sub-MIC concentrations. The principal aim of the present study was to evaluate the effect of gentamicin at sub-MIC concentrations on biofilm formation in 100 Pseudomonas aeruginosa clinical isolates.

Determination of minimal inhibitory concentration of gentamicin for clinical isolates was done using micro broth dilution method. The amount of biofilm formation in the treated and untreated isolates with gentamicin sub-MIC (1/2&1/4MIC) concentrations was evaluated using microtitre plate assay. pelA and pslA genes were detected in clinical isolates by PCR method.

99% of clinical isolates were biofilm producer. Different changes in amountof biofilm formation were observed in the treated clinical isolates with sub-MIC concentrations of gentamicin. Two dominant changes were observed in 80% of clinical isolates. These concentrations had inhibitory effect on biofilm formation in 46.4% of isolates and caused a significant decrease in its amount. While in 31.3% of the isolates, the biofilm formation was significantly increased. The frequency of pelA and pslA genes among clinical isolates was 100%. 

gentamicin sub-MIC concentrations cause different changes on biofilm formation of Pseudomonas aeruginosa clinical isolates. Therefore, further studies are needed for discovering new treatment strategies and using sub-MIC concentrations of the antibiotic in prevention and treatment of Pseudomonas aeruginosa infections.

Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa.

  One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively.

Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were Multidrug-Resistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates.

High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.

Salmonella is one of the most important bacteria that causes gastroenteritis in humans and the spread of Salmonella strains with multidrug resistance is an acute global problem. Integrons are one of the most important factors responsible for transfering of drug resistance genes among Salmonella serotypes. In the present study, the frequency of class 1 and class 2 integrons as well as their relationship with drug resistance patterns in patients with gastrointestinal symptoms were investigated.

In this cross-sectional study, 400 human fecal samples with gastrointestinal symptoms were collected from 4 hospitals in Tehran. All the samples were analyzed by standard method for microbial culture and the results were confirmed by biochemical and PCR tests. Antimicrobial susceptibility testing was performed by disk diffusion method. After DNA extraction, the presence of class 1 and 2 integrons was investigated by PCR. Statistical analysis for detection of correlation between the presence of integrons and resistance patterns was done using SPSS software and Fisherʼs exact test.

The results showed that Salmonella was present in 5.5% (22.400) of the stool specimens. The prevalence rates of class 1 and 2 integrons for human stool specimens were 40.9% (9/22) and 27.2% (6/22), respectively. MDR phenotype was detected in 4.5% (1.22) of the Salmonella isolates from patients with gastroenteritis.

In this study, high levels of integrons 1 and 2 were observed in the patients' Salmonella isolates with gastroenteritis. The observed relationship between drug resistance patterns and the integrons indicated a possible increased risk of drug resistance genes in Salmonella isolates with human gastroenteritis.

Pseudomonas aeruginosa is considered as the most severe cause of infections in burn patients and pneumonia infections. To study the protective effects of recombinant protein vaccine harboring the PcrV of P. aeruginosa in the mouse model of burn and respiratory infections. Recombinant protein vaccine harboring the PcrV was expressed in the E. coli BL-21 strain. Mice were immunized with the purified recombinant protein, and the antibody titer was measured in the sera obtained from the immunized mice. Immunized and control mice werechallenged by active and passive immunization. The microbial counts in the lung, skin, liver, spleen, and kidney were compared with the control mice. Bioinformatics analysis indicated that the PcrV protein was conserved in 1552 clinical and environmental isolates. Also, the isoelectric point (pI), molecular weight, and Grand Average of Hydropathy (GRAVY) score were analyzed. Mice were injected with recombinant protein, and serum from immunized mice reacted strongly with recombinant antigen at a dilution of 1:64000. The survival rate of mice infected with 5xLD50 of the P. aeruginosa increased significantly up to 75% in the standard strains (PAO1 and PAK), and the number of bacteria, especially in the internal organs (kidney, spleen, and liver) significantly reduced compared to the mice immunized with placebo. Our results demonstrated that the PcrV protein could be an effective candidate vaccine for the generation of antibody response against P. aeruginosa infection.

