GeneChip analysis of resistant Mycobacterium tuberculosis with previously treated tuberculosis in Changchun.

BACKGROUND: With the widespread use of rifampicin and isoniazid, bacterial resistance has become a growing problem. Additionally, the lack of relevant baseline information for the frequency of drug-resistant tuberculosis (TB) gene mutations is a critical issue, and the incidence of this infection in the city of Changchun has not investigated to date. However, compared with the slow traditional methods of drug susceptibility testing, recently developed detection methods, such as rifampicin and isoniazid resistance-related gene chip techniques, allow for rapid, easy detection and simultaneous testing for mutation frequency and drug resistance. METHODS: In this study, the rifampicin and isoniazid resistance-related gene mutation chip method was employed for an epidemiological investigation. To assess the gene mutation characteristics of drug-resistant TB and evaluate the chip method, we tested 2143 clinical specimens from patients from the infectious diseases hospital of Changchun city from January to December 2016. The drug sensitivity test method was used as the reference standard. RESULTS: The following mutation frequencies of sites in the rifampicin resistance gene rpoB were found: Ser531Leu (52.6%), His526Tyr (12.3%), and Leu511Pro (8.8%). The multidrug-resistance (MDR)-TB mutation frequency was 34.7% for rpoB Ser531Leu and katG Ser315Thr, 26.4% for rpoB Ser531Leu and inhA promoter - 15 (C → T), and 10.7% for rpoB His526Tyr and katG Ser315Thr. In addition, drug susceptibility testing served as a reference standard. In previously treated clinical cases, the sensitivity and specificity of GeneChip were 83.1 and 98.7% for rifampicin resistance, 79.9 and 99.6% for isoniazid resistance, and 74.1 and 99.8% for MDR-TB. CONCLUSIONS: Our experimental results show that the chip method is accurate and reliable; it can be used to detect the type of drug-resistant gene mutation in clinical specimens. Moreover, this study can be used as a reference for future research on TB resistance baselines.

First Report of Toxoplasma gondii Infection in Tuberculosis Patients in China.

In recent years, coinfection of tuberculosis (TB) and parasitosis in humans is an emerging problem in coendemic areas, which has been increasingly highlighted in developing countries. However, there is limited information about the prevalence of Toxoplasma gondii infection in TB patients. Therefore, through a case-control study, 924 TB patients hospitalized for diacrisis or treatment in northeastern and eastern China, and 924 control subjects from the general population of the same region matched with gender, age, and residence were examined for the presence of IgG and IgM antibodies to T. gondii and associated sociodemographic and behavioral characteristics in a population of TB patients. Seroprevalence of IgG antibodies to T. gondii in TB patients (122/924, 13.2%) was significantly higher than control subjects (90/924, 9.7%) (p = 0.019), and 26 (2.8%) TB patients and 19 (2.1%) controls were positive for anti-T. gondii IgM antibodies (p = 0.291), respectively. Multivariate analysis showed that T. gondii infection was associated with keeping cats at home, presence of stray cats, and consumption of raw/undercooked meat. The present study first revealed the seroprevalence of T. gondii infection in TB patients in China. Moreover, parasitological surveys should be regularly carried out among TB patients, aiming to prevent the possibility of severe toxoplasmosis.

[The impact of HBeAg positivity/negativity and HBV DNA loads on the prognosis of chronic severe hepatitis B].

OBJECTIVE: To explore the impact of HBeAg positivity/negativity and HBV DNA loads on the prognosis of chronic severe hepatitis B. METHODS: 206 patients with chronic severe hepatitis B hospitalized in Beijing Ditan Hospital from July 2002 to Dec. 2004 were analyzed. HBeAg positivity/negativity, HBV DNA loads and other factors relating to the prognosis of the patients were studied with univariate and multivariate analyses. RESULTS: Chi2 univariate analysis showed that there was no significant difference in the prognosis between different HBeAg groups (chi2 = 0.440, OR = 0.777, 95% CI 0.424-1.425, P = 0.50). But there was a significant difference in the prognosis between different HBV DNA load groups: the prognosis of patients with lower HBV DNA loads was better than those with higher loads (chi2 = 9.806, OR = 3.055, 95% CI 1.554-6.007, P = 0.002), and the improving rates of the two groups were 53.1% and 27.0% respectively. Using multivariate logistic regression analysis, 9 screened factors showed great impact on the prognosis of chronic severe hepatitis B. Cirrhosis, hepatorenal syndrome, hepatic encephalopathy, PTA < 20%, TBil > 513 mmol/L, Alb < 30 g/L, CHO < 1.6 mmol/L, PLT < 5 x 10(9)/L, and higher HBV DNA loads (HBV DNA > 3 x 10(4) copies/ml in HBeAg negative patients and > 1 x 10(5) copies/ml in HBeAg positive patients) were shown to be associated with a poor prognosis. Coefficients of regression of the above factors were 1.539, 21.356, 1.398, 1.650, 2.440, 2.266, 1.738, 2.631 and 2.656 respectively. The coefficients of regression of HBV DNA loads were: B = 2.656, Wald = 7.768, P = 0.005, EXP(B) = 14.235, and 95.0% CI for EXP(B) = 2.199-92.133. CONCLUSIONS: Our results indicate that the HBV DNA loads were one of the most important factors influencing the prognosis of the chronic severe hepatitis B patients, the importance is only next to hepatorenal syndrome and over grade II hepatic encephalopathy. HBeAg positivity/negativity has no influence on the prognosis, but HBV DNA loads are important; the lower the viral loads, the better the prognosis.

[Effects of cucumber leaf's PS II activity and electron transfer on its PS I activity in recovery process after chilling-induced photoinhibition].

Taking Cucumis sativus L. (Jinchun No. 4) as test material, through the determination of chlorophyll-a fluorescence transient and light absorbance at 820 nm, and in combining with chlorophyll quenching, this paper studied the recovery of cucumber leaf' s PS I and PS I activities and the interactions between PS I and PS II in the recovery process at room temperature (25 degrees C) and under different light intensities (0, 15, and 200 micromol x m(-2) x s(-1)) after six hours of low temperature (4 degrees C) and strong light (200 micromol x m(-2) x s(-1)) stress. Different extent of photoinhibition of the PS II and PS I occurred after the stress. During the recovery process at room temperature, the PS II activity recovered quickly and was insensitive to light intensity, while the PS I activity recovered quickly under weak light intensity (15 micromol x m(-2) x s(-1)) but slowly under strong light intensity (200 micromol x m(-2) x s(-1)), suggesting that after the chilling-induced photoinhibition, the reduced electron transfer from PS II to PS I protected the PS I from further inhibition, accelerating the recovery of PS I activity. In the breeding of chilling-resistant species of cucumber, it should not only pursue the higher chilling-resistance of PS II and faster recovery of PS II after chilling-induced photoinhibition, but also pay more attention to the coordinating of PS I and PS II during and after the chilling-induced photoinhibition. In the culture of cucumber, after chilling happened, a practical method to reduce light intensity would help the recovery of cucumber leaf PS I activity to protect the photosynthetic apparatus against photoinhibition.