Molecular epidemiology of nontuberculous mycobacteria isolated from tuberculosis-suspected patients

It is a growing problem around the world to deal with nontuberculous mycobacteria infection (NTM), but its clinical significance is still largely unknown. This study aims to investigate the epidemiology of NTM infections from various clinical samples and determine their clinical significance. From December 2020 to December 2021, 6125 clinical samples were collected. In addition to phenotypic detection, genotypic detection through multilocus sequence typing (hsp65, rpoB, and 16S rDNA genes) and sequencing was also conducted. Records of patients were consulted for clinical information, such as symptoms and radiological findings. Of the 6,125 patients, 351 (5.7%) were positive for acid-fast bacteria (AFB). Out of 351 AFB, 289 (82.3%) and 62 (17.7%) subjects were identified as M. tuberculosis complex (MTC) and NTM strains, respectively. Isolates of Mycobacterium simiae and M. fortuitum were the most frequent, followed by isolates of M. kansasii and M. marinum. We also isolated M. chelonae, M. canariasense, and M. jacuzzii, which are rarely reported. Symptoms (P = 0.048), radiographic findings (P = 0.013), and gender (P = 0.039) were associated with NTM isolates. M. Fortuitum, M. simiae, and M. kansasii presented with bronchiectasis, infiltration, and cavitary lesions most frequently, while cough was the most common symptom. In conclusion, Mycobacterium simiae and M. fortuitum were presented in seventeen and twelve NTM isolates from the collected samples. There is evidence that NTM infections in endemic settings may contribute to the dissemination of various diseases and the control of tuberculosis. In spite of this, further research is needed to evaluate the clinical significance of NTM isolates.

Comparison of clinicodemographic characteristics and pattern of vascular involvement in 126 patients with Takayasu arteritis: a report from Iran and Turkey

Takayasu arteritis (TA) is an extremely uncommon vasculitis that primarily affects the aorta and its branches. Due to the genetic and ethnicity effect, a diverse array of TA clinical manifestations has been reported worldwide. The purpose of the present study was to compare the clinicodemographic characteristics and pattern of vascular involvement of Iranian and Turkish TA patients. This study was a retrospective, cross-sectional investigation of 126 TA patients in Iran and Turkey. All of the variables analyzed were extracted from historical medical records. In 126 TA patients, the ratio of females to males was 8.6:1, and the average age at onset of disease was 30.5±11.1 years. Fatigue (49.2%) and a weak or absent pulse (79.4%) were the most prevalent symptoms and signs, respectively. The most prevalent angiographic classifications were types V and I in Iranian patients (41.09%) and type I in the Turkish population (47.7%) The left subclavian artery was the vessel most frequently affected by TA (66.6%). Our findings indicated that there were no significant differences between the two countries in terms of clinicodemographic characteristics or vascular involvement. Some clinical manifestations, such as claudication, were more prevalent in the Turkish population due to a higher incidence of occlusive lesions in the right subclavian artery.

Mixed pulmonary infection with four isolates of nontuberculous mycobacteria: a case report of mycobacterium bacteremicum infection

Background

A mixed pulmonary infection of Mycobacterium bacteremicum and three different isolates of nontuberculous mycobacteria (NTM) is an unusual clinical manifestation and have not yet been indicated. In this case report, we reported four isolates of NTM using phenotypic and genotypic test of pulmonary sample in Tehran, Iran.

Case presentation

We report a case of severe pulmonary disease in a 19-year-old male patient with productive cough, shortness of breath, and low-grade fever for several weeks. The C-reactive protein (CRP) level (80.2 mg/L) and erythrocyte sedimentation rate (ESR) (95 mm/h) were high. The computed tomographic scan indicated bronchiectasis, nodular opacities, consolidation, and cavitary lesions on both sides. The result of purified protein derivative (PPD) test was equal to 15 mm. The sequences of hsp65, rpoB, and 16S rDNA genes indicated more than 99% homology to four isolates of nontuberculous mycobacteria (NTM), including Mycobacterium fortuitum, M. chelonae, M. mucogenicum, and M. bacteremicum. We found that all four strains were susceptible to amikacin, cefoxitin, ciprofloxacin, clarithromycin, imipenem, and linezolid. The patient was treated with ciprofloxacin, clarithromycin, and amikacin, along with Montelukast, for five months.

Conclusion

We report a case of severe pulmonary infection by four isolates of NTM. After treatment, the patient reported complete resolution of the signs and a weight gain of 5 kg; also, the CRP and ESR were normal. Nine months after the infection diagnosis, a new CT scan revealed further improvements.