Campylobacter species are among foodborne pathogens that are known as the main cause of inflammatory diarrhea in humans. In this cross-sectional study, we investigated the prevalence of Campylobacter spp. and their drug resistance status in fecal samples of patients with community-acquired gastroenteritis in Tehran.

In this survey, infection with Campylobacter spp. was evaluated in 400 stool samples of patients with diarrhea. Accordingly, microscopic examination to show the presence of exudative diarrhea, rejection of fungi and parasitic infections, enrichment and culture in a specific medium under microaerophilic conditions, determination of biochemical identity, and molecular confirmation at genus and species levels for C. jejuni, C. coli, C. lari, and C. upsaliensis were performed. Antibiotic resistance patterns were determined by E-test and disk diffusion methods, and the presence of the dominant gyrA gene mutations in the quinolone-resistance domain of C. jejuni isolates was determined by using Mismatch Amplification Mutation Assay-polymerase chain reaction (MAMA-PCR)[1].

A total of 28 strains of Campylobacter were isolated from the samples obtained from the patients with diarrhea. The most common species were C. jejuni (6%), C. coli (0.5%), C. lari (0.25%), and other unknown species (0.25%). The highest antibiotic resistance rate was observed against tetracycline and ampicillin (53.5% and 50%, respectively), and the lowest rate was detected for nalidixic acid and ciprofloxacin (28.5% and 28.5%). Multiple drug resistance (MDR) phenotype was detected among 51.8% of the strains.

Results of this study indicated C. jejuni as the main Campylobacter species responsible for community-acquired diarrhea among the studied patients. The high rate of resistance to antibiotics and MDR phenotype in these strains compared with other countries is considered a risk, especially in the treatment of invasive infections.

One of the major issues in food hygiene and safety is the emergence of antibiotic-resistant bacteria. Pathogens as well as biofilm formation can play a role in increasing bacterial resistance. In this study, biofilm formation in Salmonella isolates from chicken, drug resistance and drug resistance pattern were investigated.

In this study, 75 samples of chicken infected with Salmonella bacteria were studied. The rate of biofilm formation was assessed by microtiter plate method. Drug resistance and evaluation of drug resistance pattern were also evaluated.

The results showed that in 92% (69/75) of the samples Salmonella biofilm were formed, among which the moderate biofilm with 65.2% had the highest biofilm production. Concurrent resistance to 2 classes of antibiotics (2DR) with 31.8% (22/69) was the most common type of multidrug resistance (MDR) among the biofilm-forming isolates. Resistance to imipenem, ceftriaxone and cefotaxime was observed in only 1 biofilm formation sample.

In this study, high biofilm formation was observed in Salmonella contaminated chicken meat samples. The high rate of antibiotic resistance in biofilm constituents is due to the increasing attention to hygienic aspects of non-transmission of food contamination to humans.

Klebsiella pneumoniae is one of the most important bacteria that cause nosocomial infections. This opportunistic pathogen has a high potential for antibiotic resistance and can generate a thick layer of biofilm. Nowadays, antibiotic resistant strains are emerging and widely spreading worldwide. Thus, it is necessary to combat drug-resistant strains through the use of novel drugs (such as medicinal plants).

This study aimed to evaluate the in vitro antibacterial activity of Satureja rechingeri Jamzad, S. khuzestanica Jamzad, S. bachtiarica Bunge, and S. mutica Fisch. & C.A.Mey. essential oils against K. pneumonia ATCC 700603.

For evaluation of the minimal inhibitory concentration (MIC) of essential oils, broth microdilution method was used. The microtiter plate assay method was used for the assessment of anti-biofilm activities of sub-MIC value of essential oils. Colorimetric and Iodometric assays were used for determination of urease and beta-lactamase activity.

According to data collected, the MIC value of essential oils was 4096 µg/mL. sub-MIC value of essential oils inhibited biofilm formation and urease activity of K. pneumoniae. However, S. khuzestanica had more activity. None of the essential oils caused a significant decrease in beta-lactamase activity of K. pneumoniae.

