English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  Detection of pyrazinamide (PZA) resistance in  Mycobacterium tuberculosis  (TB) patients is critical, especially in dealing with multidrug-resistant  Mycobacterium tuberculosis  (MDR-TB) case. Up to date, PZA drug susceptibility testing (DST) has not been regularly performed in China. The prevalence and molecular characteristics of PZA resistance in  M.tuberculosis  isolates, especially MDR-TB have not been studied in Ningbo, China. This study aimed to analyze the phenotypic and molecular characterization of PZA resistance among MDR-TB isolates in Ningbo.    Methods  A total of 110 MDR-TB isolates were collected from the TB patients who were recorded at local TB dispensaries in Ningbo. All clinical isolates were examined by drug susceptibility testing and genotyping. DNA sequencing was used to detect mutations in the pncA gene associated with PZA resistance.    Results  The prevalence of PZA resistance among MDR-TB strains in Ningbo was 59.1%. With regard to the history and the outcome of treatments among MDR-TB cases, the percentages of re-treated MDR-TB patients in the PZA-resistant group and of successful patients in PZA-susceptible group were significantly higher than the ones in the PZA-susceptible group and in the PZA-resistant group, respectively ( P  = 0.027,  P  = 0.020). The results showed that the resistance of streptomycin (67.7% vs 46.7%,  P  = 0.027), ethambutol (56.9% vs 33.3%,  P  = 0.015), ofloxacin (43.1% vs 11.1%,  P  = 0.000), levofloxacin (43.1% vs 11.1%,  P  = 0.000), pre-XDR (pre-Xtensively Drug Resistance) (38.5% vs 15.6%,  P  = 0.009), were more frequently adverted among PZA-resistant isolates compared with PZA-susceptible isolates. In addition, 110 MDR-TB was composed of 87 (PZA resistant, 78.5%) Beijing strains and 23 (PZA resistant, 21.5%) non-Beijing strains. Fifty-four out of 65 (83.1%) PZA-resistant MDR strains harbored a mutation located in the  pnc A gene and the majority (90.7%) were point mutations. Compared with the phenotypic characterization, DNA sequencing of  pnc A has sensitivity and specificity of 83.1 and 95.6%.    Conclusion  The mutations within  pnc A gene was the primary mechanism of PZA resistance among MDR-TB and DNA sequencing of  pnc A gene could provide a rapid detection evidence in PZA drug resistance of MDR-TB in Ningbo.

Phenotypic and molecular characterization of pyrazinamide resistance among multidrug-resistant Mycobacterium tuberculosis isolates in Ningbo, China