BACKGROUND:To analyze the epidemiological characteristics of the SARS-CoV-2 infection and reinfection associated with the emergence of Omicron variant in Healthcare workers (HCWs). METHODS:We enrolled 760 HCWs who received 2-4 vaccination doses of COVID-19 and followed by BA.5/BF.7 and/or XBB.1.5 breakthrough infections between December 2022 and July 2023. Serum sample from each individual were collected approximately 1,3 and 6 months after last exposure. IgM, IgG and Total antibodies against SARS-CoV-2 were measured by chemiluminescent immunoassay. Meanwhile, we created an Enterprise WeChat link for HCWs to self-report SARS-CoV-2 infections, symptoms and post COVID-19 conditions. RESULTS:Our study revealed that the reinfection rate among HCWs reached 26.1%. The main symptoms were fever (91.2% vs 60.1%), cough (78.8% vs 58.0%), and sore throat (75.4% vs 59.6%) during infection and reinfection in Omicron BA.5/BF.7 and XBB.1.5 wave, and the interval for reinfection ranged from 91 to 210 days (median 152). Fatigue (23.6%), memory loss (18.8%) and coughing (18.6%) were the most prevalent long COVID symptoms, with a higher prevalence among female HCWs. CONCLUSIONS:HCWs reinfection with SARS-CoV-2 causes milder symptoms, but high reinfection rate and short intervals. Strengthen infection prevention and control is crucial to mitigating infection risk and improving health services.

In China, the proportion of HIV-1 infections due to men who have sex with men (MSM) has increased rapidly. More and more new subtypes are found among the MSM population besides known CRF01_AE, CRF07_BC, and B. The co-circulation of several HIV subtypes in the same population provides the opportunity to develop a new circulating recombinant form (CRF) and unique recombinant form (URF). Here we reported two new URFs from two HIV-1 positive subjects infected through homosexual contact in Hebei, China. Phylogenetic and recombinant analyses based on the near full-length genome (NFLG) of the two URFs are the second-generation recombinant strains that originated from B, CRF01_AE, and CRF07_BC. The CRF01_AE segments in the genome of two URFs originated from cluster 4 of CRF01_AE strains, while the CRF07_BC segments were clustered with 07BC_N in the phylogenetic tree. The emergence of the novel CRF01_AE/CRF07_BC and CRF01_AE/B recombinant forms indicated the importance of the continuous monitoring of the HIV-1 epidemic and new URFs among the MSM population.

The ongoing emergence of SARS-CoV-2 variants poses challenges to the immunity induced by infections and vaccination. We conduct a 6 -month longitudinal evaluation of antibody binding and neutralization of sera from individuals with six different combinations of vaccination and infection against BA.5, XBB.1.5, EG.5.1, and BA.2.86. We find that most individuals produce spike -binding IgG or neutralizing antibodies against BA.5, XBB.1.5, EG.5.1, and BA.2.86 2 months after infection or vaccination. However, compared to ancestral strain and BA.5 variant, XBB.1.5, EG.5.1, and BA.2.86 exhibit comparable but significant immune evasion. The spike -binding IgG and neutralizing antibody titers decrease in individuals without additional antigen exposure, and <50% of individuals neutralize XBB.1.5, EG.5.1, and BA.2.86 during the 6 -month followup. Approximately 57% of the 107 followed up individuals experienced an additional infection, leading to improved binding IgG and neutralizing antibody levels against these variants. These findings provide insights into the impact of SARS-CoV-2 variants on immunity following repeated exposure.

