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Staphylococcus Reference Section

Please see our referral criteria for guidelines on submission of Staphylococcus aureus isolates (including MRSA) to the Reference Laboratory.

Phage typing of S. aureus (WHO reference/collaborating centre)

S. aureus strains are characterised using the following 23 international and several local experimental phages.

At Routine Test Dilution (RTD) At 100 x RTD and 1000 x RTD
International phages International phages
29, 52, 52A, 79, 80
3A, 3C, 55, 71, 95
6, 42E, 47, 53, 54
75, 77, 83A, 84, 85
81, 94, 96		 29, 52, 52A, 79, 80
3A, 3C, 55, 71, 95
6, 42E, 47, 53, 54
75, 77, 83A, 84, 85
81, 94, 96
Experimental phages Experimental phages
D16, 47A, 27, 33 88A, 90, 83C, 932

Phage reactions are graded as follows:

  At RTD At 100 x RTD and 1000 x RTD
1-5 plaques 1 1
6-19 plaques 2 2
20-49 plaques 3 3
50 or more plaques 8 8
confluent lysis Not applicable 9
inhibition reaction Not applicable 0

For further information please contact us or see Parker MT (1972) Phage typing of Staphylococcus aureus. In Methods in Microbiology 7B (Norris, JR & Ribbons DW Eds) pp1-28. Academic Press, London & New York

Molecular typing (PFGE) for epidemiological investigations:

PFGE-based typing of MSSA and MRSA is available to assist with suspected cross-infection and epidemiological investigations. Please contact us for further information.

To date, 17 different epidemic types of MRSA have been described (EMRSA-1 to 17).
Currently, 2 types are widely distributed throughout England: EMRSA-15 and 16 which can be discriminated using PFGE.

At present we recognise

  • 27 sub-types of EMRSA-15 1
  • 33 sub-types of EMRSA-16

1. O'Neill GL, Murchan S, Gil-Setas A, Aucken HM. Identification and characterization of phage variants of a strain of epidemic methicillin-resistant Staphylococcus aureus (EMRSA-15). J Clin Microbiol 2001; 39:1540-1548.


PCR-based detection of staphylococcal toxin genes in isolates from clinical and food-related disease:

The following virulence genes are screened for using multiplex PCR:

  • Toxic shock syndrome toxin ( tst)
  • Enterotoxins ( sea, seb, sec, sed, see, seg, seh, sei and sej)

For the above, our studies have shown a 99% correlation with gene detection and expression.

  • Panton-Valentine leukocidin ( lukS-PV / lukF-PV) 2
    - particularly associated with abscesses, furunculosis and necrotising pneumonia
  • Exfoliatins ( eta, etb and etd 3)
    - particularly assoicated with scalded skin syndrome and impetigo

2. CDR weekly Volume 13 number 15. 10 April (pages 5-6)
3. Yamaguchi T, Nishifiji K, Sasaki M et al. Identification of the Staphylococcus aureus etd pathogenicity island which encodes a novel exfoliative toxin, ETD, and EDIN-B. Infect Immun 2002; 70:5835-5845

Phenotypic and genotypic identification of Coagulase-negative staphylococci.

This service uses the API ID32STAPH kit to provide preliminary data and isolates are subsequently tested using PCRs specific for S. epidermidis, S. haemolyticus and S. hominis as appropriate.
For epidemiological purposes, molecular ( PFGE-based) fingerprinting of multiple CNS isolates is available on request.


Last reviewed: 4 September 2008