Genetic variants of Kudoa septempunctata (Myxozoa: Multivalvulida), a flounder parasite causing foodborne disease.

Foodborne disease outbreaks caused by raw olive flounders (Paralichthys olivaceus) parasitized with Kudoa septempunctata have been reported in Japan. Origins of olive flounders consumed in Japan vary, being either domestic or imported, and aquaculture-raised or natural. Although it is unknown whether different sources are associated with different outcomes, it is desirable to identify whether this is the case by determining whether unique K. septempunctata strains occur and if so, whether some are associated with foodborne illness. We here developed an intraspecific genotyping method, using the sequence variation of mitochondrial genes. We collected olive flounder samples from foodborne disease outbreaks, domestic fish farms or quarantine offices and investigated whether K. septempunctata genotype is associated with pathogenicity or geographic origin. The 104 samples were classified into three genotypes, ST1, ST2 and ST3. Frequency of symptomatic cases differed by genotypes, but the association was not statistically significant. Whereas K. septempunctata detected from aquaculture-raised and natural fish from Japan were either ST1 or ST2, those from fish inspected at quarantine from Korea to Japan were ST3. Our method can be applied to phylogeographic analysis of K. septempunctata and contribute to containing the foodborne disease. The genotype database is hosted in the PubMLST website (http://pubmlst.org/kseptempunctata/).

Toxicokinetics and absolute oral bioavailability of melamine in broiler chickens.

The objective of this study was to investigate the toxicokinetic characteristics of melamine in broilers due to the limited information available for livestock. Melamine was then administered to broiler chickens at an intravenous (i.v.) or oral (p.o.) dosage of 5.5 mg/kg of body weight, and plasma samples were collected up to 48 h. The concentration of melamine in each plasma sample was analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Melamine was measurable up to 24 h after i.v. and p.o. administration. A one-compartment model was developed to describe the toxicokinetics of melamine in broilers. Following i.v. administration, the values for the elimination half-life (t(1/2ß)), the volume of distribution (Vd ), and the clearance (CL) were 4.42 ± 1.02 h, 00.52 ± 0.18 L/kg, and 0.08 ± 0.01 L/h/kg, respectively. The absolute oral bioavailability (F) was 95.63 ± 3.54%. The results suggest that most of the administered melamine is favorably absorbed from the alimentary tract and rapidly cleared by the kidneys in broiler chickens.

Utility of the phylotoxigenic relationships among trichothecene-producing Fusarium species for predicting their mycotoxin-producing potential.

Species of the genus Fusarium are well-known plant pathogens and mycotoxigenic fusaria are associated with health hazards to humans and animals. There is a need to understand the mechanisms of mycotoxin production by Fusarium species and to predict which produce mycotoxins. In this study, the Fusarium phylogenetic tree was first inferred among trichothecene producers and related species. We reconstructed the maximum likelihood (ML) tree based on the combined data from nucleotide sequences of rDNA cluster regions, the ß-tubulin gene (ß-tub) and the elongation factor 1α gene (EF-1α). Second, based on this tree topology, the ancestral states of the producing potential of type A and B trichothecenes (TriA and TriB), zearalenone (ZEN), moniliformin (MON), beauvericin (BEA) and enniatins (ENN) were reconstructed using the maximum parsimony (MP) method based on the observed production by extant species as reported in the literature. Finally, the species having the potential to produce each of these six mycotoxins was predicted on the basis of the parsimonious analysis. The ML tree indicated that the Fusarium species analysed in this study could be divided into two major clades. Clade I was divided into four distinct subclades: I-a, I-b, I-c and I-d. Furthermore, the parsimony reconstruction suggested that the potential for producing MON and ZEN was gained or lost only once, and that the producing potential for TriA and TriB, BEA and ENN was repeatedly gained and lost during the evolutionary history of the Fusarium species analysed in this study. Interestingly, the results showed the possibility that several species, about which reports were scarce with regard to mycotoxin production, have the potential to produce one or more of the six evaluated in this study. The phylogenetic information therefore helps one to predict the mycotoxin-producing potential by Fusarium species, and these "phylotoxigenic relationships" may be useful for predicting the pathogenicity of fungi.

Prevalence of the main food-borne pathogens in retail food under the national food surveillance system in Japan.

