Feed presentation options in Swine early fattening mitigates Salmonella shedding and specifically modulates the faecal microbiota.

AIMS: The object of this study was to determine the impact of only modifying the processing and/or particle size of pig feed on Salmonella shedding and faecal microbiota. METHODS AND RESULTS: Pigs were fed a diet that varied only by their processing (pellet or mash) and their particle size (500, 750 or 1250 µm) for 21 days. Salmonella detection in faeces and seroconversion were determined. Faecal microbiota was assessed by Ion Torrent amplicon sequencing and real-time PCR. Significantly fewer pigs (P < 0·05) shed Salmonella in the groups fed mash 500 (1) and mash or pellet 1250 (5 each) compared to the commercial reference group (15) fed pellet 500. Both mash processing and large particle size raised the proportion and number of bacteria from the Bifidobacterium genus in the faecal microbiota of the pigs. Thirteen other taxa significantly varied (P < 0·0005) with feed presentation. CONCLUSION: Mash processing and/or large particle size in pig feed reduces Salmonella shedding prevalence and promotes beneficial populations of digestive microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first to demonstrate a difference in Salmonella shedding through only modifying pig feed presentation and is the first to extensively describe modifications of faecal microbiota.

Transtibial amputee gait with the unity suspension system.

Study Design: Experimental study.Objectives: Research is lacking on the Unity suspension system's effect on gait performance. The purpose of this study was to evaluate the effects of the Unity elevated vacuum system on level walking performance while the vacuum was active (ON) and inactive (OFF).Methods: Twelve unilateral transtibial amputees were fit with the Ossur elevated vacuum suspension system (Unity) and Pro-flex XC foot. After one month accommodation period, 3D motion analysis was performed using the CAREN-Extended system. Temporal-spatial, kinematics, and kinetics were examined during level walking to understand the effect of the elevated vacuum, separate trials were completed with the vacuum active (ON) or inactive (OFF).Results: Significant differences were found between vacuum conditions (ON and OFF) for some temporal-spatial gait parameters, but differences were very small and may not be clinically significant. Differences between vacuum conditions on most kinetic and kinematic gait parameters were also low. However, step length symmetry between intact and prosthetic limbs improved with active elevated vacuum (ON).Conclusions: Elevated vacuum suspension's effect on level walking gait is small if a well-fitting liner-based socket is provided.Implications for rehabilitationStep length symmetry between intact and prosthetic limbs improved with an active vacuum system.Differences between vacuum conditions on most gait parameters were small during level walking.Subjective feedback showed improved proprioception and comfort with an active vacuum system.

Risk factors for falling among community-dwelling seniors using home-care services: an extended hazards model with time-dependent covariates and multiple events.

The identification of risk factors for falls in longitudinal studies becomes difficult because of exposures that change during the follow-up and also because individual subjects may experience an event more than once. These issues have been neglected and improper statistical techniques have been used. The typical approaches have been to report the proportion of fallers or the time to first fall. Both avoid the underlying assumption of independence between events and discard pertinent data. We review the existing methods and propose a Cox hazards extension. We exemplify it in the study of potential risk factors associated with all falls in 959 seniors. Finally, we compare the results of the proposed Wei, Lin, & Weissfeld (WLW) method with those of several other techniques. Stable exposure variables measured at baseline and updated time-varying exposures include socio-demographic characteristics, BMI, nutritional risk, alcohol consumption, home hazards, gait and balance, and medications. Results demonstrate that the usual methods of analyzing risk factors for falling are inappropriate, as they produce considerable biases relative to the WLW model using time-dependent covariates. Results also show that modeling for first events may be inefficient, given that the risk of occurrence varies between falls.

Impact of mash feeding versus pellets on propionic/butyric acid levels and on total load in the gastrointestinal tract of growing pigs.

