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

Mutations in codon 315 of the katG gene associated with high-level resistance to isoniazid

The aim of this study was to investigate the significance of mutation in codon 315 of katG gene and its correlation with high-level of resistance to isoniazid, nuclotide and amino acid changes in mycobacterium tuberculosis [MTB] isolates randomly collected from sputums of 42 patients with active pulmonary tuberculosis in different regions of Belarus. Drug susceptibility testing was determined using the CDC standard conventional proportional method. DNA Extraction, katG gene amplification, and DNA sequencing analysis were performed. Six isolates [14%] bearing multi-mutations in three codons [309,315 and 316], 26 Isolates [61.9%] demonstrated multi-mutations in all or two of the above codons, and 8 [19%] were found to have a single mutation in 315. Four types of mutations were identified in codons 315: AGC-ACC [n=36]85%, AGC-AGG [n=1] 2.3%, AGC-AAC [n=2] 4.7%, AGC-GGC [n=1] 2.3%, one type of mutation in 316: GGC-AGC [n=18]41.4%, and four types of mutations in 309: GGT-GGT [n=7]16.1%, GGT-GCT [n=4]9.2%, GGT-GTC [n=3]6.9%, GGT-GGG [n=1]2.7%. In 2 [4.7%] isolates mutations were identified in codons 463, 357, and in codons 454, 357 respectively. MTB in patients from Belarus were found to have high-level resistance to isoniazid in the isolates with mutations in codon 315 [> 10 micro g/mL]