The National Food Surveillance System in Japan was formed in 1998 to monitor the contamination of retail foods with bacterial pathogens. Approximately 2000-3000 samples were tested annually, and the data from food categories that had more than 400 samples collected during 1998-2008 were analysed. With regard to meat, the frequency of positive samples for Salmonella in chicken for raw consumption and ground chicken was 12.7% and 33.5%, respectively. Moreover, Shiga toxin-producing Escherichia coli (STEC) O157 was found in ground meat, organ meat and processed meat, although at a low frequency (0.1%). The prevalence of Campylobacter jejuni/coli was 13.3% and 20.9% in chicken for raw consumption and ground chicken, respectively. In vegetables and fruit, Salmonella was detected in cucumber, lettuce, sprout and tomato samples at a frequency of around 0.1-0.2%. With regard to seafood, Salmonella was found in 0.5% of oysters for raw consumption. Seafood was not contaminated with STEC O157 or Shigella. Serotype Infantis was the most frequently detected serotype of Salmonella in seafood, followed by the serotypes Typhimurium, Schwarzengrund and Manhattan. In ground chicken, 72.2% of the strains were identified as the serotype Infantis. E. coli, as an indicator of food hygiene, was detected in all food categories. The results show the prevalence of the above-mentioned pathogens in the retail food supplied in Japan; further, they indicate that consumption of raw food carries the risk of contracting food-borne infections.

Exposure and risk assessment for ochratoxin A and fumonisins in Japan.

The authors performed exposure and risk assessments based on surveillance studies of retail foods in Japan that were undertaken during the past six years (2004-2010). The exposure to ochratoxin A (OTA) and fumonisins (FBs) in different age groups, including toddlers and young children (1-6 years old), older children (7-14 years old), adolescents (15-19 years old) and adults (over 20 years old) was simulated, and the risk of these mycotoxins was evaluated by comparing the provisional maximum tolerated daily intake (PMTDI) for FBs and the provisional maximum tolerated weekly intake (PMTWI) for OTA established by the FAO/WHO Joint Export Committee on Food Additives. The exposure assessment for both mycotoxins in each age group in Japan indicated that the highest exposure occurred in toddlers and children, but in all cases the percentage of the PMTWI and PMTDI at the 99th percentile of exposure was less than 35% for OTA and 10% for FBs.

Dietary intake of aflatoxins in the adult Malaysian population - an assessment of risk.

Exposure to aflatoxins in the adult Malaysian diet was estimated by analysing aflatoxins in 236 food composites prepared as "ready for consumption". Dietary exposure to aflatoxin B1 (AFB1) ranged from 24.3 to 34.00 ng/kg b.w./day (lower to upper bound), with peanuts being the main contributor. Estimated liver cancer risk from this exposure was 0.61-0.85 cancers/100,000 population/year, contributing 12.4%-17.3% of the liver cancer cases. Excluding AFB1 occurrence data higher than 15 µg/kg reduced exposure by 65%-91% to 2.27-11.99 ng/kg b.w./day, reducing the cancer risk to 0.06-0.30 cancers/100,000 population/year (contributing 1.2%-6.1% liver cancer cases). Reducing further the ML of AFB1 from 15 to 5 µg/kg yielded 3%-7% greater drop in the exposure to 0.47-10.26 ng/kg b.w./day with an estimated risk of 0.01-0.26 cancers/100,000 population/year (0.2%-5.1% liver cancer cases attributed to dietary AFB1). These findings indicate that current MLs are adequate in protecting Malaysians' health.

Simulation of deoxynivalenol intake from wheat consumption in Japan using the Monte Carlo method.

The aim of this study was to evaluate the current advisory level in Japan for deoxynivalenol (DON) in foods. To this end, we estimated the intake of DON based on its presence in wheat using a probabilistic computer simulation method. Values for the concentration of DON in wheat were based on those reported in surveys of 638 wheat samples conducted from 2002 to 2004. Data regarding consumption of 108 wheat-based products according to age group were obtained from the 2002 Japan national survey on food consumption. Two data sets on the consumption of wheat-based products and contamination of DON in wheat were analysed using three DON regulatory scenarios: no regulation, 1100 µg kg(-1) and 2000 µg kg(-1). Because consumption distributions contained two peaks for each age category, it was assumed that two log-normal distributions for each age category were needed to achieve a better fit to the distribution models. The results of simulated DON intake using the Monte Carlo method showed that children aged 1-6 years have the highest DON intake. However, the 95th percentile of simulated intake of DON in each age group was below the provisional maximum tolerable daily intake (TDI) of 1 µg kg(-1) body weight using any regulation scenario. The 99th percentile of simulated DON intake in the 1-6-year-old group was greater than TDI at approximately 2 µg kg(-1) body weight. These results suggest that the current dietary intake of DON from wheat consumption does not exert a significant health effect, but we may need to reconsider the current regulation value for the 1-6-year-old age group. In addition, we may need a better method to fit the distribution to the log-normal distribution better.

