Objective China is among the 30 countries with a high burden of tuberculosis(TB)worldwide,and TB remains a public health concern.Kashgar Prefecture in the southern Xinjiang Autonomous Region is considered as one of th...Objective China is among the 30 countries with a high burden of tuberculosis(TB)worldwide,and TB remains a public health concern.Kashgar Prefecture in the southern Xinjiang Autonomous Region is considered as one of the highest TB burden regions in China.However,molecular epidemiological studies of Kashgar are lacking.Methods A population-based retrospective study was conducted using whole-genome sequencing(WGS)to determine the characteristics of drug resistance and the transmission patterns.Results A total of 1,668 isolates collected in 2020 were classified into lineages 2(46.0%),3(27.5%),and 4(26.5%).The drug resistance rates revealed by WGS showed that the top three drugs in terms of the resistance rate were isoniazid(7.4%,124/1,668),streptomycin(6.0%,100/1,668),and rifampicin(3.3%,55/1,668).The rate of rifampicin resistance was 1.8%(23/1,290)in the new cases and 9.4%(32/340)in the previously treated cases.Known resistance mutations were detected more frequently in lineage 2 strains than in lineage 3 or 4 strains,respectively:18.6%vs.8.7 or 9%,P<0.001.The estimated proportion of recent transmissions was 25.9%(432/1,668).Multivariate logistic analyses indicated that sex,age,occupation,lineage,and drug resistance were the risk factors for recent transmission.Despite the low rate of drug resistance,drug-resistant strains had a higher risk of recent transmission than the susceptible strains(adjusted odds ratio,1.414;95%CI,1.023–1.954;P=0.036).Among all patients with drug-resistant tuberculosis(DR-TB),78.4%(171/218)were attributed to the transmission of DR-TB strains.Conclusion Our results suggest that drug-resistant strains are more transmissible than susceptible strains and that transmission is the major driving force of the current DR-TB epidemic in Kashgar.展开更多
Setting: The Uganda National Tuberculosis Reference Laboratory (NTRL) in Kampala. Objective: The proportion of poor quality specimens received for drug susceptibility testing (DST) at the NTRL and factors contributing...Setting: The Uganda National Tuberculosis Reference Laboratory (NTRL) in Kampala. Objective: The proportion of poor quality specimens received for drug susceptibility testing (DST) at the NTRL and factors contributing to poor specimen quality were assessed. Design: A cross-sectional study was conducted of sputum samples received at the NTRL from patients at high risk for multi-drug-resistant tuberculosis (MDR TB) during July-October 2013. Demographic, clinical, and bacte-riological data were abstracted from laboratory records. A poor quality sample failed to meet any one of four criteria: ≥3 milliliter (ml) volume, delivered within 72 hours, triple packaged, and non-salivary appearance. Results: Overall, 365 (64%) of 556 samples were of poor quality;89 (16%) were not triple packaged, 44 (8%) were <3 mls, 164 (30%) were not delivered on time, and 215 (39%) were salivary in appearance. Poor quality specimens were more likely to be collected during the eighth month of TB treatment (OR = 2.5, CI = 1.2 - 5.1), from the East or Northeast zones (OR = 2.2, CI = 1.1 - 4.8), and from patients who previously defaulted from treatment (OR = 1.9, CI = 1.1 - 3.2). Conclusion: The majority of sputum samples had poor quality. Additional efforts are needed to improve quality of samples collected at the end of treatment, from East and Northeast zones, and from patients who had previously defaulted.展开更多
Objective Tuberculosis remains a severe public health issue, and the Beijing family of mycobacterium tuberculosis （M. tuberculosis） is widespread in East Asia, especially in some areas in China, like Beijing and Tia...Objective Tuberculosis remains a severe public health issue, and the Beijing family of mycobacterium tuberculosis （M. tuberculosis） is widespread in East Asia, especially in some areas in China, like Beijing and Tianjin. This study aimed at determining the mutation patterns of drug-resistant Beijing strains of M. tuberculosis isolated from Tianjin, China. Methods A total of 822 M. tuberculosis isolates were screened for drug resistance by an absolute concentration method and the genotype was identified by PCR. 169 drug-resistant isolates of the Beijing family were analyzed for the potential mutations in the rpoB, katG, inhA promoter region and in rpsL, rrs and embB genes, which are associated with resistance to rifampin （RFP）, isoniazid （INH）, streptomycin （SM） and ethambutol （EMB） respectively by PCR and DNA sequencing. Results Fifty-eight out of 63 RFP-resistant isolates were found to carry the mutations within the 81-bp RFP resistance determining region （RRDR） of the rpoB gene and the most frequent mutations occurred at codon 531 （44.4%）, 526 （28.6%）, and 516 （7.9%） respectively. 16 mutation pattems affecting 12 different codons around the RRDR of rpoB were found. Of 116 INH-resistant isolates, 56 （48.3%） had the mutation of katG 315 （AGC→ACC） （Ser→Thr）, 3 （2.6%） carried S315N （AGC→AAC） and 27 （16.0%） had the mutation of inhA-15A→T. 84 out of 122 SM-resistant isolates （68.9%） displayed mutations at the codons 43 or 88 with AAG→AGG （Lys→Arg） of the rpsL gene and 22 （18.0%） with the mutations at positions 513A→C, 516C→T or 905 A→G in the rrs gene. Of 34 EMB-resistant isolates, 6 had mutation with M306V （ATG→GTG）, 3 with M306I （ATG→ATT）, 1 with M306I （ATG→ATA）, 1 with D328Y （GAT→TAT）, 1 with V348L （GTC→CTC）, and 1 with G406S （GGC→AGC） in the embB gene. Conelusion These novel findings extended our understanding of resistance-related mutations in the Beijing strains of M. tuberculosis and may provide a scientific basis for development of new strategies for diagnosis and control of tuberculosis in China and other countries where Beijing strains are prevalent.展开更多