Feed characteristics may influence the bacterial community composition and metabolic activities in the pig gastrointestinal tract, known to be associated with positive effects on the gut. Use of mash feed is associated with reduced excretion, but little is known of its effect on the population or of the mechanism of action. Our objectives were to assess the effect of feed texture combined with feed particle size on VFA profiles and levels, total count, and the presence of genes encoding virulence factors of pathogenic strains in the digestive tract along with their impact on pig performance of fattening pigs. Pigs ( = 840) on a commercial farm received mash or pellet diets of different particle sizes during the fattening period. Caecal and colon contents from 164 pigs were sampled at the slaughterhouse for enumeration of by quantitative PCR (qPCR) and for VFA quantification by capillary gas chromatography. The gene was used to enumerate total . Improved pig performances associated with pellet texture and a 500-µm size were observed. Caecal ( = 0.02) and colon ( < 0.01) propionic acid concentrations were lower for pigs receiving pellet rather than mash feed. Similarly, caecal ( = 0.01) and colon ( < 0.001) butyric acid concentrations were also lower for pigs receiving pellet rather than mash feed, as determined by capillary gas chromatography. Moreover, caecal ( = 0.03) and colon ( < 0.001) butyric acid concentrations were higher for pigs receiving a feed with a 1,250-µm particle size rather than a 500-µm particle size. On the other hand, total caecal and colon levels were higher for pigs receiving pellet feed than for those receiving mash feed. For total enumeration, caecal ( < 0.01) and colon ( < 0.01) gene copies were higher for pigs receiving pellet rather than mash feed. No effect of particle size on fatty acid concentrations or on numbers was observed. Virulence gene quantification revealed no trend. Taken together, results showed that mash feed is associated with lower growth performance but with favorable intestinal changes linked to VFA levels and reduction in the intestine.

Circadian variation of postprandial lipemia.

The goal of the present study was to assess the influence of mealtime on postprandial lipemia. Thirteen healthy subject aged 19-32 y were given the same meal at night (0100) or during the day (1300) in random order: the meal contained 40% of estimated daily energy expenditure. Blood samples were drawn at baseline and hourly for 8 h after the meal. Serum total cholesterol, very-low-density-lipoprotein cholesterol (VLDL-C), low-density-lipoprotein cholesterol (LDL-C), high-density-lipoprotein cholesterol (HDL-C), triacylglycerols, VLDL-triacylglycerols, apolipoprotein (apo) A-I, and apo B were measured at each time point. In a subgroup of seven subjects a control fasting reference line was measured according to the same nocturnal and diurnal time schedule. The mean postprandial concentrations of triacylglycerol (P < 0.001), VLDL-triacylglycerol (P < 0.001), and VLDL-C (P < 0.001) were higher at night than during the day. In contrast, mean cholesterol (P < 0.01), LDL-C (P < 0.01), HDL-C (P < 0.001), apo A-I (P < 0.001), and apo B (P < 0.001) concentrations were lower after the night meal than after the day meal. The magnitude of the postprandial response was estimated by the area between the fasting and postprandial curves. The triacylglycerol and VLDL-triacylglycerol responses were not significantly different between night and day. The VLDL-C (P < 0.01) response was greater and LDL-C (P < 0.0001) and HDL-C (P < 0.01) responses were lower at night than during the day. These results indicate that circadian factors specifically affect serum cholesterol transport. Apo B (P < 0.01) and apo A-I (P < 0.01) responses followed LDL-C and HDL-C changes during the day but were dissociated from lipoprotein responses at night, suggesting that circadian apolipoprotein regulation is dissociated from that of serum lipids. The results of the present study indicate that postprandial lipid, lipoprotein, and apolipoprotein concentrations are affected by circadian factors.

Influence of mental stress and circadian cycle on postprandial lipemia.

BACKGROUND: Mental stress produces alterations in serum lipids and lipoproteins. OBJECTIVE: The objective was to assess the effect of mental stress during the day and night on postprandial lipoproteins. DESIGN: Fourteen healthy subjects aged 26.6 +/- 5.0 y were given randomly the same meal either at night (0100) or during the day (1300), with or without (control session) a mental stress challenge. The meal contained 40% of estimated daily energy needs. The mental task was performed on a computer and consisted of a task of choice reaction. Blood samples were drawn at baseline and hourly for 7 h after the meal. RESULTS: Urinary epinephrine concentrations were higher (P < 0.012) during the mental task than during the control sessions. Repeated-measures analysis of variance showed that mean postprandial triacylglycerol concentrations were significantly higher (P < 0.02) and total cholesterol (P < 0.0001) and HDL-cholesterol concentrations were significantly lower (P < 0.0001) at night than during the day. The mean postprandial VLDL-triacylglycerol concentration was significantly higher (P < 0.04) during the mental task than during the control sessions. Similarly, the VLDL-cholesterol response, calculated as the area under the postprandial curve, was significantly greater (P < 0.02) during the mental task than during the control sessions. There was no interaction between mental stress and nyctohemeral cycle on postprandial lipoprotein responses, suggesting that both indexes act independently on postprandial lipid metabolism. CONCLUSIONS: Mental stress is associated with increased concentrations of postprandial triacylglycerol-rich lipoprotein fractions. Therefore, postprandial hyperlipidemia is one possible mechanism contributing to the higher risk of ischemic heart disease in stressed people.

Impact of a false positive blood culture result on the management of febrile children.

