Lactococcus piscium: a psychrotrophic lactic acid bacterium with bioprotective or spoilage activity in food-a review.

The genus Lactococcus comprises 12 species, some known for decades and others more recently described. Lactococcus piscium, isolated in 1990 from rainbow trout, is a psychrotrophic lactic acid bacterium, probably disregarded because most of the strains are unable to grow at 30°C. During the last 10 years, this species has been isolated from a large variety of food: meat, seafood and vegetables, mostly packed under vacuum (VP) or modified atmosphere (MAP) and stored at chilled temperature. Recently, culture-independent techniques used for characterization of microbial ecosystems have highlighted the importance of Lc. piscium in food. Its role in food spoilage varies according to the strain and the food matrix. However, most studies have indicated that Lc. piscium spoils meat, whereas it does not degrade the sensory properties of seafood. Lactococcus piscium strains have a large antimicrobial spectrum, including Gram-positive and negative bacteria. In various seafoods, some strains have a protective effect against spoilage and can extend the sensory shelf-life of the products. They can also inhibit the growth of Listeria monocytogenes, by a cell-to-cell contact-dependent. This article reviews the physiological and genomic characteristics of Lc. piscium and discusses its spoilage or protective activities in food.

Development and characterization of microsatellite markers for the oomyceta Aphanomyces euteiches.

Aphanomyces euteiches Drechsler is a serious pathogen of leguminous crops that causes devastating root rot of pea worldwide. Given that A. euteiches is a diploid organism, robust, codominant markers are needed for population genetics studies. We have developed and screened a microsatellite-enriched small-insert genomic library for identification of A. euteiches SSR containing sequences. Fourteen out of the 48 primer pairs designed to amplify SSR, produced unambiguous polymorphic products in our test population of 94 isolates. The number of alleles at each locus ranged from one to four. The identification of new markers would enhance the ability to evaluate the genetic structure of A. euteiches populations, and pathogen evolution.

Identification of lactic acid bacteria involved in the spoilage of pasteurized "foie gras" products.

The spoiling microflora of a re-packaged French "foie gras" product was studied. A total of 54 isolates, originating from two different factories, were identified using phenotypical and molecular methods (partial 16S rDNA sequencing). Weissella viridescens was the main species detected in the products from factory 1 (64% of the isolates). These products had a low lactic acid concentration and were considered as non-spoiled. The microflora of factory 2 was dominated mainly by the genus Lactobacillus (95% of the isolates), and the high lactic acid concentration of these products was linked with a strong spoilage. Among the 30 Lactobacillus strains, three species were predominant: Lactobacillus sakei (nine isolates), Lactobacillus coryniformis (eight isolates) and Lactobacillus paraplantarum (five isolates). Challenge tests were performed to confirm the involvement of the Lactobacillus strains in the spoilage of the product. Sterile "foie gras" samples were inoculated with 14 LAB strains from the collection. The most acidifying strains belonged to the species L. sakei, Lactobacillus plantarum and L. paraplantarum. This confirmed the role of the strains from the Lactobacillus genus as the main spoilers of "foie gras" products and will be useful to design new quality protocols and extend the shelf-life of these products.

Inhibition of Brochothrix thermosphacta and sensory improvement of tropical peeled cooked shrimp by Lactococcus piscium CNCM I-4031.

