Scottish MRSA Reference Manual

Scottish MRSA Reference Laboratory September 2006North Glasgow University Hospitals Division

SCOTTISH MRSA REFERENCE LABORATORYMANAGEMENT PROCEDURE

USER MANUAL

SOP NUMBER SMRSARL_UM_2006EDITION NUMBER 2.0DATE OF ISSUE September 2006

REVIEW INTERVAL Annually

AUTHOR (SIGNATURE) Dr. Donald Morrison

AUTHORISED BY (SIGNATURE) Dr. GFS Edwards

LOCATION OF COPIES Lab Managers Office, Q-PulseAREA OF APPLICATION All Users of SMRSARL

PERSONNEL CROSS REFERENCES

DOCUMENT REVIEW HISTORY

REVIEW DATE REVIEWED BY SIGNATUREAugust 2006 JM Hutchinson

Document name: SMRSARL_UM_2006 Version: 2.0 (September 2006)Approved by: G. Edwards Controlled Document

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History & Introduction

The Scottish MRSA Reference Laboratory (SMRSAL) was established in April 1997 in response to a rapid increase in the number of MRSA infections in Scottish hospitals. Between 1991 and 1995 about 500 MRSA infections were reported annually to the Scottish Centre for Infection and Environmental Health (SCIEH).In 1996 this rose markedly to 1500. Since the SMRSARL was established this upwards trend has continued with over 8000 reports in 2005.

The SMRSARL is commissioned by the Health Protection Scotland (HPS) which is part of the NHS National Services Scotland, and is based in the Microbiology Department of NHS Greater Glasgow at Stobhill Hospital. The laboratory provides a national MRSA reference service and accepts isolates from laboratories throughout Scotland. The service includes confirmation of MRSA status, antibiotic sensitivity monitoring, detection of toxin genes and epidemiological typing of strains. In addition SMRSARL provides advice on infection control issues, teaching and training of medical and technical staff and has an ongoing research and development program. SMRSARL collaborates with HPS to provide data on the national trends in MRSA epidemiology in Scotland. [www.smrsarl.scot.nhs.uk]


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Laboratory Hours

Normal Laboratory Hours

Monday - Friday 8.00 am - 5.00 pm

Out of hoursUnder exceptional circumstances tests will be performed outside the normal laboratory hours.

Services Available


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Tests performed on all isolates receivedPhenotypic confirmation of MRSA status is carried out on all isolates received. Isolates are phenotypically typed using biotype and antibiogram. Genotyping is currently by PCR-ribotyping (MSSA) and PFGE (MRSA). Phenotypic characteristics of Scottish MRSA are still being monitored.

Confirmation of MRSA statusIsolates giving equivocal results with the standard tests for species identification of Staphylococcus aureus are tested by PCR to detect the species specific nuc gene. Isolates with borderline resistance to methicillin are tested by oxacillin and cefoxitin E-tests and by PCR to detect the mecA gene.

Antibiotic susceptibility monitoringIsolates are tested for resistance to 22 antibiotics – (using VITEK and several others by disc diffusion). The resulting antibiogram is part of the phenotyping pattern; it is also used to monitor changing resistance patterns. Isolates with reduced susceptibility to mupirocin are further tested by PCR for the presence of the mupA gene to distinguish between high and low level mupirocin resistance.

VISA (Vancomycin intermediate resistant Staphylococcus aureus) screenAll referred isolates are screened, using a Break Point plate assay, for reduced susceptibility to vancomycin. Isolates positive on screening are further tested by E-test and broth microdilution MIC assay.

Epidemiological typingBy phenotypic typing (using biotype and antibiogram), more than 90% of MRSA isolates are assigned to known epidemic strains. Genotyping by PCR-ribotyping (PCR-R) and pulsed field gel electrophoresis (PFGE) is carried out on MSSA and MRSA respectively. PFGE type of MSSA and CNS is also performed if appropriate. PFGE is the more discriminatory technique and is particularly valuable in the investigation of localised outbreaks. PCR-R is a rapid method and although, less descrimatory, is useful for identifying clonal groups and can also be used for speciation of CNS.Sequenced based typing (MLST and spa typing) is carried out on selected isolates and will be used more widely in future.

Toxin Testing PCR tests are routinely available for detection of 9 staphylococcal toxin genes: five enterotoxin genes (sea, seb, sec, sed and see), the Document name: SMRSARL_UM_2006 Version: 2.0 (September 2006)Approved by: G. Edwards Controlled Document

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toxic shock sydrome toxin-1 (tst), two exofoliative toxins (eta and etb) and the Panton-Valentine Leukocidin gene. Other toxin genes are under evaluation.

