Acta Pathol Microbiol Scand {B}, 1981 Oct, 89(5), 363 - 7 Enzymatic hydrolysis by bacterial phospolipases C and D of immobilized radioactive sphingomyelin and phosphatidylcholine; Malmqvist T et al.; An assay system for phospholipases C has been described with sphingomyelin immobilized to octyl-Sepharose CL-4B as substrate . The immobilization procedure was further developed and used with {14 C-choline}-sphingomyelin and {14C-choline} phosphatidylcholine (lecithin) . These immobilized radioactive phospholipids made the enzymatic assays easier to perform and made it possible to increase the sensitivity . Furthermore, since release of the choline part instead of the phosphate part of the substrate molecule was measured, it was possible to use this assay for phospholipase D as well . The enzyme characteristics of phospholipase D from Corynebacterium ovis were compared in this test system with those of three phospholipases C (from Clostridium perfringens, Bacillus cereus and Staphylococcus aureus) with respect to hydrolysing capacities and optimal ion concentrations. Acta Pathol Microbiol Scand {B}, 1981 Oct, 89(5), 357 - 61 Enzymatic hydrolysis of immobilized sphingomyelin by three bacterial phospholipases C; Malmqvist T et al.; Through hydrophobic interaction, sphingomyelin was adsorbed to agarose beads containing octyl groups by a stepwise dilution procedure . This immobilized lipid was used as a substrate for three bacterial phospholipases C (E.C . 3.1.4.3.) . The degradation with time of this substrate showed two different fractions of the substrate according to hydrolysing velocity in the early part of the time-curve when phospholipases C from Bacillus cereus and Clostridium perfringens were used . The early fractions could be predigested by the enzymes, a procedure which resulted in linear time-curves . The corresponding early part of the time-curve for phospholipase C from Staphylococcus aureus was linear, indicating a comparatively large early fraction of the substrate for this enzyme . The stock gel of the immobilized lipid substrate could be stored for months . It was easily and reproducibly handled as a water suspension . After enzymatic hydrolysis the substrate was rapidly separated from enzyme and product by filtration . The enzyme assay presented thus represents a convenient way to avoid the difficulties connected with the use of temporary sonicated suspensions as substrate for bacterial phospholipases C. Infect Immun, 1981 Oct, 34(1), 50 - 4 Stimulation of Clostridium perfringens enterotoxin formation by caffeine and theobromine; Labbe RG et al.; In the presence of 100 micrograms of caffeine per ml or 200 micrograms of theobromine per ml, sporulation of Clostridium perfringens NCTC 8679 rose from less than 1 to 80 or 85% . Enterotoxin concentration increased from undetectable levels to 450 micrograms/mg of cell extract protein . Heat-resistant spore levels increased from less than 1,000 to between 1 X 10(7) and 2 X 10(7)/ml . These effects were partially reversible by the addition of adenosine or thymidine . In the case of NCTC 8238, caffeine and theobromine caused a three- to fourfold increase in the percentages of cells possessing refractile spores and a similar increase in enterotoxin concentration . Heat-resistant spore levels, however, were unaffected . Inosine was ineffective in promoting sporulation in NCTC 8679. Antimicrob Agents Chemother, 1981 Oct, 20(4), 437 - 42 Inhibition of ribonucleic acid polymerase by a bacteriocin from Bacteroides fragilis; Mossie KG et al.; The Bacteroides fragilis bacteriocin which inhibits ribonucleic acid (RNA) polymerase activity had a narrow activity spectrum in vivo and only inhibited the growth of certain B . fragilis strains . In vitro the bacteriocin was not specific and inhibited RNA polymerases from widely diverse bacterial genera . RNA polymerases from rifampin-resistant strains of Bacteroides thetaiotaomicron and Clostridium acetobutylicum were resistant to the bacteriocin in vitro . Purified bacteriocin bound to partially purified RNA polymerase, and both proteins were cosedimented in a glycerol gradient . In the RNA polymerase reaction, the bacteriocin acted as a competitive inhibitor for adenosine, cytidine, and uridine 5'-triphosphates and as a noncompetitive inhibitor for guanosine 5'-triphosphate . The bacteriocin did not inhibit RNA polymerase from chicken embryos. Am J Gastroenterol, 1981 Oct, 76(4), 374 - 6 Pseudomembranous colitis . A complication of sulfasalazine therapy in a patient with Crohn's colitis; Pokorney BH et al.; Pseudomembranous colitis is a potentially life-threatening acute medical problem usually associated with a history of previous antibiotic exposure . Presented here is a case of sulfasalazine associated pseudomembranous colitis in a patient with known Crohn's colitis . The diagnosis was confirmed by identifying Clostridium difficile toxin in the stool . This a newly reported complication of sulfasalazine therapy. Biochim Biophys Acta, 1981 Sep 4, 676(3), 395 - 400 Role of phosphatidylinositol in basal adenylate cyclase activity of rat heart sarcolemma; Panagia V et al.; The adenylate cyclase activity and phospholipid composition were determined in rat heart sarcolemma after treating the membranes with a phosphatidylinositol-specific phospholipase C . Complete hydrolysis of phosphatidylinositol in sarcolemma was associated with a marked loss of the basal adenylate cyclase activity . The recombination of the supernatant with the phosphatidylinositol-depleted membranes was found to reactivate the adenylate cyclase activity . The soluble component(s) in the supernatant, which restored the adenylate cyclase activity, was thermolabile and precipitated by ammonium sulfate . Extensive hydrolysis of phosphatidylcholine, phosphatidylethanolamine and sphingomyelin in sarcolemma with a Clostridium welchii phospholipase C treatment did not affect the basal adenylate cyclase activity . These results suggest that phosphatidylinositol anchors component(s) essential for the expression of basal adenylate cyclase activity to the myocardial cell membrane. Biochemistry, 1981 Sep 1, 20(18), 5124 - 31 Transient kinetics of electron-transfer reactions of flavodoxins; Jung J et al.; Stopped-flow and laser photolysis methods have been used to investigate the rates of electron-transfer reactions of fully reduced riboflavin and the three oxidation states of Clostridium pasteurianum flavodoxin . Both normal and 7,8-dichloroflavin analogues were studied . Redox reagents included oxygen, ferricyanide, ferric EDTA, and several c-type cytochromes as oxidants and the semiquinone of 5-deazariboflavin as a reductant . The dependence of the rate of oxidation of the semiquinone form of the dichloro analogue flavodoxin upon oxidant concentration has provided clear evidence for the existence of a complex in the reaction pathway . Rate constant comparisons demonstrate that dichloro substitution decreases the rate of flavodoxin semiquinone oxidation by at least 1-2 orders of magnitude . The limiting first-order rate constants were found to be dependent on the redox potential of the oxidant, as would be predicted by theory if these were reflecting the actual electron-transfer reaction . Rate constant decreases upon chlorine substitution were also observed for the reduction of both oxidized and semiquinone forms of flavodoxin by deazariboflavin semiquinone . These results, considered in conjunction with the redox potential shift of the flavodoxin produced by the chlorine substitution, provide support for the hypothesis that electron transfer to and from the semiquinone form of the flavodoxin involves direct participation of the dimethylbenzene ring of the flavin . A comparison of oxidation rate constants for free and protein-bound fully reduced flavin suggests that the protein environment does not markedly influence coenzyme reactivity in this oxidation state. Klin Padiatr, 1981 Sep, 193(5), 398 - 400 {Haemolysis as initial sign of Clostridium perfringens septicaemia in newborn (author's transl)}; Tollner U et al.; Cases of Clostridium perfringens, septicaemia are subject to a very gloomy prognosis in adults . This applies likewise to the rare cases reported in paediatric literature . The present report describes the fatal case of a newborn with Clostridium perfringens septicaemia . The principal sign was a severe haemolysis which failed to respond to blood exchange transfusions and antibiotic treatment . The characteristic changes of colour of the skin usually observed in septicaemia of newborn had probably been masked for some time by the reddish discolouration caused by the haemolysis, so that diagnosis was established at a late stage only. Can J Surg, 1981 Sep, 24(5), 453 - 5 Necrotizing anaerobic infections; Bocking JK et al.; Severe necrotizing anaerobic infections carry a high mortality . From a retrospective review of 17 cases of gas gangrene, necrotizing fasciitis and nonclostridial myonecrosis seen at the Victoria and University hospitals in London, Ontario, between Jan . 1, 1975 and Dec . 31, 1977, the most common antecedent was found to be minor trauma . Location of the infection varied; the scrotum and perineum were most commonly involved . Local findings were most frequently edema, skin tenderness and induration . Mixed infections predominated with a pure growth of Clostridium sp . occurring in only three cases . The overall mortality was 29% . The mainstay of treatment after initial administration of fluids followed by broad-spectrum antibiotics is early aggressive surgical debridement of all necrotic tissue. Am J Dis Child, 1981 Sep, 135(9), 820 - 2 Clostridium difficile associated with pseudomembranous colitis . Occurrence in a 12-week-old infant without prior antibiotic therapy; Adler SP et al.; In a previously healthy 12-week-old male infant with a two-week history of poor feeding, colic, and bloody stools, pseudomembranous colitis developed . No prior antibiotics were administered although the child had received dicyclomine hydrochloride . Clostridium difficile and its toxin were detected in the child's stool . Severe disseminated intravascular coagulopathy developed; the patient required total colectomy but eventually recovered . Clostridium difficile colonization has not, to our knowledge, been previously documented in infantile pseudomembranous colitis. J Can Assoc Radiol, 1981 Sep, 32(3), 149 - 52 Pseudomembranous colitis in renal transplant recipients; plain film findings; Hutton L et al.; The plain abdominal film findings in nine renal transplant patients with pseudomembranous colitis were characteristic of but not specific for this entity and most commonly showed "thumb-printing" reflecting submucosal edema (five patients) and a persisting localized segmental ileus in the colon (five patients) . Based on the plain film findings, the differential diagnosis will include the acute stages of ulcerative colitis, granulomatous colitis, ischemic colitis and other inflammatory colitides, but the radiologist is in a position to suggest the correct diagnosis in the appropriate clinical setting . A barium study of the colon is not indicated, as diagnosis is usually accomplished by endoscopy . The etiology of this colitis has recently been shown to be a cytopathic toxin of the anaerobic bacterium, Clostridium difficile. Can J Microbiol, 1981 Sep, 27(9), 942 - 8 Purification and partial characterization of proline dehydrogenase from Clostridium sporogenes; Monticello DJ et al.; A proline dehydrogenase which catalyzes the nicotinamide adenine dinucleotide (NAD) dependent oxidation of proline and the NADH-dependent reduction of delta 1-pyrroline 5-carboxylic acid (PCA) was purified from extracts of Clostridium sporogenes . Following purification, only one protein band was found on analytical polyacrylamide disc gels and on sodium dodecyl sulfate (SDS) - polyacrylamide disc gels . Sucrose density gradient centrifugation and SDS-gel electrophoresis indicated that the enzyme has a molecular weight of approximately 217 000 and consists of two subunits of equal size . During purification of proline dehydrogenase on hydroxylapatite the ratio of dehydrogenase activity to reductase activity decreases significantly, and a similar change in ratio was brought about by storage of partially purified enzyme preparations in low ionic strength buffers . Subsequent purification did not change the ratio . The dehydrogenase activity of proline dehydrogenase was inhibited by L-glutamate (Ki = 0.32 mM at pH 7.4 and Ki = 0.65 mM at ph 10.2) . However, the reductase activity of the purified enzyme was not affected by 100 mM L-glutamate. Zh Mikrobiol Epidemiol Immunobiol, 1981 Sep, (9), 57 - 62 {Immunochemical study of Clostridium botulinum type B toxin}; Kliucheva VV et al.; Fractionation of type B . Cl . botulinum toxin, a protein complex, was carried out; as a result, 3 fractions, alpha, beta, and gamma, were isolated in a pure form, alpha-fraction, or neurotoxin, is highly toxic (5-10.10(7) LDm per 1 mg of protein), beta-fraction showed hemagglutinating activity (64-128 HAU per 1 mg of protein), gamma-fraction was not biologically active . The molecular weight of alpha and gamma-fractions was 150,000 . All these fractions had antigenic properties . alpha-fraction was serologically specific . beta- and gamma-fractions showed incomplete serologic identity. Appl Environ Microbiol, 1981 Sep, 42(3), 477 - 83 Mechanisms of sorbate inhibition of Bacillus cereus T and Clostridium botulinum 62A spore germination; Smoot LA et al.; The mechanism by which potassium sorbate inhibits Bacillus cereus T and Clostridium botulinum 62A spore germination was investigated . Spores of B . cereus T were germinated at 35 degrees C in 0.08 M sodium-potassium phosphate buffers (pH 5.7 and 