ABSTRACT
Background: Severe acute respiratory syndrome coronavirus 2 was first reported in December 2019 and it has spread globally ever since. The HLA system is crucial in directing anti-viral immunity and recent studies are investigating the possible involvement of the HLA genes on the severity of immune inflammation in different phases of COVID-19. Methods: In this cross-sectional study, peripheral blood-extracted genomic DNAs of 109 COVID-19 patients and 70 healthy controls were genotyped for different alleles of HLA-A, HLA-B, and HLA-DRB1 loci using sequence-specific primer PCR method. Results: The results indicated that frequencies of HLA-DRB1*11:01 and HLA-DRB1*04:03 were significantly higher in severe patients rather than moderates (p: <0.001 and 0.004, respectively). Also, it was observed that HLA-DRB1*04:01 was more frequent in moderate patients and healthy controls (p:0.002). In addition, HLA-B*07:35, and HLA-DRB1*07:01 showed higher frequencies in patients compared with controls (p: 0.031 and 0.003 respectively). Inversely, due to the higher frequencies of HLA-B*51:01 (p:0.027), HLA-DRB1*11:05 (p:0.003), HLA-DRB1*13:05 (p:0.022), and HLA-DRB1*14:01 (p:0.006) in healthy individuals rather than patients, they may be associated with COVID-19 resistance. Conclusion: The results show that, based on the population differences, the type of alleles related to the severity of COVID-19 is different, which should be clarified by designing large-scale studies in order to develop HLA-based treatments and vaccines.
ABSTRACT
Tuberculosis (TB) is one of the leading causes of mortality among infectious diseases and accounts for a serious health hazard wordwide. Apart from TB, the members of non-tuberculous mycobacteria (NTM), which includes around 170 species, may also cause different diseases in humans. Therefore this study aimed to investigate the distribution of NTM strains isolated from extrapulmonary (EP) samples by Real-Time PCR and PCR-sequencing methods in Southwest Iran. Three hundred and twenty-five suspected EP samples were collected from patients referred to the referral hospitals in Ahvaz, Iran. The isolates were initially screened by acid fast staining and identified by phenotypic culture and biochemical tests. The Real-Time PCR and rpoB- based PCR methods were performed followed by sequence analysis of rpoB gene. From 124 samples, 77 (62%) were positive for NTM by culture and rpoB sequence analysis. M. fortuitum was the most commonly isolated NTM in present study. In Real-Time PCR, only 69 (55.64%) isolates showed more homology with standard NTM isolates. In general, the growing trend of EPNTM infections in Iran needs specific programs and resources to get a better diagnosis. PCR sequencing is a reliable method, it can be used for definitive identification of positive cultures for identification of NTM species.
