Changing antimicrobial susceptibility and molecular characterisation of Neisseria gonorrhoeae isolates in Guangdong, China: in a background of rapidly rising epidemic

Global trends of antimicrobial resistance rates in Neisseria gonorrhoeae: a systematic review and meta-analysis

Background

Antimicrobial resistance (AMR) of Neisseria gonorrhoeae (NG) is a significant public health concern.

Objective

The objective of our study was to assess global AMR rates and test them both temporally and geographically.

Methods

We conducted a systematic search of relevant reports from international databases up to 2021. The R statistical package was used for all statistical analyses.

Results

A total of 225 articles were analyzed, and 432,880 NG isolates were examined. The weighted pooled resistance (WPR) rate of different antibiotics was as follows: ciprofloxacin, 51.6%; tetracycline, 45.4%; trimethoprim/sulfamethoxazole, 42.4%; chloramphenicol, 4.1%; kanamycin, 2.1%; gentamicin, 0.6%; and spectinomycin, 0.3%. The resistance to spectinomycin, gentamicin, and kanamycin decreased over time. Significant differences in antibiotic resistance rates were found between the countries.

Conclusion

Our findings reveal a continuous increase in resistance to some antibiotics (tetracycline and ciprofloxacin) historically used for gonorrhea, even after discontinuation. However, encouraging trends of decreasing resistance to spectinomycin, gentamicin, and kanamycin were observed. Continued global monitoring of AMR profiles in NG isolates is essential for informing appropriate treatment strategies and mitigating the threat of untreatable gonorrhea.

Evaluating the efficacy of different antibiotics against Neisseria gonorrhoeae: a pharmacokinetic/pharmacodynamic analysis using Monte Carlo simulation

BACKGROUND

With the widespread use of antibiotics, antimicrobial resistance in Neisseria gonorrhoeae is worsening. The objective of this study was to evaluate the efficacy changes of seven antibiotics in the treatment of N. gonorrhoeae by using Monte Carlo simulation combined with pharmacokinetics/pharmacodynamics/ (PK/PD).

METHODS

The minimum inhibitory concentration (MIC) of antibiotics against clinical isolates from 2013 to 2020 in Nanjing, China, was determined by agar dilution method. The probability of target attainment (PTA) was estimated at each MIC value and the cumulative fraction of response (CFR) was calculated to evaluate the efficacy of these regimens.

RESULTS

All dosage regimens of seven antibiotics achieved PTAs ≥ 90% for MIC ≤ 0.06 µg/ml. But when the MIC was increased to 1 µg/ml, PTAs at each MIC value exceeded 90% only for ceftriaxone 1,000 mg and 2,000 mg, zoliflodacin 2,000 mg and 3,000 mg. Among them, the CFR values of each dosing regimen against N. gonorrhoeae only for ceftriaxone, cefixime and zoliflodacin were ≥ 90% in Nanjing from 2013 to 2020.

CONCLUSIONS

Cephalosporins are still the first-line drugs in the treatment of gonorrhea. However, the elevated MIC values of cephalosporins can lead to decline in clinical efficacy of the conventional dose regimens, and increasing the dose of ceftriaxone to 1,000 mg-2,000 mg may improve the efficacy. In addition, zoliflodacin is possible to be a potential therapeutic agent in the future.

Point-of-care detection of Neisseria gonorrhoeae based on RPA-CRISPR/Cas12a

Gonorrhea, caused by Neisseria gonorrhoeae (N. gonorrhoeae), is a persistent global public health threat. The development of low-cost, point-of-care testing is crucial for gonorrhea control, especially in regions with limited medical facilities. In this study, we integrated CRISPR/Cas12a reaction with recombinase polymerase amplification (RPA) to provide a simple and adaptable molecular detection method for N. gonorrhoeae. The RPA-Cas12a-based detection system developed in this study enables rapid detection of N. gonorrhoeae within 1 h without the use of specialized equipment. This method is highly specific for identifying N. gonorrhoeae without cross-reactivity with other prevalent pathogens. Furthermore, in the evaluation of 24 clinical samples, the detection system demonstrates a 100% concordance rate with traditional culture, which is being used clinically as a reference method. Overall, the RPA-Cas12a-based N. gonorrhoeae detection has the advantages of rapidity, portability, low-cost, no special equipment required, and strong operability, and has a high potential for application as a self-testing and point-of-care diagnosis, which is critical for the clinical management of gonorrhea in developing countries lacking medical equipment.

