Objectives: Tuberculosis (TB) is the leading cause of death from infectious diseases in the world, with an estimated 1.6 million deaths from TB in 2017. The objectives of this study were to determine drug resistance profiles of Mycobacterium tuberculosis clinical isolates and to analyze the trends in drug-resistant and multidrug-resistant tuberculosis (MDR-TB) from 2008 to 2015 at a major hospital in Guizhou, a high-TB burden and resource-limited province of China. Patients and methods: A total of 462 clinical isolates were collected from patients with pulmonary TB during the period from January 2013 to December 2015 and used for determining drug resistance profiles against four first-line and six second-line anti-TB drugs, and the results were compared with those of two previous studies. Results: Exactly 4.4% of new and 44.1% of previously treated TB cases were MDR/rifampicinresistant TB (RR-TB), which were higher than the 2017 global average numbers of 3.5% and 18%, respectively. There were many drug-resistant patterns among MDR-TB isolates and most of them were resistant to three or four anti-TB drugs. The trends in drug-resistant and MDR-TB declined at the hospital from 2008 to 2015. Conclusion: Results of this study show that the prevalence of MDR/RR-TB at a major hospital in Guizhou is higher than the global average and confirm the existence of heterogeneity in drug resistance patterns of MDR-TB isolates. Additionally, three practical measures have played an important role in the overall decline of MDR-TB at the hospital from 2008 to 2015.

BackgroundChina is one of the high-burden countries for multidrug-resistant tuberculosis (MDR-TB), and pyrazinamide is one of the anti-TB drugs used for the shorter MDR-TB treatment regimen. The aim of this study was to determine the correlation between pncA gene mutations and resistance to four first-line anti-TB drugs as well as treatment history in clinical isolates of Mycobacterium tuberculosis.Patients and methodsM. tuberculosis clinical isolates were collected from 318 in-patients with smear-positive TB between October 2008 and September 2016 at a major hospital in Zunyi, Guizhou Province of China, and used for drug susceptibility testing against four first-line anti-TB drugs. Genomic DNA extracted from clinical isolates was used for PCR amplification and DNA sequencing of the pncA gene.ResultsAmong 318 clinical isolates, 129 (40.6%), 170 (53.5%), 66 (20.8%) and 109 (34.3%) were resistant to rifampicin, isoniazid, ethambutol and streptomycin respectively. In addition, 124 clinical isolates were MDR-TB and 71.8% of them were previously treated cases. Sequencing results showed that 46.8% of MDR-TB and 2.2% of drug susceptible isolates harbored a pncA mutation, and 52 types of pncA mutations were detected from 64 isolates. The prevalence of pncA mutations in isolates resistant to first-line anti-TB drugs and previously treated TB cases was significantly higher than that in drug-susceptible isolates and new cases of TB.ConclusionHigh prevalence of pncA mutations in clinical isolates of M. tuberculosis from Zunyi, Guizhou Province of China, is correlated with resistance to four first-line anti-TB drugs, MDR-TB and previously treated TB cases.

Extrapulmonary tuberculosis (EPTB) accounted for 14% of 6.4 million cases of TB that were reported to WHO in 2017, and genitourinary TB (GUTB) is the second most common type of EPTB. The most common site of GUTB is the kidneys and testicular TB is relatively rare. The case of one patient with pulmonary and testicular TB caused separately by two different genotypes of Mycobacterium tuberculosis (Mtb) is further rare. Here, we present an unusual case of TB in which pulmonary TB (PTB) and testicular TB were caused by Mtb isolates with two different genotypes in a 91-year-old male patient from Zunyi, Guizhou Province of China. A better understanding of the mechanism by which a small number of tubercle bacilli are spread from the primary site of PTB to more distant parts/organs of the body, and what factors determine the potential EPTB site will provide us with new ways to prevent and control EPTB infections.

BackgroundAs one of the top three high tuberculosis (TB) burden countries, China is a country where the overall TB incidence continues to decline. However, due to its large population and area, the increased TB burden exists in regional areas.MethodsThis retrospective study analyzed local inpatient pulmonary TB cases in the Affiliated Hospital of Zunyi Medical University (AHZMU) from January 2016 to December 2018 in a high TB incidence and economically-less-developed area of China. Four methods, acid-fast bacilli stain, culture, Xpert and LAMP, were used to detect Mycobacterium tuberculosis (M.tb), while proportional method and Xpert were used to identify rifampicin-resistant TB (RR-TB). Case number, treatment history, M.tb confirmed TB and rifampicin resistant proportion were analyzed to investigate the local TB epidemic.ResultsTotal 3,910 local inpatient cases with pulmonary TB were admitted to AHZMU during this study period. The annual numbers of total TB cases increased 26.4% (from 1,173 to 1,483), while new cases increased 29.6% (from 936 to 1,213) and RR-TB cases increased 2.7 times (from 31 to 84). Meanwhile, the percentage of previously treated cases declined from 20.2 to 18.2% and the M.tb confirmed TB proportion increased from 34.7 to 49.7%.ConclusionThe elevated M.tb confirmed TB proportion and the declined percentage of previously treated cases indicated the improved TB diagnosis and treatment of AHZMU. However, the increasing number of total TB cases, new and RR-TB cases showed an upward trend and increased TB burden in a relatively underdeveloped area of China.