Evaluation of the Appropriateness of Previously Developed Escherichia coli Biotype I Surrogates as Predictors of Non-O157:H7 Shiga Toxin-Producing E. coli in Beef Processing

Non-O157 Shiga-toxin producing Escherichia coli (STECs) serovars O145:NM, O45:H2, O26:H11, O103:H11, O111 (organism was originally ordered from American Type Culture Collection (ATCC) under accession # BAA-2217, and has since then been reclassified as O147, see Appendix), O121:H19, and E. coli biotype I surrogates were individually cultured in tryptic soy broth (TSB) at 37°C for 18 hours. Rifampicin-resistant (rif-resistant) surrogates were compared to the parent strains listed above. Stationary phase and acid-adapted organisms were each transferred into phosphate buffer saline (PBS) acidified with L-lactic acid at pH 2.5, 3.0, and 3.5, and enumerated for survivors following a 2-hour exposure time. In order to construct a thermal destruction curve, organisms were transferred into a capillary tube, flame sealed, submerged in a water bath at 55, 60 and 65 ± 0.5°C, and enumerated for survivors. For freezing (-20 ± 0.5°C) and refrigerated (4 ± 0.5°C) storage, bacterial strains were enumerated on days 0, 7, 14, 21, 28, 60, and 90 to determine the response to freezing and refrigerated storage. Growth curves of E. coli biotype I surrogates (parent and rif-resistant) were similar to those of STECs throughout the evaluation. For acid resistance, acid-adapted organisms at pH 3.0 showed initial log reductions (CFU/ml) ranging from 1.7-2.5, where organism O26:H11 had the greatest log reduction (2.5). After 2 hours exposure time, reductions ranged from 5.1-7.4 log CFU/ml. D-values were calculated for each organism at 55, 60 and 65 ± 0.5°C. Acid-adapted organisms at 65°C had D-values ranging from 0.13-0.64 min, with a rif-resistant E. coli biotype I surrogate (BAA-1429 rif) having the highest D-value at this temperature. For the response to refrigeration and freezing temperatures, there were no notable trends or patterns observed, and no one single E. coli biotype I surrogate represented all of the non-O157 STECs. Organisms were analyzed individually and in sets (surrogates, rif-resistant surrogates and STECs) to represent a mean. Analyzing the organisms in sets eliminated certain individual strain-to-strain variation, and showed fewer differences (P < 0.05). Surrogates analyzed as a mean of the five strains indicate they may be best utilized in combination to represent all six of the non-O157 STECs

Biofilm formation on enteral feeding tubes by Cronobacter sakazakii, Salmonella serovars and other Enterobacteriaceae

WHO (2007) recommended that to reduce microbial risks, powdered infant formula should be reconstituted with water at temperatures >70 °C, and that such feeds should be used within 2 h of preparation. However, this recommendation does not consider the use of enteral feeding tubes which can be in place for more than 48 h and can be loci for bacterial attachment. This study determined the extent to which 29 strains of Cronobacter sakazakii, Salmonella serovars, other Enterobacteriaceae and Acinetobacter spp. can adhere and grow on enteral feeding tubes composed of polyvinyl chloride and polyurethane. The study also included silver-impregnated tubing which was expected to have antibacterial activity. Bacterial biofilm formation by members of the Enterobacteriaceae was ca. 105-106 cfu/cm after 24 h. Negligible biofilm was detected for Acinetobacter gensp. 13; ca. 10 cfu/cm, whereas Cr. sakazakii strain ATCC 12868 had the highest biofilm cell density of 107 cfu/cm. Biofilm formation did not correlate with capsule production, and was not inhibited on silver-impregnated tubing. Bacteria grew in the tube lumen to cell densities of 107 cfu/ml within 8 h, and 109 cfu/ml within 24 h. It is plausible that in vivo the biofilm will both inoculate subsequent routine feeds and as the biofilm ages, clumps of cells will be shed which may survive passage through the neonate's stomach. Therefore biofilm formation on enteral feeding tubes constitutes a risk factor for susceptible neonates

Use of Palmaz stents in a newborn with congenital aneurysms and coarctation of the abdominal aorta

Anomalies of the abdominal aorta are rare in the pediatric population limiting the reported knowledge base from which management decisions can be made. A 3-week-old male with congenital abdominal aortic coarctation and multiple aneurysms presented with malignant hypertension. We report the safe deployment of overlapping Palmaz stents using a 4-French catheter delivery system with significant relief of the coarctation gradient and restoration of adequate renal perfusion. © 2006 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55844/1/20749_ftp.pd

Minimally Invasive Mitral Valve Surgery I: Patient Selection, Evaluation, and Planning.

Widespread adoption of minimally invasive mitral valve repair and replacement may be fostered by practice consensus and standardization. This expert opinion, first of a 3-part series, outlines current best practices in patient evaluation and selection for minimally invasive mitral valve procedures, and discusses preoperative planning for cannulation and myocardial protection

Rapid in situ imaging and whole genome sequencing of biofilm in neonatal feeding tubes: a clinical proof of concept

The bacterial flora of nasogastric feeding tubes and faecal samples were analysed for a low-birth weight (725g) neonate EGA 25 weeks in intensive care. Samples were collected at age 6 and 8 weeks of life. Optical coherence tomography (OCT) was used to visualise bacterial biofilms inside the nasogastric feeding tubes. The biofilm was heterogeneously distributed along the tube lumen wall, and had a depth of up to 500µm. The bacterial biofilm and faecal samples included Enterococcus faecalis and Enterobacter hormaechei. Representative strains, recovered from both feeding tubes and faecal samples, were whole genome sequenced using Illumina, Mi-Seq, which revealed indistinguishable strains, each with less than 28 SNP differences, of E. faecalis and E. hormaechei. The E. faecalis strains were from two sequence types (ST191 and ST211) and encoded for a number of traits related to biofilm formation (BopD), adherence (Epb pili), virulence (cps loci, gelatinase, SprE) and antibiotic resistances (IsaA, tetM). The E. hormaechei were all ST106, and encoded for blaACT-15 β–lactamase and fosfomycin resistance (fosA). This proof of concept study demonstrates that bacterial flora within the neonatal feeding tubes may influence the bacterial colonisation of the intestinal tract and can be visualised nondestructively using OCT

Mineralogy

The power of mineralogical analysis as a descriptive or predictive technique stems from the fact that only a few thousand minerals are known to occur in nature as compared to several hundred thousand inorganic compounds. Further, all of the known minerals have specific stability ranges in pressure, temperature, an composition. A specific knowledge of the mineralogy of a planets surface or interior therefore allows one to characterize the present or past conditions under which the minerals were formed or have existed. For the purposes of this paper, a slightly broader definition of mineralogy was adopted by including not only crystalline materials found on planetary surfaces, but also ices and classes that can benefit from in situ types of analyses. Both visual examination and the various spectroscopies available for robotic probes to planetary surfaces are discussed