AIMS: To investigate the antimicrobial spectrum of Lactococcus piscium CNCM I-4031 and its protective effect in cooked and peeled shrimp against Brochothrix thermosphacta. METHODS AND RESULTS: Sixteen pathogenic and spoiling bacteria were inhibited in Elliker, but not in shrimp juice agar plates. In shrimp packed under modified atmosphere and stored at 8 degrees C, B. thermosphacta (10(3) CFU g(-1)) was inhibited by 4.1 log CFU g(-1) when co-inoculated with L. piscium (10(6) CFU g(-1)). Brochothrix thermosphacta spoiled the product after 11 days, with the emission of strong butter/caramel off-odours. In co-culture with L. piscium, sensory shelf-life was extended by at least 10 days. The inhibition was partially explained by a drop in pH from 6.6 to 5.6. The physicochemical composition of shrimp and shrimp juice was established to identify the inhibition mechanisms involved. CONCLUSION: Lactococcus piscium CNCM I-4031 has a wide antimicrobial spectrum. The strain inhibits B. thermosphacta in shrimp and significantly prolongs sensory shelf-life. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactococcus piscium CNCM I-4031 is shown to be a promising agent for improving shrimp quality and may be tested against pathogens and in other food matrices. Knowledge of the physicochemical composition of shrimp and shrimp juice will allow the development of a chemically defined model medium for determining the inhibition mechanisms involved.

Selection and evaluation of seafood-borne psychrotrophic lactic acid bacteria as inhibitors of pathogenic and spoilage bacteria.

In this study, inhibitory psychrotrophic lactic acid bacteria were isolated and investigated for future use in biopreservation of seafood products. Screening of 5575 colonies isolated from various seafood products resulted in the selection of 132 colonies presenting inhibitory properties. Among them, 52 isolates had characteristics of LAB and showed growth at 15 degrees C but not at 30 degrees C. The inhibition spectrum of these 52 isolates against 14 target strains (Gram-positive and -negative) showed inhibition of typical seafood spoiling and pathogenic bacteria and enabled the formation of seven interesting clusters. Sequencing of the 16S rRNA gene of a representative isolate from each cluster identified three Leuconostoc gelidum, two Lactococcus piscium, one Lactobacillus fuchuensis and one Carnobacterium alterfunditum. Theses strains did not produce histamine nor tyramine, and showed no particular antibiotic resistance profile. Growth rate as a function of temperature was tested for one L. piscium and one L. gelidum isolate and confirmed their psychrotrophic behavior. One out of seven isolates showed bacteriocin-like activity. The inhibition mechanisms of the other isolates are still unknown but may be due to competition for substrate. Absence of a bacteriocin-like component could be a positive point to gain rapid authorization for food application in France. This collection of LAB is now ready for testing on products.

Divercin V41 from gene characterization to food applications: 1998-2008, a decade of solved and unsolved questions.

The emergence of an increasing number of antibiotic resistant human clinical bacteria has been a great cause of concern for the last decades. As an example, Staphylococcus aureus isolates in the hospital environment are becoming more and more resistant to antibiotics including vancomycin which is considered as a last line of defence in treatment of Staphylococcus aureus-resistant methicillin. On the other hand, food safety is threatened by development of pathogenic bacteria including Listeria monocytogenes, Campylobacter jejuni, Salmonella enteritidis, Escherichia coli O157:H7 and Staphylococcus aureus. The use of antimicrobial peptides such as glycopeptides, semi-synthetic peptides, bacteriocins including lantibiotics offers a hope to face these clinical and food microbiology concerns. Clinical approval of new chemotherapeutic agents requires a long period of time. Research on bacteriocins has demonstrated potential use to fight against undesired foodborne pathogens but the use industrial use of bacteriocins is limited. To date only lantibiotic nisin and in class IIa bacteriocin Pediocin PA-1 are legally used as food preservative in many countries. The present minireview is focused on divercin V41 (DvnV41), a class IIa bacteriocin naturally produced by Carnobacterium divergens V41. The last decade has been the witness of intensive investigations carried out on this cationic peptide tempting to answer multiple questions covering basic and applied aspects. DvnV41 has shown a wide spectrum of activity either alone or in combination with nisin and/or polymixins (synergistic effect). This outcome indicates that Cb. divergens V41 could potentially be used for safe and efficient prevention of L. monocytogenes growth in cold smoked salmon.

Study of the bacterial ecosystem in tropical cooked and peeled shrimps using a polyphasic approach.

