abolfazl fateh

Acinetobacter baumannii is notorious for its high resistance levels, and the development of clinically effective antimicrobial agents is an urgent medical challenge. Single-chain variable fragments (scFvs) that exhibit antibacterial properties against challenging pathogens, such as Pseudomonas aeruginosa and Staphylococcus aureus, have the potential to improve therapeutic strategies significantly. Their unique ability to function independently of the host immune system makes scFvs a highly promising option for effective treatment. In our previous studies, we identified two human scFvs (EB211 and EB279) that showed direct growth inhibition activity against A. baumannii strains in vitro and therapeutic effectiveness in immunocompromised mice with pneumonia caused by an extensively drug-resistant A. baumannii strain. In the present study, we endeavored to demonstrate how EB211 and EB279 could inhibit the growth of A. baumannii.

A. baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa strains were individually incubated with the scFv in the presence of a high concentration of magnesium (MgSO4; 20 mM). Epitope mapping and immunoblotting were conducted to identify A. baumannii proteins likely bound by EB211 and EB279. 

It was found that EB211 and EB279, similar to colistin sulfate, lost their activity in the presence of magnesium. Moreover, immunoblotting revealed that EB211 and EB279 might bind the OprD family outer membrane porin and TonB family C-terminal domain protein, respectively.

EB211 and EB279 elicit direct growth inhibitory activity against A. baumannii without needing immune cells or complements, which could be helpful for immunocompromised patients.

TB infection is one of the most challengeable epidemiological issues. Complex interactions between microbiota and TB infection have been demonstrated. Alteration in microbial population during TB infection may act as a useful biomarker. The present study examined the microbiota patterns of blood and sputum samples collected from Afghan immigrants and Iranian patients with active TB.

Sixty active pulmonary TB patients were enrolled in the study. Blood and sputum samples were collected. To detect phylum bacterial composition in the blood and sputum samples, bacterial 16S rRNA quantification by Real-Time qPCR was performed.

A significant decrease in Bacteroidetes in Iranian sputum and blood samples of Afghan immigrants and Iranian TB active subjects were seen. While, sputum samples of Afghan immigrants showed no significant differences in Bacteroidetes abundance among TB active and control. Firmicutes were also presented no significant difference between sputum samples of the two races. Actinobacteria showed a significant increase in Iranian and Afghan sputum samples while this phylum showed no significant abundance in Iranian and Afghan TB positive blood samples. Proteobacteria also showed an increase in sputum and blood samples of the two races.

An imbalance in Bacteroidetes and Firmicutes abundance may cause an alteration in the microbiota compo- sition, resulting in dysregulated immune responses and resulting in the augmentation of opportunistic pathogens during TB infection, notably Proteobacteria and Actinobacteria. Evaluation of human microbiota under different conditions of TB infection can be critical to a deeper understanding of the disease control.

Tuberculosis (TB) has been a major health issue throughout history. As part of TB infection, host-Mycobacterium tuberculosis (Mtb) interactions are important. Through immune pathology and cell death control processes, Mtb infection facilitates intracellular growth. The relationship between apoptosis and inflammation in Mtb infection remains unclear. In this study, the levels of related apoptosis and inflammatory genes were assessed in A549 cells infected with a variety of Mtb strains.

Mtb isolates with different phenotypes (sensitive, INHR, RifR, MDR, and XDR) were collected from the Pasteur Institute of Iran, during this study. Whole genome sequencing was previously performed on all strains, and the Beijing genotype was selected as sensitive. Also, for other resistant strains, the New-1 genotype was available and isolated for genotype comparison. A549 lung carcinoma cells were also grown and infected with selected Mtb strains. Genes involved in inflammation and apoptosis were detected using reverse transcription-PCR (RT-PCR).

All sensitive strains and resistant strains were found to significantly up-regulate anti-apoptotic (bcl2 and rb1), chemokine (IL-8 and MCP-1), and pro-inflammatory cytokine (TNF-α and IFN-γ) expression, while significant down-regulation was observed after 24 and 48 hr of infection in anti-inflammatory genes (IL-10) and pro-apoptotic genes (bad and bax). Besides resistance strains, Mtb genotypes also affected gene expression. The Beijing genotype (sensitive isolate) influences inflammatory and apoptotic genes more sharply than the New-1 genotype (INHR, RifR, MDR, and XDR).

Gene expression differences related to apoptosis and inflammation examined in the current study may be attributed to genotypes rather than resistance status since the expression of most genes has been observed to be lower in resistant strains (INHR, RifR, MDR, and XDR belonging to the New-1 genotype) compared to sensitive strains (Beijing genotype).

