Bibliometric analysis of tuberculosis molecular epidemiology based on CiteSpace.

Background: Tuberculosis is a communicable disease that is a major cause of ill health. Bibliometrics is an important statistical methodology used to analyze articles and other publications in the literature study. In this study, publications on molecular epidemiology were analyzed using bibliometric analysis. The statistical analysis of influential publications, journals, countries and authors was first conducted. Methods: The Web of Science database was searched for publications on the molecular epidemiology of tuberculosis with the keywords "tuberculosis" and "molecular epidemiology" in the title. The number of publications, citation analysis, co-authorship of the author, institution and country, keyword co-occurrence, and reference co-citations were analyzed. Results: A total of 225 journal articles were retrieved. The mean citation was 37.72 per article and 292.69 per year. The annual publications on molecular epidemiology fluctuated within a certain range in the past. Journal of Clinical Microbiology is the most published journal with 33 articles. RASTOGI N is the most prolific author with 11 articles. The top 1 research institution is Inst Pasteur Guadeloupe. Stratified by the number of publications, the USA was the most prolific country. It also cooperates closely with other countries. Burstness analysis of references and keywords showed that the developing research trends in this field mainly focused on "genetic diversity" and "lineage" during the past decade. Conclusion: The annual publications on tuberculosis molecular epidemiology fluctuated within a specific range in the past decade. The USA continues to dominate research output and funding. The exchange of expertise, ideas, and technology is of paramount importance in this field. More frequent and deeper cooperation among countries or institutions will be essential in the future.

Molecular Signatures Related to the Virulence of Bacillus cereus Sensu Lato, a Leading Cause of Devastating Endophthalmitis.

Bacillus endophthalmitis is a devastating eye infection that causes rapid blindness through extracellular tissue-destructive exotoxins. Despite its importance, knowledge of the phylogenetic relationships and population structure of intraocular Bacillus spp. is lacking. In this study, we sequenced the whole genomes of eight Bacillus intraocular pathogens independently isolated from 8/52 patients with posttraumatic Bacillus endophthalmitis infections in the Eye Hospital of Wenzhou Medical University between January 2010 and December 2018. Phylogenetic analysis revealed that the pathogenic intraocular isolates belonged to Bacillus cereus, Bacillus thuringiensis and Bacillus toyonensis To determine the virulence of the ocular isolates, three representative strains were injected into mouse models, and severe endophthalmitis leading to blindness was observed. Through incorporating publicly available genomes for Bacillus spp., we found that the intraocular pathogens could be isolated independently but displayed a similar genetic context. In addition, our data provide genome-wide support for intraocular and gastrointestinal sources of Bacillus spp. belonging to different lineages. Importantly, we identified five molecular signatures of virulence and motility genes associated with intraocular infection, namely, plcA-2, InhA-3, InhA-4, hblA-5, and fliD using pangenome-wide association studies. The characterization of overrepresented genes in the intraocular isolates holds value to predict bacterial evolution and for the design of future intervention strategies in patients with endophthalmitis.IMPORTANCE In this study, we provided a detailed and comprehensive clinicopathological and pathogenic report of Bacillus endophthalmitis over the 8 years of the study period. We first reported the whole-genome sequence of Bacillus spp. causing devastating endophthalmitis and found that Bacillus toyonensis is able to cause endophthalmitis. Finally, we revealed significant endophthalmitis-associated virulence genes involved in hemolysis, immunity inhibition, and pathogenesis. Overall, as more sequencing data sets become available, these data will facilitate comparative research and will reveal the emergence of pathogenic "ocular bacteria."

Activities of Biapenem against Mycobacterium tuberculosis in Macrophages and Mice.