The characterization of the microbial ecosystem of cooked tropical shrimps was carried out using a polyphasic approach. First, culture-dependent methods were used for bacterial enumeration and the phenotypic and molecular identification of bacterial isolates. Then, culture-independent methods, including PCR-TTGE (V3 region of the 16S rRNA gene), provided a fingerprinting of bacterial DNA directly extracted from shrimps. Two batches of cooked and peeled tropical shrimps were stored at 5 and 15 degrees C for 5 and 3 weeks, respectively. Trained panelists carried out a sensory evaluation and microbiological enumerations were performed. When spoilage of samples was perceived, several colonies were isolated from the total viable count media. Thus, 137 bacterial strains were identified by phenotypic and molecular tests. Lactic acid bacteria (LAB) constituted the major group with the most represented genera being Carnobacterium (C. divergens, C. maltaromaticum and indiscernible C. alterfunditum/pleistocenium), Vagococcus (indiscernible V. carniphilus/fluvialis) and Enterococcus (E. faecalis and E. faecium). The other groups corresponded to Brochothrix thermosphacta and Enterobacteriaceae (Serratia liquefaciens). In PCR-TTGE profiles some of DNA fragments were assigned to those of standard strains (S. liquefaciens, B. thermosphacta, E. faecalis, C. divergens and C. maltaromaticum) or identified isolates from culture-dependent analysis (E. faecium). Other additional informations were provided by fragment cloning (Psychrobacter sp, Citrobacter gillenii and Firmicute). In conclusion, TTGE is an excellent tool to monitor the evolution of the microbial ecosystem in seafood products.

Response of Listeria monocytogenes to liquid smoke.

AIMS: To investigate the effect of liquid smoke on growth, survival, proteomic pattern and haemolytic potential of Listeria monocytogenes. METHODS AND RESULTS: Growth and survival curves were recorded in brain-heart infusion broth supplemented with three concentrations of liquid smoke. L. monocytogenes growth was inhibited in the presence of 15 microg ml(-1) phenol while a rapid decrease in cell viability occurred in the presence of 30 microg ml(-1) phenol. The proteome of L. monocytogenes cytosoluble proteins was slightly modified after 2-h incubation with 30 microg ml(-1) phenol but no protein already characterized in response to other known stresses was induced, except the protease ClpP. Liquid smoke inhibited the haemolytic potential without affecting hly gene expression, showing a potential inhibition of protein activity or stability. CONCLUSIONS: The presence of liquid smoke in a rich medium strongly affected growth and survival of L. monocytogenes. Brief smoke stress affected the metabolic pathways and inhibited the haemolytic activity of L. monocytogenes. SIGNIFICANCE AND IMPACT OF STUDY: This study is a first step in the investigation of the influence of a smoked product on L. monocytogenes strains.

Inactivation of Salmonella Typhimurium and Listeria monocytogenes using high-pressure treatments: destruction or sublethal stress?

AIMS: To investigate potential resuscitation of Listeria monocytogenes and Salmonella Typhimurium after high hydrostatic pressure treatments. METHODS AND RESULTS: Pressure treatments were applied at room temperature for 10 min on bacterial suspensions in buffers at pH 7 and 5.6. Total bacterial inactivation (8 log(10) CFU ml(-1) of bacterial reduction) obtained by conventional plating was achieved regarding both micro-organisms. Treatments at 400 MPa in pH 5.6 and 600 MPa in pH 7 for L. monocytogenes and at 350 MPa in pH 5.6 and 400 MPa in pH 7 for S. Typhimurium were required respectively. A 'direct viable count' method detected some viable cells in the apparently totally inactivated population. Resuscitation was observed for the two micro-organisms during storage (at 4 and 20 degrees C) after almost all treatments. In the S. Typhimurium population, 600 MPa, 10 min, was considered as the treatment achieving total destruction because no resuscitation was observed under these storage conditions. CONCLUSIONS: We suggest a delay before performing counts in treated samples in order to avoid the under-evaluation of surviving cells. SIGNIFICANCE AND IMPACT OF THE STUDY: The resuscitation of pathogen bacteria after physical treatments like high hydrostatic pressure has to be considered from the food safety point of view. Further studies should be performed in food products to study this resuscitation phenomenon.