Extracellular vesicles (EVs) are nano- to micron-sized vesicles with the ability to transport bioactive cargos. All types of cells have the ability to release EVs, which have been demonstrated to be involved in a number of essential cell functions. There are various methods for isolating EVs, each with advantages and disadvantages. The purpose of this study was to invistigate at the non-ultra centrifugation method and ultra-centrifugation method for isolating EVs.

Clostridium perfringens ATCC13124 was used in this experimental study. Following culture, EVs were extracted using two methods Non-Ultra method and Ultra-method. To examine chemical characteristics, the EV protein concentration was measured using a NanoDrop device, and the EV protein pattern was identified using SDS-PAGE. Transmission electron microscopy (TEM) was utilized to examine the EVs' physical properties.

Our results showed that the EVs isolated by the Ultra-method had a higher protein content compared to the Non-Ultra method (3.17 and 1.46 mg/ml, respectively).The Ultra-method isolated more and larger EVs compared to the Non-Ultra method. Also, protein patterns of the EVs by SDS-PAGE method were similar in both methods.

The present study showed that the Ultra-method can be a more efficient and cost-effective way for isolation EVs from Clostridium perfringens than the Non-Ultra method.

Tuberculosis, caused by Mycobacterium tuberculosis, is one of the most common infectious diseases worldwide. Epidemiological studies of M. tuberculosis drug resistance are critical for improving patient treatment approaches and controlling the spread of tuberculosis. The present study aimed to determine antibiotic resistance among M. tuberculosis clinical isolates using the Microplate Alamar Blue Assay (MABA).

In this descriptive cross-sectional study, 25 M. tuberculosis isolates from clinical samples were identified and confirmed using standard microbiological and biochemical tests. Then, the MIC for the antibiotics Bedaquiline, isoniazid, rifampin, ethambutol, ofloxacin, moxifloxacin, capreomycin, and streptomycin was determined using the MABA method. The results were analyzed using SPSS version 16 software.

Among the 25 investigated isolates, the frequencies for MDR, Pre-XDR, and XDR isolates were 20%, 8%, and 32%, respectively. The highest rate of drug resistance was to isoniazid (80%), rifampicin, and ethambutol (76%), and the highest rate of sensitivity was to moxifloxacin (68%). The frequency of isoniazid mono-resistance and rifampicin mono-resistance was 5 cases (50%) and 4 cases (40%), respectively.

Our study revealed an alarming rate of MDR and XDR M. tuberculosis strains, indicating that current first-line treatments may be ineffective for a significant number of patients. The bedaquiline resistance among the isolates with no history of previous exposure to this drug suggests unexplored resistance mechanisms. Molecular techniques to accurately identify these mechanisms may contribute to developing more effective treatment strategies to combat drug-resistant tuberculosis.

Tuberculosis (TB) caused by the bacterium Mycobacterium tuberculosis remains a critical global public health concern due to the high morbidity and mortality rates. Mutation in atpE and Rv0678 genes contributes to drug resistance in M. tuberculosis. This study investigates the antibiotic resistance patterns and mutations in atpE and Rv0678 genes in 22 M. tuberculosis clinical isolates.

Drug susceptibility testing (DST) for rifampin, isoniazid, streptomycin, capreomycin, ofloxacin, kanamycin, and ethambutol was conducted using the proportional method. This was followed by determining the minimum inhibitory concentration (MIC) for bedaquiline (BDQ) via the microplate Alamar blue assay (MABA). Genomic regions encompassing atpE and Rv0678 genes were amplified and sequenced for mutation analysis. Data analysis was performed using SPSS software to interpret mutation patterns concerning drug susceptibility profiles.

Of 22 isolates, 5 (27.8%) were extensively drug-resistant tuberculosis (XDR-TB), and 13 (72.2%) were multi-drug resistant tuberculosis (MDR-TB). Resistance rates to kanamycin, ofloxacin, capreomycin, and streptomycin were 40.6%, 46.3%, 85%, and 74.6%, respectively. Additionally, phenotypic resistance to bedaquiline was observed in 12 (54.5%) isolates. Sequencing revealed no resistance-conferring mutations in the atpE or Rv0678 genes among the isolates.

Our findings showed substantial resistance to first- and second-line drugs in M. tuberculosis clinical isolates. This highlights the necessity for ongoing, comprehensive studies to elucidate the evolving drug resistance patterns and understand the underlying mechanisms in clinical isolates.

The role of microRNAs (miRNAs) in tuberculosis infection is well established. As microR- NAs are able to change expression profiles according to different conditions, they can be useful biomarkers. Iranians and Afghans with tuberculosis were studied for three immune-related miRNAs (miR-let-7f, miR-125a, and miR-125b).