In order to evaluate the performance of a molecular Hain line probe assay （Hain LPA） for rapid detection of rifampicin and isoniazid resistance of Mycobocterium tuberculosis in China, 1612 smear positive patients we...In order to evaluate the performance of a molecular Hain line probe assay （Hain LPA） for rapid detection of rifampicin and isoniazid resistance of Mycobocterium tuberculosis in China, 1612 smear positive patients were consecutively enrolled in this study. Smear positive sputum specimens were collected for Hain LPA and conventional drug susceptibility testing （DST）. The sensitivity and specificity of Hain LPA were analyzed by using conventional DST as golden reference. The sensitivity, specificity, positive predictive value {PPV） and negative predictive value （NPV） for rifampicin resistance detection were 88.33%, 97.66%, 81.54%, and 98.62%, respectively. The sensitivity, specificity, PPV and NPV for isoniazid resistance detection were 80.25%, 98.07%, 87.25%, and 96.78%, respectively. These findings suggested that Hain LPA can be an effective method worthy of broader use in China.展开更多
Objective To compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis （PTB）. Methods Clinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and...Objective To compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis （PTB）. Methods Clinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and Xi＇an Chest Hospital from January to December in 2014. The sputum samples of smear negative PTB suspects were collected and decontaminated. The sediment was used to conduct MTBDRplus V2, Xpert MTB/RIF and drug susceptibility test （DST）. All the samples with discrepant drug susceptibility result between molecular methods and phenotypic method were confirmed by DNA sequencing. Results A total of 1973 cases were enrolled in this study. The detection rates of Mycobacterium tuberculosis complex （MTBC） by MTBDRplus V2 and Xpert MTB/RIF were 27.67% and 27.98%, respectively. When setting MGIT culture result as a gold standard, the sensitivity and specificity of MTBDRplus V2 were 86.74% and 93.84%, and the sensitivity and specificity of Xpert MTB/RIF were 86.55% and 93.43%, respectively. For the detection of the resistance to rifampin, the sensitivity and specificity of MTBDRplus V2 were 94.34% and 96.62%, and the sensitivity and specificity of Xpert MTB/RIF were 88.68% and 95.96%, respectively. For the detection of the resistance to isoniazid, the sensitivity and specificity of MTBDRplus V2 were 77.38% and 98.02%, respectively. Conclusion MTBDRplus V2 and Xpert MTB/RIF can be used to detect MTBC in smear negative samples with satisfactory performance.展开更多
Background & Objectives: Emergence of drug resistant Tuberculosis (TB) is a major obstacle in the TB control programme of Bangladesh. This study was carried out to detect pre-extensively drug resistant TB (pre-XDR...Background & Objectives: Emergence of drug resistant Tuberculosis (TB) is a major obstacle in the TB control programme of Bangladesh. This study was carried out to detect pre-extensively drug resistant TB (pre-XDR-TB) cases among the multidrug resistant TB (MDR-TB) patients in Bangladesh, as the early detection of pre-XDR-TB can guide clinicians in the appropriate modification of MDR-TB treatment regimen with effective drugs to prevent treatment failure. Methodology: A total of 68 MDR-TB cases were enrolled in this study. Multiplex Real-time PCR was done to detect pre-XDR-TB cases directly from sputum samples of MDR-TB patients. Results: Out of 68 MDR-TB cases 11 (16.18%) cases were detected as pre-XDR-TB. The resistant profile of the 11 pre-XDR-TB revealed 9 (81.82%) cases of fluoroquinolone (FLQ) resistant pre-XDR-TB and 2 (18.18%) cases of injectable second line (ISL) agent resistant pre-XDR-TB. Out of 11 pre-XDR-TB cases 7 (63.64%) cases had history of taking treatment for MDR-TB regularly, 1 (9.09%) case had history of taking treatment for MDR-TB irregularly and 3 (27.27%) cases had no history of taking treatment for MDR-TB. Conclusion: This study encountered a high rate of pre-XDR-TB cases along with a significant number of primarily resistant bacilli which is of concern in the management of MDR-TB. It is evident that Bangladesh is in urgent need to device strategies for rapid and early detection of pre-XDR-TB in order to prevent treatment failure of MDR-TB cases and also to halt the progression of MDR-TB cases to extensively drug resistant TB (XDR-TB), which is not only difficult but also very expensive to treat.展开更多
Objective: To analyze characterization of the rpoBgene mutations of Mycobacterium tuber- culosis isolated from China and to explore the association of specific mutations conferring rifampicin (RIF) resistance with Bei...Objective: To analyze characterization of the rpoBgene mutations of Mycobacterium tuber- culosis isolated from China and to explore the association of specific mutations conferring rifampicin (RIF) resistance with Beijing genotype strains. Methods: Genotypic analysis of 3479M. tuberculosis isolatesincluding 402 RIF-resistantand 3077 RIF-susceptible isolated from the na- tional drug-resistant tuberculosis baseline survey was performed. Results: DNA sequencing analysis of the 81-bp RIF resistance determining region (RRDR) of the ropB gene revealed that 98.01% of RIF-resistant strains showedrpoBgene mutation, isolates with mutations at codon rpoB531, rpoB 526 and rpoB 516 were the most frequently. Analysis of the rpoB gene of 3077 RIF-susceptible strains revealed that 98.96% of the strains had no mutation. The distribution of mutation frequency at differentcritical codons in different regions of China was statistically significant (p = 0.001). There was no significant difference in the occurrence of mutations at critical codons between the rifampicin-resistant Bei-jing and non-Beijing isolates.Conclusion: About 98% of RIF-resistant strains isolated from China carry mutations in RRDR ofrpoB gene.Mutation profiles in RIF-resistantM. tuberculosis clinical isolates are variable depending on the different geographical regionsof China. The results provide valuable information in adopting new molecular methods for diagnosis of TB in China.展开更多