Rapid and effective DNA extraction method with bead grinding for a large amount of fungal DNA.

To identify a rapid method for extracting a large amount of DNA from fungi associated with food hygiene, extraction methods were compared using fungal pellets formed rapidly in liquid media. Combinations of physical and chemical methods or commercial kits were evaluated with 3 species of yeast, 10 species of ascomycetous molds, and 4 species of zygomycetous molds. Bead grinding was the physical method, followed by chemical methods involving sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium bromide (CTAB), and benzyl chloride and two commercial kits. Quantity was calculated by UV absorbance at 260 nm, quality was determined by the ratio of UV absorbance at 260 and 280 nm, and gene amplifications and electrophoresis profiles of whole genomes were analyzed. Bead grinding with the SDS method was the most effective for DNA extraction for yeasts and ascomycetous molds, and bead grinding with the CTAB method was most effective with zygomycetous molds. For both groups of molds, bead grinding with the CTAB method was the best approach for DNA extraction. Because this combination also is relatively effective for yeasts, it can be used to extract a large amount of DNA from a wide range of fungi. The DNA extraction methods are useful for developing gene indexes to identify fungi with molecular techniques, such as DNA fingerprinting.

Exposure to aflatoxins in Japan: risk assessment for aflatoxin B1.

The intake of total aflatoxins (AFT) and aflatoxin B(1) (AFB(1)) from food in Japan was estimated from AFT and AFB(1) concentration and frequency data in 24 foods (884 samples) from a 3-year retail market survey from the summer of 2004 to the winter of 2006, and by food consumption data from the National Health and Nutrition Survey performed in 2005. The AFT and AFB(1) survey revealed that peanut, peanut products, cocoa, chocolate, pistachio, white pepper, red pepper, almond, job's tears, buckwheat and corn grits are considered to be contributors of AFT (or AFB(1)) intake in Japan (maximum AFB(1) (AFT) levels ranged from 0.21 to 28.0 microg kg(-1) (from 0.21 to 9.0 microg kg(-1))) in AFT-contaminated food. A probabilistic approach using the Monte Carlo method was carried out to simulate an estimate of the AFT (or AFB(1)) intake distributions in each age group in Japan. In this study, AFB(1) intake ranged from 0.003 to 0.004 ng kg(-1) body weight day(-1) (from lower to upper limits), and the potential risk for cancer using a formula devised by the Joint Food and Agricultural Organization/World Health Organization (FAO/WHO) Expert Committee on Food Additives (JECFA) was estimated at 0.00004-0.00005 person/year/100,000 persons, even though this was in the higher levels (95.0th percentile) of the consumer population. The results suggest that the current dietary intake of AFB(1) in Japan has no appreciable effect on health.

Muscle tissue kinetics of oxytetracycline following intramuscular and oral administration at two dosages to giant freshwater shrimp (Macrobrachium rosenbergii).

The giant river shrimp (Macrobrachium rosenbergii), a native species of Thailand, is either exported for commercial purposes or supplied to meet the local requirements in Thailand. Limited pharmacokinetic information of the major antibiotic, oxytetracycline (OTC), is available for this freshwater shrimp. The purpose of the present study was to investigate the muscle tissue kinetics of OTC in M. rosenbergii following either intramuscular (i.m.) or oral (p.o.) administration at two dosages of 11 and 22 mg/kg body weight (b.w.). The concentration of OTC in shrimp tissues was measured using high-performance liquid chromatography (HPLC) equipped with a fluorescence detector. Muscle tissue concentrations were below the detection limit (LOD, 0.1 microg/g) after 96 and 120 h, following i.m. and p.o. administration, respectively. Peak muscle concentrations (C(max)) were 3.47 and 1.73 microg/g after i.m. and p.o. administration at a single dose of 11 mg/kg b.w. whereas they were 6.03 and 2.51 microg/g at a single dose of 22 mg/kg b.w., respectively. A noncompartment model was developed to describe the pharmacokinetics of OTC in the giant freshwater shrimp. The terminal half-lives of OTC were 28.68 and 28.09 h after i.m. and p.o. administration at a single dose of 11 mg/kg b.w., but 29.95 and 27.03 h at a single dose of 22 mg/kg b.w., respectively. The relative bioavailability was 82.32 and 64.67% following i.m. and p.o. administration, respectively. Based on the pharmacokinetic data, i.m. and p.o. administration with OTC at a dose of 11 mg/kg b.w. would be appropriate for use in giant freshwater shrimp farming. To avoid the OTC residue in shrimp muscle, it should take at least seven half-lives (8 days) to wash out the drug from the muscle of M. rosenbergii.