6.7) containing various germinants (L-alanine, L-alpha-NH2-n-butyric acid, and inosine) and potassium sorbate . Spores of C . botulinum 62A were germinated in the same buffers but with 10 mM L-lactic acid, 20 mM sodium bicarbonate, L-alanine or L-cysteine, and potassium sorbate . Spore germination was monitored by optical density measurements at 600 nm and phase-contrast microscopy . Inhibition of B . cereus T spore germination was observed when 3,900 micrograms of potassium sorbate per ml was added at various time intervals during the first 2 min of spore exposure to the pH 5.7 germination medium . C . botulinum 62A spore germination was inhibited when 5,200 micrograms of potassium sorbate per ml was added during the first 30 min of spore exposure to the pH 5.7 medium . Potassium sorbate inhibition of germination was reversible for both B . cereus T and C . botulinum 62A spores . Potassium sorbate inhibition of B . cereus T spore germination induced by L-alanine and L-alpha-NH2-n-butyric acid was shown to be competitive in nature . Potassium sorbate was also a competitive inhibitor of L-alanine- and L-cysteine-induced germination of C . botulinum 62A spores. J Gen Microbiol, 1981 Sep, 126(Pt 1), 37 - 44 Extraction of spore-lytic enzyme from Clostridium perfringens spores; Gombas DE et al.; Various chemical reagents known to extract spore coat protein were used to extract spore-lytic enzyme (SLE) from intact and germinated spores of Clostridium perfringens . Of the reagents tested, 7.2 M-urea plus 10% (v/v) mercaptoethanol, pH 2.85, solubilized the most SLE activity per mg spores . The quantity of SLE extracted was dependent on the initial pH of the reagent, with a maximum between pH 2.7 and 3.0 . Germinated spores yielded more SLE than non-germinated spores upon urea/mercaptoethanol extraction . SLE release during spore germination probably utilizes a trigger mechanism not satisfied by germination alone . Significant amounts of SLE were released during germination when spores were suspended in potassium chloride or a complex germinant mixture containing brain-heart infusion, yeast extract and chloramphenicol, but not during germination with sodium nitrite, which non-enzymically lysed the cortical peptidoglycan . Greater solubilization of SLE activity was obtained by urea/mercaptoethanol extraction of spores germinated with nitrite than of spores germinated with either potassium chloride or the complex germinant. Biull Eksp Biol Med, 1981 Sep, 92(9), 322 - 5 {Factors modulating production of antibodies against Clostridium perfringens in mammals}; Shemanova GF et al.; Immunogenic properties of Clostridium perfringens type A toxoid preparations obtained by different methods are described . As regards immunogenicity for guinea-pigs and man, toxoid obtained by the detoxification of preliminarily purified alpha-toxin (experimental toxoid) compares favourably with preparations obtained by the detoxification of alpha-toxin in a culture fluid . It was shown in experiments on guinea pigs that immunogenicity of experimental toxoid rises with the increase in the degree of purification of alpha-toxin used for detoxification . The least purified preparations turned out to be the most immunogenic for mice . In Cl . perfringens culture fluid, factor (factors) was found and separated, which reduced the immunogenicity of the respective toxoid in experiments with immunization of guinea pigs and increased it in mice . Activation of antibody-formation was disclosed to be nonspecific . The existence of this factor(s) should be taken into account in the development of vaccines and methods for evaluating their immunogenic properties. Appl Environ Microbiol, 1981 Sep, 42(3), 394 - 9 Transformation of bile acids by Clostridium perfringens; Hirano S et al.; Thirty-five strains of Clostridium perfringens were examined for their ability to transform bile acids, both in growing cultures and by washed whole cells . All of the strains oxidized the 3 alpha-hydroxy group to an oxo group, and all except three converted the same alpha-hydroxy group into a beta-configuration . The oxidative 3 alpha-dehydrogenation was barely detectable under anaerobic cultural conditions but was clearly demonstrated in an aerated system using washed whole cells, with a pH optimum between 7.0 and 9.0 . The epimerizing reaction amounting to 10 to 20% conversion was observed in anaerobic cultures and also with resting cells, irrespective of oxygen supply . Both reactions were carried out with seven conventional 3 alpha-hydroxy bile acids, thus producing a series of 3-oxo and 3 beta-hydroxy derivatives that could be examined for gas-liquid chromatographic and mass spectrometric behavior . No evidence for the occurrence of 7 alpha- and 12 alpha-hydroxysteroid dehydrogenase activities among the test strains was found . A highly potent deconjugating hydrolase was elaborated by all of the strains. Arch Inst Pasteur Tunis, 1981 Sep-Dec, 58(3), 355 - 73 {Thiol-dependent cytolytic bacterial toxins: streptolysin O and prominent toxins}; Alouf JE; Streptolysin O is the prototype of fifteen bacterial cytolytic protein toxins elaborated by gram-positive bacteria of species Streptococcus, Clostridium, Bacillus and Listeria . These toxins share a number of common properties: they are antigenically related as shown by cross-neutralization and immunoprecipitation; their cytolytic and other reducing agents; these toxins are inactivated by cholesterol and certain related sterols . This group of oxygen-labile cytolytic toxins has been named sulfyhdryl-activated toxins or thiol-activated cytolysins . The mechanism of action of these toxins is very likely identical or at least closely similar. Biochim Biophys Acta, 1981 Aug 24, 665(2), 262 - 9 Bile induction of 7 alpha- and 7 beta-hydroxysteroid dehydrogenases in Clostridium absonum; MacDonald IA et al.; Eight strains of Clostridium absonum grown in the presence of 4 . 10(-4) M deoxycholate contained both NADP-dependent 7 alpha- and 7 beta-hydroxysteroid dehydrogenase activities . In one strain studied in detail, significant amounts of NADP-dependent 7 alpha- and 7 beta-hydroxysteroid dehydrogenase and NAD-dependent 7 alpha-hydroxysteroid dehydrogenase activities were demonstrated only when cells were grown in the presence of deoxycholate or chenodeoxycholate, both optimal at 4 . 10(-4) M . When the bile salt was deleted from the medium, only a trace of 7 alpha-hydroxysteroid dehydrogenase was present and 7 beta-hydroxysteroid dehydrogenase was absent . Other bile salts including cholate, ursodeoxycholate and keto bile salts were less effective as inducers . Addition of cholate to medium already containing deoxycholate at a suboptimal concentration enhanced the induction, while addition of ursodeoxycholate suppressed the induction . Further enhancement of 7 alpha- and 7 beta-hydroxysteroid dehydrogenase could be obtained by additions of deoxycholate (up to a total of 6 . 10(-4) M) during the growth of the organisms (in log phase) . As enzyme enhancement is blocked by addition of rifampicin to the medium, the authors conclude that the enzymes are bile salt-inducible . Growth curve studies revealed an optimal enzyme yield at a harvest time of approx . 6-9 h . We have preliminarily characterized several inducible enzyme components: an NADP-dependent 7 beta-hydroxysteroid dehydrogenase as well as both NAD- and NADP-dependent 7 alpha-hydroxysteroid dehydrogenases. Biochim Biophys Acta, 1981 Aug 13, 660(2), 251 - 5 Thermostable, ammonium-activated malic enzyme of Clostridium thermocellum; Lamed R et al.; "Malic" enzyme (L-malate:NADP+ oxidoreductase (oxaloacetate-decarboxylating, EC 1.1.1.40) was purified from Clostridium thermocellum by DEAE-cellulose, agarose-NADP and Sephadex G-200 column chromatography . The 117-fold purified "malic" enzyme displayed a maximum activity of 135 units/mg at 40 degrees C and represented 0.8% of the total cell protein . Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis analysis of the protein suggested 90% purity and an approximate tetrameric subunit molecular weight of 40 000 . The enzyme absolutely required both bivalent and monovalent cations for catalysis . Mn2+ and NH4+ were the most effective cationic activators examined . Increasing NH4+ concentration increased both enzyme activity and affinity toward L-malate . The apparent Km for L-malate was 3 X 10(-4) M at 0.4 mM NH4Cl . Enzyme activity increased linearly when temperature was raised between 22-60 degrees C and a Q10 of 2.1 was calculated from an Arrhenius plot . The enzyme was stable at heating at 60 degrees C but was denatured at higher temperatures . The enzyme half-life was 10 min at 72 degrees C . The enzyme displayed a broad pH optimum (7.2-87.2 for Tris-HCl buffer) but was inactivated by p-chloromercuribenzoate . The high thermal stability, low apparent molecular weight and NH4+ activation are properties not common to all previously described "malic" enzymes. Biochem J, 1981 Aug 1, 197(2), 293 - 9 The release of N-acetyl- and N-glycolloyl-neuraminic acid from soluble complex carbohydrates and erythrocytes by bacterial, viral and mammalian sialidases; Corfield AP et al.; A series of substrates, sialyl(2 leads to 6)GalNAc and ganglioside GM3, containing either N-acetylneuraminic acid (AcNeu) or N-glycolloylneuraminic acid (GcNeu), has been prepared . The trisaccharide GcNeu(2 leads to 3)lactose was preapred by ozonolysis of GcNeu-GM3, and the disaccharides AcNeu(2 leads to 6)GalNAc and GcNeu(2 leads to 6)GalNAc were isolated from bovine submandibular-gland mucin by alkali elimination . Sialidases from Newcastle-disease virus, fowl-plague virus, influenza virus A2, Clostridium perfringens, Vibrio cholerae, Arthrobacter ureafaciens and human liver lysosomes were studied with the above substrates and all showed poorer cleavage of GcNeu-containing substrates when compared with the corresponding AcNeu-containing compounds . This was reflected in the Km and Vmax . values of these sialidases . Differences between viral and bacterial sialidases could be detected on the basis of their kinetic constants and time curves of sialic acid release . Preferred release of AcNeu relative to GcNeu was also observed with bovine submandibular gland mucin and a mixture of human and porcine erythrocytes, macromolecular substrates containing both AcNeu and GcNeu . The significance of differential cleavage of AcNeu and GcNeu by sialidases is considered together with examples of the role of GcNeu in physiologicaL systems. Can J Microbiol, 1981 Aug, 27(8), 824 - 34 Stable isotope fractionation by Clostridium pasteurianum . 4 . Sulfur isotope fractionation during enzymatic S3O6(2-), S2O3(2-), and SO3(2-) reductions; Harrison GI et al.; Cell-free extracts from Clostridium pasteurianum grown on SO3(2-) utilize H2 to reduce S3O6(2-), S2O3(2-), SO3(2-) to H2S at a much faster rate than extracts from SO4(2-)-grown cells . This further supports the concept of an inducible dissimilatory type SO3(2-) reductive pathway in this organism . 35S dilution experiments further support the concept that S3O6(2-) and S2O3(2-) are pathway intermediates . The inducible SO3(2-) reductase is ferredoxin linked and the kinetics of the reduction and the sulfur isotope fractionation of the product can be altered by altering the growth conditions . The attending sulfur isotope fractionations are similar to those observed during the chemical decomposition of these compounds . In the case of S2O3(2-), 35S labelling experiments verified the conclusions derived from the stable isotope fractionation data concerning the relative reduction rates of the sulfane and sulfonate sulfurs . The reduction rates were also affected by enzyme concentration . The integrity of the whole cell is a necessary requirement for the large inverse isotope effects previously reported. Br J Surg, 1981 Aug, 68(8), 560 - 4 The microflora of the postoperative stomach; Muscroft TJ et al.; The microflora and pH have been assessed in gastric aspirates from 163 patients after gastric surgery and have been compared with 51 patients with gastro-oesophageal carcinoma, 152 unoperated patients with peptic ulceration, 72 of whom were receiving cimetidine, 3 patients with pernicious anaemia and 27 normal subjects . The total viable bacterial count was closely related to the pH of the aspirate and was independent of the cause of the hypochlorhydria; 90 per cent of aspirates of pH 1--2 were sterile, while 94 per cent of those of pH 4--8 contained bacteria . Escherichia coli was found significantly more frequently in the postoperative and cancer groups, and Clostridium spp . were significantly more common in patients with carcinoma . Elevated gastric juice nitrite concentrations were significantly more common in aspirates of pH 4--8 and this correlated well with the presence of nitrate-reducing bacteria . The pH of an aspirate is a good indicator of the presence of bacteria and may be useful in selecting patients requiring postoperative prophylactic antibiotic cover . Hypochlorhydric patients are exposed to increased concentrations of nitrite and there may be an increased risk of gastric cancer induced by N-nitrosocompounds. J Gen Microbiol, 1981 Aug, 125(Pt 2), 399 - 406 the involvement of Nitric Oxide in the inhibition of the phosphoroclastic system in Clostridium sporogenes by sodium nitrite; Woods LF et al.; The phosphoroclastic system was demonstrated in cell-free extracts of clostridium sporogenes by the production of carbon dioxide, acetyl phosphate, ATP and reduced NAD in the presence of pyruvate . The kinetics of acetyl phosphate production and NAD reduction were investigated . The addition of sodium nitrite to a suspension of C . sporogenes in glucose medium resulted in a rapid decrease in intracellular ATP concentration which was