Based on our analysis S. khuzestanica had a good antibacterial, anti-biofilm activities and urease inhibitory effects against K. pneumoniae, but additional studies are required to investigate the exact mechanisms of the antibacterial action and functions of this phytocompound.

 Shiga-toxigenic Escherichia coli (STEC) is an important foodborne pathogen and considered a worldwide problem. The infection can cause severe illnesses, including hemolytic uremic syndrome. Traditional methods for STEC detection are currently not done in clinical laboratories due to the cost and related long turnaround time, which necessitates the development of quick and reliable alternative detection methods.

 In this study, the application of PCR and real-time PCR methods for rapid detection of STEC in DNA extracts of stool samples was investigated.

 A synthetic control DNA vector, containing target genes of stx1, stx2, EhxA, and eae, was designed to evaluate the validity of these methods. Moreover, efficiency of primers targeting the genes, limit of detection, repeatability, sensitivity, and specificity of real-time PCR assay was compared with PCR results.

 Repeatability of real-time PCR assay showed percent coefficient of variation of 3.3% - 16.1% and sensitivity of 66% to 100%. Efficiency of all the primers was 100% with a detection limit of 103 copies of DNA per reaction for both of the two assays. Comparison of the results showed that real-time PCR was more sensitive than conventional PCR. The chimeric vector interfered with template DNA when it was used as an internal control in PCR and real-time PCR assays; however, its application as external control was approved for detection of all targeted genes in STEC.

 These results confirmed application of the chimeric vector as an external control in detection of STEC by both PCR and real-time PCR assays, but its usage as an internal control was not approved in this study.

Pathogenic species of Campylobacter, in addition to diarrhea and gastrointestinal diseases, could cause debilitating auto-immune and chronic diseases in humans. Investigation of the existence of this bacterium in food sources and clinical samples, and detection of antibiotic resistance could be helpful in the control of its spread and treatment procedures. The aim of this study was to evaluate the frequency and antibiotic resistance of Campylobacter isolates isolated from poultry meat.

In this study, a total of 100 poultry meat samples were collected from 22 districts of Tehran from July 2018 until March 2019. Accordingly, standard enrichment of the collected samples and their culture in selective medium was done. The isolates were characterized biochemically and by polymerase chain reaction for genus and species specific primers for C. jejuni, C. coli, C. upsaliensis, and C. lari. Antimicrobial susceptibility of the isolates to 7 antibiotics were done using E-test and disk diffusion methods. Moreover, resistance to three or greater classes of antibiotics was determined as multiple drug resistance phenotype (MDR) and the results were statistically analyzed using SPSS16 software.

Campylobacter was isolated from 35% of the poultry meat samples. C. jejuni (23%), C. coli (1%), and C. lari (1%) were among the Campylobacter isolates from these samples. Highest resistance phenotype and the lowest ones were detected against tetracycline (62.8%), and ampicillin and clindamycin (17.1%, each one), respectively. The MDR phenotype was detected among 42.8% of the isolates.

Our results showed high level of contamination with Campylobacter in the poultry meat samples which proposed increased risk of the infection with MDR strains among the consumers in Tehran. Further studies on human clinical samples could better determine this correlation.

Iron and zinc are two essential micro-nutrients for plant growth and development. Therefore, isolation of siderophores-producing and zinc-solubilizing rhizobacteria involved in bio-availability of these elements is of great interest.

In this study, soil samples collected from slightly alkaline soil types were screened for high levels of siderophore secretion and zinc solubilization.

