Association Between Inflammatory Bowel Diseases and Celiac Disease: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: There is controversy over the association between celiac disease (CeD) and inflammatory bowel diseases (IBD). We performed a systematic review and meta-analysis to assess evidence for an association between CeD and IBD. METHODS: We searched databases including MEDLINE, EMBASE, CENTRAL, Web of Science, CINAHL, DARE, and SIGLE through June 25, 2019 for studies assessing the risk of CeD in patients with IBD, and IBD in patients with CeD, compared with controls of any type. We used the Newcastle-Ottawa Scale to evaluate the risk of bias and GRADE to assess the certainty of the evidence. RESULTS: We identified 9791 studies and included 65 studies in our analysis. Moderate certainty evidence found an increased risk of CeD in patients with IBD vs controls (risk ratio [RR] 3.96; 95% confidence interval [CI] 2.23-7.02) and increased risk of IBD in patients with CeD vs controls (RR 9.88; 95% CI 4.03-24.21). There was low-certainty evidence for the risk of anti-Saccharomyces antibodies, a serologic marker of IBD, in patients with CeD vs controls (RR 6.22; 95% CI 2.44-15.84). There was low-certainty evidence for no difference in risk of HLA-DQ2 or DQ8 in patients with IBD vs controls (RR 1.04; 95% CI 0.42-2.56), and very low-certainty evidence for an increased risk of anti-tissue transglutaminase in patients with IBD vs controls (RR 1.52; 95% CI 0.52-4.40). Patients with IBD had a slight decrease in risk of anti-endomysial antibodies vs controls (RR 0.70; 95% CI 0.18-2.74), but these results are uncertain. CONCLUSIONS: In a systematic review and meta-analysis, we found an increased risk of IBD in patients with CeD and increased risk of CeD in patients with IBD, compared with other patient populations. High-quality prospective cohort studies are needed to assess the risk of CeD-specific and IBD-specific biomarkers in patients with IBD and CeD.

Treatment with Saccharomyces boulardii reduces the inflammation and dysfunction of the gastrointestinal tract in 5-fluorouracil-induced intestinal mucositis in mice.

Intestinal mucositis is an important toxic side effect of 5-fluorouracil (5-FU) treatment. Saccharomyces boulardii is known to protect from intestinal injury via an effect on the gastrointestinal microbiota. The objective of the present study was to evaluate the effect of S. boulardii on intestinal mucositis induced by 5-FU in a murine model. Mice were divided into saline, saline (control)+5-FU or 5-FU+S. boulardii (16 × 109 colony-forming units/kg) treatment groups, and the jejunum and ileum were removed after killing of mice for the evaluation of histopathology, myeloperoxidase (MPO) activity, and non-protein sulfhydryl group (mainly reduced glutathione; GSH), nitrite and cytokine concentrations. To determine gastric emptying, phenol red was administered orally, mice were killed 20 min after administration, and the absorbance of samples collected from the mice was measured by spectrophotometry. Intestinal permeability was measured by the urinary excretion rate of lactulose and mannitol following oral administration. S. boulardii significantly reversed the histopathological changes in intestinal mucositis induced by 5-FU and reduced the inflammatory parameters: neutrophil infiltration (control 1·73 (SEM 0·37) ultrastructural MPO (UMPO)/mg, 5-FU 7·37 (SEM 1·77) UMPO/mg and 5-FU+S. boulardii 4·15 (SEM 0·73) UMPO/mg); nitrite concentration (control 37·00 (SEM 2·39) µm, 5-FU 59·04 (SEM 11·41) µm and 5-FU+S. boulardii 37·90 (SEM 5·78) µm); GSH concentration (control 477·60 (SEM 25·25) µg/mg, 5-FU 270·90 (SEM 38·50) µg/mg and 5-FU+S. boulardii 514·00 (SEM 38·64) µg/mg). Treatment with S. Boulardii significantly reduced the concentrations of TNF-α and IL-1ß by 48·92 and 32·21 % in the jejunum and 38·92 and 61·79 % in the ileum. In addition, S. boulardii decreased the concentrations of chemokine (C-X-C motif) ligand 1 by 5-fold in the jejunum and 3-fold in the ileum. Interestingly, S. boulardii reduced the delay in gastric emptying (control 25·21 (SEM 2·55) %, 5-FU 54·91 (SEM 3·43) % and 5-FU+S. boulardii 31·38 (SEM 2·80) %) and induced the recovery of intestinal permeability (lactulose:mannitol ratio: control 0·52 (SEM 0·03), 5-FU 1·38 (SEM 0·24) and 5-FU+S. boulardii 0·62 (SEM 0·03)). In conclusion, S. boulardii reduces the inflammation and dysfunction of the gastrointestinal tract in intestinal mucositis induced by 5-FU.

