Impact of daily octenidine skin washing versus nonwashing on antiseptic tolerance of coagulase-negative staphylococci in two neonatal intensive care units with different skin cleansing practices.

Background: There is wide variation in practices regarding routine bathing/washing of babies in neonatal intensive care units (NICUs). Evidence is lacking as to the benefit of routine antiseptic washes for reducing infection. We aimed to compare the antiseptic tolerance of Coagulase Negative Staphylococci (CoNS) within two UK NICUs with very different approaches to skin washing. Methods: We compared antiseptic susceptibility of CoNS isolated from skin swabs of neonates admitted to the Norfolk and Norwich University Hospital (NNUH) NICU in December 2017-March 2018 with those isolated in the Bradford Royal Infirmary (BRI) NICU in January-March 2020. The NNUH does not practise routine whole-body washing whereas BRI practises daily whole-body washing from post-menstrual age 27 weeks using Octenisan wash lotion (0.3% octenidine; 1 minute contact time before washing off with sterile water). A total of 78 CoNS isolates from BRI and 863 from the NNUH were tested for susceptibility against the antiseptics octenidine (OCT) and chlorhexidine (CHX). Results: Isolates from the BRI with practice of routine washing did not show increased antiseptic tolerance to OCT or CHX. Isolates from the NNUH which does not practise routine whole-body washing and rarely uses octenidine, were comparatively less susceptible to both CHX and OCT antiseptics. Conclusions: Daily whole-body skin washing with OCT does not appear to select for CoNS isolates that are antiseptic tolerant towards OCT and CHX. There remains considerable uncertainty about the impact of different antiseptic regimes on neonatal skin microbiota, the benefit of routine washing, and the development of antiseptic tolerance in the NICU.

Viscoelastic properties of waxy and nonwaxy rice flours, their fat and protein-free starch, and the microstructure of their cooked kernels.

Physicochemistry and structural studies of two types of japonica rice, low amylose Calmochi-101 (CM101) and intermediate amylose M-202 (M202), were conducted to determine similarities and differences between the rices perhaps attributable to amylose content differences. The rheological behavior of the gelation and pasting processes of flours and starches was determined with high accuracy and precision using a controlled stress rheometer. Fat and protein, although minor constituents of milled rice, were shown to have significant effects on the physicochemical and pasting properties of starches and flours. Removal of protein and lipids with aqueous alkaline or detergent solutions caused lower pasting temperatures and higher overall viscosity in both starches, compared with their respective flours. There was less viscosity difference between M202 flour and its starch when isolated by enzymatic hydrolysis of protein. The protease did not reduce internally bound lipids, suggesting that fats help to determine pasting properties of rice flours and their respective starches. Structural integrity differences in individual granules of waxy and nonwaxy rice flours, starches, and whole raw, soaked, and cooked milled grain were revealed by fracture analysis and scanning electron microscopy. Calmochi 101 and M202 did not differ in weight-averaged molar mass (Mw) and root-mean-square radii (Rz) between flours and starches, as determined by high-performance size exclusion chromatography (HPSEC) and multiple-angle laser light scattering (MALLS) (Park, I.; Ibanez, A. M.; Shoemaker, C. F. Starch 2007, 59, 69-77).

Microbiological assay-trienzyme procedure for total folates in cereals and cereal foods: collaborative study.

In 1996, U.S. Food and Drug Administration regulations mandated the fortification of enriched cereal-grain products with folic acid, thereby emphasizing the need for validated methods for total folates in foods, particularly cereal products. The AOAC Official Methods (944.12, 960.46) currently used for the analysis of folate in foods for compliance purposes are microbiological methods. When the fortification regulations were finalized, no Official AOAC or Approved AACC methods for folate in cereal-grain products were in place. The AOAC Official Method (992.05) for folic acid in infant formula does not incorporate important improvements in the extraction procedure and was not considered suitable for the analysis of folates in foods in general. A microbiological assay protocol using a trienzyme extraction procedure was prepared and submitted for comments to 40 laboratories with recognized experience in folate analysis. On the basis of comments, the method was revised to have the conjugase (gamma-glutamyl-carboxy-peptidase) treatment follow a protease treatment, to include the use of cryoprotected inoculum, and to include the spectroscopic standardization of the standard and optional use of microtiter plates. Thirteen laboratories participated in a collaborative study of 10 required and 10 optional cereal-grain products, including flour, bread, cookies, baking mixes, and ready-to-eat breakfast cereals. The majority of the participating laboratories performed the assay by the standard test tube method; others used the microtiter plate modification for endpoint quantitation with equal success. For the required products, the relative standard deviation between laboratories (RSD(R)) ranged from 7.4 to 21.6% for 8 fortified (or enriched) products compared with expected (Horwitz equation-based) values of 11-20%. RSD(R) values were higher (22.7-52.9%) for 2 unfortified cereal-grain products. For the optional products, the RSD(R) ranged from 1.8 to 11.2% for 8 fortified products. RSD(R) values were higher (27.9-28.7%) for 2 unfortified cereal-grain products. Based on the results of the collaborative study, the microbiological assay with trienzyme extraction is recommended for adoption as Official First Action.