Among positive colonies, three isolates, named F21A, F37 and F38, were able to secrete siderophore at high levels, ranged between 200 and 300 µM/liter. A close association was observed between siderophore production capability and growth rate as an indicator of active metabolism. Siderophore production was closely correlated with the level of zinc ion released into the medium as well. All three siderophore producing isolates were able to withstand temperature as high as 37°C, high concentration of NaCl (up to 2.5%) and a wide range of initial pH from 6 to 9 while hydrolyzing Zn compounds actively. One of the isolates, F21A, tolerated the presence of 200 mgl-1 of zinc. Biochemical and molecular characteristics are indicative that these isolates are Pseudomonas japonica. As experienced in a greenhouse experiment, inoculation with the F21A and F37 isolates significantly increase the plants height, fresh and dry weight of corn with compared to control.

These findings demonstrated that the potential of P. japonica strains as plants growth promoting rhizobacteria (PGPR) in iron and zinc deficient soils.

Salmonella is one of the leading causes of foodborne illnesses worldwide which has become an important issue today due to the increasing drug resistance. This study was aimed to detect the frequency and diversity of Salmonella serogroups and drug resistance patterns among poultry meat samples distributed in Tehran, Iran.
 
In this cross-sectional study, 100 samples of poultry meat were prepared from authorized distributors of meat products from 22 districts of Tehran. All samples were analyzed by standard method and characterization of the isolates were done using biochemical, polymerase chain reaction, and serogrouping methods. Antibiogram was done using disk diffusion method.
 
The results showed that Salmonella was present in 75% (75/100) of the chicken meat samples. Chicken meat isolates were predominantly belonged to serogroup C (88%, 66/75), while other isolates belonged to serogroup B (2.6%, 2/75), serogroup D (5.3%, 4/75), and non-group A–D Salmonella isolates (5.3%, 4.75). While resistance to tetracycline (59%) was the most common resistance phenotype in these isolates, concurrent resistance to 3 classes of antibiotics (3DR) was the most common type of multidrug resistance (MDR) phenotype among them.
 
In this study, high rate of contamination with Salmonella was observed in the chicken meat samples. Dominance of antibiotic resistance in these isolates showed their possible risk for transmission of resistance gene markers to the human gut microbiota through food chain.

Staphylococcus aureus, as an opportunistic pathogen, is the cause of a variety of diseases from mild skin infections to severe invasive infections and food poisoning. Increasing antibiotic resistance in S. aureus isolates has become a major threat to public health. The use of compounds produced by probiotics can be a solution to this problem. Thus, the purpose of this study was to investigate the effect of Saccharomyces cerevisiae on some virulence factors (biofilm, α-hemolysin, and enterotoxin A) of S. aureus. Supernatant and lysate extracts were prepared from S. cerevisiae S3 culture. Sub-MIC concentrations of both extracts were separately applied to S. aureus ATCC 29213 (methicillin-sensitive S. aureus; MSSA) and S. aureus ATCC 33591 (methicillin-resistant S. aureus; MRSA) strains. Biofilm formation of these strains was measured by microtiter plate assay and expression level of α-hemolysin and enterotoxin A genes (hla and sea, respectively) using real-time PCR technique. The supernatant extract has reduced both biofilm formation and expression of sea and hla genes, while lysate extract had only anti-biofilm effects. The MRSA strain showed more susceptibility to yeast extracts than MSSA strain in all tests.


The present study exhibited favorable antagonistic effects of S. cerevisiae S3, as a probiotic yeast, on MSSA and MRSA strains. Based on the findings of this study, the compounds produced by this yeast can be used to control S. aureus infections; however, further similar studies should be conducted to confirm the findings of the present study.

A few studies have been done on the molecular analysis of Iranian influenza A isolates M gene. In 2014, nasal swabs collected from outpatients with clinical symptoms in the hospital clinics of Tehran, Iran were subjected for influenza detection and subtyping using Real-Time RT-PCR. Sequence and phylogenetic analysis performed on four randomly selected isolates from each subtype (H1N1 and H3N2) using neighbor-joining method. Phylogenetic dendrograms drawn based on M nucleotide sequence of H1N1 isolates showed close relatedness with Omanian isolates while the most isolates of H3N2 have clustered with Kuwait isolates and isolates from outside of geographical location. Amino acid sequence analysis showed S31N substitution in all isolates rendering the virus resistant to adamantanes. This study determined the sequence identity and phylogenetic relatedness of M gene sequence got from Iranian influenza A isolates to elucidate the modality of relationship of this gene in comparison with its counterparts from other regions.

