Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - agr Expression Precedes Escape of Internalized Staphylococcus aureus from the Host Endosome.
AU - Qazi, Saara N. A.
AU - Counil, Emilie
AU - Morrissey, Julie
AU - Rees, Catherine E. D.
AU - Cockayne, Alan
AU - Winzer, Klaus
AU - Chan, Weng C.
AU - Williams, Paul
AU - Hill, Philip J.
PY - 2001/11
Y1 - 2001/11
N2 - Staphylococcus aureus is a versatile pathogen capable of causing life-threatening infections. Many of its cell wall and exoproduct virulence determinants are controlled via the accessory gene regulator (agr). Although considered primarily as an extracellular pathogen, it is now recognized that S. aureus can be internalized by epithelial and endothelial cells. Traditional experimental approaches to investigate bacterial internalization are extremely time-consuming and notoriously irreproducible. We present here a new reporter gene method to assess intracellular growth of S. aureus in MAC-T cells that utilizes a gfp-luxABCDE reporter operon under the control of the Bacillus megaterium xylA promoter, which in S. aureus is expressed in a growth-dependent manner. This facilitates assessment of the growth of internalized bacteria in a nondestructive assay. The dual gfp-lux reporter cassette was also evaluated as a reporter of agr expression and used to monitor the temporal induction of agr during the MAC-T internalization process. The data obtained suggest that agr induction occurs prior to endosomal lysis and that agr-regulated exoproteins appear to be required prior to the release and replication of S. aureus within the infected MAC-T cells.
AB - Staphylococcus aureus is a versatile pathogen capable of causing life-threatening infections. Many of its cell wall and exoproduct virulence determinants are controlled via the accessory gene regulator (agr). Although considered primarily as an extracellular pathogen, it is now recognized that S. aureus can be internalized by epithelial and endothelial cells. Traditional experimental approaches to investigate bacterial internalization are extremely time-consuming and notoriously irreproducible. We present here a new reporter gene method to assess intracellular growth of S. aureus in MAC-T cells that utilizes a gfp-luxABCDE reporter operon under the control of the Bacillus megaterium xylA promoter, which in S. aureus is expressed in a growth-dependent manner. This facilitates assessment of the growth of internalized bacteria in a nondestructive assay. The dual gfp-lux reporter cassette was also evaluated as a reporter of agr expression and used to monitor the temporal induction of agr during the MAC-T internalization process. The data obtained suggest that agr induction occurs prior to endosomal lysis and that agr-regulated exoproteins appear to be required prior to the release and replication of S. aureus within the infected MAC-T cells.
U2 - 10.1128/IAI.69.11.7074-7082.2001
DO - 10.1128/IAI.69.11.7074-7082.2001
M3 - Journal article
VL - 69
SP - 7074
EP - 7082
JO - Infection and Immunity
JF - Infection and Immunity
SN - 0019-9567
IS - 11
ER -