Nivalenol and the targeting of the female reproductive system as well as haematopoietic and immune systems in rats after 90-day exposure through the diet.

Nivalenol (NIV) is considered to be an important trichothecene mycotoxin produced by Fusarium species because of its frequent contamination in wheat and barley worldwide. The present study examined the subchronic toxicity of NIV in male and female F344 rats fed diets containing 0, 6.25, 25 and 100 mg kg(-1) of the toxin for 90 days. During the experimental period there was a decrease in the white blood cell count at 100 mg kg(-1) in males and at > or =6.25 mg kg(-1) in females. Histopathologically, treatment-related changes were observed in the haematopoietic and immune systems in both sexes and in the female reproductive system at 100 mg kg(-1). Flow cytometric analysis of splenic cells revealed an elevation in the ratio of helper/cytotoxic T-lymphocytes at 100 mg kg(-1). In summary, NIV targets the female reproductive system as well as haematopoietic and immune systems in rats fed NIV for 90 days. Based on a significant decrease in white blood cells in female rats relative to controls, the lowest observable effect level was calculated as 0.4 mg kg(-1) body weight day(-1).

Fate of fusarenon-X in broilers and ducks.

In order to investigate the comparative fates and dispositions of fusarenon-X (FX) in broilers and ducks, FX was administered i.v. or orally (p.o.) to broilers and ducks. The FX and its metabolite (nivalenol, NIV) were determined in plasma and excreta using gas chromatography-mass spectrometry. The plasma concentrations of FX were determined up to 180 and 120 min in broilers and ducks, respectively, after i.v. and p.o. administration. The NIV was eliminated more slowly than its parent compound. The FX disposition fit an open 2-compartment pharmacokinetic model in broilers and ducks. The elimination half-life (t(1/2beta)) of FX was longer in ducks than in broilers. The elimination rate constant (kel) was higher in broilers than in ducks, whereas the oral bioavailability of FX was higher in ducks than in broilers. The gas chromatography-mass spectrometry profile in plasma showed that a large proportion of FX was recovered as NIV after administration of FX in both broilers and ducks. In vitro incubation of liver microsomal and cytosolic fractions with FX demonstrated that the liver and kidney are capable of the FX-to-NIV conversion. Thus, this study demonstrated that FX is absorbed more efficiently in ducks than in broilers, whereas it is eliminated more slowly in ducks than in broiler chickens. Consequently, the toxicity would have more serious consequences in ducks rather than broilers.

Aflatoxin and ochratoxin A contamination of retail foods and intake of these mycotoxins in Japan.

A survey was undertaken of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2), ochratoxin A (OTA), and fumonisin B1 (FB1), B2 (FB2) and B3 (FB3) contamination of various retail foods in Japan during 2004-05. The mycotoxins were analysed by high-performance liquid chromatography (HPLC), liquid chromatography/mass spectrometry (LC/MS) or high-performance thin-layer chromatography (HPTLC). Aflatoxins (AFs) were detected in ten of 21 peanut butter and in 22 of 44 bitter chocolate samples; the highest level of AFB1, 2.59 microg kg(-1), was found in peanut butter. Aflatoxin contamination was not observed in corn products (n = 55), corn (n = 110), peanuts (n = 120), buckwheat flour (n = 23), dried buckwheat noodles (n = 59), rice (n = 83) or sesame oil (n = 20). OTA was detected in 120 out of 192 samples of oatmeal, wheat flour, rye, buckwheat flour, raw coffee, roasted coffee, raisin, beer, wine and bitter chocolate, but not in rice or corn products. OTA levels in the positive samples were below 13 microg kg(-1). AFs and OTA intakes through the consumption of foods containing cacao were estimated using the data for mycotoxin contamination in bitter chocolate and those for the consumption of foods containing cacao in Japan.

Production and characterization of a monoclonal antibody that cross-reacts with the mycotoxins nivalenol and 4-deoxynivalenol.

