Chlorine and survival of "rugose" Vibrio cholerae.
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Animals↗
Biomedical subjects
J G Morris
Publications and source records attributed to J G Morris.
A serosurvey of pathogens associated with shellfish: prevalence of antibodies to Vibrio species and Norwalk virus in the Chesapeake Bay region.
Recent concerns regarding the safety of shellfish consumption have focused on the risk posed by naturally occurring marine bacteria such as Vibrio species and by viruses such as Norwalk and related agents. Despite the widespread environmental presence of Vibrio species in the Chesapeake Bay, the rate of reported infections remains low; there have also been no reports of major Norwalk outbreaks associated with shellfish in this area. As infections with these agents may not always be recognized because of difficulties in making the diagnosis and/or their mild or subclinical presentation, a serosurvey was conducted among healthy volunteers living in the Chesapeake Bay region. Serum and questionnaire data were collected during the fall of 1987 from 267 persons with varying levels of exposure to shellfish: shellfish industry workers, persons attending a local seafood festival, and Seventh-day Adventists (who traditionally abstain from eating shellfish). In comparisons among groups, a significant association could not be demonstrated between shellfish consumption or contact and antibody response to Vibrio cholerae O1 or Norwalk virus. Rates of seropositivity were high for both agents (up to 22% seropositive with a V. cholerae O1 Inaba vibriocidal assay, 14% with an enzyme-linked immunosorbent assay for cholera toxin, and up to 70% seropositive with an enzyme-linked immunosorbent assay for antibodies to Norwalk virus); the basis for these responses in population-based studies remains to be determined. Shellfish industry workers did have a significantly elevated antibody response to the unencapsulated phase variant of Vibrio vulnificus as compared with the other groups studied. Infection with V. vulnificus may be relatively common among persons with high levels of exposure to shellfish.
Adult↗
Recumbent tic.
A 59-year-old man with a 30-year history of an unusual movement disorder characterised by involuntary axial spasms that occur only in recumbency is described. Clinical and electrophysiological evidence suggest that this disorder is best characterised as a simple tic of unusual form. We have coined the term "recumbent tic" to describe this disorder.
Abdominal Muscles↗
Intestinal taurine and the enterohepatic circulation of taurocholic acid in the cat.
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Animals↗
Dilated cardiomyopathy associated with taurine deficiency in the domestic cat: relationship to diet and myocardial taurine content.
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Animals↗
Investigation of an outbreak of bloody diarrhea: association with endoscopic cleaning solution and demonstration of lesions in an animal model.
UNLABELLED: OUTBREAK INVESTIGATION: An outbreak of diarrhea, bloody diarrhea, and abdominal cramps occurred among persons undergoing flexible sigmoidoscopy at a branch clinic of a local health center. Illness was associated with use of sigmoidoscopes cleaned by one clinic assistant and appeared to be caused by 2% glutaraldehyde disinfectant solution left in the instruments after cleaning. ANIMAL STUDIES: In subsequent animal studies, colonic instillation of 2% glutaraldehyde solutions caused bloody diarrhea and a distinctive pattern of mucosal damage; similar changes were seen in a review of pathologic samples from other human cases of glutaraldehyde disinfectant-associated diarrhea. CONCLUSION: Our data indicate that improper endoscopic reprocessing can result in serious illness and underscore the importance of adequate training and quality control in this area.
Animals↗
Oral carrier vaccines: new tricks in an old trade.
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Administration, Oral↗
Taurine balance is different in cats fed purified and commercial diets.
Ileal fluxes, urinary losses and taurine balance were determined in six taurine-replete and four taurine-depleted cats. Digesta samples collected at the terminal ileum were used to assess ileal flux of taurine. Four diets were tested: a commercial diet in two forms (heat-processed and frozen) and two purified diets containing either 1225 or 0 mg taurine/kg diet. Five-day balance trials were performed on d 3-7 with measurement of food intake and taurine in urine and ileal digesta. Substantially greater quantities of total taurine (free + bound) were found in ileal digesta from cats fed the heat-processed rather than the frozen preserved diet (205 vs. 101% of the average daily taurine intake, respectively), with calculated taurine balances of -609 vs. -212 mumol/d, respectively. The quantity of taurine in ileal digesta from taurine-replete cats fed the 1225 or 0 mg taurine/kg purified diets was not significantly different, indicating that taurine found at the terminal ileum is mostly of endogenous origin. Taurine-depleted cats had significantly lower amounts of taurine in ileal digesta, with a taurine balance of -77 mumol/d. These results demonstrate that a heat-processed diet causes substantially greater losses of taurine from the intestine than does a frozen diet. This phenomenon may explain the inability of some heat-processed diets to maintain normal plasma taurine concentrations in cats.
