Neisseria gonorrhoeae Multiantigen Sequence Typing Is Beneficial in Further Characterizing Gonococcal Populations in Alberta, Canada

Neisseria gonorrhoeae treatment failure to the recommended antibiotic regimen-Québec, Canada, 2015-19

OBJECTIVE

To describe Neisseria gonorrhoeae treatment failure to the recommended antimicrobial regimens (azithromycin, cefixime and ceftriaxone).

METHODS

Our study was a longitudinal analysis of treatment failures from an observational open cohort of gonococcal infection cases collected in Québec, Canada (n = 2547) between September 2015 and December 2019. Epidemiological and clinical data were collected using a self-administered questionnaire, direct case interviews and chart reviews. Antimicrobial susceptibility testing was performed using the agar dilution method. To be retained as a treatment failure, cases must have had (i) a laboratory-confirmed gonococcal infection; (ii) a documented treatment; (iii) a positive test of cure (TOC) performed within a defined period and (iv) no sexual contact (vaginal, oral or anal), even protected with a condom, between the beginning of treatment and the positive TOC. A broader definition, including suspected cases, was also examined.

RESULTS

Among 1593 cases where a TOC was performed, 83 had a positive TOC: 11 were retained as treatment failure, and 6 were considered suspected cases (overall = 17/1593; 1.1%). Possible explanations for retained or suspected treatment failure included resistance to the antibiotics used for treatment (n = 1), pharyngeal infection (n = 9, of which 5 had been treated with ceftriaxone and 4 with other regimens); and azithromycin monotherapy (n = 1). Some cases had more than one potential explanation.

CONCLUSIONS

Treatment failure occurred in 1.1% of cases of Neisseria gonorrhoeae infection for which a TOC was performed, including some cases of pharyngeal infection treated with ceftriaxone.

Antimicrobial resistance and heterogeneity of Neisseria gonorrhoeae isolated from patients attending sexually transmitted infection clinics in Lusaka, Zambia

BACKGROUND

Antimicrobial resistance (AMR) of Neisseria gonorrhoeae is a threat to public health as strains have developed resistance to antimicrobials available for the treatment of gonorrhea. Whole genome sequencing (WGS) can detect and predict antimicrobial resistance to enhance the control and prevention of gonorrhea. Data on the molecular epidemiology of N. gonorrhoeae is sparse in Zambia. This study aimed to determine the genetic diversity of N. gonorrhoeae isolated from patients attending sexually transmitted infection (STI) clinics in Lusaka, Zambia.

METHODS

A cross-sectional study that sequenced 38 N. gonorrhoeae isolated from 122 patients with gonorrhea from 2019 to 2020 was conducted. The AMR profiles were determined by the E-test, and the DNA was extracted using the NucliSens easyMaG magnetic device. Whole genome sequencing was performed on the Illumina NextSeq550 platform. The Bacterial analysis pipeline (BAP) that is readily available at: https://cge.cbs.dtu.dk/services/CGEpipeline-1.1 was used for the identification of the species, assembling the genome, multi-locus sequence typing (MLST), detection of plasmids and AMR genes. Phylogeny by single nucleotide polymorphisms (SNPs) was determined with the CCphylo dataset.

RESULTS

The most frequent STs with 18.4% of isolates each were ST7363, ST1921 and ST1582, followed by ST1583 (13%), novel ST17026 (7.9%), ST1588 (7.9%), ST1596 (5.3%), ST11181 (5.3%), ST11750 (2.6/%) and ST11241 (2.6%) among the 38 genotyped isolates. The blaTeM-1B and tetM (55%) was the most prevalent combination of AMR genes, followed by blaTeM-1B (18.4%), tetM (15.8%), and the combination of blaTeM-1B, ermT, and tetL was 2.6% of the isolates. The AMR phenotypes were predicted in ciprofloxacin, penicillin, tetracycline, azithromycin, and cefixime. The combination of mutations 23.7% was gryA (S91F), parC (E91G), ponA (L421) and rpsJ (V57M), followed by 18.4% in gyrA (S91F), ponA (L421P), rpsJ (V57M), and 18.4% in gyrA (D95G, S91F), ponA (L421P), and rpsJ (V57M). The combinations in gyrA (D95G, S91F) and rpsJ (V57M), and gyrA (D95G, S91F), parC (E91F), ponA (L421P) and rpsJ (V57M) were 13.2% each of the isolates. Plasmid TEM-1 (84.2%), tetM (15.8%), and gonococcal genetic island (GGI) was detected in all isolates.

