Prevalence of rapidly growing mycobacteria (RGM) in Iran: Systematic review and meta-analysis

AbstractBackgroundThe infections due to rapidly growing mycobacteria (RGM) are becoming an important health problem in many countries in the world. Globally, an increase in RGM infections is being reported from several regions worldwide. However, there is limited information about the prevalence of these kinds of organisms in Iran.MethodsThe relevant data of the prevalence of RGM were retrieved by searching several databases, such as PubMed, Web of Science, Cochrane Library, Embase, Scopus, Iranmedex, and Scientific Information Database. Meta-analysis was performed by Comprehensive Meta-Analysis (V2.0, Biostat) software.ResultsThe meta-analyses showed that the Mycobacterium fortuitum (22.7% [95% CI 16.1–30.9]), Mycobacterium abscessus (14.0% [95% CI 6.4–27.8]) and Mycobacterium chelonae (7.6% [95% CI 2.8–18.8]) were the most prevalent RGM among the conducted studies in Iran.ConclusionsThe relatively high prevalence of RGM underlines the need for greater enforcement of infection control strategies. Establishment of appropriate diagnostic criteria and management guidelines for diseases caused by RGM and expanding the number and quality of regional reference laboratories may facilitate more accurate action for prevention and control of this kind of bacteria

Association of IFN-γ and P2X7 Receptor Gene Polymorphisms in Susceptibility to Tuberculosis Among Iranian Patients

Interferon-gamma (IFN-γ) and P2X7 receptor are crucial for host defence against mycobacterial infections. Recent studies have indicated that IFN-γ, IFN-γ receptor 1 (IFN-γR1) andP2X7 gene polymorphisms are associated with susceptibility to pulmonary tuberculosis (TB). However, the relationship between IFN-γ and P2X7 polymorphism and TB susceptibility remains inconclusive in Iranian population. For this reason, single nucleotide polymorphisms (SNPs) in IFN-γ (G+2109A), IFN-γR1 (G-611A) and P2X7 genes (at –762, 1513 position) in patients (n = 100) were assessed using PCR-RFLP. Data were analysed with SPSS version 18. For the 2109 loci of IFN-γ gene, the frequency of mutant alleles between patients and controls were not statistically significant. However, there was a significant difference between the TB patient and controls for –611 alleles of IFN-γR1 (P = 0.01). Additionally, the frequency of P2X7 gene polymorphisms (SNP-762 and 1513) between patients and controls was statistically significant. In conclusions, our study revealed a significant association of IFN-γR1 and P2X7 genes polymorphisms with risk of developing TB in Iranian population

Association of P2X7 Gene Polymorphisms with Chronic Hepatitis B Virus Infection in Duhok, Iraqi Kurdistan

Host and viral factors are important determinants in the pathogenesis of chronic HBV infection. To date, polymorphisms in several genes such as tumor necrosis factor-alpha, tripartite motif-containing 22, have been found to contribute to the risk of developing chronic HBV infection. The polymorphism in P2X7 gene has recently been demonstrated to be associated with susceptibility or resistance to infectious diseases. However, still no clear association between P2X7 gene and chronic HBV infection has been reported in the literature. Hence, this study aimed to investigate whether two polymorphisms of P2X7 (1513 and -762) genes confer susceptibility to chronic HBV infection. In a case control study, single nucleotide polymorphisms (SNPs) in P2X7 (1513, -762) genes were assessed using allele-specific PCR and PCR- RFLP. Thereafter, frequency of the genotypes and alleles in patients and control groups were compared and analyzed. For the 1513 loci, the heterozygosity (AC) was higher in patients (73; 50.0%) than controls (14; 23.3%) [P = 0.001, OR 3.286, 95% CI 1.587-6885]. Furthermore, we found that the C allele was a risk factor for predisposition to chronic HBV infection (P = 0.006, OR 2.247, 95% CI 1.207-4.231). For the -762 loci, there were no significant statistical differences between the case and control groups in the genotype and allele frequencies (P > 0.05). In conclusion, in our study population, the P2X7 gene polymorphisms could be associated with susceptibility to chronic HBV infection

First insight into the drug resistance pattern of Mycobacterium tuberculosis in Dohuk, Iraq: Using spoligotyping and MIRU-VNTR to characterize multidrug resistant strains

SummaryThe objectives of this study were to determine drug resistance pattern in new and previously treated tuberculosis (TB) patients, to assess function of TB control program, and to characterize multidrug resistant TB (MDR-TB) by molecular fingerprinting methods. Anti-micorbial susceptibility testing (AST) to the first line anti-TB drugs was performed on Löwenstein–Jensen (middlebrook 7H10) medium according to the proportion method. Molecular fingerprinting of all MDR strains was performed by spoligotyping and MIRU-VNTR. Mycobacterium tuberculosis strains were isolated from 53 Iraqi patients with pulmonary TB. Thirty eight patients (71.7%) tested cases, and 15 (28.3%) were previously treated. Four of the 38 new cases (10.5%) had resistant, of which 3 (7.9%) were MDR. Eight (53.3%) of the 15 previously treated patients had resistant strains, of which 7 (46.7%) were MDR. Spoligotyping of MDR strains showed CAS family (40%) as the predominant genotype. Using MIRU-VNTR typing, all isolates had a unique profile. MDR-TB prevalence is higher among previously treated patients than among the new cases. The many drug resistant strains, in absence of evidence of recent transmission and in combination with the many previously treated cases, highlight the need for an improved control program, coupled with a need to improve detection rate and early diagnosis of MDR-TB

