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Chemical characterization of the regularly arranged surface layers of Clostridium thermosaccharolyticum and Clostridium thermohydrosulfuricum.

Clostridum thermosaccharolyticum and Clostridium thermohydrosulfuricum possess as outermost cell wall layer a tetragonal or hexagonal ordered array of macromolecules. The subunits of the surface layer can be detached from isolated cell walls with urea (8M) or guanidine-HCl (4 to 5 M). Triton X-100, dithiothreitol, ethylenediaminetetracetate, and KCl (3 M) had no visible effect on the regular arrays. Sodium dodecyl sulfate-polyacrylamide electrophroesis showed that, in both organisms, the surface layer is composed of glycoprotein of molecular weight 140,000. The glycoprotein from both microorganisms has a predominantly acidic amino acid composition and an acidic isoelectric point after isoelectric focusing on polyacrylamide gels. The glycocomponent is composed of glucose, galactose, mannose, and rhamnose.

Amino Acids↗

Ferredoxin and formyltetrahydrofolate synthetase: comparative studies with Clostridium acidiurici, Clostridium cylindrosporum, and newly isolated anaerobic uric acid-fermenting strains.

Six strains of Clostridium acidiurici and three strains of C. cylindrosporum were isolated from soil samples by enrichment culture with uric acid as the source of carbon, nitrogen, and energy. The newly isolated strains were characterized by their spore morphology and the amounts of glycine and formate formed by the fermentation of uric acid. The strains were easily identified as belonging to one species or the other on the basis of spore morphology and formate production. The crystal properties and spectra of the native ferredoxins of all the strains isolated and the amino acid composition and partial carboxy-terminal sequence of all their apoferredoxins were determined. All the ferredoxins were tested for cross-reactivity with antiserum to C. acidiurici ferredoxin by microcomplement fixation. Five of the six C. acidiurici strains, which had ferredoxins with amino acid compositions identical to that from C. acidiurici, also showed immunological identity (immunological distance = 0.0). These results suggest sequence identity. The one strain with a different amino acid composition failed to show complete cross-reactivity. Two of the three C. cylindrosporum strains have ferredoxin amino acid compositions identical to that from C. cylindrosporum. The third strain had a minimum of five differences in sequence. All C. cylindrosporum strains had ferredoxins that differed considerably from C. acidiurici strains (minimum of eight to nine differences), and none of these ferredoxins cross-reacted with antisera to C. acidiurici ferredoxin. Antisera were prepared to formyltetrahydrofolate synthetase from C. acidiurici and C. cylindrosporum, and all possible comparisons were made by using immunodiffusion and microcomplement fixation. There is more intraspecies variation in the synthetases than in the ferredoxins; however, the results suggest considerable interspecies differences in both proteins. These results suggest a low degree of genomic relatedness between the two species, which contrasts sharply with their apparent high degree of phenotypic similarity.

Amino Acid Sequence↗

Carbon monoxide oxidation by Clostridium thermoaceticum and Clostridium formicoaceticum.

Cultures of Clostridium formicoaceticum and C. thermoaceticum growing on fructose and glucose, respectively, were shown to rapidly oxidize CO to CO(2). Rates up to 0.4 mumol min(-1) mg of wet cells(-1) were observed. Carbon monoxide oxidation by cell suspensions was found (i) to be dependent on pyruvate, (ii) to be inhibited by alkyl halides and arsenate, and (iii) to stimulate CO(2) reduction to acetate. Cell extracts catalyzed the oxidation of carbon monoxide with methyl viologen at specific rates up to 10 mumol min(-1) mg of protein(-1) (35 degrees C, pH 7.2). Nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate and ferredoxin from C. pasteurianum were ineffective as electron acceptors. The catalytic mechanism of carbon monoxide oxidation was "ping-pong," indicating that the enzyme catalyzing carbon monoxide oxidation can be present in an oxidized and a reduced form. The oxidized form was shown to react reversibly with cyanide, and the reduced form was shown to react reversibly with alkyl halides: cyanide inactivated the enzyme only in the absence of carbon monoxide, and alkyl halides inactivated it only in the presence of carbon monoxide. Extracts inactivated by alkyl halides were reactivated by photolysis. The findings are interpreted to indicate that carbon monoxide oxidation in the two bacteria is catalyzed by a corrinoid enzyme and that in vivo the reaction is coupled with the reduction of CO(2) to acetate. Cultures of C. acidi-urici and C. cylindrosporum growing on hypoxanthine were found not to oxidize CO, indicating that clostridia mediating a corrinoid-independent total synthesis of acetate from CO(2) do not possess a CO-oxidizing system.

Acetates↗

Quantities of Clostridium botulinum organisms and toxin in feces and presence of Clostridium botulinum toxin in the serum of an infant with botulism.