Snapshot ProgrammeBecause hospitals referral policies differ, a "Snapshot" programme has been initiated, in collaboration with HPS, to obtain a more comprehensive picture of MRSA epidemiology in Scotland. In a rolling program, and by mutual agreement, each hospital is allocated a two week period when all "new" MRSA isolates are sent to the MRSA reference laboratory with epidemiological information.

Control of infection adviceAdvice on the various aspects of the control of MRSA infection is available.

Staphylococci other than MRSAMany of the tests performed in the Reference Laboratory are useful in the investigation of other Staphylococci. Epidemiological typing of MSSA and CNS by PFGE and species identification of CNS by phenotypic and genotypic (PCR based) methods will be undertaken on request.

Referral PolicySamples referred will be accepted from laboratories throughout Scotland. Advice and information will be provided to clinicians and agencies Scotland-wide.Document name: SMRSARL_UM_2006 Version: 2.0 (September 2006)Approved by: G. Edwards Controlled Document

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As a minimum, every laboratory should send specimens to the Reference Laboratory where confirmation that an isolate is an MRSA is necessary.

At the discretion of the sending laboratory, the following should be sent to the Reference Laboratory:

All outbreak/cross-infection isolates (MRSA, MSSA and CNS)

All blood cultures (MRSA and MSSA) as part of the EARSS surveillance programme

Isolates with unusual characteristics or those whose characteristics have changed

CNS requiring identification to the species level

All new MRSA isolates identified within a mutually agreed period (between 1 and 4 weeks) each year should also be submitted (Snapshot programme). The Reference Laboratory will be expected to work closely with SCIEH to obtain maximum value from this national surveilliance and to report back the results of this pilot to the commissioner in the Annual Report.

How to Obtain Services

Specimenspure cultures on agar slopes (preferably in bijoux bottles) or on swabs in transport medium.Document name: SMRSARL_UM_2006 Version: 2.0 (September 2006)Approved by: G. Edwards Controlled Document

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Request formsFill out the details on the request forms as completely as possible (request forms are available from SMRSARL directly or from the website, forms can be photocopied).

Postal addressSpecimens should be sent to:

Scottish MRSA Reference LaboratoryDepartment of Microbiology

Stobhill HospitalBalornock Road

Glasgow G21 3UW

Urgent specimensA "fast track" system is available for urgent specimens. Please telephone to request "fast tracking" of specimen and to notify when the specimen will arrive

Level of ServiceTurnaround Times

Strain Typing1 7-8 working days 2

PCR confirmation of MRSA status 5 working days


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Fast Track 1-3 working days 3

Notes

1. Includes phenotypic confirmation of MRSA status and genotypic typing.

2. Time from receipt of pure culture until report has been posted. Working days do not include weekends. Time refers to 95% of referrals.

3. Urgent specimens will be "fast tracked". From receipt of pure culture PCR confirmation of MRSA status can be performed in 1 day and PFGE typing in 3 days.

Teaching, Research & DevelopmentThe reference laboratory is committed to the teaching of medical and technical staff and has a continuing commitment to Research & Development activities relevant to the work of the laboratory. This includes collaborative work with microbiologists, Infection Control Nurses, scientists and biomedical scientists in referring hospitals.


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Areas of special interest:

Community MRSA

MRSA in animals

Antiseptic testing

Molecular characterisation of MRSA clones

Staphylococcus aureus with intermediate susceptibility to vancomycin (VISA)

Evaluation of media for MRSA screening

Problems, Complaints and Service Improvements

If any problems are encountered with the service or any matter for complaint arises, please contact the Director, Prof. Curtis Gemmell (0141-211-4654). In addition, suggestions for improvement of the service are welcomed


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Contacts

Prof. Curtis G. GemmellDirector

T: 0141-211-4654F: 0141-552-1524Email


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mailto:[email protected]


Dr. Giles EdwardsDeputy Director

T: 0141-201-3015F: 0141-558-5508Email

Dr. Donald MorrisonClinical Scientist

T: 0141-201-3030F: 0141-558-5508 Email

Ms Bonnie CosgroveBMS-3

T: 0141-201-3475F: 0141-558-5508Email

Postal address Scottish MRSA Reference Laboratory

Department of MicrobiologyStobhill HospitalBalornock Road

Glasgow G21 3UW


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Scottish MRSA Reference Manual

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