A total of 60 Iranian and Afghan patients with active pulmonary TB were enrolled in the Pulmo- nary Department of the Pasteur Institute of Iran. Serum and sputum samples were collected simultaneously from all partici- pants. A Real-time PCR was conducted to detect differentially expressed miRNAs.

Iranian (P<0.0001) and Afghan (P<0.0001) serum samples and Afghan (P<0.0001) sputum samples overexpressed miR-125a, whereas Iranian sputum samples showed downregulation (P=0.0039). In both Iranian (P<0.0001; P=0.0007) and Afghan (P<0.0001; P<0.0001) serum and sputum samples, miR-125b was overexpressed. Furthermore, miR-let-7f down- regulation was observed in serum and sputum samples (P<0.0001), whereas Iranian sputum samples had no statistically significant differences (P=0.348).

Overexpression of miR-125a and miR-125b has been detected in Iranian and Afghan samples. In both races, miR-let-7f downregulation has been confirmed. Identification of miRNA profiles under different conditions opens the door to evaluating potential new biomarkers for diagnosis, disease monitoring, and therapeutic markers in TB infection.

The inability of the host immune system to defeat Staphylococcus aureus is due to various secreted virulent factors such as leukocidins, superantigens, and hemolysins, which interrupt the function of immune components. Alpha-hemolysin is one of the most studied cytolysins due to its pronounced effect on developing staphylococcal infections. Alpha-hemolysin-neutralizing antibodies are among the best candidates for blocking the toxin activity and preventing S. aureus pathogenesis. 

A human single-chain variable fragment (scFv) phage display library was biopanned against alpha-hemolysin. The selected phage clones were assessed based on their binding ability to alpha-hemolysin. The binding specificity and affinity of two scFvs (designated SP192 and SP220) to alpha-hemolysin were determined by enzyme-linked immunosorbent assay. Furthermore, the neutralizing activity of SP192 and SP220 was examined by concurrent incubation of rabbit red blood cells (RBCs) with alpha-hemolysin and scFvs.

SP192 and SP220 showed significant binding to alpha-hemolysin compared with the control proteins, including bovine serum albumin, human adiponectin, and toxic shock syndrome toxin-1. Besides, both scFvs showed high-affinity binding to alpha-hemolysin in the nanomolar range (Kaff: 0.9 and 0.7 nM-1, respectively), leading to marked inhibition of alpha-hemolysin-mediated lysis of rabbit RBCs (73% and 84% inhibition; respectively). 

SP192 and SP220 scFvs can potentially be used as alpha-hemolysin-neutralizing agents in conjunction with conventional antibiotics to combat S. aureus infections.

The high resistance rate of Acinetobacter baumannii and the limited number of available antibiotics have prompted a worldwide effort to develop effective antimicrobial agents. Accordingly, identifying single-chain variable fragment antibodies (scFvs), capable of exerting direct antibacterial activity in an immune system-independent manner, may be making immunocompromised patients more susceptible to A. baumannii infections.

To isolate bactericidal scFvs targeting A. baumannii, we panned a large human scFv phage display library against whole-cell extensively drug-resistant (XDR) A. baumannii strains grown as biofilm or cultured with human blood or human peripheral blood mononuclear cells plus plasma. The binding of scFv-phages to A. baumannii was assessed by the dot-blot assay. Soluble scFvs, derived from the selected phages, were assessed based on their ability to bind and inhibit the growth of A. baumannii. 

Five phage clones showed the highest reactivity toward A. baumannii. Among five soluble scFvs, derived from positive phage clones, two scFvs, EB211 and EB279, had high expression yields and displayed strong binding to A. baumannii compared with the controls. Moreover, XDR A. baumannii strains treated with positively-charged scFvs, including EB211, EB279, or a cocktail of EB211 and EB279 (200 µg/ml), displayed lower viability (approximately 50%, 78%, and 40% viability, respectively) compared with PBS-treated bacteria.

These results suggest that combining last-resort antibiotics with bactericidal scFvs could provide promising outcomes in immunocompromised individuals with A. baumannii infections.

Autophagy induction has been shown to differ in magnitude depending on the mycobacterial species. However, few studies have investigated the specific autophagic capacity of different Mycobacterium tuberculosis (Mtb) strains in alveolar epithelial cells (ATs). This study aimed to elucidate the host autophagic response to different Mtb strains in ATs responsible for TB in the capital of Iran, Tehran.  

A549 cells were infected with three different Mtb clinical isolates (Beijing, NEW1, and CAS1/Delhi) and the reference strain H37Rv. Following RNA extraction, the expression of eight ATG genes, four mycobacterial genes, and three miRNAs was evaluated using quantitative RT-PCR.  

