Clinical Performance of the Xpert® CT/NG Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae: A Multicenter Evaluation in Chinese Urban Hospitals.

Background: We aimed to evaluate the clinical performance of the GeneXpert® (Xpert) CT/NG assay for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) using urine and cervical swabs collected from patients in China. Methods: This study was conducted from September 2016 to September 2018 in three Chinese urban hospitals. The results from the Xpert CT/NG test were compared to those from the Roche cobas® 4800 CT/NG test. Discordant results were confirmed by DNA sequence analysis. Results: In this study, 619 first void urine (FVU) specimens and 1,042 cervical swab specimens were included in the final dataset. There were no statistical differences between the results of the two tests for the detection of CT/NG in urine samples (p > 0.05), while a statistical difference was found in cervical swabs (p < 0.05). For CT detection, the sensitivity and specificity of the Xpert test were 100.0% (95%CI = 96.8-99.9) and 98.3% (95%CI = 96.6-99.2) for urine samples and 99.4% (95%CI = 96.5-100.0) and 98.6% (95%CI 97.5-99.2) for cervical swabs, respectively. For NG detection, the sensitivity and specificity of the Xpert test were 99.2% (95%CI = 94.9-100.0) and 100.0% (95%CI = 99.0-100.0) for urine and 100% (95%CI = 92.8-100.0) and 99.7% (95%CI = 99.0-99.9) for cervical swabs, respectively. Conclusion: The Xpert CT/NG test exhibited high sensitivity and specificity in the detection of CT and NG in both urine and cervical samples when compared to the reference results. The 90-min turnaround time for CT and NG detection at the point of care using Xpert may enable patients to receive treatment promptly.

Increasing Resistance to Azithromycin in Neisseria gonorrhoeae in Eastern Chinese Cities: Resistance Mechanisms and Genetic Diversity among Isolates from Nanjing.

Azithromycin resistance (AZM-R) of Neisseria gonorrhoeae is emerging as a clinical and public health challenge. We determined molecular characteristics of recent AZM-R Nanjing gonococcal isolates and tracked the emergence of AZM-R isolates in eastern Chinese cities in recent years. A total of 384 N. gonorrhoeae isolates from Nanjing collected from 2013 to 2014 were tested for susceptibility to AZM and six additional antibiotics; all AZM-R strains were characterized genetically for resistance determinants by sequencing and were genotyped using N. gonorrhoeae multiantigen sequence typing (NG-MAST). Among the 384 isolates, 124 (32.3%) were AZM-R. High-level resistance (MIC, ≥256 mg/liter) was present in 10.4% (40/384) of isolates, all of which possessed the A2143G mutation in all four 23S rRNA alleles. Low- to mid-level resistance (MIC, 1 to 64 mg/liter) was present in 21.9% (84/384) of isolates, 59.5% of which possessed the C2599T mutation in all four 23S rRNA alleles. The 124 AZM-R isolates were distributed in 71 different NG-MAST sequence types (STs). ST1866 was the most prevalent type in high-level AZM-R (HL-AZM-R) isolates (45% [18/40]). This study, together with previous reports, revealed that the prevalence of AZM-R in N. gonorrhoeae isolates in certain eastern Chinese cities has risen >4-fold (7% to 32%) from 2008 to 2014. The principal mechanisms of AZM resistance in recent Nanjing isolates were A2143G mutations (high-level resistance) and C2599T mutations (low- to mid-level resistance) in the 23S rRNA alleles. Characterization of NG-MAST STs and phylogenetic analysis indicated the genetic diversity of N. gonorrhoeae in Nanjing; however, ST1866 was the dominant genotype associated with HL-AZM-R isolates.

[Mycoplasma genitalium infection in patients attending the STD clinic in Nanjing].

