Bacteroides fragilis in saliva: investigating links with ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) is a long-term bowel inflammation of unknown cause. Recent research points to gut microbiota, especially Enterotoxigenic Bacteroides fragilis (ETBF), in UC's development. This study examined the presence of Bacteroides fragilis (B. fragilis) and ETBF in the saliva of UC patients and Healthy Controls (HCs) in Iran. METHODS: A total of 40 UC patients and 40 healthy controls were included in the study. Saliva samples were collected and analyzed for the presence of B. fragilis and ETBF using real-time polymerase chain reaction (PCR). RESULTS: B. fragilis was more prevalent in HCs (70%) than UC patients (67.5%), but not significantly (p = 0.809). ETBF was significantly more prevalent in UC patients (50%) than HCs (10%) (p < 0.0001). The mean count of B. fragilis was higher in UC patients, but not significantly (p = 0.47). However, the mean count of ETBF was significantly higher in UC patients (p = 0.000089). In terms of gender, the number of B. fragilis in women was not significant (p = 0.16), but the number of ETBF was significantly higher in women with UC (p = 0.000458). For men, no significant differences were observed. CONCLUSIONS: The present study suggest a higher prevalence of B. fragilis observed in UC patients compared to HCs. Further research is needed to confirm these findings and explore potential mechanisms underlying this association.

Antimicrobial photodynamic effect of the photosensitizer riboflavin, alone and in combination with colistin, against pandrug-resistant Pseudomonas aeruginosa clinical isolates.

INTRODUCTION: Development of multi-, extensively-, and pandrug-resistant (MDR, XDR, and PDR) strains of Pseudomonas aeruginosa remains a major problem in medical care. The present study evaluated the effect of antimicrobial photodynamic therapy (aPDT) as a monotherapy and in combination with colistin against P. aeruginosa isolates. METHODS: Two P. aeruginosa isolates recovered from patients with respiratory tract infections were examined in this study. Minimum inhibitory concentration (MIC) of colistin was determined by the colistin broth disk elution (CBDE) and the reference broth microdilution (rBMD) methods. aPDT was performed using the photosensitizer (Ps) riboflavin at several concentrations and a light-emitting diode (LED) emitting blue light for different irradiation times with or without colistin at 1/2 × MIC concentration. RESULTS: Both PA1 and PA2 isolates were identified as colistin-resistant P. aeruginosa with a MIC ≥4 µg/mL by the CBDE and MICs of 512 µg/mL and 256 µg/mL, respectively, by the rBMD. In aPDT, neither riboflavin nor LED light alone had antibacterial effects. The values of colony forming units per milliliter (CFU/mL) in both isolates were significantly reduced by LED + Ps treatments in a time-dependent manner (LED irradiation time) and dose-dependent manner (Ps concentration). In comparison with control, treatment with Ps (50 µM) + LED (120 s) and Ps (100 µM) + LED (120 s) resulted in 0.27 log10 CFU/mL and 0.43 log10 CFU/mL reductions in PA1, and 0.28 log10 CFU/mL and 0.34 log10 CFU/mL reductions in PA2, respectively, (P < 0.01). The best results were obtained after the combination of aPDT followed by colistin, which increased bacterial reduction, resulting in a 0.41-0.7 log10 CFU/mL reduction for PA1 and 0.35-0.83 log10 CFU/mL reduction for PA2 (P = 0.001). CONCLUSIONS: This study suggests the potential implications of aPDT in combination with antibiotics, such as colistin for treatment of difficult-to-treat P. aeruginosa infections.

Cross-reactivity between Mycobacterium avium subspecies paratuberculosis 4027 peptide and Human IRF5 may contribute to Multiple Sclerosis in Iranian patients.