accompanied by an accumulation of pyruvate in the medium . This accumulation of pyruvate was caused by inhibition of phosphoroclastic system by nitrate . Nitrite inhibits this system by reaction of nitric oxide, formed from nitrate, with the non-haem iron of pyruvate:ferredoxin oxidoreductase. Am J Vet Res, 1981 Aug, 42(8), 1302 - 5 Introduction and reisolation of selected gram-positive bacteria from fermented edible wastes; Talkington FD et al.; A fermentation process using Lactobacillus acidophilus added to edible food wastes was evaluated for its bactericidal action on selected gram-positive organisms . The Lactobacillus fermentation converts food wastes into an animal feed ingredient . In this study, 5 gram-positive bacteria of zoonotic importance were individually tested . These organisms were: Group E Streptococcus, Erysipelothrix rhusiopathiae, Clostridium perfringens, Corynebacterium pseudotuberculosis, and Listeria monocytogenes . For each experiment, Lactobacillus was first mixed into ground waste; one of the test organisms was then inoculated and mixed . This mixture was divided among eight 5.5-L containers and incubated (duplicates) at 5 C, 10 C, 20 C, and 30 C for 96 hours . Internal waste temperature, reduction-oxidation, and pH were monitored . Waste samples were taken initially and at subsequent 24-hour periods . Qualitative and quantitative recoveries of the test bacteria were attempted for each sample . Group E Streptococcus was reisolated in increasing numbers at all temperatures throughout the fermentation period . Erysipelothrix rhusiopathiae was recovered throughout the 96-hour period at 5 C; at 10 C it was recovered at 24 hours but not at 48 hours . Erysipelothrix rhusiopathiae was killed by 24 hours at 20 C and 30 C fermentation temperatures . Clostridium perfringens survived the entire test period at 5 C, 10 C, and 20 C; it was killed by 72 hours at 30 C . Neither Corynebacterium pseudotuberculosis nor Listeria monocytogenes was reisolated at any temperature at any time. J Clin Microbiol, 1981 Aug, 14(2), 153 - 6 Hydrolytic enzymes of anaerobic bacteria isolated from human infections; Steffen EK et al.; Thirty-three strains of anaerobic bacteria isolated from human clinical specimens were examined for the presence of heparinase, hyaluronidase, chondroitin sulfatase, gelatinase, collagenase, fibrinolysin, lecithinase, and lipase activities . Pronounced heparinase activity was limited to species of the genus Bacteroides . A number of species of the genera Bacteroides and Clostridium produced hyaluronidase and chondroitin sulfatase . Gelatinase, collagenase, and fibrinolysin activities were encountered in isolates of the genera Bacteroides, Clostridium, and Peptostreptococcus . All strains capable of degrading collagen also hydrolyzed other protein substrates . Lipolytic activity was minimal among these anaerobic bacteria . No specific hydrolytic activity was consistently associated with the isolates. J Bacteriol, 1981 Aug, 147(2), 463 - 70 Substrate specificity of citrate lyase deacetylase of Rhodopseudomonas gelatinosa and Rhodopseudomonas palustris; Giffhorn F et al.; Citrate lyase (EC 4.1.3.6) isolated from Rhodopseudomonas palustris was investigated with regard to its kinetic properties and its subunit composition . This enzyme was inactivated by citrate lyase deacetylase (EC 3.1.2.-) of Rhodopseudomonas gelatinosa . A corresponding cross-reaction was measured with partially purified deacetylase of R . palustris and citrate lyase of R . gelatinosa . The three different subunit types (alpha, beta, and gamma) of citrate lyase from R . gelatinosa wee purified to homogeneity, and antibodies were prepared against each of the three subunits and against the native enzyme complex . In corresondence with the enzymatic interactions, immunological cross-reactions were found between anti-enzyme and anti-large subunit antibodies and citrate lyase from R . palustris . On the other hand, no immunological cross-reactions were detectable among each of the antibodies and citrate lyases from Enterobacter aerogenes, Streptococcus diacetilactis, and Clostridium sphenoides . Antibodies against the large subunit of citrate lyase inhibited the deacetylase, but antibodies against the middle and small subunits did not, indicating that the large subunits of citrate lyase are involved in binding the deacetylase. Biochim Biophys Acta, 1981 Jul 27, 654(2), 256 - 67 A basic isozyme of yeast glyceraldehyde-3-phosphate dehydrogenase with nucleic acid helix-destabilizing activity; Karpel RL et al.; A nucleic acid helix-destabilizing protein has been purified from Saccharomyces cerevisiae using affinity chromatographic techniques . Crude protein extracts at low ionic strength (approx . 0.05 M) were applied sequentially to tandem columns of native DNA-cellulose, aminophenyl-phosphoryl-UMP-agarose, poly(I . C)-agarose, poly(U)-cellulose and denatured DNA-cellulose . The 2 M NaCl eluant of the poly(U)-cellulose column was dialyzed to low ionic strength and recycled through native DNA-cellulose, poly(I . C)-agarose and poly(U)-cellulose . Purified helix-destabilizing protein eluted from the poly(U)-cellulose between 0.1 and 0.5 M NaCl . On the basis of enzymatic activity, immunological cross-reactivity, mobility on SDS gels, amino acid analysis and preliminary peptide mapping experiments, this material was identified as an isozymic fraction of glyceraldehyde-3-phosphate dehydrogenase . The major crystallizable isozyme of this enzyme from yeast is, however, considerably more acidic than the helix-destabilizing protein, and displays significantly lower helix-destabilizing activity . Stoichiometric levels of the isolated protein at low (approx . 0.01) ionic strength depress the Tm of poly(A-U) and poly {d(A-T)} by as much as 28 and 22 degrees C, respectively . Longer double helices, poly(A . U) and Clostridium perfringens DNA are also denatured by the helix-destabilizing protein, but at relatively slow rates . The binding of this protein to {3H}-poly(U) on nitrocellulose filters in {Na+}-dependent, with a 50% reduction at 0.09 M NaCl . Based on its effect on the circular dichroism spectrum of poly(A), the protein was shown to distort the conformation of the polynucleotide chain . An analogous protein from mammalian cells, P8, was also shown to depress poly(A-U) Tm. Jpn J Antibiot, 1981 Jul, 34(7), 1078 - 81 {The absorption, excretion and influence on bowel flora of oral paromomycin sulfate (author's transl)}; Iwaki S et al.; The absorption, excretion and influence on bowel flora of oral paromomycin sulfate (aminosidine, PRM) were studied in ten normal volunteers taking a normal diet, and the following results were obtained . 1 . Serum levels of PRM were observed 0.46 micrograms/ml at a half hour, 1.14 micrograms/ml at 1 hour, 1.48 micrograms/ml at 2 hours, 0.70 micrograms/ml at 4 hours, 0.29 micrograms at 6 hours and were almost faded out at 12 hours after 4 grams of oral administration . 2 . During 0 approximately 2 hours, 2 approximately 4 hours, 4 approximately 6 hours and 6 approximately 12 hours, the mean urine concentration of PRM were observed 56.4 micrograms/ml, 56.2 micrograms/ml, 37.1 micrograms/ml and 13.8 micrograms/ml, respectively, and the total excretion in the urine by 12 hours were observed 21.14 mg (0.53%) . 3 . Oral administration of PRM caused fall in Lactobacillus, non spore-forming anaerobic Gram positive bacilli (BEP group) and Peptostreptococcus (P less than 0.001), Bacteroides (P less than 0.01) . However, after administration was discontinued, reduced bowel flora was returned to the normal range within a few days . No overgrowth of bowel flora by coliform, Clostridium or yeast was observed . Klebsiella oxytoca and toxigenic Clostridium difficile were not observed overgrowth . 4 . No side effect was observed clinically over 2 months. Johns Hopkins Med J, 1981 Jul, 149(1), 6 - 9 Antimicrobial agents implicated in Clostridium difficile toxin-associated diarrhea of colitis; Bartlett JG; Records were reviewed for 329 patients who had antibiotic-associated diarrhea or colitis with stools showing a cytopathic toxin which is neutralized by Clostridium sordellii antitoxin . Previous studies indicate that the detection of this toxin implicate Clostridium difficile as the responsible pathogen . A spectrum of anatomical results in the colonic mucosa were found ranging from pseudomembranous colitis in 136 patients to an entirely normal endoscopic condition in 36 patients . The most frequently implicated agents were ampicillin, clindamycin, and cephalosporins . Collectively, these drugs accounted for approximately 80% of cases in which a single antimicrobial had been administered prior to the onset of symptoms . Analysis of data obtained in sequential time intervals showed a decline in the relative frequency of cases with use of clindamycin accompanied by an increase with use of cephalosporins . Less frequent drugs which were implicated in 3-8% of cases were, in rank order, penicillins other than ampicillin, erythromycin, sulfamethoxazole-trimethoprim and sulfasalazine . Tetracycline was the exclusive agent given to only three patients and there were no patients in whom chloramphenicol could be clearly implicated. Pediatrics, 1981 Jul, 68(1), 50 - 4 Potentiation of Clostridium botulinum toxin aminoglycoside antibiotics: clinical and laboratory observations; Santos JI et al.; A child with infant botulism became apneic and died while receiving ampicillin and gentamicin therapy . As aminoglycosides have been implicated in the induction and/or exacerbation of neuromuscular blockade, we used an animal model to test the hypothesis that aminoglycosides potentiate neuromuscular blockade of botulinum toxin . In the range of aminoglycoside doses utilized in these experiments, both gentamicin and tobramycin enhance neuromuscular impairment and death of botulinum toxin-exposed mice . These results support recently published clinical observations that aminoglycosides may potentiate neuromuscular weakness caused by botulinum toxin, and suggest that these antibiotics should be used with caution in suspected cases of infant botulism. Gastroenterology, 1981 Jul, 81(1), 5 - 9 Isolation rates and toxigenic potential of Clostridium difficile isolates from various patient populations; Viscidi R et al.; Stool specimens in various patient populations were examined to determine isolation rates of Clostridium difficile and the frequency with which this organism produces a cytopathic toxin in vitro . Clostridium difficile was isolated from 13 of 45 healthy neonates who had never received antimicrobials and the cytotoxin was detected in 12 . With 23 healthy children aged 4 to 24 mo the organism was recovered from 2 children and the cytotoxin was detected in 1 . Neither the organism nor the cytotoxin was found in specimens from healthy adults who denied antimicrobial usage during the prior 4 wk . Clostridium difficile was recovered from 12 of 56 adults receiving antimicrobials without diarrhea, but only one specimen yielded the cytotoxin . Both the cytotoxin and the organism were found in stools from most patients with antibiotic-associated colitis . Concentrations of Clostridium difficile, when present, were similar in all patient populations . Broth cultures of 165 isolates of Clostridium difficile showed all strains, but two produced the cytotoxin in vitro . However, the concentration of the toxin was substantially higher with strains recovered from patients with positive toxin assays . These observations indicate that neonates are often asymptomatic carriers of both Clostridium difficile and its cytotoxin . In adults, gastrointestinal symptoms correlated best with results of tissue culture assays and with toxigenic potential of the strains isolated. J Biochem (Tokyo), 1981 Jul, 90(1), 295 - 8 Correspondence of the larger subunit of the MoFe-protein in clostridial nitrogenase to the nif D gene products of other N2-fixing organisms; Hase T et al.; The amino(N)-terminal sequence of the larger subunit (alpha) of the MoFe-protein from Clostridium pasteurianum was determined up to 179 amino acid residues by analyses of BrCN and tryptic peptides of the original subunit . Apparent similarities exist among the sequence of the clostridial alpha-subunit, that of the smaller subunit (beta) of the Azotobacter vinelandii MoFe protein, and those predicted from the nucleotide sequences of nif D genes in Klebsiella pneumoniae and Anabaena 7120 . In comparing the sequences of C . pasteurianum and K . pneumoniae, 45% of residues are identical of a total of 184 sites . Therefore, the larger subunit of the clostridial MoFe-protein must correspond to the nif D gene product of K . pneumoniae. Pharmacotherapy, 1981 Jul-Aug, 1(1), 28 - 38 Metronidazole: in vitro activity, pharmacology and efficacy in anaerobic bacterial infections; Tally FP et al.; Metronidazole is a 5-nitroimidazole that has selective activity against anaerobic microorganisms, including bacteria and protozoa . Intravenous metronidazole has recently been approved by the U.S . Food and Drug Administration for the treatment of serious anaerobic bacterial infections . It is usually bactericidal at low concentrations, and its spectrum of activity encompasses almost all anaerobic bacteria and some capnophilic organisms . Anaerobic bacteria known to be resistant to metronidazole include occasional anaerobic cocci, some nonsporulating gram-positive bacilli and propionibacterium . Metronidazole is the most active antimicrobial agent against Bacteroides fragilis, the most resistant of anaerobic bacteria . Kill-curve studies demonstrate that there is a 2 to 5 log decrease in the number of colony forming units of B . fragilis and Clostridium perfringens within one hour . The only well documented metronidazole-resistant