The results revealed that all four strains influenced the autophagy pathway in various ways at different magnitudes. The Beijing and H37Rv strains could inhibit autophagosome formation, whereas the CAS and NEW1 strains induced autophagosome formation. The expression of genes involved in the fusion of autophagosomes to lysosomes (LAMP1) indicated that all the studied strains impaired the autophagolysosomal fusion; this result is not unexpected as Mtb can block the autophagolysomal fusion. In addition, the Beijing and H37RV strains prevented the formation of autophagic vacuoles, besides mycobacterial targeting of lysosomes and protease activity.

This preliminary study improved our understanding of how Mtb manages to overcome the host immune system, such as autophagy, and evaluated the genes used by specific strains during this process. Further studies with a large number of Mtb strains, encompassing the other main Mtb lineages, are inevitable.

Cystic Fibrosis (CF) is a life-threatening autosomal recessive disease. The purpose of this study was to evaluate the value of Polymerase Chain Reaction (PCR) in CF patients with Nontuberculous Mycobacteria (NTM) negative sputum culture.  

This is a descriptive cross-sectional study. The population included all children with CF, aged between 5 - 18 years old, with an NTM negative sputum culture. The patient's sputum samples were sent for smear and culture of NTM, RFLP PCR, and PCR sequence.  

In total, 57 CF patients with negative NTM sputum culture were enrolled. Nine patients (15.78%) had positive sputum PCR for NTM. Among these strains, Mycobacterium simiae was the most common one with 5 cases (8.77% of total positive cases).  

PCR can be used as an alternative diagnostic method for NTM in CF patients with negative NTM sputum culture, always under clinical suspicion of the disease.

Akkermansia muciniphila, an important member of the gastrointestinal microbiota, is involved in the functioning of the host immune system. We aimed to investigate the effect of A. muciniphila and its OMVs on the expression of microRNA-21 and microRNA-34a involved in the maturation of human dendritic cells. A. muciniphila was cultured on a mucin-containing medium and its OMVs were extracted by ultracentrifugation. Extraction of peripheral blood mononuclear cells (PBMCs) was performed using Ficoll’s density gradient centrifugation method. Monocytes were differentiated into dendritic cells in the presence of interleukin-4 cytokines and granulocyte-monocyte colony-stimulating factor. Then, A. muciniphila at MOI 50 and 100, OMVs at a dose of 50 µg/µl, dexamethasone (to induce tolerogenic dendritic cells), and the LPS (to induce mature dendritic cells) were incubated. Finally, the expression of microRNA-21 and microRNA-34a was measured by real-time PCR. The morphological characteristics of the extracted OMVs showed that their size was between 20-200 nm. In LPS treatment, there were longer cytoplasmic growths than OMVs of dexamethasone and A. muciniphila groups. MicroRNA-21 expression was decreased in the LPS group compared to dexamethasone, A. muciniphila, and OMV groups, although this decrease was not significant (P> 0.05). In addition, microRNA-34a expression was significantly increased in the LPS group, which was reversed by treatment with dexamethasone, A. muciniphila, and OMV (P <0.001). MicroRNA-21 and microRNA-34a can exhibit anti-inflammatory and pro-inflammatory functions. A. muciniphila and its OMVs appear to be a viable option for introduction as a new generation probiotic.

Tuberculosis infection still represents a global health issue affecting patients worldwide. Strategies for its control may be not as effective as it should be, specifically in case of resistant strains of Mycobacterium tuberculosis (M.tb.) In this regard, the role of mycobacterial methyltransferases (MTases) in TB infection can be fundamental, though it has not been broadly deciphered.

Five resistant isolates of M.tb were obtained. M.tb H37Rv (ATCC 27249) was used as a reference strain. Seven putative mycobacterial MTase genes (Rv0645c, Rv2966c, Rv1988, Rv1694, Rv3919c, Rv2756c, and Rv3263) and Rv1392 as SAM synthase were selected for analysis. PCR-sequencing and qRT-PCR were performed to compare mutations and expression levels of MTases in different strains. The 2-ΔΔCt method was employed to calculate the relative expression levels of these genes.

Only two mutations were found in isoniazid resistance (INHR) strain for Rv3919c (T to G in codon 341) and Rv1392 (G to A in codon 97) genes. Overexpression of Rv0645c, Rv2756c, Rv3263, and Rv2966c was detected in all sensitive and resistant isolates. However, Rv1988 and Rv3919c decreased and Rv1694 increased in the sensitive strains. The Rv1392 expression level also decreased in INHR isolate.

We found a correlation between mycobacterial MTases expression and resistance to antibiotics in M.tb strains. Some MTases undeniably are virulence factors that specifically hijack the host defense mechanism. Further evaluations are needed to explore the complete impact of mycobacterial MTases within specific strains of M.tb to introduce novel diagnosis and treatment strategies.