Saccharomyces as a vaccine against systemic candidiasis.

We have shown heat-killed Saccharomyces (HKY) is a protective vaccine against aspergillosis and coccidioidomycosis. To test the hypothesis that the efficacy of HKY- induced protection may be due to the cross-reactive antigens in the cell walls of the different fungi, we studied the effect of HKY against systemic candidiasis. Male CD-1 mice were given different regimens of HKY subcutaneously prior to intravenous challenge with Candida albicans. Compared to PBS controls, the administration of HKY (6 × 10(7)) 3, 4 or 6 times prolonged survival (all P < 0.05) and reduced fungal load in the kidney (all P < 0.05). An HKY dose of 1.2 × 10(8) given 4 times prolonged survival (P = 0.02), but showed dose-limiting toxicity. HKY given by an oral route, or by a subcutaneous route with alum as an adjuvant, did not improve survival. Overall, we found that HKY protects mice from infection by Candida albicans in a dose-and regimen-dependent manner. To understand the protection induced by HKY against different fungal species, additional studies of epitope mapping are warranted.

Anti-inflammatory effects of Saccharomyces boulardii mediated by myeloid dendritic cells from patients with Crohn's disease and ulcerative colitis.

Saccharomyces boulardii (Sb) is a probiotic yeast that has demonstrated efficacy in pilot studies in patients with inflammatory bowel disease (IBD). Microbial antigen handling by dendritic cells (DC) is believed to be of critical importance for immunity and tolerance in IBD. The aim was to characterize the effects of Sb on DC from IBD patients. Highly purified (>95%), lipopolysaccharide-stimulated CD1c(+)CD11c(+)CD123(-) myeloid DC (mDC) from patients with ulcerative colitis (UC; n = 36), Crohn's disease (CD; n = 26), or infectious controls (IC; n = 4) were cultured in the presence or absence of fungal supernatant from Sb (SbS). Phenotype and cytokine production and/or secretion of IBD mDC were measured by flow cytometry and cytometric bead arrays, respectively. T cell phenotype and proliferation were assessed in a mixed lymphocyte reaction (MLR) with allogenic CD4(+)CD45RA(+) naïve T cells from healthy donors. Mucosal healing was investigated in epithelial wounding and migration assays with IEC-6 cells. SbS significantly decreased the frequency of CD40-, CD80-, and CD197 (CCR7; chemokine receptor-7)-expressing IBD mDC and reduced their secretion of tumor necrosis factor (TNF)-α and interleukin (IL)-6 while increasing IL-8. In the MLR, SbS significantly inhibited T cell proliferation induced by IBD mDC. Moreover, SbS inhibited T(H)1 (TNF-α and interferon-γ) polarization induced by UC mDC and promoted IL-8 and transforming growth factor-ß-dependent mucosal healing. In summary, we provide novel evidence of synergistic mechanisms how Sb controls inflammation (inhibition of T cell costimulation and inflammation-associated migration and mobilization of DC) and promotes epithelial restitution relevant in IBD.

Developing a vaccine against aspergillosis.

Although there is considerable experimental data to support the idea, bringing a fungal vaccine to fruition has been elusive. Moreover, vaccinating the immunocompromised, susceptible to an opportunistic disease such as invasive aspergillosis, seems formidable. However, pioneering studies using Aspergillus particulate forms or homogenates, and recently, recombinant proteins, have demonstrated feasibility. Moreover, T cell receptors also recognize glycotopes if presented in the appropriate MHC-binding context. The potential role of induced antibody has been appreciated only recently. Recent studies in our laboratory with heat-killed Saccharomyces (HKY) have raised the possibility of development of a panfungal vaccine. This yeast may be nature's experimental reagent, to show the way to a protective protein-carbohydrate conjugate vaccine. Subcutaneous HKY is an effective vaccine against Aspergillus, Coccidioides or Candida challenge. We have learned the protective moiety is in the cell wall, and proteins, glucan and lipid all seem important. We have also found the cell wall glycans alone, mannan or glucan, as a vaccine each provide significant protection. This leads to consideration of the importance of glycosylated proteins and glycan polymer-protein conjugates in vaccine development. We think the most productive route to a fungal-specific vaccine may be a conjugate vaccine that combines the optimally configured glycan with a specific immunogenic protein. Our work so far suggests that some proteins may be sufficiently cross-immunogenic, such that combined with the appropriate glycan, it may be possible to develop a pan-fungal vaccine.