Animal Feed↗
Dietary protein source (soybean vs. casein) and taurine status affect kinetics of the enterohepatic circulation of taurocholic acid in cats.
The effect of dietary protein source (soybean vs. casein) and taurine status on kinetics of [24-14C] and [taurine-2-3H]taurocholic acid was determined by isotope dilution in 10 adult male cats (six taurine-replete and four taurine-depleted). Taurine-replete cats were fed 1500 mg taurine/kg purified diets containing either 435 g/kg casein (1500 Cas) or soybean protein (1500 Soy) in a crossover design. Taurine-depleted cats were fed the soybean protein diet with no taurine (0 Soy). Specific activity of [14C]- and [3H]taurocholic acid in bile was determined for 6 d following a pulse dose of dual-labeled taurocholic acid. Taurocholic acid pool size was significantly greater in cats when fed the 1500 Soy diet than when fed the 1500 Cas or than in cats fed the 0 Soy diet. Total entry rate, irreversible loss rate and recycling rate of [taurine-2-3H]taurocholic acid and the irreversible loss rate of [24-14C]taurocholic acid tended to be greater in cats when fed the 1500 Soy than the 1500 Cas diet. Irreversible loss rates of taurocholic acid in taurine-replete cats fed the 1500 Soy diet were significantly greater than in taurine-depleted cats, 356 vs. 120 mumol/d [24-14C]taurocholic acid and 445 vs. 56 mumol/d [taurine-2-3H]taurocholic acid. The fraction of taurocholic acid was greater, and the fraction of taurochenodeoxycholic and taurodeoxycholic acids lower in cats when fed the 1500 Soy than when fed the 1500 Cas diet. Taurine-depleted cats had less taurocholic, taurochenodeoxycholic, and taurodeoxycholic acids and greater glycocholic and cholic acids than taurine-replete cats fed the 1500 Soy diet. This study demonstrates that both dietary protein source and taurine status affect taurocholic acid kinetics and bile acid composition in cats.
Animals↗
Neuropsychological abnormalities in patients with pituitary tumours.
Neuropsychological assessment of 65 patients with pituitary tumours revealed impairment of memory and executive function. This did not appear to be related to the size or type of tumour or the effects of radiotherapy or surgery. It is possible that the problems arose from multiple unconnected factors but this observation lends support to the suggestion that pituitary or hypothalamic hormones have a role in the modulation of memory and behavioural pathways. Whatever the cause, neuropsychological impairment is common in patients with pituitary tumours and is an aspect of their disability which has received insufficient attention in the past.
Adenoma↗
Use of colistin-polymyxin B-cellobiose agar for isolation of Vibrio vulnificus from the environment.
Colistin-polymyxin B-cellobiose agar was employed for the isolation of Vibrio vulnificus from shellfish. Isolates were examined phenotypically and with a gene probe and monoclonal antibody specific for V. vulnificus. Results indicated that colistin-polymyxin B-cellobiose agar is superior to both sodium dodecyl sulfate-polymyxin B-sucrose agar and thiosulfate-citrate-bile salts-sucrose agar in its ability to select and differentiate this species from background vibrios.
Agar↗
Human immune response to Campylobacter jejuni proteins expressed in vivo.
Campylobacter jejuni 81-176 grown in vivo in rabbit ileal loops expresses novel proteins that are not expressed under standard laboratory culture conditions. A new protein with a molecular mass of ca. 180 kDa is expressed at 14, 24, and 48 h of infection. Three other proteins, with molecular masses of ca. 66, 43, and 35 kDa, are overexpressed during different phases of infection. Expression of these proteins stops immediately during the first passage in laboratory media, and they do not elicit a human immune response. Two other proteins, with molecular masses of ca. 84 and 47 kDa, expressed 48 h after infection can be identified by using convalescent sera from human volunteers who were immune to C. jejuni infection upon rechallenge; these proteins were not visualized on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels by Coomassie blue staining or silver staining. Antibodies to the 84- and 47-kDa proteins are of the immunoglobulin G class. Both preinfection and convalescent human sera react strongly to the C. jejuni flagellin (a 58-kDa protein), suggesting the presence of cross-reactive antibodies to this protein in healthy humans. Major outer membrane protein and flagella may play a role in providing protection against C. jejuni disease, but our data suggest that there are other proteins expressed only during in vivo growth of the organism that elicit a strong immune response in human C. jejuni infections.