CONCLUSION

This study revealed remarkable heterogeneity of N. gonorrhoeae with blaTEM-1, tetM, ponA, gyrA, and parC genes associated with high resistance to penicillin, tetracycline, and ciprofloxacin demanding revision of the standard treatment guidelines and improved antimicrobial stewardship in Zambia.

Dimensions of poverty as risk factors for antimicrobial resistant organisms in Canada: a structured narrative review

Background

Few studies have assessed the relationship between poverty and the risk of infection with antimicrobial resistant organisms (AROs). We sought to identify, appraise, and synthesize the available published Canadian literature that analyzes living in poverty and risk of AROs.

Methods

A structured narrative review methodology was used, including a systematic search of three databases: MedLINE, EMBASE and Web of Science for articles pertaining to poverty, and infection with AROs in Canada between 1990 and 2020. Poverty was broadly defined to include economic measures and associated social determinants of health. Based on inclusion and exclusion criteria, there were 889 initial articles, and 43 included in the final review. The final articles were extracted using a standard format and appraised using the Joanna Briggs Institute Levels of Evidence framework.

Results

Of 43 studies, 15 (35%) related to methicillin-resistant Staphylococcus aureus (MRSA). One study found a 73% risk reduction (RR 0.27, 95%CI 0.19–0.39, p =  < 0.0001) in community-acquired MRSA (CA-MRSA) infection for each $100,000 income increase. Results pertaining to homelessness and MRSA suggested transmission was related to patterns of frequent drug use, skin-to-skin contact and sexual contact more than shelter contact. Indigenous persons have high rates of CA-MRSA, with more rooms in the house being a significant protective factor (OR 0.86, p = 0.023). One study found household income over $60,000 (OR 0.83, p = 0.039) in univariate analysis and higher maternal education (OR 0.76, 95%CI 0.63–0.92, p = 0.005) in multivariate analysis were protective for otitis media due to an ARO among children. Twenty of 43 (46.5%) articles pertained to tuberculosis (TB). Foreign-born persons were four times more likely to have resistant TB compared to Canadian-born persons. None of the 20 studies used income in their analyses.

Conclusions

There is an association between higher income and protection from CA-MRSA. Mixed results exist regarding the impact of homelessness and MRSA, demonstrating a nuanced relationship with behavioural risk factors. Higher income and maternal education were associated with reduced ARO-associated acute otitis media in children in one study. We do not have a robust understanding of the social measures of marginalization related to being foreign-born that contribute to higher rates of resistant TB infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-022-01059-1.

Molecular epidemiology of penicillinase-producing <i>Neisseria gonorrhoeae</i> isolates and their <i>bla</i>_TEM-135 gene variant in Bangkok, Thailand, 2015–2017

Penicillinase-producing Neisseria gonorrhoeae (PPNG) possessing bla_TEM-135 is a serious public health threat. With only a single change in the amino acid sequence, bla_TEM-135 could evolve into a TEM-type extended-spectrum beta-lactamase (ESBL), which hydrolyzes extended-spectrum cephalosporins, including ceftriaxone and cefixime. We investigated the molecular epidemiological characteristics, types of plasmids in PPNG isolates, and prevalence of PPNG clinical isolates producing TEM-135 beta-lactamases. N. gonorrhoeae multi-antigen sequence typing (NG-MAST) was used to determine the molecular epidemiological characteristics of 99 PPNG isolates collected from 2015 to 2017. A mismatch amplification mutation assay was used to examine the bla_TEM-135 gene prevalence. Of the 89 identified NG-MAST sequence types, 65 (73.0%) were novel. Only 17.7% (43/243) of PPNG isolates belonged to 16 genogroups. The most frequent plasmid was African, followed by Rio/Toronto, and Asian. The bla_TEM-135 allele was found in Rio/Toronto plasmids. The bla_TEM-135 allele was present in 23.2% (23/99) of the PPNG isolates. PPNG isolates expressing TEM-135 beta-lactamase exhibited significantly higher penicillin MIC (minimum inhibitory concentration) values than TEM-1 PPNG isolates. The PPNG isolates showed high genetic diversity and a high proportion of bla_TEM-135 alleles. Mutation of the bla_TEM-135 allele is worrisome as only one mutation could cause TEM-1 to evolve into an ESBL variant that degrades ceftriaxone. Ongoing surveillance of bla_TEM-135 and new PPNG isolates is imperative.

