The effects of feed supplementing Akkemansia muciniphila on incidence, severity, and gut microbiota of necrotic enteritis in chickens.

Akkermansia muciniphila (AM) is a mucin-degrading anaerobe, exerting beneficial effects on gut integrity improvement, inflammatory alleviation, and metabolic regulations in humans. Excess amounts of mucin and mucogenesis in the gut facilitate the development of necrotic enteritis (NE) in chickens. The study aimed to evaluate the effects of oral inoculation of AM on NE prevention and gut modulation in a NE-reproduced model coinfecting with Clostridium perfringens (CP) and Eimeria parasites. A total of 105 commercial 1-day-old broilers were randomly allocated into 5 groups, respectively challenged with Eimeria (Eimeria group), Eimeria and CP (Eimeria+CP group), Eimeria and CP with AM (Eimeria+CP+AM group), Eimeria and AM (Eimeria+AM group), and a placebo (Noninfected group). The treatment of AM exhibited a low degree of amelioration on NE severity. The application neither protected broilers from NE by decreasing NE-positive numbers nor reached a significant reduction in lesion scores in the small intestines. The development of NE reduced species diversity in jejunal microbiota; the pretreatments of AM exacerbated the consequence by losing species richness and promoted the similarity of the jejunal microbial community presented in the Eimeria+CP group. The participation of AM enhanced the increments of genera Clostridium sensu stricto 1 and Escherichia_Shigella and decreased the number of Lactobacillus. The significant variations of genera Clostridium sensu stricto 1 and Lactobacillus in jejunal microbiota were associated with NE development and promotion. In conclusion, oral inoculation of AM promoted the development of NE and modulated the jejunal microbiota favorable for CP overgrowth in broilers. The application of AM as a probiotic in broilers should be cautious on account of the effects to predispose NE.

Bacillus amyloliquefaciens and Saccharomyces cerevisiae feed supplements improve growth performance and gut mucosal architecture with modulations on cecal microbiota in red-feathered native chickens.

OBJECTIVE: The aim of study was to investigate the effects of in-feed supplementation of Bacillus amyloliquefaciens (BA) and Saccharomyces cerevisiae (SC) on growth performance, gut integrity, and microbiota modulations in red-feathered native chickens (RFCs). METHODS: A total of 18,000 RFCs in a commercial farm were evenly assigned into two dietary treatments (control diet; 0.05% BA and 0.05% SC) by randomization and raised for 11 weeks in two separate houses. Fifty RFCs in each group were randomly selected and raised in the original house with the partition for performance evaluations at the age of 9 and 11 weeks. Six non-partitioned RFCs per group were randomly selected for analyses of intestinal architecture and 16S rRNA metagenomics. RESULTS: Feeding BA and SC increased the body weight and body weight gain, significantly at the age of 11 weeks (p<0.05). The villus height/crypt ratio in the small intestines and Firmicutes to Bacteroidetes ratio were also notably increased (p<0.05). The supplementation did not disturb the microbial community structure but promote the featured microbial shifts characterized by the significant increments of Bernesiella, Prevotellaceae_NK3B31_group, and Butyrucimonas, following remarkable decrements of Bacteroides, Rikenellaceae_RC9_gut_group, and Succinatimonas in RFCs with growth benefits. Besides, functional pathways of peptidoglycan biosynthesis, nucleotide excision repair, glycolysis/gluconeogenesis, and aminoacyl transfer ribonucleic acid (tRNA) biosynthesis were significantly promoted (p<0.05). CONCLUSION: In-feed supplementation of BA and SC enhanced the growth performance, improved mucosal architectures in small intestines, and modulated the cecal microbiota and metabolic pathways in RFCs.

Genera and species of the Liothrips lineage (Thysanoptera, Phlaeothripinae) from Taiwan.

This paper lists from Taiwan 11 genera and 28 species of Thysanoptera of the Liothrips lineage. A key is provided to the 11 genera, and Psephenothrips baiheensis sp.n. and P. cymbidas sp.n. are described. A key to the 12 Liothrips species recorded from Taiwan is provided, with two new species, L. dayuilinensis sp.n. and L. hsuae sp.n. One new combination is presented, Liophloeothrips terminaliae (Moulton) comb.n., and Psephenothrips leptoceras Okajima from Japan is newly recorded from Taiwan.