Animals↗
Non-O1 Vibrio cholerae intestinal pathology and invasion in the removable intestinal tie adult rabbit diarrhea model.
A modified removable intestinal tie adult rabbit diarrhea (RITARD) model was used to investigate the intestinal pathology, intestinal bacterial colonization, intestinal fluid volume, and onset of diarrhea caused by non-O1 Vibrio cholerae. Three strains of non-O1 V. cholerae were studied. RITARD rabbits challenged with 10(3) CFU of strain NRT36S (a strain previously shown to cause diarrhea in volunteers) developed grade 3 diarrhea at 48 to 72 h. The mean counts of non-O1 V. cholerae isolated were 9.3 +/- 0.07 and 8.7 +/- 0.7 CFU/g from the small and large intestines, respectively. Histologic examination showed necrosis of the luminal epithelium in the colon and mild inflammatory cell infiltration in the adjacent lamina propria. The severity and extent of intestinal damage by strain NRT36S was dose dependent. Higher doses of strain NRT36S caused severe necrotizing colitis and enteritis, with bacteremia and mortality at less than 24 h in RITARD rabbits challenged with 10(9) CFU and at less than 48 h in RITARD rabbits challenged with 10(4) CFU. Electron and light microscopy demonstrated invasion of NRT36S into the luminal epithelial cells of the intestine. Challenge of RITARD rabbits with non-O1 V. cholerae A-5 and 2076-79 (strains which did not cause diarrhea in volunteers) did not cause diarrhea or intestinal pathology. Intestinal colonization was transient: at 72 h postchallenge, animals inoculated with strain A-5 were culture negative, while only low numbers of strain 2076-79 were detectable (approximately 0.4 to 0.8 CFU/g). Our data highlight the utility of the RITARD model, when combined with appropriate pathologic and bacteriologic studies, for obtaining insights into pathophysiologic mechanisms of enteric disease by non-O1 V. cholerae. In agreement with volunteer studies, non-O1 V. cholerae NRT36S is clearly pathogenic in this model; direct cell invasion may play a role in its ability to cause illness.
Animals↗
Non-O1 Vibrio cholerae NRT36S produces a polysaccharide capsule that determines colony morphology, serum resistance, and virulence in mice.
Non-O1 Vibrio cholerae produced two distinct colony types, designated as opaque and translucent. NRT36S, a clinical isolate shown to be virulent in volunteers, produced predominantly opaque colonies, but translucent colonies appeared on subculture. Opaque variants were recovered exclusively following exposure to normal human serum or animal passage. A nonreverting translucent mutant of NRT36S, JVB52, was isolated following mutagenesis with the transposon Tn5 IS50L::phoA (TnphoA). Only translucent colonies were produced by a nonpathogenic environmental isolate, A5. Electron microscopic examination of the opaque form of NRT36S revealed thick, electron-dense, fibrous capsules surrounding polycationic ferritin-stained cells. The ferritin-stained material around translucent NRT36S or A5 was patchy or absent. JVB52 had a thin but contiguous capsular layer. The amount of ferritin-stained capsular material correlated with the amount of surface polysaccharide determined by phenol-sulfuric acid assay: opaque NRT36S had approximately three times as much polysaccharide as translucent NRT36S or A5 and four times as much as JVB52. The encapsulated, opaque variant of NRT36S was protected from serum bactericidal activity, while translucent non-O1 V. cholerae was readily killed. The encapsulated form also had increased virulence in mice. Our data provide the first indication that non-O1 V. cholerae strains can have a polysaccharide capsule. This capsule may be important in protecting the organism from host defenses and may contribute to the ability of some non-O1 V. cholerae strains to cause septicemia in susceptible hosts.
Animals↗
Purification and determination of the structure of capsular polysaccharide of Vibrio vulnificus M06-24.