OBJECTIVE: To analyze Mycoplasma genitalium (MG) infection among the patients attending the clinic of sexually transmitted diseases (STD) in Nanjing. METHODS: Urethral and cervical swabs were collected from 2 753 patients (2 161 males and 592 females) who first sought medical care at our STD Clinic from November 2015 to December 2017. The patients ranged in age from 18 to 67 years (ï¼»37.55 ± 10.37ï¼½ yr), divided into six age groups: ≤20, 21－30, 31－40, 41－50, 51－60, and >60 yr. The samples were examined for MG infection by simultaneous amplification and testing, Chlamydia trachomatis (CT) by quantitative real-time PCR, Neisseria gonorrhoeae (NG), Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) with the Thayer-Martin medium, and the count of polymorphonuclear leukocytes (PMNL) by microscopy with Methylene blue stain. RESULTS: Among the 2 753 samples, 219 (7.95%), including 176 males (8.14%) and 43 females (7.26%), were found positive for MG, with no statistically significant differences between the male and female groups (χ2 = 0.492, P = 0.483). The MG infection rates in the male and female groups were 6.67% vs 12.12% in the ≤20-year-olds, 8.44% vs 8.64% in the 21－30-year-olds, 7.63% vs 6.19% in the 31－40-year-olds, 10% vs 4.72% in the 41－50-year-olds, 5.64% vs 0 in the 51－60-year-olds, and 8.33% vs 0 in the >60-year-olds, with no statistically significant differences among the age groups (χ2 = 4.76, P = 0.446), or in the males (χ2 = 7.240, P = 0.200) or females (χ2 = 6.718, P = 0.076). The incidence rate of MG simple infection was markedly higher in the males than in the females (62.30% ï¼»76/122ï¼½ vs 36.84% ï¼»14/38ï¼½, χ2 = 7.041, P < 0.01). MG infection was found in combination with one or more pathogens like NG, CT, UU and MH, with MG+UU as the most common co-infection (21.31% ï¼»26/122ï¼½ in males and 31.85% ï¼»12/38ï¼½ in females). Of the 76 male patients with MG simple infection, 30 (39.47%) had ≥5 PMNLs per high-power field, and 66 (86.84%) showed symptoms of urethritis. CONCLUSIONS: MG infection was found in both the symptomatic and asymptomatic patients attending the STD clinic in Nanjing, with no significant difference in the incidence rate between males and females. A higher rate of MG simple infection was observed in the males than in the females, most of the male patients with symptoms of urethritis and urethral PMNLs.

Antimicrobial susceptibility of Neisseria gonorrhoeae isolates from Hefei (2014-2015): genetic characteristics of antimicrobial resistance.

BACKGROUND: Antimicrobial resistance (AMR) and genetic determinants of resistance of N. gonorrhoeae isolates from Hefei, China, were characterized adding a breadth of information to the molecular epidemiology of gonococcal resistance in China. METHODS: 126 N. gonorrhoeae isolates from a hospital clinic in Hefei, were collected between January, 2014, and November, 2015. The minimum inhibitory concentration (MIC) of N. gonorrhoeae isolates for seven antimicrobials were determined by the agar dilution method. Isolates were tested for mutations in penA and mtrR genes and 23S rRNA, and also genotyped using N. gonorrhoeae multi-antigen sequence typing (NG-MAST). RESULTS: All N. gonorrhoeae isolates were resistant to ciprofloxacin; 81.7% (103/126) to tetracycline and 73.8% (93/126) to penicillin. 39.7% (50/126) of isolates were penicillinase producing N. gonorrhoeae (PPNG), 31.7% (40/126) were tetracycline resistant N. gonorrhoeae (TRNG) and 28.6% (36/126) were resistant to azithromycin. While not fully resistant to extended spectrum cephalosporins (ESCs), a total of 14 isolates (11.1%) displayed decreased susceptibility to ceftriaxone (MIC ≥ 0.125 mg/L, n = 10), cefixime (MIC ≥ 0. 25 mg/L, n = 1) or to both ESCs (n = 3). penA mosaic alleles XXXV were found in all isolates that harbored decreased susceptibility to cefixime, except for one. Four mutations were found in mtrR genes and mutations A2143G and C2599T were identified in 23S rRNA. No isolates were resistant to spectinomycin. Gonococcal isolates were distributed into diverse NG-MAST sequence types (STs); 86 separate STs were identified. CONCLUSIONS: N. gonorrhoeae isolates from Hefei during 2014-2015, displayed high levels of resistance to antimicrobials that had been recommended previously for treatment of gonorrhea, e.g., penicillin, tetracycline and ciprofloxacin. The prevalence of resistance to azithromycin was also high (28.6%). No isolates were found to be fully resistant to spectinomycin, ceftriaxone or cefixime; however, 11.1% isolates, overall, had decreased susceptibility to ESCs.

