Cytological changes in chlorhexidine-resistant isolates of Pseudomonas stutzeri.
Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive analysis of X-ray (EDAX) have been used to examine chlorhexidine diacetate (CHA)-sensitive and -resistant isolates of Pseudomonas stutzeri and to determine the effects of CHA on the cells. Significant differences were observed in the structure, size and elemental composition of CHA-sensitive and -resistant cells. Treatment with CHA produced considerably greater changes in CHA-sensitive cells, with widespread peeling of the outer membrane, a substantial loss of cytoplasmic electron-dense material and extensive lysis. Cells from the resistant isolates showed no blebbing of the outer membrane and no structural damage. X-ray mapping confirmed the difference in CHA uptake between CHA-sensitive and CHA-resistant cells. It is proposed that changes in the outer membrane form a major mechanism of resistance to CHA in P. stutzeri.
Tattawasart
U
U
Welsh School of Pharmacy, and School of Molecular and Medical Biosciences, Cardiff University, Cardiff CF10 3XF, UK.
Hann
A C
AC
Maillard
J Y
JY
Furr
J R
JR
Russell
A D
AD
D002710:Chlorhexidine / Q000494:pharmacology*; D004396:Coloring Agents; D004202:Disinfectants / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004577:Electron Probe Microanalysis; D004602:Elements; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D011549:Pseudomonas / Q000737:chemistry / Q000187:drug effects* / Q000648:ultrastructure*
D004396:Coloring Agents; D004202:Disinfectants; D004602:Elements; D002710:Chlorhexidine