GSTO1 aggravates EGFR-TKIs resistance and tumor metastasis via deglutathionylation of NPM1 in lung adenocarcinoma.

Despite significantly improved clinical outcomes in EGFR-mutant lung adenocarcinoma, all patients develop acquired resistance and malignancy on the treatment of EGFR tyrosine kinase inhibitors (EGFR-TKIs). Understanding the resistance mechanisms is crucial to uncover novel therapeutic targets to improve the efficacy of EGFR-TKI treatment. Here, integrated analysis using RNA-Seq and shRNAs metabolic screening reveals glutathione S-transferase omega 1 (GSTO1) as one of the key metabolic enzymes that is required for EGFR-TKIs resistance in lung adenocarcinoma cells. Aberrant upregulation of GSTO1 confers EGFR-TKIs resistance and tumor metastasis in vitro and in vivo dependent on its active-site cysteine 32 (C32). Pharmacological inhibition or knockdown of GSTO1 restores sensitivity to EGFR-TKIs and synergistically enhances tumoricidal effects. Importantly, nucleophosmin 1 (NPM1) cysteine 104 is deglutathionylated by GSTO1 through its active C32 site, which leads to activation of the AKT/NF-κB signaling pathway. In addition, clinical data illustrates that GSTO1 level is positively correlated with NPM1 level, NF-κB-mediated transcriptions and progression of human lung adenocarcinoma. Overall, our study highlights a novel mechanism of GSTO1 mediating EGFR-TKIs resistance and malignant progression via protein deglutathionylation, and GSTO1/NPM1/AKT/NF-κB axis as a potential therapeutic vulnerability in lung adenocarcinoma.

Evaluation of the diagnostic performance of an immunochromatographic test for Chlamydia trachomatis.

Objectives: To evaluate the diagnostic performance of different brands of immunochromatographic test (ICT) reagents for Chlamydia trachomatis using homogenized samples to provide a reference for reagent quality control. Methods: Eight commercially available ICT reagents were evaluated, of which three used the latex method and five used the colloidal gold method. Analytical performance evaluation using a pure culture broth of C. trachomatis, as well as clinical application validation using cervical epithelial cell samples acquired from the research subjects, were conducted. The concentration of C. trachomatis was quantified using a nucleic acid amplification test. Results: The limit of detection (LOD) of different ICT reagents in the analytical performance evaluation varied from 9.5 × 103 to 1 × 105 IFU/mL, and only one reagent met the LOD specified in the manufacturer's instructions. Likewise, only one reagent in the clinical application validation achieved the analytical LOD, four reagents were 2.1-4.2-fold of the analytical LODs, and three reagents failed to detect positive results in clinical samples. Conclusions: The diagnostic performance of different methods and different brands of ICT reagents in clinical practice was different from the manufacturer's instructions and the results of laboratory evaluation. The diagnostic performance of reagents should be evaluated before they are actually used in clinical practice.

Identification of high-level ceftriaxone-resistant Neisseria gonorrhoeae isolates with diverse penA alleles in Zhejiang, China.

OBJECTIVES: The prevalence of ceftriaxone-resistant Neisseria gonorrhoeae poses a significant threat to the effectiveness of gonorrhoea treatment. The aim of the present study was to analyse the characteristics of ceftriaxone-resistant N. gonorrhoeae, with a specific focus on high-level ceftriaxone-resistant strains. METHODS: A total of 207 strains of N. gonorrhoeae were collected from hospitals in Zhejiang, China, between 2019 and 2020. From this collection, we selected 8 strains of ceftriaxone-resistant N. gonorrhoeae for whole-genome sequencing, genotyping, and molecular profile analysis. For clonal strains (FC428-like), we conducted a phylogenetic analysis to understand their origin and evolutionary path. RESULTS: Among the selected strains, 5 demonstrated high-level ceftriaxone resistance (MIC 1-2 mg/L). The genotyping results showed that these isolates had a higher diversity of penA alleles than expected. Four isolates had mosaic penA-60.001 allele and the remaining four had different non-mosaic penA alleles. Phylogenetic analysis suggested that the emergence of FC428-like clones containing penA-60.001 may result from further dissemination of different FC428 subclones from different regions of China. The identification of high-level ceftriaxone resistance in non-mosaic penA gonococci, specifically in the ZJ20-3 isolate (penA-21.001) with an MIC of 2 mg/L, is a groundbreaking discovery. CONCLUSIONS: We present a comprehensive analysis of ceftriaxone-resistant N. gonorrhoeae isolates in Zhejiang, highlighting a significant diversity of penA alleles. The identification of strains exhibiting resistance to ceftriaxone at high levels in our study underscores the potential threat to existing protocols for gonorrhoea treatment. Consequently, we strongly emphasize the urgent need to enhance surveillance initiatives focused on ceftriaxone-resistant N. gonorrhoeae.