strain is a B . fragilis isolated from the normal flora of a patient on long-term metronidazole therapy for Crohn's Disease . Metronidazole resistance in Trichomonas vaginalis has recently been described in a few strains that are able to survive at increased oxygen tensions . Metronidazole has been shown to be efficacious in certain protozoal infections including trichomonal vaginitis, extraintestinal amebiasis, and giardiasis . Clinical studies have shown metronidazole to be efficacious in the therapy of a variety of anaerobic infections, including non-traumatic brain abscesses, intraabdominal sepsis, pelvic suppuration and necrotizing soft tissue infections . There have been disappointing results in the therapy of anaerobic pleuropulmonary infections with a number of superinfections caused by aerobic bacteria . Since metronidazole lacks any activity against aerobic bacteria, it must be combined with other agents, usually aminoglycosides, in the treatment of mixed infections involving anaerobic and aerobic bacteria. J Bacteriol, 1981 Jul, 147(1), 262 - 6 Isolation of a plasmid responsible for caseinase activity in Clostridium perfringens ATCC 3626B; Blaschek HP et al.; Clostridium perfringens strain ATCC 3626B was cured of caseinase activity at a high frequency after treatment with acriflavine dye (2.5%) or elevated temperature growth (9.1%) . Caseinase-negative isolates retained the larger (9.4 megadaltons) pHB102 cryptic plasmid, but were missing the smaller (2.1 megadaltons) pHB101 plasmid present in the caseinase-positive wild-type strain . Dye-buoyant density-gradient centrifugation at 4 or 15 degrees C revealed that the pHB101 and pHB102 plasmids are temperature labile and easily converted into the nicked non-supercoiled or linear state. Infect Immun, 1981 Jul, 33(1), 67 - 74 Intoxication of cultured human lung fibroblasts with Clostridium difficile toxin; Florin I et al.; The cytopathogenic effect of partially purified toxin from Clostridium difficile on cultured human lung fibroblasts was studied . Conditions for determination of 50% tissue culture dose were standardized . The cytopathogenic effect of the toxin was dependent on toxin concentration, exposure time, and density of the cells . Transfer of the cells to 0 degrees C did not inhibit binding of toxin to the fibroblast surface, but prevented the development of the cytopathogenic effect . Both binding of toxin and some intracellular step(s) were prevented by 2,4-dinitrophenol . These preventative effects were reversible . Before and concomitantly with the appearance of the cytopathogenic effect, the cellular uptake of uridine and of amino acids was markedly stimulated . Protein synthesis was depressed when 100% of the cells showed the cytopathogenic effect, but the synthesis of nucleic acids was inhibited only several hours later . The primary cellular target for the toxin is still unknown. Infect Immun, 1981 Jul, 33(1), 285 - 91 Purified Clostridium difficile cytotoxin stimulates guanylate cyclase activity and inhibits adenylate cyclase activity; Vesely DL et al.; Antibiotic-associated pseudomembranous colitis has been linked with Clostridium difficile toxin . We examined the effect of toxins from four strains of C . difficile isolated from patients with pseudomembranous colitis on colonic adenylate (EC 4.6.1.1) and guanylate cyclase (EC 4.6.1.2) activities . Partially purified toxins had a cytotoxic effect on hamster fibroblasts in culture at a concentration of 10 ng/ml . Likewise, these toxins enhanced colonic guanylate cyclase activity two- to threefold, with the maximal stimulation being at 10 ng/ml . These toxins also enhanced guanylate cyclase activity in ileum, cecum, and duodenum . Both the cytotoxic activity on hamster fibroblasts and the enhancement of hamster guanylate cyclase activity were inhibited by antiserum to C . difficile toxin . These same toxins inhibited adenylate cyclase activity at a 100-ng/ml concentration, but had no effect at 10 ng/ml . They also had no effect at any concentration on colonic Na+-K+ adenosine triphosphatase . To be sure that the findings were not due to a contaminant, a purified C . difficile cytotoxin was used, and the same findings were found with the pure cytotoxin (at a 100-fold-lower concentration) . The data suggest that activation of guanylate cyclase may be a factor in the pathogenesis of antimicrobial-associated pseudomembranous colitis. Antimicrob Agents Chemother, 1981 Jun, 19(6), 997 - 1003 Transferable tetracycline resistance in Clostridium difficile; Smith CJ et al.; The transfer of tetracycline resistance among strains of Clostridium difficile is described . Transfer occurred by a conjugation-like event that was insensitive to deoxyribonuclease, could not be mediated by donor culture filtrates or chloroform-treated donor cultures, and required cell-to-cell contact . Tetracycline-resistant progeny recovered from matings displayed a resistance phenotype identical to that of the donor in level of resistance, constitutive expression, and transmissibility . Although the original tetracycline-resistant donor contained 5 x 10(6)- and 22 x 10(6)-dalton plasmids, standard physical analyses of antibiotic-resistant transconjugants revealed no plasmid deoxyribonucleic acid molecules in common with the donor strain . Furthermore, tetracycline-susceptible derivatives of the original donor always possessed a plasmid complement identical to that of the resistant parental strain as determined by restriction endonuclease digestion analysis . The results indicate that the tetracycline resistance determinant(s) was not encoded by readily detectable plasmid deoxyribonucleic acid and may be chromosomally located. Ann Emerg Med, 1981 Jun, 10(6), 312 - 4 Nontraumatic clostridial myonecrosis: an infectious disease emergency; Leung FW et al.; A 64-year-old man presented with a history of four days of lower abdominal pain and 12 hours of cutaneous discoloration, bullae formation, and swelling of the soft tissues of abdominal wall and right thigh . Myonecrosis of abdominal wall and an adenocarcinoma of the cecum were found at operation . Cultures of blood and fluid from the bullae yielded Clostridium septicum . Nontraumatic clostridial myonecrosis is a fulminant, usually fatal disease that is most often the result of bacteremia from an occult gastrointestinal lesion . Ulceration of the colon or terminal ileum is the most common predisposing condition, and is usually due to gastrointestinal or hematological malignancy . Patients often present with nonspecific complaints, including pain at the affected site and fever . The disease progresses rapidly to include bronze discoloration, edema, and hemorrhagic bullous lesions of the skin, subcutaneous emphysema, and myonecrosis . Presumptive diagnosis often can be made by Gram stain of the bullous fluid that reveals gram-positive bacilli and a paucity of leukocytes . Favorable outcome depends on prompt institution of appropriate antimicrobial therapy and surgical debridement of involved soft tissues, as well as correction of the underlying disorder . This disease should be considered to be a medical-surgical emergency. Ann Emerg Med, 1981 Jun, 10(6), 307 - 11 Occult clostridial myonecrosis; Kizer KW et al.; Nontraumatic gas gangrene is extremely rare . It usually occurs following ulceration or perforation of an abdominal or pelvic viscus in persons having impaired host immune defenses . A fatal case of nontraumatic Clostridium septicum septicemia and myonecrosis in an elderly diabetic man with a perforated colon carcinoma is presented . The case illustrates the occult manner in which such cases typically present and the fulminant course of this disease . The need for rapid diagnosis and the current recommended treatment of gas gangrene are discussed. Hoppe Seylers Z Physiol Chem, 1981 Jun, 362(6), 809 - 20 The reduction of allyl alcohols by Clostridium species is catalyzed by the combined action of alcohol dehydrogenase and enoate reductase; Bader J et al.; Cells, as well as crude extracts of Clostridium kluyveri or Clostridium spec . La 1, catalyze the hydrogenation of (E)- or (Z)-2-butenol to n-butanol . No single enzyme could be detected which directly accomplishes this reaction . It turned out that the reduction occurs as follows: 2-butenol leads to 2-butenal leads to n-butanal leads to n-butanol . The first step is catalyzed by the NAD-dependent alcohol dehydrogenase in C . kluyveri, the second by the recently detected enoate reductase which reduces not only nonactivated alpha, beta-unsaturated acylates but also alpha, beta-unsaturated aldehydes in a NADH-dependent reaction and the third step is again catalyzed by alcohol dehydrogenase . In Clostridium La 1 the alcohol dehydrogenase is NADP-dependent . The rate of the reduction of 2-butenol to n-butanol depends not only on the enzymes, but also on the ratio NAD(P)/NAD(P)H . In the presence of methylviologen cation radical which is formed by the reduction of methylviologen by the system H2/hydrogenase, the ratio NAD(P)/NAD(P)H is too small for the dehydrogenation of 2-butenol to 2-butenal . This explains the antagonistic effect of methylviologen in the hydrogenation of allyl alcohols and 2-enoates by both Clostridium species . Furthermore, the mechanism explains the finding that from a preparative point of view ethanol is a better electron donor than hydrogen for the stereospecific reduction of allyl alcohols. Antimicrob Agents Chemother, 1981 Jun, 19(6), 980 - 6 Evaluation of eight cephalosporins in hamster colitis model; Ebright JR et al.; Eight commonly used cephalosporins were evaluated in the hamster colitis mode . They were all found to cause hemorrhagic cecitis and death within 10 days of being given as subcutaneous or oral challenges . Necropsy findings were indistinguishable from clindamycin-induced cecitis . Bacteria-free cecal filtrate obtained from hamsters dying of cephalosporin-induced cecitis contained toxin similar or identical to hat produced by Clostridium difficile isolated from the cecum of a hamster . Daily oral administration of poorly absorbed cephalosporins protected hamsters from clindamycin-induced cecitis and death as long as the cephalosporins were continued . The absorbable cephalosporins were ineffective in protecting hamsters from clindamycin-induced cecitis . This difference probably relates to the lower concentrations of absorbable cephalosporins maintained in the ceca of the hamsters . The possible correlation of these findings to human cases of cephalosporin-induced pseudomembranous colitis is discussed. Infect Immun, 1981 Jun, 32(3), 1187 - 92 Membrane-damaging action of alveolysin from Bacillus alvei; Thelestam M et al.; We investigated membrane damage to human diploid, embryonic lung fibroblasts caused by highly purified alveolysin by measuring leakage of cytoplasmic markers and uptake of various metabolites, and we observed a leakage pattern typical of SH-activated cytolysins . However, the mode of membrane interaction resembled the mode of membrane interaction of theta-toxin from Clostridium perfringens rather than that of streptolysin O in the following respects: the activity on fibroblast membranes was high compared with the activity on sheep erythrocytes; the toxin did not bind irreversibly to fibroblast cytoplasmic membranes; considerable membrane damage was caused at 0 degrees C; and inhibition of amino acid uptake occurred in the absence of significant structural membrane damage . These findings imply that data on membrane effects caused by streptolysin O cannot be related indiscriminately to other SH-activated cytolysins . With regard to the mode of membrane interaction, two apparently different groups of SH-activated cytolysins exist. Lab Anim Sci, 1981 Jun, 31(3), 259 - 62 Diet as a coadjuvant for development of antibiotic-associated diarrhea in hamsters (Mesocricetus auratus); Michelich VJ et al.; During a study of the effects of nutrition on experimental tumors in hamsters, fatal diarrhea developed . To determine the role of diet in this condition and the relationship between diet and antibiotics, two diets were used, ground commercial diet and a purified diet . Two antibiotics were used, neomycin sulfate and vancomycin . Diarrhea was evident soon after the animals were given the combination of purified diet and neomycin sulfate . Vancomycin initially acted as a suppressor of diarrhea, but hamsters fed the purified diet developed diarrhea after the drug was discontinued . None of the animals fed ground commercial diet treated with neomycin sulfate developed diarrhea . Clostridium difficile was isolated from most of the sick animals; all of the isolates of Clostridium difficile were toxigenic except one . No significant differences were seen among the Clostridium difficile isolated from different animals . Clostridium sporogenes and Clostridium tertium also were isolated from some of the animals. Biken J, 1981 Jun, 24(1-2), 13 - 21 Complementation characteristics of newly isolated mutants from two groups of strains of Clostridium perfringens; Imagawa T et al.; 1 . Mutants of a group were converted to b group by a second NG treatment . The resulting b group mutants could not produce the marker products that had been lost on the first NG treatment but could produce the others by complementation . 2 . Mutants of b group were converted to constitutive mutants by a second NG treatment . No back mutation from b group was observed. Biken J, 1981 Jun, 24(1-2), 1 - 11 Further studies on complementation between mutants of Clostridium perfringens; Tatsuki T et al.; 1 . Mutants devoid of lambda- and kappa-toxin and hemagglutinin (HA), respectively, were isolated from Cl . perfringens PB6K . The lambda- and HA- mutants could be classified into a and b groups by complementation but the kappa- mutants were all of the a group . 