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At least 19 recordsLinked to original sources
PubMed2026

Characterization and functional insights of histone deacetylases in bivalves: implications for temperature and immune response in Chlamys nobilis.

Histone deacetylases serve as pivotal epigenetic regulators that modulate chromatin remodeling and gene transcription, playing critical roles in immune defense and environmental stress responses in aquatic organisms. However, the evolutionary characteristics and functional roles of the HDAC family in bivalves remain poorly understood. In this study, genome-wide identification of the HDAC family across 30 bivalve species yielded 558 HDAC genes. Phylogenetic reconstruction categorized these genes into four conserved groups and revealed a unique, bivalve-specific SIRT8 clade. Using the noble scallop Chlamys nobilis as a representative model, expression profiling revealed distinct expression patterns among CnHDAC members. Class I and most Class III members were predominantly expressed in the gonads, while Class II members were enriched in immune-related tissues, implying their potential involvement in bivalve immunity. Upon temperature stress, CnHDAC1/2, CnHDAC11-1, CnHDAC11-2, CnSIRT2-1, CnSIRT4, CnSIRT6, and CnSIRT8-3 were significantly induced, highlighting their critical roles in temperature adaptation. Upon Vibrio exposure, CnHDAC1/2, CnHDAC8, CnSIRT4, and CnSIRT6 were upregulated, while CnHDAC4/5/7/9, CnHDAC6/10, CnSIRT2-2, CnSIRT5, CnSIRT7, and CnSIRT8-3 were downregulated, suggesting a coordinated epigenetic regulatory mechanism underlying host immune defense. In conclusion, this study systematically elucidates the evolutionary landscape of the HDAC family and underscores its potential involvement in environmental resilience and host immunity, providing a theoretical basis for the breeding of disease-resistant and stress-tolerant aquaculture bivalves.

Animals↗
PubMed2026

Evolutionary expansion of the NF-Y gene family in bivalves and divergent subunit responses to thermal and pathogenic stress in the noble scallop.

Nuclear factor Y (NF-Y) is a conserved eukaryotic transcription factor complex that specifically interacts with the CCAAT motif. Prior research has demonstrated that this gene family participates in various biological processes, encompassing growth, development, and stress responses, across a broad spectrum of organisms. However, research on the role of the NF-Y family in bivalves remains limited. In this study, we comprehensively identified the NF-Y family in 34 bivalve species, and further investigated its expression in the noble scallop Chlamys nobilis. A total of 296 NF-Y genes were identified and classified into three subfamilies, NF-YA, NF-YB, and NF-YC. Phylogenetic analysis revealed that NF-YA and NF-YC have remained relatively conserved, whereas NF-YB has undergone significant expansion. Additionally, while substantial disparities in gene copy numbers exist across species, the motif composition and exon-intron structures within each subfamily demonstrate notable conservation. Tissue expression profiling revealed distinct expression patterns among CnNF-Y genes, with several members exhibiting relatively high transcript abundance in gonadal tissues. Furthermore, qRT-PCR results demonstrated that CnNF-YA2, CnNF-YB6, and CnNF-YC were significantly and continuously upregulated under heat stress. Conversely, several genes, particularly CnNF-YA2, CnNF-YB3, and CnNF-YB4, exhibited dynamic transcriptional responses to Vibrio parahaemolyticus exposure. These findings enhance our understanding of the evolutionary trajectory and functional diversification of the NF-Y gene family in bivalves, laying a theoretical foundation for future research on thermal adaptation, immune regulation, and molecular breeding in scallops.

Animals↗
PubMed1979

Adsorption and growth of Vibrio cholerae on chitin.

Incubation of Vibrio cholerae of O-group serotype 1 with chitin particles resulted in adsorption of vibrios onto chitin; chitin-adsorbed V. cholerae survived exposure to acid better than nonadsorbed vibrios. V. cholerae multiplied in dialyzed chitin suspended in 4.2% NaCl, suggesting that adherence to ingested chitin of crustacea might be of epidemiological significance by providing a substrate for vibrio multiplication as well as protection from gastric acid during stomach transit.

Acids↗
PubMed1978

Non-cholera vibrio infections in the United States. Clinical, epidemiologic, and laboratory features.