Effects of the monoacylglycerol lipase inhibitor JZL184 on chickens infected with avian pathogenic Escherichia coli O78: A preliminary pharmacokinetic and infection study.

The endocannabinoid (eCB) system modulates the degree of injury caused by inflammation, while enhancing the activity of phagocytes that promote resolution of inflammation and tissue repair. In-vitro studies with the monoacylglycerol lipase (MAGL) inhibitor JZL184 have suggested that increased eCB signaling might enhance the ability of the host immune system to clear invading pathogens. Although the neurochemical effects of JZL184 on the eCB system in rodents are well-known, its immuneregulating effects are less clear, especially in chickens. The primary objective of this study was to explore whether modulating the eCB system affects immune responses in chickens. To do this, we administered JZL184 [10 and 40 mg/kg body weight (BW), intraperitoneal injection] into chickens prior to a challenge with avian pathogenic Escherichia coli (APEC) O78. Bacteria were isolated from livers, blood, air sacs, and hearts at 8, 28, and 56 h post-infection and the gross lesions in air sacs, livers, and hearts were also examined. Serum levels of JZL184 were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), which indicated that the drug was distributed systemically. The number of birds positive for airsacculitis after APEC O78 challenge was marginally higher in groups treated with JZL184 than in the control group (P = 0.064). Rather than augmenting host defense and enhancing pathogen clearance, these results suggested that JZL184 might have immunosuppressive effects that exacerbated APEC O78 infection in chickens.

Le système de l'endocannabinoïde (eCB) module le degré de blessure causé par une inflammation, tout en augmentant l'activité des phagocytes qui favorise la résolution de l'inflammation et la réparation tissulaire. Des études in vitro avec l'inhibiteur de la monoacylglycérol lipase (MAGL) JZL184 suggèrent qu'une augmentation du signal d'eCB pourrait augmenter la capacité du système immunitaire de l'hôte à éliminer les agents pathogènes envahisseurs. Bien que les effets neurochimiques du JZL184 sur le système eCB des rongeurs est bien connu, ses effets immuno-régulateurs sont moins clairs, spécialement chez les poulets. L'objectif primaire de la présente étude était d'explorer si une modulation du système eCB affecte les réponses immunitaires des poulets. Pour se faire, nous avons administré JZL184 [10 et 40 mg/kg de poids corporel (BW), par injection intrapéritonéale] à des poulets avant une infection défi avec l'agent pathogène aviaire Escherichia coli (APEC) O78. Des bactéries furent isolées du foie, du sang, des sacs aériens et du coeur à 8, 28 et 56 h post-infection et les lésions macroscopiques dans les sacs aériens, le foie et le coeur furent également examinées. Les niveaux sériques de JZL184 furent quantifiés par chromatographie liquide couplée à la spectrométrie de masse en tandem (LC-MS/MS), qui indiqua que le médicament était distribué systémiquement. Le nombre d'oiseaux positifs pour aérosacculite après infection par APEC O78 était légèrement plus élevé dans le groupe traité avec JZL184 que dans le groupe témoin (P = 0,064). Plutôt que d'augmenter les mécanismes de défense de l'hôte et d'améliorer l'élimination de l'agent pathogène, ces résultats suggèrent que JZL184 pourrait avoir des effets immunosuppresseurs qui ont exacerbé l'infection par APEC O78 chez les poulets.(Traduit par Docteur Serge Messier).

Proteomic analysis reveals the temperature-dependent presence of extracytoplasmic peptidases in the biofilm exoproteome of Listeria monocytogenes EGD-e.

