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

Diagnostics of Gonococcal Infection in Ukraine: Current Challenges in Resource-Constrained Settings

OBJECTIVE

This study aimed to evaluate the compliance of laboratory diagnostics of gonorrhoea in Ukraine with the World Health Organization (WHO) laboratory manual.

MATERIALS AND METHODS

A quantitative non-randomised cross-sectional descriptive postal survey was conducted to evaluate the diagnostics of gonorrhoea in sexually transmitted infections (STI) clinics in Ukraine.

RESULTS

The survey provided data about diagnostics of Neisseria gonorrhoeae in STI clinics from 14 regions of Ukraine from January 2013 to September 2014. The clinics performed microscopy, culture, and point-ofcare- testing in 100%, 85.7%, and 7.1% of the cases, respectively. None of the respondents had the option of performing nucleic acid amplification tests and antimicrobial susceptibility testing. Two regions reported their participation in the collaborative project by WHO on antimicrobial resistance investigation, as national antimicrobial susceptibility surveillance program had not been established in Ukraine. A "three-site testing" (urogenital, pharyngeal, and rectal specimens) in symptomatic heterosexuals was conducted by 25%, "twosite testing" (urogenital and pharyngeal specimens) was conducted by 41.7%, and "one-site testing" (urogenital specimen) was conducted by 33.3% of the respondents. External quality control of laboratory tests for the detection of N. gonorrhoeae was not performed in 50% of the regions in Ukraine. Non-selective culture media for isolation of N. gonorrhoeae and culture media in tubes instead of the recommended Petri dishes were used in 16.7% and 58.3% of the laboratories, respectively.

CONCLUSION

Increased adherence to evidence-basedWHO and/or nationally adapted management guidelines is essential for monitoring gonorrhoea and preventing antimicrobial resistance of N. gonorrhoeae in Ukraine.

Comparison of deferred and bedside culture of Neisseria gonorrhoeae: a study to improve the isolation of gonococci for antimicrobial susceptibility testing

BACKGROUND AND OBJECTIVES

Antimicrobial resistance of Neisseria gonorrhoeae is globally spread and threatening. Culturing of N. gonorrhoeae is the only method to collect live isolates for investigation antimicrobial resistance profile. Therefore, quality assessment of N. gonorrhoeae culture is essential for successful isolation of gonococci. This study was conducted to evaluate deferred and bedside culture of N. gonorrhoeae depending on the year season and temperature condition of transport media temporary storage.

MATERIALS AND METHODS

Urogenital swabs from 46 symptomatic heterosexual patients with gonorrhoea and subculture of N. gonorrhoeae in 46 suspensions in concentrations 1.5 × 10⁸ CFU/ml were subjected to the study. Non-nutritive transporting medium Amies Agar Gel Medium with charcoal (Copan Diagnostics Inc., Brescia, Italy) was used for deferred culture and selective Chocolate agar TM+PolyViteX VCAT3 (BioMérieux, Marcy-l'Étoile, France) for both tested methods of culture.

RESULTS

The specificity of both bedside and deferred methods of culture was 100%. The sensitivity of deferred culture was higher than of bedside culture (82.6% vs 47.8%, p<0.0005). Deferred culture showed significantly higher sensitivity comparing to bedside culture in summer (100% vs 50%, p=0.003), and comparably the same as for bedside culture in autumn, winter and spring.

CONCLUSION

The viability of N. gonorrhoeae subcultures was significantly higher in refrigerated samples from transport media than from ambient one after exposition from 48 to 96 hours. Optimal viability of N. gonorrhoeae was observed when transport swabs were kept refrigerated up to 48 h (73.9-93.5%) or ambiently - up to 24 h (87%). Updating laboratory guidelines regarding sampling and timely specimen processing might improve gonococcal culture performance.