Immunostimulatory activity of potential probiotic yeast strains in the dorsal air pouch system and the gut mucosa.

AIMS: To determine the immunostimulatory activity of 15 presumptive probiotic yeast strains in the dorsal air pouch system in comparison with their activity in the gut mucosa. METHODS AND RESULTS: Presumptive probiotic yeast strains previously isolated from human gastrointestinal tract and Feta cheese were further characterized genotypically and biochemically. The Saccharomyces cerevisiae 982, Saccharomyces boulardii KK1 and Kluyveromyces lactis 630 strains exhibited in the air pouch increased polymorphonuclear cell influx and phagocytic activity as well as cytokine production with similar potency as the probiotics Ultra levure S. boulardii and Lactobacillus acidophilus NCFB 1748. Oral administration of these strains in mice results in differential activation of small intestine immune responses concerning IgA and cytokine production as well as Toll-like receptor expression. CONCLUSION: Besides the Saccharomyces strains 982 and KK1, the K. lactis 630 strain could also be considered as a candidate probiotic. SIGNIFICANCE AND IMPACT OF THE STUDY: The air pouch model may be used as an alternative and rapid method for the discrimination and selection of potential probiotic yeast strains.

Saccharomyces boulardii inhibits lipopolysaccharide-induced activation of human dendritic cells and T cell proliferation.

Saccharomyces boulardii (Sb) is a probiotic yeast preparation that has demonstrated efficacy in inflammatory and infectious disorders of the gastrointestinal tract in controlled clinical trials. Although patients clearly benefit from treatment with Sb, little is known on how Sb unfolds its anti-inflammatory properties in humans. Dendritic cells (DC) balance tolerance and immunity and are involved critically in the control of T cell activation. Thus, they are believed to have a pivotal role in the initiation and perpetuation of chronic inflammatory disorders, not only in the gut. We therefore decided to investigate if Sb modulates DC function. Culture of primary (native, non-monocyte-derived) human myeloid CD1c+CD11c+CD123(-) DC (mDC) in the presence of Sb culture supernatant (active component molecular weight < 3 kDa, as evaluated by membrane partition chromatography) reduced significantly expression of the co-stimulatory molecules CD40 and CD80 (P < 0.01) and the DC mobilization marker CC-chemokine receptor CCR7 (CD197) (P < 0.001) induced by the prototypical microbial antigen lipopolysaccharide (LPS). Moreover, secretion of key proinflammatory cytokines such as tumour necrosis factor-alpha and interleukin (IL)-6 were notably reduced, while the secretion of anti-inflammatory IL-10 increased. Finally, Sb supernatant inhibited the proliferation of naive T cells in a mixed lymphocyte reaction with mDC. In summary, our data suggest that Sb may exhibit part of its anti-inflammatory potential through modulation of DC phenotype, function and migration by inhibition of their immune response to bacterial microbial surrogate antigens such as LPS.

Comparative study of Bifidobacterium animalis, Escherichia coli, Lactobacillus casei and Saccharomyces boulardii probiotic properties.

The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.

Effects of Saccharomyces boulardii on cytokine secretion from intraepithelial lymphocytes infected by Escherichia coli and Candida albicans.

Saccharomyces boulardii (S. boulardii) is a probiotic and used in the prevention or treatment of diarrhoea. Saccharomyces boulardii has many mechanisms to protect the host against diarrhoeal pathogens. It might modulate the immune system. In this study, the influence of S. boulardii on the secretion of cytokines from intraepithelial lymphocytes (IELs) infected with Escherichia coli (E. coli) and Candida albicans (C. albicans) was investigated in vitro. Cytokine levels were determined by enzyme-linked immunosorbent assay. The secretion of proinflammatory cytokines such as interleukin (IL)-1beta was decreased in the infected IELs incubated with S. boulardii, but different from it, anti-inflammatory cytokine levels such as IL-4 and IL-10, however, were found to be higher. These findings demonstrated that S. boulardii may have protective effects against diarrhoeal pathogens by reducing the proinflammatory response.