Non-cholera vibrios are organisms that are biochemically indistinguishable from Vibrio cholerae but do not agglutinate in vibrio 0 group 1 antiserum. Since 1972 there has been a dramatic increase in the number of these organisms referred to the Center for Disease Control for identification. Clinical, epidemiologic, and laboratory data were analyzed for 26 of 28 patients with isolates identified between January 1972 and March 1975. Thirteen (50%) of the isolates were obtained from feces of patients who had an acute diarrheal illness; no other pathogens were isolated from their feces, and all patients survived. Four (15%) patients had non-cholera vibrios isolated from other gastrointestinal or biliary tract sites; none of these patients had acute illness definitely attributable to non-cholera vibrios. Nine (35%) patients had non-cholera vibrios isolated from other tissues and body fluids; four deaths occurred in this group. Patients with acute diarrhea frequently had a history of recent shellfish ingestion or foreign travel, whereas some patients with systemic non-cholera vibrio infection had a history of recent occupational or recreational exposure to salt water.

Adolescent↗
PubMed1977

Neuraminidase- and trypsin-induced exposure to membrane receptors for IgG and IgM molecules on human peripheral blood lymphocytes.

Brief incubation of human peripheral blood lymphocytes with vibrio cholerae neuraminidase (VCN) or trypsin revealed hidden membrane receptors for IgG and IgM molecules. The hidden receptors were found on T lymphocytes as shown by double-label and mixed rosetting experiments and by studies of T-enriched populations. Although IgM receptors were undetectable on freshly isolated lymphocytes, a mean of 17.1% of VCN-treated lymphocytes rosetted with ox erythrocytes coated with IgM antibody (EA-IgM). Prior to trypsin treatment a mean of 14.6% of human T lymphocytes rosetted with ox red cells coated with IgG antibody (EA-IgG). After incubation with trypsin this figure increased significantly (P less than 0.005) to 44.5%. VCN-treatment also significantly increased (P less than 0.005) the mean percentage of EA-IgG rosette-forming T cells to 38.5%. The T-cell receptor for IgG was shown to be trypsin-resistant while the IgM receptor was shown to be trypsin-sensitive. Using mixed rosettes, a tentative T-cell subset was identified which expressed both IgG and IgM membrane receptors. Also, a minor subset with IgM receptors alone and a larger subset with only IgG receptors were identified.

Binding Sites, Antibody↗
PubMedDate not supplied

Antibodies in human serum and milk induced by enterobacteria and food proteins.

Ingestion of Escherichia coli O83 bacteria by adults resulted in a transient irregular colonization leading to a serum antibody response in only four out of 14 cases examined. In all of three pregnant women, however, IgA antibodies against E. coli O83 antigen were released from colostral cells after similar bacterial ingestion although no serum antibody response was noted. The findings indicate a link between the antigenic exposure to the gut and secretory antibodies of the IgA class, presumably locally formed in the mammary gland. Antibodies of the secretory IgA class registered in colostrum may, at least partly, reflect the antigenic exposure of the gut. These antibodies are probably important in protecting against E. coli infections in the neonate, as suggested by the findings of antibodies in human milk against O and K antigens of non-enteropathogenic as well as enteropathogenic serotypes of E. coli. Furthermore, in milk of women from low socio-economic groups in Pakistan, neutralizing antibodies were present against enterotoxins of E. coli bacteria and occasionally against Vibrio cholerae enterotoxins. In addition, secretory IgA antibodies against food proteins were detected in human milk. This suggests that intestinal exposure to such antigens could stimulate a local immune response in the gut resulting in triggered lymphoid cells homing to the mammary gland. These human milk secretory IgA antibodies against bovine milk proteins may help to prevent cow's milk allergy in infants on mixed feeding, since these infants tend to have a lower serum antibody response to cow's milk proteins than infants fed mostly artificially. Furthermore, children suffering from cow's milk protein intolerance and gluten enteropathy may have higher serum levels of antibody to cow's milk protein antigens than normal children, possibly reflecting increased permeability of the intestinal mucosa for various antigens.

Adult↗
PubMed1979

Disease caused by a marine Vibrio. Clinical characteristics and epidemiology.

