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Antisera QC and IQCP andAssociated ChallengesPatti FieldsEnteric Diseases Laboratory Branch (EDLB)CDC2017 APHL Annual MeetingProvidence, Rhode IslandJune 14, 2017National Center for Emerging and Zoonotic Infectious DiseasesDivision of Foodborne, Waterborne, and Enviromental Diseases
Thank you !Patti [email protected] findings and conclusions in this report are those of the author and do not necessarilyrepresent the official position of the Centers for Disease Control and Prevention.For more information please contact Centers for Disease Control and Prevention1600 Clifton Road NE, Atlanta, GA 30333Telephone, 1-800-CDC-INFO (232-4636)/TTY: 1-888-232-6348E-mail: [email protected]: www.cdc.govNational Center for Emerging and Zoonotic Infectious DiseasesDivision of Foodborne, Waterborne, and Environmental Diseases
Background: Serot yping Serot yping is a subt yping methodCharacterization of strains based on immunologicreactivit y of surface structures, commonly: Lipopolysaccharide (O antigen) Flagellin protein (H antigen)In Salmonella, it is a bit more complicated than otherenteric organisms because: Includes species and subspecies identification becauseisolates of different subspecies can have the same Oand H antigens Most Enterobacteriaceae have only one H antigen;Salmonella commonly has two different H antigens 2500 serotypes have been described (and counting)
Methods for serot yping Phenot ypic methods Detect/differentiate expressed antigens using antibodies Hyper-immune rabbit antisera or monoclonal antibodies Can be a challenged to maintain antisera required 250 reagents needed for all Salmonella serotypes 180 O groups described for E. coliGenetic methods Target genes responsible for serotype: rfb region, fliC, fljB Bonus: Replicates the phenotypic serotyping scheme Target surrogate markers, e.g. , MLST Drawback: Can’t type things you’ve never seen before Variety of methods can be used: PCR, PCR-probe, WGSCDC plans to maintain phenot ypic serot yping “Reference Center for Traditional Microbiological Methods”
Why is serot yping important?Why do we want to keep it? An international “ language”The US has 50 years of Salmonella surveillance databased on serot ypeMany serot ypes have unique niches and/or epidemiology Many do not (or has not been described)No longer the definitive subt yping method We now have genetic subtyping methods that provide aLOT more discrimination than serotyping can Some of the antigenic detail in Kauffmann-White Schemeno longer necessary Can we simplify the serotyping scheme?
Salmonella Serot yping Reagents Many specificities are available from CDCfree-of-charge for the purpose of nationalsurveillanceCDC had funding to replenish antiserasupply in late 1990s- early 2000s APHL was a huge partner. Thanks! Contracted with the state of California toproduce more that 150 regents A “10 year supply” has lasted 15 years, butsome specificities are running out
Salmonella Serot yping ReagentsQC Expiration dates CDC reagents: re-evaluate RTD and extendexpiration dates when needed Antisera QC under CLIA Reagents need to be QC’d every 6 months Not a problem for commonly used reagents QC performed when working dilution is made,used up within 6 months What about rarely used reagents? QC at time ofuse (a LOT of work) Another solution: IQCP
What is IQCP? Individualized Quality Control PlanThe alternative CLIA quality control (QC) option.Provides for equivalent quality testing to meet theCLIA regulations for non-waived tests.Considers the entire testing process: pre-analytic,analytic and post analytic Consider the risks in each of these phases andapplicable regulatory requirements Develop a plan to mitigate egislation/clia/downloads/cliabrochure11.pdf
CDC’s approach to IQCP for serot yping CDC QMS team led us through the processDeveloped one IQCP for all serotyping we do:“Quality control plan for phenotypic determination ofserotype in Campylobacter, Escherichia coli, Salmonella,Shigella, Vibrio cholerae, and Yersinia enterocolitica”Basic organization Purpose and scope Overview of workflow List of risks QC plan to address risks QA plan Supporting documentation
Flow chart
Risks (1 of 3 pages)
QC Plan
Supporting documentation for5-year QC interval for antisera QC records for:155 Salmonella reagents (thanks PHLs!)20 E. coli reagents5-20 reagents for each of the other organisms
Stabilit y of E. coli O and H antisera Antisera produced between 1981 and 1991No change in RTD in 24-34 years (and counting )
Stabilit y of Salmonella serot yping reagentsSummary by reagent type#reagents3CategoryReagents that failed QCReagents that never failed QC (yet)Monoclonal antibody reagents, H antigens3Monoclonal antibody reagents, O antigens25Absorbed rabbit antiserum reagents, H antigens28Rabbit antiserum reagents, H antigens53Rabbit antiserum reagents, O antigens41Rabbit antiserum reagents, Vi antigen2Total155% of reagents that never failed QC (yet) 98.1% # mary by number of yearsreagent lasted# years#% oflastedreagents 17% 251711%Total152100%Did not track when a lot was depletedShorter “ # years lasted” could be due to missing QCrecords or a lot being depletedOldest Salmonella reagent on inventory is 36 years oldReagents made by the state of California are 13 to 20years old (or depleted).
Salmonella serot yping reagents tantiseraO10,mousemonoclonalantibodyYear ofManufacture197919982000Year of lastQC pass20022004na# years lastedbefore failureWhat happened?234/2009: CDC was alerted by a SHDthat the reagent failed their QC.Result confirmed at CDC the nextday. Lot removed from inventory andother states notified via EntericBacteriology Listserv.612/2006: Routine testing at CDCindicated titer had fallen and crossreactions seen at revised RTD. Lotremoved from inventory and statesnotified via Enteric BacteriologyListserv.na8/2010: Reagent failed QC whiletesting bulk in advance of dispensing.Reagent is a blend of twomonoclonal antibodies and it appearsone died.
CDC is happy to assist in any waywe can with QC and QA issues CDC Enteric Bacteriology Discussion [email protected] Contact Blake Dinsmore at [email protected] if youwould like to be added to the list. Salmonella Lab Inbox [email protected] Team Inbox [email protected] Patti [email protected] 639 1848
Thank you !Patti [email protected] findings and conclusions in this report are those of the authors and do not necessarilyrepresent the official position of the Centers for Disease Control and Prevention.For more information please contact Centers for Disease Control and Prevention1600 Clifton Road NE, Atlanta, GA 30333Telephone, 1-800-CDC-INFO (232-4636)/TTY: 1-888-232-6348E-mail: [email protected]: www.cdc.govNational Center for Emerging and Zoonotic Infectious DiseasesDivision of Foodborne, Waterborne, and Environmental Diseases
Salmonella Serot yping ReagentsCDC InventoryCategoryH monospecificH monospecificH monospecificH monospecificH monospecificO groupingO monospecificO monospecificO monospecificH typingH monospecificReagent27vz24z2828789yz51Statusout of stockout of stockout of stockout of stockout of stockout of stocklowlowlowlowlowSolutionbulk available for dispensingbulk available for dispensingbulk available for dispensing
What is IQCP? Individualized Quality Control Plan The alternative CLIA quality control (QC) option. Provides for equivalent quality testing to meet the CLIA regulations for non -waived tests. Considers the entire testing process: pre- analytic, analytic and pos