Isolation of nontuberculous mycobacteria species from different water sources: a study of six hospitals in Tehran, Iran

Purpose

Nontuberculous mycobacteria (NTM) are ubiquitous bacteria that are naturally resistant to disinfectants and antibiotics and can colonize systems for supplying drinking water. Therefore, this study aimed to evaluate the prevalence of NTM in the drinking water of six hospitals in Tehran, Iran.

Methods

Totally, 198 water samples were collected. Each water sample was filtered via a membrane filter with a pore size of 0.45 µm and then decontaminated by 0.005% cetylpyridinium chloride. The membrane filters were incubated on two Lowenstein-Jensen media at 25 °C and 37 °C for 8 weeks. The positive cultures were identified with phenotypic tests, and then NTM species were detected according to the hsp65, rpoB, and 16S rDNA genes. Drug susceptibility testing (DST) was also carried out.

Results

Overall, 76 (40.4%) of the isolates were slowly growing mycobacteria (SGM) and 112 (59.6%) of the ones were rapidly growing mycobacteria (RGM). The most common NTM were Mycobacterium aurum, M. gordonae, M. phocaicum, M. mucogenicum, M. kansasii, M. simiae, M. gadium, M. lentiflavum, M. fortuitum, and M. porcinum. Among these 188 samples, NTM ranged from 1 to > 300 colony-forming unit (CFU) /500 mL, with a median of 182 CFU/500 mL. In the infectious department of all hospitals, the amount of CFU was higher than in other parts of the hospitals. The DST findings in this study indicated the diversity of resistance to different drugs. Among RGM, M. mucogenicum was the most susceptible isolate; however, M. fortuitum showed a different resistance pattern. Also, among SGM isolates, M. kansasii and M. simiae, the diversity of DST indicated.

Conclusions

The current study showed NTM strains could be an important component of hospital water supplies and a possible source of nosocomial infections according to the CFU reported in this study. The obtained findings also help clarify the dynamics of NTM variety and distribution in the water systems of hospitals in the research area.

An effective nano drug delivery and combination therapy for the treatment of Tuberculosis

Drug resistance in tuberculosis is exacerbating the threat this disease is posing to human beings. Antibiotics that were once effective against the causative agent, Mycobacterium tuberculosis (Mtb), are now no longer usable against multi- and extensively drug-resistant strains of this pathogen. To address this issue, new drug combinations and novel methods for targeted drug delivery could be of considerable value. In addition, studies have shown that the use of the antidepressant drug fluoxetine, a serotonin reuptake inhibitor, can be useful in the treatment of infectious diseases, including bacterial infections. In this study, an isoniazid and fluoxetine-conjugated multi-walled carbon nanotube nanofluid were designed to increase drug delivery efficiency alongside eliminating drug resistance in vitro. The prepared nanofluid was tested against Mtb. Expression levels of inhA and katG mRNAs were detected by Real-time PCR. ELISA was applied to measure levels of cytokine secretion (TNF-α, and IL-6) from infected macrophages treated with the nano delivery system. The results showed that these nano-drug delivery systems are effective for fluoxetine at far lower doses than for free drugs. Fluoxetine also has an additive effect on the effect of isoniazid, and their concomitant use in the delivery system can have significant effects in treating infection of all clinical strains of Mtb. In addition, it was found that the expression of isoniazid resistance genes, including inhA, katG, and the secretion of cytokines TNFα and IL6 under the influence of this drug delivery system is well regulated. It was shown that the drug conjugation can improve the antibacterial activity of them in all strains and these two drugs have an additive effect on each other both in free and conjugated forms. This nano-drug delivery method combined with host targeted molecules could be a game-changer in the development of a new generation of antibiotics that have high therapeutic efficiencies, low side effects, and the potential to overcome the problem of drug resistance.

The Value of Sputum Polymerase Chain Reaction for Detection of Nontuberculous Mycobacteria in Cystic Fibrosis Patients with Negative Nontuberculous Mycobacteria Sputum Culture

Background: 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.

Methods: 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.

Results: 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).

Conclusion: 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.

