Altitudinal Distribution of Ammonia-Oxidizing Archaea and Bacteria in Alpine Grassland Soils Along the South-Facing Slope of Nyqentangula Mountains, Central Tibetan Plateau

<div><p>Nitrogen is a major limiting nutrient for the net primary production of terrestrial ecosystems, especially on sentinel alpine ecosystem. Ammonia oxidation is the first and rate-limiting step on nitrification process and is thus crucial to nitrogen cycle. To decipher climatic influence on ammonia oxidizers, their communities were characterized by qPCR and clone sequencing by targeting <i>amoA</i> genes (encoding the alpha subunit of ammonia mono-oxygenase) in soils from 7 sites over an 800 m elevation transect (4400–5200 m a.s.l.), based on “space-to-time substitution” strategy, on a steppe-meadow ecosystem located on the central Tibetan Plateau (TP). Archaeal <i>amoA</i> abundance outnumbered bacterial <i>amoA</i> abundance at lower altitude (<4800 m a.s.l.), but bacterial <i>amoA</i> abundance was greater in surface soils at higher altitude (≥4800 m a.s.l.). Archaeal <i>amoA</i> abundance decreased with altitude in surface soil, while its abundance stayed relatively stable and was mostly greater than bacterial <i>amoA</i> abundance in subsurface soils. Conversely, bacterial <i>amoA</i> abundance gradually increased with altitude at all three soil depths. Statistical analysis indicated that altitude-dependent factors, in particular pH and precipitation, had a profound effect on the abundance and community of ammonia-oxidizing bacteria, but only on the community composition of ammonia-oxidizing archaea along the altitudinal gradient. These findings imply that the shifts in the relative abundance and/or community structure of ammonia-oxidizing bacteria and archaea may result from the precipitation variation along the altitudinal gradient. Thus, we speculate that altitude-related factors (mainly precipitation variation combing changed pH), would play a vital role in affecting nitrification process on this alpine grassland ecosystem located at semi-arid area on TP.</p></div

The Burden of MDR/XDR Tuberculosis in Coastal Plains Population of China

<div><p>Background</p><p>We conducted a first baseline survey in Jilin Province of China to determine the proportion of drug-resistant tuberculosis (TB), and to analyze risk factors associated with the emergence of drug-resistance.</p><p>Methodology/Principal Findings</p><p>Thirty counties in Jilin Province were randomly selected as survey sites using a stratified cluster sampling method. People enrolled in the survey were new and re-treated, smear-positive pulmonary TB patients newly enrolled in local TB control and prevention institutions during the survey period. Sputum samples were collected, and the susceptibility of bacterial strains to anti-TB drugs was analyzed by proportion method. Based on the survey results, we estimated the number of drug-resistant TB patients and analyzed the risk factors associated with the emergence of drug resistance. Of 1,174 new TB patients and 597 re-treated TB patients, 8.6% and 23.2% were multi-drug resistant (MDR)-TB patients, respectively. Approximately 12% of MDR-TB patients were extensively drug-resistant. We estimate that approximately 1,290 new MDR-TB cases develop in Jilin Province every year. Of these, 810 cases would be new patients, and 480 cases would involve re-treated patients. Risk factors associated with MDR-TB include employment status, educational background, and income level.</p><p>Conclusions/Significance</p><p>Jilin Province remains one of the highest-burden areas in China for drug-resistant TB. The higher number of MDR-TB among new cases suggested that the transmission of drug-resistant strains in Jilin is an urgent problem in the MDR-TB control and prevention system of Jilin Province. Improving the treatment compliance of TB patients and the quality of medical care in public health institutions is urgently needed.</p></div

Resistance to first- and second-line antituberculosis drugs.

<p>Resistance to first- and second-line antituberculosis drugs.</p

Proportion of drug resistance in re-treated tuberculosis cases tested in 11 Chinese provinces.

<p>Proportion of drug resistance in re-treated tuberculosis cases tested in 11 Chinese provinces.</p

Proportion of previously treated tuberculosis patients who completed their last treatment course and the location of last treatment.

<p>Proportion of previously treated tuberculosis patients who completed their last treatment course and the location of last treatment.</p

Reasons for treatment interruption among previously treated tuberculosis patients reported by the patients themselves.

<p>The clinical remission is patient rather than clincican defined.</p

Possible risk factors for the smear results at the end of intensive phase and anti- tuberculosis outcomes at the end of consolidation phase, respectively.

<p>IQR, inter-quartile range.</p>*<p>For the data of 51 patients missed, 4253 patients’ data were analyzed.</p>#<p>For the data of 16 patients missed, 4288 patients’ data were analyzed. Successful outcomes defined as the completion of treatment and patients being cured. Unsuccessful outcomes defined as treatment failure, default and death because of ADRs due to DOTS therapy.</p

Incidence, onset time and seriousness of adverse drug reactions due to directly observed treatment strategy therapy in 4304 Chinese tuberculosis patients.

<p>IQR, inter-quartile range.</p>#<p>The incidence of ADR was standardized for age and gender with direct standardization using one reference population that from national TB epidemic surveillance database of 2008.</p>†<p>It was from initiation of treatment.</p>§<p>Serious ADRs were defined as any untoward medical occurrence that at any dose results in death, requires hospital admission or prolongation of existing hospital stay, results in persistent or significant disability/incapacity, or is life threatening.</p>$<p>It was the time that ADRs were found, not the exact time it happened.</p>‡<p>Nervous system disorders included auditory nerve damage, optic nerve damage, peripheral nervous damage and central nervous system damage.</p>€<p>Others included one with interstitial pneumonia and another with hypokalemia.</p>*<p>For 82 patients got two ADRs, sixteen got three and one got four, 766 cases were detected and the denominator was 4304+82+32+3 = 4421.</p

Baseline Characteristics of 4304 Chinese tuberculosis patients.

<p>IQR, inter-quartile range.</p

Impact of ADRs due to directly observed treatment strategy therapy on smear results at the end of intensive phase and anti-TB treatment outcomes.

<p>ADRs, adverse drug reactions; TB, tuberculosis; OR, odds ratio; CI, confidence internal; AR%, attributable risk proportion; PAR%, population attributable risk proportion.</p><p>& A total of 518 patients developed ADRs within the intensive phase. For the data of 51 patients missed, 4253 patients’ data were analyzed.</p>$<p>A total of 649 patients developed ADRs at the end of anti-TB treatment. For the data of 16 patients missing, 4288 patients’ data was analyzed. Successful outcomes defined as the completion of treatment and patients being cured. Unsuccessful outcomes defined as treatment failure, default and death because of ADRs due to DOTS therapy.</p>*<p>Age, gender, TB treatment history and disease history were adjusted using logistic regression analysis.</p>§<p>Age, gender, TB treatment history and HBsAg status were adjusted using logistic regression analysis.</p>#<p>AR% and PAR% were calculated based on adjusted OR, respectively.</p