A randomized, open trial evaluating the effect of Saccharomyces boulardii on the eradication rate of Helicobacter pylori infection in children.

AIM: The failure rate of Helicobacter pylori (H. pylori) eradication imposes the assessment of new options. SUBJECTS AND METHODS: A prospective open study was performed in 90 symptomatic children (range 3-18 years) with H. pylori infection, randomized in two groups: control (42 patients) and intervention group (48 patients). Both groups were treated with the standard triple eradication therapy (omeprazole/esomeprazole, amoxicillin and clarithromycin) for 7-10 days. The intervention group was also treated with Saccharomyces boulardii (S. boulardii), 250 mg b.i.d., for 4 weeks. The eradication rate of H. pylori was assessed by the same methods (urease test and histology) 4-6 weeks after treatment. Adverse events and compliance were evaluated after 7 and 28 days of treatment. The Chi-square test was used for statistical evaluation (p < 0.05). RESULTS: H. pylori infection was identified in 90 of 145 children (62%) and it correlated positively with age (p < 0.002) and inversely with socioeconomic status (p < 0.005). All infected children had chronic gastritis, with antral nodularity in 76.7%. Overall, H. pylori eradication rate was 87.7% (control 80.9%, S. boulardii group 93.3%) (p = 0.750). The incidence of side effects was reduced in the S. boulardii group: 30.9% in the control versus 8.3% in the probiotic group (p = 0.047). CONCLUSION: The addition of S. boulardii to the standard eradication treatment confers a 12% nonsignificant enhanced therapeutic benefit on H. pylori eradication and reduces significantly the incidence of side effects.

The pattern recognition receptors dectin-2, mincle, and FcRγ impact the dynamics of phagocytosis of Candida, Saccharomyces, Malassezia, and Mucor species.

Phagocytosis is a receptor-mediated process critical to innate immune clearance of pathogens. It proceeds in a regulated sequence of stages: (a) migration of phagocytes towards pathogens, (b) recognition of PAMPs and binding through PRRs, (c) engulfment and internalisation into phagosomes, (d) phagosome maturation, and (e) killing of pathogen or host cells. However, little is known about the role that individual receptors play in these discrete stages in the recognition of fungal cells. In a previous study, we found that dectin-2 deficiency impacted some but not all stages of macrophage-mediated phagocytosis of Candida glabrata. Because the C-type lectin receptor dectin-2 critically requires coupling to the FcRγ chain for signalling, we hypothesised that this coupling may be important for regulating phagocytosis of fungal cargo. We therefore examined how deficiency in FcRγ itself or two receptors to which it couples (dectin-2 and mincle) impacts phagocytosis of six fungal organisms representing three different fungal taxa. Our data show that deficiency in these proteins impairs murine bone marrow-derived macrophage migration, engulfment, and phagosome maturation, but not macrophage survival. Therefore, FcRγ engagement with selective C-type lectin receptors (CLRs) critically affects the spatio-temporal dynamics of fungal phagocytosis.

Role of ASCA and the NOD2/CARD15 mutation Gly908Arg in predicting increased surgical costs in Crohn's disease patients: a project of the European Collaborative Study Group on Inflammatory Bowel Disease.

BACKGROUND: NOD2/CARD15, the first identified susceptibility gene in Crohn's disease (CD), is associated with ileal stenosis and increased frequency of surgery. Anti-Saccharomyces cerevisiae antibody (ASCA), a serological marker for CD, is associated with ileal location and a high likelihood for surgery. We hypothesized that the presence of ASCA and NOD2/CARD15 mutations could predict increased health care cost in CD. METHODS: CD patients in a prospectively designed community-based multinational European and Israeli cohort (n = 228) followed for mean 8.3 (SD 2.6) years had blood drawn for measurement of ASCA (IgG, IgA), Arg702Trp, Gly908Arg, and Leu1007fsinsC. Days spent in the hospital and the costs of medical and surgical hospitalizations and medications were calculated. RESULTS: The median duration of surgical hospitalizations was longer in Gly908Arg-positive than -negative patients, 3.5 and 1.5 days/patient-year (P < 0.01), and in ASCA-positive than -negative patients, 1.1 and 0 days/patient-year (P < 0.001). Median surgical hospitalization cost was 1,580 euro/patient-year in Gly908Arg-positive versus 0 euro/patient-year in -negative patients (P < 0.01), and 663 euro/patient-year in ASCA-positive versus 0 euro/patient-year in -negative patients (P < 0.001). Differences in cost of medications between groups were not significant. The effect of Gly908Arg was expressed in countries with higher Gly908Arg carriage rates. ASCA raised surgical costs independently of the age at diagnosis of disease. Arg702Trp and Leu1007fsinsC did not affect the cost of health care. CONCLUSIONS: Since CD patients positive for Gly908Arg and ASCA demonstrated higher health care costs, it is possible that measurement of Gly908Arg and ASCA at disease diagnosis can forecast the expensive CD patients.