Tuberculosis (TB) remains one of the world’s deadliest diseases. Increasing rates of drug-resistant tuberculosis in Eastern Europe, Asia and sub-Saharan Africa now threaten to undermine the gains made by worldwide tu...Tuberculosis (TB) remains one of the world’s deadliest diseases. Increasing rates of drug-resistant tuberculosis in Eastern Europe, Asia and sub-Saharan Africa now threaten to undermine the gains made by worldwide tuberculosis control efforts. The region of Macedonia in North Greece is an entrance gate of thousands of immigrants, moving mainly from East European countries with high tuberculosis prevalence to Greece and the whole Europe. Our study determines the drug susceptibility pattern of new TB cases in the region of Macedonia, Greece. A total of 63 M. tuberculosis strains were isolated by cultivation between January 2012 and December 2014 in Macedonia, North Greece. After microscopic examination with Ziehl-Neelsen staining, clinical samples were simultaneously tested by two methods: conventional culture method on the Löwenstein-Jensen (L-J) slants for 8 weeks (at 370°C) and molecular method Genotype MTBDR plus (Hain-Lifescience). According to the study results, 2 out of 63 strains (3.2%) were resistant to both isoniazid (INH) and rifampicin (RMP). Additionally, 3 strains (4.8%) were INH mono-resistant. Statistical analysis demonstrated that there was no statistically significant difference in presence of resistance according to patients’ gender or origin (Greeks or immigrants). It is clear that the implementation of an efficient nationwide system for the surveillance, diagnosis and treatment of TB is essential. The best strategy in order to control, and prevent TB includes, first of, all a rapid diagnosis and initiation of treatment, something which is the most important for public health.展开更多
Drug susceptibility testing (DST) plays a pivotal role in TB patients’ management leading to the selection of most effective drugs. This study aimed to determine resistance patterns to first line anti-TB drugs in Myc...Drug susceptibility testing (DST) plays a pivotal role in TB patients’ management leading to the selection of most effective drugs. This study aimed to determine resistance patterns to first line anti-TB drugs in Mycobacterium tuberculosis isolates from re-treated patients from Sudan. A total of 239 sputum specimens were collected from smear positive re-treatment TB patients during the period from July 2009 to July 2010. Specimens were pre-treated according to Petroff method. The recovered isolates were tested for sensitivity to first line anti-TB drugs by the 1% proportion method. One hundred and forty three (143/239, 59.8%) mycobacterial isolates were successfully recovered. The majority (98.6%, 141/143) of the isolates were Mycobacterium tuberculosis complex strains. Two strains (2/143, 1.4%) were identified as RIF/INH-resistant MOTT, while fifty four isolates (38.3%, 54/141) were MDR. Multi- drug resistant Mycobacterium tuberculosis complex (MDR-TB) among re-treatment patients from national referral centers for tuberculosis diagnosis and management was considerably high in the study isolates.展开更多
The relationship between embB mutation of Mycobacterium tuberculosis and ethambutol （EMB） resistance of the clinical isolates of tuberculous patients in China was investigated by reversedot blot hybridization （RDBH...The relationship between embB mutation of Mycobacterium tuberculosis and ethambutol （EMB） resistance of the clinical isolates of tuberculous patients in China was investigated by reversedot blot hybridization （RDBH） in addition to evaluating the clinical value with application of PCR-RDBH technique to detect EMB resistance. In the present study, the genotypes of the 258 bp fragments of embB genes from 196 clinical isolates of M. tuberculosis were analysed with RDBH and DNA sequencing. It was demonstrated that 60 out of 91 phenotypically EMB-resistant isolates （65.9%） showed 5 types of missense mutations at codon 306 of embB gene, resulting in the replacement of the Met residue of the wild type strain with Val, Ile or Leu residues. In these mutations, the GTP mutation （38/91, 41.8% ） and the ATA mutation （16/91, 17.6% ） were the most encountered genotypes. The embB mutation at codon 306 could also be found in 69 isolates of phenotypically EMB-sensitive but resistant to other anti-tuberculous drugs, but no such gene mutation could be found in 36 strains of drug-sensitive isolates. Meanwhile, the concordance with the results of DNA sequencing fcr one wide-type probe and 5 probes for specific mutations was 100%. It was concluded that the EMB-resistance occurring in most M. tuberculosis is due to appearance of embB mutation at codon 306, and the PCR-RDBH assay was proved to be a rapid, simple and reliable method for the detection of gene mutations, which might be a good alternative for the drug-resistance screening.展开更多
Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and ass...Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner.This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples.Totally 4,395 milk samples were used to assesse the apparent(test)prevalence and incidence of bTB using the milk antibody ELISA.The association between levels of bTB milk antibody and milk quality was also evaluated.Milk and serum antibody tests showed a good correlation with a 87.5%(95%CI:61.7%,98.4)positive agreement and 98.7%(95%CI:95.4,99.8)negative agreement.The animal level lactoprevalence ranged from 0.3%(95%CI:0,1.2)to 33.3%(95%CI:26.6,40.6)in different farms and the incidence rate ranged from 0 head/cow-month(95%CI:0,0.02)to 0.04 head/cow-month(95%CI:0.02,0.07).Twenty percent of sampled farms met the criteria for bTB control in China.The prevalence on large-scale farms was lower(p<0.001)than on small farms.The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count(SCC),milk protein percentage(MPP)and percentage of total solids(TS).According to this research,milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.展开更多
