Fourth Meeting of the
International Collaboration on Gonococci (ICG)
in conjunction with the
International Society for Sexually Transmitted Diseases
Research (ISSTDR) Congress
Ottawa, Canada, Thursday, July 31, 2003
Attendance: Approximately 40 people attended the meeting.
Dr John Tapsall of the WHO Collaborating Centre for STD and HIV, Sydney, Australia and Dr Susan Wang of the Centers for Disease Control & Prevention, Atlanta, Georgia, United States, were co-chairpersons for the meeting.
The ICG aims to bring together those groups currently performing gonococcal antimicrobial resistance (GC AR) surveillance and others interested in this activity to enhance surveillance outcomes and knowledge. GC AR severely compromises control of gonococcal disease, preventing effective treatment of individuals, increasing morbidity and complications, and enhancing the transmission of HIV. Effective treatment and control of gonorrhea depends on having readily available data on Neisseria gonorrhoeae antimicrobial resistance patterns. The ICG arose from initial discussions between WHO and CDC in May 2000 with a view to enhancing production of and access to global data on GC AR. There have been several initiatives by WHO and CDC directed at addressing the general problem of antimicrobial resistance in recent years
- UNAIDS/WHO Guidelines for Sexually Transmitted Infections Surveillance);
- WHO Surveillance Standards for Antimicrobial Resistance Monitoring;
- WHO Global Strategy for Containment of Antimicrobial Resistance and a companion document, Antimicrobial Resistance in Neisseria gonorrhoeae,
- U.S. Public Health Action Plan to Combat Antimicrobial Resistance .
To further enhance GC AR surveillance, an informal meeting of interested parties was convened by Dr John Tapsall and Dr Susan Wang at the November 2000 International Pathogenic Neisseria Conference (IPNC) in Galveston, Texas where attendees identified the extent and type of GC AR surveillance that was taking place around the world. A second meeting was held at the June 2001 International Society for Sexually Transmitted Diseases Research (ISSTDR) Conference in Berlin, Germany where several Work Groups were formed to consider and make recommendations on specific issues relevant to GC AR surveillance. The Work Groups that were formed include: Diagnostics, Gonococcal typing systems, Laboratory quality, Sampling and methodology, and Resistance mechanisms and ICG website development (see Appendix 1 for Work Group participants). Following the Berlin meeting, the name (International Collaboration on Gonococci or ICG) was adopted, an e-mail discussion group was set up, and Work Groups began their activities. A third meeting was held at the September 2002 IPNC in Oslo, Norway when the Work Groups reported on their initial work.
Membership to the ICG is free and open to anyone working in the broad areas of epidemiology, microbiology, and management of gonococcal disease. ICG members are encouraged to join and contribute to one or more of the Work Groups; suggestions for the formation of additional groups are always welcome.
The Aims of the ICG are defined as follows:
- To provide timely information for action regarding the most appropriate and cost effective antibiotic treatment for gonococcal disease by monitoring the geographic and temporal emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae. (Pertinent Work Groups are Sampling and methods; Laboratory quality; Website and data reporting)
- To obtain a better understanding of the mechanisms of resistance in the gonococcus and its relationship to the biology of the organism to assist in efforts in disease control. (Pertinent Work Groups are Diagnosis and Gonococcal typing).
Sampling and Methods Dr John Tapsall
Dr Tapsall reviewed the requirements for a satisfactory antimicrobial resistance surveillance system (WHO Surveillance Standards for Antimicrobial Resistance Monitoring) as:
- proper epidemiology appropriate sampling in terms of sample size and sample population;
- proper microbiological procedures especially including quality control and quality assurance; with test systems based on a consideration of the type of surveillance planned: susceptible/resistant data only or MIC trend data;
- proper outcome measures - a) mechanism of data analysis, b) production and dissemination of data report, c) implementation/effect on policy.