Molecular Surveillance and Prediction of Antimicrobial Resistance of Neisseria gonorrhoeae in Northern Alberta, Canada, 2015 to 2018

BACKGROUND

The aims of this study was to describe molecular surveillance of Neisseria gonorrhoeae in the North Zone of Alberta (NZ) and to determine its value in predicting antimicrobial resistance.

METHODS

Sequence types (STs) and single-nucleotide polymorphism (SNP) assays were performed on nucleic acid amplification testing (NAAT) samples. Sequence types of NAATs were matched to ST of cultures from across Alberta. Antimicrobial resistance prediction of NAATs for cephalosporins, azithromycin, and ciprofloxacin using SNP was compared with matching ST culture results using agar dilution and whole-genome sequencing.

RESULTS

Of 2755 eligible specimens (2492 cases), 61.9% (1646 specimens) were sent for sequence typing, identifying 196 unique ST. Antimicrobial resistance data for 1307 additional cases were available using matching cultures. Decreased susceptibility (DS) to antimicrobials used for gonorrhea treatment was rare in the NZ; according to the SNP assay, none of the specimens had predicted DS to cephalosporins or azithromycin resistance. However, of the NZ NAAT samples tested in this study, 10.7% (131 of 1220) were predicted to have intermediate cephalosporin minimum inhibitory concentrations and 9.6% (115 of 1204) were resistant to ciprofloxacin. Based on cultures, the proportions of resistance in all of Alberta were as follows: DS to cephalosporins, 0.6% (20 of 3373); DS to intermediate cephalosporin, 16.9% (570 of 3373); azithromycin resistance, 1.2% (41 of 3373); and ciprofloxacin resistance, 32.2% (1087 of 3373).

CONCLUSIONS

Our results highlight our ability to use culture-independent methods to predict antimicrobial resistance in N. gonorrhoeae.

Increase in Gonorrhea Incidence Associated With Enhanced Partner Notification Strategy

OBJECTIVES

Partner notification services for reportable sexually transmitted infections vary based on jurisdiction, resources, type of infection, and whether an outbreak has been reported. The objective of this study was to determine whether case finding increased after implementation of enhanced notification and follow-up activities for contacts of cases of Neisseria gonorrhoeae in Central Zone, the largest health authority in Nova Scotia, Canada.

METHODS

Enhanced contact tracing by public health professionals was implemented in May 2015. N. gonorrhoeae multiantigen sequence typing (NG-MAST) was conducted on all positive specimens. Epidemiologic and NG-MAST information for reported gonorrhea cases were captured and analyzed. Case numbers, rates, and NG-MAST results in the preintervention and postintervention periods were compared. Laboratory testing data were extracted and analyzed for association with reported incidence.

RESULTS

There was a significant increase in the number of reported gonorrhea cases per month when comparing the preintervention and postintervention periods. The reported gonorrhea rate in 2016 was 2.9 times that in 2014. This increase was not associated with changes in testing rates and was more pronounced among women than men. Larger groups of cases sharing the same NG-MAST profiles were detected postintervention.

CONCLUSIONS

The implementation of an enhanced contact tracing program for N. gonorrhoeae resulted in increased case finding and a notable increase in the reported rate of cases per 100,000 population. Owing to these findings, the practice of enhanced partner notification was continued as standard public health practice in Central Zone. An understanding of case finding efforts is required when interpreting observed trends in rates of N. gonorrhoeae, as early infection is highly asymptomatic in women and can be asymptomatic in men.