Meta-analysis of the efficacy of moxifloxacin in treating Mycoplasma genitalium infection.

Mycoplasma genitalium is an important pathogen that is transmitted through sexual contact. For patients diagnosed with M. genitalium infection, the current guidelines recommend 1 g of azithromycin as the first-line treatment. Moxifloxacin is used as a second-line drug due to its remarkable efficacy; however, increased use of moxifloxacin to treat M. genitalium infections has caused the emergence of cases of moxifloxacin treatment failure. This meta-analysis aims to estimate the treatment efficacy of moxifloxacin for M. genitalium infection. Electronic databases were searched for articles published from 1983 to the end of May 2016 using the following search terms: ( Mycoplasma genitalium) AND (moxifloxacin OR 1-cyclopropyl-7-(2,8-diazabicyclo(4.3.0)non-8-yl)-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3-quinoline carboxylic acid OR Proflox OR moxifloxacin hydrochloride OR Octegra OR Avelox OR Avalox OR Izilox OR Actira OR [treatment efficacy]). All included studies were published in English; all participants were diagnosed with M. genitalium infection, and microbial cure times were measured within 12 months after treatment. Treatment efficacy was measured as microbial cure at the final follow-up after treatment. In total, 17 studies including 252 participants met the inclusion criteria. The majority of these studies were observational. The random-effects pooled microbial cure rate was 96% (95% confidence interval [CI], 90%-99%; I2 = 28.59%, P = 0.13). For studies with sample collection deadlines prior to 2010, the pooled microbial cure rate was 100% (95% CI, 99%-100%; I2 = 0.00%, P = 1.00). For studies with sample collection deadlines of 2010 and later, the pooled microbial cure rate was 89% (95% CI, 82%-94%; I2 = 0.00%, P = 0.59). The elimination rate of moxifloxacin for M. genitalium infection has decreased from 100% to 89% since 2010. This decline merits considerable attention. We suggest close follow-up to investigate the efficacy of moxifloxacin for treating M. genitalium infections. Additionally, sentinel points should be established to detect mutations in the gyrA/B and parC/E genes, which are associated with moxifloxacin resistance.

[Gene expression profiling of peripheral blood mononuclear cells in patients with secondary syphilis].

OBJECTIVE: To analyze the gene expression profiling characteristics of peripheral blood mononuclear cells (PBMCs) from patients with secondary syphilis, and gain an insight into the host molecular immune mechanisms involved in Treponema pallidum infection. METHODS: Using genome-based high-throughput Illumina sequencing technology, we comprehensively determined the transcriptional difference in PBMCs from 4 secondary syphilis patients and 4 healthy controls, followed by real time PCR to validate the results of Illumina sequencing. RESULTS: Totally, 78 differentially expressed genes were found in the PBMCs of the secondary syphilis patients, among which 16 were associated with the immune system. Significant upregulation was observed in the expressions of pro-inflammatory cytokines and related receptors, such as TNF receptor super-family member 17 (TNFRSF17), IL-17C, IL-21, IL-31 receptor A (IL-31RA), chemokine C-X-C motif ligand 10 (CXCL10), and chemokine (C-C motif) ligand 1 (CCL1), as well as the transcripts for the CD4+ T lymphocytes activation markers CD38, Fc-mediated phagocytosis receptors (FcγR1A, FcγR3B), and complement (C2, SERPING1). CONCLUSIONS: Systemic innate and adaptive immune effecter molecules are involved in the host clearance mechanism of secondary syphilis.

Multidrug-Resistant Neisseria gonorrhoeae Isolates from Nanjing, China, Are Sensitive to Killing by a Novel DNA Gyrase Inhibitor, ETX0914 (AZD0914).

We tested the activity of ETX0914 against 187 Neisseria gonorrhoeae isolates from men with urethritis in Nanjing, China, in 2013. The MIC50, MIC90, and MIC range for ETX0914 were 0.03 µg/ml, 0.06 µg/ml, and ≤0.002 to 0.125 µg/ml, respectively. All isolates were resistant to ciprofloxacin, and 36.9% (69/187) were resistant to azithromycin. Of the isolates, 46.5% were penicillinase-producing N. gonorrhoeae (PPNG), 36% were tetracycline-resistant N. gonorrhoeae (TRNG), and 13% (24 isolates) had an MIC of 0.125 µg/ml for ceftriaxone. ETX0914 may be an effective treatment option for gonorrhea.

