Genotyping of Pneumocystis jirovecii isolates obtained from clinical samples by multilocus sequencing: a molecular epidemiology study conducted in Turkey.

Pneumocystis jirovecii is an opportunistic respiratory pathogen causing Pneumocystis pneumonia (PcP) in immunocompromised patients. The aim of this study was to investigate the genetic diversity of P. jirovecii isolates (n: 84) obtained from PcP patients using multilocus sequencing method based on mt26S, SOD, and CYB loci. Among the 84 clinical samples that were positive for P. jirovecii DNA, 31 (36.90%) of them were genotyped using at least one locus. Of the 31 clinical samples, 26 of them were successfully genotyped using all loci whereas three samples were genotyped using either mt26S/CYB loci or mt26S/SOD loci. Additionally, there were two more clinical samples that were genotyped using CYB or SOD locus. Using mt26S locus, genotypes 2, 3, 7, and 8 were detected. Frequencies of genotype 7 and 8 were higher and both of them were found in 11 (n: 29; 37.93%) clinical samples. Using SOD locus, SOD 1, 2, and 4 genotypes were detected. SOD 1 was the predominant genotype (20/28; 71.42%). During the analyses of CYB locus, CYB 1, 2, 5, 6, and 7 as well as a new CYB genotype were detected. CYB 1 (16/29; 55.17%) and 2 (10/29; 34.48%) were the predominant genotypes. Overall, according to the multilocus sequencing results E, F, M, N, P, and V multilocus genotypes were detected among the PcP patients. In addition, SOD 1 was the predominant genotype and CYB had a more polymorphic locus.

Evaluation of the performance of QuantiFERON®-TB Gold plus test in active tuberculosis patients.

The aim was to evaluate the sensitivity and the possible factors affecting the sensitivity of the QuantiFERON®-TB Gold Plus (QFT-Plus) assay in culture-positive active TB (Tuberculosis) patients, to investigate the possible causes of negative and indeterminate results in active TB patients, and to compare the QFT-Plus results of active TB patients and latent tuberculosis infection (LTBI) cases. The QFT-Plus assay was performed in 46 active TB patients and 64 LTBI. The sensitivity of the test was found as 79.5% in all culture-positive patients, 72.7% in the immunocompromised patients, and 86.4% in the non-immunocompromised patients. Compared to active TB, individuals with LTBI had a lower T-cell response and lower IFN-É£ concentrations. It was determined that the immunocompromisation reduced the sensitivity of the test and the secreted IFN-É£ concentrations and increased the indeterminate results in patients with active TB. There was no difference in secreted IFN-É£ concentrations between M. tuberculosis clones, but higher IFN-É£ concentrations in patients infected with M. tuberculosis strains compared to patients infected with zoonotic strains. Compared with active TB, response to "only to TB2" was significantly higher in LTBI. In conclusion, it was concluded that TB2 tube increased sensitivity in LTBI but may not contribute to sensitivity in active TB.