OBJECTIVE: To evaluate the impact of a preliminary positive blood culture result, subsequently confirmed to be a false positive blood culture result on rate of hospitalization, antibiotic therapy and use of microbiologic tests. DESIGN: Retrospective chart review. PATIENTS AND METHODS: Children between 1 month and 18 years old on whom a blood culture was performed were eligible, excluding those with an underlying condition for whom a false positive blood culture may be difficult to assess. During the 1-year study period 9959 blood cultures were performed of which 778 (7.8%) produced growth. Charts of 81 patients with a false positive blood culture were reviewed and compared with those of 162 patients with a true negative blood culture. Patients already hospitalized when blood culture was drawn (n = 24) were analyzed separately from those who were not (n = 219). Among these, patients were divided into those who were followed as outpatients (n = 104) and hospitalized (n = 115). RESULTS: Both groups (false positive vs. true negative) were comparable for age, sex, temperature at consultation, white blood cell count and illness severity. Twenty-six percent of patients followed as outpatients who had a false positive blood culture were hospitalized because of a preliminary positive blood culture result. Among patients hospitalized at the initial assessment, the frequency of antibiotic therapy (91% vs. 71%, P < 0.01), the frequency of use of intravenous antibiotics (80% vs. 58%, P < 0.01) and the percentage of unwarranted antibiotic prescription (13% vs. 0%, P < 0.01) were significantly greater in the false positive group than in the true negative group. The same results were found for each of these outcomes among the group of patients followed as outpatients (61% vs. 28%, P < 0.01, 17% vs. 0%, P < 0.01 and 39% vs. 0%, P < 0.01) for false positive vs. true negative, respectively. Patients with false positive blood cultures had more blood cultures drawn subsequently (P < 0.01). Children already hospitalized when the blood culture was obtained did not show significant differences in main outcomes. CONCLUSIONS: False positive blood culture results generate unnecessary hospitalizations, antibiotic therapy and use of microbiologic tests.

Serum lipoprotein profile in Algerian patients with celiac disease.

Celiac disease is characterized by a gluten-induced villous atrophy of the upper small intestine which has an active role in the lipoprotein metabolism. In the present study the lipoprotein profiles of different patients were analyzed to determine the effect of impaired enterocyte function in celiac disease. We compared serum lipid parameters in controls and in celiac disease patients. The major differences between celiac disease patients and the control group were a diminution of cholesterol and phospholipids in HDL and LDL in the former. These differences persisted after treatment; in addition, a lower level of cholesterol in VLDL was observed. Plasma LpAI and apo A-I levels were significantly lower (-17 and -15%) in celiac disease patients than in controls. Both levels remained low after gluten-free diet. In Algerian patients, treatment with gluten-free diet did not give any return towards normal lipids concentrations.

Factors affecting the sterility of work areas in barrier isolators and a biological safety cabinet.

Factors affecting the sterility of the work area in barrier isolators and a biological safety cabinet (BSC) were studied. A study in a mother-and-child tertiary care teaching hospital in Canada examined the effects of a range of variables on the sterility of work areas in four barrier isolators and a standard BSC. The variables consisted of type of equipment (barrier isolator or BSC), day of the week (Monday through Thursday), time of day (0800-1000, 1000-1200, 1200-1400, and 1400-1600), sampling site (16 surfaces and 5 air sedimentation zones), type of product prepared (antimicrobial, total parenteral nutrient solution, etc.), cleaning procedure (before or after primary cleaning), and level of product preparation activity (none to intense). A total of 657 surface and air sedimentation samples, 327 plated onto Trypticase soy agar (TSA) and 330 onto Sabouraud dextrose agar (SAB-D), were taken during a 20-day period. Thirty-three (5%) of the samples yielded microbial growth when cultured (24 on TSA and 9 on SAB-D). A total of 74 isolates were identified, including Bacillus, Staphylococcus, Penicillium, Micrococcus, Corynebacterium, and Mucor species. Single-variable analysis showed that sampling site, sample type, the time of day samples were taken, and the types of equipment contributed significantly to microbial growth in the samples taken. Several variables were associated with microbial growth in samples from the work areas of barrier isolators and a BSC. More study is needed to compare BSCs and barrier isolators with respect to sterility.

Infectious complications of pediatric liver transplantation.

