Low Levels of Extensively Drug-resistant Tuberculosis among Multidrug Resistant Tuberculosis Isolates and Their Relationship to Risk Factors: Surveillance in Tehran, Iran; 2006 to 2014

OBJECTIVES: Extensively drug-resistant tuberculosis (XDR-TB) is more expensive and difficult to treat than multidrug-resistant tuberculosis (MDR-TB), and outcomes for patients are much worse; therefore, it is important that clinicians understand the magnitude and distribution of XDR-TB. We conducted a retrospective study to compare the estimated incidence of and risk factors for M/XDR-TB with those of susceptible TB controls. METHODS: Sputum culture and drug susceptibility testing (DST) were performed in patients with known or suspected TB. Strains that were identified as MDR were subjected to DST for second-line drugs using the proportion method. RESULTS: Among 1,442 TB patients (mean age, 46.48 ± 21.24 years) who were culture-positive for Mycobacterium tuberculosis, 1,126 (78.1%) yielded isolates that were resistant to at least one first-line drug; there were 33 isolates (2.3%) of MDR-TB, of which three (0.2%) were classified as XDR-TB. Ofloxacin resistance was found in 10 (0.7%) isolates. Women were 15% more likely than men to yield M/XDR-TB isolates, but this difference was not significant. In a multivariate analysis comparing susceptible TB with X/MDR-TB, only one variable—the number of previous treatment regimens—was associated with MDR (odds ratio, 1.06; 95% confidence interval, 1.14–21.2). CONCLUSION: The burden of M/XDR-TB cases is not sizeable in Iran. Nonetheless, strategies must be implemented to identify and cure patients with pre-XDR-TB before they develop XDR-TB. Our results provide a greater understanding of the evolution and spread of M/XDR-TB in an environment where drug-resistant TB has a low incidence.

[Evaluation of serum angiotensin converting enzyme [ACE] activity in type 1 Gaucher's patient and its relationship to ACE gene insertion/deletion in intron 16]

Background: Gaucher's disease is an autosomal recessive disease which is the result of mutations in the P glucocerebrosidase gene. The aim of this study was to evaluate activity level of ACE enzyme Iranian patients with Gaucher's disease type I, and also polymorphism I/D in intron 16 of ACE gene, as a marker in diagnosis and monitoring of disease

Materials and methods: The experiments were performed on 29 patients [mean age of 10.04 years] and 60 healthy subjects [mean age of 7.31 years]. Procedures included DNA extraction from blood, detection of polymorphism I/D by PCR and evaluation of activity level of ACE enzyme

Results: The mean of ACE activity was 231.07 U/L which was increased 4 times than normal status [56.03 U/L]. Evaluation of polymorphism I/D of the 29 patients showed t6 [20.7%] II, 9 [31%] DD and 14[48.3%]ID[p<0.05]

Conclusion: According to the results, the measurement of the ACE activity levels can be used as cofactors in diagnosis and as well as an important factor in the monitoring of treatment. Polymorphism I/D with respect to the role of the ACE activity can be effective in increasing the specificity of the experiments

Distribution and diversity of hmw1A among invasive nontypeable Haemophilus influenzae isolates in Iran

Background: The pathogenesis of nontypeable Haemophilus influenzae [NTHi] begins with adhesion to the rhinopharyngeal mucosa. Almost 38-80% of NTHi clinical isolates produce proteins that belong to the High Molecular Weight [HMW] family of adhesins, which are believed to facilitate colonization

Methods: In the present study, the prevalence of hmwA, which encodes the HMW adhesin, was determined for a collection of 32 NTHi isolates. Restriction Fragment Length Polymorphism [RFLP] was performed to advance our understanding of hmwA binding sequence diversity

Results: The results demonstrated that hmwA was detected in 61% of NTHi isolates. According to RFLP, isolates were divided into three groups

Conclusion: Based on these observations, it is hypothesized that some strains of nontypeable Haemophilus influenzae infect some specific areas more than other parts

Frequency and molecular characterization of rifampicin-resistance in rpoB region of multiple drug resistance [MDR] isolates from tuberculosis patients in southern endemic region of Iran

The aim of this study was to investigate the frequency, location and type of rpoB gene mutations in Mycobacterium tuberculosis [MTB] collected from patients in the southern endemic region of Iran. Drug susceptibility testing was determined by using the BACTEC system and the center for diseases controls [CDC] standard conventional proportional method. In 29 rifampicin-resistant MTB [85%] isolates, 60 mutations and 13 micro-deletions were identified. Missense mutations produced 23 types of amino acid substitutions. In five rifampicin-resistant MTB isolates [15%] no mutations were found in the core region of the rpoB gene. All silent mutations were localized in codon 507. Most frequent mutations detected in Iranian strains, were found in codons 523 and 526. Five alleles in codon 526 and three alleles occurring in triplets in each of the codons 507, 508, 513 were also found. Thus in Iran the highest frequency of common mutations shared between primary and secondary infections was found to occur in codons 523 and 526