Avian pathogenic Escherichia coli(APEC)belonging to extraintestinal pathogenic E.coli(ExPEC)can cause severe infections in extraintestinal tissues in birds and humans,such as the lungs and blood.MprA(microcin producti...Avian pathogenic Escherichia coli(APEC)belonging to extraintestinal pathogenic E.coli(ExPEC)can cause severe infections in extraintestinal tissues in birds and humans,such as the lungs and blood.MprA(microcin production regulation,locus A,herein renamed AbsR,a blood survival regulator),a member of the MarR(multiple antibiotic resistance regulator)transcriptional regulator family,governs the expression of capsule biosynthetic genes in human ExPEC and represents a promising druggable target for antimicrobials.However,a deep understanding of the AbsR regulatory mechanism as well as its regulon is lacking.In this study,we present a systems-level analysis of the APEC AbsR regulon using ChIP-Seq(chromatin immunoprecipitation sequencing)and RNA-Seq(RNA sequencing)methods.We found that AbsR directly regulates 99 genes and indirectly regulates 667 genes.Furthermore,we showed that:1)AbsR contributes to antiphagocytotic effects by macrophages and virulence in a mouse model for systemic infection by directly activating the capsular gene cluster;2)AbsR positively impacts biofilm formation via direct regulation of the T2SS(type II secretion system)but plays a marginal role in virulence;and 3)AbsR directly upregulates the acid tolerance signaling system EvgAS to withstand acid stress but is dispensable in ExPEC virulence.Finally,our data indicate that the role of AbsR in virulence gene regulation is relatively conserved in ExPEC strains.Altogether,this study provides a comprehensive analysis of the AbsR regulon and regulatory mechanism,and our data suggest that AbsR likely influences virulence primarily through the control of capsule production.Interestingly,we found that AbsR severely represses the expression of the type I-F CRISPR(clustered regularly interspaced short palindromic repeats)-Cas(CRISPR associated)systems,which could have implications in CRISPR biology and application.展开更多
Objective Mycobacterium avium （M. avium） and Mycobacterium intracellulare （M. intracellulare） are the major causative agents of nontuberculous mycobacteria （NTM）-related pulmonary infections. However, little is ...Objective Mycobacterium avium （M. avium） and Mycobacterium intracellulare （M. intracellulare） are the major causative agents of nontuberculous mycobacteria （NTM）-related pulmonary infections. However, little is known about the differences in drug susceptibility profiles between these two species. Methods A total of 393 NTM isolates were collected from Shanghai Pulmonary Disease Hospital. Sequencing of partial genes was performed to identify the strains at species level. The minimum inhibitory concentration （MIC） was used to evaluate the drug susceptibility against 20 antimicrobial agents. Variable number of tandem repeat （VNTR） typing was conducted to genotype these two species. Results A total of 173 （44.0%） M. avium complex （MAC） isolates were identified, including 41 （10.4%） M. avium isolates and 132 （33.6%） M. intracellulare isolates. Clarithromycin and amikacin were the two most effective agents against MAC isolates. The Hunter-Gaston Discriminatory Index （HGDI） values for VNTR typing of M. avium and M. intracellulare isolates were 0.993 and 0.995, respectively. Levofloxacin resistance was more common among the unclustered strains than among the clustered strains of M. intracellulare. Conclusion M. intrecellulare was the most common NTM species in China. Clarithromycin and amikacin had high antimicrobial activities against MAC. VNTR typing of MAC isolates revealed a high discriminatory power. Levofloxacin resistance was associated with unclustered strains of M. intracellulare.展开更多
We performed molecular identification of clinical isolates of Mycobacterium fortuitum（M. fortuitum） and conducted drug susceptibility testing to analyze the in vitro susceptibility of clinical M. fortuitum isolates ...We performed molecular identification of clinical isolates of Mycobacterium fortuitum（M. fortuitum） and conducted drug susceptibility testing to analyze the in vitro susceptibility of clinical M. fortuitum isolates and potential molecular mechanism conferring resistance to fluoroquinolone and macrolide drugs. The results showed that moxifloxacin had the highest in vitro activity against M. fortuitum, and most M. fortuitum isolates were resistant to clarithromycin and linezolid in China. The loss of genetic mutation in clarithromycin-and amikacin-resistant isolates indicates that some other intrinsic mechanism conferring clarithromycin and amikacin resistance plays an essential role in M. fortuitum infection.展开更多
Based on rpoB gene micro array as target gene, we are going to use gene chip technology to test 24 mycobacterium standard specimens, 8 non-mycobacterium specimens and 86 mycobacterium clinical isolated specimens. As a...Based on rpoB gene micro array as target gene, we are going to use gene chip technology to test 24 mycobacterium standard specimens, 8 non-mycobacterium specimens and 86 mycobacterium clinical isolated specimens. As a result, after mycobacterium and non-mycobacterium standard specimens were duplicated by PCR, mycobacterium standard specimens reproduced 360bp DNA fragments; on the other hand, non-mycobacterium specimens did not reproduce any fragments except for hemolytic streptococcus and corynebacterium pseudodiphtheriticum which had the same results as mycobacterium standard specimens. Sensitive test is able to detect lpg tuberculosis mycobacterium DNA. The probe test showed that, among 21 oligonucleotide probes, probe-M. fortuitum and M. marinum were cross-hybrid; the other probes were specific. We used the new method to identify 126 mycobacterium clinical isolated specimens. The test results of this new method matched with conventional method. In conclusion, compared to the traditional method, the use of rpob gene chip technology to identify mycobacterium species will be faster, more accurate and higher value in application.展开更多
Tuberculosis(TB),caused by Mycobacterium tuberculosis,continues to pose a significant threat to global health.The resilience of TB is amplified by a myriad of physical,biological,and biopharmaceutical barriers that ch...Tuberculosis(TB),caused by Mycobacterium tuberculosis,continues to pose a significant threat to global health.The resilience of TB is amplified by a myriad of physical,biological,and biopharmaceutical barriers that challenge conventional therapeutic approaches.This review navigates the intricate landscape of TB treatment,from the stealth of latent infections and the strength of granuloma formations to the daunting specters of drug resistance and altered gene expression.Amidst these challenges,traditional therapies often fail,contending with inconsistent bioavailability,prolonged treatment regimens,and socioeconomic burdens.Nanoscale Drug Delivery Systems(NDDSs)emerge as a promising beacon,ready to overcome these barriers,offering better drug targeting and improved patient adherence.Through a critical approach,we evaluate a spectrum of nanosystems and their efficacy against MTB both in vitro and in vivo.This review advocates for the intensification of research in NDDSs,heralding their potential to reshape the contours of global TB treatment strategies.展开更多