Chronic kidney disease (CKD) is a leading cause of death and morbidity in developed countries. Although recent studies have shown that the prevalence of thyroid disorders is higher in individuals with CKD, the underlying mechanisms are not clear. Therefore, this study aimed to evaluate the blood levels of thyroid hormones in diabetic (diabetes type 2) and non-diabetic patients with end-stage renal disease under hemodialysis treatment.

Thyroid-stimulating hormone (TSH), 3, 5, 3', 5'-tetraiodothyronine (T4/thyroxine), and 3, 3', 5-triiodothyronine (T3), were measured. Furthermore, kidney function tests (urea and creatinine), uric acid, serum lipid profile, and fasting blood glucose were measured using spectrophotometry-based methods.

There was no significant difference between the hemodialytic-diabetic subjects (HDS) and hemodialytic-non-diabetic subjects (HNDS) regarding the levels of thyroid function hormones, including TSH, T4, and T3. However, the ratio of triiodothyronine (T3) to thyroxine (T4) (T3/T4 ratio) was significantly different between the HDS and HNDS (P<0.05). These ratios (mean±standard error of the mean) were obtained at 0.220±0.026 and 0.554±0.12 in female HDS and HNDS, respectively. On the other hand, regarding males, these ratios were determined at 0.205±0.01 and 0.295±0.05 in HDS and HNDS, respectively.

Homeostasis disturbance in the T3/T4 ratio hemostasis is present in HDS, compared to HNDS; however, it is not related to the hypothalamic-pituitary-thyroid axis. Peripheral factors, including the activities of iodothyronine deiodinase type 1 and type 2 enzymes, which are involved in regulating serum levels and converting T4 to T3, are probably responsible for the observed differences.

Bacteria naturally secret nano-scale vesicles containing a wide range of biomolecules, such as proteins, DNA, and RNA. These vesicles are called extracellular vesicles (EVs). EVs play important roles in host-microbiota interactions. For isolating EVs, different methods have been proposed and each method has its advantages and also limitations. Therefore, in the current study, efficacy of two methods used for extraction of EVs was investigated.

For this purpose, Bifidobacterium bifidum was cultured in MRS broth under anaerobic conditions. In the first isolation protocol, ultra-centrifugation was used (Ultra-method) and in the second protocol, ultra-centrifugation (Non-Ultra method) was not used. After isolation, protein content was measured by the NanoDrop system. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) technique was utilized to compare protein pattern of the EVs. Scanning electron microscopy (SEM) images of the EVs҆ samples were taken and size of the EVs was evaluated by Digimizer software.

The results showed that the EVs isolated by the Ultra-method had significantly higher vesicle-associated protein content compared to those isolated by the Non-Ultra method (3.42 and 0.26 mg/ml, respectively). More and larger EVs (up to 235 nm and with frequent size ranging between 100 – 125 nm) were isolated by the Ultra-method compared to the Non-Ultra method (up to 117 nm and with frequent size ranging between 50–75 nm). Also, protein patterns of the EVs were similar in both methods and protein bands were observed at 25 to 250 KDa in both methods.

Our results showed that ultra-centrifugation method is a more proper method for isolation of B. bifidum-derived EVs and produces a higher amount of EVs with higher protein content and proper sizes. However, further studies are required to confirm our results.

Gut microbiota regulates the production of signaling molecules, such as serotonin or 5-Hydroxytryptamine: 5-HT in the host. Serotonin is a biogenic amine that acts as a neurotransmitter in the gut and brain. There is a perfect interaction between human gastrointestinal microbiota and the serotonin system. The gut microbiota plays an important role in the serotonin signaling pathways through the gut-brain axis. It also has a major role in the pathophysiology of serotonin-related metabolic and physiological diseases. The aim of this review was to investigate the relationship between gut microbiota and their role in regulating peripheral serotonin levels. This study could be highly important since there is paucity of information on the relationship between intestinal microbiota and the serotonin system. Numerous studies have shown that changes in the gut microbiota may modulate serotonin signaling system. Also, any disorder in the serotonin system and lack of homeostasis in this system can be effective in the homeostasis shift of intestinal microbiota to dysbiosis and ultimately play a role in causing inflammation in the intestine and gastrointestinal disorders. Evidence on the exact mechanisms of the interaction between intestinal microbiota and serotonin levels indicates a link between intestinal microbiota and this system. Current review showed that gut microbiota could affect the serotonin system through the gut-brain axis. Serotonin signaling in the gut-brain axis could be considered in new therapies to improve serotonin-related disorders. Therefore, further studies are proposed to more accurately determine the association between the gut microbiota and the serotonin system.