Background: The etiology of Multiple sclerosis (MS) is complicated and can be affected by several environmental factors, such as Mycobacterium avium subspecies paratuberculosis (MAP) infection in genetically predisposed individuals. The link between MAP and MS depends on host genetic and epigenetic aspects and population-based features that require further investigation. We aimed to study the possible role of MAP in triggering MS using molecular and serological methods. Materials and methods: This case-control study examined 200 blood samples (100 MS patients and 100 HCs) to search for the MAP-specific IS900 gene. In addition, ELISA was conducted to determine the humoral response against MAP_402718-32 and its human IRF5424-434 peptide homolog. Results: The frequency of MAP detection based on the molecular method in MS patients and HCs was 48 % and 13 %, respectively (p < 0.0001). The presence of antibodies against MAP_402718-32 and IRF5424-434 was 55 % and 65 % in MS patients versus 9 % and 7 % in HCs, respectively (p < 0.0001). A good correlation was observed between MAP_4027 and IRF5 antibodies (r = 0.5782, p < 0.0001), indicating that the same antibodies recognized common peptide epitopes. Conclusion: Our research revealed a significant association between MAP and MS, highlighting the possible role of MAP as an important infection trigger factor of MS. It is hypothesized that cross-reactivity between MAP4027 and IRF5 may dysregulate immune homeostasis.

Detection of Mycobacterium avium Subspecies paratuberculosis in the Blood of Patients with Rheumatoid Arthritis by Using Serological and Molecular Techniques.

The role of Mycobacterium avium subspecies paratuberculosis (MAP) in triggering rheumatoid arthritis (RA) could be a population-specific phenomenon. This study explored the relationship between MAP and RA using serological and molecular techniques; In this case-control study, 239 Iranian participants, including 120 RA patients and 119 controls, were enrolled. The indirect ELISA was designed to diagnose antibodies against MAP3865c125-133 and Zinc transporter 8 (ZnT8)178-186. The Nested-Polymerase Chain Reaction (PCR) detected MAP in blood; The frequency of MAP in RA patients and controls was 31.9% and 12.5%, respectively (P = 0.002). The antibodies against MAP3865c125-133 and ZnT8178-186 were 42.9% and 37% in RA patients and 14.2% and 11.7% in the controls, respectively (P < 0.0001). Interestingly, positive ELISA results in previously diagnosed (PD) RA were more common than newly diagnosed (ND) RA patients (P < 0.05).; The findings showed a higher frequency of MAP and its antibodies in the RA patients than in the controls. This data indicated MAP as one of RA's predisposing factors. Also, this first report implies the high positivity of MAP in Iranian RA patients.

Evaluation of Mutations Related to Streptomycin Resistance in Mycobacterium tuberculosis Clinical Isolates.

Drug resistance to streptomycin in the clinical isolates of Mycobacterium tuberculosis (MTB) needs special consideration. It can mostly be caused by mutations in four genes with the names rpsL, rrs, gidB, and whiB7. The main objective of this study was the evaluation of the type and frequency of mutations in these mentioned genes using the PCR-sequencing method. This study was performed on 15 streptomycin-resistant and five streptomycin-sensitive isolates. Among resistant isolates, 11 samples contained mutations in codon 43 of the rpsL gene, which caused the lysine to be converted to arginine. Additionally, all of the isolates had mutations in the gidB. Missense mutations in codons 92 and 20 of this gene result in the amino acids Glutamic acid or Arginine being changed to Aspartic acid or Proline, respectively. No mutations in the rrs or whiB7 were found in any of the samples. Simultaneous mutations of rpsL and gidB were found in 10 isolates, the majority of which were Beijing strain. The results showed that the mutations of rpsL and gidB genes are mostly responsible for the streptomycin resistance in the evaluated MTB isolates. Furthermore, the discovery of dual mutations in Beijing strains highlights the strain's considerable potential for developing Tuberculosis drug resistance.

Mycobacterium avium subsp. paratuberculosis and Hashimoto's thyroiditis: Is MAP the trigger?