16S rRNA gene sequencing reveals an altered composition of gut microbiota in children with Mycoplasma pneumoniae pneumonia treated with azithromycin

Mycoplasma pneumoniae is one of the most important pathogens causing community acquired pneumonia in children, and the pathogenic mechanism of M. pneumoniae infection is complex. Azithromycin is an effective agent for treating the acquired lower respiratory tract infection and urogenital tract infection with slight adverse reactions. This study aimed to compare the intestinal microflora before (PP1) and after azithromycin intervention (PP2) in children with pneumonia caused by M. pneumoniae, combined with body fluid biochemical analysis to determine the intestinal flora affecting the progress of the disease. Fifteen children diagnosed with M. pneumoniae pneumonia were recruited. The fecal samples and clinical biochemical data were collected. 16S rRNA gene amplicon sequencing and bioinformatics analysis were conducted by the Beijing Genomics Institute. The operational taxonomic unit abundance analysis showed significant differences between the two groups. The species richness analysis showed differences in class, family, genus, order, species, and phylum. The abundance of Haemophilus, Pasteurellales, and Pasteurellaceae was found to be significantly higher in the PP1 group. The Pearson correlation analysis showed that the microbes strongly correlated with the clinical features. 16S rRNA gene sequencing data revealed altered composition of gut microbiota in children with M. pneumoniae pneumonia treated with azithromycin. The altered expression of microbes correlated with clinical features, which might help diagnose and treat the disease.

Global status of Azithromycin and Erythromycin Resistance Rates in Neisseria gonorrhoeae: A Systematic Review and Meta-analysis

Background: The widespread development of antibiotic resistance or decreased susceptibility in Neisseria gonorrhoeae (NG) infection is a global and significant human public health issue. Objectives: Therefore, this meta-analysis aimed to estimate worldwide resistance rates of NG to the azithromycin and erythromycin according to years, regions, and antimicrobial susceptibility testing (AST). Methods: We systematically searched the published studies in PubMed, Scopus, and Embase from 1988 to 2021. All analyses were conducted using Stata software. Results: The 134 reports included in the meta-analysis were performed in 51 countries and examined 165,172 NG isolates. Most of the included studies were from Asia (50 studies) and Europe (46 studies). In the metadata, the global prevalence over the past 30 years were 6% for azithromycin and 48% for erythromycin. There was substantial change in the prevalence of macrolides NG resistance over time (P <0.01). In this metadata, among 58 countries reporting resistance data for azithromycin, 17 (29.3%) countries reported that >5% of specimens had azithromycin resistance. Conclusions: The implications of this study emphasize the rigorous or improved antimicrobial stewardship, early diagnosis, contact tracing, and enhanced intensive global surveillance system are crucial for control of further spreading of gonococcal emergence of antimicrobial resistance (AMR).

High prevalence of blaTEM-135 and genetic epidemiology of blaTEM-135-carrying Neisseria gonorrhoeae isolates in Shandong, China, 2017-19

BACKGROUND

Only one additional specific SNP in blaTEM-135 in penicillinase-producing Neisseria gonorrhoeae (PPNG) isolates is required for TEM-135 to evolve into an ESBL that is capable of degrading all extended-spectrum cephalosporins (ESCs).

METHODS

Identification of the blaTEM-135 gene was achieved by performing a mismatch amplification mutation assay PCR. PPNG isolates were then genotyped using MLST and N. gonorrhoeae multiantigen sequence typing (NG-MAST) techniques. Finally, phylogenetic analyses based on MLST and NG-MAST were performed on all of the PPNG isolates, and genogroups were classified according to the phylogenetic relatedness on the basis of each MLST and NG-MAST gene typing and the blaTEM allele varieties.