Current status of gonococcal antimicrobial susceptibility with special reference to Azithromycin and Ceftriaxone: Report from a tertiary care hospital in Bangladesh

Objectives:

Successful treatment of gonorrhea has always been jeopardized by the emergence of resistance to antibiotics recommended as first-line therapies. The present investigation was carried out to demonstrate the current status of antimicrobial susceptibility of N. gonorrhoeae with a special reference to azithromycin and ceftriaxone.

Methods:

Microscopical detection in Gram-stained smear and isolation by culture in Thayer-Martin medium were done for 60 clinically suspected gonorrhea patients using urethral discharge or prostatic secretion for male and endocervical secretion for female. Isolates of N. gonorrhoeae were subjected to antimicrobial susceptibility testing by modified Kirby Bauer disk diffusion method against eight antimicrobial drugs including azithromycin and ceftriaxone.

Results:

Culture yielded a total of 25(42%) isolates of N. gonorrhoeae from 60 clinically suspected patients of both sexes; 21 from male (17 from urethral discharge and 04 from prostatic secretion) and 04 from female (endocervical secretion). Isolates of N. gonorrhoeae showed moderate to high resistance (60 to 88%) to penicillin, tetracycline, cotrimoxazole, erythromycin, ciprofloxacin and cefixime. While resistance to azithromycin and ceftriaxone was 60% and 48% respectively, which was also moderate.

Conclusion:

Our findings indicate moderate to the high resistance of N. gonorrhoeae to conventional antibiotics. It also showed moderate resistance to azithromycin and ceftriaxone, current dual therapy recommended by the WHO for the treatment of genital gonorrhea, which is alarming.

Estimates of the number of prevalent and incident human immunodeficiency virus (HIV) infections in Canada, 2008

OBJECTIVE

To estimate the number of prevalent and incident HIV infections in Canada in 2008.

METHODS

We applied multiple methods to estimate national HIV prevalence and incidence in Canada, including the workbook method, two statistical modelling methods, and an iterative spreadsheet model.

RESULTS

The estimated number of people living with diagnosed or undiagnosed HIV infection (including AIDS) continues to rise, from an estimated 57,000 in 2005 to 65,000 in 2008. Nearly half (48%) of these HIV-infected persons were men who have sex with men (MSM) and 22% were women. An estimated 16,900 persons with prevalent infection (26% of total prevalent infections) were unaware of their HIV-infected status and this proportion varied from an estimated 19% of HIV-infected MSM, to 25% of HIV-infected people who inject drugs, and 35% of HIV-infected heterosexuals. An estimated 3,300 new infections occurred in Canada in 2008, which was about the same as the estimate of 3200 in 2005. Of those new infections, 26% were among women and 12.5% were of Aboriginal descent; in terms of exposure category, MSM continued to comprise the greatest proportion of new infections (44%) and heterosexuals who originated in countries where HIV is endemic comprised 16%.

CONCLUSION

HIV incidence in Canada is not decreasing. Aboriginal people and people from HIV-endemic countries continue to be over-represented in Canada's HIV epidemic. People unaware of their HIV infection are a priority for being tested and diagnosed to enable them to take advantage of care services and receive counselling to prevent further spread of HIV.

Comparison of microscopy, culture and in-house PCR and NASBA assays for diagnosis of Neisseria gonorrhoeae in Russia