Hepatitis E virus (HEV) causes emerging diseases in poor regions of the world. The ORF2 is the only protein encoded by the virus to make the viral capsid. The aggregation of proteins into inclusion bodies (IBs) while expressing ORF2 is a major challenge in bioengineering.

The ORF2 conserved sequence was expressed in Escherichia coli BL21 and assessed by a modified SDS-PAGE containing a weak denaturing environment to solubilize the recombinant ORF2 protein and Western blotting. The protein of interest was evaluated by secondary structure prediction using SOPMA, homology modeling by I-TASSER and Circular Dichroism analyses. The function of the recombinant protein was investigated by an in-house ELISA using serum specimens of HEV infected patients.

The solubilized form of ORF2 protein was successfully expressed in E. coli BL21 and was confirmed by SDS-PAGE and Western blotting. Secondary structure prediction, homology modeling and CD analysis of the protein of interest demonstrated that the native structure of ORF2 was almost intact. The specific anti-HEV antibody was detected using this recombinant protein and an in-house ELISA test.

We achieved new combinations of chemical agents, consisted of low concentrations of urea and detergents to overcome the aggregation of ORF2 protein in IBs inside E. coli BL21.

Obesity is a complex disorder influenced by various genetic and environmental factors. It has been shown that gut microbiota, which colonizes gastrointestinal tract, has a substantial role as an environmental factor in the pathophysiology of obesity. Since the composition of gut microbiota alters with regard to different criteria, such as ethnicity, geographical location, diet, lifestyle, age, and gender, we aimed to determine firmicutes/bacteroidetes (F/B) ratio and the abundance of important gut microbiota members, Akkermansia muciniphila, Faecalibacterium prausnitzii, Roseburia, Bifidobacterium, and Prevotella in Iranian obese and normal weight individuals, for the first time.

In this study, 50 normal and 50 obese subjects were recruited and classified based on their BMI into normal weight and obese groups. Stool samples were collected. Following DNA extraction from the samples, quantitative PCR was conducted based on 16s rDNA universal primers. Finally, the correlation between the bacterial abundance and obesity was analyzed by statistical analyses.

We observed a significant increase of F/B ratio in the obese group, compared to the normal weight group (p = 0.002). Although A. muciniphila (p = 0.039) and Bifidobacterium (p = 0.049) abundance significantly decreased, the abundance of F. prausnitzii (p = 0.046) significantly elevated with BMI increase in the studied groups.

Owing to the importance of the gut microbiota composition in obesity development, determination and targeted restoration of gut microbiota pattern could be valuable in the control and treatment of obesity in certain populations.

Ventilator-associated pneumonia (VAP) is a type of hospital acquired pneumonia with the mortality rate between 27% and 76% that develops more than 48–72 h after endotracheal intubation. Possible causes leading to this infection can be Mycoplasma pneumoniae. The objective of this study was to determine the presence of Mycoplasma pneumoniae in bronchoalveolar samples of patients with VAP who admitted in the intensive care unit (ICU).

In this cross-sectional study, 103 bronchoalveolar lavage samples were collected from VAP patients who admitted to ICU in Loghman, Erfan Niyayesh and Erfan Hospitals. Then, samples were investigated for presence of Mycoplasma pneumoniae using nested-PCR method with 16S rRNA gene.

4 (3.9%) patients were positive for Mycoplasma pneumoniae. There was a significant relationship between the positive infectious agents with clinical signs (P=0.017) and the duration of using ventilator (P=0.043).

The results of this study, as a first study in Iran, showed that Mycoplasma pneumoniae can be considered as true pathogens of the respiratory tract in patients with VAP and should be given more attention. To confirm the results of this study, further research is needed to reveal the association of this bacterium with VAP

The useful and effective role of exercise program to prevent cardiac tissue apoptosis and fibrosis in ovariectomized type 2 diabetic (T2DM) rats (OVR.D) is well known. The current study aimed to investigate the simultaneous effects of T2DM and swimming plan on the expression of some apoptotic, anti-apoptotic biomarkers and glycogen changes in the cardiac muscle tissue of ovariectomized (OVR) rats. Forty rats were randomly sorted into 4 equal categories; sham, OVR, OVR.D and diabetic ovariectomized with an 8 week of swimming plan (OVR.D.E). Lipid profile and miR-133, Bcl-2, Bax, caspase-3 and caspase-8 levels were evaluated in the cardiac tissue. Ovariectomy significantly (P-value<0.05) increased cholesterol, triglyceride, LDL, Bax, caspase-3, caspase-8 and decreased (P-value<0.05) HDL, miR-133, Bcl-2 in the cardiac tissue and a further reduction in the expression of miR-133, Bcl-2 and an enhancement in Bax, caspase-3 and caspase-8 in OVR.D rats was observed (P-value<0.01). However, exercise training significantly reversed all the measured parameters (P-value<0.05). Also, exercise training improved abnormal tissue structure, fragmentation and irregular form of glycogen granules in the OVR.D.E compared to OVR and OVR.D animals. Exercise training could prevent the cardiac disturbance, enhance the expression of anti-apoptotic markers and decrease apoptotic biomarkers in the hearts of OVR.D animals. Therefore, based on the findings of this study suggested using the exercise’s beneficial effects for prevention of the cardiac cell death in OVR.D animals.