There is a paucity of data on hybrid immunity (vaccination plus breakthrough infection [BI]), especially cell-mediated responses to Omicron among immunosuppressed patients. We aim to investigate humoral and cellular responses to Omicron BA.4/5 among people living with HIV (PLWH) with/without BIs, the most prevalent variant of concern after the reopening of China. Based on our previous study, we enrolled 77 PLWH with baseline immune status of severe acute respiratory syndrome coronavirus 2 specific antibodies after inactivated vaccination. "Correlates of protection," including serological immunoassays, T cell phenotypes and memory B cells (MBC) were determined in PLWH without and with BI, together with 16 PLWH with reinfections. Higher inhibition rate of neutralizing antibodies (NAb) against BA.4/5 was elicited among PLWH with BI than those without. Omicron-reactive IL4+ CD8+ T cells were significantly elevated in PLWH experienced postvaccine infection contrasting with those did not. NAb towards wild type at baseline was associated with prolonged negative conversion time for PLWH whereas intermediate MBCs serve as protecting effectors. We uncovered that hybrid immunity intensified more protection on BA.4/5 than vaccination did. Strengthened surveillance on immunological parameters and timely clinical intervention on PLWH deficient in protection would reduce the severity and mortality in the context of coexistence with new Omicron subvariants.

The number of individuals infected with HIV-1 among men who have sex with men (MSM) has risen rapidly in recent years in China, and the subtypes CRF01_AE, CRF07_BC, and B, as well as many novel unique recombinant forms (URFs) are prevalent among them. Co-circulation of strains among MSM populations allows the generation of circulating recombinant forms (CRFs) and URFs. In this study, we identified two new URFs from two HIV-1-positive subjects who were infected through homosexual contact in Hebei, China. Analysis of near-full-length genome sequences, using phylogenetic and recombination analysis showed that the two URFs originated from CRF01_AE, CRF07_BC, and B, and CRF01_AE segments in the backbone of the URFs were derived from cluster 4 of CRF01_AE. The CRF07_BC segments of two URFs were clustered with 07BC_N in a phylogenetic tree. The identification of novel URFs with complex genomic structures shows that it is necessary to strengthen surveillance of HIV-1 variants in MSM populations in this region.

The continued emergence of SARS-CoV-2 variants of concern (VOCs) has raised great challenges for epidemic prevention and control. A rapid, sensitive, and on-site SARS-CoV-2 genotyping technique is urgently needed for individual diagnosis and routine surveillance. Here, a field-deployable ultrasensitive CRISPR-based diagnostics system, called Chemical additive-Enhanced Single-Step Accurate CRISPR/Cas13 Testing system (CESSAT), for simultaneous screening of SARS-CoV-2 and its five VOCs (Alpha, Beta, Gamma, Delta, and Omicron) within 40 min was reported. In this system, a single-step reverse transcription recombinase polymerase amplification-CRISPR/Cas13a assay was incorporated with optimized extraction-free viral lysis and reagent lyophilization, which could eliminate complicated sample processing steps and rigorous reagent storage conditions. Remarkably, 10% glycine as a chemical additive could improve the assay sensitivity by 10 times, making the limit of detection as low as 1 copy/μL (5 copies/reaction). A compact optic fiber-integrated smartphone-based device was developed for sample lysis, assay incubation, fluorescence imaging, and result interpretation. CESSAT could specifically differentiate the synthetic pseudovirus of SARS-CoV-2 and its five VOCs. The genotyping results for 40 clinical samples were in 100% concordance with standard method. We believe this simple but efficient enhancement strategy can be widely incorporated with existing Cas13a-based assays, thus leading a substantial progress in the development and application of rapid, ultrasensitive, and accurate nucleic acid analysis technology.

Abstract Background Evidence shows that genetic factors play important roles in the severity of coronavirus disease 2019 (COVID-19). Sulfatase modifying factor 1 (SUMF1) gene is involved in alveolar damage and systemic inflammatory response. Therefore, we speculate that it may play a key role in COVID-19. Results We found that rs794185 was significantly associated with COVID-19 severity in Chinese population, under the additive model after adjusting for gender and age (for C allele = 0.62, 95% CI = 0.44–0.88, P = 0.0073, logistic regression). And this association was consistent with this in European population Genetics Of Mortality In Critical Care (GenOMICC: OR for C allele = 0.94, 95% CI = 0.90–0.98, P = 0.0037). Additionally, we also revealed a remarkable association between rs794185 and the prothrombin activity (PTA) in subjects (P = 0.015, Generalized Linear Model). Conclusions In conclusion, our study for the first time identified that rs794185 in SUMF1 gene was associated with the severity of COVID-19.