Twenty-five pediatric orthotopic liver transplantations (OLTs) performed in 22 patients at Sainte-Justine Hospital were reviewed for infections complications. One patient died within 12 hours posttransplantation and is excluded. The patients had an average age of 6.1 years (range, 1.25 to 19 years) and an average weight of 20.4 kg (range, 11 to 55 kg). Two patients (9%) were cytomegalovirus (CMV) seropositive and 9 of 19 patients (48%) were Epstein-Barr virus (EBV) seropositive preoperatively. Five of the donors (20%) were CMV seropositive. The most common indications for OLT were biliary atresia (8) and tyrosinemia (7). There were 4 deaths, for an overall mortality rate of 19%. In 3 patients, deaths were related to infection (CMV hepatitis and duodenitis with aortoduodenal fistula, adult respiratory distress syndrome [ARDS] with Streptococcus viridans pneumonia, Escherichia coli cholangitis with progressive hepatic failure). Fifteen patients (72%) had 41 major infections, most of them bacterial, during the first month posttransplantation. These include pneumonia (25%), line sepsis (17%), cholangitis (14%), and tracheitis (14%). There was only one major viral infection, a CMV hepatitis that occurred in the first month posttransplantation. Three patients had fungal infections (8%) associated with hepatic artery thrombosis and recurrent cholangitis. All three patients required retransplantation. There was only one protozoal infection (Pneumocystis carinii pneumonia) causing life-threatening respiratory failure, from which patient recovered without sequelae. Infection still remains a serious complication of OLT. Bacterial infection is common and is usually associated with technical complications. The low rate of CMV infection is related to low incidence of CMV in the donor pool and the minimal use of strong immunosuppressants.

[Stress and social support in relation to psychological distress in community-residing elderly persons in Montreal]. / Importance du stress et du support social comme variables associées à la détresse psychologique dans une population âgée de la région de Montréal.

Our aim was to quantify the degree of association that selected psycho-social and health variables have with psychological distress in the elderly. In order to estimate the level of association, data previously obtained from the "Enquêre Santé Québec" (1987) were entered into a multiple regression analysis with psychological distress as the dependent variable. The independent variables retained were: age, sex, language, physical health, functional health, health status perception, social integration, perceived social support and stress. The scores contained in the data bank were from a representative sample of subjects (n = 361, age = 72.7 +/- 6.3) living in the Montreal area. The results of the regression analysis indicated that psychological distress is significantly related (adjusted R2 = 0.256; p = .000) to the following variables: the interaction "stress events X perceived social support", physical health, functional health and sex. The results of the present study consequently support previous reports relating psychological distress to physical health, social support, stress and sex with a predominant effect on women. Finally, the results give further support to the "buffering effect" of social support on stress.

High prevalence of glycopeptide resistance genes vanB, vanD, and vanG not associated with enterococci in human fecal flora.

The presence of Enterococcus-associated vancomycin resistance genes vanA, vanB, vanD, vanE, and vanG in rectal swabs was investigated in two hospitals using PCR. All vanA genes detected were associated with vancomycin-resistant enterococci (VRE), whereas VRE-associated vanB genes were detected in only one hospital (4.7%). However, in both hospitals, high prevalences of vanB (6.2 and 2.3%), vanD (43.8 and 26.7%), and vanG (10.5 and 6.9%) genes not associated with enterococci were found.

Use of a triplex polymerase chain reaction for the detection and differentiation of Mycoplasma pneumoniae and Mycoplasma genitalium in the presence of human DNA.

PCR primers corresponding to the adhesin genes of Mycoplasma pneumoniae and Mycoplasma genitalium were shown to detect the corresponding organisms specifically. Absence of cross-reaction with seven other mollicute species and six unrelated bacterial species commonly found in humans was demonstrated. Positive control primers directed against human mitochondrial DNA could be mixed with the Mycoplasma primers without loss of specificity or sensitivity. A detection level of 10 c.f.u. of either Mycoplasma species could be readily obtained, even in the presence of 10(4) human cells. The triplex PCR method developed is very simple and does not require hybridization or the use of radioisotopes and allows detection and differentiation of these mycoplasmas against the background of human DNA found in clinical specimens.

Fat ingestion is associated with increased levels of apoC-III- and apoE-B-containing lipoprotein particles in humans.

