Susceptibility of gonococci isolated in London to therapeutic antibiotics: establishment of a London surveillance programme. London Gonococcal Working Group

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.

Antimicrobial Susceptibility Testing Patterns of Neisseria gonorrhoeae from Patients Attending Sexually Transmitted Infections Clinics in Six Regions in Tanzania

Antimicrobial resistance (AMR) is global health threat that is on the increase, and it has been adversely affecting the proper management of sexually transmitted infections (STI). Data on antimicrobial susceptibility testing patterns of N. gonorrhoeae are limited in local settings. We determined in vitro antimicrobial susceptibility and phenotypic profiles of N. gonorrhoeae isolated from STI/Outpatient Department (OPD) clinics. Minimum Inhibitory Concentrations (MIC) (µg/mL) were determined using E-Test and agar dilution methods for previously and currently recommended antimicrobial agents. A total of 164 N. gonorrhoeae isolates from urethral discharge and endocervical swabs were tested. The prevalence of resistant N. gonorrhoeae to tetracycline, norfloxacin, penicillin and ciprofloxacin were 98.6%, 82.2%, 84.3% and 75.6%, respectively. None of the isolates was resistant to kanamycin. Penicillinase producing N. gonorrhoeae (PPNG) was found to be 73.7%, with 56.7% and 43.3% observed among isolates from women and men, respectively. Tetracycline resistant-N. gonorrhoeae (TRNG) was found to be 34.0%, and QRNG with HLR to ciprofloxacin was 79.9%. The overall MDR-NG was 79.9%, and XDR-NG was 3.6%. MIC50 and MIC90 were 4.0 and 8.0 and 2.0 and 4.0 µg/mL for ciprofloxacin and norfloxacin, respectively. Dendrograms showed that 44 phenotypic groups are associated with a high rate of AMR among high MDR-NG and moderate XDR-NG isolates. The predominant groups of quinolone-resistant N. gonorrhoeae (QRNG)+PPNG (34.7%) and QRNG+PPNG+TRNG (32.9%) were observed among the isolates having HLR to ciprofloxacin. We reported a high prevalence of AMR (>90%) to previously recommended antimicrobials used for the treatment of gonorrhoea. Multidrug resistant N. gonorrhoeae (MDR-NG) was highly reported, and extensively drug resistant (XDR-NG) has gradually increased to the currently recommended cephalosporins including ceftriaxone and cefixime. Heterogeneous groups of QRNG+PPNG+ and QRNG+PPNG+TRNG were highly resistant to penicillin, tetracycline, ciprofloxacin and norfloxacin. A surveillance program is imperative in the country to curb the spread of AMR.

Identification of individuals with gonorrhoea within sexual networks: a population-based study

BACKGROUND

Molecular typing of Neisseria gonorrhoeae and contact tracing provide a combined approach for analysis of sexual networks in metropolitan areas, although there are some difficulties in application. Our aim was to examine the application of high-throughput molecular approaches that can identify individuals in linked sexual networks.

METHODS

We characterised 2045 isolates of N gonorrhoeae from patients presenting at 13 major sexually transmitted infection clinics in London, UK, between June 1 and Nov 30, 2004. All isolates were assigned a sequence type (strain) on the basis of the sequences of internal fragments of two highly polymorphic loci, por and tbpB. These types were matched to demographic and behavioural data obtained at the clinic for each patient. We assessed the congruence in the demographic and behavioural characteristics of individuals infected with the same strain.

FINDINGS

We identified 21 prevalent strains in this diverse gonococcal population, each infecting between 20 and 124 individuals. Seven of these strains were predominantly from men who have sex with men; the remaining 14 were predominantly from heterosexual people. No differences were recorded between the strains associated with men who have sex with men in the demographic or behavioural characteristics of infected individuals. By contrast, significant differences in age (p<0.0001), ethnicity (p=0.001), proportion of women (p=0.01), and HIV status (p=0.03) were noted between the 14 prevalent heterosexual-associated strains. Heterosexuals with strains not shared by others in the sample were significantly older (p=0.0005) and more likely to have had sex outside the UK (p<0.0001) than those sharing a strain with at least one other.

INTERPRETATION

The discriminatory high throughput strain characterisation method applied here identified localised transmission networks and suggests little bridging between networks of men who have sex with men and heterosexual networks.

Laboratory diagnosis of Neisseria gonorrhoeae in St Petersburg, Russia: inventory, performance characteristics and recommended optimisations

OBJECTIVES

To perform a comprehensive inventory of the number of samples, performance characteristics, and quality assurance of the laboratory diagnosis of Neisseria gonorrhoeae at five laboratories in St Petersburg and Leningradskaya Oblast, Russia, in 2004, and to recommend optimisations for an increased adherence to international evidence based recommendations of diagnostics.