The foodborne pathogen Listeria monocytogenes resists environmental stresses by forming biofilms. Because this pathogen transmits between the environment and the host, it must adapt to temperature as an environmental stress. In this study, we aimed to identify which proteins were present depending on the temperature in the biofilms of L. monocytogenes EGD-e. Proteins in the supernatants of biofilms formed at 25°C and 37°C were compared using two-dimensional gel electrophoresis and liquid chromatography with tandem mass spectrometry. The larger number of extracytoplasmic proteins associated with cell wall/membrane/envelop biogenesis was identified from the supernatant of biofilms formed at 25°C (7) than those at 37°C (0). Among the 16 extracytoplasmic proteins detected only at 25°C, three were peptidases, namely Spl, Cwh, and Lmo0186. Moreover, mRNA expression of the three peptidases was higher at 25°C than at 37°C. Interestingly, this adaptation of gene expression to temperature was present in sessile cells but not in dispersed cells. After inhibiting the activity of extracytoplasmic peptidases with a protease inhibitor, we noted that the levels of biofilm biomass increased with higher concentrations of the protease inhibitor only when L. monocytogenes grew biofilms at 25°C and not at 37°C. Overall, our data suggest an effect of temperature on the presence of peptidases in L. monocytogenes biofilms. Additionally, increasing the levels of extracytoplasmic peptidases in biofilms is likely a unique feature for sessile L. monocytogenes that causes a naturally occurring breakdown of biofilms and facilitates the pathogen exiting biofilms and disseminating into the environment.

Links between S-adenosylmethionine and Agr-based quorum sensing for biofilm development in Listeria monocytogenes EGD-e.

Listeria monocytogenes is the causative agent of human listeriosis which has high hospitalization and mortality rates for individuals with weakened immune systems. The survival and dissemination of L. monocytogenes in adverse environments can be reinforced by the formation of biofilms. Therefore, this study aimed to understand the mechanisms underlying listerial biofilm development. Given that both nutrient availability and quorum sensing (QS) have been known as the factors influencing biofilm development, we hypothesized that the signal from a sentinel metabolite S-adenosylmethionine (SAM) and Agr-based QS could be synchronous in L. monocytogenes to modulate nutrient availability, the synthesis of extracellular polymeric substances (EPSs), and biofilm formation. We performed biofilm assays and quantitative real-time PCR to investigate how biofilm volumes and the expression of genes for the synthesis of EPS were affected by SAM supplementation, agr deletion, or both. We found that exogenously applied SAM induced biofilm formation and that the expression of genes encoding the EPS synthesis machineries was regulated by SAM and/or Agr QS. Moreover, the gene transcription of components acting in the methyl cycle for SAM synthesis and Agr QS was affected by the signals from the other system. In summary, we reveal an interconnection at the transcriptional level between metabolism and QS in L. monocytogenes and highlight the critical role of metabolite-oriented QS in biofilm development.

The netB-positive Clostridium perfringens in the experimental induction of necrotic enteritis with or without predisposing factors.

The netB-positive Clostridium perfringens has been considered as the requisite to consistently induce necrotic enteritis (NE). However, use of a netB-positive strain did not guarantee consistent NE reproduction unless high protein diets or Eimeria, conceived as 2 major predisposing factors, was incorporated. To establish a refined model, the roles of dietary fishmeal inclusion, Eimeria inoculation, and netB-positive C. perfringens challenge in NE induction and the confounding effects of Eimeria infection on NE were examined. The results showed that the use of netB-positive C. perfringens without a predisposing factor failed to induce NE. Fishmeal incorporation promoted the occurrence of NE but did not significantly affect the incidence of the disease in conjunction with challenge of netB-positive C. perfringens. However, the additional participation of Eimeria infection in the same induction procedure produced significantly higher numbers of NE cases and promoted more severe lesions in chickens (P < 0.05). Inoculation of Eimeria resulted in a significant higher incidence of NE compared to the non-Eimeria treated group (P < 0.05). The results demonstrated that both netB-positive C. perfringens and predisposing factors were required for the reproduction of disease. Mild-to-moderate coccidial infection (coccidial lesion score ≤ 2) was noted in NE cases in this model but severe coccidial infection did not correlate with the occurrence of NE, indicating mild coccidial infection may be beneficial for the development of NE. If multiple species infection of Eimeria precedes the challenge of C. perfringens, days 19 to 21 (1 to 3 D after the last clostridial challenge) was the time period favorable for observations of NE lesions. The time after this period may be subject to bias of severity, incidence, or mortality of NE owing to the profound coccidial lesions in the intestinal region. This study demonstrated that the co-infection with netB-positive C. perfringens and Eimeria species under fishmeal incorporation produced a desirable NE model, being of value in studying the effectiveness of novel feed additives and alternative mitigation strategies to prevent NE.