This study aimed to investigate the immunogenicity to SARS‐CoV‐2 and evasive subvariants BA.4/5 in people living with HIV (PLWH) following a third booster shot of inactivated SARS‐CoV‐2 vaccine. We conducted a cross‐sectional study in 318 PLWH and 241 healthy controls (HC) using SARS‐CoV‐2 immunoassays. Vaccine‐induced immunological responses were compared before and after the third dose. Serum levels of IgG anti‐RBD and inhibition rate of NAb were significantly elevated at the “post‐third dose” sampling time compared with the pre‐third dose in PLWH, but were relatively decreased in contrast with those of HCs. Induced humoral and cellular responses attenuated over time after triple‐dose vaccination. The neutralizing capacity against BA.4/5 was also intensified but remained below the positive inhibition threshold. Seropositivity of SARS‐CoV‐2‐specific antibodies in PLWH was prominently lower than that in HC. We also identified age, CD4 cell counts, time after the last vaccination, and WHO staging type of PLWH as independent factors associated with the seropositivity of antibodies. PLWH receiving booster shot of inactivated vaccines generate higher antibody responses than the second dose, but lower than that in HCs. Decreased anti‐BA.4/5 responses than that of WT impede the protective effect of the third dose on Omicron prevalence.

Background To date, several types of laboratory tests for coronavirus disease 2019 (COVID-19) diagnosis have been developed. However, the clinical importance of serum severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antigen (N-Ag) remains to be fully elucidated. In this study, we sought to investigate the value of serum SARS-CoV-2 N-Ag for COVID-19 diagnosis and to analyze N-Ag characteristics in COVID-19 individuals. Methods Serum samples collected from 215 COVID-19 patients and 65 non-COVID-19 individuals were used to quantitatively detect N-Ag via chemiluminescent immunoassay according to the manufacturer’s instructions. Results The sensitivity and specificity of the N-Ag assay were 64.75% (95% confidence interval (95% CI) [55.94–72.66%]) and 100% (95% CI [93.05–100.00%]), respectively, according to the cut-off value recommended by the manufacturer. The receiver operating characteristic (ROC) curve showed a sensitivity of 100.00% (95% CI [94.42–100.00%]) and a specificity of 71.31% (95% CI [62.73–78.59%]). The positive rates and levels of serum SARS-CoV-2 N-Ag were not related to sex, comorbidity status or disease severity of COVID-19 (all P < 0.001). Compared with RT‒PCR, there was a lower positive rate of serum N-Ag for acute COVID-19 patients (P < 0.001). The positive rate and levels of serum SARS-CoV-2 N-Ag in acute patients were significantly higher than those in convalescent patients (all P < 0.001). In addition, the positive rate of serum SARS-CoV-2 N-Ag in acute COVID-19 patients was higher than that of serum antibodies (IgM, IgG, IgA and neutralizing antibodies (Nab)) against SARS-CoV-2 (all P < 0.001). However, the positive rate of serum SARS-CoV-2 N-Ag in convalescent COVID-19 patients was significantly lower than that of antibodies (all P < 0.001). Conclusion Serum N-Ag can be used as a biomarker for early COVID-19 diagnosis based on appropriate cut-off values. In addition, our study also demonstrated the relationship between serum N-Ag and clinical characteristics.

•CRF123_0107 was been identified among MSM in Hebei province. •CRF123_0107 was composed of CRF01_AE and CRF07_BC. •The tMCRA of CRF123_0107 was predicted around 2016 and 2014.