Antimicrobial susceptibility of Neisseria gonorrhoeae isolates from symptomatic men attending the Nanjing sexually transmitted diseases clinic (2011-2012): genetic characteristics of isolates with reduced sensitivity to ceftriaxone.

BACKGROUND: Evolving gonococcal antimicrobial resistance (AMR) poses a serious threat to public health. The aim of this study was to: update antimicrobial susceptibility data of Neisseria gonorrhoeae recently isolated in Nanjing, China and identify specific deteminants of antimicrobial resistance and gentoypes of isolates with decreased sensitivity to ceftriaxone. METHODS: 334 N. gonorrhoeae isolates were collected consecutively from symptomatic men attending the Nanjing STD Clinic between April 2011 and December 2012. The minimum inhibitory concentrations (MICs) for penicillin, tetracycline, ciprofloxacin, spectinomycin and ceftriaxone were determined by agar plate dilution for each isolate. Penicillinase-producing N. gonorrhoeae (PPNG) and tetracycline-resistant N. gonorrhoeae (TRNG) were examined and typed for ß-lactamase and tetM encoding plasmids respectively. Isolates that displayed elevated MICs to ceftriaxone (MIC ≥0.125 mg/L) were also tested for mutations in penA, mtrR, porB1b, ponA and pilQ genes and characterized by Neisseria gonorrhoeae multi-antigen sequence typing (NG-MAST). RESULTS: 98.8% (330/334) of N. gonorrhoeae isolates were resistant to ciprofloxacin; 97.9% (327/334) to tetracycline and 67.7% (226/334) to penicillin. All isolates were susceptible to ceftriaxone (MIC ≤0.25 mg/L) and spectinomycin (MIC ≤32 mg/L). Plasmid mediated resistance was exhibited by 175/334 (52%) of isolates: 120/334 (36%) of isolates were PPNG and 104/334 (31%) were TRNG. 90.0% (108/120) of PPNG isolates carried the Asia type ß-lactamase encoding plasmid and 96% (100/104) of TRNG isolates carried the Dutch type tetM containing plasmid. Elevated MICs for ceftriaxone were present in 15 (4.5%) isolates; multiple mutations were found in penA, mtrR, porB1b and ponA genes. The 15 isolates were distributed into diverse NG-MAST sequence types; four different non-mosaic penA alleles were identified, including one new type. CONCLUSIONS: N. gonorrhoeae isolates in Nanjing generally retained similar antimicrobial resistance patterns to isolates obtained five years ago. Fluctuations in resistance plasmid profiles imply that genetic exchange among gonococcal strains is ongoing and is frequent. Ceftriaxone and spectinomycin remain treatments of choice of gonorrhea in Nanjing, however, decreased susceptibility to ceftriaxone and rising MICs for spectinomycin of N. gonorrhoeae isolates underscore the importance of maintaining surveillance for AMR (both phenotypic and genotypic).

RNA-dependent RNA polymerase 6 of rice (Oryza sativa) plays role in host defense against negative-strand RNA virus, Rice stripe virus.

RNA-dependent RNA polymerases (RDRs) from fungi, plants and some invertebrate animals play fundamental roles in antiviral defense. Here, we investigated the role of RDR6 in the defense of economically important rice plants against a negative-strand RNA virus (Rice stripe virus, RSV) that causes enormous crop damage. In three independent transgenic lines (OsRDR6AS line A, B and C) in which OsRDR6 transcription levels were reduced by 70-80% through antisense silencing, the infection and disease symptoms of RSV were shown to be significantly enhanced. The hypersusceptibilities of the OsRDR6AS plants were attributed not to enhanced insect infestation but to enhanced virus infection. The rise in symptoms was associated with the increased accumulation of RSV genomic RNA in the OsRDR6AS plants. The deep sequencing data showed reduced RSV-derived siRNA accumulation in the OsRDR6AS plants compared with the wild type plants. This is the first report of the antiviral role of a RDR in a monocot crop plant in the defense against a negative-strand RNA virus and significantly expands upon the current knowledge of the antiviral roles of RDRs in the defense against different types of viral genomes in numerous groups of plants.