Decreased mortality seen in rifampicin/multidrug-resistant tuberculous meningitis treated with linezolid in Shenzhen, China.

BACKGROUND: The morbidity of rifampicin/multidrug-resistant tuberculous meningitis (RR/MDR-TBM) has shown an increasing trend globally. Its mortality rate is significantly higher than that of non-rifampicin/multidrug-resistant tuberculous meningitis (NRR/MDR-TBM). This article aimed to explore risk factors related to RR/MDR-TBM, and compare therapeutic effects of linezolid (LZD)- and non-linezolid-containing regimen for RR/MDR-TB patients in Shenzhen city. Furthermore, we aimed to find a better therapy for pathogen-negative TBM with RR/MDR-TBM related risk factors. METHODS: We conducted a retrospective study enrolling 137 hospitalized cases with confirmed TBM from June 2014 to March 2020. All patients were divided into RR/MDR-TBM group (12 cases) and NRR/MDR-TBM group (125 cases) based on GeneXpert MTB/RIF and (or) phenotypic drug susceptibility test results using cerebral spinal fluid (CSF). The risk factors related to RR/MDR-TBM were investigated through comparing clinical and examination features between the two groups. The mortality rate of RR/MDR-TBM patients treated with different regimens was analyzed to compare their respective therapeutic effects. A difference of P < 0.05 was considered statistically significant. RESULTS: Most patients (111/137, 81%) were from southern or southwestern China, and a large proportion (72/137, 52.55%) belonged to migrant workers. 12 cases were RR/MDR-TBM (12/137, 8.8%) while 125 cases were NRR/MDR-TBM (125/137, 91.2%). The proportion of patients having prior TB treatment history in the RR/MDR-TBM group was significantly higher than that of the NRR/MDR-TBM group (6/12 vs. 12/125, 50% vs. 10.5%, P < 0.01). No significant difference was observed on other clinical and examination features between the two groups. Mortality was significantly lower in RR/MDR-TBM patients on linezolid-containing treatment regimen than those who were not (0/7 versus 3/5, 0% versus 60%, P = 0.045). CONCLUSIONS: The main related risk factor of RR/MDR-TBM is the history of anti-tuberculosis treatment. Linezolid-containing regimen appears to lower mortality rate of RR/MDR-TBM significantly in our study. We think Linezolid should be evaluated prospectively in the treatment of RR/MDR-TBM.

Identification of Mycobacterium abscessus species and subspecies using the Cas12a/sgRNA-based nucleic acid detection platform.

The rapidly growing mycobacterium Mycobacterium abscessus is a clinically important organism causing pulmonary and skin diseases. The M. abscessus complex is comprised of three subspecies: M. abscessus subsp. abscessus, M. abscessus subsp. massiliense, and M. abscessus subsp. bolletii. Here, we aimed to develop a Cas12a/sgRNA-based nucleic acid detection platform to identify M. abscessus species and subspecies. By designing specific sgRNA probes targeting rpoB and erm(41), we demonstrated that M. abscessus could be differentiated from other major mycobacterial species and identified at the subspecies level. Using this platform, a total of 38 clinical M. abscessus isolates were identified, 18 as M. abscessus subsp. abscessus and 20 as M. abscessus subsp. massiliense. We concluded that the Cas12a/sgRNA-based nucleic acid detection platform provides an easy-to-use, quick, and cost-effective approach for identification of M. abscessus species and subspecies.

A retrospective study on intracranial mixed infection with tuberculous meningitis in Shenzhen, China.

Tuberculous meningitis (TBM) is a prevalent global intracranial infection and the most lethal and disabling form of tuberculosis. TBM with mixed intracranial infections is clinically rare but has a higher mortality rate. To investigate the clinical characteristics of TBM with mixed intracranial infections, demographic and clinical data of TBM and pulmonary tuberculosis (PTB) patients admitted to Shenzhen Third People's Hospital between January 2015 and October 2022 were collected anonymously. A total of 207 cases of TBM were diagnosed, of which 16 cases (7.73%) were TBM with mixed intracranial infections. The overall mortality rate of TBM cases was 16.4%, while the mortality rate of TBM cases with mixed intracranial infections was as high as 35.7%. Compared to simple TBM cases, TBM cases with mixed intracranial infections had severer clinical symptoms. The percentage of human immune deficiency virus (HIV)-positive TBM cases with mixed intracranial infections reached up to 68.8%. HIV co-infection, CD4+/CD8+ T-cell counts less than 1, cranial nerve impairment, paralysis, cerebral infarction, PRO less than 450 mg/L, WBC less than 10 × 106 /L, and CL more than 120 mmol/L were risk factors for TBM cases with mixed intracranial infections. Compared to PTB, HIV co-infection, CD4+ T cell less than 550 /uL, and age less than 45 years were risk factors for TBM, and TBM was associated with higher mortality rates. Our study provides additional data to better understand single TBM and TBM with mixed intracranial infections. More than two-thirds of TBM cases with mixed intracranial infections were HIV-positive. Clinicians should consider the possibility of multiple infections in people with TBM/HIV co-infection. IMPORTANCE: TBM can cause severe neurological damage and death, and TBM with mixed intracranial infections can exacerbate the damage and poor prognosis of the disease. TBM with mixed intracranial infections is a rare disease, which has led to an incomplete understanding of its clinical features. This study investigated the clinical features of TBM and its associated factors by comparing the characteristics of TBM with mixed intracranial infections, single TBM and pulmonary tuberculosis. This information will help to improve the understanding of TBM, diagnostic accuracy and treatment outcomes.