Identification of ceftriaxone-resistant Neisseria gonorrhoeae FC428 clone and isolates harboring a novel mosaic penA gene in Chengdu in 2019-2020.

BACKGROUND: Antimicrobial resistance in gonorrhea has become a growing global public health burden. Neisseria gonorrhoeae isolates with resistance to ceftriaxone, the last remaining first-line option, represent an emerging threat of untreatable gonorrhea. METHODS: A total of ten ceftriaxone-resistant N. gonorrhoeae FC428 isolates and two isolates harboring a novel mosaic penA-232.001 allele from 160 gonococcal isolates in Chengdu in 2019-2020 was described in the present study. Multilocus sequence typing (MLST) and N. gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) were performed to characterize the isolates. Whole genome sequencing and maximum-likelihood method were performed to infer how the genetic phylogenetic tree of these isolates looks like. Recombination analysis was performed using the RDP4 software. This study was registered in the Chinese Clinical Trial Registry (ChiCTR2100048771, registration date: 20210716). RESULTS: The genetic phylogeny showed that the ten FC428 isolates sporadically clustered into different phylogenetic clades, suggesting different introductions and local transmission of FC428. Two isolates showed close genetic relatedness to ceftriaxone-resistant clone A8806, which was only reported from Australia in 2013. Homologous recombination events were detected in penA between Neisseria gonorrhoeae and commensal Neisseria species (N. perflava and N. polysaccharea), providing evidence of commensal Neisseria species might serve as reservoirs of ceftriaxone resistance-mediating penA sequences in clinical gonococcal strains. CONCLUSIONS: Our results demonstrate further dissemination of FC428 in China and resurgence risks of sporadic ceftriaxone-resistant A8806 to become the next clone to spread.

The optimum condition of the toluidine red unheated serum test for the replacement of the venereal disease research laboratory test in cerebrospinal fluid for neurosyphilis diagnosis.

Background: The cerebrospinal fluid (CSF) venereal disease research laboratory (VDRL) test remains the standard for the laboratory diagnosis of neurosyphilis. The toluidine red unheated serum test (TRUST) is an alternative to the VDRL test as a serological test for syphilis, but it lacks guidelines for its use in CSF for neurosyphilis diagnosis. Methods: A total of 210 suspected neurosyphilis patients were included, consisting of 124 neurosyphilis patients and 86 syphilis/non-neurosyphilis patients. The TRUST was modified into the CSF-TRUST-10 test with 10 µL of antigen by referring to the CSF-VDRL test, and the CSF-TRUST-17 test with 17 µL of antigen by referring to its procedures in serum. The diagnostic performance of the CSF-TRUST-10 and CSF-TRUST-17 tests and the concordance between them and the CSF-VDRL test were evaluated. Results: The diagnostic performance of the CSF-TRUST-10 and CSF-TRUST-17 tests for diagnosing neurosyphilis were comparable to the CSF-VDRL test, as well as the positive rate. The agreement rate was 98.7% between the qualitative CSF-TRUST-10 and CSF-VDRL tests. A total of 91.4% of the quantitative CSF-TRUST-10 results were consistent with the CSF-VDRL test, and the discordant results were no more than two titres. The agreement rate was 98.1% between the qualitative CSF-TRUST-17 and CSF-VDRL tests and 87.6% between the quantitative CSF-TRUST-17 and CSF-VDRL tests. Conclusions: The CSF-TRUST with 10 µL of antigen could be an alternative for the CSF-VDRL test for neurosyphilis diagnosis. Our results provide a basis for using the TRUST to guide the diagnosis of neurosyphilis.