2 . All b group mutants isolated, irrespective of the marker used for isolation, were pleiotropically negative or leaky with respect to theta-, lambda- and kappa-toxin and HA production . 3 . Lambda-toxin produced by complementation was proved to be a rennet-like protease . 4 . The activities of 12 extracellular enzymes, including sialidase, of several b group strains and the parent PB6K were compared, but no definite differences were observed . From this finding, the productions of these enzymes were concluded not to be regulated by the same mechanism as theta-, lambda- and kappa-toxin and HA . 5 . Cl . perfringens CN3870 was also studied . Findings were similar to those on PB6K except for very low activity of HA. Ann Emerg Med, 1981 Jun, 10(6), 315 - 7 Clostridium perfringens: an unusual case of septic arthritis; Harrington TM et al.; Anaerobic joint infections may be a more common occurrence than previously reported . A nine-year-old with a septic knee due to Clostridium perfringens following a puncture wound was seen in the emergency department . Diagnosis was established by isolating the organism from an anaerobic synovial fluid culture . The patient was treated successfully with open drainage and parenteral penicillin . This case illustrates the necessity for specifically requesting anaerobic cultures on synovial fluid of patients with acute septic monoarthritis. Biochim Biophys Acta, 1981 May 29, 668(3), 325 - 32 Trypsin activation of enterotoxin from Clostridium perfringens type A: fragmentation and some physicochemical properties; Granum PE et al.; Clostridium perfringens type A enterotoxin was activated about 3-fold by treatment with trypsin, without an observed change in molecular weight . On denaturation in 8 M urea, the trypsinated enterotoxin lost a small peptide of about 4000 daltons . The single cysteine residue of enterotoxin was in the small peptide together with seven out of nine residues of proline . Trypsin activation, without removal of the small peptide, increased the 'outside' number of amino groups from eight to eleven . The trypsin treatment of the enterotoxin did not change the antigenic properties of the protein . Glycine was the C-terminal residue of the native enterotoxin while the dansyl alpha-amino acid of the N-terminal could not be identified. J Biol Chem, 1981 May 25, 256(10), 5153 - 61 RNA polymerase from Clostridium acidi-urici . Characterization of a naturally occurring rifampicin-resistant bacterial enzyme; Murray CL et al.; We report here the isolation of a prokaryotic RNA polymerase that shows pronounced template specificity . The enzyme from Clostridium acidi-urici is highly active on DNA templates isolated from phage that infect Gram-positive organisms and is essentially inactive at either high or low ionic strength on DNA from phage associated with Gram-negative bacteria . The enzyme is also unique among RNA polymerases isolated from wild type bacteria in being highly resistant to inhibition by rifampicin . These properties are characteristic of the enzyme present in several independently isolated strains of C . acidi-urici . However, RNA polymerase present in other clostridial species resembles the enzyme present in Bacillus subtilis in sensitivity to rifampicin and template specificity. Wien Klin Wochenschr, 1981 May 15, 93(10), 331 - 6 {Anaerobic bacteria in clinical specimens of a hospital laboratory (author's transl)}; Mittermayer H; Over a 14-month period 261 clinical specimens were cultured anaerobically, this figure representing about 3% of the total specimens submitted to the microbiological laboratory . Not accepted for anaerobic culture were stools, sputa, urines, vaginal and urethral swabs and swabs from superficial skin lesions . All materials were sent to the laboratory in an anaerobic transport medium and processed according to the recommendations of the American Society for Microbiology and the Center for Disease Control, Atlanta, Georgia . Not included in this figure are blood cultures and cultures from removed venous catheters . 35% of the specimens contained anaerobes . 169 anaerobic strains were isolated . 78 of them belonged to the Bacteroides fragilis group . Clostridium perfringens was found in only 7 cases . 14% of the strains were B . melaninogenicus, 7% other gram-negative non-sporeforming rods . In most of the cases a mixed aerobic-anaerobic flora was found . More than 75% of specimens obtained from infections originating from the lower intestinal tract yielded growth of anaerobes . In infections of the bile duct anaerobes were found in 25% of the cases . In infections of the upper urinary tract anaerobes played no major role . 35% of the isolates of the B . fragilis group were resistant to tetracycline, 17% to cefoxitin and 9% to clindamycin. Experientia, 1981 May 15, 37(5), 451 - 2 On the production of 12 alpha-hydroxysteroid dehydrogenase from Clostridium group P, strain C48-50 ATCC 29733; Macdonald IA; The production of 12 alpha-hydroxysteroid dehydrogenase of Clostridium group P strain C48-50 was optimized when the organism was grown in the presence of 2% fructose and 0.1% dithiothreitol . It appears that an initial redox potential of less than -160 mV (achieved by autoclaving in the presence of dithiothreitol, dithioerythritol or cysteine) is important in the production of this enzyme. Biochemistry, 1981 May 12, 20(10), 2908 - 16 Phase behavior of ether lipids from Clostridium butyricum; Goldfine H et al.; Ether lipids have been isolated from the phospholipid fraction of Clostridium butyricum IFO 3852 cells which had been grown in media devoid of biotin with added elaidic acid or oleic acid . The plasmalogen form of phosphatidylethanolamine (plasmenylethanolamine) from elaidate-grown cells was highly enriched with 18:1 in both the alk-1-enyl and acyl chains . A transition from the gel to liquid-crystalline state, with a peak maximum (Tm) at 33 degrees C and enthalpy delta H = 5.7 kcal/mol, was observed by differential scanning calorimetry . With the fluorescent probes cis- and trans-parinaric acids, transitions were observed at 33 degrees C on heating and at 29 degrees C on cooling . These transition temperatures are 5-6 degrees C lower than those reported for the corresponding diacyl lipid, dielaidoylphosphatidylethanolamine . A similar study of the phase behavior of both the elaidate-enriched and oleate-enriched glycerol acetal derivative of plasmenylethanolamine from C . butyricum revealed a large hysteresis of 12.5-16 degrees C . Hysteresis in the polar head group motion was also observed by 31P nuclear magnetic resonance . The elaidate-enriched lipid, which melted between 28 and 33 degrees C, appears to undergo supercooling prior to the transition to the gel state at about 18-13 degrees C, depending on the scanning rate . The formation of a more ordered gel state relative to plasmenylethanolamine was indicated by a 2-fold increase in delta H . Electron microscopy revealed a marked reorganization from typical multilamellar liposomes above Tm to large needle-like structures below Tm . The oleate-enriched glycerol acetal lipid formed the gel phase at -4 degrees C, which is 10 degrees C above the transition temperature reported for dioleoylphosphatidylethanolamine . Stabilization of oleate-enriched glycerol acetal lipid bilayers may result from hydrogen bonding between polar head groups . The relationship of the phase behavior of the ether lipids to the lipid composition and phase behavior of C . butyricum membranes is discussed. Mikrobiologiia, 1981 May-Jun, 50(3), 458 - 66 {Fermentation products and the pectolytic enzymatic activity in Clostridium felsineum strains differing in intensity of sporulation}; Avrova NP et al.; Clostridium felsineum strains differing in the activity of pectolytic enzymes and the rate of spore formation varied also in the synthesis of fermentation products . Strains with the high rate of spore formation synthesized less butyric and propionic acids, but twice as much butanol; as a result, the proportion between butyric acid and butanol was 8 times as low as in the strains forming a small quantity of spores . The strains with the high activity of pectolytic enzymes contained 6.7 times more acetic acid, 3.5 times more ethanol and 2.7 times less propanol. J Am Acad Dermatol, 1981 May, 4(5), 619 - 29 Pseudomembranous (antibiotic-associated) colitis; Saco LS et al.; We have come to understand the cause of antibiotic-associated pseudomembranous colitis (PMC) only in the last decade . Clostridium difficile produces the intestinal dysfunction and the characteristic finding of exudative plaques on the mucosa by elaborating a toxin in the colon . This report reviews the development of our knowledge of this disease and the rapid adoption of a rational therapy once the cause was specified . C . difficile or its toxin can be cultured or isolated from the stools of 90% of the patients with PMC . This organism is almost never found in healthy people or in any other conditions except inflammatory bowel disease, where its significance is not yet known . The detection of pseudomembranes by sigmoidoscopy establishes the diagnosis . The laboratory technics that confirm the presence of C . difficile and its toxin are being incorporated into many laboratories around the country . Treatment of diagnosed PMC is relatively simple and usually completely effective . The offending antibiotic is stopped, a proper fluid and electrolyte balance maintained, and oral vancomycin begun, 125 to 500 mg four times a day . Cholestyramine can also be used as an adjunct to this regimen . Relapse can occur in patients treated with oral vancomycin, necessitating a repeat course of therapy. Appl Environ Microbiol, 1981 May, 41(5), 1184 - 91 Relationship of sporulation, enterotoxin formation, and spoilage during growth of Clostridium perfringens type A in cooked chicken; Craven SE et al.; Sporulation and enterotoxin formation were determined for 17 strains of Clostridium perfringens type A in autoclaved chicken dark meat and in Duncan-Strong sporulation medium . The mean numbers of heat-resistant spores detected after 24 h at 37 degrees C were log10 1.13 to log10 7.64/ml in Duncan-Strong medium and log10 4.93 to log10 6.59/g in chicken . Of 17 strains, 7 formed enterotoxin in Duncan-Strong culture supernatant (1.0 to 60 microgram/ml) and 8 produced enterotoxin in chicken (0.21 to 24 microgram/g) . Additional studies with chicken were conducted with C . perfringens NCTC 8239 . With an inoculum of 10(6) cells per g, greater than log10 7.99 vegetative cells per g were detected by 4 h in chicken at 37 degrees C . Heat-resistant spores occurred by 4 and 6 h and enterotoxin occurred by 8 and 6 h in autoclaved chicken dark meat and barbecued chicken drumsticks, respectively . Enterotoxin was detected in autoclaved dark meat after incubation at 45 degrees C for 1.5 h followed by 37 degrees C for 4.5 h, but not after incubation at 45 degrees C for 1.5 to 8 h . With an inoculum of 10(2) cells per g in oven-cooked or autoclaved chicken, greater than log10 8.00 vegetative cells per g were detected by 6 to 8 h at 37 degrees C, heat-resistant spores were detected by 8 h, and enterotoxin was detected by 12 h . A statistical analysis of odor determinants of chicken after growth of C . perfringens indicated that, at the 95% confidence level, the product was considered spoiled (off or unwholesome odor) by the time spores or enterotoxin were formed. J Clin Microbiol, 1981 May, 13(5), 940 - 6 Highly sensitive assay for Clostridium perfringens enterotoxin that uses inhibition of plating efficiency of Vero cells grown in culture; McDonel JL et al.; A highly sensitive and reproducible biological assay for Clostridium perfringens enterotoxin is described that uses Vero (African green monkey kidney) cells grown in tissue cultures . Very small doses of the enterotoxin inhibited the plating efficiency of the cells . This inhibition of plating efficiency could be used to detect as little as 0.1 ng (1 ng/ml) of enterotoxin, and a linear dose-response curve was obtained with 0.5 to 5 ng (5 to 50 ng/ml) . A nonlinear, but reproducible, curve was obtained with a dose range from 0.1 to 100 ng (1 to 1,000 ng/ml) . A new unit of biological activity, called the plating efficiency unit, was defined as that amount of enterotoxin that caused a 25% inhibition of the plating of 200 cells inoculated into 100 microliters of medium in a microwell culture system . One milligram of highly purified enterotoxin contained about 400,000 plating efficiency units . Additional studies demonstrated that the biological and serological activities of the enterotoxin molecule were not equally labile. Am J Physiol, 1981 May, 240(5), C234 - 8 Enzymatic isolation of cells from bone: cytotoxic enzymes of bacterial collagenase; Hefley T et al.; The enzymatic isolation of cells from fetal rat calvaria is most effectively achieved with crude Clostridium histolyticum collagenase . However, this bacterial collagenase damages the cells during the digestion of the tissue . We have used cell density, as measured by isopycnic centrifugation on polysucrose gradients, as an indicator of cell damage . There are at least two enzymes in crude bacterial collagenase capable of damaging the cells in this tissue . One of these is clostripain that has been well characterized . The other cytotoxic enzyme is uncharacterized, and its effects are not evident until the clostripain activity has been inhibited by alpha-tosyl-lysyl chloromethane . The apparent activity of this second enzyme can be inhibited by withholding magnesium from the digestion medium and by increasing the potassium concentration of the digestion medium. Arch Surg, 1981 May, 116(5), 537 - 40 Elective