Orally Administrated Whole Yeast Vaccine Against Porcine Epidemic Diarrhea Virus Induced High Levels of IgA Response in Mice and Piglets.

The mucosal immune response against the porcine epidemic diarrhea virus (PEDV) is very important in piglets. To develop a PEDV vaccine suitable for inducing high levels of intestinal IgA in piglets, recombinant yeast expressing the PEDV S1 gene was constructed and tested by oral immunization of mice and piglets. The S1-specific IgG and IgA were tested at 0, 14, and 28 days postimmunization (dpi) in mice. Compared to the control group, the mice treated with S1 expressing yeast, demonstrated significantly higher levels of IgG and IgA against PEDV from 14 dpi onward. The recombinant yeast inducing a fecal IgA response in piglets was also tested. PEDV-specific IgA could be detected at 7 dpi and increased to 28 dpi. We demonstrated that whole recombinant yeast can be used as a PEDV vaccine vector for inducing high levels of IgA against PEDV in piglets. This could be a good vaccine candidate for PEDV control in piglets.

A Randomized Clinical Trial Evaluating the Effects of Oligosaccharides on Transfer of Passive Immunity in Neonatal Dairy Calves.

BACKGROUND: Bacterial contamination of colostrum is common and can decrease IgG absorption in neonatal calves. Strategies that mitigate this situation without complicating colostrum management will benefit dairy calf health and survival. OBJECTIVES: To evaluate the effects of supplementing colostrum with oligosaccharides (OS) on serum IgG concentration and apparent efficiency of absorption of IgG (AEA%) in calves fed unpasteurized colostrum and characterize these outcomes with respect to colostrum bacterial exposures. ANIMALS: One hundred twenty-three neonatal dairy calves. METHODS: Randomized, blinded, controlled clinical trial conducted at a commercial dairy operation. Calves were enrolled at birth in 1 of 4 treatment groups. Data were complete for 123 calves, which were distributed across the treatment groups as follows: mannan-oligosaccharides (MOS), n = 33; Saccharomyces galacto-oligosaccharides (SGOS), n = 31; Bifidobacterium galacto-oligosaccharides (BGOS), n = 28; and lactose control (CON), n = 31. A commercial radial immunodiffusion kit was used to determine colostrum and serum IgG concentrations. Conventional microbiology methods were used to enumerate colostrum bacterial counts. RESULTS: Bacterial counts were not significantly different among treatment groups. Total bacterial plate counts (TPC) were relatively low for the majority of colostrum samples, but TPC had a significant negative effect on serum IgG concentration and AEA% in the lactose-supplemented control group but not the OS treatment groups. CONCLUSIONS AND CLINICAL IMPORTANCE: These results suggest that a complement of OS structures may mitigate adverse effects of bacteria on transfer of passive immunity (TPI).

Inflammatory bowel diseases and Takayasu's arteritis: coincidence or association?

BACKGROUND: Takayasu's arteritis (TA) and inflammatory bowel disease (IBD) are rare diseases but there are case reports presenting their co-existence in the literature. The aim of this study was to investigate the relation between IBD and TA. METHODS: We studied 52 consecutive TA patients (90.3% female); medical records of the patients were analyzed retrospectively and serum samples were taken during the control visits for anti-neutrophil cytoplasmic antibody (ANCA) and anti-saccharomyces antibody (ASCA) tests. RESULTS: Overall three (5.8%) of 52 patients had both IBD and TA. All were first diagnosed as IBD and the period between the diagnosis of IBD and TA was 9, 30 and 60 months, respectively. The age at diagnosis of TA was younger for the patients with IBD as compared to TA patients without IBD, but the difference was not statistically significant. Two patients had type-5 and one had type-2a TA. In 92 participants (52 with TA and 40 healthy controls) none had positive results for ANCA or ASCA. CONCLUSION: Anti-saccharomyces antibody and ANCA tests are not useful for predicting the association between TA and IBD. On the other hand, both diseases have similar patient characteristics and pathophysiology which make us suspect that there may be an interaction. If a patient with IBD under immunosuppressive treatment has ongoing symptoms such as fever, weight loss, hypertension or high acute phase reactants, TA may be the cause. Further trials are needed but their coexistence cannot be explained as incidental.