Analysis of gut microbiota and the effect of lauric acid against necrotic enteritis in Clostridium perfringens and Eimeria side-by-side challenge model.

Gut microbiota has been demonstrated to be involved in intestinal nutrition, defense, and immunity, as well as participating in disease progression. This study was to investigate gut microbiota changes in chickens challenged with netB-positive Clostridium perfringens strain (CP1) and/or the predisposing Eimeria species (Eimeria) and fed diets with fishmeal supplementation. In addition, the effects of lauric acid, a medium-chain fatty acid (MCFA), on necrotic enteritis (NE) reduction and modulation of microbiota were evaluated. The results demonstrated that microbial communities in the jejunum were distinct from those in the cecum, and the microbial community change was more significant in jejunum. Challenge of CP1 in conjunction with Eimeria significantly reduced species diversity in jejunal microbiota, but cecal microbiota remained stable. In the jejunum, CP1 challenge increased the abundance of the genera of Clostridium sensu stricto 1, Escherichia Shigella, and Weissella, but significantly decreased the population of Lactobacillus. Eimeria infection on its own was unable to promote NE, demonstrating decrements of Clostridium sensu stricto 1 and Lactobacillus. Co-infection with CP1 and Eimeria reproduced the majority of NE lesions with significant increment of Clostridium sensu stricto 1 and reduction in Lactobacillus. The advance of changes on these two taxa increased the severity of NE lesions. Further analyses of metagenomeSeq, STAMP, and LEfSe consistently showed significant overgrowth of Clostridium sensu stricto 1 was associated with NE. The supplementation of lauric acid did not reduce NE incidence and severity but decreased the relative abundance of Escherichia Shigella. In conclusion, significant overgrowth of C. perfringens as well as other Clostridium species in Clostridium sensu stricto 1 with the decrement of Lactobacillus in the jejunum is the featured microbiota correlated with NE. Controlling proliferation of Clostridium sensu stricto 1 and manipulation of Lactobacillus in the jejunum should be the strategy to prevent NE.

Characterization of toxin genes and quantitative analysis of netB in necrotic enteritis (NE)-producing and non-NE-producing Clostridium perfringens isolated from chickens.

Necrotic enteritis (NE) in chickens, a Clostridium perfringens infection, has re-emerged due to the removal of antibiotic growth promoters in feeds in recent years, thus contributing to significant economic losses for the industry. Toxins produced by C. perfringens in conjunction with predisposing factors are responsible for the onset and development of NE. Recently, several lines of evidence indicated the potential role of plasmid-encoded toxins in the virulence of NE, particularly necrotic enteritis B-like (NetB) toxin. However, the association of NetB, beta2 toxin (CPB2), and C. perfringens large cytotoxin (TpeL) in clinical NE isolates are not well-established. Therefore, we characterized the toxinotype and the presence of netB, cpb2, and tpeL genes in 15 NE-producing and 15 non-NE-producing C. perfringens isolates using conventional PCR and quantified netB among those isolates by quantitative PCR (qPCR). All isolates were characterized as toxinotype A and were negative for cpe, which is associated with human food poisoning. The netB was detected in 6.7% and 70% of NE-producing isolates by PCR and qPCR, respectively. In 15 non-NE-producing isolates, netB was not detected by conventional PCR, but was detected in 60% of isolates by qPCR. The presence of and the copy number of netB were not significantly different between NE- and non-NE-producing isolates (p >0.05). No difference was observed between NE- and non-NE-producing isolates in the presence of cpb2 or tpeL (p >0.05). These results suggest that the presence of netB, cpb2, and tpeL, as well as the copy number of netB in C. perfringens is not correlated with clinical NE. In addition, we suggest that qPCR, but not conventional PCR, be used to detect netB.

Detection, sequence analysis, and antibody prevalence of porcine deltacoronavirus in Taiwan.