We assessed effect of Akkermansia muciniphila and its extracellular vesicles on toll-like receptors and tight junction expression in human epithelial colorectal adenocarcinoma cells (Caco-2). The intestinal microbiota plays an important role in the intestinal homeostasis through its metabolites and derivatives. Interacting with immune cells and intestinal epithelial pattern recognition receptors (PRRs), intestinal microbiota regulates the function of the digestive barrier and inflammation caused by the metabolic diseases. A. muciniphila was cultured on a mucin-containing medium and its EVs was extracted by ultracentrifugation. This bacterium was treated in the MOI=10 and its EVs at the concentrations of 0.1, 0.5 and 5 µg on Caco-2 cells. After 24 hours, the expression of tight junction and toll-like receptor genes were investigated by quantitative real time PCR method. A. muciniphila increased the expression of tlr2 and tlr4. However, EVs at all of the concentrations showed a decrease in tlr4 expression. EVs at the concentrations of 0.1 and 0.5 µg/ml decreased the expression of tlr2. A. muciniphila significantly increased the expression of ocldn and cldn4. Both this bacterium and EVs increased the expression of zo2 in the cell line. Furthermore, this data show that A. muciniphila derived EVs have a dose-independent effect on Caco-2 cells. This preliminary research shows A. muciniphila and its EVs both may increase the integrity of the intestinal barrier. A. muciniphila derived EVs also reduces the inflammation so that EVs of this bacterium can be used as an appropriate target for the treatment of metabolic syndrome and inflammatory bowel diseases.Keywords: Gut microbiota, Akkermansia muciniphila, Toll-like receptor, Tight junction protein, Extracellular vesicle.(Please cite as: Ashrafian F, Behrouzi A, shahriary A, Ahmadi Badi S, Davari M, khatami SH, et al . Comparative study of effect of Akkermansia muciniphila and its extracellular vesicles on toll-like receptors and tight junction. Gastroenterol Hepatol Bed Bench 2019;12(2):163-168).

The aim of present study is to investigate the effect of fatty acids on the outer membrane vesicles (OMVs) produced by Bacteroides spp. Bacteroides spp. is the important member of Gut microbiota that employ OMVs production for interact with host. Besides, dietary fatty acids could influence on determination of gut microbiota composition and immune response. In this regard, we evaluated the effect of fatty acids on the growth and OMVs production of Bacteroides fragilis and Bacteroides thetaiotaomicron. B. fragilis and B. thetaiotaomicron were grown on BHI broth with and without palmitic and palmitoleic acids as saturated and unsaturated fatty acids, respectively. OMVs were extracted using multiple centrifugation and tris-ethylene diamine tetra acetic acid (EDTA)-Sodium deoxy cholate buffers.  Physicochemical properties of OMVs were detected by electron microscopy (SEM), Bradford Coomassie brilliant blue assay and SDS-PAGE. Data were analyzed with One-way ANOVA using SPSS. The growths of both Bacteroides were significantly increased by palmitic acid. Nevertheless, palmitoleic acid had no significant effect on them. Palmitic acid significantly decreased and increased the production of B. fragilis OMVs at low and high concentration, respectively. However, the production of B. thetaiotaomicron OMVs was not significantly affected by palmitic acid. Although palmitoleic acid had a significant decreasing effect on the production of B. fragilis OMVs, it significantly increased the production of B. thetaiotaomicron OMVs at low concentration. In conclusion we reported that palmitic acid had a stimulatory effect on the growth of B. fragilis and B. thetaiotaomicron and had a dose dependent effect on the production of B. fragilis OMVs. Also producing of B. thetaiotaomicron OMVs was affected by palmitoleic acid in a dose dependent manner.Keywords: Bacteroides fragilis, Bacteroides thetaiotaomicron, Outer membrane vesicle, Palmitic acid, Palmitoleic acid.(Please cite as: Mirjafari Tafti ZS, Moshiri A, Ettehad Marvasti F, Tarashi S, Sadati Khalili SF, Motahhary A, et al. The effect of saturated and unsaturated fatty acids on the production of outer membrane vesicles from Bacteroides fragilis and Bacteroides thetaiotaomicron. Gastroenterol Hepatol Bed Bench 2019;12(2):155-162).