Hashimoto's thyroiditis (HT) is an autoimmune disorder of the thyroid gland that can cause hypothyroidism. As HT is a multifactorial disorder, activation of immune responses in genetically predisposed individuals exposed to some environmental factors can contribute to it. Microorganisms, as environmental factors, including Mycobacterium avium ssp. paratuberculosis (MAP) by molecular mimicry, can be important in this autoimmune disorder. This study aimed to investigate the association between MAP and HT. This case-control study included 110 participants consisting of 60 HT patients and 50 healthy controls (HCs). Blood samples were collected. Nested PCR of the IS900 gene determined the presence of MAP DNA. The enzyme-linked immunosorbent assay (ELISA) was designed to identify antibodies (Abs) against the MAP3865c epitope, which has a homologous sequence with ZnT8 in the sera. The demographic information of all participants was recorded. Anti-TG, anti-TPO, TSH, anemia, and ruminant exposure were higer in HT patients than in the HCs (p < 0.05). MAP IS900 was detected significantly more in the patients (46.6% consisting of 30, 8.3, and 8.3% in clinical, subclinical, and unknown) than in the HCs (14%). The sera showed a remarkable frequency of reactivity against MAP3865c in the patients (38.3%) in comparison to the HCs (10%) (p = 0.0001). Furthermore, a significantly higher rate of livestock contact and traditional dairy consumption was found in individuals with MAP or anti-MAP3865c Abs positive result (p < 0.05). This study suggests a possible link between MAP and HT. These findings indicated that MAP frequency was not statistically different in the severity of HT and its shift into the clinical and subclinical forms; therefore, it could be assumed that MAPs are the initiators of the process. The results imply on a possible zoonosis transmission route of MAP from livestock products to humans. Further research is needed to confirm these results in larger groups of HT patients.

Comparison of hspX gene sequence in the Beijing and non-Beijing Mycobacterium tuberculosis.

PURPOSE: The pathogenicity of various lineages of Mycobacterium tuberculosis (MTB) is different. This could be due to the difference in survival ability within the host macrophage. The alpha crystalline secretion protein, a product of the hspx gene, is one of the bacterial protection factors in these stressful situations. The Beijing family, part of the East Asian lineage, was reported to be more virulent. Regarding the importance of this protein in pathogenicity, this study was conducted to investigate the polymorphism of the hspx gene in Beijing family compared to non- Beijing strains. METHOD: DNA of 50 MTB isolates were extracted by boiling method. The existence of hspx gene was determined using PCR-specific primer and finally PCR product was sequenced to examine the polymorphism in both direct and reverse directions. Sequencing results were aligned by chromas software. RESULTS: The hspx gene was detected in all of the Beijing and non-Beijing isolates. The polymorphism in the sequences of this gene were not observed in all of the MTB isolates. DISCUSSION: This study indicated that hspx gene is protected. Also it has showed that lineage type was not related to the sequence of hspX gene, but the expression of this protein may be different, which requires further studies.

Prevalence and Mechanisms of Carbapenem Resistance in Klebsiella pneumoniae and Escherichia coli: A Systematic Review and Meta-Analysis of Cross-Sectional Studies from Iran.

Introduction: Carbapenem-resistant Enterobacteriaceae (CRE) represents an urgent threat worldwide. We aimed to investigate the frequency of carbapenem-resistant Klebsiella pneumoniae and Escherichia coli in Iran. Materials and Methods: PubMed/Medline, Embase, Scopus, Web of Sciences, and Iranian databases were searched to find potentially relevant articles. Statistical analyses were performed using STATA version 14. Results: Forty-nine studies fulfilled the inclusion criteria. The pooled rates of resistance to carbapenem in K. pneumoniae and E. coli were 24.0% (95% confidence interval [CI] 18.0-31.0) and 5.0% (95% CI 2.0-8.0), respectively. blaOXA-48 gene was the most common cause of carbapenem resistance in K. pneumoniae and E. coli. Conclusions: CRE is prevalent in Iran, which confers the importance of strength prevention and control measures.

Antibiotic therapy success rate in pulmonary Mycobacterium avium complex: a systematic review and meta-analysis.

