The aim of this study was to investigate the significance of multiple mutations in the rpoB gene as well as predominant nucleotide changes and their correlation with high levels of resistance to rifampin (rifampicin) in Mycobacterium tuberculosis isolates that were randomly collected from the sputa of 46 patients with primary and secondary cases of active pulmonary tuberculosis from the southern region (Afghanistan border) of Iran where tuberculosis is endemic. Drug susceptibility testing was performed using the CDC standard conventional proportional method. DNA extraction, rpoB gene amplification, and DNA sequencing analysis were performed. Thirty-five (76.09%) isolates were found to have multiple mutations (two to four) in the rpoB (␤-subunit) gene. Furthermore, we demonstrate that the combination of mutations with more prevalent nucleotide changes were observed in codons 523, 526, and 531, indicating higher frequencies of mutations among patients with secondary infection. In this study, 76.08% (n ‫؍‬ 35) of all isolates found to have mutation combinations involving nucleotide changes in codons 523 (GGG3GCG), 531 (TCG3TTG or TTC), and 526 (CAC3CGC,

ObjectivesThis study aimed to evaluate the specificity, sensitivity, cost, and turn-around time of three methods of gene polymorphism analysis and to study the relationship between IL28B rs12979860 and SVR rate to pegIFN-α/RVB therapy among patients with chronic hepatitis C.MethodsA total of 100 samples from chronic hepatitis C patients were analyzed in parallel using the three methods: direct sequencing, real-time polymerase chain reaction (PCR), amplification refractory mutation system (ARMS)-PCR.ResultsThe different profiles for IL28B rs12979860 alleles (CC, CT, and TT) obtained with PCR-RFLP, ARMS-PCR, and direct sequencing were consistent among the three methods. Prevalence of rs12979860 genotypes CC, CT and TT in HCV genotype 1a was 10(19.6%), 35(68.6%), and six (11.8%), respectively, and in HCV genotype 31, it was 13(26.5%), 31(63.3%), and five (10.2%), respectively. No significant difference was seen between rs12979860 genotype and HCV genotype (p = 0.710).ConclusionScreening by ARMS – PCR SNOP detection represents the most efficient and reliable method to determine HCV polymorphisms in routine clinical practice.

No abstract

, acid fast bacilli from the family of , is the causative agent of most cases of tuberculosis. Tuberculosis, as a communicable disease, remains a serious public health threat, killing more than one million people globally every year. Primary diagnosis of tuberculosis bacilli (TB) relies mainly on microscopic detection of acid fast bacilli (AFB), but the method suffers from low sensitivity and the results largely depend on the technician's skill. New diagnostic tools are necessary to be introduced for rapid and accurate detection of the bacilli in sputum samples. We, in collaboration with Anda Biologicals, have developed a new platform, named as "Patho-tb", for rapid detection of AFB with high sensitivity and with low dependence on human skills. Evaluation of Patho-tb test performance was done in two settings: (1) primary field study conducted using 38 sputa from high TB prevalence area of Iran (Zabol city near to the Afghanistan border), and (2) main study conducted using 476 sputa from Tehran, capital of Iran. Patho-tb was applied for processed sputum samples in parallel with routine diagnostic methods (including AFB microscopy, culture and PCR). All test results were compared to final clinical diagnostic state of an individual and diagnostic sensitivity (DSe), specificity, positive predictive value, negative predictive value and accuracy of each test results were calculated using standard formulations. Analytical sensitivity and specificity of the Patho-tb test were also determined. Calculated values for five above mentioned parameters are as follows: for field study: AFB (DSe: 29.6, DSp: 81.8, PPV: 80, NPV: 23.1, AC: 44.7), Patho-tb (DSe: 63, DSp: 72.7, PPV: 85, NPV: 44.4, AC: 65.8), and for main study: AFB (DSe: 86.1, DSp: 99.4, PPV: 98.5, NPV: 93.9, AC: 95.2), Patho-tb (DSe: 97.4, DSp: 92.9, PPV: 86.5, NPV: 98.7, AC: 94.3). Reproducibility of Patho-tb test results were near to 100% (Cohen's kappa value between 0.85 and 1). The detection limit of Patho-tb test with 100% positivity rate was 3 × 10 cells/ml of sputum. In the field study, Patho-tb test was 33.4% more sensitive than AFB microscopy, while the improvement was only 11.3% during the main study. Patho-tb results are easy to interpret and the test can be merged with other screening tests, like AFB. Totally, Patho-tb test alone or in conjunction with AFB microscopy is a useful screening tool for TB detection especially in poor geographical lab conditions.

No abstract