cholecystectomy . The role of biliary bacteriology and administration of antibiotics; Farnell MB et al.; One hundred patients who underwent elective cholecystectomy were studied prospectively to define the accuracy of an intraoperative Gram's stain procedure in discovering the presence of bactibilia, the apparent necessity for prophylactic use of antibiotics, and the resulting septic complication rate . Antibiotics were used for prophylaxis in 48 patients and were withheld from 52 . Intraoperative Gram's stain procedure and culture were used in all cases . Bactibilia was present in 23% of the group and was accurately predicted by Gram's stain in 87% of all . The only septic complication was a stitch abscess in one patient in the group that received antibiotics . The presence of bactibilia does not seem to be associated with an increased incidence of infectious complications in elective cholecystectomy for chronic cholecystitis . Routine use of Gram's stain should detect the presence of Gram-positive rods (Clostridium), thus allowing early initiation of appropriate treatment. J Biol Chem, 1981 Apr 25, 256(8), 3712 - 7 Separation and characterization of heavy and light chains from Clostridium botulinum type C toxin and their reconstitution; Syuto B et al.; Clostridium botulinum type C toxin consists of a heavy and a light chain with molecular weights of 98,000 and 53,000, respectively, which are linked by one disulfide bond . The two components were separated from each other by quaternary aminoethyl Sephadex A-50 column chromatography by stepwise elution with NaCl in 27.5 mM borax-45 mM sodium dihydrogen phosphate buffer, pH 8.0, containing 5% 2-mercaptoethanol at 0 degrees C . The purified components had different amino acid compositions and antigenicities, and the toxicity of the toxin was neutralized completely by either anti-heavy chain Fab or anti-light chain Fab . the two components could be reconstituted to form an active molecule with recovered toxicity which varied according to the method used . Maximum recovery was obtained in a system in which the intersubunit S--S bond was first formed in the presence of high concentration of neutral salts, after which the concentration of salt was gradually decreased . The reconstituted preparation was highly toxic and had the same properties as the parental toxin on chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunodiffusion . By the use of three perturbants, the fractions of exposed tryptophans and tyrosines of the preparation were found to be almost the same as that of the parental toxin. Biochim Biophys Acta, 1981 Apr 17, 674(1), 118 - 27 Influence of cations on lysozyme-induced germination of coatless spores of Clostridium perfringens 8-6; Sacks LE; Bacterial endospore germination is powerfully influenced by inorganic salts, cations having especially important effects . Spores of Clostridium perfringens 8-6 are unusual in lacking a spore coat; these spores germinate only in the presence of lysozyme, which readily digests the exposed cortex . Lysozyme-induced germination showed the same response to ionic strength and valence of cations as does lysozyme hydrolysis of peptidoglycan, and close parallels are evident in the influence of inorganic cations on germination of normal spores . La3+ and transition element cations inhibited lysozyme-induced germination at low concentration, again demonstrating parallels with their action on lysozyme digestion of peptidoglycan and on the germination of normal spores . The poly-cations poly(L-lysine) and Ruthenium Red inhibited at extremely low concentrations . Mn2+ and Co2+, at appropriately low concentrations, stimulated lysozyme germination of 8-6 spores and also lysis of Micrococcus lysodeikticus. Jpn J Med Sci Biol, 1981 Apr, 34(2), 61 - 8 Separation of Clostridium botulinum type A derivative toxin into two fragments; Kozaki S et al.; Two fragments with molecular weights of 105,000 (fragment I) and 58,000 (fragment II) were separated chromatographically from each other after Clostridium botulinum type A derivative toxin adsorbed onto a QAE-Sephadex column was treated with dithiothreitol and urea . They were antigenic and formed crossing precipitin lines against anti-derivative toxin in agar gel diffusion tests . Upon removal of dithiothreitol and urea by dialysis, the two fragments reassembled to reconstruct the derivative toxin molecule. J Clin Pathol, 1981 Apr, 34(4), 416 - 9 IgG antibodies against anaerobic bacteria in blood donor sera; Schwan A; Fifty-six blood donor sera were examined by indirect immunofluorescence for IgG antibodies to a selection of anaerobic bacterial strains, often isolated from wound cultures . Another 25 sera were examined by IgG antibodies to six NCTC Bacteroides strains . A wide range of IgG antibody titres were found against Fusobacterium, Clostridium, and anaerobic streptococcal species . Very low titres were found against the Bacteroides strains . It is suggested that the testing of a single serum specimen for IgG antibodies against a representative collection of Bacteroides fragilis strains could be helpful in verifying a clinical suspicion of infection with these organisms. J Clin Pathol, 1981 Apr, 34(4), 414 - 5 Antitoxin production in antibiotic-associated colitis? Lishman AH, Al-Jumaili IJ, Record CO. The production of antitoxin after Clostridium difficile-induced diarrhoea has not been reported previously . The stool of a patient with prolonged antibiotic-associated diarrhoea contained C . difficile toxin, and the serum neutralised the cytopathic effect of C . difficile toxin in tissue culture. Appl Environ Microbiol, 1981 Apr, 41(4), 1074 - 7 Identification, distribution, and toxigenicity of obligate anaerobes in polluted waters; Daily OP et al.; A seasonal occurrence of obligately anaerobic bacteria, predominantly of the genera Bacteroides and Clostridium, in a polluted water site has been observed . The number of anaerobes varied from 1.8 X 10(3) cells/ml in the warmer months to 10 cells/ml in winter . Several isolates were toxigenic, indicating a potential human health hazard. Arch Intern Med, 1981 Apr, 141(5), 663 - 4 Recurrent pseudomembranous colitis unassociated with prior antibiotic therapy; Moskovitz M et al.; Fulminant and recurring pseudomembranous colitis developed in an elderly woman without prior antibiotic administration within the previous year . Stool culture yielded Clostridium difficile, and tissue cultures showed C difficile cytotoxin . Treatment with vancomycin hydrochloride was initially successful, but a serious relapse after its discontinuation necessitated low-dose long-term prophylaxis . Clostridium difficile may be responsible for pseudomembranous colitis unassociated with antibiotic therapy. Am J Med, 1981 Apr, 70(4), 906 - 8 Epidemiology of antibiotic-associated colitis; isolation of Clostridium difficile from the hospital environment; Fekety R et al.; Clostridium difficile is the most important cause of antibiotic-associated colitis . Using selective media, it was found that contamination with this organism was common in the environment of patients in the hospital with the disease . It was often found on floors, hoppers, toilets, bedding, mops, scales and furniture . This organism was also present on these items, but less often, in areas in which patients known to carry this hardy spore-forming organism had not been detected . Air, food and walls were negative . The organism was isolated from the hands and stools of asymptomatic hospital personnel . It was also found on surfaces in a patient's home . The importance of the various sources of the organism in its spread in the hospital is not known, and further studies are needed . It is suggested that enteric isolation precautions, and careful handwashing and cleansing of potentially contaminated surfaces and objects may be worthwhile when cases of antibiotic-associated colitis are identified. J Am Vet Med Assoc, 1981 Apr 1, 178(7), 732 - 4 Suppurative abomasitis associated with Clostridium septicum infection; Eustis SL et al.; A 1-week-old calf and two 1-month-old lambs from different farms in eastern South Dakota had severe abomasitis characterized by diffuse suppurative inflammation, edema, and emphysema . Clostridium septicum in the abomasal wall of each was identified by immunofluorescence and isolation . The lesions and microbiologic findings established the disease as braxy, a condition infrequently reported in the United States and thought to affect sheep only. Gastroenterology, 1981 Apr, 80(4), 697 - 70 Occurrence of Clostridium difficile toxin during the course of inflammatory bowel disease; Meyers S et al.; Clostridium difficile toxin, the presumed mechanism of antibiotic-associated pseudomembranous colitis, has been suggested as a contributory factor to mucosal injury in inflammatory bowel disease . We evaluated its incidence and apparent role in 65 consecutive patients with diarrheal and inflammatory bowel diseases . Toxin was demonstrated in 3 of 18 patients with ulcerative colitis (17%), 1 of 26 with Crohn's colitis (4%), and 5 of 21 with a variety of diarrheal illnesses (24%) . Toxin appeared only in those who had been exposed to antimicrobials within 2 mo . In inflammatory bowel disease, presence of toxin was not correlated with disease severity . We conclude that Clostridium difficile toxin appears only in patients exposed to antimicrobials and is unlikely to be a significant contributory factor in inflammatory bowel disease. Appl Environ Microbiol, 1981 Apr, 41(4), 1078 - 80 Microbial profiles of country-cured hams aged in stockinettes, barrier bags, and paraffin wax; Draughon FA et al.; No significant differences were found in surface microflora of county-cured hams covered with stockinettes, barrier bags, or a coating of paraffin wax during aging, except for a reduction in mold growth on waxed hams . The incidence of Clostridium spp . was lost in all treatments . Micrococcus spp . and Streptococcus spp . were the most common contaminants, but caused no apparent spoilage problem in any treatment. Am J Epidemiol, 1981 Apr, 113(4), 436 - 44 Restaurant-associated type A botulism: transmission by potato salad; Seals JE et al.; In the period November 13-18, 1978, seven cases of type A botulism occurred in persons who had eaten in a restaurant in Colorado . The outbreak was recognized when two persons who had independently eaten at the restaurant were hospitalized with an illness compatible with botulism . Surveillance efforts identified five additional cases . Potato salad made at the restaurant and available for service during an 11-day period was epidemiologically incriminated as the vehicle of botulinal toxin transmission (p less than 0.00001) . Laboratory studies showed that Clostridium botulinum spores on the surface of potatoes could survive baking in the manner used by the restaurant and that botulinal toxin could be produced in potatoes contaminated with C . botulinum spores. J Neurosurg, 1981 Apr, 54(4), 455 - 60 High-dose BCNU with autologous bone marrow rescue for recurrent glioblastoma multiforme; Hochberg FH et al.; Eleven patients with recurrent malignant glioma were treated with single high doses of BCNU ranging from 600 to 1400 mg/sq m . To prevent the characteristic late myelosuppression observed after conventional doses of BCNU, autologous bone marrow harvested just before drug treatment was infused 24 to 36 hours after therapy . Higher doses of BCNU causes earlier and more profound myelosuppression; one patient died on pancytopenia, breakdown of the gut epithelium, and Clostridium septicemia 10 days after receiving 1400 mg/sq m of BCNU . All patients experienced transient emesis; four developed transient elevation of hepatic enzymes, two reversible interstitial pulmonary infiltrates, and two who received 1400 mg/sq m BCNU suffered irreversible cortical damage . Eight patients receiving 600 to 1200 mg/sq m demonstrated reconstitution of polymorphonuclear leukocytes an platelets within at least 30 days after treatment . With a follow-up time of up to 19 months, four patients improved, three stabilized, and three deteriorated and died . The median survival time was 7 months . Computerized tomography performed on patients receiving constant corticosteroids showed diminished contrast enhancement and mass effect in eight patients . High-dose BCNU at doses up to 1200 mg/sq m with marrow rescue is a feasible approach to the treatment of patients with glioblastoma. J Biol Chem, 1981 Mar 25, 256(6), 2808 - 12 Nucleotide sequence of the gene coding for the nitrogenase iron protein from Klebsiella pneumoniae; Sundaresan V et al.; We report the complete DNA sequence of the Klebsiella pneumoniae nifH gene, the gene which codes for component 2 (Fe protein or nitrogenase reductase) of the nitrogenase enzyme complex . The amino acid sequence of the K . pneumoniae nitrogenase Fe protein is deduced from the DNA sequence . The K . pneumoniae Fe protein contains 292 amino acids, has a Mr = 31,753, and contains 9 cysteine residues . We compare the amino acid sequence of the K . pneumoniae protein with available amino acid sequence data on nitrogenase Fe proteins from two other species, Clostridium pasteurianum and Azotobacter vinelandii . The C . pasteurianum Fe protein, for which the complete sequence is known, shows 67% homology with the K . pneumoniae Fe protein . Extensive regions of strong conservation (90-95%) are found, while other regions show relatively poor conservation (30-35%) . It is suggested that these strongly conserved regions are of special importance to the function of this enzyme, and the findings are discussed in the light of evolutionary theories on the origin of nif genes. J Biol Chem, 1981 Mar 10, 256(5), 2199 - 206 Magnetic interactions between dysprosium complexes