Objectives: The incidence of Mycobacterium avium complex (MAC) pulmonary disease is increasing worldwide. We conducted a systematic review and meta-analysis to determine the treatment success rate of antibiotic therapy in MAC pulmonary disease and evaluate the effectiveness of aminoglycoside-containing regimens.Methods: We searched literature between 1 January 1980 to 19 June 2019. Studies with diagnosis criteria based on the current guidelines that reported treatment outcomes were included. We defined treatment success as the achievement of culture conversion and completion of the planned treatment without relapse while on treatment.Results: We retrieved 45 studies including 3862 patients. The estimated pooled treatment success rate was 68.1% [95% confidence interval (CI) 64.7-71.4%]. Based on the Cochrane tool, the included studies had a low risk of bias. Forty-two studies reported macrolide-containing regimens, while 6 studies included aminoglycoside-containing regimens. Macrolide-containing regimens led to better treatment success rates comparing to non-macrolide-containing regimens; 69% vs 58.5%, respectively. Treatment duration of 12 months or more showed better results.Conclusion: Poor treatment success rate of MAC pulmonary disease calls for more randomized clinical trials designed based on consensus definitions of the disease diagnosis and treatment. New drugs with a better adherence rate need to be developed.Systematic Review Registration: PROSPERO (pending registration ID: 151674).

Prevalence and Mechanisms of Carbapenem Resistance in Acinetobacter baumannii: A Comprehensive Systematic Review of Cross-Sectional Studies from Iran.

Introduction: Carbapenem-resistant Acinetobacter baumannii (CRAB) is recognized to be among the most difficult antimicrobial-resistant gram-negative bacilli to control and treat. An understanding of the epidemiology of CRAB and the mechanisms of resistance to carbapenems is necessary to develop strategies to curtail their spread. Methods: Electronic databases were searched from January 1995 to December 2017 for all studies, which: (1) provide data on the frequency and antibiotic resistance profile of the isolated A. baumannii and (2) describe the mechanisms of carbapenem resistance in detail. Results: Sixty-eight studies were found referring to mechanisms of carbapenem resistance in clinical isolates of A. baumannii, and 56 studies were found referring to the frequency of CRAB. The pooled frequency of carbapenem resistance was 85.1% (95% confidence interval [CI]: 82.2-88.1) in 8,067 clinical isolates of A. baumannii. Resistances due to blaOXA23 (55.3%), blaOXA24 (41.4%), and blaOXA58 (5.2%) genes were the most prevalent reported mechanisms of resistance to carbapenem, respectively. Conclusions: Our data warn that CRAB will rise if the current situation remains uncontrolled. Better control infection strategies and antibiotic managements, particularly in the health care systems, are needed to limit the spread of this pathogen.

Molecular detection of Campylobacter jejuni in patients with Crohn's disease in Iran.

Background: Crohn's disease is one of the most significant intestinal disorders and is known as inflammatory bowel disease; Campylobacter spp. are one of the leading causes of bacterial gastroenteritis in humans. Methods: In this study, 60 tissue samples, including 30 cases with Crohn's disease and 30 cases with no inflammatory bowel disease, were collected. Patients were referred to Taleghani hospital and Behboud clinic between March 2015 and May 2016. Biopsies were used for DNA extraction and assessment of Campylobacter jejuni in patients with Crohn's disease and controls using polymerase chain reaction and quantitative real-time polymerase chain reaction. All positive amplified fragments were sequenced. The gene encoding 16S rRNA, specific to Campylobacter genus, was amplified. Results: The results were positive for Campylobacter genus in patients with Crohn's disease compared to healthy individuals. The quantitative real-time PCR showed a significantly higher prevalence of Campylobacter jejuni, particularly in hippurate hydrolase in tissue specimens of patients with Crohn's disease compared to control group. The correlation between Campylobacter jejuni and diarrhea symptoms in patients with Crohn's disease and controls was investigated. One positive case of Campylobacter jejuni found in patients without diarrhea was compared with 13 patients with diarrhea. Conclusion: The present study demonstrated the alarmingly high rate of Campylobacter jejuni prevalence in Crohn's disease patients with diarrhea symptoms. However, further investigation is needed to determine the possible causing factors of this disease.

