Jianyong Zhang

High prevalence of multidrug-resistant tuberculosis in Zunyi, Guizhou Province of China

Sir, According to the WHO Report 2010, China had the most multidrug-resistant tuberculosis (MDR-TB) cases in 2008, followed by India and Russia, and was ranked 16th in terms of the estimated proportion of primary (5.7%) and acquired (previously treated) MDR-TB cases among the 27 MDR-TB highburden countries. However, our recent drug-susceptibility surveillance results indicated that the prevalence of acquired MDR-TB cases in the Zunyi area, Guizhou province, China, was much higher (45.1%) than the average prevalence of acquired MDR-TB in China (25.6%), but lower than those in the top six MDR-TB high-burden countries (Tajikistan, Kazakhstan, Azerbaijan, Republic of Moldova, Uzbekistan and Lithuania). To determine the prevalence and trends of drug-resistant TB in the Zunyi area, in order to improve the treatment outcomes of TB patients, 263 Mycobacterium tuberculosis clinical isolates were collected at the Affiliated Hospital of Zunyi Medical College from 2008 to 2010 and used in drug susceptibility testing against rifampicin, isoniazid, streptomycin and ethambutol. We used the proportion method on Lowenstein–Jensen media with different concentrations of drugs (rifampicin 40 mg/L, isoniazid 0.2 mg/L, streptomycin 4 mg/L and ethambutol 2 mg/L). The standard M. tuberculosis H37Rv strain was used as a control for all testing. To compare our results with those from other provinces of China, we selected recent survey results from Shanghai and 4 out of the 10 provinces (covering 38% of the total Chinese population) with the highest rates of MDR among new TB cases (5.4%–10.4%), and combined them with ours in Table 1. Results indicated that the Zunyi area had the highest prevalence of MDR-TB among previously treated (45.1%) and the second highest among new (8.1%) TB cases in China. In addition, it was observed that the proportions of rifampicin and isoniazid resistance in previously treated (56.0% versus 59.3%) and new (12.2% versus 14.5%) TB cases from the Zunyi area were similar (Table 1), which indicated that isoniazid resistance might be related to rifampicin resistance and that screening for rifampicin resistance could be used as a marker for the detection of MDR-TB. Since isoniazid has not been widely used as monotherapy for latent TB in China, this could explain the relative lack of single resistance to isoniazid in new TB cases observed in this study. It is obvious that percentages of TB cases with resistance to any of the four drugs in the Zunyi area were much higher than those from other provinces among previously treated TB cases (Table 1), suggesting that the Zunyi area of Guizhou province is one of the worst-affected areas in China and should be included in future surveillance of drug resistance in tuberculosis to better represent the prevalence of MDR-TB in China. To compare our results with those from other high-burden countries, such as India and Russia, we selectively included in Table 1 four studies with the highest proportions of MDR among previously treated patients (from 49% in Haryana to 38.2% in Rajasthan) out of the eight studies from India, five countries with the highest proportions of MDR among new TB cases (from 14.4% in Latvia to 4.0% in Ivanovo Oblast) from 35 countries that participated in the global surveillance (1994–97), and five countries with the highest proportions of MDR among new TB cases (from 22.3% in Azerbaijan to 14.8% in Uzbekistan) out of 83 countries/territories surveyed between 2002 and 2007. Comparison of the results shows that the Zunyi area of Guizhou Province, China, has the highest rate of TB cases resistant to ethambutol among previously treated patients (41.8%), and is one of the top 10 areas in the world in terms of the estimated proportion of MDR-TB cases among previously treated TB cases. Consequently, more surveillance should be conducted in the Zunyi area to monitor the trend of MDR-TB transmission, improve the treatment outcomes of TB patients and control the spread of drug-resistant TB, especially MDR-TB.

Genetic Diversity and Drug Susceptibility of Mycobacterium tuberculosis Isolates from Zunyi, One of the Highest-Incidence-Rate Areas in China

ABSTRACT Mycobacterium tuberculosis isolates from Zunyi were found more diversified but clustered less frequently to the Beijing family compared to isolates from other areas of China. These observations, on top of the fact that the Zunyi area has a high prevalence of multidrug-resistant tuberculosis (MDR-TB), support the notion that Beijing family isolates may not be linked to MDR-TB.