and two soluble iron-sulfur proteins; Blum H et al.; A tetranuclear ferredoxin from Rhodopseudomonas gelatinosa {4Fe-4S}(+2,+3) has been examined by electron paramagnetic resonance techniques . The temperature-dependence and relaxation characteristics of the spectral lines indicate that the spin-lattice interaction is described at low temperatures by a T2 law which gives way to a T9 Raman relaxation as the temperature is raised . At higher temperatures an Orbach process becomes dominant . In the presence of dysprosium complexes the relaxation and line widths are modified . From crystallographic structure determinations of similar proteins we are able to relate the dysprosium effects to the spatial separation between the complex and the tetranuclear cluster . This scale is then tested against a ferredoxin from Clostridium pasteurianum which contains two tetranuclear clusters, {4Fe-4S}(+1,+2) . We find that for these soluble iron-sulfur proteins the dysprosium complexes form a shell at the protein surface . The magnetic interaction between the clusters and the complexes altering the relaxation time goes as r-6, while the low temperature line broadening is described by an r-3 dipole interaction. Schweiz Med Wochenschr, 1981 Mar 7, 111(10), 350 - 5 {Mild spontaneous course of a case of pseudomembranous colitis . Case report and literature review}; Jaeger A et al.; Pseudomembranous colitis (PMC) caused by a toxin produced by Clostridium difficile is described in the literature as a severe diarrheal disease with a high mortality rate . A case which tends to absolve PMC from this reputation is reported involving an outpatient who developed well documented PMC subsequent to ampicillin therapy but required no treatment . The number of unreported cases of antibiotic-associated colitis with and without pseudomembrane formation is probably very high, since only severe cases of diarrhea are thoroughly investigated . In a chronological literature review an attempt is made to update the nomenclature of antibiotic-associated colitis . There are recent reports of a connection between the Clostridium difficile toxin and the chronic inflammatory "non-bacterial" intestinal diseases ulcerative colitis and Crohn's disease . The authors finally consider whether in cases of antibiotic-associated diarrhea efforts should be made to isolate Clostridium difficile and/or demonstrate the presence of its toxin, for the purposes of prognosis and therapy. Biochim Biophys Acta, 1981 Mar 6, 641(2), 401 - 9 Protective effects of osmotic stabilizers on morphological and permeability alterations induced in Vero cells by Clostridium perfringens enterotoxin; McClane BA et al.; Culture medium made hypertonic by the addition of osmotic stabilizers such as sucrose, poly(ethylene glycol), dextran and bovine serum albumin protected against changes in morphology and plasma membrane permeability induced by Clostridium perfringes enterotoxin . The protection did not appear to be due to binding inhibition . Results of these studies support an osmotic disruption mechanism for the action of the enterotoxin . A comprehensive model of the enterotoxin's action based on an osmotic disruption mechanism is proposed. Zentralbl Bakteriol A, 1981 Mar, 249(1), 99 - 103 Oxygen-dependent metronidazole-resistance of Clostridium histolyticum; Fuzi M; Sensitivity determinations with 6 strains of Clostridium histolyticum showed that the inhibitory action of metronidazole was highly dependent on the oxygen concentration of the environment . Under anaerobic conditions they were sensitive but at increased oxygen concentrations moderately sensitive or resistant . The flexible resistance of this aerotolerant anaerobe against metronidazole may interfere with results of sensitivity determinations, estimation of blood levels and it may influence the effectiveness of the drug in anaerobic infections due to aerotolerant anaerobes. Aust Fam Physician, 1981 Mar, 10(3), 177 - 80 Tetanus; Feery BJ; Tetanus results from the action of a powerful exotoxin produced by Clostridium tetani . It can be prevented only by active and passive immunization procedures . The vaccine is one of the safest and most effective vaccines ever developed, and is capable of inducing long term protection in individual vaccinees . Adequate immunization before, or during pregnancy can eliminate the risk of neonatal tetanus in infants born in developing countries . In non-immune patients, tetanus prophylaxis requires the use of tetanus immunoglobulin, or tetanus antiserum in addition to adequate wound care. Pediatrics, 1981 Mar, 67(3), 381 - 6 Antibiotic-associated pseudomembranous colitis in children; Viscidi RP et al.; Ten cases of antibiotic-associated pseudomembranous colitis in children are reviewed . The ages ranged from 4 years to 17 years; the most frequently implicated antimicrobial agents were penicillins in six children and clindamycin in two . Stool assays showed specimens from all ten patients yielded a cytopathic toxin which was neutralized by Clostridium sordellii antitoxin with titers ranging from 1:40 to 1:40,000 . Bacterial cultures of nine specimens uniformly yielded Clostridium difficile with a median concentration of 10(5.4) organisms per gram of wet weight . All nine isolates of C difficile showed a vitro production of a cytopathic toxin which was similar to or identical with that which was detected in the original stool specimen . All ten patients recovered . Six were treated with oral vancomycin and showed a good therapeutic response; one patient, however, suffered two relapses when treatment was discontinued, requiring a total of three courses of oral vancomycin . Two patients received cholestyramine and responded well . These observations provide supportive evidence that C difficile is responsible for antibiotic-associated pseudomembranous colitis in children and document efficacy of the newer therapeutic modalities in this patient population as well. Dig Dis Sci, 1981 Mar, 26(3), 218 - 24 Bacteria and gallstones . Etiological significance; Tabata M et al.; Two hundred consecutive gallstone cases have been subjected to bacteriological study employing improved anaerobic culture techniques . In addition to Clostridia species, species of anaerobes such as Bacteroides fragilis, Peptococcus, Veillonella, and Eubacterium are found to be present, some of which possessed beta-glucuronidase activity . This finding has a certain bearing on the etiology of bile pigment calcium stones . In addition to Escherichia coli, Bacteroides and Clostridium often found in the biliary tract may contribute to the formation of bile pigment calcium stones by producing beta-glucuronidase and thus deconjugating bilirubin diglucuronide to form free unconjugated bilirubin which in turn combines with calcium, leading to stone formation . In contrast, very low bacterial incidence was associated with cholesterol stones and so-called black stones--sometimes called pure pigment stones--and thus bacteria play little role, if any, in their formation . Therefore, bile pigment calcium stones and so-called black stones, which are often classified as pigment stones indiscriminately, should be differentiated not only because of their difference in their appearance and composition but also in their etiological background . Regardless of the kind of stones present in the common duct, the incidence of bacteria was found to be increased. Arch Microbiol, 1981 Mar, 129(1), 49 - 52 Role of hydrogen sulfide in mercury resistance determined by plasmid of Clostridium cochlearium T-2; Pan-Hou HS et al.; Mercury resistance of Clostridium cochlearium T-2P was found to be controlled by a different mechanism from those reported so far since no mercury-reducing activity was detected in this strain . The H2S generating ability as well as the demethylating activity in this bacterium was eliminated by the treatment of the cured acridine dye and recovered by the conjugation of the cured strain with the parent strain . In addition, the strain which lost their abilities to generate H2S and to decompose methylmercury, showed higher sensitivity to mercurials than the parent strain . From these results, the genes conferring both the activities seemed to reside on the plasmid and the mechanism of mercury resistance was probably based on a detoxification mechanism involving methylmercury decomposition and inactivation of the inorganic mercury with H2S. Appl Environ Microbiol, 1981 Mar, 41(3), 737 - 45 Isolation and characterization of thirteen intestinal microorganisms capable of 7 alpha-dehydroxylating bile acids; Hirano S et al.; Thirteen anaerobic bacteria capable of performing the 7 alpha-dehydroxylation of both cholic acid and chenodeoxycholic acid were isolated from human feces and also from sewage . Ten organisms from heat-treated samples were species of Clostridium identical or closely related to the Clostridium bifermentans-C . sordellii group and consisted of four strains elaborating 7 alpha-dehydroxylase alone and six strains capable of catalyzing both 7 alpha-dehydrogenation and 7 alpha-dehydroxylation . The remaining three organisms, recovered from fresh human feces, were gram-positive, nonflagellated, nonsporeforming, anaerobic rods and comprised two distinct species . Strain HD-17, still unidentified, had both activities, but was unique in that it exclusively 7 alpha-dehydroxylated cholic acid while biotransforming chenodeoxycholic acid, preferably though 7 alpha-dehydrogenation . Two unclassified strains, b-8 and c-25, metabolized both acids though 7 alpha-dehydroxylation and 7 alpha-dehydrogenation . Except for strains b-8 and c-25, all of th 7 alpha-dehydroxylating bacteria split the conjugated bile acid series, and hydrolases were detected in cell-free filtrates of early stationary-phase broth cultures. Ann Surg, 1981 Mar, 193(3), 361 - 4 Clostridium septicum infection and malignancy; Katlic MR et al.; Evidence mounts favoring the relationship, albeit unexplained, between Clostridium septicum infection and malignancy, particularly hematologic or intestinal malignancy . Seven patients with C . septicum gangrene or sepsis have been treated at the Massachusetts General Hospital in the years 1977-79 . All of these patients have had associated malignant disease: four patients had colon adenocarcinomas, two patients had acute myeloblastic leukemias, and one patient had breast carcinoma . In six of the seven patients, the malignancy was in an advanced state; the breast carcinoma showed no evidence of recurrence after mastectomy, 17 years earlier . A bowel portal of entry is postulated in five patients . Despite prompt use of appropriate antibiotics, the only survivors were two of the four patients who underwent early extensive debridement . These results suggest that, in the patient with C . septicum infection, malignancy should be sought; that, in the septic patient with known malignancy, C . septicum should be considered; and that, in the absence of external source in the patient with clostridial myonecrosis or sepsis, the cecum or distal ileum should be considered a likely site of infection . Increased awareness of this association between C . septicum and malignancy, and aggressive surgical treatment, may result in improvement in the present 50-70% mortality rate. Ann Microbiol (Paris), 1981 Mar-Apr, 132(2), 149 - 57 {Detection of "Clostridium difficile" on minimal and selective medium and by immunofluorescence antibody staining (author's transl)}; Hubert J et al.; A minimal and selective medium containing 5 aminoacids, 3 vitamins, a low sugar concentration and 2 antibiotics (cefoxitin at 16 microgram/ml and streptomycin at 500 microgram/ml) is described for isolation of Clostridium difficile from the gut . Comparable results were obtained with this medium and using spore isolation by the sodium thioglycolate-lysozyme technique . An antiserum specific to C . difficile was prepared and used for detection by immunofluorescent antibody staining . This is a very sensitive technique which leads to a quick and early identification of this bacterial species. Infect Immun, 1981 Mar, 31(3), 890 - 5 Vascular permeability activity of botulinum C2 toxin elicited by cooperation of two dissimilar protein components; Ohishi I et al.; Botulinum C2 toxin has vascular permeability as well as lethal activities . Both activities are elicited by cooperation of two dissimilar protein components, designated components I and II, which individually have very low activities . The vascular permeability activity of C2 toxin, demonstrated as blueing response after intravenous injection of Evans blue, was markedly enhanced by treatment with trypsin and was abolished by neutralization with either anti-component I or II serum . Inflammatory reactions, such as edema, congestion, and hemorrhage, were found at the site of intradermal injection of trypsinized C2 toxin . No vascular permeability activity was demonstrated by the intradermal injection of the toxin of Clostridium botulinum types A through F . These results indicate that C2 toxin has a novel biological activity, which is not possessed by the neurotoxin elaborated by C . botulinum types A through F . This suggests that C2 toxin causes lethality in a different way from that of botulinum neurotoxin, which is known to inhibit the presynaptic release of acetylcholine at the neuromuscular junction. Appl Environ Microbiol, 1981 Mar, 41(3), 675 - 8 Nature of intracellular type A botulinum neurotoxin; Krysinski EP et al.; The neurotoxin in cells of young Clostridium botulinum type A culture was extracted with lysozyme . Highly purified neurotoxin preparation, obtained by processing the extract in two chromatographic steps had only unnicked (single-chain) molecules of molecular weight comparable to that of the dichains isolated from type A crystals . Trypsinization converted the unnicked molecules into dichains whose component subunits were of sizes indistinguishable from those of the neurotoxin from crystals . The enzymatic treatment increased toxicity of crude extract 30-fold but did not activate the purified intracellular neurotoxin preparation . The results indicated that intracellular type A botulinum neurotoxin is unnicked, is not fully activated, and is activated in the time between its extraction and purification . Since trypsinization nicked all of the single chains without increasing toxicity, nicking was not causally related to toxicity activation. J Lipid Res, 1981 Mar, 22(3), 458 - 66 Formation of urso- and ursodeoxy-cholic acids from primary bile acids by Clostridium absonum; Macdonald IA et al.; Eight strains of Clostridium absonum were shown to form ursocholic acid (UC) from cholic acid (C) and ursodeoxycholic acid (UDC) from chenodeoxycholic acid (CDC) but did not transform deoxycholic acid (DC) in whole cell cultures . The structures of UC and UDC were verified by mass spectroscopy, and by thin-layer chromatography using Komarowsky's spray reagent . The organism transformed C and CDC at concentrations below 1.5 . 