Significance of LncRNA CASC8 genetic polymorphisms on the tuberculosis susceptibility in Chinese population.

BACKGROUND: Tuberculosis remains an important disease threatening the security of public health, and no effective targets have been found for the immunological diagnosis or therapy of tuberculosis. The aim of this study was to explore the associations between lncRNA CASC8 genetic polymorphism and tuberculosis risk. METHOD: A total of 900 tuberculosis patients and 1534 healthy individuals in the Western Chinese Han population were recruited for our study. Candidate SNPs of CASC8 were initially filtered by importing the 1000 genomes database into Haploview, and subsequently genotyped using modified multiplex ligation detection reactions. RESULTS: The lncRNA CASC8 genetic variant rs7836840 was associated with an increased tuberculosis risk with a P-value of .034, but .134 after Bonferroni correction. Using subtype analysis, the C allele in rs7836840 showed a significant association with tuberculosis susceptibility (OR = 1.196, 95% CI = 1.05-1.362, P = .02739 after Bonferroni correction). Patients carrying genotype AG and GG of rs7825118 and rs9297758 exhibited lower Hb concentrations (P = .006) and neutrophil counts (P = .015), respectively, while genotype AG and AA in rs6981424 demonstrated higher levels of ALT (P = .005) and AST (P = .033) in a dominant model, which were consistent with a tendency toward increased TB risk. CONCLUSIONS: This study was the first to explore the association between lncRNA CASC8 polymorphisms and TB infection risk and clinical manifestations. Our results provide evidence that CASC8 may act as a biomarker for the progression of clinical tuberculosis.

Emergence of mcr-1-Harboring Salmonella enterica Serovar Sinstorf Type ST155 Isolated From Patients With Diarrhea in Jiangsu, China.

Background: This study analyzed the antimicrobial resistance phenotypes and mechanisms of quinolone, cephalosporins, and colistin resistance in nontyphoidal Salmonella from patients with diarrhea in Jiangsu, China. Methods: A total of 741 nontyphoidal Salmonella isolates were collected from hospitals in major cities of Jiangsu Province, China between 2016 and 2017. Their susceptibility to commonly used antibiotics was evaluated by broth micro-dilution and sequencing analysis of resistance genes screened by a PCR method. For mcr-1 positive isolates, genetic relationship study was carried out by pulsed-field gel electrophoresis and multiloci sequence typing analysis. The transferability of these plasmids was measured with conjugation experiments and the genetic locations of mcr-1 were analyzed by pulsed-field gel electrophoresis profiles of S1-digested genomic DNA and subsequent Southern blot hybridization. Results: Among 741 nontyphoidal Salmonella isolates, the most common serotypes identified were S. Typhimurium (n=257, 34.7%) and S. Enteritidis (n=127, 17.1%), and the isolates showed 21.7, 20.6, and 5.0% resistance to cephalosporins, ciprofloxacin, and colistin, respectively. Among the 335 nalidixic acid-resistant Salmonella, 213 (63.6%) and 45 (13.4%) had at least one mutation in gyrA and parC. Among the plasmid-borne resistance, qnrS1 (85; 41.9%) and aac(6')-Ib-cr4 (75; 36.9%) were the most common quinolone resistance (PMQR) genes, while bla CTX-M-14 (n=35) and bla CTX-M-55 (n=46) were found to be dominant extended-spectrum beta-lactamase (ESBL) genes in nontyphoidal Salmonella. In addition, eight mcr-1-harboring strains were detected since 2016 and they were predominate in children under the age of 7years. Conjugation assays showed the donor Salmonella strain has functional and transferable colistin resistance and Southern blot hybridization revealed that mcr-1 was located in a high molecular weight plasmid. Conclusion: In nontyphoidal Salmonella, there is a rapidly increasing trend of colistin resistance and this is the first report of patients harboring mcr-1-positive Salmonella with a new ST type ST155 and new serotype S. Sinstorf. These findings demonstrate the necessity for cautious use and the continuous monitoring of colistin in clinical applications.

Up-regulated long noncoding RNA AC007128.1 and its genetic polymorphisms associated with Tuberculosis susceptibility.

BACKGROUND: Tuberculosis (TB) remains a major public health problem. Long non-coding RNAs (lncRNAs) are important regulators of gene expression. In this study, we explored the association between the expression of lncRNA AC007128.1 and TB susceptibility. METHODS: Three single-nucleotide polymorphisms (SNPs) (rs12333784, rs6463794, and rs720964) of lncRNA AC007128.1 were selected using the 1000 Genomes Project database and offline software Haploview V4.2, and were genotyped by a customized 2×48-Plex SNPscan™ Kit. RESULTS: We identified two differentially expressed lncRNA including AC007128.1 and AP001065.3 in comparisons of expression profiles between ATB vs. LTBI, LTBI vs. HCs, and AC700128.1 expression was specifically and significantly up-regulated in TB patients by verification of external data. Gene Ontology functional enrichment analysis and co-expression network showed up-regulated mRNA was mainly involved in negative regulation of the G protein-coupled receptor (GPCR) signaling pathway, and FPR1 and CYP27B1 were involved in the co-expression of AC007128.1. Using the 1000 Genomes Project, software Haploview V4.2, and SNP genotype, we screened out SNP rs12333784 which locus at 7p21.3 in AC007128.1 associated with TB susceptibility. The G carrier of rs12333784 was then finally verified to be significantly associated with pulmonary TB (PTB) and extrapulmonary tuberculosis (EPTB) susceptibility (pBonferroni =0.03878), and a similar but more significant effect was observed under the dominant model analysis (pBonferroni =0.013, OR =1.349, 95% CI, 1.065-1.709). In addition, the GG + GA genotype of SNP rs12333784 was significantly correlated with higher glucose (GLU) (P=0.03), higher gamma-glutamyl transferase (GGT) (P=0.05), and higher erythrocyte sedimentation rate (ESR) (P=0.05). CONCLUSIONS: Our findings show lncRNA AC007128.1 can be regarded as biomarkers discriminating between ATB and LTBI and may also be a diagnostic biomarker for LBTI. These findings may aid clinical decision making in the management of TB.