Dr Tapsall noted that we often have denominator-deficient surveillance that leads to collection of indicative data that can be hard to interpret. He noted that key questions are what is the number of gonococcal isolates that are needed for testing to produce valid data? or conversely, I only have x isolates, how valid is my data? The answer is that it depends on what the data are used for. Dr Tapsall proposed that, in the initial stages of establishing surveillance, one should concentrate on providing data that guided the selection of public health (programmatic) treatments with the aim of curing a minimum of 95% of gonorrhea cases. Thus, one would want a sample size that has the power to detect a 5% resistance threshold. Dr Tapsall noted that types of surveillance systems could vary from being sentinel surveillance systems vs comprehensive (ideal), and episodic vs continuous (ideal). The variations in types of surveillance systems will affect the requirements for sample size.
Dr Tapsall noted that for the purpose of sampling for public health treatment, about 300 isolates would be needed to reliably detect a 5% resistance level in one setting. To establish trend data using Lot Quality Assurance (LQA) methods, existing LQA tables suggest that one needs higher numbers of isolates. For example, to detect a significant change, say going from 2% to 5% resistance at 95% CI requires 400 isolates in each of two samples. Conversely, if resistance data on only x isolates are available, the range of probable resistance can also be calculated. However, one will be starting from some assumptions, e.g., that gonococcal antimicrobial resistance is randomly distributed although this is probably not the case.
A pragmatic proposal suggested by Dr Tapsall is that 100-200 isolates be routinely obtained and examined by defined procedures. If no (0-1%) or very high level (>20%) resistance is detected, one might feel comfortable that the sample is correctly representing the true level of resistance. However, if the prevalence of resistance among this small number of isolates is found to be 2- 8%, i.e., the action range, one would need enhanced surveillance and extra power to have more confidence in the true level of resistance. More surveillance data would be needed to determine the resistance prevalence more precisely to assist with programmatic decisions.
Laboratory Quality Dr Joan Knapp
Dr Knapp reported working on a new international quality control (QC) strain panel with 5 core laboratories (Sydney, London, Winnipeg, Ottawa, Atlanta) and volunteer partners (Denmark, Sweden, New Zealand - Wellington and Auckland). Each laboratory used its own routine test procedures and results were interpreted using local criteria. The routine test procedures by the various laboratories meant that 7 different media were being used (Oxoid, Difco, BBL, chocolate agar, various supplements, etc.). For Phase I, the core laboratories tested 30 strains (10 strains in triplicate); these strains included 7 CDC-USA QC strains. The volunteer partners tested 15 cultures (5 of 7 CDC-USA QC strains). For Phase II, the core laboratories tested 60 cultures (20 strains in triplicate); these strains included 15 strains (including 2 WHO reference strains) from Australia, 4 strains (including 3 WHO reference strains), and 1 (azithromcyin MIC 1.0 mg/L) strain from the USA.
The Phase I comparison has been completed and show that modal MICs vary by method used. MICs are not directly comparable between methods. To minimize under- or over-reporting of resistance, it was decided to compare results by using resistance phenotypes defined by local interpretive criteria, i.e., interpretive criteria used by the respective core laboratories, to determine if this method would allow comparison of susceptibilities determined by different methods.
In Phase II, in addition to reporting MICs, laboratories reported the resistance phenotypes based on their respective interpretive criteria (when comparing phenotypes, intermediate MICs were grouped with susceptible MICs). A high degree of agreement was noted between the resistance phenotypes identified for each culture by the laboratories. However, some disagreement between resistance phenotypes was noted for individual strains, indicating that it may be necessary to reevaluate some interpretive criteria to allow comparison between results obtained with different methodologies.
The next steps for this activity are:
- complete data collection and analysis;
- select a new QC reference panel;
- develop and implement an external QA protocol;
- evaluate future candidate QC strains.
There was discussion about the value of publishing an inventory of basic media systems and of publishing the MIC ranges of QC strains with appropriate interpretive criteria for particular methods.
Dr Lai King Ng suggested that the group consider depositing control strains into the American Type Culture Collection (ATCC) or the National Collection of Type Cultures (NTCC) to allow for easier distribution to requesting laboratories.
Dr Cathy Ison raised two issues: 1) how to make QC strains available, and 2) how QA programs could be run globally. Currently, there are existing QA programs in place for a number of GC AR surveillance networks. The general feeling was that once ICG finalized agreement on a new QC reference strain panel, the existing surveillance networks should be the repository for the strains and use/distribute them in their laboratory networks. It was felt that it was not practical to have a single global QA program for a number of reasons, including local needs and costs. A more practical approach was to maintain an overarching QA amongst the coordinators of the surveillance networks themselves who would then oversee/report problems with existing reference strains and liaise on the introduction of new reference strains.
