Publications by authors named "Xiu-qin Zhao"
Article Synopsis
- * Researchers analyzed 146 isolates, identifying various mutations and assessing their impact on EMB resistance through minimum inhibitory concentration testing and statistical modeling.
- * Results showed that certain mutations (Met306Val, Met306Ile, Gly406Ala, and Gln497Arg) were significantly related to EMB resistance, with some mutations strongly correlating with high-level resistance, highlighting the complex genetic factors influencing EMB susceptibility.
Article Synopsis
- A new assay called MIRA-LF was developed to quickly and accurately detect fluoroquinolone (FQ) resistance in tuberculosis patients.
- The assay identifies mutations in specific codons of the gyrA gene, which are associated with resistance to levofloxacin (LFX).
- MIRA-LF showed significantly high sensitivity (92.4%), specificity (98.5%), and accuracy (96.5%) compared to traditional testing methods, making it particularly beneficial for use in resource-limited settings.
Article Synopsis
- The study focuses on the emergence and evolution of multidrug-resistant tuberculosis (MDR-TB) in Tibet, revealing that a significant portion of local strains have developed high-level drug resistance.
- Analysis of 576 clinical strains showed that 60.1% had at least one drug-resistance mutation, with 40.1% identified as MDR-TB, indicating a serious public health concern.
- The research underscores the importance of addressing isoniazid resistance, as historical transmission patterns and population growth during the 1970s to 1990s have led to the establishment of large, resistant clusters contributing to the current epidemic in the region.
Article Synopsis
- The study aimed to investigate how specific genetic mutations relate to resistance against the antibiotics rifampin (RIF) and rifabutin (RFB) in bacteria.
- Researchers analyzed 177 clinical isolates, identifying multiple mutations and their impact on the minimum inhibitory concentrations (MICs) for RIF and RFB.
- The findings revealed distinct mutation patterns linked to high-level resistance, underscoring the complexity of rifamycin resistance and its implications for tuberculosis treatment options.*
Article Synopsis
- - The study aimed to explore mutations in the RpoB gene and their role in developing resistance to rifampin (RIF), using structural analysis.
- - Researchers sequenced the RpoB gene in 175 tuberculosis isolates and identified 34 mutations across 17 sites; many of these mutations impact the interaction between RpoB and RIF.
- - Key mutations like S450L and H445D were linked to high-level RIF resistance, offering insights that could inform the creation of new antibiotics and diagnostic methods for tuberculosis.
Simple, rapid, and accurate detection of the Mycobacterium tuberculosis complex (MTBC) and drug resistance is critical for improving patient care and decreasing the spread of tuberculosis. To this end, we have developed a new simple and rapid molecular method, which combines multienzyme isothermal rapid amplification and a lateral flow strip, to detect MTBC and simultaneously detect rifampin (RIF) resistance. Our findings showed that it has sufficient sensitivity and specificity for discriminating 118 MTBC strains from 51 non-tuberculosis mycobacteria strains and 11 of the most common respiratory tract bacteria.
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- The study aimed to assess the immunogenicity of proteins and identify cross-reactive proteins related to two different pathogens.
- Mice were immunized with protein extracts, showing significant immune responses, including increased cytokine and immunoglobulin levels, and better control of bacterial loads.
- Genome analysis identified 396 common genes and 60 cross-reactive antigens between the pathogens, suggesting potential targets for developing new tuberculosis vaccines.
With the increasing incidence of drug-resistant tuberculosis (DR-TB), determining a rapid and accurate drug susceptibility testing (DST) method to identify ethambutol (EMB) resistance in has become essential for patient management in China. Herein, we evaluated the correlation between three phenotypic DST methods, namely, proportion method (PM), MGIT 960 system, and microplate alamar Blue assay (MABA), and DNA sequencing of in 118 isolates from China. When the results of the phenotypic DST methods were compared with those of DNA sequencing, the overall agreement and kappa values of the PM, MGIT 960 system, and MABA were 81.