Multicentre Clinical Evaluation of a Molecular Diagnostic Assay to Identify Neisseria gonorrhoeae Infection and Detect Antimicrobial Resistance.

OBJECTIVES: Antimicrobial resistance (AMR) in Neisseria gonorrhoeae (N. gonorrhoeae) is an urgent threat to public health, with the emergence of highly resistant strains such as the FC428 clone. This study aimed to evaluate the high-resolution melting assay of N. gonorrhoeae AMR (HRM-NG-AMR) for diagnosing N. gonorrhoeae infection and detecting extended-spectrum cephalosporins and azithromycin resistance. METHODS: A multicentre collection of 1488 samples, including 770 isolates and 718 urogenital swabs, was used to evaluate the performance of the HRM-NG-AMR assay. The presence of N. gonorrhoeae was confirmed by culture. Minimum inhibitory concentrations of antibiotics against the tested isolates were determined using the agar dilution method. RESULTS: Regarding N. gonorrhoeae identification, HRM-NG-AMR had a sensitivity of 95.15% (95% CI 91.65-97.28) and a specificity of 96.44% (95% CI 94.17-97.89) using culture as standard. Regarding AMR detection, the specificity ranged from 96.29% (95% CI 94.57-97.50) for cefixime to 99.52% (95% CI 98.68-99.85) for azithromycin. Additionally, the sensitivity ranged from 31.34% (95% CI 20.87-43.97) for azithromycin to 79.10% (95% CI 63.52-89.42) for ceftriaxone. It was determined that 664 of 672 (98.81%) and 615 of 672 (91.52%) N. gonorrhoeae isolates were susceptible to ceftriaxone and cefixime, respectively, by detecting non-mosaic penA. Lastly, 40 genotypic FC428-related strains with the penA-60.001 allele were accurately identified. CONCLUSIONS: The HRM-NG-AMR assay showed promising diagnostic performance for detecting N. gonorrhoeae infection and predicting AMR. This study aimed to evaluate the application of this assay in the clinical setting to enhance AMR surveillance and treatment intervention.

Photodynamic inactivation and its application in food preservation.

Food incidents caused by various foodborne pathogenic bacteria are posing a major threat to human health. The traditional thermal and chemical-based procedures applied for microbial control in the food industry cause adverse effects on food quality and bacterial resistance. As a new means of innovative sterilization technology, photodynamic inactivation (PDI) has gained significant attention due to excellent sterilization effect, environmental friendliness, safety, and low cost. This review analyses new developments in recent years for PDI systems applied to the food preservation. The fundamentals of photosensitization mechanism, the development of photosensitizers and light source selection are discussed. The application of PDI in food preservation are presented, with the main emphasis on the natural photosensitizers and its application to inactivate in vitro and in vivo microorganisms in food matrixes such as fresh vegetable, fruits, seafood, and poultry. The challenges and future research directions facing the application of this technology to food systems have been proposed. This review will provide reference for combating microbial contamination in food industry.

Metabolic and Nonmetabolic Functions of PSAT1 Coordinate Signaling Cascades to Confer EGFR Inhibitor Resistance and Drive Progression in Lung Adenocarcinoma.