Latent tuberculosis infection in transplant candidates: a systematic review and meta-analysis on TST and IGRA.

INTRODUCTION: The diagnostic accuracy of interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST) for latent tuberculosis infection (LTBI) in transplant candidates is uncertain. METHODS: Pubmed, Embase and Cochrane library were searched to identify relevant studies. Quality of included studies was assessed with RevMan5 software (via GUADAS2 checklist). Accuracy measures of IGRAs and TST assays (sensitivity, specificity and others) were pooled with random effects model. Data were analyzed by STATA and Meta-DiSc. RESULTS: Twenty-eight studies were selected for full review, and 16 were included in the final analysis. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) for TST were 46% [95% confidence interval (CI) 38-54%], 86% (95% CI 75-93%), 46.3% (95% CI 40-52), 88.7% (95% CI 87-89), 3.3 (95% CI 1.6-6.4), 0.63 (95% CI 0.52-0.77) and 5 (95% CI 2-12), respectively. For QFT-G, the pooled sensitivity, specificity, PPV, NPV, PLR, NLR, and DOR were 58% (95% CI 41-73%), 89% (95% CI 77-95%), 72.7% (95% CI 68-76), 80.6% (95% CI 78-82), 5.3 (95% CI 2.0-14.0), 0.47 (95% CI 0.30-0.75) and 11 (95% CI 3-46), respectively. Likewise, for T-SPOT.TB, the pooled sensitivity, specificity, PPV, NPV, PLR, NLR, and DOR were 55% (95% CI 40-70%), 92% (95% CI 87-95%), 60.4% (95% CI 47-72), 90.2% (95% CI 86-92), 6.7 (95% CI 4.0-11.1), 0.52 (95% CI 0.31-0.85) and 16 (95% CI 7-37), respectively. CONCLUSIONS: IGRAs were more sensitive and specific than the TST with regard to the diagnosis of LTBI in the transplant candidates. They have added value and can be complementary to TST.

Enterotoxigenic Bacteroides fragilis: A Possible Etiological Candidate for Bacterially-Induced Colorectal Precancerous and Cancerous Lesions.

Enterotoxigenic Bacteroides fragilis (ETBF) produces Bacteroides fragilis toxin (BFT), which is associated with acute diarrheal, inflammatory bowel disease, and colorectal cancer (CRC). In experimental models, ETBF has been shown to contribute to colon carcinogenesis. The present study was conducted to investigate mucosal colonization of ETBF in the colon to find a possible association between the presence of ETBF and precancerous and cancerous lesions. The mucosal biopsies of involved sites were obtained from 68 patients with precancerous and cancerous lesions and 52 healthy controls (HC). The samples were cultured on Bacteroides Bile Esculin agar. Then, specific primers were designed to detect B. fragilis and bft gene using quantitative real-time PCR, and the possible links of ETBF with clinicopathological characteristics was evaluated. Also real-time PCR was performed to detect the bft gene subtypes. Bacteroides fragilis was detected in 51% of the patients and 48% of HCs cultures. The 16SrRNA gene was found to be present in 63 and 81% of the patients and HCs' samples, respectively. Moreover, the bft gene was detected in 47 and 3.8% of the patients and HCs, respectively. Also, B. fragilis was significantly more abundant in the patients' samples compared to those of HCs. In the patient group, higher odds ratio (OR) of ETBF was significantly associated with serrated lesions and adenoma with low-grade dysplasia. The bft1 gene was the most prevalent subtype of bft gene, followed by the bft2 gene. This was the first study in Iran to demonstrate increased positivity of ETBF in patients with precancerous and cancerous lesions. In this study, the bft gene was found to be associated with CRC, especially in the patients with precancerous lesions and initial carcinogenic lesions. Moreover, the results suggest that mucosal BFT exposure is common and could be a risk factor and a screening marker for developing CRC.

High genetic diversity among Mycobacterium tuberculosis strains in Tehran, Iran.