We studied the clinical characteristics and epidemiology of disease associated with a rare, unnamed halophilic lactose-fermenting Vibrio species in 39 persons from whom the organism had been isolated. Two distinct clinical presentations were seen. In the first, the illness began with septicemia, often within 24 hours after raw oysters had been eaten; 18 of 24 such patients had pre-existing hepatic disease, and 11 of the 24 died. In the second, there was a wound infection after exposure to seawater or an injury incurred during the handling of crabs; none of these persons had pre-existing hepatic disease, and one of 15 died. Most cases (85 per cent) occurred during relatively warm months (May to October) in men (90 per cent) 40 or more years of age (95 per cent). This Vibrio species is a pathogen and should be considered in the differential diagnosis of septicemia with secondary skin lesions and of wound infections after exposure to seawater.

Adult↗
PubMed1977

Intestinal fluid accumulation induced by oral challenge with Vibrio cholerae or cholera toxin in infant mice.

The diarrheal response of orally inoculated infant mice to viable Vibrio cholerae and purified cholera toxin was quantitated by means of a fluid accumulation (FA) ratio. The FA ratio is defined as the gut weight/remaining body weight. FA ratios were determined in relation to time of exposure and dose. Onset of fluid accumulation with viable cells of strains CA401 and 569B occurred 8 h postinoculation and reached a near maximum of 16 h. A dose of 4 x 10(6) colony-forming units of strain CA401 was required for a positive response 16 to 18 h postinoculation. Several other classical cholera strains demonstrated a similar dose-related response. Strain 569B, however, required a 100-fold higher dose to give a positive response. Several mutant cholera strains were decreased virulence in other model systems elicited FA ratios decreased from wild-type values. Onset of fluid accumulation which cholera toxin occurred 6 to 8 h postinoculation and reached a maximum by 10 h. A dose of 0.5 microng was required for a positive response 10 to 12 h postinoculation. The positive response to toxin could be inhibited by preincubation with specific antitoxin.

Animals↗
PubMed1976

Neutralizing antibodies against Escherichia coli and Vibrio cholerae enterotoxins in human milk from a developing country.

By means of the adrenal cell assay and the rabbit small-bowel loop technique enterotoxin-neutralizing antibodies were demonstrated in all investigated milk samples from severely undernourished Pakistani women but, with a single exception, not in milk from Swedish mothers. The antibodies belonged to the IgA and IgG classes as observed in an enzyme-linked immunosorbent assay, which also revealed secretory component on specific enterotoxin antibodies, showing that the IgA antibodies were primarily of the secretory type. The epidemiological stituation and experimental data strongly indicate that Escherichia coli enterotoxin rather than immunologically cross-reactive Vibrio cholerae toxin in most cases constituted the antigenic stimulus for the milk antibodies. The presence in the milk of the Pakistani mothers of secretory IgA antibodies against an important diarrheogenic agent may have practical importance for protection of the breast-fed baby and probably also illustrates the frequent intestinal exposure of these women to enterotoxinogenic bacteria. Since enterotoxin antigen is presumed not to enter deeper tissues, the demonstration of secretory antibodies in milk agrees with a proposed homing of intestinally triggered lymphocytes to the mammary gland.

Antibodies, Bacterial↗
PubMed1979

An ultraviolet light induced bacteriophage in Beneckea gazogenes.

An ultraviolet light induced prophage has been discovered in the red pigmented marine vibrio Beneckea gazogenes. Two spontaneously derived pigment mutants, one forming pink colonies and one lacking pigment and forming white colonies, were also irradiated. The presence of pigment was not related to phage induction; uv-induced cell lysis occurred in wildtype and mutant strains at the same dosages. Lysis was not prevented or retarded by exposure after irradiation to visible light indicating the phenomenon was not photoreactivable. Electron micrographs of the 'T-like' B. gazogenes phage are shown. A second beneckea was isolated form the anaerobic zone of cyanobacterial mats growing in the hypersaline environment of Laguna Mormona, Baja California. The Baja beneckea does not harbor a uv inducible prophage and is resistant to the B. gazogenes phage under all conditions tested.

Bacteriolysis↗
PubMed1975

Lanthanum inhibition of Vibrio cholerae and Escherichia coli enterotoxin-induced enterosorption and its effects on intestinal mucosa cyclic adenosine 3',5'-monophosphate and cyclic guanosine 3',5'-monophosphate levels.