The anti-inflammatory effects of Akkermansia muciniphila and its derivates in HFD/CCL4-induced murine model of liver injury

Inflammation plays a critical role in the promotion of hepatocyte damage and liver fibrosis. In recent years the protective role of Akkermansia muciniphila, a next-generation beneficial microbe, has been suggested for metabolic and inflammatory disorders. In this study, we aimed to evaluate the effects of live and pasteurized A. muciniphila and its extra cellular vesicles (EVs) on inflammatory markers involved in liver fibrosis in a mouse model of a high-fat diet (HFD)/carbon tetrachloride (CCl₄)-induced liver injury. Firstly, the responses of hepatic stellate cells (HSCs) to live and pasteurized A. muciniphila and its EVs were examined in the quiescent and LPS-activated LX-2 cells. Next, the anti-inflammatory effects of different forms of A. muciniphila were examined in the mouse model of HFD/CCl₄-induced liver injury. The gene expression of various inflammatory markers was evaluated in liver, colon, and white adipose tissues. The cytokine secretion in the liver and white adipose tissues was also measured by ELISA. The results showed that administration of live and pasteurized A. muciniphila and its EVs leads to amelioration in HSCs activation. Based on data obtained from the histopathological analysis, an improvement in gut health was observed through enhancing the epithelium and mucosal layer thickness and strengthening the intestinal integrity in all treatments. Moreover, live A. muciniphila and its EVs had inhibitory effects on liver inflammation and hepatocytes damage. In addition, the tissue cytokine production and inflammatory gene expression levels revealed that live A. muciniphila and its EVs had more pronounced anti-inflammatory effects on liver and adipose tissues. Furthermore, EVs had better effects on the modulation of gene expression related to TLRs, PPARs, and immune response in the liver. In conclusion, the present results showed that oral administration of A. muciniphila and its derivatives for four weeks could enhance the intestinal integrity and anti-inflammatory responses of the colon, adipose, and liver tissues and subsequently prevent liver injury in HFD/CCL₄ mice.

Extracellular vesicles and pasteurized cells derived from Akkermansia muciniphila protect against high-fat induced obesity in mice

Background

Several studies have shown that probiotics have beneficial effects on weight control and metabolic health. In addition to probiotics, recent studies have investigated the effects of paraprobiotics and postbiotics. Therefore, we evaluated the preventive effects of live and pasteurized Akkermansia muciniphila MucT (A. muciniphila) and its extracellular vesicles (EVs) on HFD-induced obesity.

Results

The results showed that body weight, metabolic tissues weight, food consumption, and plasma metabolic parameters were increased in the HFD group, whereas A. muciniphila preventive treatments inhibited these HFD. The effects of pasteurized A. muciniphila and its extracellular vesicles were more noticeable than its active form. The HFD led to an increase in the colonic, adipose tissue, and liver inflammations and increased the expression of genes involved in lipid metabolism and homeostasis. Nevertheless, these effects were inhibited in mice that were administered A. muciniphila and its EVs. The assessment of the gut microbiota revealed significant differences in the microbiota composition after feeding with HFD. However, all treatments restored the alterations in some bacterial genera and closely resemble the control group. Also, the correlation analysis indicated that some gut microbiota might be associated with obesity-related indices.

Conclusions

Pasteurized A. muciniphila and its EVs, as paraprobiotic and postbiotic agents, were found to play a key role in the regulation of metabolic functions to prevent obesity, probably by affecting the gut-adipose-liver axis.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-021-01709-w.

Comparing mRNA expression and protein abundance in MDR Mycobacterium tuberculosis: Novel protein candidates, Rv0443, Rv0379 and Rv0147 as TB potential diagnostic or therapeutic targets

Tuberculosis (TB) is a sizable public health threat in the world. This study was conducted to determine the differential protein composition between susceptible and MDRTB strains. Tuberculosis proteins were extracted by Triton™ X-114 and ammonium sulfate. Two-dimensional gel electrophoresis protein spots were selected for identification by mass spectrometry and mRNA expression levels were measured by real- time PCR. 2DE-Western blot and T cell epitope prediction for identified proteins were made by the IEDB server. The result shows at least six protein spots (Rv0147, Rv3597c, Rv0379, Rv3699, Rv1392 and Rv0443) were differentially expressed in MDRTB isolates. However, difference in mRNA gene expression was not found in the six mRNA genes. 2DE-Western blot procedures indicated strong reaction against MDRTB proteins corresponds to 13, 16 and 55 kDa areas that might be used as new diagnostic tools. In conclusion, these MDRTB proteins identified in this study could be reliable TB diagnostic candidates or therapeutic targets.