INTRODUCTION: Tuberculosis (TB) still remains an important public health problem in Iran. The genotyping of Mycobacterium tuberculosis isolates is expected to lead to a better understanding of M. tuberculosis transmission in Tehran, the most populated city of Iran. MATERIALS AND METHODS: A total of 2300 clinical specimens were obtained from TB suspected patients who were referred to a TB center in Tehran from Jan 2014 to Dec 2016. Identification was performed using both conventional and molecular methods. The presence of resistance to rifampicin was examined by the GeneXpert MTB/RIF. The standard 15-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing method was applied to genotype of clinical isolates. RESULTS: Of 2300 specimens, 80 isolates were identified as M. tuberculosis by using biochemical and molecular tests. Of 80 M. tuberculosis isolates, 76 (95%) had unique genotypic profiles and 4 (5%) shared a profile with one or more other strains. Based on single loci variation (SLV) 4 clonal complexes were observed. NEW-1 was found to be the most predominant lineage (22.5%) followed by West African (1.25%), Central Asian (CAS)/Delhi (1.25%), Bovis (1.25%), H37Rv (1.25%) and multiple matches (1.25%). Loci MIRU10, MIRU26, MTUB21 and QUB26 were found as highly discriminative. No mutation was detected in the hotspot region of rifampicin by using GeneXpert MTB/RIF. CONCLUSIONS: Our study findings show that there was considerable genotypic diversity among M. tuberculosis isolates in Tehran. The 15-locus MIRU-VNTR showed high HGDI and could be used as a first-line genotyping method for epidemiological studies.

Detection of enterotoxigenic Bacteroides fragilis in patients with ulcerative colitis.

PURPOSE: Ulcerative colitis (UC) as a type of inflammatory bowel disease (IBD), presumed to occur as a consequence of increased immune responses to intestinal microbiota in genetically susceptible individuals. Enterotoxigenic Bacteroides fragilis (ETBF) strains are important intestinal bacteria that can be involved in IBD. The aim of this study was to design a quantitative assay for detection of B. fragilis and ETBF and also to find their association with UC. METHODS: Ninety-five biopsies were collected from patients with UC (n = 35) and with no IBD (nIBD, n = 60). All the specimens were cultured in Bacteroides bile esculin agar medium. Specific primers and probes were designed for quantitative real-time PCR (QRT-PCR) based on 16S rRNA and bft genes sequences of ETBF. RESULTS: The bft genes were detected in 51.4% of UC samples and 1.6% of nIBD samples, respectively. In UC patients, 37.1% of samples with diarrhea and 11.4% of samples without diarrhea, harbored the bft gene. Mean value of the number of ETBF with bft gene in UC and nIBD samples were 4.46 ×Y 102 and 1.96, respectively. Likewise these result for 16S rRNA gene in UC and nIBD samples were 2.0 × 103 and 8.4 × 103, respectively. CONCLUSIONS: There was no significant association between presence and numbers of 16S rRNA gene of B. fragilis and UC. ETBF was detected more in UC specimens and biopsies of UC patients with diarrhea than in the control group. These data demonstrated that ETBF is associated with development of UC and as a causative agent for the development of diarrhea in these patients.

Mycobacterium avium subsp. paratuberculosis and associated risk factors for inflammatory bowel disease in Iranian patients.