Emerging evidence demonstrates that the dysregulated metabolic enzymes can accelerate tumorigenesis and progression via both metabolic and nonmetabolic functions. Further elucidation of the role of metabolic enzymes in EGFR inhibitor resistance and metastasis, two of the leading causes of death in lung adenocarcinoma, could help improve patient outcomes. Here, we found that aberrant upregulation of phosphoserine aminotransferase 1 (PSAT1) confers erlotinib resistance and tumor metastasis in lung adenocarcinoma. Depletion of PSAT1 restored sensitivity to erlotinib and synergistically augmented the tumoricidal effect. Mechanistically, inhibition of PSAT1 activated the ROS-dependent JNK/c-Jun pathway to induce cell apoptosis. In addition, PSAT1 interacted with IQGAP1, subsequently activating STAT3-mediated cell migration independent of its metabolic activity. Clinical analyses showed that PSAT1 expression positively correlated with the progression of human lung adenocarcinoma. Collectively, these findings reveal the multifunctionality of PSAT1 in promoting tumor malignancy through its metabolic and nonmetabolic activities. SIGNIFICANCE: Metabolic and nonmetabolic functions of PSAT1 confer EGFR inhibitor resistance and promote metastasis in lung adenocarcinoma, suggesting therapeutic targeting of PSAT1 may attenuate the malignant features of lung cancer.

Co-crystallization of curcumin for improved photodynamic inactivation of Vibrio parahaemolyticus and its application for the preservation of cooked clams.

Curcumin (CUR) is a natural active product widely used as photosensitizer in photodynamic inactivation (PDI) due to low toxicity and low cost. However, the main challenge that limit the efficacy of CUR in PDI are its low solubility in water medium and hence low bioavailability. The co-crystallization is a novel process enables improvements in physicochemical properties such as solubility and bioavailability of water insoluble compound by the incidence of molecular interactions between the active pharmaceutical ingredient and conformer. The main objective of this work is to produce CUR-d-Tyr co-crystal (CDC) by co-crystallization technique using d-Tyrosine (d-Tyr) as the conformer in order to increase CUR water solubility as well as antimicrobial photodynamic activity. CDC presented a different crystalline structure compared with pure CUR. The solubility of CDC in water medium was about 16.5 times greater than pure CUR. The co-crystallization process increased CUR-mediated photodynamic inactivation efficacy of Vibrio parahaemolyticus (V. parahaemolyticus), probably due to alterations in its bioavailability. Moreover, cell membrane damage and production of cytotoxic singlet oxygen (1O2) was proved as main photosensitization mechanism. Furthermore, the application of CDC-mediated PDI on cooked clam reduced weightlessness of cooked clams, inhibited lipid oxidation, and maintained a better appearance, serving as a promising preservation techniques in food industry.

Which Is the Optimum Antigen Concentration for the Venereal Disease Research Laboratory Test of Cerebrospinal Fluid for Neurosyphilis Diagnosis: 10 or 17 µL?

The manufacturer's instructions for the venereal disease research laboratory (VDRL) antigen test for diagnosing neurosyphilis describe testing of serum samples and do not include procedures for cerebrospinal fluid (CSF) testing. This study compared the CSF-VDRL test with 10 µL of antigen (CSF-VDRL-10) according to the American Public Health Association to the CSF-VDRL test with 17 µL of antigen (CSF-VDRL-17) according to the VDRL serum procedure. A total of 121 neurosyphilis patients and 86 syphilis/non-neurosyphilis patients were included. The sensitivities of the CSF-VDRL-10 and CSF-VDRL-17 tests were comparable for neurosyphilis diagnosis. The positive rate of the CSF-VDRL-17 test was higher than that of the CSF-VDRL-10 test. In all, 78.3% of the quantitative CSF-VDRL-17 results were consistent with those of the CSF-VDRL-10 test, 18.4% exhibited one-titer higher results than those of the CSF-VDRL-10 test, and 3.4% had positive CSF-VDRL-17 results but negative CSF-VDRL-10 results. The CSF-VDRL test with 17 µL of antigen was more sensitive, and it is worth performing longitudinal studies to understand its practical implications.

A review of bacterial biofilm control by physical strategies.

Biofilms are multicellular communities of microorganisms held together by a self-produced extracellular matrix, which contribute to hygiene problems in the food and medical fields. Both spoilage and pathogenic bacteria that grow in the complex structure of biofilm are more resistant to harsh environmental conditions and conventional antimicrobial agents. Therefore, it is important to develop eco-friendly preventive methodologies to eliminate biofilms from foods and food contact equipment. The present paper gives an overview of the current physical methods for biofilm control and removal. Current physical strategies adopted for the anti-biofilm treatment mainly focused on use of ultrasound power, electric or magnetic field, plasma, and irradiation. Furthermore, the mechanisms of anti-biofilm action and application of different physical methods are discussed. Physical strategies make it possible to combat biofilm without the use of biocidal agents. The remarkable microbiocidal properties of physical strategies are promising tools for antimicrobial applications.

