Minimally Invasive Mitral Valve Surgery II: Surgical Technique and Postoperative Management.

Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery

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

Capsular profiling of the Cronobacter genus and the association of specific Cronobacter sakazakii and C. malonaticus capsule types with neonatal meningitis and necrotizing enterocolitis

Background: Cronobacter sakazakii and C. malonaticus can cause serious diseases especially in infants where they are associated with rare but fatal neonatal infections such as meningitis and necrotising enterocolitis. Methods: This study used 104 whole genome sequenced strains, covering all seven species in the genus, to analyse capsule associated clusters of genes involved in the biosynthesis of the O-antigen, colanic acid, bacterial cellulose, enterobacterial common antigen (ECA), and a previously uncharacterised K-antigen. Results: Phylogeny of the gnd and galF genes flanking the O-antigen region enabled the defining of 38 subgroups which are potential serotypes. Two variants of the colanic acid synthesis gene cluster (CA1 and CA2) were found which differed with the absence of galE in CA2. Cellulose (bcs genes) were present in all species, but were absent in C. sakazakii sequence type (ST) 13 and clonal complex (CC) 100 strains. The ECA locus was found in all strains. The K-antigen capsular polysaccharide Region 1 (kpsEDCS) and Region 3 (kpsMT) genes were found in all Cronobacter strains. The highly variable Region 2 genes were assigned to 2 homology groups (K1 and K2). C. sakazakii and C. malonaticus isolates with capsular type [K2:CA2:Cell+] were associated with neonatal meningitis and necrotizing enterocolitis. Other capsular types were less associated with clinical infections. Conclusion: This study proposes a new capsular typing scheme which identifies a possible important virulence trait associated with severe neonatal infections. The various capsular polysaccharide structures warrant further investigation as they could be relevant to macrophage survival, desiccation resistance, environmental survival, and biofilm formation in the hospital environment, including neonatal enteral feeding tubes

Minimally Invasive Mitral Valve Surgery III: Training and Robotic-Assisted Approaches.

Minimally invasive mitral valve operations are increasingly common in the United States, but robotic-assisted approaches have not been widely adopted for a variety of reasons. This expert opinion reviews the state of the art and defines best practices, training, and techniques for developing a successful robotics program

The molecular characterisation of Escherichia coli K1 isolated from neonatal nasogastric feeding tubes

Background: The most common cause of Gram-negative bacterial neonatal meningitis is E. coli K1. It has a mortality rate of 10–15%, and neurological sequelae in 30– 50% of cases. Infections can be attributable to nosocomial sources, however the pre-colonisation of enteral feeding tubes has not been considered as a specific risk factor. Methods: Thirty E. coli strains, which had been isolated in an earlier study, from the residual lumen liquid and biofilms of neonatal nasogastric feeding tubes were genotyped using pulsed-field gel electrophoresis, and 7-loci multilocus sequence typing. Potential pathogenicity and biofilm associated traits were determined using specific PCR probes, genome analysis, and in vitro tissue culture assays. Results: The E. coli strains clustered into five pulsotypes, which were genotyped as sequence types (ST) 95, 73, 127, 394 and 2076 (Achman scheme). The extra-intestinal pathogenic E. coli (ExPEC) phylogenetic group B2 ST95 serotype O1:K1:NM strains had been isolated over a 2 week period from 11 neonates who were on different feeding regimes. The E. coli K1 ST95 strains encoded for various virulence traits associated with neonatal meningitis and extracellular matrix formation. These strains attached and invaded intestinal, and both human and rat brain cell lines, and persisted for 48 h in U937 macrophages. E. coli STs 73, 394 and 2076 also persisted in macrophages and invaded Caco-2 and human brain cells, but only ST394 invaded rat brain cells. E. coli ST127 was notable as it did not invade any cell lines. Conclusions: Routes by which E. coli K1 can be disseminated within a neonatal intensive care unit are uncertain, however the colonisation of neonatal enteral feeding tubes may be one reservoir source which could constitute a serious health risk to neonates following ingestion

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

Time budget and habitat use patterns of marbled godwits (Limosa fedoa beringiae) breeding on the Alaska Peninsula

Diurnal time budgets and habitat use patterns of breeding Ugashik marbled godwits (Limosa fedoa beringiae) were studied on the north-central portion of the Alaska Peninsula during spring and summer 1995-1996. Marbled godwits were observed from blinds and behaviors were described for the four phases of the breeding season: pair-formation, egg-laying, incubation and post-hatching. During pair-formation, males spent the majority of time performing flight displays (40.2%), most notably the ceremonial flight (30.7%). Males spent 34.3% of the egg-laying period guarding their mates probably to reduce the threat of cuckoldry. Females incubated during the daytime and males incubated at night. Off-duty males were engaged in maintenance activities (49.4%) or were alert/erect (22.7%). Four marbled godwit nests and the first newly hatched, downy marbled godwit chicks ever recorded in Alaska were found within the study site. One parent guarded the chicks which allowed the other to forage in nearby wetlands. Males performed male-exit flight as they prepared to depart for coastal staging lagoons approximately three weeks after their chicks hatched. Interspecific and intraspecific hostility peaked during the post-hatching period although aggressiveness towards neighboring shorebirds decreased. Godwits may benefit from the aggressive nature of some neighboring shorebirds and more timid species may receive a similar benefit from nesting close to godwit semi-colonies. The scattering of nests in loose semi-colonies may reduce predation by offering both nest concealment and group defense. Cover types and microhabitat characteristics were compared between sites used by marbled godwits ("present") and paired sites where no godwits were observed throughout the breeding season ("absent"), and among sites used for broodrearing, foraging, ground display and nesting. Logistic regression models predicted the probability of godwit occurrence or the probability of a godwit broodrearing, foraging, displaying or nesting based upon significant site features. Results indicate that different cover types were used for broodrearing, foraging, ground display and nesting, and cover types differed between present and absent sites. Microhabitat characteristics were different between present and absent sites, and they varied among the different use sites. The odds of finding a godwit at a site or the odds of finding a godwit broodrearing, foraging, displaying or nesting changed with changes in the significant microhabitat characteristics. As the percent shrub cover increased the odds of finding a brood or a nest increased 2.65-fold and 1.95-fold, respectively. The vegetation at broodrearing sites was taller (1.6 dm) than the vegetation at the other use sites, while the vegetation at nest sites was considerably shorter (1.3 dm) and denser. The probability of finding a godwit foraging increased with increasing forb cover and water depth, and decreasing shrub and moss cover and site roughness. Godwits used the periphery of wetlands for ground display. These grassy areas were typically transition zones between the wetland itself and the drier shrub communities

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