A helpful hint for improving recovery of gonococci from lyophiles was described by Dr Knapp and should assist those who send and receive GC cultures preserved in this way: if a lyophilised culture is inoculated but fails to grow after 24 hrs, then if one simply re-streaks the plate and re-incubates it, a substantially higher recovery may be obtained.
Diagnostics Dr John Tapsall for Dr Hugh Young
Dr Tapsall noted that Dr Young would like to survey ICG members to see how many are performing culture vs other diagnostic methods. An initial draft of the survey was too complex so the survey is being simplified and will be re-sent to all. There was brief discussion of two ISSTDR abstracts (Unemo, 653 prolyliminopeptidase-negative isolates and Tapsall, 129 PCR-false-negative, culture-positive isolates) with interest in having these issues be a focused point of discussion via e-mail or at a future meeting. The latter abstract led to a discussion on the use of sequences from the cryptic plasmid for nucleic acid amplification tests for GC. The Canadian experience where many GC strains dont have the cryptic plasmid and thus produce false-negative results was described. Dr Helen Palmer mentioned her recent JCM paper on PAU-GC lacking the cryptic plasmid (see also the Oslo ICG meeting report and J Clin Microbiol 2003;41:835-837).
Molecular typing and susceptibility testing in the absence of culture Dr Lai King Ng
Dr Ng discussed the micro-array as a new platform for multiple organisms which could identify GyrA, ParC mutations and capillary electrophoresis which can look at a single point mutation. With regards to typing, Dr Ng noted that Bionumeric or GelCompare is a computer software system that allows comparison of PFGEs, sequences, MLST, etc. This computer system has the capacity to exchange large imaging files. Laboratories could exchange and standardize PFGE results for control strains, for example, through this system.
Dr David Trees expressed concern that microarrays will only detect what is known but since there is diversity in mutation patterns, genetics wont consistently predict MICs. He also noted his ISSTDR poster (Trees, 428) described use of the Gonostat Transformation Assay for detection of antimicrobial resistance without culture for only ~$1.65/test, although it would not be possible to strain-type the isolates since all isolates would have wild-type DNA. Additionally, the likelihood that all genes will come through in one transformation is dependent on the mechanism, so this susceptibility testing method may not work consistently for all antimicrobials.
Website Dr Jo-Anne Dillon
Dr Dillon hopes to be able to continue to develop the ICG web site (http://www.med.uottawa.ca/icg/organization.html) once her responsibilities as ISSTDR organizer are over.
Mapping of GC AR data Dr John Tapsall
Dr Tapsall reported that WHO has funding to map various related demographic and disease data. Dr. Annapaola de Felici had reported plans on this initiative at the Berlin ICG meeting in 2001. The WHO has a prototype system for GC AR mapping which may be accessed on http://www.who.int/csr/drugresist/infosharing/en/. Currently, this displays WPRO data for 2001 as a color density map, and the data are linked to WHO treatment recommendations. The WHO is a passive recipient of the data which it then translates into the maps shown, but requires that the data displayed be validated and reliable. WHO has a requirement that the basis of the data and its validation be available with the data (see the illustrative maps at the website above for examples.) Dr Tapsall believes that WHO would be interested in displaying GC AR data and would be interested in having ICG be responsible for vetting and assuring the quality of such data. He suggested a number of means of achieving this, including having the WHO website link to recent, peer-reviewed and published GC AR data or annotating and supplying data that are published but not available electronically. It would be valuable to also include who is supplying the data, information on the type of surveillance system, and information on sample population and isolate sources. If WHO and ICG could come to some accommodation on this point it would be of mutual benefit. Dr Tapsall will communicate further with WHO on this point.