RESULTS

Among the 197 PPNG isolates, one (0.5%) isolate possessed the blaTEM-220 allele, 90 (45.7%) possessed the blaTEM-135 allele, and 106 (53.8%) possessed the blaTEM-1 allele. Among the blaTEM-135-carrying PPNG isolates, MLST ST8109 (n = 30) and NG-MAST ST12199 (n = 5), ST12754 (n = 5) and ST15073 (n = 5) were the most prevalent in the Shandong province of China. The phylogenetic analyses revealed that MLST ST8109, ST8140 and ST14417, mainly carrying the blaTEM-135 allele, belonged to the same genogroup, G1, while NG-MAST ST12199 and ST15073, mainly carrying the blaTEM-135 allele, belonged to the same genogroup, Ga.

CONCLUSIONS

This study has shown that the molecular epidemiology of PPNG isolates carrying the blaTEM-135 allele in Shandong has a dynamically changing status. Therefore, it is very pressing to continuously monitor the prevalence and mutation of the blaTEM-135 allele and the genetic epidemiology of PPNG isolates carrying the blaTEM-135 allele in this district.

In Vitro Activity of Ertapenem against Neisseria gonorrhoeae Clinical Isolates with Decreased Susceptibility or Resistance to Extended-Spectrum Cephalosporins in Nanjing, China (2013 to 2019)

Neisseria gonorrhoeae isolates collected in Nanjing, China, that possessed decreased susceptibility (or resistance) to extended-spectrum cephalosporins (ESCs) were examined for susceptibility to ertapenem, and their sequence types were determined. Ceftriaxone and cefixime MICs of ≥0.125 mg/L and ≥0.25 mg/L, respectively, were first determined in 259 strains isolated between 2013 and 2019, and then MICs of ertapenem were measured using the antimicrobial gradient Epsilometer test (Etest). Also, genetic determinants of ESC resistance were identified and N. gonorrhoeae multiantigen sequence typing (NG-MAST) was performed to analyze associations with ertapenem susceptibility. All isolates displayed ertapenem MICs between 0.006 mg/L and 0.38 mg/L; the overall MIC₅₀ and MIC₉₀ were 0.032 mg/L and 0.125 mg/L, respectively. Forty-four (17.0%) isolates displayed ertapenem MICs of ≥0.125 mg/L; 10 (3.9%) had MICs of ≥0.25 mg/L. The proportion of isolates with ertapenem MICs of ≥0.125 mg/L increased from 4.0% in 2013 to 20.0% in 2019 (χ² = 24.144, P < 0.001; chi-square test for linear trend). The penA mosaic allele was present in a significantly higher proportion of isolates with ertapenem MICs of ≥0.125 mg/L than of isolates with MICs of ≤0.094 mg/L) (97.7% versus 34.9%, respectively; χ² = 58.158, P < 0.001). ST5308 was the most prevalent NG-MAST type (8.5%); ST5308 was also significantly more common among isolates with ertapenem MICs of ≥0.125 mg/L than isolates with MICs of ≤0.094 mg/L (22.7% and 5.6%, respectively; χ² = 13.815, P = 0.001). Ertapenem may be effective therapy for gonococcal isolates with decreased susceptibility or resistance to ESCs and isolates with identifiable genetic resistance determinants.

Correlates of time to clinical presentation for symptomatic individuals with gonorrhoea in South China: results from a cross-sectional study

OBJECTIVES

This study aimed to determine the variation in the interval between the onset of symptoms and clinical presentation, and its associated factors among symptomatic individuals with gonorrhoea.

DESIGN

A cross-sectional study was conducted between 1 June and 30 July 2017.

SETTING

129 sexually transmitted disease clinics from 21 cities of Guangdong, China.

PARTICIPANTS

Using convenience sampling method to recruit symptomatic individuals with gonorrhoea over 18 years old.

OUTCOME MEASURE

Time to clinical presentation.