The majority of studies on soil Aspergillus concern the isolation and characterization of the antimicrobial compounds produced by this organism. Our previous studies indicated an isolated Aspergillus strain soil to be of interest, and this subject is further investigated here. Soil samples of various locations in Iran were collected. Extract from Aspergillus sp. culture was obtained using ethyl acetate fractionation. Antimicrobial activity testing was performed using broth microdilution assay against Escherichia coli, Candida albicans, and Staphylococcus aureus microorganisms. One metabolite PA3-d10 was isolated from these active extracts and identified using thin layer chromatography, preparative thin-layer chromatography, HPLC, 1HNMR (proton nuclear magnetic resonance), 2D NMR, and LC-MS (liquid chromatography-mass spectrometry). According to morphological and biochemical properties as well as ITS rDNA sequencing, we identified an isolate of Aspergillus flavus. The ethyl acetate fraction of the fermentation medium containing membrane active metabolites showed antimicrobial effects against different bacterial and yeast indicator strains. One metabolite from these active extracts was finally identified. Membrane active fraction produced by Aspergillus strain in this research demonstrated antimicrobial activities against bacteria and yeast strains. Therefore, this metabolite can be considered as a potential antimicrobial membrane active agent.

Bordetella pertussis is a Gram-negative coccobacillus bacterium which is the causative agent of whooping cough. In recent years, the number of whooping cough cases has been rised. This bacterium has important virulence factors such as fimbriae and pertactin. In this study, polymorphism of Serotype 2 and 3 fimbriae genes and 2 Regions of pertactin gene were surveyed.

Totally, 20 B. pertussis clinical isolates were tested. DNA was extracted using the kit. Serotypes 2 and 3 fimbriae genes and pertactin Region 1 and 2 were identified using PCR method; finally, 13 samples were randomly sequenced.

No mutation was observed in the pertactin Region 2. In relation to the region1 of pertactin, 77% and 23% of the strains had prn2 and prn1 alleles, respectively. In relation to fim2 gene, 70% and 30% of the strains had fim2-2 and fim2-1 alleles, respectively. Also, in relation to fim3 gene, 70% and 30% of the strains carried fim3B and fim3A alleles, respectively.

In general, the present study results were similar to those of the previous studies conducted in Iran, but there were some differences in fim2 gene polymorphism so that the dominant allele changed from fim2-1 to fim2-2. Considering the fact that vaccine strains of Bp134 and Bp509 carry fim3A allele, which is different from the dominant circulating allele (fim3B), it is suggested that strains more similar to the dominant circulating strains should be used in designing vaccines.

Probiotics are useful microorganisms for health of communities. Saccharomyces cerevisiae is one of the effective microorganisms for treating of functional and gastrointestinal diseases in order to control pathogens. Enterohemorrahgic Escherichia coli (EHEC) and Enterotoxogenic (ETEC) are common pathogenic strains in all the world. The aim of this study was to evaluate the inhibitory effect of S. cerevisiae probiotic yeast on the growth of ETEC and EHEC. For preparation of the supernatant extract, the yeast suspension was centrifuged, and then, the supernatant was filtered. Extraction with ethyl acetate was performed in three hours. For preparation of lysate, the precipitate was washed and centrifuged. The supernatant was removed and sterilize distilled water was added. Cell lysis was performed by sonication and the liquid was centrifuged and filtered. Then, the MIC and MBC were determined by micro dilution method. The concentration range was 16-8192 μg/ml. The MIC and MBC of the supernatant against both ETEC and EHEC were 4096 μg/ml and 8192 μg/ml, respectively. Lysate in any of the concentrations showed no inhibitory effects on strains. The supernatant of S. cerevisiae has an inhibitory effect on growth of ETEC and EHEC. The lysate, probably due to the richness of the nutrients required for bacterial growth and not containing antibacterial compound, did not lead to such a repressive effect.