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- Drug resistant tuberculosis is a major global health issue, and a new reverse dot blot hybridization (RDBH) assay was developed to detect resistance to four key anti-tuberculosis drugs in M. tuberculosis isolates from China.
- The study involved testing 320 clinical samples using the RDBH assay and comparing its accuracy against traditional drug susceptibility testing and sequencing methods.
- Results showed high concordance rates (up to 99%) and sensitivity (up to 97.9%) for the RDBH assay, indicating its potential as a fast, reliable method for identifying drug resistance in tuberculosis.
Article Synopsis
- - The study examined drug-resistant tuberculosis (TB) in 189 patients at a Chinese TB hospital, focusing on the prevalence, risks, and genetic factors associated with the disease.
- - Results showed that 28.6% of the isolates were resistant to at least one anti-TB drug, with 9.5% classified as multidrug-resistant and 1.1% as extensively drug-resistant, particularly affecting rural and previously treated patients.
- - Genetic analysis revealed that 58.7% of the isolates were Beijing genotype strains, with specific mutations identified, but no clear link between genotype and drug resistance was found.
Beijing genotype of Mycobacterium tuberculosis is less associated with drug resistance in south China.
Int J Antimicrob Agents
December 2019
Article Synopsis
- * Results showed that 34.8% of the isolates were resistant to at least one of seven tested drugs, with multidrug-resistant and extensively drug-resistant tuberculosis rates at 17.0% and 1.4%, respectively.
- * Although drug resistance was more common in Beijing genotype strains, the study found no significant difference in drug resistance between the Beijing and non-Beijing genotypes, particularly among previously treated patients.
A retrospective analysis was performed in two major HIV/AIDS referral hospitals in Beijing to evaluate the prevalence of Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacterial (NTM) infections in HIV-infected patients. A total of 627 patients' data were reviewed, and 102 (16.3%) patients were diagnosed with culture-confirmed mycobacterial infection, including 84 with MTB, 16 with NTM, and 2 with both MTB and NTM.
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- The study focuses on the EmbCAB proteins and their link to ethambutol (EMB) resistance in Mycobacterium tuberculosis from China, noting that mutations in these proteins contribute to resistance.
- Researchers sequenced 125 isolates and tested their sensitivity to EMB by assessing growth across 10 concentrations, discovering that 82.6% of EMB-resistant strains had at least one mutation in the studied region.
- The findings indicate that specific and multiple mutations significantly influence EMB resistance levels, with a notable association between high-level resistance and the presence of multiple mutations.
Article Synopsis
- Rapid detection of second-line drug resistance in multi-drug tuberculosis (MDR-TB) is crucial for timely treatment initiation.
- This study utilized multiplex allele-specific PCR (MAS-PCR) to identify specific mutations linked to resistance against the drugs ofloxacin (OFX) and kanamycin (KAN) in 139 MDR-TB isolates from China.
- MAS-PCR showed sensitivities of 67.3% for OFX and 76.5% for KAN, with 100% specificity, indicating it as a reliable method for quick identification of drug resistance in MDR-TB patients.
Article Synopsis
- The Mycobacterium tuberculosis Beijing genotype, originating in China, has rapidly increased in population and spread globally over the past century.
- A study analyzed M. tuberculosis samples throughout China using advanced genotyping techniques to compare molecular profiles and patient data, revealing significant genetic divergence mainly influenced by large-scale distances.
- Findings suggest that while modern isolates show a higher prevalence in children, they do not correlate with increased drug resistance, indicating that factors like virulence may contribute to the widespread dissemination of the recent sublineage of this genotype.
Article Synopsis
- China has a high burden of tuberculosis (TB), with Sichuan province having the second-highest number of cases, particularly in Zigong.
- A study in 2010 analyzed 265 TB samples to understand the genetic makeup and drug resistance of Mycobacterium tuberculosis, using methods like Spoligotyping and MIRU-VNTR typing.
- The findings revealed that the Beijing family strain was the most common, accounting for over half of the cases, and 27.17% of isolates showed resistance to at least one anti-TB drug, with no significant difference in resistance between Beijing and non-Beijing strains.