基金funded by the National Key R&D Program of China [2022YFC2305200]Natural Science Foundation of Xinjiang Uygur Autonomous Region [2021A01D145 and 2022D01A115]Applied Technology Research and Development Programing Project of Kashgar Prefecture [KS2021031 and KS2021034]。
文摘Objective China is among the 30 countries with a high burden of tuberculosis(TB)worldwide,and TB remains a public health concern.Kashgar Prefecture in the southern Xinjiang Autonomous Region is considered as one of the highest TB burden regions in China.However,molecular epidemiological studies of Kashgar are lacking.Methods A population-based retrospective study was conducted using whole-genome sequencing(WGS)to determine the characteristics of drug resistance and the transmission patterns.Results A total of 1,668 isolates collected in 2020 were classified into lineages 2(46.0%),3(27.5%),and 4(26.5%).The drug resistance rates revealed by WGS showed that the top three drugs in terms of the resistance rate were isoniazid(7.4%,124/1,668),streptomycin(6.0%,100/1,668),and rifampicin(3.3%,55/1,668).The rate of rifampicin resistance was 1.8%(23/1,290)in the new cases and 9.4%(32/340)in the previously treated cases.Known resistance mutations were detected more frequently in lineage 2 strains than in lineage 3 or 4 strains,respectively:18.6%vs.8.7 or 9%,P<0.001.The estimated proportion of recent transmissions was 25.9%(432/1,668).Multivariate logistic analyses indicated that sex,age,occupation,lineage,and drug resistance were the risk factors for recent transmission.Despite the low rate of drug resistance,drug-resistant strains had a higher risk of recent transmission than the susceptible strains(adjusted odds ratio,1.414;95%CI,1.023–1.954;P=0.036).Among all patients with drug-resistant tuberculosis(DR-TB),78.4%(171/218)were attributed to the transmission of DR-TB strains.Conclusion Our results suggest that drug-resistant strains are more transmissible than susceptible strains and that transmission is the major driving force of the current DR-TB epidemic in Kashgar.
文摘Setting: The Uganda National Tuberculosis Reference Laboratory (NTRL) in Kampala. Objective: The proportion of poor quality specimens received for drug susceptibility testing (DST) at the NTRL and factors contributing to poor specimen quality were assessed. Design: A cross-sectional study was conducted of sputum samples received at the NTRL from patients at high risk for multi-drug-resistant tuberculosis (MDR TB) during July-October 2013. Demographic, clinical, and bacte-riological data were abstracted from laboratory records. A poor quality sample failed to meet any one of four criteria: ≥3 milliliter (ml) volume, delivered within 72 hours, triple packaged, and non-salivary appearance. Results: Overall, 365 (64%) of 556 samples were of poor quality;89 (16%) were not triple packaged, 44 (8%) were <3 mls, 164 (30%) were not delivered on time, and 215 (39%) were salivary in appearance. Poor quality specimens were more likely to be collected during the eighth month of TB treatment (OR = 2.5, CI = 1.2 - 5.1), from the East or Northeast zones (OR = 2.2, CI = 1.1 - 4.8), and from patients who previously defaulted from treatment (OR = 1.9, CI = 1.1 - 3.2). Conclusion: The majority of sputum samples had poor quality. Additional efforts are needed to improve quality of samples collected at the end of treatment, from East and Northeast zones, and from patients who had previously defaulted.
基金supported by National Science Key Grant(2008ZX10003-009).
文摘Objective Tuberculosis remains a severe public health issue, and the Beijing family of mycobacterium tuberculosis （M. tuberculosis） is widespread in East Asia, especially in some areas in China, like Beijing and Tianjin. This study aimed at determining the mutation patterns of drug-resistant Beijing strains of M. tuberculosis isolated from Tianjin, China. Methods A total of 822 M. tuberculosis isolates were screened for drug resistance by an absolute concentration method and the genotype was identified by PCR. 169 drug-resistant isolates of the Beijing family were analyzed for the potential mutations in the rpoB, katG, inhA promoter region and in rpsL, rrs and embB genes, which are associated with resistance to rifampin （RFP）, isoniazid （INH）, streptomycin （SM） and ethambutol （EMB） respectively by PCR and DNA sequencing. Results Fifty-eight out of 63 RFP-resistant isolates were found to carry the mutations within the 81-bp RFP resistance determining region （RRDR） of the rpoB gene and the most frequent mutations occurred at codon 531 （44.4%）, 526 （28.6%）, and 516 （7.9%） respectively. 16 mutation pattems affecting 12 different codons around the RRDR of rpoB were found. Of 116 INH-resistant isolates, 56 （48.3%） had the mutation of katG 315 （AGC→ACC） （Ser→Thr）, 3 （2.6%） carried S315N （AGC→AAC） and 27 （16.0%） had the mutation of inhA-15A→T. 84 out of 122 SM-resistant isolates （68.9%） displayed mutations at the codons 43 or 88 with AAG→AGG （Lys→Arg） of the rpsL gene and 22 （18.0%） with the mutations at positions 513A→C, 516C→T or 905 A→G in the rrs gene. Of 34 EMB-resistant isolates, 6 had mutation with M306V （ATG→GTG）, 3 with M306I （ATG→ATT）, 1 with M306I （ATG→ATA）, 1 with D328Y （GAT→TAT）, 1 with V348L （GTC→CTC）, and 1 with G406S （GGC→AGC） in the embB gene. Conelusion These novel findings extended our understanding of resistance-related mutations in the Beijing strains of M. tuberculosis and may provide a scientific basis for development of new strategies for diagnosis and control of tuberculosis in China and other countries where Beijing strains are prevalent.