A validated liquid chromatography-mass spectrometry method for the determination of leukotrienes B4 and B5 produced by stimulated human polymorphonuclear leukocytes.

A validated high-performance liquid chromatography (HPLC)-mass spectrometry method has been developed for the simultaneous assay of leukotrienes (LTs) B4 and B5, derived from omega-6 arachidonic acid and omega-3 polyunsaturated fatty acids (PUFA), respectively, produced by human polymorphonuclear leukocytes (PMNLs) stimulated with calcium ionophore A23187. The HPLC separation of PMNL ether extracts was performed on a reversed-phase column using a gradient elution program of 15 mM ammonium acetate and MeOH. Detection was performed by electrospray ionization-single quadripole mass spectrometry using single ion reaction monitoring in the negative mode at m/z 333.3 [M-H](-) and m/z 335.2 for prostaglandin B2/LTB5 and LTB4, respectively. The calibration curves for LTB4 and LTB5 were linear over the ranges 165-990 and 0.825-13.2 ng/ml, respectively. The lower limit of quantification for LTB5 was 0.66 ng/ml. The mean absolute recoveries for LTB4 and LTB5 were 81+/-4.8% and 82+/-5.9%, respectively. The method is precise with mean interday CVs for LTB4 and LTB5 within 7.1-10.7, and 3.8-9.4%, respectively, and accurate (range of interday deviations for LTB4 and LTB5 were -7.8 to 1, and -5 to 9% , respectively). The method has been validated and is being applied to the simultaneous quantification of the leukotrienes B4 and B5 in stimulated PMNLs in a clinical protocol studying the influence of a diet enriched in omega-3 PUFA on various surrogate markers of inflammation in young cystic fibrosis patients.

Biodiversity of Listeria monocytogenes sensitivity to bacteriocin-producing Carnobacterium strains and application in sterile cold-smoked salmon.

AIMS: The aim of this study was to demonstrate the inhibitory capacity of Carnobacterium strains against a collection of Listeria monocytogenes strains in cold-smoked salmon (CSS). METHODS AND RESULTS: Three bacteriocin-producing strains, Carnobacterium divergens V41, C. piscicola V1 and C. piscicola SF668, were screened for their antilisterial activity against a collection of 57 L. monocytogenes strains selected from the French smoked salmon industry, using an agar spot test. All the Listeria strains were inhibited but three different groups could be distinguished differing in sensitivity to the three Carnobacterium strains. However, C. divergens V41 always had the highest inhibitory effect. The antilisterial capacity was then tested in sterile CSS blocks co-inoculated with Carnobacterium spp. and mixtures of L. monocytogenes strains. C. divergens V41 was the most efficient strain, maintaining the level of L. monocytogenes at <50 CFU g(-1) during the 4 weeks of vacuum storage at 4 and 8 degrees C, whatever the sensitivity of the set of L. monocytogenes strains. CONCLUSIONS: C. divergens V41 may be a good candidate for biopreservation in CSS. SIGNIFICANCE AND IMPACT OF THE STUDY: A biopreservation strategy for CSS against the risk of L. monocytogenes was investigated using bacteriocin-producing lactic acid bacteria.

Evidence on inhibition of Listeria monocytogenes by divercin V41 action.