Typing Dr Cathy Ison
Dr Cathy Ison reported on the first international comparison of molecular typing methods (see ISSTDR abstract - Bash, 364). Dr Ison distributed a panel of 18 strains (collected during 1979-1994 from various countries, all different A/S classes) in late 2002 and received strain typing results from all the participating laboratories by March 2003. By auxotyping, 6 strain types were identified; by MLST with PCR-RFLP-por, 13 strain types were identified; by Lip typing, 15 strain types were identified; by porVR, 17 types were identified; and by por sequencing (partial or complete), PFGE, MLST (13 genes), NG-MAST, 18 types were identified. A sexual contact pair of isolates was correctly identified by all strain-typing methods. All methods had some level of discrimination. Dr Ison noted that a future strain typing comparison should be considered using a larger sample of strains that are more broadly representative.
Dr Ison noted that different typing methods serve different purposes. Typing methods for global surveillance or population assessment vs for outbreak assessment would likely need to be different. Discussion about typing methods ensued. PFGE is more discriminatory but it may be difficult to do inter-laboratory standardization and comparison. Cluster analysis may be better served by por typing. Sequencing, especially multi-locus, may be a better way to go than PFGE. Dr Margaret Bash noted that perhaps the question should be framed not so much as what is typing used for?, but rather, if we could do rapid typing, what could we use typing for? There is a need for typing methods to be geared to non-viable specimens such as described in two ISSTDR posters (Bash 459 and 576), since viable isolates are becoming more and more rare in this era of non-culture GC testing.
- Dr Ison reported that the European Union had funded the establishment of European STI Surveillance. As part of an effort to understand the current status of GC AR surveillance, Dr Ison had developed a questionnaire for diagnostic laboratories and another questionnaire for reference laboratories to find out what GC diagnostic methods were being used, how many GC isolates were being susceptibility tested, and what susceptibility test methods were being used. In addition, 30 strains (10 strains in triplicate) had been shipped to 14 countries for susceptibility testing to find out what the range of susceptibility results would be between the various laboratories.
- Dr Dillon noted that for South America and the Caribbean, lack of money continued to make regular GC AR surveillance difficult. She noted that she was heartened that several places have established some surveillance and the impact of the surveillance included: 1) treatment guideline changes away from penicillin, 2) standardization of testing methods via QC data.
- Dr Beryl West also reported ups and downs in the West Africa GC AR surveillance. The basics of the surveillance system are in place and reference strains have been shipped out. Countries often want to do it but dont have facilities.
- Dr Tapsall reported that WHO SEARO GASP surveillance was still in existence, that data were being produced, and that plans were in place to enhance the surveillance activity. The WHO WPR GASP continues to operate but function was dependent on funding. He noted that one issue is setting up a surveillance network, but the larger issue is the maintenance of the network. Not only is consistent funding an issue, but turn-over in staff and re-training is an ongoing challenge.
- Dr Tetsuro Muratani briefly described the increases in numbers of isolates resistant to penicillins, quinolones, tetracyclines, aztreonam, and cephems in Japan (see ISSTDR abstracts, Muratani 375 and Akasaka 377).
- Dr Xiaohong Su noted that in China there had been some reports of possible ceftriaxone treatment failures in Guangzhou and in Hunan. She expressed concern about the quality and potency of local antibiotics, especially ceftriaxone and also noted that some clinicians dont follow treatment guidelines.
- Dr Susan Wang gave a brief update on the availability of antimicrobials; spectinomycin continues to be available in the U.S. and Canada, while cefixime is no longer available. There are currently no oral antimicrobials that are available and CDC-recommended to treat fluoroquinolone-resistant GC.
- Because the spread of QRNG was extensively presented at ISSTDR via posters and during an oral session, it was decided not to have further discussion of QRNG during this meeting.
ICG members are encouraged to sign up to participate in any (and multiple!) Work Groups in which they are interested members should contact the relevant Work Group Coordinators (Appendix 1). Additionally, ICG members are asked to identify other colleagues who may be interested in joining ICG and encourage them to contact Dr Wang (e-mail: email@example.com) or Dr Tapsall (e-mail: firstname.lastname@example.org) so that new colleagues may be added to the ICG contact list.