BACKGROUND: Inflammatory bowel disease (IBD) is described as a relapsing condition with high morbidity and uncertain complex pathogenesis. The association of Mycobacterium avium ssp. paratuberculosis (MAP) with Crohn's disease (CD) in human has been debated for decades, however there is no confirmed data to verify such relations in Iran. The aim of this study was to investigate risk factors and a possible role of MAP in Iranian patients with CD. METHODS: Anti-MAP antibodies were detected in serum of IBD patients and subjects without IBD (nIBD) through ELISA; MAP DNA and viable MAP cells were identified in patients' biopsies through nested PCR and direct culture methods, respectively. Principal component analysis (PCA) was used to investigate the risk factors in relation to IBD and MAP infection. RESULTS: Positivity for IS900 PCR was detected in 64% (n = 18) of CD, 33% (n = 10) of ulcerative colitis (UC) and 9.7% (n = 6) of nIBD samples. Live MAP cells were isolated from biopsies of 2 CD patients only. Among 28 patients with CD, 46% (n = 13) and 39% (n = 11) were positive for antibodies against MAP3865c133-141 and MAP3865c125-133 peptides, respectively, whereas much lower seroreactivity was detected in UC subjects accounting for 3% (n = 1) for MAP3865c133-141 and 16.7% (n = 5) for MAP3865c125-133. A high immune reactivity to MAP epitopes among CD patients was positively correlated with consumption of fast food meals and IBD familiarity. For both CD and UC, breastfeeding period and consumption of fruit/vegetables presented negative correlation with the presence of anti-MAP antibodies. CONCLUSIONS: This study provided evidences that high prevalence of MAP DNA and anti-MAP antibodies in CD patients is significantly associated with the development of CD. Despite the role of several factors contributing to IBD, the presence of MAP DNA and anti-MAP antibodies in Iranian CD patients highlights a possible transmission of MAP from animal-derived products to humans.

MIRU-VNTR analysis of Mycobacterium tuberculosis from Tehran, Sistan-Baluchestan, Kermanshah and Hormozgan during 2014 and 2015.

Standard 15-locus Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat (MIRU-VNTR) typing of Mycobacterium tuberculosis (MTB) is a valuable instrumentation for TB control. Our knowledge about the genetic diversity of MTB and population structure of MTB circulating in Iran is limited. During 2014-2015, 98 MTB isolates were collected from the TB centers of four provinces of Iran. Isolates were genetically characterized using 15-locus based MIRU-VNTR typing. Ninety-five distinct mycobacterial interspersed repetitive unit MIRU-VNTR patterns were found among 98 isolates. 5 (5.1%) isolates grouped into 2 clusters and 93 (94.89%) isolates had a unique pattern. The HGDI was as high as 0.99 and 10 of loci were designated as highly discriminative. Clusters belonged to Tehran only. This indicates these patterns are rotating in Tehran. Unique patterns suggest that distribution of samples in each province and population differs. HGDI is higher than previous studies for MIRU-VNTR typing in Iran. We suggest MIRU-15 because it is a valid epidemiological background for clustering defined. Limited data is available on the genetic diversity and transmission dynamics of MTB in Iran. To examine the genetic diversity and transmission dynamics of MTB strains we genotyped a collection of isolates from four different parts of Iran. The method of 15-loci MIRU-VNTR demonstrated high discriminatory power and may be applied as a first-line genotyping instrumentation in investigating the molecular epidemiology of M. tuberculosis in Iran.

Genotyping of Mycobacterium tuberculosis Isolates from Hormozgan Province of Iran Based on 15-Locus MIRU-VNTR and Spoligotyping.

Background. Considering that Hormozgan province in Iran (southern part of Iran on the Persian Gulf) is among the areas with high prevalence of MDR-MTB and attracts so many sailors and tourists, genetic diversity of MTB isolates circulating in this part of Iran was evaluated. Pattern of TB transmission was also examined. Methods and Material. A total of 38 isolates of MTB were cultured from TB patients from Hormozgan province of Iran and standard MIRU-VNTR typing and spoligotyping were applied to genotype these isolates. Drug susceptibility testing was performed using proportion method. Results. There were 28 VNTR profiles comprising 5 clusters and 23 unique isolates compared to 21 spoligotyping profiles, which contained 9 clusters and 12 unique isolates. Latin American-Mediterranean (n = 9, 23.6%) was found to be the most predominant lineage. MIRU-VNTR analysis, with an HGDI of 0.975, was more discriminating than spoligotyping, which had an HGDI of 0.955. The estimated proportion of TB cases due to recent transmission was 26.3% and 44.7% by MIRU-VNTR and spoligotyping, respectively. The rates of monodrug resistance and MDR were 15.8% and 7.9%, respectively. Two of 3 MDR strains were found to be related to MIRU-VNTR and belonged to the same spoligotyping cluster characterized with T1/SIT53 genotype. Conclusions. The high genetic diversity among MTB isolates suggests that transmission occurred from different sources to this area. Reactivation of a priori, latent MTB infection was found to contribute mainly to TB cases in this geographic region.