AIMS: The aim of this study was to investigate the role of divercin V41 in inhibition and prevention of Listeria monocytogenes. METHODS AND RESULTS: Carnobacterium divergens V41 deficient in bacteriocin production was isolated and characterized by enzyme-liked immunosorbent assay, multiplex polymerase chain reaction and bacteriocin diffusion test. Carnobacterium divergens V41 (divercin+) and Carnobacterium divergens V41C9 (divercin-) were grown in the presence of L. monocytogenes in smoked salmon model medium. Carnobacterium divergens V41, but not C. divergens V41C9, was able to inhibit growth of L. monocytogenes. The results indicate that inhibition of L. monocytogenes in the presence of C. divergens V41 is because of the production of divercin V41 and not to a nutritional advantage. CONCLUSIONS: Carnobacterium divergens V41 may be a promising agent in food safety. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrates a potential use of a bacteriocin producing lactic acid bacteria in the area food protection.

Physiological damages of Listeria monocytogenes treated by high hydrostatic pressure.

High hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. This study investigated the damages inflicted on Listeria monocytogenes cells treated by high pressure for 10 min at 400 MPa in pH 5.6 citrate buffer. Under these conditions, no cell growth occurred after 48 h on plate count agar. Scanning electron microscopy (SEM) revealed that cellular morphology was not really affected. Measuring propidium iodide (PI) staining followed by flow cytometry demonstrated that membrane integrity was damaged in a small part of the population, although the membrane potential evaluated by oxonol fluorescence or measured by analytical methods was reduced from - 86 to - 5 mV. These results for the first time showed that such combined methods as fluorescent dyes monitored by flow cytometry and physiological activity measurements provide valuable indications on cellular viability.

Morphological and physiological characterization of Listeria monocytogenes subjected to high hydrostatic pressure.

High hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. That inactivation is usually assessed by the number of colonies growing on solid media after treatment. Under normal conditions the method does not permit recovery of damaged cells and may underestimate the number of cells that will remain viable and grow after a few days in high-pressure-processed foodstuffs. This study investigated the damage inflicted on Listeria monocytogenes cells treated by high pressure for 10 min at 400 MPa in pH 5.6 citrate buffer. Under these conditions, no cell growth occurred after 48 h on plate count agar. Scanning electron microscopy, light scattering by flow cytometry, and cell volume measurements were compared to evaluate the morphological changes in cells after pressurization. All these methods revealed that cellular morphology was not really affected. Esterase activity, as assessed either by enzymatic activity assays or by carboxy fluorescein diacetate fluorescence monitored by flow cytometry, was dramatically lowered, but not totally obliterated, under the effects of treatment. The measurement of propidium iodide uptake followed by flow cytometry demonstrated that membrane integrity was preserved in a small part of the population, although the membrane potential measured by analytical methods or evaluated by oxonol uptake was reduced from -86 to -5 mV. These results showed that such combined methods as fluorescent dyes monitored by flow cytometry and physiological activity measurements provide valuable indications of cellular viability.

Continuous infusion of ceftazidime with a portable pump is as effective as thrice-a-day bolus in cystic fibrosis children.

UNLABELLED: Continuous infusion (CI) of beta-lactam antibiotics provides a stable concentration which may result in a better activity against gram-negative bacteria if exceeding the minimum inhibitory concentration (MIC). Treatment outcome after 24 h CI of ceftazidime (CAZ) in cystic fibrosis (CF) children was compared with the bolus administration regimen. Fourteen CF children with chronic Pseudomonas aeruginosa pulmonary infection were treated during 14 days with the conventional CAZ thrice-a-day bolus infusion (regimen A), and few months later with 24 h Cl of CAZ (regimen B) using a portable pump. Amikacin was added to both regimens. Clinical efficacy of treatment was assessed using pulmonary, inflammatory and nutritional variables. Bacteriological analyses and CAZ concentrations in serum and sputum were also measured. All patients improved clinically with both regimens. Among the parameters used to compare both regimens, only prealbumin values improved (regimen A: + 0.08 g/l versus regimen B: +0.11 g/l P = 0.015). No clinically significant side-effects were noted. In regimen A, the mean predose (trough level) CAZ concentration in serum was highly variable (range 2.2-45.4 gg/ml) with some values (32% of samples) below the MIC of P. aeruginosa isolates found in the sputum of the patients. In regimen B, the serum CAZ level achieved was 28.5+/-8.4 microg/ml without any value below the MIC. The mean sputum levels were comparable in both regimens. No CAZ resistant strains of P. aerugino.sa appeared between and directly after the treatments. CONCLUSION: The clinical outcome of children with cystic fibrosis treated with 24 h continuous infusion of ceftazidime was no different from that achieved with the conventional bolus infusion regimen. Continuous infusion provided a sustained serum ceftazidime level well above the P. aeruginosa minimum inhibitory concentration. Continuous infusion was well tolerated and appreciated by the children and this may promote home therapy for cystic fibrosis children.