HIV and tuberculosis trends and survival of coinfection in a referral center in Tehran: A 12-year study

AbstractObjective/backgroundThe risk of mortality and morbidity among tuberculosis (TB) and human immunodeficiency virus (HIV) coinfected patients is significantly higher than that of patients infected with TB alone. The aim of this study was to evaluate the survival of TB-HIV patients in a TB-referral center during a 10-year follow-up.MethodsAll TB-HIV patients in our referral center were enrolled in the study from 2003 to 2014, and patients were divided into two groups: HIV-TB patients without a history of TB treatment (new cases of TB) and HIV-TB patients with a history of TB treatment. Both groups were treated based on World Health Organization TB-treatment guidelines, and multivariate analysis was performed to evaluate risk factors of all-cause mortality.ResultsDuring the study, 22 HIV-TB patients with a history of TB treatment and 263 HIV-TB patients with newly diagnosed TB were included. Baseline demographic and clinical characteristics were similar, except that miliary TB (98% vs. 2%) and mortality (97% vs. 3%; p=0.06) were more likely in HIV patients with newly diagnosed TB. During TB treatment and subsequent follow-up, two patients did not respond to treatment and 92 (32.3%) patients died, whereas the cure rate was 60%. Pneumothorax [hazard ratio (HR): 3.17], coinfection (herpes zoster, toxoplasmosis, cytomegalovirus infection, Pneumocystis jiroveci, candidiasis, and other opportunistic infection; HR: 1.75), CD4<100cells/mL (HR: 1.96), thrombocytopenia (HR: 2.29), and lack of treatment with antiretroviral agents (ART; HR: 2.82) were significantly associated with all-cause mortality according to multivariate analysis.ConclusionOur retrospective review of coinfected TB-HIV patients hospitalized in Tehran showed that the management and monitoring of coinfection, pneumothorax and other adverse effects, as well as early initiation of ART, improved patient survival

Populations of latent Mycobacterium tuberculosis lack a cell wall: Isolation, visualization, and whole-genome characterization

AbstractObjective/BackgroundMycobacterium tuberculosis (MTB) causes active tuberculosis (TB) in only a small percentage of infected people. In most cases, the infection is clinically latent, where bacilli can persist in human hosts for years without causing disease. Surprisingly, the biology of such persister cells is largely unknown. This study describes the isolation, identification, and whole-genome sequencing (WGS) of latent TB bacilli after 782days (26months) of latency (the ability of MTB bacilli to lie persistent).MethodsThe in vitro double-stress model of latency (oxygen and nutrition) was designed for MTB culture. After 26months of latency, MTB cells that persisted were isolated and investigated under light and atomic force microscopy. Spoligotyping and WGS were performed to verify the identity of the strain.ResultsWe established a culture medium in which MTB bacilli arrest their growth, reduce their size (0.3–0.1μm), lose their acid fastness (85–90%) and change their shape. Spoligopatterns of latent cells were identical to original H37Rv, with differences observed at spacers two and 14. WGS revealed only a few genetic changes relative to the already published H37Rv reference genome. Among these was a large 2064-bp insertion (RvD6), which was originally detected in both H37Ra and CDC1551, but not H37Rv.ConclusionHere, we show cell-wall free cells of MTB bacilli in their latent state, and the biological adaptation of these cells was more phenotypic in nature than genomic. These cell-wall free cells represent a good model for understanding the nature of TB latency

The Recent-Transmission of Mycobacterium tuberculosis Strains among Iranian and Afghan Relapse Cases: a DNA-fingerprinting using RFLP and spoligotyping

<p>Abstract</p> <p>Background</p> <p>Relapse of tuberculosis (TB) may develop as the result of reactivation of the endogenous primary infection, or as a result of a exogenous reinfection. This survey evaluated the rate of reactivation versus recent transmission among Iranian and Afghan relapse cases.</p> <p>Methods</p> <p>The sputum specimens were digested, examined microscopically for acid-fast bacilli, and inoculated into Löwenstein-Jensen slants by standard procedures. Thereafter, the susceptibility and identification tests were performed on culture positive specimens. Subsequently, the strains that were identified as <it>Mycobacterium tuberculosis </it>(258 isolates) were subjected to IS6110 restriction fragment length polymorphism (RFLP) and spoligotyping. Additional patient's information was collected for further epidemiological analysis. Patients whose isolates had identical genotyping patterns were considered a cluster with recent transmission episode.</p> <p>Results</p> <p>Out of 258 available isolates, 72(28%) had multi-drug resistant (MDR-TB) in ratio and 42 (16.2%) had other resistant. Notably, 38 of MDR-TB cases (52%) were isolated from Afghan patients. By IS6110-RFLP typing method, 65 patients (25%) were clustered in 29 clusters. In cluster cases, the intra-community transmissions between Iranian and Afghan patients were 41%. All MDR-TB patients in clusters had either Haarlem I or Beijing characteristic. The risk factors like sex, family history, close contact, living condition, PPD test result and site of TB infection were not associated with clustering. Although, the MDR-TB strains were more frequent in non-cluster cases (31%) than cluster one(18%) (P < 0.05). Majority of <it>M. tuberculosis </it>strains isolated from non-cluster cases were belong to EAI3 (51; 30%) and CASI(32;18.6%) superfamilies.</p> <p>Conclusion</p> <p>During the studied period, reactivation of a previous infection remain the more probable cause of recurrence. Although, the evidence of intra- community transmission between Iranian and Afghan TB cases, highlighted the impact of afghan immigrants in national tuberculosis control program (NTP) of Iran.</p