Gene Expression and In Vitro Pharmacogenetic Studies of Dopamine and Serotonin Gene Receptors in Tuberculosis

BACKGROUND

Dopamine and serotonin receptors are present in lymphocytes, macrophages, and neutrophils, and have a mediating role in the immune system to respond to infections, including bacterial tuberculosis.

MATERIALS AND METHODS

In this study, at first, the changes in the expression pattern of 5 dopamine and 2 serotonin (5HTR2B & 5HTR2C) gene receptors were examined in the two groups of healthy and Tuberculosis patients using Real-Time PCR. Then pharmacogenetic studies aimed to induce autophagy on a lung monocyte cell line (THP1) infected with the standard strain of Mycobacterium tuberculosis (H37RV) were performed. Stimulation of the pro-inflammatory pathway by secreting cytokines before and after drug efficacy was investigated.

RESULTS

According to the result, dopamine receptor 2 genes showed decreased expression in patients with tuberculosis compared to normal individuals, and serotonin receptor genes showed increased expression. Additionally, with the effects of Bromocriptine and Fluoxetine, pro-inflammatory pathways were activated in macrophages infected with H37RV, and ELISA results showed that the levels of IL6 and TNFα secreted in these cells were significantly increased.

CONCLUSION

According to the results, these receptors agonists or antagonists can activate the autophagy pathway to kill TB bacteria.

A case report of wrist synovial infection due to Mycobacterium jacuzzii, Iran

Background

Mycobacterium jacuzzii (M. jacuzzii) was first isolated in 2003 by insertion of breast implants in Tel Aviv, Israel. In this case report, we describe our experience in detection of M. jacuzzii using phenotypic and genotypic test of wrist synovial sample.

Case presentation

A 73-year-old woman complained of pain and swelling in the right wrist for 4 months. Her body temperature was 37–38 °C, and symptoms, such as pain, swelling, and some movement limitation, were reported. Clinical laboratory parameters showed an elevated C-reactive protein (CRP) level, erythrocyte sedimentation rate (ESR), and white blood cells (WBC) count. The sequences of hsp65, rpoB, 16S rDNA, and sodA genes indicated very high homology to M. jacuzzii.

Conclusion

We report a case of synovial infection caused by M. jacuzzii in a patient with severe wrist pain in Iran, who was treated with amikacin, levofloxacin, and ethambutol. The outcomes of treatment after 8 months were positive, and no recurrence of infection was reported in the patient.

The regulation of Niemann-Pick C1-Like 1 (NPC1L1) gene expression in opposite direction by Bacteroides spp. and related outer membrane vesicles in Caco-2 cell line

Purpose

The intestine has substantial role in cholesterol homeostasis due to the presence of various cholesterol transporters and gut microbiota. Bacteroides spp. are important members of gut microbiota that employ outer membrane vesicles (OMVs) to interact with host. In this regard, we evaluated the effect of Bacteroides fragilis, Bacteroides thetaiotaomicron and related OMVs on the gene expression of important cholesterol transporters, Niemann-Pick C1-Like 1 (NPC1L1), ATP-binding cassette (ABCA1), and liver X receptors (LXRs) in Caco-2 cells.

Methods

OMVs were isolated from overnight brain heart infusion (BHI) broth of bacterial standard strains using deoxycholate and assessed by Scanning electron microscopy (SEM). The relative change in genes expression was assessed by Quantitative reverse transcription PCR (RT-qPCR) based on SYBR Green and 2^-∆∆ct method in Caco-2 cells that were treated with bacteria and OMVs. Data were statistically analyzed with GraphPad Prism software. Finally, pathway enrichment based on the studied genes was performed using Cytoscape plugin ClueGO.

Results

B. fragilis (P value = 0.002) and B. thetaiotaomicron (P value = 0.001) significantly reduced NPC1L1 gene expression in Caco-2 cells. Interestingly, NPC1L1 transcripts were significantly increased by both OMVs(P value = 0.04) (P value = 0.01). Also, LXRβ was significantly down regulated by B. thetaiotaomicron (P value = 0.02). ClueGO analysis on the studied genes demonstrated several functional groups which involve in lipid and cholesterol metabolism.

Conclusion

The opposite effect of B. fragilis, B. thetaiotaomicron and related OMVs on the NPC1L1 gene expression was observed in Caco-2 cells. Interestingly, these effects partially were in line with the alternation of LXRs expression. However, based on pathway enrichment analysis, further molecular investigations are required to elaborate in details the specific association between Bacteroides spp. and OMVs with regulation of cholesterol signaling pathways including cholesterol transport, lipid storage, lipid homeostasis and cholesterol homeostasis.