Porcine deltacoronavirus (PDCoV) was initially documented in Hong Kong and later in the United States, South Korea, and Thailand. To investigate if PDCoV is also present in Taiwan, three swine coronaviruses-PDCoV, porcine epidemic diarrhea virus (PEDV), and transmissible gastroenteritis coronavirus (TGEV)-were tested using real-time reverse transcription polymerase chain reaction (rRT-PCR) in 172 rectal swab samples from piglets exhibiting diarrhea between January 2016 and May 2017 on 68 pig farms in Taiwan. The rRT-PCR results were positive for PDCoV (29/172, 16.9%), PEDV (36/172, 20.9%), TGEV (2/172, 1.2%), and coinfections (16/172, 9.3%). After cloning and sequencing, PDCoV nucleocapsid genes were analyzed. Phylogeny results indicated that the nucleotide sequences of all isolates were like those reported in other countries. To further trace PDCoV in the period of 2011 to 2015, an enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against PDCoV. The results showed that 279 of 1,039 (26.9%) sera were positive for the PDCoV nucleocapsid protein, implying that PDCoV might have existed in Taiwan before 2011.

Morphological Change and Decreasing Transfer Rate of Biofilm-Featured Listeria monocytogenes EGDe.

Listeria monocytogenes , a lethal foodborne pathogen, has the ability to resist the hostile food processing environment and thus frequently contaminates ready-to-eat foods during processing. It is commonly accepted that the tendency of L. monocytogenes ' to generate biofilms on various surfaces enhances its resistance to the harshness of the food processing environment. However, the role of biofilm formation in the transferability of L. monocytogenes EGDe remains controversial. We examined the growth of Listeria biofilms on stainless steel surfaces and their effect on the transferability of L. monocytogenes EGDe. The experiments were a factorial 2 × 2 design with at least three biological replicates. Through scanning electron microscopy, a mature biofilm with intensive aggregates of cells was observed on the surface of stainless steel after 3 or 5 days of incubation, depending on the initial level of inoculation. During biofilm development, L. monocytogenes EGDe carried out binary fission vigorously before a mature biofilm was formed and subsequently changed its cellular morphology from rod shaped to sphere shaped. Furthermore, static biofilm, which was formed after 3 days of incubation at 25°C, significantly inhibited the transfer rate of L. monocytogenes EGDe from stainless steel blades to 15 bologna slices. During 7 days of storage at 4°C, however, bacterial growth rate was not significantly impacted by whether bacteria were transferred from biofilm and the initial concentrations of transferred bacteria on the slice. In conclusion, this study is the first to report a distinct change in morphology of L. monocytogenes EGDe at the late stage of biofilm formation. More importantly, once food is contaminated by L. monocytogenes EGDe, contamination proceeds independently of biofilm development and the initial level of contamination when food is stored at 4°C, even if contamination with L. monocytogenes EGDe was initially undetectable before storage.

Incidence and Antimicrobial Susceptibility to Clostridium perfringens in Premarket Broilers in Taiwan.

Clostridium perfringens infection causes subclinical and clinical necrotic enteritis in poultry flocks, and it is estimated to result in US$2 billion of losses worldwide every year. The aims of this study were to determine the incidence, toxin types, and antimicrobial resistance levels to C. perfringens isolated from premarket, 5-wk-old, clinically healthy broiler chickens in Taiwan, and to examine the relationships between intestinal lesions and the numbers of C. perfringens in intestinal contents. In total, 435 samples of chicken ileum contents were collected from 98 broiler farms during June 2012 to February 2013. The C. perfringens isolation rate was 9.9% (43/435). The positive rate of tested farms was 29.6% (29/98). All the isolates were C. perfringens type A, only possessing the cpa gene encoding for toxin α. No netB gene encoding NetB toxin associated with necrotic enteritis, and no cpe gene encoding for the C. perfringens enterotoxin causing human intestinal disorder were detected. A quantitative PCR analysis revealed that the mean C. perfringens number in the intestinal contents was 3.9 × 10(6) colony-forming units (CFU)/g, ranging from 6.85 × 10(2) to 1.61 × 10(7) CFU/g. The gross and histopathologic lesions revealed a positive correlation (p < 0.05) between lesion score and C. perfringens number in the ilea of C. perfringens -positive chickens. Antimicrobial susceptibility tests of all C. perfringens isolates indicated that the minimum inhibitory concentration inhibiting 50% of isolates (MIC50) for amoxicillin, bacitracin, chlortetracycline, enrofloxacin, erythromycin, florfenicol, and lincomycin was ≤0.125, 0.5, 128, 0.25, ≥256, 2, and ≥256 µg/ml, respectively. Most of the C. perfringens isolates were susceptible to amoxicillin, bacitracin, and enrofloxacin but resistant to chlortetracycline, erythromycin, and lincomycin. Interestingly, C. perfringens isolated from chickens with severe lesions had higher MIC50 for erythromycin and lincomycin than those isolates from chickens with mild lesions. Conclusively, reductions in both the incidence of C. perfringens infection on farms and the concentrations of C. perfringens in intestines to improve broiler health are still needed in Taiwan.