ISSTDR meetings seem to provide the best settings for face-to-face ICG meetings because they are well-attended by people interested in GC. It was not decided whether the September 2004 International Pathogenic Neisseria Conference (IPNC) in Milwaukee will be a good forum for the next ICG meeting or not; an e-mail survey of ICG members will be done to help decide the location and date of our next meeting.
Appendix 1 Work Groups
Laboratory quality Dr Joan Knapp (email@example.com)
Lai King Ng
Resistance mechanisms and Website Dr Jo-Anne Dillon (firstname.lastname@example.org)
Lai King Ng
Sampling and methods Dr John Tapsall (email@example.com)
Lai King Ng
Diagnostics Dr Hugh Young (Hugh.firstname.lastname@example.org)
Lai King Ng
Gonococcal typing Dr Cathy Ison (email@example.com)
Lai King Ng
Eddie Van Dyck
Appendix 2 Current ICG e-mail list
Per Olcen Sweden
Rafael Llanes Cuba
Hans de Neeling Netherlands
Sudershan Kumaris WHO SEARO
Jo-Anne Dillon Canada
Susan Wang USA
Xiaohong Su China
Hugh Young United Kingdom
Magnus Unemo Sweden
Hans Fredlund Sweden
Marilyn Roberts USA
Lai King Ng Canada
Waleria Hrynicwicz Poland
Paula Kriz Czech Republic
Helen Palmer United Kingdom
Margaret Bash USA
Hanne Winther-Larsen Norway
Barbara Albiger Sweden
Steve Dunham USA
Inge Lind Denmark
Joan Knapp USA
B. Garin New Caledonia
Celia Carlos Philippines
Dr. Rohani Malaysia
Dr Ling Singapore
Tony Lupiwa Papua New Guinea
Dr Kam Hong Kong
Mike Brokenshire New Zealand
Andrew Darcy Solomon Islands
Masatoshi Tanaka Japan
Ane Ika Tonga
Helen Wamle Vanuatu
Port Moresby Hospital Papua New Guinea
Dr Lee Korea
Dr Kuroki Japan
Erinechimeg Lakhsuram Mongolia
William Levine USA/Thailand
Pachara Srivongrangsan Thailand
Motiur Rahman Bangladesh
Eddie van Dyck Belgium
Joke Spaargaren Netherlands
John Gallwey Thailand
Philippe Mayaud United Kingdom
Verapol Chandeying Thailand
Beryl West West Africa
Kevin Fenton United Kingdom
Jorge Sanchez Peru
Rosa Galvan Peru
Andrew Turner United Kingdom
David Trees USA
Caroline Ryan USA
Hillard Weinstock USA
Marius Domeika Sweden
Olli Haikala Finland
William Ferreira Brazil
Albert Vinnikoff Ukraine
Steen Hofman Denmark
Julio Vazquez Spain
Iona Martin United Kingdom
Graham Nielsen Thailand
TD Chugh Kuwait
Yue-Ping Yin China
Cathy Ison United Kingdom
Clara Witt USA
Veronique Goulet France
Joselito Pedrosa Brazil
Jose Carbajel Peru
Graciela Borthagaray Uruguay
Andrew Herring United Kingdom
Carlos Conde Mexico
Sephir Tabrizi Australia
William Shafer USA
Robin Bailey United Kingdom
Tetsuro Muratani Japan
John Tapsall Australia
John Bates Australia
Alistair McGregor Australia
Mark Gardam Australia
Paulette Lee Australia
Jan Lanser Australia
Julia Pearson Australia
Peter Collignon Australia
Elisabeth Wedege Norway
Frank Bowden Australia
Angela Merianos Australia
Angelika Stary Austria
Asesh Banerjee USA
Federica Di Marcello Italy
Elisabetta Monaci Italy
Anna Shakarishvili USA
Joel Lewis USA
BSN Reddy India
Michael Dan Israel
Torsten Berglund Sweden
Lai Wei China
Toshiro Kuroki Japan
Colin Block Israel
William Antunes Ferreira Brazil
Weiming Gu China
Peter Kilmarx USA/Botswana
Michael St. Louis USA
Mafiz Rahman Botswana
Edgard Lafia Senegal
Preena Bhalla India
Thomas Lund Sorensen Denmark
Herida Magid France
Zheng Heping China