A 7-week-old boy presented with symptoms and signs characteristic of infant botulism, and the diagnosis was confirmed by the detection of Clostridium botulinum type A organisms and toxin in the feces. The levels of organisms and toxin in the feces were measured throughout the 81-day period in hospital. The maximum levels detected were 2.46 x 10(8) C. botulinum type A colony-forming units and 64,000 mouse 100% lethal doses of type A toxin per g (wet weight) of feces. C. botulinum toxin was also detected in two samples of the patient's serum, collected 3 and 10 days after admission. Improvement in the patient's clinical condition occurred before the levels of organisms and toxin in the feces reached their maxima. A slight improvement may also have occurred while toxin was still present in the serum.

Botulinum Toxins↗

Isolation and enumeration of Clostridium botulinum by direct inoculation of infant fecal specimens on egg yolk agar and Clostridium botulinum isolation media.

Direct plating of stool specimens on selective (Clostridium botulinum isolation) and nonselective (egg yolk agar) media was evaluated as an aid in confirming infant botulism. C. botulinum was isolated from 13 of 14 culture-positive specimens with C. botulinum isolation and from 8 of 14 egg yolk agar. No lipase reaction was seen on plates of 31 culture-negative specimens.

Agar↗

Genetic confirmation of identities of neurotoxigenic Clostridium baratii and Clostridium butyricum implicated as agents of infant botulism.

Two unusual neurotoxigenic clostridia isolated from fecal specimens from patients with type F and type E infant botulism were phenotypically identical to the existing species Clostridium baratii and C. butyricum, respectively. DNA hybridization experiments confirmed that one strain was C. baratii and that the other was C. butyricum. These species therefore do contain neurotoxigenic strains and are possible causes of infant botulism.

Botulism↗

Characterization of a toxin A-negative, toxin B-positive strain of Clostridium difficile responsible for a nosocomial outbreak of Clostridium difficile-associated diarrhea.

Clostridium difficile-associated diarrhea (CAD) is a very common nosocomial infection that contributes significantly to patient morbidity and mortality as well as to the cost of hospitalization. Previously, strains of toxin A-negative, toxin B-positive C. difficile were not thought to be associated with clinically significant disease. This study reports the characterization of a toxin A-negative, toxin B-positive strain of C. difficile that was responsible for a recently described nosocomial outbreak of CAD. Analysis of the seven patient isolates from the outbreak by pulsed-field gel electrophoresis indicated that this outbreak was due to transmission of a single strain of C. difficile. Our characterization of this strain (HSC98) has demonstrated that the toxin A gene lacks 1.8 kb from the carboxy repetitive oligopeptide (CROP) region but apparently has no other major deletions from other regions of the toxin A or toxin B gene. The remaining 1.3-kb fragment of the toxin A CROP region from strain HSC98 showed 98% sequence homology with strain 1470, previously reported by M. Weidmann in 1997 (GenBank accession number Y12616), suggesting that HSC98 is toxinotype VIII. The HSC98 strain infecting patients involved in this outbreak produced the full spectrum of clinical illness usually associated with C. difficile-associated disease. This pathogenic spectrum was manifest despite the inability of this strain to alter tight junctions as determined by using in vitro tissue culture testing, which suggested that no functional toxin A was produced by this strain.

Adolescent↗

Acquisition of Clostridium difficile and Clostridium difficile-associated diarrhea in hospitalized patients receiving tube feeding.

BACKGROUND: Clostridium difficile is the most common infectious cause of nosocomial diarrhea, but its role in diarrhea associated with tube feeding has not been rigorously investigated. OBJECTIVE: To determine the incidence of C. difficile acquisition and C. difficile-associated diarrhea in tube-fed and non-tube-fed patients. DESIGN: Prospective cohort study. SETTING: A university-affiliated Veterans Affairs Medical Center. PATIENTS: 76 consecutive hospitalized, tube-fed patients and 76 hospitalized, non-tube-fed patients. The two cohorts were matched for age, unit location, duration of hospitalization before surveillance, and severity of illness. MEASUREMENTS: Incidence of C. difficile acquisition, incidence of C. difficile-associated diarrhea, and C. difficile restriction endonuclease analysis typing results. RESULTS: More tube-fed patients than non-tube-fed patients acquired C. difficile (15 of 76 patients [20%] compared with 6 of 76 patients [8%]; P=0.03) and developed C. difficile-associated diarrhea (7 of 76 patients [9%] compared with 1 of 76 patients [1%]; P=0.03). The mean proportion (+/-SD) of surveillance days with diarrhea was greater for tube-fed patients after the development of C. difficile-associated diarrhea than for tube-fed patients without this diarrhea (0.68+/-0.4 compared with 0.22+/-0.2 [95% CI for the mean difference, 0.08 to 0.84]). Postpyloric tube feeding (odds ratio, 3.14 [CI, 1.008 to 9.77]) and duration of surveillance (odds ratio, 1.08 [CI, 1.0009 to 1.16]) were risk factors for the acquisition of C. difficile. Nineteen restriction endonuclease analysis types of C. difficile were identified from 20 patients. CONCLUSIONS: Hospitalized, tube-fed patients, especially those receiving postpyloric tube feeding, are at greater risk for the acquisition of C. difficile and the development of C. difficile-associated diarrhea than are hospitalized, non-tube-fed patients. Clinicians should test for C. difficile in tube-fed patients with diarrhea.