Listeria monocytogenes DNA Glycosylase AdlP Affects Flagellar Motility, Biofilm Formation, Virulence, and Stress Responses.

UNLABELLED: The temperature-dependent alteration of flagellar motility gene expression is critical for the foodborne pathogen Listeria monocytogenes to respond to a changing environment. In this study, a genetic determinant, L. monocytogenes f2365_0220 (lmof2365_0220), encoding a putative protein that is structurally similar to the Bacillus cereus alkyl base DNA glycosylase (AlkD), was identified. This determinant was involved in the transcriptional repression of flagellar motility genes and was named adlP (encoding an AlkD-like protein [AdlP]). Deletion of adlP activated the expression of flagellar motility genes at 37°C and disrupted the temperature-dependent inhibition of L. monocytogenes motility. The adlP null strains demonstrated decreased survival in murine macrophage-like RAW264.7 cells and less virulence in mice. Furthermore, the deletion of adlP significantly decreased biofilm formation and impaired the survival of bacteria under several stress conditions, including the presence of a DNA alkylation compound (methyl methanesulfonate), an oxidative agent (H2O2), and aminoglycoside antibiotics. Our findings strongly suggest that adlP may encode a bifunctional protein that transcriptionally represses the expression of flagellar motility genes and influences stress responses through its DNA glycosylase activity. IMPORTANCE: We discovered a novel protein that we named AlkD-like protein (AdlP). This protein affected flagellar motility, biofilm formation, and virulence. Our data suggest that AdlP may be a bifunctional protein that represses flagellar motility genes and influences stress responses through its DNA glycosylase activity.

LMOh7858_0369, a gene encoding a putative leucine-rich repeat-containing protein, is required for virulence of Listeria monocytogenes.

Listeria monocytogenes possesses the highest number of leucine-rich repeat (LRR)-containing proteins among all Gram-positive bacteria; these LRR-containing molecules are known as the 'internalin' family. To understand the functions of largely uncharacterized LRR-containing molecules, we constructed seven deletion mutants in the L. monocytogenes H7858 strain targeting genes in this family and tested their virulence. Among the seven mutants, the ΔLMOh7858_0369 strain and the ΔLMOh7858_2546 strain showed significantly impaired invasiveness of HepG2 cells. We further tested the virulence of these two strains in the intravascular sepsis model using BALB/c mice. Interestingly, the ΔLMOh7858_0369 strain showed significant reduction in organ colonization, bacteremia and invasion of the brain compared with the parental wild-type strain. Host immune responses to listerial intravascular infection were measured at 24 and 72 h post-infection. Transcript levels of several proinflammatory cytokines and chemokines were significantly lower when induced by the ΔlmOh7858_0369 strain than when induced by the wild type. These results suggest that the putative LRR-containing protein encoded by LMOh7858_0369 might be a novel virulence factor of the L. monocytogenes H7858 strain.

The impact of Salmonella Enteritidis on lipid accumulation in chicken hepatocytes.