Antimicrobial resistance (AMR) and molecular characterization of Neisseria gonorrhoeae in Ghana, 2012-2015

Neisseria gonorrhoeae antimicrobial resistance (AMR) surveillance is essential for tracking the emergence and spread of AMR strains in local, national and international populations. This is crucial for developing or refining treatment guidelines. N. gonorrhoeae multiantigen sequence typing (NG-MAST) is beneficial for describing the molecular epidemiology of gonococci at national and international levels. Elucidation of AMR determinants to β-lactam drugs, is a means of monitoring the development of resistance. In Ghana, little is known about the current gonococcal AMR prevalence and no characterization of gonococcal isolates has been previously performed. In this study, gonococcal isolates (n = 44) collected from five health facilities in Ghana from 2012 to 2015, were examined using AMR testing, NG-MAST and sequencing of penA. High rates of resistance were identified to tetracycline (100%), benzylpenicillin (90.9%), and ciprofloxacin (81.8%). One isolate had a high cefixime MIC (0.75 μg/ml). Twenty-eight NG-MAST sequence types (STs) were identified, seventeen of which were novel. The isolate with the high cefixime MIC contained a mosaic penA-34 allele and belonged to NG-MAST ST1407, an internationally spreading multidrug-resistant clone that has accounted for most cefixime resistance in many countries. In conclusion, AMR testing, NG-MAST, and sequencing of the AMR determinant penA, revealed high rates of resistance to tetracycline, benzylpenicillin, and ciprofloxacin; as well as a highly diverse population of N. gonorrhoeae in Ghana. It is imperative to continue with enhanced AMR surveillance and to understand the molecular epidemiology of gonococcal strains circulating in Ghana and other African countries.

Surveillance for Antimicrobial Resistance in Gonorrhea: The Alberta Model, 2012⁻2016

Alberta established a surveillance system in 2001 to monitor resistance to antibiotics used for the treatment of gonorrhea. A retrospective review of gonorrhea cases during the last five years was conducted. All cases of gonorrhea were reportable to public health by testing laboratories and clinicians. Specimens were primarily submitted for nucleic acid amplification testing (NAAT); three sentinel sites obtained specimens for culture and NAAT. The Provincial Laboratory for Public Health conducted E-tests on isolates for multiple antibiotics. A proportion of isolates and NAAT specimens were submitted to the National Microbiology Laboratory for sequence typing (ST). Data were combined and analyzed using SAS version 9.4. Between 2012 and 2016, 13,132 gonorrhea cases were reported; 22.0% (n = 2891) had isolates available for susceptibility testing. All culture positive isolates were susceptible to ceftriaxone. Decreased susceptibility (0.5 ug/mL) to cefixime was reported in four cases in 2014. Resistance to azithromycin (≥2 ug/mL) ranged between 0.4% and 1.8%. Many (n = 509) unique STs were identified; the most prevalent sequence groups (SG) were SG-7638 (n = 367), SG-5985 (n = 145), and SG-11299 (n = 127). The Alberta model for maintaining surveillance for antimicrobial resistance in gonorrhea employs culture and NAAT specimens, providing information crucial to informing provincial treatment guidelines.

Neisseria gonorrhoeae molecular typing for understanding sexual networks and antimicrobial resistance transmission: A systematic review

•

Combined molecular and epidemiological data can describe the spread of gonorrhoea.

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Sexual networks can be inferred from molecular clusters of infection.

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Gender and sexual orientation are commonly used to characterise these networks.

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Application of these data within gonorrhoea control interventions is limited.

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Future studies should focus on evaluating molecular typing data in practice.

Objectives

Neisseria gonorrhoeae (NG) is a significant global public health concern due to rising diagnoses rates and antimicrobial resistance. Molecular combined with epidemiological data have been used to understand the distribution and spread of NG, as well as relationships between cases in sexual networks, but the public health value gained from these studies is unclear. We conducted a systematic review to examine how molecular epidemiological studies have informed understanding of sexual networks and NG transmission, and subsequent public health interventions.

Methods

Five research databases were systematically searched up to 31st March 2017 for studies that used sequence-based DNA typing methods, including whole genome sequencing, and linked molecular data to patient-level epidemiological data. Data were extracted and summarised to identify common themes.