新型冠状病毒肺炎为2019年新发急性呼吸道传染病,目前已成为全球重大的公共卫生事件,其发生发展是机体内外多种因素共同作用的结果.当暴露于同一感染源时,不同个体对新冠病毒的易感性和感染后病情的严重程度不同,个体的遗传背景不同是其中一个重要原因.该文总结了与新冠肺炎发病有关的宿主遗传变异基因,为新冠病毒肺炎的预防和治疗提供新的思路.

目的 比较不同原理抗体检测试剂对新冠疑似病例诊断的准确性,对新冠疑似病例提出高效的排查方案,进一步为建立高风险人群的临床筛查路径提供科学依据.方法 对76例由于IgM抗体初检阳性被转入定点医院隔离观察的新冠疑似病例,进行鼻咽拭子核酸检测,血清微量病毒中和抗体和3种市售不同原理抗体检测试剂检测,以及肺部CT检查,结合临床症状等信息,综合判断新冠确诊或排除情况,并将3种血清学抗体检测试剂与临床判断结果进行对比分析,比较3种检测方法结果的差异.结果 通过综合判断,76例疑似病例中有3例为确诊病例,73例为排除病例.与临床确诊/排除结果比较,3种血清学抗体检测方法中,化学发光总抗体对3例病例入院不同时间点共9份样本均能检出,对73例排除病例入院第1天采集样本的检测特异性为97.26％,高于化学发光法IgM/IgG和胶体金法IgM/IgG单独检测(入院第1 d样本检测特异性均为73.97％).结论 化学发光法检测新冠总抗体具有高灵敏度和高特异性,可以用于疑似病例抗体检测的初筛.针对重点人群筛查,应首先进行2019-nCoV核酸检测,若核酸检测阴性,则采用检测血清总抗体为主要指标的筛查路径.

While some individuals infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) present mild-to-severe disease, many SARS-CoV-2-infected individuals are asymptomatic. We sought to identify the distinction of immune response between asymptomatic and moderate patients. We performed single-cell transcriptome and T-cell/B-cell receptor (TCR/BCR) sequencing in 37 longitudinal collected peripheral blood mononuclear cell samples from asymptomatic, moderate, and severe patients with healthy controls. Asymptomatic patients displayed increased CD56briCD16- natural killer (NK) cells and upregulation of interferon-gamma in effector CD4+ and CD8+ T cells and NK cells. They showed more robust TCR clonal expansion, especially in effector CD4+ T cells, but lack strong BCR clonal expansion compared to moderate patients. Moreover, asymptomatic patients have lower interferon-stimulated genes (ISGs) expression in general but large interpatient variability, whereas moderate patients showed various magnitude and temporal dynamics of the ISGs expression across multiple cell populations but lower than a patient with severe disease. Our data provide evidence of different immune signatures to SARS-CoV-2 in asymptomatic infections.

We quantified the serum levels of 34 cytokines/chemokines in 30 patients with SARS-CoV-2 infection. Elevated levels of IP-10 and IL-7 were detected in the acute and convalescent stages of the infection and were highly associated with disease severity.

Recent studies have characterized the single-cell immune landscape of host immune response of coronavirus disease 2019 (COVID-19), specifically focus on the severe condition. However, the immune response in mild or even asymptomatic patients remains unclear. Here, we performed longitudinal single-cell transcriptome sequencing and T cell/B cell receptor sequencing on 3 healthy donors and 10 COVID-19 patients with asymptomatic, moderate, and severe conditions. We found asymptomatic patients displayed distinct innate immune responses, including increased CD56briCD16− NK subset, which was nearly missing in severe condition and enrichment of a new Th2-like cell type/state expressing a ciliated cell marker. Unlike that in moderate condition, asymptomatic patients lacked clonal expansion of effector CD8+ T cells but had a robust effector CD4+ T cell clonal expansion, coincide with previously detected SARS-CoV-2-reactive CD4+ T cells in unexposed individuals. Moreover, NK and effector T cells in asymptomatic patients have upregulated cytokine related genes, such as IFNG and XCL2 . Our data suggest early innate immune response and type I immunity may contribute to the asymptomatic phenotype in COVID-19 disease, which could in turn deepen our understanding of severe COVID-19 and guide early prediction and therapeutics. ### Competing Interest Statement The authors have declared no competing interest.