Discovery of seven novel mutations of gyrB, parC and parE in Salmonella Typhi and Paratyphi strains from Jiangsu Province of China.

OBJECTIVE: To investigate the prevalence of Salmonella Typhi and Paratyphi resistance to quinolones and characterize the underlying mechanism in Jiangsu Province of China. METHODS: Antimicrobial susceptibility testing was performed using Kirby-Bauer disc diffusion system. Quinolone resistance-determining region (QRDR), plasmid-mediated quinolone resistance (PMQR) determinant genes were detected by PCR and sequencing. RESULTS: Out of 239 Salmonella isolates, 164 were S. Typhi and 75 were S. Paratyphi. 128 (53.6%) Salmonella isolates were resistant to nalidixic acid; 11 (4.6%) isolates to ciprofloxacin and 66 (27.6%) isolates were intermediate to ciprofloxacin. QRDR were present in 69 S. Typhi isolates, among which mutation at codon 83 (n = 45) and 133 (n = 61) predominated. In S. Paratyphi, the most common mutations were detected in gyrA at codon 83(n = 24) and parC: T57S (n = 8). Seven mutations were first reported in Salmonella isolates including gyrB: S426G, parC: D79G and parE: [S498T, E543K, V560G, I444S, Y434S]. PMQR genes including qnrD1, qnrA1, qnrB4, aac (6')-Ib-cr4 and qnrS1 were detected in 1, 2, 3, 7 and 9 isolates, relatively. CONCLUSIONS: High resistance to quinolones in Salmonella remains a serious problem in Jiangsu, China. The presence of the novel mutations increases the complexity of quinolone-resistant genotypes and poses a threat to public health. Subject terms: Salmonella Typhi, Salmonella Paratyphi, antimicrobial resistance, QRDR, PMQR.

Increasing clinical resistance rate of Shigella sonnei to cefotaxime in Jiangsu Province, China, between 2012 and 2015.

BACKGROUND: The objective of this study is to evaluate the prevalence of Shigella sonnei (S. sonnei) and characterize the mechanism of its increasing resistance to cefotaxime, a third-generation cephalosporin agent between 2012 and 2015. METHODS: We investigated the drug resistance in 95 isolates of S. sonnei by K-B dilution method and isolates with the extended-spectrum beta-lactamases (ESBLs)-producing genes were detected by polymerase chain reaction (PCR) and sequencing. RESULTS: Over a 4-year period, the resistance rate of S. sonnei to cefotaxime increased from 31.6% to 64.3%, between 2012 and 2015. Molecular characterization of the ESBL genes, comprising 28 strains of CTX-M-1 group: blaCTX-M-55 (n=22), blaCTX-M-3 (n=3) and blaCTX-M-15 (n=3); 11 strains of CTX-M-9 group: blaCTX-M-14 (n=9) and blaCTX-M-65 (n=2), and 36 strains with blaTEM-1 gene. None of S. sonnei isolates carried blaCTX-M-2 group and SHV-type. CONCLUSIONS: The antimicrobial resistance rate of S. sonnei to cefotaxime significantly increased. Accordingly, regular surveillance of the cephalosporin-resistant S. sonnei should be emphasized. Moreover, exploration of the mechanism underlying the resistance of S. sonnei to cefotaxime contributes to the prophylaxis of further emergence of drug resistance.

Prevalence and characterisation of third-generation cephalosporin-resistant Shigella flexneri isolates from Jiangsu Province, China, 2013-2015.

OBJECTIVES: The aim of this study was to assess the prevalence of Shigella flexneri resistance to third-generation cephalosporins (3GCs) and to characterise the underlying resistance mechanisms. METHODS: A total of 282 S. flexneri strains isolated in 2013-2015 in Jiangsu Province, China, were identified, serotyped and analysed for their susceptibility to 3GCs. The blaTEM, blaSHV, blaOXA-1-like and blaCTX-M-type extended-spectrum ß-lactamase (ESBL) genes were amplified and sequenced by PCR. RESULTS: Of the 282 S. flexneri strains, 97 (34.4%) were resistant to cefotaxime, from which 68 (24.1%) were also resistant to ceftazidime. ESBL genes were detected in 73/97 isolates (75.3%), of which 66/73 (90.4%) showed resistance to 3GCs. Of the 73 ESBL-positive isolates, 32 (43.8%) were positive for CTX-M-1 group (17 for CTX-M-55, 4 for CTX-M-3, 1 for CTX-M-15, 3 for CTX-M-79 and 7 for CTX-M-123), 31 (42.5%) were positive for CTX-M-9 group (29 for CTX-M-14, 1 for CTX-M-24 and 1 for CTX-M-27), 25 (34.2%) were positive for TEM-types (21 for TEM-1 and 4 for TEM-1b) and 1 (1.4%) was positive for SHV-type (SHV-12); none were positive for CTX-M-2 group, CTX-M-8 group and OXA-type. CONCLUSION: ESBLs play an important role in Shigella resistance to 3GCs. CTX-M-14 and CTX-M-55 appeared to be the dominant ESBLs in 13 cities of Jiangsu Province. Therefore, it is time to regularly monitor resistance of S. flexneri to 3GCs and to take appropriate measures to manage this problem.