Sensing microorganisms in the gut triggers the immune response in Eisenia andrei earthworms.

The tube-within-tube body plan of earthworms is appropriate for studying the interactions of microorganisms with the immune system of body cavities such as the digestive tract and coelom. This study aims to describe the immune response on the molecular and cellular level in the coelomic cavity and the gut of the earthworm Eisenia andrei after experimental microbial challenge by administering two bacterial strains (Escherichia coli and Bacillus subtilis) or yeast Saccharomyces cerevisiae to the environment. The changes in mRNA levels of defense molecules (pattern recognition receptor CCF, lysozyme, fetidin/lysenins) in the coelomocytes and gut tissue were determined by quantitative PCR. The immune response at a cellular level was captured in histological sections, and the expression of CCF was localized using in situ hybridization. Coelomocytes respond to the presence of bacteria in the coelomic cavity by increasing the mRNA levels of defense molecules, especially CCF. The immune response in gut tissue is less affected by microbial stimulation because the epithelial cells of gut exhibit basically strong mRNA synthesis of ccf as a defense against the continuous microbial load in the gut lumen. The cellular immune response is mediated by coelomocytes released from the mesenchymal lining of the coelomic cavity. These combined immune mechanisms are necessary for the survival of earthworms in the microbially rich environment of soil.

A murine monoclonal antibody directed against a yeast cell wall glycoprotein antigen of the yeast genus Saccharomyces.

Murine monoclonal antibodies (mAbs) were selected against a cell wall glycoprotein of Saccharomyces cerevisiae. One of the mAbs (92-276/018) specifically identified S. cerevisiae and the sibling species S. paradoxus, S. pastorianus and S. bayanus in immunofluorescence studies and immunoblot analyses, while no other yeast genera except Saccharomyces were recognized. Further analysis indicated that the mAb 92-276/018 reacts with an epitope in the carbohydrate chain of the cell wall glycoproteins.

Stably inherited killer activity in industrial yeast strains obtained by electrotransformation.

Killer-sensitive strains of Saccharomyces cerevisiae and Saccharomyces carlsbergensis were transformed by electroinjection using double-stranded RNA isolated from a superkiller strain. Various recipient strains were used: both thermo-resistant and thermo-sensitive as well as mutants of industrial strains. Conversion of respiratory competent (rho+) into respiratory deficient (rho-) strains (mutants) resulted in a significant increase of the yield of electrotransformants and/or of longterm killer stability. Electrotransformation of rho- mutants of distillery and brewery strains resulted in more than 100 clones, which exhibited weak or strong killer activity over some or all of the experimental period of 10 months.

Toxicity of domoic acid in the marine mussel Mytilus edulis.

The neurotoxic, immunotoxic and genotoxic effects of domoic acid (DA) on the blue mussel Mytilus edulis were investigated by biomarkers, acethylcholinesterase (ChE) activity in gills, DNA fragmentation in digestive glands, vitality and phagocytosis activity of haemocytes in haemolymph of mussels. After intra muscular injection of DA at the concentrations ranging from 1-500 ng/g body weight (bw), no neurotoxic effect was detected within incubation times of 48 h and 7 d. The vitality of haemocytes remained in all mussels at the level of control samples within 48 h, and increased significantly after 7 d (P<0.05). At DA concentrations ranging from 1 to 100 ng/g bw haemocytes suggested a great phagocytosis activity, but no alteration in their number by both incubation times. By increasing DA concentration of 500 ng/g bw, the number of haemocytes doubled in 48 h without any change in phagocytosis activity. Primary DNA lesions in digestive glands of all injected mussels were determined in acute phase of poisoning within 48 h, and rapidly repaired after 7 d of incubation.