Nivalenol is a mycotoxin produced by certain fungi that are pathogenic to important cereal crops, in particular maize, wheat, and barley. This toxin, 3alpha,4beta,7alpha,15-tetrahydroxy-12,13-epoxytrichothec-9-en-8-one, is found worldwide and is closely related to 4-deoxynivalenol (DON or vomitoxin), a mycotoxin associated with outbreaks of Fusarium head blight in North America. The literature on the toxicity of nivalenol suggests it is similar, if not more toxic, than DON. Despite the development of rapid immunologically based assays for detecting DON, such assays have not existed for detecting nivalenol without chemical modification of the analyte. This paper describes the development of a monoclonal antibody using a nivalenol-glycine protein conjugate. The monoclonal antibody was most specific for an acetylated form of DON (3-Ac-DON), but it exhibited sensitivity and cross-reactivity that were useful for detecting nivalenol and DON at relevant levels without the need to modify either toxin chemically. In an competitive indirect ELISA format, the concentrations of toxins able to inhibit colour development by 50% (IC50) were 1.7, 15.8, 27.5, 68.9, and 1740 ng ml(-1) for the mycotoxins 3-Ac-DON, DON, nivalenol, 15-Ac-DON, and fusarenon-X, respectively. The antibody was also used to develop a competitive direct ELISA for DON and nivalenol, with IC50's of 16.5 ng ml(-1) (DON) and 33.4 ng ml(-1) (nivalenol). These assays are capable of detecting both DON and nivalenol simultaneously, a property that may be useful in regions where these toxins co-occur or in formats, such as immunoaffinity columns, where co-isolation of both toxins is desirable.

Migration of formaldehyde and acetaldehyde into mineral water in polyethylene terephthalate (PET) bottles.

The levels of formaldehyde (FA) and acetaldehyde (AA) in polyethylene terephthalate (PET) bottles and in commercial mineral water are reported. All the water samples bottled in Japan contained detectable levels of FA (10.1-27.9 microg l(-1)) and AA (44.3-107.8 microg l(-1)). Of 11 European bottled water samples, eight did not contain either FA or AA, while the remaining three had detectable levels of FA (7.4-13.7 microg l(-1)) and AA (35.9-46.9 microg l(-1)). In three North American bottled water samples, two contained FA (13.6 and 19.5 microg l(-1)) and AA (41.4 and 44.8 microg l(-1)), and one did not. Regardless of the region of origin, all the sterilized water samples contained FA and AA, whilst in contrast, none of the unsterilized water without carbonate contained FA or AA. Of the carbonated water samples, three contained FA and AA, and one did not. When fortified with FA and AA, the commercial water sample without otherwise detectable FA and AA was able to reduce levels, although the commercial water sample containing FA and AA could not. The presence of bacteria in the commercial water samples was investigated using an ATP-based bioluminescent assay and heterotrophic plate count method. The commercial water without FA and AA contained heterotrophic bacteria, whilst the commercial water with FA and AA did not contain detectable bacteria. It is suggested that in this case both FA and AA migrated from PET materials, but were subsequently decomposed by the heterotrophic bacteria in the unsterilized water.

Antibacterial activity of plants used in cooking for aroma and taste.

Thirty-three plants used in cooking for aroma and taste were examined for antibacterial activity against pathogens causing foodborne infections. Vibrio parahaemolyticus and Staphylococcus aureus were sensitive to many kinds of plant extracts, whereas Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Enteritidis populations decreased in only six, one, and three plant extracts, respectively. The polyphenol content in the plants was significantly different between the antibacterial plants and nonantibacterial plants, indicating that the polyphenols were related to the antibacterial action of these plants. Antibacterial activity of various concentrations of leaf extracts from Japanese persimmon, white cedar, and grape were investigated. Japanese persimmon and white cedar leaf extracts at low concentrations affected L. monocytogenes and V. parahaemolyticus rapidly. With grape leaf extract at low concentrations, the population of L. monocytogenes decreased similarly to Japanese persimmon and white cedar leaves. This study demonstrates that many plants used in cooking for aroma and taste contain polyphenols and exhibit antibacterial activity against foodborne pathogens.

Experimental murine hyalohyphomycosis with soil-derived isolates of Fusarium solani.