Diagnostic Performance of a Novel CXCL10 mRNA Release Assay for Mycobacterium tuberculosis Infection.

One-fourth of the world's population has been infected with Mycobacterium tuberculosis (M.tb). Although interferon-gamma release assays (IGRAs) have been shown to be valid methods for identifying M.tb infection and auxiliary methods for diagnosis of active tuberculosis (TB), lower sensitivity and higher indeterminate rate were often detected among immunosuppressed patients. IP-10 was an alternative biomarker due to the higher expression level after M.tb antigen stimulation, but whether CXCL10 mRNA (the gene that transcribes for the IP-10 protein) can be used as a target for M.tb infection diagnosis was limited. Therefore, we aimed to evaluate the performance of a novel M.tb-specific CXCL10 mRNA release assay in diagnosis of M.tb infection. Suspected TB patients and healthy controls were prospectively recruited between March 2018 and November 2019 from three hospitals in China. CXCL10 mRNA release assay and traditional interferon-gamma release assay (T-SPOT.TB) were simultaneously performed on peripheral blood. Of the 1,479 participants enrolled in the study, 352 patients with definite TB and 153 healthy controls were analyzed. CXCL10 mRNA release assay provided a sensitivity of 93.9% (95% CI = 90.8-96.2%) and a specificity of 98.0% (95% CI = 94.3-99.6%) in the diagnosis of M.tb infection, respectively, while T-SPOT.TB gave a sensitivity of 94.5% (95% CI = 91.5-96.6%) and a specificity of 100% (95% CI = 97.6-100.0%) in the diagnosis of M.tb infection, respectively. The diagnostic performance of CXCL10 mRNA release assay was consistent with T-SPOT.TB, with a total coincidence rate of 95.0% (95% CI = 93.0-96.9%) and a Cohen's kappa value of 0.89 (0.84-0.93, p < 0.001). However, among TB patients with HIV co-infection (n = 14), CXCL10 mRNA release assay presented significantly higher positive rate [92.9% (66.1-99.8%) vs. 61.5% (31.6-86.1%), p = 0.029] than those of T-SPOT.TB. These results suggested that M.tb-specific CXCL10 mRNA was a novel and useful target in the diagnosis of M.tb infection.

[Study on characteristics of cellular-mediated immune responses of novel H1N1 influenza A patients with pneumonia].

OBJECTIVE: To investigate the phenotype, frequency and function of CD4+ T cell subsets and the relevant cytokines, as well as the relationship between these cells and appearance of pneumonia of novel (H1N1) influenza A patients. METHODS: 68 healthy people, 53 confirmed novel A(H1N1) influenza patients without pneumonia and 16 confirmed severe novel A (H1N1) influenza patients with pneumonia were enrolled in this study. Viral load in nasopharyngeal swabs specimens was measured by real time PCR assay. The phenotype and percentage of CD4+ T cell subsets including Th1, Th2, Th17, and Treg cells were measured by Flow cytometry analysis. The relevant cytokines in plasma including TGF-beta, IL-6 and IFN-gamma were measured by ELISA. Data was analyzed by one way ANOVA. RESULTS: It was found that peak viral load and viral shedding period of severe patients with pneumonia was significantly increased compared with mild patients without pneumonia (P < 0.05). The percentage of Th17 cells of severe patients with pneumonia was significantly diminished compared to that of healthy subjects and mild patients without pneumonia (P < 0.05). However, Th1, Th2, Treg cells frequencies had no significant differences (P > 0.05) among these three groups. The level of TGF-beta in plasma for the severe patients with pneumonia was also significantly decreased compared to that of healthy subject and mild patients without pneumonia (P < 0.05). The viral shedding period inversely correlated with the frequency of Th17 cells (r = - 0.38, P < 0.05). CONCLUSION: H1N1 influenza A virus can inhibit Th17 cells to differentiate, particularly more extent in patients with pneumonia. Impaired Th17 cells may correlate with viral clearance and pneumonia of novel H1N1 influenza A patients.