Evaluation of Mycobacterium kansasii extracellular vesicles role in BALB/c mice immune modulatory

Background

Mycobacterium kansasii as a nontuberculosis mycobacteria, naturally release extracellular vesicles (EVs) with widespread utilities. The aim of the present study was the extraction and biological evaluation of M. kansasii EV and its role in BALB/c mice immune modulatory by considering EVs medical usage specificities.

Method

Density gradient ultracentrifugation method was used to EVs extraction from standard species of M. kansasii. Biologic validation of EVs has been performed by physicochemical experiments. Immunization has been done by subcutaneous injection to BALB/c mice, then spleen cell isolation and lymphocyte transformation test and eventually ELISA cytokine assays were made for interleukin-10 (IL-10) and interferon-gamma (IFN-γ).

IBM SPSS version 22 software (SPSS. Inc., Chicago, IL, USA) was used for the data calculation. The evaluation of variables was conducted using one sample t-test.

Results

Physicochemical experiment results contribute that extracted EVs have intransitive capability to use in immunization schedule. Finally, ELISA test results showed that EVs induced IL-10 production, but have no effect on IFN-γ.

Conclusions

In this current study, EVs were prepared in high-quality composition. The results of cytokine assay revealed that the extracted EVs have anti-inflammatory property. Accordingly, this macromolecule can be used as immune modulatory agents to prevent severe immune reactions, especially in lungs disorders.

Prediction of the hidden genotype of mixed infection strains in Iranian tuberculosis patients

BACKGROUND

Patients with mixed-strain Mycobacterium tuberculosis infections may be at a high risk of poor treatment outcomes. However, the mechanisms through which mixed infections affect the clinical manifestations are not well recognized. Evidence suggests that failure to detect the pathogen diversity within the host can influence the clinical results. We aimed to investigate the effects of different genotypes in mixed infections and determine their relationship with heteroresistance in the treatment of Iranian tuberculosis patients.

METHODS

One of the genotypes was identified in the culture and another genotype pattern in the mixed infection was predicted by comparing the pattern of MIRU-VNTR between the clinical specimens and their respective cultures in each patient. For all patients, the drug susceptibility testing was carried out on three single colonies from each clinical sample. The follow-up of patients was carried out during six months of treatment.

RESULTS

Based on MIRU-VNTR profiles of clinical samples, we showed that 55.6% (25/45) of the Iranian patients included in the study had mixed infections. Patients with mixed infections had a higher rate of treatment failure, compared to others (P=0.03). By comparing clinical sample profiles to profiles obtained after culture, we were able to distinguish between major and hidden genotypes. Among hidden genotypes, Haarlem (L4.1.2) and Beijing (L2) were associated to treatment failure (6/8 patients).

CONCLUSIONS

To conclude, we propose a procedure using the MIRU-VNTR method to identify the different genotypes in mixed infections. The present findings suggest that genotypes with potentially higher pathogenicity may not be detected when performing experimental culture in patients with mixed infections.

Scrutinizing the drug resistance mechanism of multi- and extensively-drug resistant Mycobacterium tuberculosis: mutations versus efflux pumps

Background

In order to shorten the course of treatment and its effectiveness, it is essential to gain an in-depth insight into the drug resistance mechanisms of Mycobacterium tuberculosis (M. tuberculosis).

Methods

In this study, we evaluated the contribution of 26 drug efflux pumps plus target gene mutations to the drug resistance levels in multi-drug resistant (MDR)/pre-extensively drug-resistant (pre-XDR)/extensively drug-resistant (XDR) and mono-drug resistant clinical isolates of M. tuberculosis. The panels of 25 M. tuberculosis clinical strains were characterized for drug resistance-associated mutations with whole-genome sequencing and antibiotic profiles in the presence and absence of efflux inhibitor verapamil (VP).

Results

Different MICs were observed for the same target gene mutations. Out of the 16 MDR/pre-XDR/XDR isolates, 6 (37.5%) and 3 (18.8%) isolates demonstrated a significant decrease in rifampicin (RIF) MIC and isoniazid (INH) MIC due to the VP exposure (64 μg/mL), respectively. Susceptibility to RIF was fully restored in two isolates after VP exposure. Moreover, the efflux pump genes of Rv2938, Rv2936, Rv1145, Rv1146, Rv933, Rv1250, Rv876, Rv2333, Rv2459, Rv849, and Rv1819 were overexpressed in the presence of anti-TB drugs, showing the contribution of these efflux pumps to the overall resistance phenotype.