Salmonella enterica serovar Enteritidis (SE) is a public health concern and infected chickens serve as a reservoir that potentially transmits to humans through food. Although SE seldom causes systemic disease in chickens, virulent SE strains can colonize in intestines and lead a persistent infection of the liver. The liver is the primary organ for lipid metabolism in chickens and the site for production and assembly of main components in yolk. We performed a time-course experiment using LMH-2A cells that were infected with SE and co-incubated with ß-oestradiol to evaluate if SE infection affected lipid metabolism and subsequently changed lipoprotein formation for egg yolk. The results indicated that lipid accumulation significantly increased in infected LMH-2A cells while the viability of these cells was only slightly decreased. The mRNA expressions of lipid transportation and most lipogenetic genes including sterol regulatory element binding protein 1, acetyl-CoA carboxylase, fatty-acid synthase, long-chain-fatty-acid-CoA ligase 1, peroxisome proliferator-activated receptor-γ, and very-low-density lipoproteins (VLDLs) II were significantly up-regulated while the expression of lipogenetic-related stearoyl-CoA denaturase 1 was down-regulated. Moreover, decline in lipid transportation of hepatocytes was evidenced by the down-regulation of oestrogen receptor α which promotes VLDLy formation, an increase of intra-cellular accumulation of Apoprotein B (ApoB) protein, and a decrease of cellular excretion of VLDL protein. Conclusively, SE infection could elevate lipid synthesis and reduce lipid transportation in the chicken hepatocytes. These changes may lead excessive lipid accumulation in liver and slower lipoprotein deposition in yolk.

Listeriolysin O mediates cytotoxicity against human brain microvascular endothelial cells.

Penetration of the brain microvascular endothelial layer is one of the routes Listeria monocytogenes use to breach the blood-brain barrier. Because host factors in the blood severely limit direct invasion of human brain microvascular endothelial cells (HBMECs) by L. monocytogenes, alternative mechanisms might be used by this bacterium to penetrate the endothelial cell layer. In this study, we evaluated the cytotoxicity of proteins secreted by L. monocytogenes against HBEMCs using a live/dead staining method. Interestingly, the integrity of the plasma membrane of HBMECs was impaired by proteins secreted by the EGD wild-type strain but not proteins secreted by the isogenic ΔprfA strain. Therefore, we investigated the cytotoxicity of proteins secreted by several isogenic mutant strains (ΔplcA, Δmpl and Δhly) incapable of producing the prfA-regulated bacterial products PlcA, Mpl and LLO, respectively. Results from both fluorescent microscopy and flow cytometry analyses showed that proteins secreted by the Δhly strain were not cytotoxic to HBMECs, whereas those secreted by the ΔplcA and Δmpl strains were cytotoxic. These results suggest that LLO-mediated cytotoxicity against brain microvascular endothelial cells enables L. monocytogenes to effectively penetrate the brain microvascular endothelial layer.

[The use of systematic review to develop a self-management program for CKD].

BACKGROUND: Chronic kidney disease (CKD) has become a public health issue of international concern due to its high prevalence. The concept of self-management has been comprehensively applied in education programs that address chronic diseases. In recent years, many studies have used self-management programs in CKD interventions and have investigated the pre- and post-intervention physiological and psychological effectiveness of this approach. However, a complete clinical application program in the self-management model has yet to be developed for use in clinical renal care settings. PURPOSE: A systematic review is used to develop a self-management program for CKD. METHOD: Three implementation steps were used in this study. These steps include: (1) A systematic literature search and review using databases including CEPS (Chinese Electronic Periodical Services) of Airiti, National Digital Library of Theses and Dissertations in Taiwan, CINAHL, Pubmed, Medline, Cochrane Library, and Joanna Briggs Institute. A total of 22 studies were identified as valid and submitted to rigorous analysis. Of these, 4 were systematic literature reviews, 10 were randomized experimental studies, and 8 were non-randomized experimental studies. (2) Empirical evidence then was used to draft relevant guidelines on clinical application. (3) Finally, expert panels tested the validity of the draft to ensure the final version was valid for application in practice. RESULTS: This study designed a self-management program for CKD based on the findings of empirical studies. The content of this program included: design principles, categories, elements, and the intervention measures used in the self-management program. This program and then was assessed using the content validity index (CVI) and a four-point Liker's scale. The content validity score was .98. The guideline of self-management program to CKD was thus developed. CONCLUSIONS / IMPLICATIONS FOR PRACTICE: This study developed a self-management program applicable to local care of CKD. It is hoped that the guidelines developed in this study offer a reference for clinical caregivers to improve their healthcare practices.

Characterization of a potential Listeria monocytogenes virulence factor associated with attachment to fresh produce.