Results

Of the 49 studies included, 82% used NG Multi-antigen Sequence Typing. Gender and sexual orientation were commonly used to characterise sexual networks that were inferred using molecular clusters; clusters predominantly of one patient group often contained a small number of isolates from other patient groups. Suggested public health applications included using these data to target interventions at specific populations, confirm outbreaks, and inform partner management, but these were mainly untested.

Conclusions

Combining molecular and epidemiological data has provided insight into sexual mixing patterns, and dissemination of NG, but few studies have applied these findings to design or evaluate public health interventions. Future studies should focus on the application of molecular epidemiology in public health practice to provide evidence for how to prevent and control NG.

Gonorrhea in Canada, 2010-2015

Background

Gonorrhea is the second most commonly reported sexually transmitted infection (STI) in Canada after chlamydia, and rates for this STI have been increasing since 1997.

Objective

To summarize trends observed in gonorrhea rates for 2010-2015 in Canada.

Methods

Laboratory-confirmed cases of gonorrhea are reported to the Public Health Agency of Canada (PHAC) by all of the Canadian provinces and territories. The overall national rate was computed, as were rates per sex, age group and province/territory.

Results

In 2015, 19,845 cases of gonorrhea were reported in Canada, corresponding to a rate of 55.4 cases per 100,000 population and a 65.4% increase from 2010 (33.5 cases per 100,000 population). Males had consistently higher rates than did females (70.2 per 100,000 versus 40.6 per 100,000 in 2015) and faster rising rates (85.2% versus 39.5% in 2010-2015). Rates among adults 60 years and older increased faster than rates among younger people, although the highest rates were among those 15-29 years of age. The Northwest Territories, Nunavut and Yukon had the highest gonorrhea rates in 2015.

Conclusion

Males, adolescents and young adults continue to represent the majority of gonorrhea cases. Research is needed to better understand the current trends in gonorrhea infection in order to maintain, evaluate and improve primary and secondary STI prevention activities.

Antimicrobial Resistance and Neisseria gonorrhoeae Multiantigen Sequence Typing Profile of Neisseria gonorrhoeae in New Delhi, India

Molecular epidemiology of 100 consecutive gonococcal isolates collected between April 2010 and October 2013 from New Delhi was investigated using Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST) along with its association with antimicrobial resistance profiles. Neisseria gonorrhoeae isolates were assigned into 60 different sequence types and 43 (71.6%) were novel. Sole representation was seen in 76.6% sequence types. There was significant association between ST6058 and resistance to penicillin (P = 0.00) and tetracycline (P = 0.002).

Molecular epidemiology and mechanisms of resistance of azithromycin-resistant Neisseria gonorrhoeae isolated in France during 2013-14

OBJECTIVES

The objective of this study was to determine the prevalence and mechanisms of azithromycin resistance of Neisseria gonorrhoeae French isolates from 2013 to 2014.

METHODS

N. gonorrhoeae samples isolated in a network of laboratories were tested for susceptibility to azithromycin between April 2013 and March 2014. Fifty-four isolates that were non-susceptible to azithromycin and 18 susceptible isolates were characterized for molecular mechanisms of resistance by PCR/sequencing and genotyped using N. gonorrhoeae multiantigen sequence typing (NG-MAST).

RESULTS

Among the 970 N. gonorrhoeae isolates, 54 (5.56%) were non-susceptible to azithromycin, 9 (1%) were resistant and 45 (4.6%) showed intermediate resistance. Azithromycin-non-susceptible isolates harboured a C2599T mutation in the rrl gene encoding the 23S rRNA alleles (5.5%), a C substitution in the mtrR promoter (5.5%), an A deletion in the mtrR promoter (53.7%) and mutations in the L4 ribosomal protein (14.8%) and in the MtrR repressor (25.9%). No isolates showed an L22 mutation or carried an erm, ere, mef(A)/(E) or mphA gene. Thirty different STs were highlighted using the NG-MAST technique. The predominant genogroups non-susceptible to azithromycin were G21 (31%), G1407 (20%) and G2400 (15%). Genogroup G2400 (15%) was revealed to be a novel cluster prevalent in the south of France and resistant to azithromycin, ciprofloxacin and tetracycline.

