Bacterial contamination of blenderized whole food and commercial enteral tube feedings in the Philippines.

Hospital-prepared tube feedings from four Philippine acute-care hospitals were analysed for microbial contamination. Two feedings were prepared on three separate days at each hospital. The tube feedings were either blended natural whole foods or a reconstituted commercial powdered nutritional product. Samples of each feeding were collected for coliform count and standard plate count at the time of preparation and at 1, 2 and 4 h after preparation after maintenance at room temperature (26-31 degrees C). At the time of preparation, mean coliform and standard plate counts for all samples were 10.3 most probable number per gram (MPN/g) and 7.4x10(4)colony-forming units per gram (cfu/g), respectively. Nine of 24 samples (38%) had coliform counts greater than 10 MPN/g, and 22/24 (92%) samples had standard plate counts greater than 10(3) cfu/g. There were significant increases in mean coliform and standard plate counts over 4 h (P=0.0005 and P=0.008, respectively). At 4 h after preparation, the mean coliform and standard plate counts were 18.2 MPN/g and 2.1x10(5) cfu/g, respectively. At this time, 18/24 (75%) samples had coliform counts greater than 10 MPN/g and 20/24 (83%) samples had standard plate counts greater than 10(5) cfu/g. The results of this study show that the microbial quality of the majority of the hospital-prepared enteral tube feedings analysed were not within published guidelines for safety.

Effect of high ambient temperature on contamination and physical stability of one-liter ready-to-hang enteral delivery systems.

The effect of high ambient temperature on the physical stability and bacterial contamination of 1-L, prefilled, closed enteral feeding systems was examined under simulated clinical conditions. One hundred Jevity Ready-to-Hang enteral feeding systems (Abbott Park, IL, USA) were placed in a 37 degrees C incubator for 24 h. The Ready-to-Hang formula containers were visually inspected at 0 and 24 h. Formula samples were collected from the containers at 24 h and plated on trypticase soy agar. Two samples had insignificant bacterial growth of one colony-forming unit per milliliter that was not demonstrated in repeat culture. No growth was observed for any other sample. Additional samples collected from the two apparently contaminated delivery sets showed no growth. No set showed signs of formula instability, such as coagulation, clumping, or curdling. These findings suggest that, even at a high ambient temperature of 37 degrees C, the risk of bacterial contamination or compromised physical integrity is very low with the use of 1-L, prefilled, closed enteral feeding systems.

Raman study of effect of phospholipid chain unsaturation on bilayer phase transitions.

Raman scattering has been used to study the gel to liquid-crystalline transition in several unsaturated mixed-chain, saturated mixed-chain, and unsaturated symmetric phospholipids. The results show that the large transition temperature widths in membranes containing unsaturated mixed-chain phospholipids in which the two acyl chains do not differ significantly in length are due mainly to the presence of the double bond and not to the asymmetry in the chains.