OBJECTIVE: To assess the activities of biapenem against multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis. METHODS: Biapenem/clavulanate (BP/CL) was evaluated for in vitro activity against Mycobacterium tuberculosis (Mtb) multidrug-resistant (MDR) isolates, extensively drug-resistant (XDR) isolates, and the H37RV strain. BP/CL activity against the H37Rv strain was assessed in liquid cultures, in macrophages, and in mice.. RESULTS: BP/CL exhibited activity against MDR and XDR Mtb isolates in liquid cultures. BP/CL treatment significantly reduced the number of colony forming units (CFU) of Mtb within macrophages compared with control untreated infected macrophages. Notably, BP/CL synergized in pairwise combinations with protionamide, aminosalicylate, and capreomycin to achieve a fractional inhibitory concentration for each pairing of 0.375 in vitro. In a mouse tuberculosis infection model, the efficacy of a cocktail of levofloxacin + pyrazinamide + protionamide + aminosalicylate against Mtb increased when the cocktail was combined with BP/CL, achieving efficacy similar to that of the positive control treatment (isoniazid + rifampin + pyrazinamide) after 2 months of treatment. CONCLUSION: BP/CL may provide a new option to clinically treat MDR tuberculosis.

Risk factors and drug resistance in early-onset neonatal group B streptococcal disease.

In recent years, group B streptococcus (GBS) has become an important pathogen that causes infections in many neonatal organs, including the brain, lung, and eye (Ballard et al., 2016). A series of studies performed on GBS infections in western countries have revealed that GBS is one of the primary pathogens implicated in perinatal infection, and GBS infections are a major cause of neonatal morbidity and mortality in the United States (Decheva et al., 2013). In China, GBS is mainly found by screens for adult urogenital tract and perinatal infections, and neonatal GBS infections have been rarely reported. The incidence rate of early-onset neonatal GBS disease is thought to be lower in China than in western countries; however, this data is controversial since it also reflects the clinical interest in GBS (Dabrowska-Szponar and Galinski, 2001).

Genetic signatures of high-altitude adaptation in Tibetans.

Indigenous Tibetan people have lived on the Tibetan Plateau for millennia. There is a long-standing question about the genetic basis of high-altitude adaptation in Tibetans. We conduct a genome-wide study of 7.3 million genotyped and imputed SNPs of 3,008 Tibetans and 7,287 non-Tibetan individuals of Eastern Asian ancestry. Using this large dataset, we detect signals of high-altitude adaptation at nine genomic loci, of which seven are unique. The alleles under natural selection at two of these loci [methylenetetrahydrofolate reductase (MTHFR) and EPAS1] are strongly associated with blood-related phenotypes, such as hemoglobin, homocysteine, and folate in Tibetans. The folate-increasing allele of rs1801133 at the MTHFR locus has an increased frequency in Tibetans more than expected under a drift model, which is probably a consequence of adaptation to high UV radiation. These findings provide important insights into understanding the genomic consequences of high-altitude adaptation in Tibetans.

Identification of novel mutations by targeted exome sequencing and the genotype-phenotype assessment of patients with achromatopsia.

BACKGROUND: Achromatopsia (ACHM) is a severe congenital autosomal recessive retinal disorder caused by loss of cone photoreceptors. Here, we aimed to determine the underlying genetic lesions and phenotypic correlations in two Chinese families with ACHM. METHODS: Medical history and clinical evaluation were obtained from both families. Targeted exome sequencing (TES) was performed on 201 disease-causing genes of inherited retinal dystrophies to screen for ACHM causative mutations in the two probands. RESULTS: The compound heterozygous mutations in CNGA3 (c.1074G > A, p.W358X; c.1706G > A, p.R569H) were identified in the first proband, and a novel homozygous mutation (c.968C > A, p.A323D) was detected in the other pedigree. The proposed topological model of the CNGA3 polypeptide suggested that the missense mutations primarily affected the transmembrane helix 5 and the cGMP-binding domain, respectively. Crystal structure modeling of the cyclic nucleotide-gated cation channel α-3 (CNGA3) protein encoded by the CNGA3 gene revealed an abnormal combined structure generated by R569H. CONCLUSIONS: We firstly used the TES approach to identify genetic alterations in patients with ACHM. We uncovered three mutations in CNGA3, including one novel mutation. Our results not only expand the genotypic spectrum for CNGA3 mutations, but also demonstrate that the TES approach is a valuable tool for molecular diagnosis.

CFI-rs7356506 is a genetic protective factor for acute anterior uveitis in Chinese patients.