Conclusions

Our results clearly showed that efflux systems, besides spontaneous mutations, play a role in the development of INH/RIF resistance. In addition, although VP was effective in reducing the expression of some efflux pumps, it was not very successful at the phenotypic level.

Bothersome menopausal symptoms amongst postmenopausal Iranian women

OBJECTIVES

This study was undertaken to determine the impact of menopause on middle-eastern women.

METHODS

This was a cross-sectional study of 1520 women, aged 40-64 years, living in Sari, Northern Iran, recruited by multistage cluster sampling between October 2016 and April 2017. All women completed the Menopause Quality of Life Questionnaire (MENQOL) and Beck Depression Inventory-II (BDI-II).

RESULTS

Of all the women, 54.5% were perimenopausal or postmenopausal. The prevalences of any vasomotor symptom (VMS) and moderate-severely bothersome VMS were greatest for postmenopausal women aged <55 years (66.4%, 95% confidence interval (CI) 59.9-72.3% and 13.5%, 95% CI 9.6-18.6%, respectively). Having moderate-severe VMS was associated with moderate-severe depressive symptoms (adjusted odds ratio (AOR) 2.9; 95% CI 1.6-5.2; p < 0.001). Symptoms of vulvovaginal atrophy (VVA) were reported by 41.1% (95% CI 37.4-45.0%) of perimenopausal and postmenopausal women, with 22.9% (95% CI 19.8-26.3%) reporting their symptoms as moderate-severely bothersome. In women with moderate-severe VMS, the proportion with both moderate-severe depressive symptoms and moderate-severe VVA symptoms (12.1%) was four times that in women with no or mild VMS (3.3%) (p < 0.001).

CONCLUSION

One in seven perimenopausal and postmenopausal women has moderate-severely bothersome VMS and few women receive appropriate therapy. The reporting of moderate-severe VMS should alert clinicians to the likelihood of significant concurrent VVA and depressive symptoms.

The inhibitory effect of the combination of two new peptides on biofilm formation by Acinetobacter baumannii

The emergence of extensively drug-resistant (XDR) Acinetobacter baumannii strains and the limited number of efficacious antibiotics demonstrate an urgent need to develop novel agents to treat infections caused by this dangerous pathogen. To find antimicrobial peptides against A. baumannii growing either in planktonic or in biofilm mode, biopanning was carried out with a peptide library on five XDR A. baumannii strains grown in the medium containing human blood (blood biopanning) and biofilms formed by these strains (biofilm biopanning). Two groups of peptides were identified, among which two peptides N10 (from blood biopanning) and NB2 (from biofilm biopanning) were selected and synthesized for more assessments. The selected peptides showed significant binding to A. baumannii rather than to the human cell line Caco-2. Both peptides were effective against A. baumannii and showed antibacterial activities (minimum inhibitory concentration (MIC) 500 μg/ml). In the biofilm inhibition assay, NB2 reduced biofilm more efficiently (75%) than N10 (50%). The combination of the two peptides could function better than each peptide alone to prevent biofilm formation by A. baumannii. Supplementation of conventional therapy with a mixture of peptides targeting A. baumannii or using peptides to deliver antibiotics specifically to the site of infection may be promising to control A. baumannii-related diseases.

Depressive symptoms and their risk factors in midlife women in the Middle East: a systematic review

INTRODUCTION

Women may experience different menopausal symptoms across different cultures around the world. The purpose of this study was to determine the prevalence and contributing factors of depression in midlife women in the Middle East.

METHODS

Electronic databases including PubMed, Medline, PsycINFO, CINAHL, Web of Science, SCOPUS, and Google scholar were searched. The quality of articles was assessed by using the risk of bias tool.

RESULTS

Sixteen articles were used for this review. The prevalence for depressive symptoms in perimenopausal women is higher than in premenopausal women. The overall data also suggest that depressive symptoms may be more prevalent in postmenopausal women than in premenopausal women. Studies reported sociodemographic, physical, psychological, cultural and sexual risk factors for depressive symptoms in middle-aged women. Risk of bias for a majority of the studies conducted in the Middle Eastern region on depression in midlife was moderate.

CONCLUSION

Consistent with other areas in the world, midlife women in the Middle East region are at higher risk for depression due to the presence of different factors. High-quality longitudinal studies of representative samples, using validated questionnaires, are needed to provide more accurate prevalence data and the association between menopause and menopausal symptoms in women in the Middle East.