基金supported by Bill&Melinda Gates Foundation Tuberculosis Prevention and Control Project(2009-04-01)
文摘In order to evaluate the performance of a molecular Hain line probe assay （Hain LPA） for rapid detection of rifampicin and isoniazid resistance of Mycobocterium tuberculosis in China, 1612 smear positive patients were consecutively enrolled in this study. Smear positive sputum specimens were collected for Hain LPA and conventional drug susceptibility testing （DST）. The sensitivity and specificity of Hain LPA were analyzed by using conventional DST as golden reference. The sensitivity, specificity, positive predictive value {PPV） and negative predictive value （NPV） for rifampicin resistance detection were 88.33%, 97.66%, 81.54%, and 98.62%, respectively. The sensitivity, specificity, PPV and NPV for isoniazid resistance detection were 80.25%, 98.07%, 87.25%, and 96.78%, respectively. These findings suggested that Hain LPA can be an effective method worthy of broader use in China.
文摘Objective To compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis （PTB）. Methods Clinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and Xi＇an Chest Hospital from January to December in 2014. The sputum samples of smear negative PTB suspects were collected and decontaminated. The sediment was used to conduct MTBDRplus V2, Xpert MTB/RIF and drug susceptibility test （DST）. All the samples with discrepant drug susceptibility result between molecular methods and phenotypic method were confirmed by DNA sequencing. Results A total of 1973 cases were enrolled in this study. The detection rates of Mycobacterium tuberculosis complex （MTBC） by MTBDRplus V2 and Xpert MTB/RIF were 27.67% and 27.98%, respectively. When setting MGIT culture result as a gold standard, the sensitivity and specificity of MTBDRplus V2 were 86.74% and 93.84%, and the sensitivity and specificity of Xpert MTB/RIF were 86.55% and 93.43%, respectively. For the detection of the resistance to rifampin, the sensitivity and specificity of MTBDRplus V2 were 94.34% and 96.62%, and the sensitivity and specificity of Xpert MTB/RIF were 88.68% and 95.96%, respectively. For the detection of the resistance to isoniazid, the sensitivity and specificity of MTBDRplus V2 were 77.38% and 98.02%, respectively. Conclusion MTBDRplus V2 and Xpert MTB/RIF can be used to detect MTBC in smear negative samples with satisfactory performance.
文摘Background & Objectives: Emergence of drug resistant Tuberculosis (TB) is a major obstacle in the TB control programme of Bangladesh. This study was carried out to detect pre-extensively drug resistant TB (pre-XDR-TB) cases among the multidrug resistant TB (MDR-TB) patients in Bangladesh, as the early detection of pre-XDR-TB can guide clinicians in the appropriate modification of MDR-TB treatment regimen with effective drugs to prevent treatment failure. Methodology: A total of 68 MDR-TB cases were enrolled in this study. Multiplex Real-time PCR was done to detect pre-XDR-TB cases directly from sputum samples of MDR-TB patients. Results: Out of 68 MDR-TB cases 11 (16.18%) cases were detected as pre-XDR-TB. The resistant profile of the 11 pre-XDR-TB revealed 9 (81.82%) cases of fluoroquinolone (FLQ) resistant pre-XDR-TB and 2 (18.18%) cases of injectable second line (ISL) agent resistant pre-XDR-TB. Out of 11 pre-XDR-TB cases 7 (63.64%) cases had history of taking treatment for MDR-TB regularly, 1 (9.09%) case had history of taking treatment for MDR-TB irregularly and 3 (27.27%) cases had no history of taking treatment for MDR-TB. Conclusion: This study encountered a high rate of pre-XDR-TB cases along with a significant number of primarily resistant bacilli which is of concern in the management of MDR-TB. It is evident that Bangladesh is in urgent need to device strategies for rapid and early detection of pre-XDR-TB in order to prevent treatment failure of MDR-TB cases and also to halt the progression of MDR-TB cases to extensively drug resistant TB (XDR-TB), which is not only difficult but also very expensive to treat.
文摘Objective: To analyze characterization of the rpoBgene mutations of Mycobacterium tuber- culosis isolated from China and to explore the association of specific mutations conferring rifampicin (RIF) resistance with Beijing genotype strains. Methods: Genotypic analysis of 3479M. tuberculosis isolatesincluding 402 RIF-resistantand 3077 RIF-susceptible isolated from the na- tional drug-resistant tuberculosis baseline survey was performed. Results: DNA sequencing analysis of the 81-bp RIF resistance determining region (RRDR) of the ropB gene revealed that 98.01% of RIF-resistant strains showedrpoBgene mutation, isolates with mutations at codon rpoB531, rpoB 526 and rpoB 516 were the most frequently. Analysis of the rpoB gene of 3077 RIF-susceptible strains revealed that 98.96% of the strains had no mutation. The distribution of mutation frequency at differentcritical codons in different regions of China was statistically significant (p = 0.001). There was no significant difference in the occurrence of mutations at critical codons between the rifampicin-resistant Bei-jing and non-Beijing isolates.Conclusion: About 98% of RIF-resistant strains isolated from China carry mutations in RRDR ofrpoB gene.Mutation profiles in RIF-resistantM. tuberculosis clinical isolates are variable depending on the different geographical regionsof China. The results provide valuable information in adopting new molecular methods for diagnosis of TB in China.