Atomevo: a web server combining protein modelling, docking, molecular dynamic simulation and MMPBSA analysis of Candida antarctica lipase B (CalB) fusion protein.

Although current computational biology software is available and has prompted the development of enzyme-substrates simulation, they are difficult to install and inconvenient to use. This makes the time-consuming and error-prone process. By far there is still a lack of a complete tool which can provide a one-stop service for the enzyme-substrates simulation process. Hence, in this study, several computational biology software was extended development and integrated as a website toolbox named Atomevo. The Atomevo is a free web server providing a user-friendly interface for enzyme-substrates simulation: (1) protein homologous modeling; (2) parallel docking module of Autodock Vina 1.2; (3) automatic modeling builder for Gromacs molecular dynamics simulation package; and (4) Molecular Mechanics/Poisson-Boltzmann Surface Area (MMPBSA) analysis module for receptor-ligand binding affinity analysis. We officially launched the web server and provided instructions through a case for the design and simulation of Candida antarctica lipase B (CalB) fusion protein called Maltose Binding Protein-Thioredoxin A-Candida antarctica lipase B (MBP-TrxA-CalB).

HKB99, an allosteric inhibitor of phosphoglycerate mutase 1, suppresses invasive pseudopodia formation and upregulates plasminogen activator inhibitor-2 in erlotinib-resistant non-small cell lung cancer cells.

Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as erlotinib, remains a major challenge in the targeted therapy of non-small cell lung cancer (NSCLC). HKB99 is a novel allosteric inhibitor of phosphoglycerate mutase 1 (PGAM1) that preferentially suppresses cell proliferation and induces more apoptosis in acquired erlotinib-resistant HCC827ER cells compared with its parental HCC827 cells. In this study we identified the molecular biomarkers for HKB99 response in erlotinib-resistant HCC827ER cells. We showed that HCC827ER cells displayed enhanced invasive pseudopodia structures as well as downregulated plasminogen activator inhibitor-2 (PAI-2). Meanwhile, PAI-2 knockdown by siPAI-2 candidates decreased the sensitivity of HCC827 parental cells to erlotinib. Moreover, HKB99 (5 µM) preferentially inhibited the invasive pseudopodia formation and increased the level of PAI-2 in HCC827ER cells. Collectively, this study provides new insight into the role of PAI-2 in regulating the sensitivity of erlotinib resistant NSCLC cells to PGAM1 inhibitor. Furthermore, PAI-2 level might be considered as a potential biomarker for predicting the efficacy of the PGAM1 allosteric inhibitor on the erlotinib resistant NSCLC cells.

Shanghai Neisseria gonorrhoeae Isolates Exhibit Resistance to Extended-Spectrum Cephalosporins and Clonal Distribution.

The emergence of Neisseria gonorrhoeae strains with resistance (R) to extended-spectrum cephalosporins (ESCsR) represents a public health threat of untreatable gonococcal infections. This study was designed to determine the prevalence and molecular mechanisms of ESCR of Shanghai N. gonorrhoeae isolates. A total of 366 N. gonorrhoeae isolates were collected in 2017 in Shanghai. Susceptibility to ceftriaxone (CRO), cefixime (CFM), azithromycin (AZM), ciprofloxacin (CIP), spectinomycin, penicillin, and tetracycline was determined using the agar dilution method. A subset of 124 isolates was subjected to phylogenetic analysis for nine antimicrobial resistance-associated genes, i.e., penA, porB, ponA, mtrR, 23S rRNA, gyrA, parC, 16S rRNA, and rpsE. Approximately 20.0% of the isolates exhibited CFMR [minimum inhibitory concentration (MIC) >0.125 mg/L], and 5.5% were CROR (MIC > 0.125 mg/L). In total, 72.7% of ESCR isolates were clonal and associated with mosaic penA 10 and 60 alleles. Non-mosaic penA 18 allele and substitutions of PenA A501T, G542S, and PorB1b G213S/Y were observed in non-clonal ESCR. Approximately 6.8% of the isolates showed AZM MIC above the epidemiological cutoff (ECOFF, 1 mg/L), were associated with 23S rRNA A2059G mutation, and did not exhibit clonal distribution. Almost all isolates were CIPR (resistance to ciprofloxacin) and associated with GyrA-91/92 and ParC-85/86/87/88/89/91 alterations. Isolates with ParC S88P substitution were clustered into the ESCR clade. The Shanghai isolates exhibited a high level of ESCR and distinct resistant patterns.