Sub-minimum inhibitory concentration of rifampin: a potential risk factor for resuscitation of Mycobacterium tuberculosis

BACKGROUND

Mycobacterium tuberculosis possesses five resuscitation-promoting factors, Rpf A to E, which are required for the resuscitation of dormancy in mycobacteria. This study explores the transcriptional profile of all five rpfs of M. tuberculosis, in response to sub-MIC concentration of rifampin, in multidrug and mono-rifampin resistant clinical isolates.

METHODS

Thirteen multidrug and two rifampin mono resistant clinical isolates were analyzed. Drug susceptibility testing and determination of MIC were performed. The relative expression of rpfs was measured, by real-time quantitative PCR.

RESULTS

A significant upregulation of relative expression (p < 0.05) was observed, as follows: 7/15(46.66%); 5/15(33.33%); 9/15(60%); 10/15(66.66%) and 9/15(60%) in rpfA, rpfB, rpfC, rpfD and rpfE, respectively.

CONCLUSION

Our results showed that the rpfs could be overexpressed in some extent in the presence of sub-MIC concentration of rifampin in multidrug and mono drug resistant M. tuberculosis. These results highlight the potential risk of sub-MIC rifampin concentrations, as a risk factor for tuberculosis reactivation.

Bias in detection of Mycobacterium tuberculosis polyclonal infection: Use clinical samples or cultures?

The application of MIRU-VNTR has unveiled that infection by Mycobacterium tuberculosis can be polyclonal. Our comparative study demonstrated that based on the studied samples (clinical specimen or culture) detection of polyclonal M. tuberculosis infection can be significantly different.

Pros and cons of direct genotyping on tuberculosis clinical samples

OBJECTIVE

Prompt genotyping of Mycobacterium tuberculosis (M. tuberculosis) is crucial for improving molecular epidemiological investigation of tuberculosis (TB).

METHODS

We performed a retrospective study to evaluate the use of 24 loci MIRU-VNTR (mycobacterial interspersed repetitive unit-variable number of tandem-repeat) directly on 135 clinical samples from 84 TB patients.

RESULTS

There was a direct correlation between genotyping on clinical samples by MIRU-VNTR and bacterial load (P = 0.001). VNTR loci were amplified successfully for 41.5% of the clinical samples (19-24 loci), 32.6% (13-18 loci), 23.7% (7-12 loci) and 2.2% (1-6 loci). Loci of 2401, 577, 2996 and 154 had the highest power to show the mixed strains infection in clinical samples.

CONCLUSIONS

Direct MIRU-VNTR is partially successful in complete genotyping of M. tuberculosis strains. On the other hand, detection of polyclonal infection is undoubtedly reliable based on the direct MIRU-VNTR.

Therapeutic application of mesenchymal stem cell-derived exosomes: A promising cell-free therapeutic strategy in regenerative medicine

Mesenchymal stem cells have emerged as promising therapeutic candidates in regenerative medicine. The mechanisms underlying mesenchymal stem cells regenerative properties were initially attributed to their engraftment in injured tissues and their subsequent transdifferentiation to repair and replace damaged cells. However, studies in animal models and patients indicated that the low number of transplanted mesenchymal stem cells localize to the target tissue and transdifferentiate to appropriate cell lineage. Instead the regenerative potential of mesenchymal stem cells has been found - at least in part - to be mediated via their paracrine actions. Recently, a secreted group of vesicles, called "exosome" has been identified as major mediator of mesenchymal stem cells therapeutic efficacy. In this review, we will summarize the current literature on administration of exosomes released by mesenchymal stem cells in regenerative medicine and suggest how they could help to improve tissue regeneration following injury.

Distribution of non-tuberculosis mycobacteria strains from suspected tuberculosis patients by heat shock protein 65 PCR-RFLP