BACKGROUND: Complement Factor I (CFI) and the CD46 complement regulator (CD46) play an important role in the complement activation pathways, which is known to affect the development of uveitis. The present study was performed to investigate the association of the CFI and CD46 genes with acute anterior uveitis (AAU). METHODS: A total of 600 subjects (300 patients with AAU and 300 healthy controls) were recruited for this case-control study. Six CFI single nucleotide polymorphisms (SNP) (rs7356506, rs10029485, rs11726949, rs12512308, rs7438961, rs998538) and four CD46 SNPs (rs12138764, rs2466571, rs2796278, rs7545126) were genotyped using Sequenom MassARRAY technology. Allele and genotype frequencies were compared between patients and controls using the χ(2) test. Analyses were stratified for gender, human leukocyte antigen (HLA)-B27, and ankylosing spondylitis status. RESULTS: Rs7356506 in the CFI gene was found to be protective against AAU. There was a significant increase in the frequency of the A allele (p=0.003, pc=0.03, OR=0.684, CI 0.534 to 0.876) and AA homozygosity (p=0.004, pc=0.04, OR=0.624, CI 0.452 to 0.862) in AAU patients as compared to controls. Stratified analysis, according to gender and HLA-B27 status for AAU, also revealed the association with CFI-rs7356506. None of the tested SNPs of CD46 were associated with AAU. CONCLUSIONS: This study has revealed a significant association between AAU and CFI-rs7356506, suggesting that CFI is involved in the pathogenesis of AAU, and that its influence on AAU may differ depending on gender and HLA-B27 status.

Clinical analysis of 240 patients with HLA-B27 associated acute anterior uveitis.

PURPOSE: To analyze the prevalence of HLA-B27 associated acute anterior uveitis and to identify its clinical features. METHODS: A total of 240 patients with HLA-B27 associated acute anterior uveitis, who were admitted to Zhejiang Ophthalmologic Hospital between December 2006 and October 2012, were retrospectively analyzed. The age of onset, sex, affected eyes, HLA-B27 antigen detection, recurrence, joint involvement, and surgical complications were investigated. RESULTS: The average age of onset was 37.0±12.0 years and the ratio of male to female patients was 2.4:1. Most cases had alternate unilateral or bilateral involvement. Among all participants, 234 cases (97.5%) were HLA-B27 positive, and 124 cases (51.7%) had spondyloarthropathies (SpA), dominated by 108 cases with ankylosing spondylitis (AS,45.0%), and mostly seen in male subjects (P<0.05). Six patients were HLA-B27 negative (2.5%) and no statistical significance was noted between male and female patients (P>0.05). A total of 193 cases (80.4%) presented with complications, mainly fibrinous exudation, posterior synechia, and vitreous opacity. CONCLUSION: HLA-B27 that is associated acute anterior uveitis with a relatively high incidence and recurrence presents with more severe clinical features than does idiopathic acute anterior uveitis, and it often accompanies systemic arthritic diseases. HLA-B27 antibody detection is associated with the diagnosis and treatment of acute anterior uveitis.

Synthesis and anti-tubercular activity of novel alkyl substituted riminophenazine derivatives.

A series of novel riminophenazine derivatives bearing an alkyl substituent attached to N-5 and imino nitrogen at C-3 position of the phenazine ring were obtained through rational drug design, aiming to maintain high anti-tubercular activity, lower toxicity and reduce lipophilicity. All target compounds were prepared by utilizing simple and flexible synthetic route and evaluated against Mycobacterium tuberculosis H37Rv and screened for mammalian cytotoxicity. The results demonstrated that compounds with a cyclopropyl substituent at N-5 position were more active than the reference compound clofazimine. In particular, 2-(4-chloroanilino)-5-cyclopropyl-3-(4-methoxycyclohexyl) imino-3, 5-dihydrophenazine (25) was found to be the most potent compound with low cytotoxicity and lipophilicity. This compound could serve as a valuable lead molecule for further optimization.

[A preliminary study on immune adjunctive therapy for multidrug-resistant Mycobacterium tuberculosis infection in animal models].