Aged↗

The roles of Clostridium difficile and enterotoxigenic Clostridium perfringens in diarrhea in dogs.

In this prospective study, feces of dogs with diarrhea were compared with feces of normal dogs for the presence of Clostridium difficile, C difficile toxins A and B, C perfringens, and C perfingens enterotoxin (CPE). C difficile toxins A, B, or both were present in feces of 18 of 87 (21%) dogs with diarrhea and 4 of 55 (7%) normal dogs (P = 0.03), whereas CPE was present in the feces of 24 of 87 (28%) dogs with diarrhea and 3 of 55 (5%) normal dogs (P = 0.01). C difficile was isolated from 2 of 87 (2%) dogs with diarrhea but was not isolated from the feces of 55 normal dogs, possibly because of poor survival of the organism in fecal samples. C perfringens was isolated from the feces of 23 of 24 (96%) CPE-positive dogs with diarrhea, 52 of 63 (83%) CPE-negative dogs with diarrhea, and 39 of 55 (71%) CPE-negative dogs with normal feces. No correlation was found between C perfringens spore number and the presence of CPE.

Animals↗

Studies on the cultivation of Clostridium oncolyticum M 55. 5th communication: The influence of iron, zinc, and cobaltous ions on the growth and the kininase activity of clostridium oncolyticum M 55 ATCC 13.732.

The precipitation or iron sulfide by hydrogen sulfide excreting Clostridium oncolyticum M 55 led to further examinations in order to avoid this disturbing factor. The method should render the cultivation of Cl. oncolyticum M 55 under definite conditions and should also intensify the formation and the enrichment of the clostridial kininases. Cobaltous ions and zinc granules were found useful for cultivation, because no disturbances increased from both during sterilization and incubation. The determination of the growth cycles and the replication rates showed the usefulness of zinc for substitution of iron. Cobaltous ions did only allow a low replication rate. These results confirmed those showing the influence of chelate-forming agents on the kininase activity. Cobaltous ions were not able to exchange the central atom of the metallo-proteide. The influence of the peptone quality on the kininase activity in presence of zinc was also examined, since examinations with iron media have shown a direct connection between peptone quality and enzyme activity. The results with zinc-containing media were nearly 5-10% lower than those with iron. The results allowed also the conclusion that the kininase excreted by Cl. oncolyticum M 55 is an iron-containing metallo-proteide, whose central atom is exchangeable for zinc. The consequences of the loss of enzyme activity for the oncolytic therapy with Cl. oncolyticum M 55 will be shown in further examinations.

Acetates↗

[Incidence of Clostridium botulinum in the rumen contents and faeces of cattle fed brewers' grains naturally contaminated with Clostridium botulinum (author's transl)].

The number of Clostridium botulinum type B organisms excreted by cattle fed brewers' grains in which these organisms were found to be present and the period for which they were excreted, were studied. Large numbers (10(5) - 10(7) per gramme) of these organisms were detected in the rumen contents and faeces of the animals. When feeding brewers' grains was discontinued, Cl. botulinum type B was still detectable in the faeces for a considerable period (greater than eight weeks). There was evidence to suggest that the number of Cl. botulinum organisms multiplies in the gastrointestinal tract of cattle.

Animal Feed↗

[Glucose metabolism in Clostridium sporogenes and Clostridium sticklandii bacteria].

Clostridium sporogenes 272 has a high rate of glucose fermentation. Its cell-free extract contains all glycolytic enzymes catalysing glucose degradation to pyruvate and shows the phosphoroclastic activity. C. sticklandii CSG has a low rate of glucose fermentation. Hence, the activity of the following enzymes is lower in this organism comparing to C. sporogenes: phosphohexoisomerase (EC 5.3.1.9), phosphofructokinase (EC 2.7.1.11), aldolase (EC 4.1.2.13), triosephosphate isomerase (EC 5.3.1.1) and glyceraldehyde phosphate dehydrogenase (EC 1.2.1.12). Moreover, it is possible that the system of glucose transport into the cell is damaged in C. sticklandii.

Clostridium↗