The genus Mycobacterium contains more than 150 species. Non-tuberculosis mycobacteria (NTM) often cause extrapulmonary and pulmonary disease. Mycobacteria detection at species level is necessary and provides useful information on epidemiology and facilitates successful treatment of patients. This retrospective study aimed to determine the incidence of the NTM isolates and Mycobacterium tuberculosis (Mtb) in clinical specimens collected from Iranian patients during February 2011–December 2013, by PCR–restriction fragment length polymorphism analysis (PRA) of the hsp65 gene. We applied conventional biochemical test and hsp65–PRA identification assay to identify species of mycobacteria in specimens from patients suspected of having mycobacterial isolates. This method was a sensitive, specific and effective assay for detecting mycobacterial species and had a 100% sensitivity and specificity for Mtb and Mycobacterium avium complex (MAC) species. Using PRA for 380 mycobacterial selected isolates, including 317 Mtb, four Mycobacterium bovis and of the 59 clinical isolates, the most commonly identified organism was Mycobacterium kansasii (35.6%), followed by Mycobacterium simiae (16.9%), Mycobacterium gordonae (16.9%), Mycobacterium fortuitum (5.1%), Mycobacterium intracellulare (5.1%), Mycobacterium avium (5.1%), Mycobacterium scrofulaceum (3.4%), Mycobacterium gastri (3.4%), Mycobacterium flavescens (3.4%), Mycobacterium chelonae (3.4%) and Mycobacterium nonchromogenicum (1.7%). PRA method, in comparison with classical methods, is rapid, useful and sensitive for the phylogenetic analysis and species detection of mycobacterial strains. Mycobacterium kansasii is the most common cause of infection by NTM in patients with non-HIV and HIV which demonstrated a high outbreak and diversity of NTM strains in our laboratory.

Genotyping of Haemophilus influenzae type b strains and their incidence in the clinical samples isolated from Iranian patients

BACKGROUND AND OBJECTIVE

Haemophilus influenzae type b (Hib) is divided into two distinct genotypes, type I and type II, based on the structure of capsular polysaccharides. The capsulation locus of Haemophilus influenzae type b consists of three functionally distinct regions, designated regions 1 to 3. Region III contains hcsA and hcsB genes; however, notable sequence variation in this region can be used to recognize different Hib genotypes. The purpose of this study was to investigate the prevalence and genotype of the Hib strains isolated from patients with invasive disease in Iran.

MATERIALS AND METHODS

In the present study, 8 pairs of primers were used for identification and serotyping of encapsulated Haemophilus influenzae strains, as well as confirmation of species identification. Additionally, in order to identify the capsular genotypes of Haemophilus influenzae type b (type I and II), two additional primer pairs were used to amplify the hcsA gene.

RESULTS

Out of 50 isolates of H. influenzae, four were found to be type b. Interestingly, among these 4 Hib isolates, 2 strains belonged to the type-II category.

CONCLUSION

Our study shows that the prevalence of both Hib types I and II seems to be high in Iran.

HSP65-PRA identification of non-tuberculosis mycobacteria from 4892 samples suspicious for mycobacterial infections

Various molecular methods have been used for the rapid identification of mycobacterial species. In this survey, evaluation of antibiotic resistance and PCR-restriction fragment length polymorphism analysis (PRA) of the hsp65 gene was carried out for identification of non-tuberculosis mycobacteria (NTM) isolates from different clinical specimens. Forty-eight different mycobacterial isolates were selected and followed by the conventional and PRA of hsp65 for species identification. The antibiotic susceptibility test was carried out according to standard methods. A 439 bp PCR product of hsp65 in all selected isolates was amplified and digested with the BstEII and HaeIII restriction enzymes. The restriction fragment length polymorphism (RFLP) patterns were analyzed for species identification. Using PRA for 48 mycobacterial selected isolates, including 15 M. tuberculosis, one M. bovis and all 32 isolates of NTM, revealed 11 different species among the NTM isolates. The most frequent NTM isolates were M. kansasii, M. gordonae III, M. marinum, M. chelonae, M. scrofluaceum and M. gastri. In most cases, the PRA results were perfectly in accordance with the classical biochemical method. Combination of resistance to rifampin and isoniazid was present among M. kansasi, M. gordoniae III, M. scrofluaceum, M. chelonae, M. marinum, M. gastri, M. gordoniae II and M. trivale isolates. A high incidence of co-resistance to six, five, four and three anti-TB drugs was observed in 18.5%, 9.1%, 6.6% and 11.7% of all NTM isolates, respectively. Our results showed that PRA, in comparison with classical methods, is rapid and accurate enough for the identification of mycobacterial species from LJ medium. Additionally, we found that in Iran we have a highly diverse population of NTM isolates among patients suspected of having TB.

Future perspectives for hand transplant in iran

Hand transplant program is a communion of physicians and researchers during the current decade. 72 hands and digits were transplanted in 53 patients over the past 13 years. Unlike a solid organ transplant, hand transplantation involves various tissues, so it is called "composite tissue allotransplantation." This article discusses the plans for performing the first hand transplant in Iran.