Several trivalent cations, including lanthanum (La3+), inhibited the secretion (enterosorption) induced by the enterotoxins of Vibrio cholerae and Escherichia coli in the rabbit ileum in vivo. High concentrations (greater than 10 mM) of La3+ were required to inhibit cholera enterotoxin (CE)-induced enterosorption, probably because of the adsorption of the La3+ often potentiated the CE-induced enterosorption. If luminal La3+ exposure followed CE exposure, some recovery of the enterosorptive response was observed. The longer the lag between the CE exposure and the La3+ exposure, the greater was the recovery of the enterosorptive response. Lanthanum inhibited HCO3- secretion more than Cl- secretion. By altering the luminal fluid pH at the time of La3+ exposure, it was found that La3+ was adsorbed to negatively charged luminal sites, having an apparent pK between 2.5 and 3.0. Although La3+ antagonized the enterosorptive response to CE, it mimicked rather than antagonized the cyclic adenosine 3',5'-monophosphate elevation and cyclic guanosine 3',5'-monophosphate depression induced by the toxin. It is therefore concluded that the La3+ inhibition of the CE-induced enterosorption must have occurred at a site following the generation of the cyclic nucleotides. Cholera enterotoxin caused complex time-dependent changes in the mucosal cyclic adenosine 3',5'-monophosphate and cyclic guanosine 3',5'-monophosphate levels, as revealed by studying tissue cyclic adenosine 3',5'-monophosphate/cyclic guanosine 3',5'-monophosphate ratios. The possible roles these two cyclic nucleotides may play in the pathogenesis of the cholera diarrhea are discussed.

Animals↗
PubMed1978

Evidence of acquired immune deficiencies in Mediterranean lymphoma. A possible aetiological link.

Patients with Mediterranean lymphoma (M.L.) had a significant reduction in humoral immunity (IgG and IgM) as well as impaired cellular immunity (50% were anergic to three antigens--P.P.D., mumps, and dinitrochlorobenzene). Any hypothesis for the pathogenesis of M.L. has to account for the peculiar geographic distribution of the disease, the age and sex incidence, the plasma-cell nature of the tumours, the associated heavy plasmacytic proliferation with relatively intact intestinal mucosa, involvement of the proximal small intestine, and alpha-chain production in a large proportion of patients. All areas in which M.L. is common are currently involved in the seventh cholera pandemic. Vibrio cholerae toxin inhibits both immediate and delayed immune reaction in vitro through its effect on cyclic adenosine monophosphate. V. cholerae antigens stimulate the proliferation of IgA-producing immunocytes in the mucosa without deeply penetrating the mucosa. The proximal small bowel is usually affected by the disease but there is little epithelial damage. The population in endemic areas is continuously exposed to V. cholerae antigens and toxins. It is suggested that such exposure, under certain genetic or other circumstances, may produce a state of immunosuppression in the gut thus accelerating, predisposing to, or producing lymphoplasmacytic neoplasia.

Antigens, Bacterial↗
PubMed1977

Suitability of some enrichment broths and diluents for enumerating cold- and heat-stressed Vibrio parahaemolyticus.

Vibrio parahaemolyticus cells were injured by chilling and heating, and their recovery was tested in glucose-salt-Teepol broth (GSTB), tryptic soy broth containing 7% NaCl (TSBS), Horie - arabinose - ethyl violet broth (HAEB), and water blue - alizarin yellow broth (WBAY). Exponential phase cells were more sensitive to cold shock than were stationary phase cells. Exposure of chill-injured V. parahaemolyticus to GSTB and TSBS resulted in 70 to 80% death; about 70% lethality was noted for heat-injured cells inoculated into TSBS. Neither HAEB nor WBAY enrichment media were lethal to stressed cells, although rates of growth were retarded. The 3% NaCl in 0.1 M potassium phosphate (pH 7.0) diluent proved to be most suitable for protecting against inactivation of cold- and heat-injured cells.

Cold Temperature↗
PubMed1977

Lysis of halophilic Vibrio alginolyticus and Vibrio costicolus induced by chaotropic anions.

