INVESTIGADORES
RENNA Maria Sol
artículos
Título:
Comparison of phenotypic tests for detecting penicillin G resistance with presence of blaZ gene in Staphylococcus aureus isolated from bovine intramammary infections.
Autor/es:
RUSSI N.B; MAITO J; DIESER S; RENNA M.S; SIGNORINI M.L; CAMUSSONE MC; NEDER V; POL M; TIRANTE L; ODIERNO LM; CALVINHO LF
Revista:
Journal of Dairy Research
Editorial:
CAMBRIDGE UNIV PRESS
Referencias:
Lugar: Cambridge; Año: 2015 vol. 5 p. 1 - 5
ISSN:
0022-0299
Resumen:
Few studies have described the relationship between genotypic and phenotypic methods for detecting
penicillin resistance in Staphylococcus aureus isolated from bovine intramammary infection
(IMI). Six phenotypic methods for penicillinase detection were compared with a genotypic
method testing the presence of the â-lactamase gene blaZ in Staph. aureus (n = 150) isolated from
bovine IMI. Highest sensitivities and specificities were observed for disk diffusion (DD) (93 and
97·4%), minimum inhibitory concentration (MIC) (90·3 and 97·4%), Cefinase? (85·9 and 97·4%)
and Diatabs? (85·7 and 98·7%). The estimated cut-off points estimated in the present study can
be considered close to the ones indicated by CLSI (2013). The molecular detection of blaZ gene
is the only method that may indicate the real or potential capacity of producing â-lactamase in
Staph. aureus. Considering that from a clinical standpoint a false negative result from a phenotypic
test is the most unfavourable situation, a combination of standard DD with Diatabs? or Cefinase?
should be performed by routine mastitis laboratories to minimise false negative results.