To the Editor: The epidemic caused by 2019 novel coronavirus (2019-nCoV) has drawn public attention.[1] Huge infected population and enormous economic loss make it the urgent public health event to deal with. Confirmatory test targeting virus RNA was established at the early stage of outbreak and then used for 2019-nCoV infection diagnosis.[2] However, high risk of laboratory infection, high-qualified personnel, and strict operation condition hampered its application into primary hospitals and community clinics.[3] In this study, the serum immunoglobulin (Ig) M and IgG antibodies were detected in 2019-nCoV confirmed cases of different stages. Furthermore, three different immunological assays, chemiluminescent immunoassay (CLIA), gold immunochromatographic assay (GICA), and enzyme-linked immunosorbent assay (ELISA) were used for IgM and IgG detection. A total of 22 confirmed patients were admitted to the Fifth Hospital of Shijiazhuang, the designated hospital for 2019-nCoV infection, from January 21st to February 24th, 2020. All patients were confirmed by reverse-transcription polymerase-chain-reaction assay (2019-nCoV RNA Test Kit, Daan Gene Company, China) for nasal and pharyngeal swab specimens, and were treated according to the national diagnosis and treatment plan.[4] This study was approved by the Ethics Commission of the Fifth Hospital of Shijiazhuang.The authors certify that they have obtained all appropriate patient consent forms. The clinical features and laboratory results were collected from electronic medical records. Typical ground-glass opacity in lung was observed in computed tomography scan results of all patients. Of the 22 patients, eight were females and 14 were males. Eleven patients had recent history of travel to epidemic areas, and the remaining ten had close contacts with their family members, who were confirmed to be infected by 2019-nCoV. The patients aged from 4 to 72 years, with the median age of 40 years. Most of the patients received oxygen therapy and anti-virus medication. Currently, all patients had recovered and discharged from hospital. Due to the late delivery of the testing kits, some serum samples were not available. A total of 37 serum samples from 22 patients were obtained, of which ten came from the early stage (1–7 days after the onset of infection), 13 from the middle stage (8–14 days after the onset of infection), and 14 from the late stage (14–24 days after the onset of infection). The level of serum IgM and IgG antibodies were detected using three different commercial testing kits (CLIA, GICA, and ELISA) developed by the Beier Bioengineering Company (Beijing, China), which targeted the spike (S) and nucleocapsid (N) proteins of 2019-nCoV. For CLIA, samples with an concentration ≥8 arbitrary unit/mL were considered positive. For GICA, positive results showed the appearance of both control line and testing line. For ELISA, the absorbance at 450 nm (A450 nm) of each well was determined within 10 min using a microplate reader, and the cut-off value was 0.10+Anegative control. A value higher than the cut-off value was considered a positive result. All tests were conducted in the Laboratory of the Fifth Hospital of Shijiazhuang, according to the manufacturer's instructions and the technical guidelines for laboratory testing of new coronavirus infected pneumonia (second edition).[5] As shown in Table 1, at the early, middle and late stages of infection, the serum IgM antibody was detected in 6/10, 7/13, and 11/14 of cases, respectively (at least one immunoassay was positive). Meanwhile, at the early and middle stages of infection, 5/10 and 10/13 cases demonstrated positive serum IgG results, whereas the serum IgG was detected in all cases (14/14) when it came to the late stage of infection.Table 1: The serum IgM and IgG levels in 2019-nCoV infected patients detected by different methods.CLIA, GICA, and ELISA are important detection methods in clinical immunological diagnosis. Nevertheless, the positive rates of the three methods differed in detection of 2019-nCoV infection. GICA possessed a relatively higher positive rate in serum IgM detection (5/10, 5/13, and 9/14 in the early, middle, and late stages, respectively) and ELISA exhibited a comparatively higher positive rate in serum IgG testing (4/10, 8/13, and 12/14 in the early, middle, and late stages, respectively). Detection of serum specific antibodies, IgM and IgG, is another crucial evidence for the diagnosis of infection. Easy operation, low work environmental requirement, and accessibility of blood samples make serological antibody test another choice for rapid screening and diagnosis of 2019-nCoV infection. The combination of GICA for serum IgM and ELISA for serum IgG might be an effective way for early screening and diagnosis for 2019-nCoV infection. Acknowledgements The authors thank the staff of the Fifth Hospital of Shijiazhuang for their contribution to this study. The authors appreciate the support provided by the Center for Disease Control and Prevention in Hebei Province. Conflicts of interest None.