Two strains of soil-borne Fusarium solani, both characterized for their ability to produce cyclosporin A and C, were examined for their pathogenicity in severe combined immunodeficiency (SCID) and BALB/c male mice. Intravenous (i.v.) infections with F. solani conidia were performed. No mortality was observed after infection with 0.3-1.6 x 10(7) cfu per mouse in SCID and BALB/c mice. When mice were infected with 0.8-1.5 x 10(6) cfu per mouse and 2 days later with 1.2-1.9 x 10(6) cfu per mouse, 28.6-85.7% survival occurred over a 25-day period, depending on the F. solani strain and the inbred mouse line used. Death was preceded by renal insufficiency affecting both kidneys. Furthermore, i.v. injection with heat-killed conidia followed 2 days later by injecting viable conidia resulted in renal infection in both breeds of mice. F. solani isolated from infected organs was more virulent than the original isolate, and 3/8 (37.5%) of BALB/c and 4/7 (57.1%) of SCID mice died after receiving a single dose. Dissemination to the brain was found only in SCID mice, but torticollis was observed in both mouse breeds. Soil-borne F. solani isolates possess poor pathogenic potential for mice, but either two successive infective doses or a primary injection with heat-killed conidia followed by a single infective dose breaks through host defenses in normal and immunoincompetent mice. Mouse passage increased the pathogenicity of two soil-derived F. solani strains.

Wine has activity against entero-pathogenic bacteria in vitro but not in vivo.

We studied the activity of wine against entero-pathogenic bacteria both in vitro and in vivo. The food-borne bacteria were killed in both red and white wine within 30 min. However, the results of a Salmonella infection experiment using mice suggested that wine was not effective in preventing food-borne diseases in vivo.

Differential upregulation of TNF-alpha, IL-6, and IL-8 production by deoxynivalenol (vomitoxin) and other 8-ketotrichothecenes in a human macrophage model.

The effects of deoxynivalenol (DON or vomitoxin) and four closely related 8-ketotrichothecenes on proinflammatory cytokine and chemokine production were evaluated in a clonal human macrophage model. U-937 cells, which represent a human monocytelike histocytic lymphoma, were differentiated into macrophages by preincubation with phorbol 12-myristate 13-acetate (PMA). Differentiated macrophages were incubated with DON in the absence or presence of lipopolysaccharide (LPS), and supernatant was analyzed by enzyme-linked immunosorbent assay (ELISA) for the proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), and for the chemokine interleukin-8 (IL-8). In the absence of LPS, DON at 500 or 1,000 ng/ml upregulated TNF-alpha production as early as 3 h and up to 6 h, whereas 100 to 1,000 ng/ml of DON significantly increased production of IL-6 from 3 to 24 h and IL-8 from 6 to 48 h. In cells costimulated with 0.2 microg/ml LPS, DON at 500 or 1000 ng/ml markedly superinduced TNF-alpha and IL-8 production. Although 100 ng/ml of DON also potentiated LPS-induced IL-6 production, 500 or 1,000 ng/ ml of the toxin suppressed the LPS-induced IL-6 response. Four other 8-ketotrichothecenes, fusarenon X, nivalenol, 3-acetyl DON, and 15-acetyl DON, were also capable of upregulating or suppressing TNF-alpha, IL-6, and IL-8 production at concentrations similar to that of DON. In total, the results suggest that DON and other 8-ketotrichothecenes have the potential to both directly induce and superinduce proinflammatory cytokine and chemokine expression in human macrophages, even at toxin concentrations that are cytotoxic.

Blockade of Salmonella enteritidis passage across the basolateral barriers of human intestinal epithelial cells by specific antibody.

Antibodies specific to Salmonella enteritidis (S.E.) were obtained from immunized egg yolk, and their protective effects against S.E. were studied by using monolayer-cultured human intestinal epithelial cells, Caco-2 and T84. The Salmonella adherence and entry to the cells were partially inhibited by the antibodies. The antibodies inhibited the decrease in transepithelial electrical resistance (TEER) of the intestinal epithelial monolayers and IL-8 secretion of the cells induced by S.E. invasion. Also, the antibodies blocked the penetration of bacteria through the cell layer although they did not inhibit the growth of bacteria in the cells. Confocal microscopic photographs revealed the bacteria in the infected monolayer cells were bound to antibodies. These results indicate that anti-S.E. antibodies may protect the cells from destruction induced by S.E. invasion in intestinal epithelial cells in addition to the partial inhibition of adhesion and invasion of S.E. at the cell surface. Passive antibodies against invasive bacteria would be useful to prevent the migration of S.E. to blood not only at the cell surface but also inside of intestinal epithelial cells.