Enumeration of Carnobacterium divergens V41, Carnobacterium piscicola V1 and Lactobacillus brevis LB62 by in situ hybridization-flow cytometry.

The specific detection and enumeration of Lactobacillus brevis LB62, Carnobacterium divergens V14 and Carnobacterium piscicola VI were studied by in situ hybridization-flow cytometry. The method was performed on the exponential growth phase with three probes targeting 16S rRNA labelled with fluorescein isothicyanate (FITC): EUB338 probe universal for Eubacteria, Lb probe specific for Lact. brevis and Cb probe specific for the genus Carnobacterium. EUB338 was used to determine the permeabilization and hybridization conditions for the cells. The Lb probe gave no hybridization signal whereas the Cb probe allowed the detection and quantification by flow cytometry at 520 nm of the two Carnobacterium strains in pure culture or in mixtures with Listeria innocua F.

Effects of intravenously infused fish oil on platelet fatty acid phospholipid composition and on platelet function in postoperative trauma.

BACKGROUND: The aim of this study was to assess the short-term effect of IV infusion of fish oil emulsion on the fatty acid profiles of platelet phosphatidylcholine and phosphatidylethanolamine and on platelet function in postoperative patients. METHODS: Over a 7-day period, 10 patients received a 20% soybean fat emulsion with an added 10% marine fish oil emulsion, whereas 9 controls received only 20% soybean fat emulsion. RESULTS: By comparison with controls, in patients receiving fish oil, (1) a large increase in eicosapentaenoic acid (20:5n-3) was observed in both platelet phosphatidylcholine (1.55% +/- 0.17% vs 0.38% +/- 0.06% by weight, p < .01) and phosphatidylethanolamine 2.21% +/- 0.18% vs 0.66% +/- 0.08% by weight, p < .01); (2) eicosapentaenoic acid (20:5n-3)/arachidonic acid (20:4n-6) ratios doubled in both platelet phosphatidylcholine (p < .01) and phosphatidylethanolamine (p < .05); (3) with collagen as aggregating factor, maximal reaction speed decreased (p < .02) and latency increased (p < .002); and (4) no toxic effect, in particular no increase of postoperative bleeding and no perturbation of hepatic and renal function, was observed during the fish oil infusion. CONCLUSIONS: A short-term IV infusion of fish oil clearly modifies the platelet composition and changes some parameters of platelet function.

Essential fatty acid deficiency in well nourished young cystic fibrosis patients.