RESULTS

Among 1664 participants, the median age was 29 (24-36) years old, and the majority were male (92.5%) and married (52.9%). The median time to clinical presentation was 3 (2-6) days. About 471 (28.3%) patients had sexual contact while symptomatic. After adjusting for covariates, participants who were female (aβ=0.44, 95% CI: 0.22 to 0.80), from east Guangdong region (aβ=0.44, 95% CI: 0.22 to 0.80) and had the absence of dysuria (aβ=0.26, 95% CI: 0.06 to 0.46) had increased time to clinical presentation. Participants who had commercial sex in the past 6 months (aβ=-0.11, 95% CI: -0.21 to -0.01) had decreased time to clinical presentation. Participants who were female (adjusted odds ratio (aOR)=1.66, 95% CI: 1.08 to 2.50) and delayed in seeking healthcare more than 7 days (aOR=46.71, 95% CI: 24.27 to 89.93) were more likely to have sexual contact while symptomatic.

CONCLUSION

The time to clinical presentation for individuals with symptomatic gonorrhoea is variable and a high proportion of participants continued to have sexual behaviour while symptomatic. Strategies to increase health literacy may help to minimise the sequelae of gonorrhoea and reduce onward transmission.

Dissemination and genome analysis of high-level ceftriaxone-resistant penA 60.001 Neisseria gonorrhoeae strains from the Guangdong Gonococcal Antibiotics Susceptibility Programme (GD-GASP), 2016-2019

Background: After Neisseria gonorrhoeae FC428 was first found in Japan, ceftriaxone-resistant strains disseminated globally, and the gonococcal resistance rate increased remarkably. Epidemiological investigations are greatly significant for the analysis of antimicrobial resistance (AMR) trends, molecular features and evolution. Objectives: To clarify the AMR trend from 2016–2019 and reveal the molecular characteristics and evolution of ceftriaxone-resistant penA 60.001 isolates. Methods: The minimum inhibitory concentrations (MICs) of antibiotics against 4113 isolates were detected by the agar dilution method. N. gonorrhoeae multiantigen sequence typing (NG-MAST), multilocus sequence typing (MLST) and N.gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) were used to identify the sequence types. Genome analysis was conducted to analyze resistance genes, virulence factors, and evolutionary sources. Results: Isolates with decreased ceftriaxone susceptibility have increased from 2.05% (2016) to 16.18% (2019). Six ceftriaxone-resistant isolates possessing penA 60.001 appeared in Guangdong Province, and were resistant to ceftriaxone, penicillin, tetracycline, ciprofloxacin and cefixime, but susceptible to azithromycin and spectinomycin. Single-nucleotide polymorphisms (SNPs) in the porB gene were the major cause of different NG-MAST types. ST1903 was the main NG-STAR genotype and only strain-ZH545 was ST7365, with molecular features consistent with the MICs. Furthermore, different MLSTs suggested diverse evolutionary sources. Genome analysis revealed a set of virulence factors along with the resistance genes “penA” and “blaTEM-1B”. Half of penA 60.001 strains were fully mixed with global FC428-related strains. Conclusions: Global FC428-related clones have disseminated across Guangdong, possibly causing decreased ceftriaxone susceptibility. Enhanced gonococcal surveillance will help elucidate the trajectory of transmission and curb further dissemination.

Four Types of ST11 Novel Mutations From Increasing Carbapenem-Resistant Klebsiella pneumoniae in Guangdong, 2016-2020

Objectives: This study aimed to explore changes in carbapenem-resistant Klebsiella pneumoniae (CR-KP) isolates collected in Guangdong over the period of 2016–2020.

Methods: Antibacterial susceptibility was quantified through VITEK 2 compact and K-B method. Carbapenemase phenotypes and genotypes were characterized by modified carbapenem inactivation method (mCIM), EDTA-carbapenem inactivation method (eCIM), and polymerase chain reaction (PCR). Molecular characteristics and evolutionary trends were analyzed by multilocus sequence typing and evolutionary tree.