文摘Tuberculosis (TB) remains one of the world’s deadliest diseases. Increasing rates of drug-resistant tuberculosis in Eastern Europe, Asia and sub-Saharan Africa now threaten to undermine the gains made by worldwide tuberculosis control efforts. The region of Macedonia in North Greece is an entrance gate of thousands of immigrants, moving mainly from East European countries with high tuberculosis prevalence to Greece and the whole Europe. Our study determines the drug susceptibility pattern of new TB cases in the region of Macedonia, Greece. A total of 63 M. tuberculosis strains were isolated by cultivation between January 2012 and December 2014 in Macedonia, North Greece. After microscopic examination with Ziehl-Neelsen staining, clinical samples were simultaneously tested by two methods: conventional culture method on the Löwenstein-Jensen (L-J) slants for 8 weeks (at 370°C) and molecular method Genotype MTBDR plus (Hain-Lifescience). According to the study results, 2 out of 63 strains (3.2%) were resistant to both isoniazid (INH) and rifampicin (RMP). Additionally, 3 strains (4.8%) were INH mono-resistant. Statistical analysis demonstrated that there was no statistically significant difference in presence of resistance according to patients’ gender or origin (Greeks or immigrants). It is clear that the implementation of an efficient nationwide system for the surveillance, diagnosis and treatment of TB is essential. The best strategy in order to control, and prevent TB includes, first of, all a rapid diagnosis and initiation of treatment, something which is the most important for public health.
文摘Drug susceptibility testing (DST) plays a pivotal role in TB patients’ management leading to the selection of most effective drugs. This study aimed to determine resistance patterns to first line anti-TB drugs in Mycobacterium tuberculosis isolates from re-treated patients from Sudan. A total of 239 sputum specimens were collected from smear positive re-treatment TB patients during the period from July 2009 to July 2010. Specimens were pre-treated according to Petroff method. The recovered isolates were tested for sensitivity to first line anti-TB drugs by the 1% proportion method. One hundred and forty three (143/239, 59.8%) mycobacterial isolates were successfully recovered. The majority (98.6%, 141/143) of the isolates were Mycobacterium tuberculosis complex strains. Two strains (2/143, 1.4%) were identified as RIF/INH-resistant MOTT, while fifty four isolates (38.3%, 54/141) were MDR. Multi- drug resistant Mycobacterium tuberculosis complex (MDR-TB) among re-treatment patients from national referral centers for tuberculosis diagnosis and management was considerably high in the study isolates.
文摘The relationship between embB mutation of Mycobacterium tuberculosis and ethambutol （EMB） resistance of the clinical isolates of tuberculous patients in China was investigated by reversedot blot hybridization （RDBH） in addition to evaluating the clinical value with application of PCR-RDBH technique to detect EMB resistance. In the present study, the genotypes of the 258 bp fragments of embB genes from 196 clinical isolates of M. tuberculosis were analysed with RDBH and DNA sequencing. It was demonstrated that 60 out of 91 phenotypically EMB-resistant isolates （65.9%） showed 5 types of missense mutations at codon 306 of embB gene, resulting in the replacement of the Met residue of the wild type strain with Val, Ile or Leu residues. In these mutations, the GTP mutation （38/91, 41.8% ） and the ATA mutation （16/91, 17.6% ） were the most encountered genotypes. The embB mutation at codon 306 could also be found in 69 isolates of phenotypically EMB-sensitive but resistant to other anti-tuberculous drugs, but no such gene mutation could be found in 36 strains of drug-sensitive isolates. Meanwhile, the concordance with the results of DNA sequencing fcr one wide-type probe and 5 probes for specific mutations was 100%. It was concluded that the EMB-resistance occurring in most M. tuberculosis is due to appearance of embB mutation at codon 306, and the PCR-RDBH assay was proved to be a rapid, simple and reliable method for the detection of gene mutations, which might be a good alternative for the drug-resistance screening.
基金the Natural Science Foundation of China(U21A20259)National Key Research and Development Program of Ningxia Hui Autonomous Region(2021BEF02028)+1 种基金the Natural Science Foundation of Hubei Province(2021CFA016)China Agriculture Research System of MOF and MARA and Basic and technical innovation team for prevention and control of bovine disease.
文摘Bovine tuberculosis(bTB)is a chronic zoonotic disease that is endemic in China.Current in-vitro tests for bTB are mainly based on blood assays.Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner.This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples.Totally 4,395 milk samples were used to assesse the apparent(test)prevalence and incidence of bTB using the milk antibody ELISA.The association between levels of bTB milk antibody and milk quality was also evaluated.Milk and serum antibody tests showed a good correlation with a 87.5%(95%CI:61.7%,98.4)positive agreement and 98.7%(95%CI:95.4,99.8)negative agreement.The animal level lactoprevalence ranged from 0.3%(95%CI:0,1.2)to 33.3%(95%CI:26.6,40.6)in different farms and the incidence rate ranged from 0 head/cow-month(95%CI:0,0.02)to 0.04 head/cow-month(95%CI:0.02,0.07).Twenty percent of sampled farms met the criteria for bTB control in China.The prevalence on large-scale farms was lower(p<0.001)than on small farms.The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count(SCC),milk protein percentage(MPP)and percentage of total solids(TS).According to this research,milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.
基金supported by the National Natural Science Foundation of China Young Scholars Project(31902242)the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences(2017–2020)。
文摘Avian pathogenic Escherichia coli(APEC)belonging to extraintestinal pathogenic E.coli(ExPEC)can cause severe infections in extraintestinal tissues in birds and humans,such as the lungs and blood.MprA(microcin production regulation,locus A,herein renamed AbsR,a blood survival regulator),a member of the MarR(multiple antibiotic resistance regulator)transcriptional regulator family,governs the expression of capsule biosynthetic genes in human ExPEC and represents a promising druggable target for antimicrobials.However,a deep understanding of the AbsR regulatory mechanism as well as its regulon is lacking.In this study,we present a systems-level analysis of the APEC AbsR regulon using ChIP-Seq(chromatin immunoprecipitation sequencing)and RNA-Seq(RNA sequencing)methods.We found that AbsR directly regulates 99 genes and indirectly regulates 667 genes.Furthermore,we showed that:1)AbsR contributes to antiphagocytotic effects by macrophages and virulence in a mouse model for systemic infection by directly activating the capsular gene cluster;2)AbsR positively impacts biofilm formation via direct regulation of the T2SS(type II secretion system)but plays a marginal role in virulence;and 3)AbsR directly upregulates the acid tolerance signaling system EvgAS to withstand acid stress but is dispensable in ExPEC virulence.Finally,our data indicate that the role of AbsR in virulence gene regulation is relatively conserved in ExPEC strains.Altogether,this study provides a comprehensive analysis of the AbsR regulon and regulatory mechanism,and our data suggest that AbsR likely influences virulence primarily through the control of capsule production.Interestingly,we found that AbsR severely represses the expression of the type I-F CRISPR(clustered regularly interspaced short palindromic repeats)-Cas(CRISPR associated)systems,which could have implications in CRISPR biology and application.