Molecular characterization of Mycobacterium tuberculosis isolates from Tehran, Iran by restriction fragment length polymorphism analysis and spoligotyping.

INTRODUCTION Characterization of Mycobacterium tuberculosis (MTB) isolates by DNA fingerprinting has contributed to tuberculosis (TB) control. The aim of this study was to determine the genetic diversity of MTB isolates from Tehran province in Iran. METHODS MTB isolates from 60 Iranian and 10 Afghan TB patients were fingerprinted by standard IS6110-restriction fragment length polymorphism (RFLP) analysis and spoligotyping. RESULTS The copy number of IS6110 ranged from 10-24 per isolate. The isolates were classified into 22 clusters showing ≥ 80% similarity by RFLP analysis. Fourteen multidrug-resistant (MDR) isolates were grouped into 4 IS6110-RFLP clusters, with 10 isolates [71% (95% CI: 45-89%)] in 1 cluster, suggesting a possible epidemiological linkage. Eighteen Iranian isolates showed ≥ 80% similarity with Afghan isolates. There were no strains with identical fingerprints. Spoligotyping of 70 isolates produced 23 distinct patterns. Sixty (85.7%) isolates were grouped into 13 clusters, while the remaining 10 isolates (14.2%) were not clustered. Ural (formerly Haarlem4) (n = 22, 31.4%) was the most common family followed by Central Asian strain (CAS) (n = 18, 25.7%) and T (n = 9, 12.8%) families. Only 1strain was characterized as having the Beijing genotype. Among 60 Iranian and 10 Afghan MTB isolates, 25% (95% CI: 16-37) and 70% (95% CI: 39-89) were categorized as Ural lineage, respectively. CONCLUSIONS A higher prevalence of Ural family MTB isolates among Afghan patients than among Iranian patients suggests the possible transmission of this lineage following the immigration of Afghans to Iran.

Molecular characterization of mycobacterium tuberculosis isolates from Tehran, Iran by restriction fragment length polymorphism analysis and spoligotyping

Abstract: INTRODUCTION Characterization of Mycobacterium tuberculosis (MTB) isolates by DNA fingerprinting has contributed to tuberculosis (TB) control. The aim of this study was to determine the genetic diversity of MTB isolates from Tehran province in Iran. METHODS MTB isolates from 60 Iranian and 10 Afghan TB patients were fingerprinted by standard IS6110-restriction fragment length polymorphism (RFLP) analysis and spoligotyping. RESULTS The copy number of IS6110 ranged from 10-24 per isolate. The isolates were classified into 22 clusters showing ≥ 80% similarity by RFLP analysis. Fourteen multidrug-resistant (MDR) isolates were grouped into 4 IS6110-RFLP clusters, with 10 isolates [71% (95% CI: 45-89%)] in 1 cluster, suggesting a possible epidemiological linkage. Eighteen Iranian isolates showed ≥ 80% similarity with Afghan isolates. There were no strains with identical fingerprints. Spoligotyping of 70 isolates produced 23 distinct patterns. Sixty (85.7%) isolates were grouped into 13 clusters, while the remaining 10 isolates (14.2%) were not clustered. Ural (formerly Haarlem4) (n = 22, 31.4%) was the most common family followed by Central Asian strain (CAS) (n = 18, 25.7%) and T (n = 9, 12.8%) families. Only 1strain was characterized as having the Beijing genotype. Among 60 Iranian and 10 Afghan MTB isolates, 25% (95% CI: 16-37) and 70% (95% CI: 39-89) were categorized as Ural lineage, respectively. CONCLUSIONS A higher prevalence of Ural family MTB isolates among Afghan patients than among Iranian patients suggests the possible transmission of this lineage following the immigration of Afghans to Iran.