Results: Isolates (2,847) of K. pneumoniae were separated in 2016–2020, and the separate rate of CR-KP increased from 5.65 to 9.90% (p = 0.009). The top 3 wards were intensive care unit (ICU) (21.92%), neonatal wards (13.70%), and respiratory wards (12.33%). In 146 CR-KP strains, serine carbapenemase was the main phenotype, and KPC was the main genotype, and 57 contained two resistant genes, and 1 contained three resistant genes. Two polygenic strains were first found: IMP + GES and KPC + NDM + VIM, but all the phenotypes were metalloenzyme, which indicated that metalloenzyme was usually the first choice for CR-KP resistance. In addition, all the ST54 of metalloenzyme type contained IMP, and all the ST45, ST37, and ST76 contained OXA. ST11 was the most prevalent (42.47%); ST11 and its mutants proved the predominant sequence type making up 51.1% of the carbapenemase-producing isolates. A novel type of ST11 mutation, the rpoB was mutated from sequence 1 to sequence 146, was in an independent separate branch on the evolutionary tree and was resistant to all antibacterial agents. The other three mutants, rpoB 1–15, infB 3–148, and infB 3–80, are also resistant to all antibacteria. Of note, all the four mutants produced serine carbapenemase and contained KPC, and indicated that the prevalent strain in China, ST11, has serious consequences and potential outbreaks.

Conclusion: The infection rate of CR-KP has increased, and ICU and neonatal wards have become the key infection areas. Producing serine enzyme, the KPC genotype, and ST11 are the predominant CR-KP. Polygenic strains and ST11 mutation made clinical treatment difficult and may become a potential threat.

The Accuracy of Molecular Detection Targeting the Mutation C2611T for Detecting Moderate-Level Azithromycin Resistance in Neisseria gonorrhoeae: A Systematic Review and Meta-Analysis

BACKGROUND

Neisseria gonorrhoeae (N. gonorrhoeae) is now recognized as a commonly reported sexually transmitted pathogen, and the increasing drug resistance of N. gonorrhoeae has become a serious public health problem. The accuracy of molecular detection for detecting moderate-level azithromycin resistance is not well-established. We summarized the data from studies of the N. gonorrhoeae 23S rRNA mutation at position 2611 with azithromycin resistance to determine the relationship between the mutation and resistance.

METHODS AND FINDINGS

In this systematic review and meta-analysis, two researchers independently searched six databases for studies with data for the azithromycin minimum inhibitory concentrations (MICs) and the 23S rRNA mutation C2611T of each N. gonorrhoeae isolate. Since the breakpoint of moderate-level resistance to azithromycin (ML-AzmR) was not determined, we divided the moderate level into two groups according to the range of MICs (moderate resistance limited to 2-128 mg/L or 4-128 mg/L) for data extraction. A random-effects model was used to calculate the pooled sensitivity rate, the specificity rate, the pooled positive likelihood ratio (PLR), the negative likelihood ratio (NLR), and the diagnostic odds ratio (DOR). Meta-regression analyses by detection method, isolates sampling (a random sample or not), location, and sample size were performed to explore the possible causes of heterogeneity. The potential publication bias of the included studies was conducted by the Deeks' test. We included 20 studies in our study: 20 studies have data of N. gonorrhoeae with MICs between 2 and 128 mg/L with mutation or without mutation at position 2611(4759 samples), and 14 studies have data of N. gonorrhoeae with MICs between 4 and 128 mg/L (3367 samples). In the group with the moderate level of 2-128 mg/L, the pooled sensitivity rate of the molecular assays was determined to be 71.9% (95% CI, 67.6-74%), the pooled specificity rate was 98.7% (95% CI, 98.2-99.0%), and the DOR ranged from 55.0 to 351.3 (mean, 139.1). In the 4-128 mg/L group, the pooled sensitivity rate was 91.9% (95% CI, 88.9-94.2%), the pooled specificity rate was 95.9% (95% CI, 95.1-96.6%), and the DOR ranged from 41.9 to 364.1 (mean, 123.6).

CONCLUSION

Through this meta-analysis, we found that the C2611T mutation of 23S rRNA is valuable for the molecular diagnostic of moderate-level azithromycin resistance (ML-AzmR) in N. gonorrhoeae, especially when the moderate level is set at 4-128 mg/L. This rapid molecular detection method can be used for the rapid identification of ML-AzmR isolates in the clinic.