Methicillin-resistant Staphylococcus Aureus (MRSA) is an important infection source in dentistry for different disinfectants to be used to prevent its transmission. Furthermore, a variety of chemical disinfectants are developed to remove bacterial infections from the dental care workers' hands and claims are made regarding their superiority in infection control, although all requires scientific investigations. The aim of present study was to compare the effects of chemical hand-disinfectants Micro Zed HD, Aseptoman and Decosept on MRSA (methicillin resistant staphylococcus aureus) in different periods of time. In this experimental study, the antibacterial efficacy of three hand-disinfectants on standard strain of MRSA (USA300: ATCC® BAA-1717™) was evaluated according to European standard of evaluating antiseptics (EN 1040:2005 CSN EN). First we prepared a 0.5 Mc Farland (108 CFU/ml) suspension of MRSA, and exposed to three disinfectants for 15, 30, 60 and 90 seconds. Then, they were transferred to separate plates of Mueller-Hinton medium and incubated in 37◦C for 24 hours. The plates were compared then with control plate to evaluate the efficacy of materials on bacteria by calculating the CFU/ml of plates. Three hand-disinfectants evaluated in this study had the maximum anticabterial effect on MRSA in the minimum time of exposure (15 seconds), and we found no trace of growth in any plates. The three hand-disinfectans (MicroZed HD, Aseptoman and Decosept) in the concentration suggested by their companies, showed no difference in efficacy to remove MRSA from hands.

Nonencapsulated, nontypeable Haemophilus influenzae (NTHi) is considered an important cause of acute otitis in children and respiratory diseases among adults. The bacteria express several outer membrane proteins, some of which have been studied as vaccine candidates. Protein D is a highly conserved surface lipoprotein, which has been found in strains of both encapsulated and nonencapsulated H. influenzae.
Opsonin and protective antibodies against protein D play major roles in the prevention of infections caused by NTHi. Since NTHi can be also an intracellular organism, it needs to be removed through immune-mediated mechanisms.
In this study, groups of BALB/c mice were subcutaneously immunized with recombinanat truncated D protein and an aluminum hydroxide (alum) adjuvant or protein D combined with an outer membrane vesicle (OMV) adjuvant from Neisseria meningitidis bacteria. Then, opsonophagocytic activities of antibodies were measured in serum samples collected on days 14, 28, and 42. The levels of interleukin-4 (IL-4), IL-10, and interferon-gamma were measured in splenocyte cultures of immunized mice.
The opsonophagocytic activity of antibodies significantly increased in the immunized mice, compared to the control group, particularly on day 42. In addition, the secretion level of cytokines significantly increased in both groups of immunized mice, compared to the control group.
The results of this study demonstrated that recombinant truncated D protein can induce specific immune responses against nonencapsulated H. influenzae. It was suggested that the recombinant truncated D protein, as a vaccine candidate against the nonencapsulated strains of H. influenza, is essential in protection and development of sustainable immunity against infections caused by this bacterium.

Different serotypes of Haemophilus influenzae is now divided into 2 divisions: encapsulated and unencapsulated. Multiple locus variable number tandem repeat analysis (MLVA) includes such specifications as the extra power of separation, ease of data interpretation, and epidemiological data accordance, which have made it an appropriate molecular device for good typing and phylogenetic analysis of bacterial pathogens.
In this research, cultured samples were studied and strains identified through biochemical tests were recognized. Moreover, DNA was extracted and studied qualitatively and quantitatively. Four pairs of specialized primers related to H. influenzae variable number tandem repeats (VNTR) and preparation of PCR were designed according to the regulated program. Also, electrophoresis of PCR products was performed. Finally, the interpretation of electrophoresis gel was done with respect to the observable bands showing the presence or absence of the required sequence in the samples related to every primer.
This study was the first MLVA typing of the unencapsulated H. influenzae in Iran. In this research, the VNTR sequences were tested in 30 strains without the unencapsulated H. influenzae. Among 30 mentioned strains, for which MLVA profile was obtained in this research, 25 different MLVA types were observed. Likewise, there was no repetition in VNTR sequences resulting from PCR in few H. influenzae. In all these cases, the number of repetitions in MLVA profile was determined as 0, except for one of the primers in 4 strains, which was 16%. However, this did not occur for the other VNTRs.
The highest diversity of the repeats was for VNTR5 (7 types), followed by VNTR6 with 6 types of repeats, and VNTR12-1 and VNTR12-2 with 3 different types.