CONCLUSIONS

Our study highlights that the prevalence of resistance of N. gonorrhoeae to azithromycin in France is low and essentially due to multiple genetic mutations. Its dissemination occurs through three major genogroups including a novel one in France (G2400).

Gonorrhea Treatment Failures With Oral and Injectable Expanded Spectrum Cephalosporin Monotherapy vs Dual Therapy at 4 Canadian Sexually Transmitted Infection Clinics, 2010-2013

BACKGROUND

Antimicrobial resistance has developed to all antibiotics used to treat gonorrhea (GC), and trends in GC antimicrobial resistance have prompted changes in treatment guidelines. We examined treatment failures in sexually transmitted infection clinics.

METHODS

Four Canadian sexually transmitted infection clinics reviewed treatment regimens, minimum inhibitory concentrations for cephalosporins and azithromycin, anatomical infection sites, and treatment outcomes for GC infections between January 2010 and September 2013, in individuals who returned for test of cure within 30 days of treatment. Treatment failure was defined as the absence of reported sexual contact during the posttreatment period and (i) positive for Neisseria gonorrhoeae on culture of specimens taken at least 72 hours after treatment or (ii) positive nucleic acid amplification test specimens taken at least 2 to 3 weeks after treatment, and matching sequence type pretreatment and posttreatment. χ Test and Fisher exact test were used to assess association of categorical variables.

RESULTS

Of 389 specimens reviewed, GC treatment failures occurred in 13 specimens treated with cefixime 400-mg single dose (17.8% treatment failure rate regardless of anatomical site) and in 1 oropharyngeal specimen treated with cefixime 800-mg single dose. No treatment failures occurred using either ceftriaxone monotherapy or cefixime/ceftriaxone combined with azithromycin or doxycycline.

CONCLUSIONS

In contrast to oral cefixime monotherapy, no treatment failures were identified with injectable ceftriaxone monotherapy or combination GC treatment. Our data support the use of combination treatment of GC with an extended spectrum cephalosporin (including oral cefixime) with azithromycin or doxycycline as well as ceftriaxone monotherapy.

Molecular epidemiology of Neisseria gonorrhoeae isolates from Saskatchewan, Canada: utility of NG-MAST in predicting antimicrobial susceptibility regionally

OBJECTIVES

To investigate the molecular epidemiology of isolates of Neisseria gonorrhoeae from Saskatchewan, Canada, using Neisseria gonorrhoeae multi antigen sequence typing (NG-MAST), and to assess associations between antimicrobial susceptibility (AMS) and specific strain types (STs).

METHODS

320 consecutive gonococcal isolates, collected between 2003 and 2008, were typed by NG-MAST. STs were grouped if one of their alleles was common and the other differed by ≤1% in DNA sequence. AMS was determined by agar dilution (CLSI) to seven antibiotics.

RESULTS

N gonorrhoeae isolates were resolved into 82 individual NG-MAST STs and 18 NG-MAST ST groups with groups 25, 3655, 921, 3654, 3657 and 3656 comprising 53.4% (171/320) of the isolates. N gonorrhoeae isolates susceptible to all the tested antimicrobials were significantly (p<0.05) associated with ST 25 (87%). Other significant associations between ST and AMS included: ST 3654 and isolates with minimum inhibitory concentrations of ≥0.03 mg/L to third generation cephalosporins; ST 3711 (100%) and TRNG; and ST/group 3654 (43%) and chromosomal resistance to penicillin and tetracycline. Several NG-MAST STs/groups were significantly associated with isolates with chromosomal resistance to tetracycline. Isolates resistant to ciprofloxacin (n=5) and azithromycin (n=2) appeared as individual STs. Significant associations were observed among individual STs, sex and age of the patient, and regional and temporal distributions.

CONCLUSIONS

Associations between N gonorrhoeae AMS and NG-MAST STs were identified and may be useful in predicting AMS regionally. Because STs in different countries vary considerably, the use of NG-MAST for the prediction of AMS globally requires further study.