Effect of siliconized latex urinary catheters on the activity of carbapenems against Pseudomonas aeruginosa strains with defined mutations in ampC, oprD, and genes coding for efflux systems.

The decreased activity of carbapenems against Pseudomonas aeruginosa in the presence of eluates from siliconized latex urinary catheters is related to the loss of OprD and the expression of a new outer membrane protein (OMP). To understand this phenomenon, the activity of carbapenems and quinolones against P. aeruginosa strains, some producing AmpC beta-lactamase (BL), OprD, MexA-MexB-OprM and MexE-MexF-OprN, were determined in Mueller-Hinton broth (MH) and in MH-containing eluates.

Zinc eluted from siliconized latex urinary catheters decreases OprD expression, causing carbapenem resistance in Pseudomonas aeruginosa.

The activities of carbapenems against Pseudomonas aeruginosa decreased in the presence of siliconized latex urinary catheters (SLUCs). This effect was associated with the loss of OprD. The zinc that eluted from SLUCs is responsible for this phenomenon.

Resistance of Pseudomonas aeruginosa to imipenem induced by eluates from siliconized latex urinary catheters is related to outer membrane protein alterations.

The activity of imipenem against Pseudomonas aeruginosa HUS-3 decreased by 16 times in the presence of substances eluted from siliconized latex urinary catheters (SLUCs). SLUCs did not inactivate imipenem or increase beta-lactamase activity. The outer membrane of P.

Effects of ethanol on the inner layers of chick retina during development.

Optic nerve hypoplasia is an important malformation of the fetal alcohol syndrome whose teratogenic mechanisms are unknown. In our experimental model we have quantified the concentration of ethanol and acetaldehyde in the retina and vitreous humor of the developing chick. The effect of ethanol alone during retinal development was analyzed by conventional histological techniques and by immunostaining.