METHODS

Surveillance data were obtained with questionnaire and site visits. For evaluation of the culture media utilised at the laboratories, N gonorrhoeae reference strains (n = 29) were used.

RESULTS

During 2004 the total numbers of N gonorrhoeae samples analysed at the five laboratories using microscopy of stained smears and culturing were 330 879 (407 positive) and 38 020 (420 positive), respectively. Four laboratories used a Russian non-selective culture medium-that is, Complegon, and one laboratory utilised Biocult-GC. Both media seemed suboptimal. Only two of the laboratories used any species confirmative assay. Antibiotic susceptibility testing of N gonorrhoeae was performed at only two of the laboratories and each year only occasional isolates were analysed. None of the laboratories comprised a complete laboratory quality assurance system.

CONCLUSIONS

According to international recommendations, the diagnosis of N gonorrhoeae in St Petersburg and Leningradskaya Oblast, Russia, is suboptimal. More samples need to be analysed by culturing on a highly nutritious and selective medium and, furthermore, species confirmation and antibiotic susceptibility testing should be more frequently performed. In addition, the utilised methods for culturing and antibiotic susceptibility testing, including medium and interpretative criteria used, ought to be optimised, standardised, and quality assured using systematic internal and external quality controls.

Antimicrobial susceptibility of Neisseria gonorrhoeae in Greece: data for the years 1994-2004

OBJECTIVES

Surveillance data concerning antimicrobial susceptibilities of Neisseria gonorrhoeae isolated in Greece during the 11 year period 1994-2004 are presented.

METHODS

Antimicrobial susceptibilities of all gonococcal isolates received by the Greek National Reference Center for N. gonorrhoeae during the study period were determined in terms of MICs using Etest. Trends in yearly isolation frequencies by susceptibility category were estimated for defining significant changes in overall susceptibility figures.

RESULTS

Cefotaxime and spectinomycin retained undiminished activity against all isolates throughout the study period. High rates of resistance and intermediate susceptibilities were noticed for penicillin, tetracycline and erythromycin, and even for norfloxacin and ciprofloxacin. A substantial portion (16.5%) of the gonococcal samples consisted of multiresistant strains exhibiting resistance to two or more agents of different antibiotic classes. Although annual rates of low-level chromosomal resistance decreased, high-level resistance owing to the presence of penicillin- and tetracycline-resistance plasmids increased. Fluoroquinolone resistance also showed a significant increasing trend after 1996, reaching a peak rate of 11.3% in 2004.

CONCLUSION

Third-generation cephalosporins and spectinomycin should be considered as first-choice drugs for the empirical treatment of gonorrhoea in Greece.

The use of fluoroquinolones in gonorrhoea: the increasing problem of resistance

The recent re-emergence of gonorrhoea in developed countries has been accompanied by the rise and spread of gonococcal resistance to the fluoroquinolones. In the 1980s fluoroquinolones were considered an important addition to the arsenal of agents used to treat gonorrhoea. They proved to be excellent drugs for this indication, including infections caused by penicillinase-producing and tetracycline-resistant strains of Neisseria gonorrhoeae. However, as gonococci have a well-recognised potential to develop resistance to antibiotics, the first reports of reduced susceptibility to fluoroquinolones appeared a few years after their introduction. Gonococcal resistance to fluoroquinolones is now well-established in the Far East, from where it has spread to Australia, Hawaii, California and Europe. In Africa and Latin America, gonococci continue to be susceptible to fluoroquinolones.

Molecular epidemiology of Neisseria gonorrheae isolates with plasmid-mediated tetracycline resistance in Canada: temporal and geographical trends (1986-1997)