OBJECTIVES:Multidrug-resistant tuberculosis (MDR-TB) is a major public-health problem in China. However, there is little information on the molecular characterisation of clinical MDR-TB isolates in Hebei Province. METHODS:In this study, 123 MDR-TB isolates were identified in sputum cultures using traditional drug susceptibility testing. The isolates were analysed for mutations in seven genes associated with resistance to antituberculous four drugs: katG and inhA promoter for isoniazid (INH); rpoB for rifampicin (RIF); gyrA and gyrB for ofloxacin (OFLX); and rrs and eis promoter for kanamycin (KAN). All strains were genotyped by spoligotyping and 15-loci MIRU-VNTR analysis. RESULTS:A total of 39 distinct mutations were found at the seven loci in 114/123 (92.7%) MDR-TB isolates. Frequencies of INH, RIF, OFLX and KAN resistance-associated mutations were 82.1% (101/123), 83.7% (103/123), 92.1% (35/38) and 76.2% (16/21), respectively. The most prevalent mutations involved in resistance were: Ser315Thr in katG (70/123; 56.9%) and C(-15)T in inhA (15/123; 12.2%) for INH; Ser531Leu in rpoB (72/123; 58.5%) for RIF; Asp94Gly in gyrA (10/38; 26.3%) for OFLX; and A1401G in rrs (12/21; 57.1%) for KAN. Four novel gyrB mutants (Leu442Leu, Ser447Phe, Asn499Thr and Ala504Val) were identified. Mutations in katG, rpoB (or both) and the inhA promoter showed a sensitivity of 75.6% and specificity of 97.0% for detection of MDR-TB. DNA sequencing of the seven loci was 57.1% sensitive and 91.0% specific for prediction of XDR-TB isolates. CONCLUSION:These results may be of value in rapid molecular detection of MDR- and XDR-TB isolates in clinical samples in Hebei Province.

Background: Previous studies have revealed that quantitative hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (qAnti-HBc) levels can be used as predictors of treatment response in both interferon-alpha and nucleoside analogue therapies. Few data have been published regarding the relationship between quantitative HBsAg or Anti-HBc levels and liver fibrosis stages in patients with chronic hepatitis B (CHB). Methods: We conducted a cross-sectional study of treatment-na ve CHB patients. A total of 624 CHB patients were recruited. We assessed the serum HBsAg and qAnti-HBc levels, HBV DNA levels, HBV genotypes, BCP/PC mutations, histological fibrosis staging by Scheuer classification. Results: In HBeAg (+) patients, the S0-1 subjects had significantly higher serum HBsAg and lower qAnti-HBc levels than the S2-4 subjects (both p < 0.001). A moderate inverse correlation was present between serum HBsAg levels and fibrosis scores (r = 0.381, p < 0.001), and a moderate positive correlation was found between qAnti-HBc levels and fibrosis scores (r = 0.408, p < 0.001). In the HBeAg (-) patients, the S0-1 subjects also had significantly lower qAnti-HBc levels than the S2-4 subjects (p < 0.001); however, no significant difference in the HBsAg levels was observed between the S0-1 and S2-4 subjects (p > 0.05). Serum qAnti-HBc levels showed a moderate positive correlation with fibrosis scores (r = 0.383, p < 0.001), while serum HBsAg levels exhibited a low inverse correlation with fibrosis scores (r = 0.171,p < 0.001). Multiple logistic regression analysis showed that the parameters for predicting significant fibrosis (S >= 2) included age, PLT, qAnti-HBc levels, HBV genotype and BCP/PC mutations in HBeAg (+) group, and age, PLT, qAnti-HBc levels in HBeAg (-) group (all p < 0.05). The AUC of qAnti-HBc levels associated with the diagnosis of significant fibrosis abnormalities in HBeAg (+) and HBeAg (-) patients were 0.734 (95%CI 0.689 to 0.778) and 0.707 (95%CI 0.612 to 0.801), respectively. Conclusion: Our study found an association between high serum qAnti-HBc levels and significant fibrosis in both HBeAg (+) and HBeAg (-) treatment-naive CHB patients. However, low serum HBsAg levels were correlated with moderate to severe fibrosis in HBeAg (+) subjects only. Copyright (C) 2018, the Chinese Medical Association. Published by Elsevier Taiwan LLC.