Qualitative and quantitative analyses of influenza virus receptors in trachea and lung tissues of humans, mice, chickens and ducks

To accurately determine the expression and distribution patterns of two influenza virus receptors (SAα2,3-gal and SAα2,6-gal) in trachea and lung tissues of humans, mice, chickens and ducks, we analyzed lectin immunofluorescence stainings of various tissue sections qualitatively and quantitatively. Results from the qualitative analysis showed that both influenza virus receptors were expressed in lung tissues of humans, mice, chickens and ducks as well as trachea tissues of mice and ducks. However, SAα2,6-gal receptor was expressed only in the human trachea tissue and SAα2,3-gal receptor was expressed only in the chicken trachea tissue. Results from the quantitative analysis demonstrated that both receptors were expressed in trachea tissues of human and mouse, as well as in lung tissues of humans, chickens and ducks. Meanwhile, our results also showed that the expression and distribution of influenza virus receptors in the same tissue were not always uniform, indicating that their distribution and expression in various tissues are not simply the distinction between the presence or absence of receptors, but rather the difference in the amount of expressed receptors.

Cycloserine-Induced Fever in a Patient with Multidrug-Resistant Tuberculosis and its Successful Desensitization: A Case Report

Cycloserine is one of the second-line anti-tuberculosis drugs used for treating multidrug-resistant tuberculosis (MDR-TB). Psychiatric and neurologic adverse reactions of cycloserine are commonly observed; however, fever as its only adverse reaction was rare. Here we report a case of cycloserine-induced fever in a 23-year-old female patient with MDR-TB and its successful management. After desensitization, the patient was able to continue the treatment regimen for MDR-TB and her symptoms were improved significantly. Our case indicates that fever could be the only adverse reaction of cycloserine in a patient who uses cycloserine as part of a treatment regimen for MDR-TB and the fever is manageable.

Whole-Genome Sequences of Two Clinical Isolates of Extensively Drug-Resistant Mycobacterium tuberculosis from Zunyi, China

ABSTRACT Before 2013, 92 countries reported extensively drug-resistant Mycobacterium tuberculosis cases to the WHO. Here, we announce the genome sequences of two clinical isolates of extensively drug-resistant tuberculosis (XDR-TB) from Zunyi, China. The genome sequences are composed of 4,411,507 bp and 4,411,515 bp with 2,210 and 2,071 variants, respectively, when compared to the H37Rv genome.

Qualitative and quantitative analyses of influenza virus receptors in trachea and lung tissues of human, mouse, chicken and duck

To determine precisely the expression and distribution patterns of two influenza virus receptors(SAα2,3-gal and SAα2,6-gal) in trachea and lung tissues of human,mouse,chicken and duck,we analyzed lectin immunofluorescence stainings of various tissue sections qualitatively and quantitatively.Results from the qualitative analysis showed that both influenza virus receptors were expressed in lung tissues of human,mouse,chicken and duck as well as trachea tissues of mouse and duck;however,SAα2,6-gal receptor was expressed only in the human trachea tissue and SAα2,3-gal receptor was expressed only in the chicken trachea tissue.Results from the quantitative analysis demonstrated that both receptors were expressed in trachea tissues of human and mouse,as well as in lung tissues of human,chicken and duck.Meanwhile,our results also showed that the expression and distribution of influenza virus receptors in the same tissue were not always uniform,indicating that their distribution and expression in various tissues are not simply the distinction between the presence or absence of receptors,but rather the difference in the amount of expressed receptors.

Survey and Molecular Characterization of Drug- Resistant M. tuberculosis Clinical Isolates from Zunyi, Guizhou Province of China

Tuberculosis (TB) is one of the leading infectious disease killers in the world, especially in developing countries. The increasing frequency of human-to-human transmission of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis poses challenges for effective therapeutic options and infection control. MDR-TB is defined as a form of TB that is resistant to at least isoniazid and rifampin, which are used to treat all TB patients. XDR-TB is a form of TB that is resistant to at least rifampicin and isoniazid in addition to any fluoroquinolone, and at least one of the three injectable secondline anti-TB drugs (amikacin, capreomycin and kanamycin). Based on the WHO Report 2010, China was ranked number one among high burden countries in terms of the estimated number of MDR-TB cases in 2008, and number two in terms of total numbers of TB cases in the world with the incidence rate per capita of 99 per 100,000 populations (WHO, 2011). Guizhou province is one of the highest-incidence-rate areas in China, and its prevalence of drug-resistant TB is higher than most of other provinces of China (Chen et al., 2011). The Affiliated Hospital of Zunyi Medical College is one of the specialized centers in Guizhou certified by the provincial government for the treatment of MDR-TB patients. In 2010, more than 15,000 TB patients were treated at the hospital. In order to determine the molecular characteristics of drug-resistant TB and assist in making informed TB treatment decisions for TB patients in the Zunyi area of Guizhou province, hundreds of M. tuberculosis clinical isolates were collected at the Affiliated Hospital of Zunyi Medical College and used for the systematic surveillance and other studies. We have made some progresses in the detection and molecular characterization of drug-resistant M. tuberculosis clinical isolates using different research methods such as M. tuberculosis culture, spoligotyping, gene sequencing, proteomics and drug susceptibility testing against first-line and second-line antituberculosis drugs.