OBJECTIVE: To investigate the effect of adjunctive therapy by immune agents in mice infected with multidrug-resistant tuberculosis (MDR-TB). METHODS: Sixty-eight adult male BALB/c mice were infected with multidrug-resistant Mycobacterium tuberculosis (MTB) by aerosol route. The mice were randomly divided into a control group, an immuno-treatment group, a drug treatment group and a combination treatment group (drug plus immuno-treatment). In each treatment group, 16 mice were treated at day 21 after infection, and another 4 mice were sacrificed at day 21 after infection (treatment for 0 week) as the blank control group. In the treatment group, 4 mice were sacrificed in turn at the day after treatment for 4, 8, 16 and 20 weeks. Lung and spleen mass index at the day after treatment for 8, 16 and 20 weeks, lung and spleen live bacterial count in each period, serum IFN-γ and IL-10 levels at the day after treatment for 8 weeks were measured. Comparisons of analyzed parameters among groups were performed with the one way ANOVA test, and comparisons of parameters between 2 groups were performed with SNK and Games-Howell test. RESULTS: The lung mass index in the immuno-treatment group (0.66 ± 0.09)%, drug group (0.60 ± 0.07)% and combination therapy group (0.57 ± 0.05)% at the day after treatment for 8 weeks were significantly lower than that of the control group (0.81 ± 0.09)%, (F = 7.364, P < 0.01). Spleen CFU of immuno-treatment group at 16 and 20 weeks [(3.11 ± 0.14) lg CFU and (3.15 ± 0.18) lg CFU] were significantly lower than those of the control group [(3.77 ± 0.35) lg CFU and (4.31 ± 0.06)] (F values were 446.424 and 2107.689, P < 0.01). Spleen tissues of the drug group and the combination therapy group were sterile from 4 weeks. The serum IFN-γ levels of immuno-treatment group, drug group and combination therapy were (5.3 ± 1.9) ng/L, (1.3 ± 0.5) ng/L and (0.9 ± 1.3) ng/L, respectively, being significantly lower than that of the control group (10.3 ± 2.1) ng/L (F = 32.128, P < 0.01). The lung and spleen mass index, lung and spleen CFU, serum IFN-γ and IL-10 between medication group and combination therapy showed no significant differences. CONCLUSIONS: Immuno-treatment could mitigate lung tissue inflammation, reduce the number of MTB in mouse spleen tissues and decrease serum IFN-γ levels in the MDR-TB mouse model. However immuno-treatment failed to reduce the number of MTB in lung tissues. There was no adjunctive effect of immuno treatment for MDR-TB mice in reducing the number of MTB and mitigating inflammation.

[A study on the activity of clofazimine with antituberculous drugs against Mycobacterium tuberculosis].

OBJECTIVE: To explore the role of clofazimine in combination with other antituberculous drugs against Mycobacterium tuberculosis. METHODS: The minimal inhibitory concentration (MIC) of each drug and the drugs in combination against M. tuberculosis H37Rv were determined, and the synergetic activities according to the fractional inhibitory concentration (FIC) formula was calculated. Female BALB/C mice were infected intravenously with 0.2 mg/L portions containing 5 × 105 CFU of the MDR clinical isolate 2931. One day after the infection, 6 mice were sacrificed and the numbers of CFU in the lungs and spleens were determined. The remaining mice were allocated either to untreated group or to drug-treated groups (6 mice per group). Thirty days post-infection, both untreated and treated mice were sacrificed and the CFU counted. RESULTS: Clofazimine in combination with the 10 antituberculosis drugs resulted in two- to eight fold reduction in MIC. The FIC of clofazimine (Cfz) in combination with p-aminosalicylic acid (PAS), protionamide (Pto), clarithromycin (Clr), and capreomycin were less than 0.5, suggesting a synergic interaction against M. tuberculosis H37Rv. All the drug treatments reduced the numbers of CFU in the lungs and spleens compared with the numbers in the untreated controls. Of the individual drugs, Cfz was the most effective on day 30, with a mean CFU count decrease of 1.82 and 2.32 lg10, in comparison with that of the untreated control. The Cfz-Clr (clarithromycin) combination showed significantly greater activity than the control or Clr alone, with a mean CFU count decrease of 1.30 and 1.91 lg, in comparison with that of the Clr treatment. Cfz-Clr was slightly more active than Cfz alone, but not at a statistically significant level. CONCLUSIONS: The activity of clofazimine was enhanced by the addition of clarithromycin. These observations are important for the therapy of multidrug-resistant tuberculosis.

[Tissue distribution and deposition of clofazimine in mice following oral administration of isoniazid].