Plasmid-mediated resistance to tetracycline in Neisseria gonorrhoeae (TRNG) isolates is caused by the acquisition of a 25.2-MDa conjugative, tetM-containing plasmid (TetM plasmid). The presence of the TetM plasmid is the leading cause of gonococcal resistance to tetracycline in most countries. Between 1986 and 1997, 6,306 TRNG isolates were isolated in different Canadian provincial laboratories and subsequently submitted to the national laboratory for further strain characterization. Because nonculture-based identification of N. gonorrhoeae was more widely used after 1995, this snapshot of the molecular epidemiology of TRNG in Canada, which is only possible if bacteria are cultured, represents a comprehensive data baseline that may no longer be achievable. Temporal trends indicate that TRNG isolations peaked in 1994 (18.9% of isolates tested). Antimicrobial susceptibilities (MIC) to tetracycline and penicillin were determined for 4,064 TRNG isolated between 1986 and 1994. The MICs of TRNG isolates ranged from 16 microg/ml to 32 microg/ml of tetracycline, although one isolate had an MIC of 8 microg/ml and the MICs of four isolates were 2 microg/ml. Penicillinase-producing TRNG (i.e., PP/TRNG) comprised 34.1% of all TRNG (n = 1,386) and 52 TRNG isolates exhibited chromosomal resistance to penicillin. Most of the PP/TRNG (94.1%) carried Africa type (3.2 MDa) beta-lactamase-producing plasmids; only 76 (5.5%) PP/TRNG carried Asia type (4.4 MDa) penicillinase-producing plasmids and three isolates carried Toronto type (3.05 MDa) plasmids. TRNG isolates were also retrospectively typed by auxotype (A), serovar (S), and plasmid (P) content analysis. Eleven auxotype/serovar (A/S) groups comprised the majority (93%) of 4,064 typed TRNG isolates with A/S classes NR/IB-2, NR/IB-3, and NR/IB-1 accounting for 75.1% of the strains characterized. Classification of 670 TRNG for tetM type demonstrated that the Dutch (n = 531) type TetM plasmids predominated over the American (n = 139) type TetM plasmids.

Gonorrhoea in London: usefulness of first line therapies

OBJECTIVES

To determine the true prevalence and patterns of resistance of Neisseria gonorrhoeae to antimicrobial agents used for therapy in London.

METHODS

A longitudinal study of a representative sample of isolates of N gonorrhoeae linked to demographic data of infected patients was undertaken. Isolates were collected from consecutive patients attending genitourinary medicine clinics in the North and South Thames regions of London during 3 months of each of 4 years, 1997-2000. Prevalence of plasmid mediated resistance to penicillin and chromosomally mediated resistance to penicillin and ciprofloxacin was determined by susceptibility testing. The association of antimicrobial resistance among gonococci with sexual orientation of the patient and country of acquisition of infection was determined.

RESULTS

Numbers of gonococcal isolates collected over the same time period between 1997-2000 have increased by 74%. Plasmid mediated resistance to penicillin was low but has risen above 5% in 2000. Chromosomal resistance to penicillin has fallen below the 5% level but total resistance to penicillin, plasmid and chromosomally mediated, was above 5% in all 4 years. The incidence of resistance and reduced susceptibility to the alternative therapeutic choice, ciprofloxacin, is low but numbers are increasing in each year. High level resistance, to both penicillin and ciprofloxacin, has generally been found among heterosexual men and is often acquired abroad. However, there is some evidence of a change to endemic spread in 2000.

CONCLUSIONS

This surveillance programme shows that the epidemiology of gonorrhoea in London is changing with increasing numbers and changing patterns of resistance. If gonorrhoea is to be controlled and targets set by the sexual health strategy are to be met, intervention with effective and appropriate antimicrobial agents is essential.

Surveillance of antimicrobial resistance--what, how and whither?

OBJECTIVE

To express the views of a working party held to consider antibiotic resistance surveillance systems, their strengths and weaknesses, and their current and future applications.

METHODS

The participants, all of whom were experienced in this field, discussed the development of surveillance systems in relation to the increasing prevalence of resistance to antibacterial agents and the current interest in surveillance systems shown by many official bodies, in both the human and veterinary fields. The problems inherent in surveillance systems were considered together with the applications of different systems.

RESULTS

The properties of good antibiotic resistance surveillance systems were defined. Surveillance systems vary widely from those with a narrow base, focusing on few organisms in one disease area, to those covering many diseases, many organisms (including normal flora) and many compounds. Whatever their design, they should be able to detect significant differences and shifts in susceptibility to various antibacterial agents, and the information derived from them should reach as many interested parties as possible in a timely manner. In using this information to decide strategies, criteria for action need to be determined by pragmatic consensus. Funding remains a major problem, with few large studies being supported by official bodies in spite of their professed enthusiasm for surveillance. In consequence, many current systems are funded by the pharmaceutical industry and are of necessity restricted in their focus.

CONCLUSIONS

Antibiotic resistance surveillance studies should and can be well planned and well executed. Many current systems suffer from well-recognized but uncorrected biases. Consortium funding will be necessary for large schemes to be successful. There is no "ideal" surveillance system.

Rise in gonorrhoea in London, UK. London Gonococcal Working Group

We report an alarming 34.9% overall increase in the number of gonococcal infections diagnosed during the same 3 month study period during 3 years. Between 1997 and 1998, an increase of 12.1% was detected, with a larger increase between 1998 and 1999, of 20.4%.