Friday, 2 December 2011

MRSA st398 identifiable in hospital by Tetracycline Resistance


That 's one way of identifying 'piggy' MRSA in hospital patients: the hard way - when human antibiotics don't work!

MRSA cc398 is the same strain as MRSA st398 - sometimes called "pig MRSA."


Abstract here


High prevalence of spa types associated with the clonal lineage CC398 among tetracycline-resistant methicillin-resistant Staphylococcus aureus strains in a Spanish hospital.


J Antimicrob Chemother. 2011 Nov 28;


Authors: Lozano C, Rezusta A, Gómez P, Gómez-Sanz E, Báez N, Martin-Saco G, Zarazaga M, Torres C


Abstract


OBJECTIVES: CC398 (67.3%), CC1 (11.5%), CC5 (11.5%) and CC8 (9.6%). A novel sequence type (ST), ST2077, belonging to CC398 was identified.


Most MRSA CC398 strains were typed as SCCmecV-agrI. In addition to ?-lactam resistance, isolates showed resistance to (gene/number of strains): tetracycline [tet(K)/36, tet(L)/8 and tet(M)/48], macrolides and lincosamides [erm(B)/6, erm(C)/25, erm(T)/2, msr(A)/msr(B)/4 and mph(C)/4], aminoglycosides [aac(6')-Ie-aph(2')-Ia/8, ant(4')-Ia/13 and aph(3')-IIIa/15], trimethoprim [dfrS1/2 and dfrK/3] and mupirocin
(mupA/3). 


Strains investigated for mutations mediating quinolone resistance revealed an S80F exchange in GrlA and different changes in GyrA. Three strains were Panton-Valentine leucocidin-positive (ST8 and ST94) and 41 strains were cna-positive. All MRSA isolates were negative for the genes tst, eta, etb and etd.


Conclusions
Tetracycline resistance could be a good marker for MRSA CC398, although this resistance can also be found in other lineages.


PMID: 22127589 [PubMed - as supplied by publisher]