OBJECTIVE: Tissue distribution and deposition of clofazimine in mice were investigated following administration of clofazimine with or without isoniazid. METHODS: Kunming mice were given clofazimine suspension orally at a daily dose of 13 mg/kg body weight either alone or with isoniazid (25 mg/kg body weight) for a single dose or for 1 or 2 months. Tissues (liver, lung, spleen, small intestine, kidneys, fat) and pooled plasma were analyzed for clofazimine in all the treated groups by high-performance liquid chromatography. RESULTS: The levels of clofazimine in fat tissues, kidneys, spleens, livers, lungs and small intestine were the highest in mice receiving the drug continuously for 2 months, and were also higher in mice receiving the drug for 1 month as compared to mice receiving a single dose administration. After continuous administration for 1 or 2 months, the clofazimine level was the highest in fat tissues as compared to other tissue samples. The clofazimine level in the lungs was higher in mice receiving concomitant administration of isoniazid [1 month (57 +/- 11) microg/g, 2 months (73 +/- 49) microg/g]than in those receiving clofazimine alone [1 month (32 +/- 8) microg/g, 2 months (47 +/- 12) microg/g], but the clofazimine level in the fat tissue was significantly lower in mice receiving concomitant isoniazid [1 month (289 +/- 30) microg/g, 2 months (275 +/- 119) microg/g], than in those receiving clofazimine alone [1 month (433 +/- 53) microg/g, 2 months (527 +/- 158) microg/g]. CONCLUSION: Concomitant administration of isoniazid reduced clofazimine levels significantly in fat tissues while resulted in an increase of its level in lung tissues.

[Activities of clofazimine against Mycobacterium tuberculosis in vitro and in vivo].

OBJECTIVE: To evaluate the in vitro and in vivo antituberculous activities of clofazimine. METHODS: The MIC of clofazimine against H(37)Rv and 30 MDR-TB clinical strains were determined by microplate Alamar blue assays. Female BALB/c mice were infected with M. tuberculosis H(37)Rv (10(5) CFU/mouse). The infected mice were divided into the following groups: a control group, treated with saline 5 times per week; isoniazid treatment group, 25 mg/kg, 5 times per week; clofazimine 20 mg/kg group, 5 times per week; clofazimine 10 mg/kg group, 5 times per week, and another clofazimine 20 mg/kg group, but the drug was given twice weekly. The drugs and saline were administered by gavage, and the treatment lasted for 30 days after infection. Five mice from each group were assessed for bacterial CFU count and organ weights of the lung and spleen on day 30. RESULTS: The MIC of clofazimine against M. tuberculosis H(37)Rv was 0.12 - 0.24 microg/ml, and the MIC against 30 MDR-TB clinical strains ranged from 0.12 to 1.92 microg/ml. In the murine model, clofazimine treatments decreased the CFU by 1.39 - 2.92 lg as compared to that of the control group on day 30. CONCLUSIONS: Clofazimine has in vitro and in vivo activities against M. tuberculosis.

[Analysis of single nucleotide polymorphism in the human beta-globin gene of patients with minor beta-thalassemia from Wenzhou].

This study was aimed to analyze the hematologic and molecular biologic characteristics of 14 Wenzhou patients with minor beta-thalassemia, to find out the mutation sites responsible for the disease by detecting sequences of PCR products and to analyze the single nucleotide polymorphism. The peripheral blood of patients was collected intravenously and was anticoagulated with EDTA-K(2); then the templates from blood samples were extracted, the related primers were designed for sequencing the products amplified by PCR; finally mutation sites resulting in beta-thalassemia were found through comparison and analysis of sequences. The results indicated that the C-->T heterozygous mutation occurred at the IVS-2 -654 site in 4 cases; the TTCT deficiency appeared at CD41/42 site in 1 case; in 2 sites existed single nucleotide polymorphisms occurring at the 59th site of exon 1 (T/C, CAT/CAC, His) and IVS-2 nt 665 (T/C). It is concluded that single nucleotide polymorphism of minor beta-thalassemia patients born in Wenzhou had specificity, this study found too kinds of gene mutations which are IVS-2 -654 C-->T heterozygous mutation and CD41/CD42 site-TTCT deficiency.