ABSTRACT
@#Abstract: Objective To analyze the accuracy and feasibility of GeneXpert MTB/RIF (GeneXpert) detection in the detection of Mycobacterium tuberculosis and the characteristics of rifampicin-resistant rpoB gene mutations. Methods A total of 4 234 sputum samples from suspected tuberculosis patients diagnosed in Sanya tuberculosis designated hospitals from 2015 to 2021 were selected and subjected to sputum smear, solid culture, drug sensitivity test by solid proportion method and GeneXpert detection. Results The positive detection rates of sputum smear, solid culture and GeneXpert of 4 234 sputum samples were 29.24% (1 238/4 234), 32.17% (1 362/4 234) and 35.40% (1 499/4 234), respectively. The positive detection rate of GeneXpert was higher than that of sputum smear, and the difference was statistically significant (χ2=36.775, P<0.01). It was slightly higher than solid culture, and the difference was not statistically significant (χ2=9.908, P=0.02). Taking solid culture results as the gold standard, the sensitivity and specificity of GeneXpert for detecting MTB were 91.04% (1 240/1 362) and 90.98% (2 613/2 872), respectively. According to the proportional drug susceptibility test results as the gold standard, the sensitivity and specificity of GeneXpert in detecting rifampicin resistance were 96.96% (96/99) and 98.86% (1 128/1 141), respectively, with the consensus rate of 98.71%. The accuracy of rifampicin resistance in GeneXpert group without probe mutation was significantly lower than that in group with probe mutation. There was a statistical difference in probe mutation frequency between newly treated and retreated cases. The analysis of rpoB gene mutation frequency characteristics showed: Probe E (50.00%) > Probe A (22.12%) > Probe D (14.42%) > Probe B (6.73%) > combined probe (5.77%) > Probe C (0.96%). Conclusions GeneXpert detection can quickly and effectively diagnose rifampicin-resistant tuberculosis, which is helpful for early clinical diagnosis and treatment. In this region, the rpoB gene mutation probes of rifampicin-resistant tuberculosis mainly occurr in Probe E and Probe A, with the least mutations in Probe C.
ABSTRACT
The study is aimed to estimate the effect of different heavy metals such as Hg2+, Cd2+, Mn2+, Cr3+, Ni2+, Se2O3(2-), As2O3 water solution and combined effects of Hg2+, Mn2+, Cr3+ on lipid peroxidation in mice liver homogenate in vitro. Lipid peroxidation was determined as thiobarbituric acid-reacting materials (TBA). We select five different concentrations of selected ions for experiments. Correlations used to identify the concentration of ions associated with lipid peroxidation. The rate of lipid peroxide formation in mice liver homogenate increased with the gradual addition of alcohol. When alcohol dose was up to 0.5 ml, the rate of lipid peroxide formation was greatest. At tested concentrations, the effects of metal ions on lipid peroxidation induced by alcohol were classified into three groups, and are as follows: (1) simulative, Hg2+. (2) inhibitory, Mn2+, Cr3+, Ni2+, Se2O3(2-). (3) ambiguous, Cd2+, As2O3 water solution. When Hg2+, Mn2+ and Cr3+ were added to the mice liver homogenate with alcohol at the same time, Hg2+, Mn2+ were the main agents for the rate of alcohol induced lipid peroxidation. The simulative effect of Hg2+ on lipid peroxidation induced by alcohol indicate that alcohol-drinkers will have further health risk when they are exposed in polluted regions than others, and Mn2+, Cr3+, Ni2+, Se2O3(2-) may act as free radical scavengers and preventive remedy for alcoholism in part. Furthermore, analysis of combined effect of Hg2+Mn2+ and Cr3+ provide us a new way to estimate the combined effect of multi-materials.