基金supported by a grant from the National Basic Research Program of China 2014CB744403the National Science and Technology Major Project 2014ZX100030002
文摘Objective Mycobacterium avium （M. avium） and Mycobacterium intracellulare （M. intracellulare） are the major causative agents of nontuberculous mycobacteria （NTM）-related pulmonary infections. However, little is known about the differences in drug susceptibility profiles between these two species. Methods A total of 393 NTM isolates were collected from Shanghai Pulmonary Disease Hospital. Sequencing of partial genes was performed to identify the strains at species level. The minimum inhibitory concentration （MIC） was used to evaluate the drug susceptibility against 20 antimicrobial agents. Variable number of tandem repeat （VNTR） typing was conducted to genotype these two species. Results A total of 173 （44.0%） M. avium complex （MAC） isolates were identified, including 41 （10.4%） M. avium isolates and 132 （33.6%） M. intracellulare isolates. Clarithromycin and amikacin were the two most effective agents against MAC isolates. The Hunter-Gaston Discriminatory Index （HGDI） values for VNTR typing of M. avium and M. intracellulare isolates were 0.993 and 0.995, respectively. Levofloxacin resistance was more common among the unclustered strains than among the clustered strains of M. intracellulare. Conclusion M. intrecellulare was the most common NTM species in China. Clarithromycin and amikacin had high antimicrobial activities against MAC. VNTR typing of MAC isolates revealed a high discriminatory power. Levofloxacin resistance was associated with unclustered strains of M. intracellulare.
基金supported by a grant from the National Basic Research Program of China 2014CB744403National Science and Technology Major Project 2014ZX100030002
文摘We performed molecular identification of clinical isolates of Mycobacterium fortuitum（M. fortuitum） and conducted drug susceptibility testing to analyze the in vitro susceptibility of clinical M. fortuitum isolates and potential molecular mechanism conferring resistance to fluoroquinolone and macrolide drugs. The results showed that moxifloxacin had the highest in vitro activity against M. fortuitum, and most M. fortuitum isolates were resistant to clarithromycin and linezolid in China. The loss of genetic mutation in clarithromycin-and amikacin-resistant isolates indicates that some other intrinsic mechanism conferring clarithromycin and amikacin resistance plays an essential role in M. fortuitum infection.
基金supported by the South African Medical Research Councilthe National Health Laboratory Services Research Trust and the University of the Witwatersr and Health Sciences Faculty Research Committee
文摘Based on rpoB gene micro array as target gene, we are going to use gene chip technology to test 24 mycobacterium standard specimens, 8 non-mycobacterium specimens and 86 mycobacterium clinical isolated specimens. As a result, after mycobacterium and non-mycobacterium standard specimens were duplicated by PCR, mycobacterium standard specimens reproduced 360bp DNA fragments; on the other hand, non-mycobacterium specimens did not reproduce any fragments except for hemolytic streptococcus and corynebacterium pseudodiphtheriticum which had the same results as mycobacterium standard specimens. Sensitive test is able to detect lpg tuberculosis mycobacterium DNA. The probe test showed that, among 21 oligonucleotide probes, probe-M. fortuitum and M. marinum were cross-hybrid; the other probes were specific. We used the new method to identify 126 mycobacterium clinical isolated specimens. The test results of this new method matched with conventional method. In conclusion, compared to the traditional method, the use of rpob gene chip technology to identify mycobacterium species will be faster, more accurate and higher value in application.
基金support from the S˜ao Paulo Research Foundation(FAPESP,Brazil),Grant numbers#01664-1,#2022/02661-3 and#2020/16573-3,respectivelyNational Council for Scientific and Technological Development(CNPq):Productivity Research Fellows(PQ CNPq):305408/2022-4This study is part of the National Institute of Science and Technology in Pharmaceutical Nanotechnology:a transdisciplinary approach,INCT-NANOFARMA,which is supported by S˜ao Paulo Research Foundation(FAPESP,Brazil)Grant#2014/50928-2,and by“Conselho Nacional de Desenvolvimento Científico e Tecnol′ogico”(CNPq,Brazil)Grant#465687/2014-8.Prof.H.A.Santos acknowledges financial support from the Research Council of Finland(Grant No.331151)and the UMCG Research Funds.
文摘Tuberculosis(TB),caused by Mycobacterium tuberculosis,continues to pose a significant threat to global health.The resilience of TB is amplified by a myriad of physical,biological,and biopharmaceutical barriers that challenge conventional therapeutic approaches.This review navigates the intricate landscape of TB treatment,from the stealth of latent infections and the strength of granuloma formations to the daunting specters of drug resistance and altered gene expression.Amidst these challenges,traditional therapies often fail,contending with inconsistent bioavailability,prolonged treatment regimens,and socioeconomic burdens.Nanoscale Drug Delivery Systems(NDDSs)emerge as a promising beacon,ready to overcome these barriers,offering better drug targeting and improved patient adherence.Through a critical approach,we evaluate a spectrum of nanosystems and their efficacy against MTB both in vitro and in vivo.This review advocates for the intensification of research in NDDSs,heralding their potential to reshape the contours of global TB treatment strategies.