UNLABELLED: Essential fatty acid deficiency is well known in cystic fibrosis patients, but its pathogenesis remains unclear. It might be related to protein-energy malnutrition which is a common feature of cystic fibrosis or to some specific defects in fatty acid metabolism. To avoid the deleterious effects of protein-energy malnutrition, this study assesses the plasma phospholipid fatty acid pattern in well nourished young cystic fibrosis subjects. Sixteen cystic fibrosis subjects aged 6.6-20.0 years were studied and compared to 16 healthy controls matched for gender, age and nutritional status. Plasma phospholipids were separated by thin layer chromatography and phospholipid fatty acid pattern was determined by gas liquid chromatography. Anthropometry and dual-energy X-ray absorptiometry showed that lean body mass, fat-free mass and fat mass were similar in the two groups. Nutritional inquiry showed higher ingestion of macronutrients by cystic fibrosis subjects than by controls. Plasma phospholipid palmitoleic acid and eicosatrienoic acid were higher, and by contrast linoleic acid and docosahexaenoic acid were lower in cystic fibrosis subjects than in controls. The ratio linoleic acid/arachidonic acid was lower and the ratio eicosatrienoic acid/arachidonic acid was higher in cystic fibrosis subjects than in controls. CONCLUSION: Essential fatty acid deficiency is present in young cystic fibrosis subjects in the absence of protein-energy malnutrition. It means that this deficiency is probably related to specific defects in fatty acid metabolism.

Bone mineral content in cystic fibrosis patients: correlation with fat-free mass.

OBJECTIVE: To assess the bone mineral content in well nourished patients with cystic fibrosis and to seek a correlation with fat-free mass. METHODS: Fourteen cystic fibrosis patients aged 6 to 20 years were studied and compared to 14 healthy controls matched for gender, age, and nutritional status. Bone mineral content was determined by dual energy x ray absorptiometry (DEXA). RESULTS: Nutritional inquiry showed higher ingestion of macronutrients and micronutrients by cystic fibrosis patients than by controls. Mean whole skeleton bone mineral content was 1.184 (SD 0.536) kg in cystic fibrosis patients and 1.229 (0.576) kg in controls (p = 0.84). Mean lumbar spine bone mineral content was 0.031 (0.013) kg and 0.031 (0.016) kg, respectively (p = 0.99). Anthropometry, bioelectrical impedance analysis, and DEXA showed that fat-free mass was similar in the two groups. Bone mineral content was strongly correlated to fat-free mass. Mean blood calcium, phosphorus, serum 25-hydroxyvitamin D (25-OHD), parathyroid hormone (PTH), and osteocalcin were similar in both groups. CONCLUSIONS: Bone mineral content and body composition are normal in a well nourished young cystic fibrosis population. Osteopenia previously reported in cystic fibrosis patients probably has nutritional origins and is therefore not related to a primary defect in bone mineral metabolism.

Effects of intravenously infused egg phospholipids on lipid and lipoprotein metabolism in postoperative trauma.

Lipid emulsions contain not only triglyceride (TG)-rich particles but also phospholipid (PL)-rich particles that are believed to trap free cholesterol and apoprotein E, when they are infused in excess. The present study was designed to evaluate the effects of such abnormal PL-rich particles on lipid metabolism during a 5-day infusion in man. Eighteen patients undergoing esophagectomy were evenly randomized to receive intravenously during 5 days 1.75 g.kg-1.d-1 long-chain TG from either a 10% lipid emulsion with a PL/TG weight ratio of 0.12 (group A), a 10% emulsion with a PL/TG weight ratio of 0.06 (group B), or a 20% emulsion with a PL/TG weight ratio of 0.06 (group C). Plasma PL, free cholesterol, and apoprotein E increased progressively in group A (4.1 +/- 0.3 mmol/L, 2.4 +/- 0.3 mmol/L, and 0.089 +/- 0.012 g/L on day 5, respectively) but not in groups B (2.7 +/- 0.3 mmol/L, 1.3 +/- 0.2 mmol/L, and 0.048 +/- 0.007 g/L) and C (2.4 +/- 0.2 mmol/L, 1.2 +/- 0.1 mmol/L, and 0.050 +/- 0.006 g/L). Free fatty acids and TGs remained constant and similar in each group postoperatively. After fat infusion had been stopped at the end of the fifth day, the elimination of plasma TGs over the next 4 hours was comparable in the three groups. We conclude that excess egg PLs induce alterations of plasma lipids even within a few days.