Apolipoprotein (apo) C-III and apoE have a major influence on post-prandial apoB-containing lipoprotein metabolism. The goal of the present study was to compare the post-prandial changes in particles containing apoB and apoC-III and those containing apoB and apoE. Twenty subjects consumed a fatty meal (1 g of fat kg-1). Human lipoprotein particles were measured by enzyme-linked immunosorbent assay (ELISA) using combinations of anti-apoC-III, -apoE and -apoB. Post-prandial lipaemia was associated with an increase in LpC-III:B (+100%) and LpE:B (+55%; P < 0.05), which occurred 4.07 +/- 1.2 and 4.7 +/- 0.8 h after the meal respectively (P < 0.05). Gel filtration chromatography showed that fasting plasma LpC-III:B and LpE:B eluted in two fractions consisting of large and smaller sized particles; 3 h after the meal, LpC-III:B and LpE:B increased in the very low-density lipoprotein (VLDL) + intermediate-density lipoprotein (IDL) fraction; at 6 h, LpC-III:B and LpE:B decreased in VLDL and LpE:B increased moderately in the low-density lipoprotein (LDL) size range; at 10 h, both concentrations of lipoprotein particles returned to fasting levels. In conclusion, apoC-III-B-containing and apoE-B-containing lipoproteins have different post-prandial metabolic fates. These differences may result in different atherogenic potential.

Expression and detection of pap-, sfa-, and afa-encoded fimbrial adhesin systems among uropathogenic Escherichia coli.

Thirty-five Escherichia coli isolates from young children and women with pyelonephritis, cystitis, or asymptomatic bacteriuria were characterized genotypically and phenotypically. The isolates were examined genotypically by using DNA probes specific for the hemolysis gene and for the pap, sfa, and afa adhesin systems. Genes for the adhesin systems were also detected by polymerase chain reaction, using multigene amplification. The isolates were serotyped, tested for hemolysin production, and classified for their adhesion specificity by hemagglutination and by binding specificity assays. Twenty-seven of the 35 isolates were pap positive. Results showed that pap-positive isolates expressing class I or class II G adhesins were more frequent in cases of pyelonephritis than in cases of cystitis and asymptomatic bacteriuria. Expression of the class III G adhesins was more frequent in isolates from cystitis and asymptomatic bacteriuria than in isolates from pyelonephritis. Multiple adhesin systems and hemolysin were more frequently found in isolates from cases of pyelonephritis than in isolates from cases of cystitis and asymptomatic bacteriuria. There was perfect correlation between the results obtained by polymerase chain reaction and and those obtained by hybridization.

Specificity of the Pseudomonas aeruginosa PAO1 lipoprotein I gene as a DNA probe and PCR target region within the Pseudomonadaceae.

The lipoprotein I gene (oprI) of Pseudomonas aeruginosa PAO1 was cloned and sequenced. A high degree of homology was found between our cloned PAO1 gene sequence and two published oprI sequences. Specific oligonucleotides were designed to amplify the oprI gene by the polymerase chain reaction (PCR). The potential of either the complete gene sequence or the specific oligonucleotide primers as a tool for rapid strain identification was directly assessed against bacterial colonies by PCR or against purified genomic DNA by Southern blot analysis, using a number of representative strains within the Pseudomonadaceae. The oprI gene was found to be well conserved within RNA group I.

Time-resolved identification of modes and measurement of intermodal dispersion in optical fibers.

Picosecond pulses from a tunable mode-locked visible dye laser are injected into a 603-m few-mode optical fiber. Measurements of the output power temporal profile with 35-ps resolution show six clearly resolved modes. Time-profile measurements over a two-dimensional array of points in the fiber output far field yield a picture of each mode that identifies it. Measurements as a function of wavelength and fitting to waveguide dispersion calculations are used to model the fiber core refractive-index profile. As a result for the nominal step-index fiber used in this work, the presence of an index dip at the center of the core was detected.

Unilateral laterothoracic exanthem. A clinicopathologic study of forty-eight patients.

BACKGROUND: Four years ago, we began seeing young children with an unusual, predominantly unilateral, morbilliform and eczematous, self-limited cutaneous eruption. It appeared to correspond to unilateral laterothoracic exanthem (ULE) reported from France and to an eruption described as "a new papular erythema of childhood" in the United States. OBJECTIVE: We conducted a prospective study of ULE to define its clinical evolution, pathology, and therapy. In addition, we performed epidemiologic and microbiologic investigations in an attempt to determine the cause of ULE. METHOD: We studied 48 children with ULE. In some patients, blood, urine, stool, as well as skin biopsy specimens were analyzed. RESULTS: ULE is a morbilliform, eczematous eruption that often begins close to the axilla and spreads to become bilateral, although it usually retains a unilateral predominance. Patients' mean age at onset is 24.3 months, with a female predominance (2:1) and mean duration of 5 weeks, followed by spontaneous resolution that may or may not be improved with topical corticosteroids. It is characterized by a unique eccrine lymphocytic infiltration. Although signs of infection were reported by most patients, no one infectious agent was identified. No significant epidemiologic factor was found. CONCLUSION: ULE, in young children, is a self-limited morbilliform and scarlatiniform eruption that may represent a specific skin reaction to one or more infectious agents.