Comparative Proteomics of Extended-Spectrum Cephalosporin-Resistant Neisseria gonorrhoeae Isolates Demonstrates Altered Protein Synthesis, Metabolism, Substance Transport, and Membrane Permeability.

Neisseria gonorrhoeae isolates exhibit resistance to extended-spectrum cephalosporins (ESCs), the last remaining option for first-line empirical monotherapy. Here, we investigated the proteomic profiles of N. gonorrhoeae clinical isolates with ESC-resistance to support exploration of the antimicrobial resistance mechanisms for N. gonorrhoeae. We used comparative iTRAQ quantitative proteomics to investigate differential protein expression of three ESC-resistant N. gonorrhoeae clinical isolates using N. gonorrhoeae ATCC49226 as a reference strain. The expression of 40 proteins was downregulated and expression of 56 proteins was upregulated in all three ESC-resistant N. gonorrhoeae isolates. Proteins with predicted function of translation, ribosomal structure and biogenesis, as well as components of the Type IV secretory systems, were significantly upregulated. Two differentially expressed proteins of ABC transporters were also reported by other teams in proteomics studies of N. gonorrhoeae isolates under antimicrobial stress conditions. Differentially expressed proteins are involved in energy production and metabolism of carbohydrates and amino acids. Our results indicated that amino acid and carbohydrate metabolism, cell membrane structure, interbacterial DNA transfer, and ribosome components might be involved in mediating ESC-resistance in N. gonorrhoeae. These findings facilitate a better understanding of the mechanisms of ESC-resistance in N. gonorrhoeae and provide useful information for identifying novel targets in the development of antimicrobials against N. gonorrhoeae.

NG-STAR genotypes are associated with MDR in Neisseria gonorrhoeae isolates collected in 2017 in Shanghai.

OBJECTIVES: To determine the association of Neisseria gonorrhoeae antimicrobial resistance and genotypes using N. gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR). METHODS: We characterized 124 N. gonorrhoeae isolates for their antimicrobial susceptibility profiles and NG-STAR ST characteristics using the guidelines of CLSI and EUCAST. The NG-STAR STs of seven loci were analysed. N. gonorrhoeae multiantigen sequence typing (NG-MAST) and MLST analysis was conducted in isolates with specific NG-STAR STs. RESULTS: NG-STAR differentiated 124 N. gonorrhoeae isolates into 84 STs, of which 66 STs were novel to the NG-STAR database. NG-STAR ST-199, ST-348, ST-428, ST-497 and ST-1138 were the predominant STs. Three N. gonorrhoeae isolates with ceftriaxone and cefixime MICs ≥1.0 mg/L were grouped as NG-STAR ST-233. NG-STAR ST-202 isolates (n=4) were associated with high azithromycin MICs and had an identical NG-MAST ST. The NG-STAR ST-348 group (n=5) comprised more isolates with reduced susceptibility to cefixime (n=4) than cefixime-susceptible isolates (n=1). CONCLUSIONS: NG-STAR analysis differentiated N. gonorrhoeae isolates in settings with a high prevalence of antimicrobial resistance. Specific NG-STAR STs are associated with reduced susceptibility to ceftriaxone or cefixime and resistance to azithromycin in N. gonorrhoeae.