A study to determine the attachment of L. monocytogenes serotype 4b strain F2365 on vegetables and fruits was conducted. In an initial study, we screened 32 genes encoding surface proteins and lipases of the strain to find highly expressed genes on lettuce leaves. The results showed that transcription levels of LMOf2365_0413, LMOf2365_0498, LMOf2365_0859, LMOf2365_2052, and LMOf2365_2812 were significantly upregulated on lettuce leaves. In silico analysis showed that LMOf2365_0859 contains a putative cellulose binding domain. Thus, we hypothesized that this gene may be involved in an attachment to vegetables, and named it lcp (gene encoding Listeria cellulose binding protein [LCP]). lcp mutant (Δlcp) and lcp complement (F2365::pMAD::cat::lcp) strains were generated by homologous recombination. The abilities of a wild-type (WT) strain, the Δlcp strain, and the complemented strain to attach to lettuce leaves were evaluated, which indicated that the attachment of the Δlcp strain to lettuce was significantly less than that of the WT and the complemented strains. Similar results were observed for baby spinach and cantaloupe. Fluorescence microscopy and field emission scanning microscopy analysis further supported these findings. The binding of L. monocytogenes to cellulose was determined using cellulose acetate-coated plates. The results showed that a binding ability of the Δlcp strain was significantly lower than that of the wild type. Combined, these results strongly suggest that LCP plays an important role in an attachment to vegetables and fruits.

Global gene expression of Listeria monocytogenes to salt stress.

Outbreaks of listeriosis caused by the ingestion of Listeria-contaminated ready-to-eat foods have been reported worldwide. Many ready-to-eat foods, such as deli meat products, contain high amounts of salt, which can disrupt the maintenance of osmotic balance within bacterial cells. To understand how Listeria monocytogenes adapts to salt stress, we examined the growth and global gene expression profiles of L. monocytogenes strain F2365 under salt stress using oligonucleotide probe-based DNA array and quantitative real-time PCR (qRT-PCR) analyses. The growth of L. monocytogenes in brain heart infusion (BHI) medium with various concentrations of NaCl (2.5, 5, and 10%) was significantly inhibited (P < 0.01) when compared with growth in BHI with no NaCl supplementation. Microarray data indicated that growth in BHI medium with 1.2% NaCl upregulated 4 genes and down-regulated 24 genes in L. monocytogenes, which was confirmed by qRT-PCR. The transcript levels of genes involved in the uptake of glycine betaine/(L)-proline were increased, whereas genes associated with a putative phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS), metabolic enzymes, and virulence factor were down-regulated. Specifically, the expression levels of PTS transport genes were shown to be dependent on NaCl concentration. To further examine whether the down-regulation of PTS genes is related to decreased cell growth, the transcript levels of genes encoding components of enzyme II, involved in the uptake of various sugars used as the primary carbon source in bacteria, were also measured using qRT-PCR. Our results suggest that the decreased transcript levels of PTS genes may be caused by salt stress or reduced cell growth through salt stress. Here, we report global transcriptional profiles of L. monocytogenes in response to salt stress, contributing to an improved understanding of osmotolerance in this bacterium.

Transcriptome analysis of Listeria monocytogenes grown on a ready-to-eat meat matrix.

The contamination of ready-to-eat (RTE) meat products with Listeria monocytogenes is a major concern for the food industry. For a better understanding of the adaptation and survival ability of L. monocytogenes grown on turkey deli meat, the transcriptome of L. monocytogenes strain F2365 was determined with a microarray. Microarray data were validated with a quantitative real-time reverse transcription PCR assay. Based on the microarray data, 39 and 45 genes from L. monocytogenes were transcriptionally upregulated and down-regulated, respectively. The genes regulated at the transcriptional level were mainly involved in energy metabolism, fatty acid and phospholipid metabolism, biosynthesis of proteins, transport and binding proteins, DNA metabolism, cellular processes, and regulatory functions. No significant change was noted for the expression of genes encoding known virulence factors such as sigB, prfA, inlA, inlB, plcA, plcB, and hly. These results suggest that L. monocytogenes grown on RTE deli meat changes its transcription of proteins involved in its metabolic pathways to obtain an energy source or to adapt to environmental change without increasing the expression of virulence factors. The global transcriptome profiles provide a better understanding of the growth or adaptation of L. monocytogenes in RTE meat products.