Article Synopsis
- Genotyping and DNA sequencing of 235 M. tuberculosis isolates from China revealed specific mutations in the lysX gene that serve as markers for Beijing and modern Beijing strains.
- These findings were supported by analysis of 24 additional M. tuberculosis genomes from various countries.
- A new, efficient multiplex allele-specific PCR method was developed to quickly detect these mutations in lysX, successfully identifying all Beijing and modern Beijing strains in the tested samples.
To understand the physiological and molecular mechanisms underlying seedling salt tolerance in rice (Oryza sativa L.), the phenotypic, metabolic, and transcriptome responses of two related rice genotypes, IR64 and PL177, with contrasting salt tolerance were characterized under salt stress and salt+abscisic acid (ABA) conditions. PL177 showed significantly less salt damage, lower Na(+)/K(+) ratios in shoots, and Na(+) translocation from roots to shoots, attributed largely to better salt exclusion from its roots and salt compartmentation of its shoots.
View Article and Find Full Text PDFTo identify the mutations in multi- and extensively drug-resistant tuberculosis isolates and to evaluate the use of molecular markers of resistance, we analyzed 257 multi- and extensively drug-resistant isolates and 64 pan-sensitive isolates from 23 provinces in China. Seven loci associated with drug resistance, including rpoB for rifampin (RIF), katG, inhA and oxyR-ahpC for isoniazid (INH), gyrA and gyrB for ofloxacin (OFX), and rrs for kanmycin (KAN), were examined by DNA sequencing. Compared with the phenotypic data, the sensitivity and specificity for DNA sequencing were 91.
View Article and Find Full Text PDFIdentification of mutations conferring streptomycin resistance in multidrug-resistant tuberculosis of China.
Diagn Microbiol Infect Dis
October 2015
Article Synopsis
- - We studied mutations in 140 multidrug-resistant tuberculosis (MDR-TB) strains from China, focusing on three genes: rpsL, rrs, and gidB, and found that 65.7% were resistant to streptomycin (STR), mainly from the Beijing strain.
- - The study showed a strong correlation between STR resistance and the Beijing family of tuberculosis (P=0.00) and highlighted that specific mutations in rpsL and rrs were common in STR-resistant isolates.
- - Detecting mutations in these genes had high effectiveness, with 94.6% sensitivity and 91.7% specificity, making them reliable indicators for STR resistance, which could aid the development of rapid
Source leaf/sink capacity (SS) traits are important determinants of grain yield (GY) of rice. To understand the genetic basis of the SS relationship in rice, five SS and GY traits of rice were genetically dissected using two reciprocal introgression populations. Seventy-three QTL affecting the SS and GY traits were identified, most of which were detected in one of the parental genetic backgrounds (GBs).
View Article and Find Full Text PDFPrevalence of drug resistant Mycobacterium tuberculosis among children in China.
Tuberculosis (Edinb)
May 2015
The available data on the epidemic of drug resistant tuberculosis (TB) among children in China is limited. This study attempted to clarify the drug resistance profiles of clinical strains isolated from children and estimate risk factors related to acquisition of drug resistance. All Mycobacterium tuberculosis strains from children (age <15 years) and adolescent (age 15-18 years) TB patients received in the strain library of Chinese Center for Disease Control and Prevention between January 2005 and December 2012 were included in the study.
View Article and Find Full Text PDF70 clinical Mycobacterium tuberculosis strains isolated from AIDS patients in two HIV/AIDS referral hospitals in Beijing were used in this study. M. tuberculosis and non-tuberculosis mycobacterium (NTM) were identified by using multi-locus PCR.
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- * A study of 139 MDR-TB isolates in China revealed that 56.8% were resistant to EMB, with a significant portion (82.2%) belonging to the Beijing family, and that 79.1% of isolates had mutations in the embCAB operon.
- * The most frequent mutations were found in the embB gene, especially at codon 306, which closely correlated with EMB resistance; however, using embB306-497 DNA sequencing for detection was highly sensitive but only moderately