A Novel Allosteric Inhibitor of Phosphoglycerate Mutase 1 Suppresses Growth and Metastasis of Non-Small-Cell Lung Cancer.

Phosphoglycerate mutase 1 (PGAM1) plays a pivotal role in cancer metabolism and tumor progression via its metabolic activity and interaction with other proteins like α-smooth muscle actin (ACTA2). Allosteric regulation is considered to be an innovative strategy to discover a highly selective and potent inhibitor targeting PGAM1. Here, we identified a novel PGAM1 allosteric inhibitor, HKB99, via structure-based optimization. HKB99 acted to allosterically block conformational change of PGAM1 during catalytic process and PGAM1-ACTA2 interaction. HKB99 suppressed tumor growth and metastasis and overcame erlotinib resistance in non-small-cell lung cancer (NSCLC). Mechanistically, HKB99 enhanced the oxidative stress and altered multiple signaling pathways including the activation of JNK/c-Jun and suppression of AKT and ERK. Collectively, the study highlights the potential of PGAM1 as a therapeutic target in NSCLC and reveals a distinct mechanism by which HKB99 inhibits both metabolic activity and nonmetabolic function of PGAM1 by allosteric regulation.

A Whole-genome Sequencing Analysis of Neisseria gonorrhoeae Isolates in China: An Observational Study.

BACKGROUND: Tracking the spread of the Neisseria gonorrhoeae strains with decreased susceptibility or resistance to cephalosporins is a major priority for global surveillance programmes. Whole-genome sequencing (WGS) has been widely used by increasing countries in North America, Europe, and Pacific to determine the decreased susceptible or resistance determinants of Neisseria gonorrhoeae, track the spread of these determinants throughout the gonococcal population at national or regional level. However, no studies to date have examined the genomic epidemiology of gonorrhea in Asia where the antimicrobial resistant strains of Neisseria gonorrhoeae appears to have emerged before disseminating the strains globally. METHODS: We obtained clinical isolates and data from the China Gonococcal Resistance Surveillance Programme (China-GRSP) from 2012 to 2013. We sequenced the genomes of 435 clinical isolates of Neisseria gonorrhoeae, including 112 (25.6%) isolates with decreased susceptibility to ceftriaxone (Cfx-DS). We assessed the association between antimicrobial resistance genotype and phenotype. We also compared our data with the whole genome data of the isolates from the USA and the UK in the GenBank. FINDINGS: The most prevalent MLST STs in our gonococcal population were MLST ST7827 (n = 74), followed by ST7365 (n = 58), ST1600 (n = 38), ST7367 (n = 35), and ST7363 (n = 29). MLST ST1901 which was reported as the predominant ST in the US was not found in our population. A total of 2512 strains, including additional 2077 published NG strains, were further included for phylogenetic analysis. It generated two distinct lineages - lineage 1 and lineage 2. Analysis of MLST ST1901 in the database indicate that most of MLST ST1901 isolates in the lineage2.6 were Cfx-DS isolates while all isolates in the lineage 2.1 were sensitive to ceftriaxone (77/110 vs. 0/13; p < 0.001). ST1901/lineage 2.6 is a ceftriaxone resistant clone which cannot distinguished by MLST genotyping. In the isolates from our study, the MICs of ceftriaxone for ST7363/lineage 2.6 isolates ranged from 0.008-0.125 mg/L (mean ±â€¯SD; 0.054 ±â€¯0.043 mg/L) while those for ST7363/lineage 2.8 isolates ranged from 0.032-0.250 mg/L (0.134 ±â€¯0.085 mg/L). All ST7363/lineage 2.8 isolates contained penA mosaic alleles. INTERPRETATION: To our knowledge, current study is the first WGS-based analysis of gonococcal population at national level in Asia. China harbors the different predominant clones associated with decreased susceptibility to ceftriaxone from those clones circulated in other regions. The findings from the study can be not only used as baseline data for future studies in China but also contributable to our understanding on spread of N. gonorrhoeae and its resistant strains at regional and global levels. FUNDING: The Chinese Academy Medical Sciences (CAMS) Initiative for Innovative Medicine.