Pseudomonas aeruginosa is a potent pathogen for humans using multiple virulence factors. The purpose of this study was to investigate the effect of Saccharomyces cerevisiae lysates and supernatants on biofilm, alginate factors. First, the supernatant extract and lysate were prepared from the native strain of Saccharomyces cerevisiae and turned into dry powder. Then, supernatant and lysate extracts were admixed with Pseudomonas aeruginosa strain PAO1 and strain M 8821, respectively, and biofilm in the strain PAO1 and alginate in strain 8821 M by Colorimetric method is measured by reading Optical Density(OD) also mention to the wave length. Supernatant with MIC concentration of 1/2 in both experiments and all concentrations of lysates in biofilm test and the highest concentration of lysates in alginate test were used. Supernatant of Saccharomyces cerevisiae at a concentration of 1 / 2MIC (0.512 mg / ml) with P <0.05 significantly reduced the production of alginate in Pseudomonas aeruginosa 8821 M strain, but did not affect biofilm in Pseudomonas aeruginosa PAO1 strain respectively, with all concentrations and the highest concentration (8.192 mg / ml) with P <0.05 significantly reduced the production of biofilms in Pseudomonas aeruginosa strain PAO1 and alginate in Pseudomonas aeruginosa 8821 M strain. Saccharomyces cerevisiae is one of the options that probiotic studies can examine its effects on virulence pathogens, but requires the ultimate goal of producing probiotic drugs.

Adhesion to host cells is an important and critical feature of Acinetobacter baumannii pathogenesis. OmpA, ABAYE1319-CsuA/b, and ABAYE2132 are highly prevalent and conserved fimbrial proteins; ABAYE1859 and ABAYE0304 fimbrial antigens are the factors described as novel vaccine candidates against multidrug-resistant (MDR) A. baumannii.
The current study aimed at investigating the significance of A. baumannii fimbrial and outer membrane proteins A (OmpA) in adherence to human epithelial cells. Antibiotic resistance was determined by the broth microdilution method. Phenotypic identification of isolates producing ESBL (extended-spectrum beta-lactamase) was conducted using double-disc synergy test (DDST). The virulence factors were detected by the polymerase chain reaction (PCR) in 100 non duplicate clinical isolates of A. baumannii; 18 clinical isolates were selected for adhesion assay based on antibiotic resistance and PCR results.
The current study results showed that ABAYE2132, ABAYE0304, and ABAYE1319- CsuA/B had significant correlation with cell adhesion (P ≤ 0.05). There was no significant correlation between cell adhesion and ABAYE1859 (P ≥ 0.05). ABAYE2132 was the most effective factor in cell adhesion. It was also observed that cell adhesion rate reduced with the increase of fimbrial proteins.
The current study findings suggested that different products and structures of A. baumannii, most still unknown, play a pivotal role in pathogen-biotic reactions. Better exposure of some non-pili adhesins or other biofilm forming factors could be a reason for this phenomenon.

Selenium (Se) as a vital trace element has many biological activities such as anti-inflammation and anti-oxidation. Selenomethionine as an organic selenium plays a vital role in the response to oxidative stress. At present, Saccharomyces cerevisiae is one of the best microorganisms that has the ability to accumulate selenium. Production of Seleno-yeast was done by growing Saccharomyces cerevisiae in the presence of water soluble selenium salt (Na2SeO3) as a part of the medium. The yield of selenium biotransformation and yeast biomass can be improved by optimizing the process conditions in two steps. First, the effects of several culture parameters (culture conditions and culture media) were studied using the Plackett-Burman design. After that, determining the optimum levels of the effective parameters was performed by Box-Behnken response surface methodology. Optimization of the conditions was performed with the aim of simultaneously optimizing the biomass and selenium biotransformation. In this investigation, the effect of the eleven culture parameters was studied with Plackett-Burman design. Then, four significant culture parameters such as glucose concentration, aeration, selenium concentration, and temperature were optimized with Box-Behnken response surface methodology.