TY - JOUR
T1 - Quantitative determination of gelatinase activity among enterococci
AU - Kanemitsu, K.
AU - Nishino, T.
AU - Kunishima, H.
AU - Okamura, N.
AU - Takemura, H.
AU - Yamamoto, H.
AU - Kaku, M.
PY - 2001
Y1 - 2001
N2 - Gelatinase, hemolysin and aggregation substance have all been reported to be virulence factors of enterococci. In this study, gelatinase production was investigated in isolates of Enterococcus faecalis (n = 93), E. faecium (n = 49) and E. avium (n = 36) recovered from hospitalized patients. Gelatinase was detected in 45% of E. faecalis isolates, but could not be detected in E. faecium and E. avium. Gelatinase activity was then measured by radial diffusion for the 42 gelatinase-positive E. faecalis isolates. To convert gelatinase activity into proteinase K activity, a standard curve was produced by placing different concentrations of proteinase K into wells in the gelatine plate. Gelatinase activity per E. faecalis colony ranged from 2.6 × 10-7 to 2.2 × 10-5 μg/ml, proportionate to the activity of proteinase K. An approximately 84-fold difference in gelatinase concentration was observed between the colony producing the highest amount and that producing the lowest amount. This method may be useful for determining the virulence of given isolates in relation to gelatinase production as it is quick, easy and inexpensive to perform.
AB - Gelatinase, hemolysin and aggregation substance have all been reported to be virulence factors of enterococci. In this study, gelatinase production was investigated in isolates of Enterococcus faecalis (n = 93), E. faecium (n = 49) and E. avium (n = 36) recovered from hospitalized patients. Gelatinase was detected in 45% of E. faecalis isolates, but could not be detected in E. faecium and E. avium. Gelatinase activity was then measured by radial diffusion for the 42 gelatinase-positive E. faecalis isolates. To convert gelatinase activity into proteinase K activity, a standard curve was produced by placing different concentrations of proteinase K into wells in the gelatine plate. Gelatinase activity per E. faecalis colony ranged from 2.6 × 10-7 to 2.2 × 10-5 μg/ml, proportionate to the activity of proteinase K. An approximately 84-fold difference in gelatinase concentration was observed between the colony producing the highest amount and that producing the lowest amount. This method may be useful for determining the virulence of given isolates in relation to gelatinase production as it is quick, easy and inexpensive to perform.
KW - Enterococci
KW - Gelatinase
KW - Radial diffusion assay
KW - Virulence factor
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U2 - 10.1016/S0167-7012(01)00283-4
DO - 10.1016/S0167-7012(01)00283-4
M3 - Article
C2 - 11566222
AN - SCOPUS:0034824305
VL - 47
SP - 11
EP - 16
JO - Journal of Microbiological Methods
JF - Journal of Microbiological Methods
SN - 0167-7012
IS - 1
ER -