Drug-resistant tuberculosis (DR-TB), particularly multidrug-resistant tuberculosis (MDR-TB), has been identified as a major challenge for effective TB control. For rapid detection and proper treatment, molecular assays based on the identification of mutations in genes associated with drug resistance have been established to determine drug resistance. However, there is as yet little information about drug resistance-associated mutations of clinical Mycobacterium tuberculosis isolates from Hebei. In this study, four genetic loci katG, inhA, oxyR-ahpC intergenic region and rpoB were sequenced among 276 DR-TB isolates from Hebei to understand the association between specific mutations, drug resistance phenotypes and spoligotyping genotypes. Altogether, 83.8% of INH resistant isolates harbored at least one mutation of katG, inhA, and oxyR-ahpC intergenic region and 78.4% of RIF resistant isolates harbored one or more mutations in rpoB. The predominant mutation patterns of rpoB and katG in Hebei was Ser531Leu and Ser315Thr, respectively. Additionally, 91.2% of MDR isolates harbored at least one mutation in these four targeted fragments. Compared with the phenotypic data, the sensitivity and specificity of co-testing of katG, inhA promoter and oxyR-ahpC intergenic region for INH resistance were 83.8% and 96.8%, respectively and the rpoB exhibited a sensitivity of 78.4% and a specificity of 95.3% for RIF resistance. Furthermore, there was no association between drug resistance-conferring mutations and spoligotypes. This finding will be useful for the establishment of rapid molecular diagnostic methods in Hebei province, China.

To understand the genetic diversity and phenotypic resistance of Mycobacterium tuberculosis (MTB) strains isolated in Shijiazhuang. Spoligotyping and MIRU-VNTR were performed to genotype MTB isolates and drug susceptibility testing (DST) was used to obtain phenotypic resistance. The genotyping result with drug resistance profiles and clinical characteristics was assessed. A total of 422 strains were collected from Shijiazhuang. The predominant lineage was the Beijing family (91.0%). The VNTR-15standard divided 69 strains into 27 clusters (2-7 strains per cluster) and 353 individual types. The clustering rate was 9.95% and HGDI value reached 0.999. In contrast, the VNTR-15China with a clustering rate of 40.3% and a HGDI score of 0.989, grouped 229 strains into 59 clusters (2-32 strains per cluster) and 193 unique genotypes. MTB drug resistance rate in retreatment patients was statistically higher than that of initial treatment panels. However, no statistical difference of drug resistance rate was observed between the Beijing and the non-Beijing genotypes. The Beijing family is the predominant genotype in Shijiazhuang. Anti-TB drug treatment is associated with MTB drug resistance. VNTR-15standard has a higher discriminatory power than VNTR-15China. Combination of spoligotyping and MIRU-VNTR is suitable for understanding the molecular epidemiology of MTB strains in Shijiazhuang.