10(-3) M and 5.0 . 10(-4) M, respectively; higher concentrations were inhibitory . Optimal yields of the final products were realized at about 15-22 hr and 9-15 hr of incubation, respectively, and were in the range of 60-70% . Additionally, the 7 keto-derivatives, 7 keto-deoxycholic acid (7K-DC) or 7 keto-lithocholic acid (7K-LC) were also formed from C and CDC . With longer periods of incubation, increasing yields of 7K-DC and 7K-LC and decreasing yields of UC and UDC were observed . These time course studies suggest that 7K-DC and 7K-LC are intermediates in the formation of UC and UDC from the primary bile acids . We propose the occurrence of C right harpoon over left harpoon 7K-DC right harpoon over left harpoon UC and CDC right harpoon over left harpoon 7K-LC right harpoon over left harpoon UDC with increasing dominance of back reaction of the second step on aging of the culture . When the initial pH value of the medium was manipulated within the range of 5.8-9.0, increasing yields of UDC from CDC were obtained at higher pH values (maximum yield at pH 9.0 was 83%), with total inhibition of growth and transformation at pH 5.8 . In contrast, UC was produced from C at all pH values studied, with marginal differences in yields (maximum yield at pH 8.0 was 50%) . In all cases, formation of UC from C was much slower than that of UDC from CDC . In contrast, C . paraperfringens transformed none of the above bile acids . We propose that C . absonum, or a biochemically similar species, may be present in the human gut and give rise to UDC (and UC) in vivo.-Macdonald, I . A., D . M . Hutchison, and T . P . Forrest . Formation of urso- and ursodeoxycholic acids from primary acids by Clostridium absonum. Arch Dermatol, 1981 Mar, 117(3), 154 - 5 Pseudomembranous colitis after topical application of clindamycin; Milstone EB et al.; Abdominal cramping and diarrhea developed in a 24-year-old woman with facial acne vulgaris five days after she started topical therapy with 1% clindamycin hydrochloride . A stool specimen contained a significant titer of a toxin produced by Clostridium difficile . Findings from sigmoidoscopy and a colonic biopsy specimen were consistent with pseudomembranous colitis . The patient became asymptomatic after ten days of supportive care and oral vancomycin hydrochloride therapy . This case is presented as an example of pseudomembranous colitis associated with topical application of clindamycin. J Clin Microbiol, 1981 Mar, 13(3), 498 - 502 Optimal fluorescein-to-protein ratios of bacterial direct fluorescent-antibody reagents; Hebert GA et al.; A number of bacterial systems were studied with specific direct fluorescent-antibody reagents prepared from rabbit antiserum fractions and having a wide range of fluorescein-to-protein ratios . These systems included Bacteroides, Bordetella, Clostridium, Escherichia, Legionella, Listeria, Salmonella, Shigella, and Streptococcus . For all systems studied, a fluorescein-to-protein ratio of 30 was optimal for conjugates prepared from ammonium sulfate fractions (greater than 75% gamma globulin) and pure immunoglobulin G desorbed from the Sepharose-bound protein A of Staphylococcus aureus . A pepsin digestion procedure is described that yielded the F(ab')2 piece of pure immunoglobulin G; this was labeled and studied at two fluorescein-to-protein ratios. Biochim Biophys Acta, 1981 Feb 27, 667(2), 433 - 51 Low-temperature magnetic circular dichroism spectra and magnetisation curves of 4Fe clusters in iron-sulphur proteins from Chromatium and Clostridium pasteurianum; Johnson MK et al.; The magnetic circular dichroism (MCD) spectra of the 4Fe clusters in the iron-sulphur proteins high-potential iron protein from Chromatium and the 8Fe ferredoxin from Clostridium pasteurianum have been measured over the wavelength range 300-800 nm at temperatures between approx . 1.5 and 50 K and at magnetic fields up to 5 tesla . In both cases the proteins have been studied in the oxidized and reduced states . The reduced state of high-potential iron protein gives a temperature-independent MCD spectrum up to 20 K, confirming the diamagetism of this state at low temperature . The MCD spectrum of samples of oxidized ferredoxin invariably show the presence of a low concentration of a paramagnetic species, in agreement with the observation that the EPR spectrum always shows a signal at g = 2.01 . The paramagnetic MCD spectrum runs across the whole of the wavelength range studied and therefore most probably originates from an iron-sulphur centre . The diamagnetic component of the MCD spectrum of oxidized ferredoxin is very similar to that of reduced high-potential iron protein . The low-temperature MCD spectra of oxidized high-potential iron protein and reduced ferredoxin reveal intense, temperature-dependent bands . The spectra are highly structured with that of high-potential iron protein showing a large number of electronic transitions across the visible region . The MCD spectra of the two different oxidation levels are quite distinctive and should provide a means of establishing the identity of these state of 4Fe clusters in more complex proteins . MCD magnetisation curves have been constructed from detailed studies of the field and temperature dependence of the MCD spectra of the two paramagnetic oxidation states . These plots can be satisfactorily fitted to the theoretically computed curves for an S = 1/2 ground state with the g factors experimentally determined by EPR spectroscopy . The low-temperature MCD spectra of the reduced 2Fe-2S ferredoxin from Spirulina maxima are also presented and MCD magnetisation curves plotted and fitted to the experimentally determined g factors. J Biol Chem, 1981 Feb 25, 256(4), 1968 - 74 Isolation and structural characterization of human lymphocyte and neutrophil gangliosides; Macher BA et al.; Gangliosides were isolated from purified preparations of human peripheral blood lymphocytes and neutrophils . Structural analyses and comparisons were performed by direct probe mass spectrometry and by degradation studies with the following enzymes: Escherichia freundii endo-beta-galactosidase; Clostridium perfringens and Arthrobacter ureafaciens neuraminidase; and jack bean beta-N-acetylhexosaminidase and beta-galactosidase . This combination of techniques allowed us to obtain carbohydrate composition and sequence information without the aid of methylation or carbohydrate compositional analyses using only 1-2 mg of purified gangliosides . On the basis of these studies we propose that human lymphocytes and neutrophils have gangliosides with the following structures . NeuAc alpha 2 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure A NeuAc alpha 2 leads to ? GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure B NeuAc alpha 2 leads to ? Gal beta 1 leads to 3,4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure C All three compounds were isolated from both cell types with structure A being the major lymphocyte ganglioside and structure C the major neutrophil ganglioside . Structure B is a novel ganglioside and may represent a leukocyte-specific glycosphingolipid . Neuraminidase degradation studies demonstrated that only one ganglioside species of each cell type contains an internally linked sialic acid residue, and on the basis of thin layer chromatographic analysis this component is the same as the major brain ganglioside, GM1 (II3-N-acetylneuraminosyl-gangliotetraosylceramide) . In addition, large gangliosides with the general structure NeuAc alpha 2 leads to ?(Gal beta 1 leads to 3,4GlcNAc beta 1 leads to 3)n Gal beta 1 leads to 4Glc beta 1 leads to 1Cer were isolated . These results are discussed as they relate to blood group antigens and specific cell surface markers in human leukocytes. Biochim Biophys Acta, 1981 Feb 20, 641(1), 138 - 47 Some properties of a new electrogenic transport system: the ammonium (methylammonium) carrier from Clostridium pasteurianum; Kleiner D et al.; Clostridium pasteurianum is able to build up about 100-fold gradients of methylammonium across the cell membrane . Methylammonium enters the cell by means of a carrier as shown by the energy requirement, saturation kinetics and a pH profile with a narrow maximum between pH 6.2 and 6.8 . The methyl ammonium transport (apparent Km = 150 microM, V = 100 mumol/min per g dry weight) is competitively inhibited by ammonium (apparent Ki = 9 microM) . The low Ki value and the observation that methylammonium cannot serve as a carbon or nitrogen source for Cl . pasteurianum strongly indicate that ammonium rather than methylammonium is the natural substrate . Uncouplers and inhibitors of energy metabolism or of the membrane-bound ATPase inhibit transport . Cl . pasteurianum maintains a membrane potential (interior negative) in the range 80-130 mV . This membrane potential was identified as the energy source: the same agents that block transport also decrease the membrane potential, and artificial generation of a membrane potential (by addition of valinomycin to K+-loaded cells) induces concentrative uptake of methylammonium . Thus NH4+ (or CH3NH3+) must be the transported species . Digestion of the cell wall by lysozyme does not abolish the transport activity. Lancet, 1981 Feb 14, 1(8216), 371 - 2 Is pseudomembranous colitis infectious? Greenfield C, Burroughs A, Szawathowski M, Bass N, Noone P, Pounder R. A cluster of eight patients in two adjacent hospital wards acquired acute diarrhoea within a period of 11 days . All their stool samples contained Clostridium difficile toxin and C . difficile was isolated in every case . Three patients had rectal biopsy findings compatible with pseudomembranous colitis (PMC) . All the patients responded to treatment with oral vancomycin . Until the possibility of PMC being acquired by cross-infection is clarified such patients should be nursed in isolation with strict enteric precautions. J Clin Pathol, 1981 Feb, 34(2), 217 - 20 Non-toxigenic clostridia in babies; Mitchell RG et al.; Non-toxigenic clostridia, Clostridium butyricum but occasionally C . paraputrificum, were isolated from mainly extra-alimentary sites of 28 babies in maternity hospital over a period of 40 weeks . During that time, C . butyricum was isolated from the blood of two babies who died of necrotising enterocolitis and of two babies without referable symptoms . Otherwise these organisms appeared to be of no pathogenic significance. Can J Microbiol, 1981 Feb, 27(2), 216 - 25 Growth inhibition activity and bacteriophage and bacteriocinlike particles associated with different species of Clostridium; Nieves BM et al.; Thirty-four strains corresponding to 16 species of Clostridium were examined for growth inhibition activity and production of phage and bacteriocinlike particles . Twenty-five strains were found to inhibit growth of one or more of the other strains . The widest range of activity corresponded to C . bifermentans 18137 which inhibited growth of 23 strains . Cell-free filtrates of positive cultures were inactive with the exception of the one from C . bifermentans 18137 . A wide variety of particles with diverse morphology was observed in lysates of cultures treated with mitomycin C (1 microgram/mL). Appl Environ Microbiol, 1981 Feb, 41(2), 375 - 80 Nisin: a possible alternative or adjunct to nitrite in the preservation of meats; Rayman MK et al.; Nisin at 75 ppm (75 microgram/g) was superior to 150 ppm of nitrite in inhibiting outgrowth of Clostridium sporogenes PA3679 spores in meat slurries, which had been heated to simulate the process used for cooked ham . The inhibitory activity of nisin decreased as the spore load or pH of the slurries increased . Unlike nitrite, inhibition by nisin was unaffected by high levels of iron either as a constituent of meats or when added as an iron salt . In slurries treated with 75 ppm of nisin, refrigerated storage for 56 days resulted in depletion of nisin to a level low enough to allow outgrowth within 3 to 10 days if the slurries were subsequently abused at 35 degrees C . In contrast, a combination of 40 ppm of nitrite and either 75 or 100 ppm of nisin almost completely inhibited outgrowth in these slurries . The nisin-nitrite combination appeared to have a synergistic effect, and the low concentration of nitrite was sufficient to preserve the color in meats similar to that of products cured with 150 ppm of nitrite. Am J Med, 1981 Feb, 70(2), 432 - 8 Bacteria newly recognized as nosocomial pathogens; Fraser DW; Bacteria recently recognized as nosocomial pathogens generally fall into three categories: those that grow slow