This study aimed to assess the laboratory diagnosis of Neisseria gonorrhoeae in St. Petersburg, Russia. In total, 334 consecutive symptomatic patients were enrolled. Cervical and urethral specimens from women (n=286) and urethral specimens from men (n=48) were analyzed by microscopy, culture and two in-house NAATs, i.e. polymerase chain reaction (PCR) and nucleic acid sequence-based amplification (NASBA), developed in Russia. All N. gonorrhoeae-positive samples were confirmed using porA pseudogene and 16S rRNA gene sequencing. All methods displayed 100% specificity, i.e. positive predictive values of 100%. Compared to the PCR (most sensitive method in the present study), in women the sensitivity of both microscopy and culture was 31.8%, and that of NASBA was 90.9%. In men, microscopy, culture and NASBA displayed a sensitivity of 75%, 50% and 100%, respectively. The negative predictive values of microscopy, culture, and NASBA were 97.3%, 97.3%, and 99.6% in women, and 97.8%, 95.7%, and 100% in men, respectively. According to the PCR, the prevalences of N. gonorrhoeae were 4.5% (women) and 8.3% (men). In conclusion, both the investigated Russian NAATs displayed a high sensitivity and specificity. However, in general the diagnosis of gonorrhoea in Russia is suboptimal and crucially requires validation, improvements and quality assurance.

Neisseria gonorrhoeae population in Arkhangelsk, Russia: phenotypic and genotypic heterogeneity

Reliable data concerning the incidence and phenotypic and genotypic characteristics of the Neisseria gonorrhoeae population in many eastern European countries are lacking. Clinically significant N. gonorrhoeae isolates (n = 76) from 76 consecutive patients in Arkhangelsk, Russia were characterised by antimicrobial susceptibility testing, serovar determination, porB gene sequencing and N. gonorrhoeae multi-antigen sequence typing (NG-MAST). The isolates were assigned to 12 different serovars, displayed 35 divergent porB sequences, and belonged to 40 different sequence types (STs). All the serovars, but only seven of the STs, had been identified previously in other countries. Twelve ST clusters of between two and 14 isolates were identified, which indicated that many multiple transmission networks exist in Arkhangelsk. The high number of unique STs (n = 28) may be a consequence of sub-optimal diagnostic procedures, ineffective partner tracing, local emergence of new STs, import of strains via sexual tourists, or foreign travel. The N. gonorrhoeae population circulating in Arkhangelsk was highly diverse and differed from the N. gonorrhoeae populations disseminated in some western European countries. Thorough knowledge concerning the incidence of gonorrhoea, antibiotic susceptibility and other phenotypic and genotypic characteristics of the N. gonorrhoeae strains circulating in eastern Europe is crucial.

Antibiotic susceptibility of Neisseria gonorrhoeae in Arkhangelsk, Russia

OBJECTIVES

To characterise comprehensively the antibiotic susceptibility of Neisseria gonorrhoeae in Arkhangelsk, Russia, and to investigate whether the recommended treatment guidelines are updated and effective.

METHODS

The susceptibility of N gonorrhoeae isolates, cultured during June-November 2004 mainly from consecutive patients with gonorrhoea (n = 76) in Arkhangelsk, to penicillin G, ampicillin, cefixime, ceftriaxone, ciprofloxacin, erythromycin, azithromycin, kanamycin, spectinomycin and tetracycline was analysed using Etest. Nitrocefin discs were used for beta-lactamase detection.

RESULTS

The levels of intermediate susceptibility and resistance to the different antibiotics were as follows: penicillin G 76%, ampicillin 71%, cefixime 0%, ceftriaxone 3%, ciprofloxacin 17%, erythromycin 54%, azithromycin 14%, kanamycin 49%, spectinomycin 0% and tetracycline 92%. Of the isolates 55 (72%) were determined as multiresistant--that is, they showed intermediate susceptibility or resistance to three or more classes of antibiotics. However, none of the isolates were beta-lactamase producing.

CONCLUSIONS

In Arkhangelsk, and presumably in many other areas of Russia, penicillins, ciprofloxacin, erythromycin, azithromycin, kanamycin and tetracycline should not be used in the treatment of gonorrhoea if the results of antibiotic susceptibility testing are not available. In Russia, optimised, standardised and quality-assured antibiotic susceptibility testing needs to be established in many laboratories. Subsequently, continuous local, regional and national surveillance of antibiotic susceptibility is crucial to detect the emergence of new resistance, monitor changing patterns of susceptibility and be able to update treatment recommendations on a regular basis.