āāGradient Strip (GC ETest) Neisseria gonorrhoeae, Antimicrobial Susceptibility Testing Services Frequently Asked Questions (FAQ)
June 26, āāā2023
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Whaāt types of samples should we sāend?āāāā
- The following
Neisseria gonorrhoeae pure isolates may be submitted to the California Department of Public Health (CDPH), Microbial Diseases Laboratory (MDL) for Gradient Strip (Etest) Antimicrobial Susceptibility Testing (AST).
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āāāāN. gonorrhoeae isolates with decreased susceptibility to cefixime (MIC ā„0.25 Āµg/mL), ceftriaxone (MIC ā„0.125 Āµg/mL), and azithromycin (MIC >16 Āµg/mL). āā
āāā
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N. gonorrhoeae isolates from suspected treatment failures (Clinical Guidelines for Gonorrhea Treatment and Management of Suspected Treatment Failure āPDFā) and isolated from sites, including but not limited to urethra, endocervix/vagina, rectum, pharynx, blood, synovial fluid and eye.
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N. gonorrhoeae isolates from disseminated gonococcal infections (DGI).ā
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N. gonorrhoeae isolates from ocular infections.
- Pre-approval for other N. gonorrhoeae isolates not meeting the listed criteria will be determined on a case-by-case basis after consultation with STD program at
stdcb_argc@cdph.ca.gov. ā
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- Primary clinical specimens for culture isolation are not accepted by MDL at this time. Primary clinical specimens from suspected treatment failures may be tested via the Antimicribal Resistance Laboratory Network regional laboratory in Washington state. Contact stdcb_argc@cdph.ca.gov or
MDL.Submissions@CDPH.ca.govāā for submission instructions. ā
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āHow should samples be sent in for the laboratory testing?āā
- āāāInstructions for submission of isolates to the MDL Bacterial Diseases Section (BDS):
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- āāSubmitters can use one of the following submittal methods: āāā
- āāāāāMDL Lab Web Portal (LWP) (Prefeārred)āā. If your laboratory is already enrolled on the MDL LWP please go to āMDL Lab Web Portal (LWP)āāā. āSubmitters interested in using MDL LWP please contact the CDPH LWP team at
cdph_lwp_admin@cdph.ca.gov.ā
- MDL barcode submittal form. If you donāt have access to MDL LWP please use the MDL barcode submittal form:
MDL Submission Instructions and Forms. ā
- āāāāUnder the Select Test Requisition field, select the Antimicrobial Susceptibility Testing-AST form.
- Please ātāype in patient, submitter and test requistion information into electronic submission form. ā
- Type in the genus and species identification on the submittal form in the āSubmitterās Identification of Organismā box. āā
- Follow the directions to select the test requested as āN. gonorrhoeae Etestā in the āTest(s) Requestedā box on the Page 2.
- Provide a copy of isolate AST results or/and other patient records that would indicate suspected treatment failure. āā
- The reason for requesting testing (e.g., suspected treatment failure) should be entered in the āOther Tests or Comments Fieldā on Page 2. Additionally, if applicable, the name and contact information of the provider/entity requesting the isolate be sent for testing can also be entered here.
- āāEnter Travel history on Page 1. Please include most recent international or interstate travel within
one month prior to specimen collection (if available).
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- āPrepare culture for submission.
- āāIsolates must be identified as
N. gonorrhoeae by the submitter.ā
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- Mixed cultures received by MDL will not be tested.
- Refer to
Disseminated Gonococcal Infection (DGI) Guidance for Laboratories for detailed procedures. The āSpecimen preparation for transportā instructions can be used for preparing any
N. gonorrhoeae isolate for shipment to CDPH. The instruction is briefly described as following. āāāā
- First, grow a pure
N. gonorrhoeae isolate at 35Ā°C in 5% CO2 on suitable media for gonorrhea (such as chocolate agar or modified Thayer-Martin) for 24-48 hours, until obtain visible growth.
- āThen, prepare for shipment with three options. Make sure to submit the culture fresh (24-72 hr) at time of shipping to ensure it is viable when it arrives at MDL.āā
- To ship using an agar slant: Heavily inoculate a chocolate (or other suitable media for GC) slant with fresh growth. Incubate at 35Ā°C with 5% CO2 until you see visible growth (18 ā 24 hours is ideal). Then close cap tightly, pack, and ship at ambient temperature.
- āTo ship using an agar plate: Heavily inoculate a chocolate (or other suitable media for GC) plate with fresh growth. Incubate at 35Ā°C with 5% CO2 until you see visible growth (18 ā 24 hours is ideal). Then seal the plate lid tightly with parafilm and place the plate in zip lock biohazard bag, pack and ship at ambient temperature.
- āāTo ship using a frozen cryotube with TSB and 15% glycerol: Heavily inoculate a cryotube with fresh growth. Immediately place in a -60Ā°C or lower freezer. Once the isolate is fully frozen, ship the isolate on dry ice.
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- What is the shipping address?
āCalifornia Deparment of Public Health
Microbial Diseases Laboratory
ATTN: Bacterial Diseases Section
850 Marina Bay Parkwayā
Specimen Receiving, Room B-106
Richmond, CA 94804ā
- Who ācan submit isolates for testing?āāāā
Isolates are accepted from California Local Public Health Laboratories āoāānly. Isolates āāwill not be āāaccepted directly from hospitals or other healthcare facilities unless prior arrangements have been made by MDL and the applicable Local Public Health Laboratory. āāā
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- What is the turn-around-time?āāāā
Results of GC Etest will be available within 12 calendar days of isolate receipt. Expedited testing may be available with pre-approval from MDL. ā
- How do I get more informartion?
For more information on the GC Etest and submission criteria or instructions, please email
MDL.Submissions@cdph.ca.gov , or call the MDL Bacterial Diseases Section at (510) 412-3903.āā