High concentration (1.0 M) of KSCN, but not of NaSCN, induced lysis of slightly halophilic Vibrio alginolyticus and moderately halophilic Vibrio costicolus, and the decrease in absorbance of the cell suspension was complete after 30 min at 25 degrees C. Replacement of K+ with Na+ effectively prevented the lysis by SCN-.K+ salts of NO3-, Br- and I-, however, induced no significant lysis. In electron micrographs, a prolonged exposure of the cells of V. alginolyticus to 1.0 M KSCN displaced the nucleoplasm to maintain close contact with the cell membranes. After 40 min of interaction, 50% of the cellular protein, 96% of RNA and 94% of DNA were recovered in the lysed cells. In contrast to lysis in hypotonic conditions, the lysis induced by KSCN is due mainly to a partial release of protein from the cells. V. costicolus was more susceptible to SCN- than V. alginolyticus, whereas nonhalophilic Escherichia coli was resistant to 1.0 M KSCN. Thus, lysis by SCN- is characteristic of halophilic bacteria and cell membranes of more halophilic bacteria are more susceptible to chaotropic anions. The protective effect of Na+ observed here was considered to be manifested by specific interactions of Na+ with components of cell membranes, thereby rendering their structures resistant to the action of chaotropic anions.

Bacteriolysis↗
PubMed1976

Effect of cholera enterotoxin preparations on cutaneous response in rabbit under varied conditions.

Enterotoxic activity of two preparations obtained from Vibrio cholerae, B-53-6 Inaba and B-53-10 Ogawa was tested in ligated ileal loops of rabbit. The biologically active enterotoxic preparations were further used to study the permeability reaction in rabbit skin. Cutaneous response tended to be linear only with higher concentrations of the toxin and showed maximum blueing intensity between 16 and 24 hrs of intracutaneous inoculation. Exposure of enterotoxin preparations to elevated temperatures greatly reduced the cutaneous response and the activity was completely lost at 100 degrees C. Change in pH towards alkaline side lowered the permeability activity to lesser extent as compared to a shift on acidic side. However, a residual activity could still be detected when pH of the enterotoxins was lowered to 3 at 30 degrees C for 4 hrs.

Animals↗
PubMed1977

[Interaction of cholera vibrios and escherichiae with the intestinal epithelium (histologic and electron microscopic study)].

Histological and electron-microscopic investigations were carried out of ligated small intestinal loops of 147 rabbits within 24 hours after challenge with cholera vibrios El Tor, different enterotoxigenic E. coli, choleragen and E. coli enterotoxins. These ogranisms attached themselves to enterocytes and multiplied on the surface of the unaltered intestinal epithelium. Thereafter, a greatly pronounced secretion of enterocytes, rather than inflammation, developed, like after the exposure to sterile enterotoxins of E. coli and choleragen, the lumen of isolated rabbit gut loops was overfilled with great amount of fluid discharged. At later period dystrophic alterations in enterocytes also appeared. They were partly associated with excessive secretion, but the severest of them (including even necrotic foci) were caused by the compression of the isolated gut loops epithelium with fluid. The first and obligatory stage of pathogenesis of cholera and cholera-like escherichioses was apparently the attachment of the causative agent to enterocytes and its multiplication on the intestinal epithelium surface, followed by hypersecretion induced by enterotoxin effect.

Animals↗
PubMed1976

Challenge of dogs with live enterotoxigenic Escherichia coli and effects of repeated challenges on fluid secretion in jejunal Thiry-Vella loops.

Dogs were evaluated as experimental models for the study of diarrheal disease produced by enterotoxigenic Escherichia coli. Although a suitable whole model for orogastric bacterial challenge could not be developed, chronic jejunal Thiry-Vella loops were used to study the secretory effects of multiple jejunal challenges with enterotoxin of either Vibrio cholerae or E. coli. The heat-stable and heat-labile E. coli enterotoxins could be differentiated clearly in this model. Sequential weekly challenges over a four-week period showed a significant decrease in loop secretory response to homologous enterotoxin, although levels of antitoxin in serum remained unchanged, a finding suggesting a local immune response. Dogs challenged with E. coli enterotoxin were markedly protected against subsequent challenge with V. cholerae enterotoxin; the converse was not true. Histologic studies of the loops showed only minimal atrophy, and results of absorption studies in the loops were normal. These studies suggest that mongrel dogs are resistant to colonization by enterotoxigenic E. coli and partially resistant to challenge with enterotoxin, perhaps on an immune basis due to prior antigenic exposure. Multiple challenges with enterotoxin effect a decreased secretory response; this finding also suggests a local immune mechanism.

Animals↗