Virulence of Vibrio vulnificus has been strongly associated with encapsulation and an opaque colony morphology. Capsular polysaccharide was purified from a whole-cell, phosphate-buffered saline-extracted preparation of the opaque, virulent phase of V. vulnificus M06-24 (M06-24/O) by dialysis, centrifugation, enzymatic digestion, and phenol-chloroform extraction. Nuclear magnetic resonance spectroscopic analysis of the purified polysaccharide showed that the polymer was composed of a repeating structure with four sugar residues per repeating subunit: three residues of 2-acetamido-2,6-dideoxyhexopyranose in the alpha-gluco configuration (QuiNAc) and an additional residue of 2-acetamido hexouronate in the alpha-galactopyranose configuration (GalNAcA). The complete carbohydrate structure of the polysaccharide was determined by heteronuclear nuclear magnetic resonance spectroscopy and by high-performance anion-exchange chromatography. The 1H and 13C nuclear magnetic resonance spectra were completely assigned, and vicinal coupling relationships were used to establish the stereochemistry of each sugar residue, its anomeric configuration, and the positions of the glycosidic linkages. The complete structure is: [----3) QuipNAc alpha-(1----3)-GalpNAcA alpha-(1----3)-QuipNAc alpha-(1----]n QuipNAc alpha-(1----4)-increases The polysaccharide was produced by a translucent phase variant of M06-24 (M06-24/T) but not by a translucent, acapsular transposon mutant (CVD752). Antibodies to the polysaccharide were demonstrable in serum from rabbits inoculated with M06-24/O.
Antigens, Bacterial↗
Changing clonal patterns of Salmonella enteritidis in Maryland: evaluation of strains isolated between 1985 and 1990.
We examined isolates from 203 sporadic and outbreak-associated Salmonella enteritidis cases occurring in Maryland between 1985 and 1990. Plasmid profiles were determined for all isolates; 52 isolates were phage typed. Ten plasmid profiles were identified. A single profile (consisting of a single ca. 55-kb plasmid) emerged as the predominant profile in Maryland during the study period. This profile (which was closely associated with phage type 8) accounted for 86% of a group of isolates from sporadic cases in 1988 and 1989, compared with 43% of the 1985 isolates. Strains with this profile were identified in four of nine outbreaks, including one of three outbreaks in which eggs were implicated as a vehicle. While plasmid profiles and phage typing appear to provide complementary means of identifying specific strains of S. enteritidis, the emergence of what appears to be a single predominant clone has reduced the discriminant ability of both typing systems. The factors be a single predominant clone has reduced the discriminant ability of both typing systems. The factors contributing to the emergence of this one clone are still not well understood.
Bacteriophage Typing↗
Development and testing of a nonradioactive DNA oligonucleotide probe that is specific for Vibrio cholerae cholera toxin.
An alkaline phosphatase-labeled oligonucleotide DNA probe (CTAP) that was specific for the cholera toxin gene (ctxA) was identified. All cholera toxin-producing strains of Vibrio cholerae, regardless of serotype, hybridized with the CTAP probe, while nontoxigenic strains from either environmental sources or from deletion or substitution mutations did not hybridize. Unlike the whole-gene probes for either ctxA or for the heat-labile toxin or Escherichia coli (eltA), this 23-base sequence did not hybridize with E. coli or with vibrios other than V. cholerae that produce related toxins. By using CTAP to identify colonies grown on nonselective medium, V. cholerae was enumerated at concentrations of 10(3) to 10(7)/g from stool samples of volunteers who had ingested V. cholerae O1 strain 569B. CTAP provides a specific and sensitive tool for diagnosis and environmental monitoring of cholera toxin-producing V. cholerae.
Base Sequence↗
Delayed radiation necrosis of the central nervous system in patients irradiated for pituitary tumours.
Four cases of delayed radiation necrosis involving the CNS were found in a group of 46 patients irradiated for pituitary tumours over a six year period. This occurred in three of 11 patients with Cushing's disease representing an incidence of 27% in this group. There were no cases among 11 patients with acromegaly or among seven with prolactinomas. One case (6%) was found in the 17 patients with chromophobe adenomas. Standard doses of radiation were delivered to these patients and the findings support suggestions that the metabolic disturbances of Cushing's disease may reduce tolerance to radiation. Our results and a literature review indicate that if radiotherapy is used to treat Cushing's disease, the total dose should be less than 50 Gy at 2 Gy per day fractionation.
Adenoma↗