Versatile medium for the enumeration of sulfate-reducing bacteria

A lactate-yeast extract-sulfate medium, making use of both thioglycolate and ascorbate to poise the E(n) gave valid colony counts of sulfate-reducing bacteria with both pure cultures and natural samples.

POLYVINYL-PYRROLIDONE-IODINE: AN ASSESSMENT OF ANTIBACTERIAL ACTIVITY

Polyvinyl-pyrrolidone-iodine complex (PVP-I) was shown to have a rapid disinfectant activityin vitroagainst vegetative bacteria and fungi and against vegetativeTrichomonas. The presence of organic matter had a slight delaying effect on the killing time. Bacterial spores survived in PVP-I for 17 hr. and fungal spores for 1½ hr. Used as an agent for pre-operative preparation of the skin, PVP-I was more efficient than others tested, rendering the skin surface sterile even when heavily contaminated, and keeping it so for 1 hr. None of the staining characteristics of iodine were noted since PVP-I was easily removed by water. Two individuals, known to be iodine sensitive, developed mild iodism after application of PVP-I.

The authors are indebted to the staff of the hospital for their co-operation; and to Berk Pharmaceuticals Limited for supplies of PVP-I, manufactured by them as Betadine (Povidone-iodine B.P.).

KINETICS OF DRY RUPTURE OF BACTERIAL SPORES IN THE PRESENCE OF SALT

Sacks, L. E. (U.S. Department of Agriculture, Albany, Calif.), Peter B. Percell, Richard S. Thomas, and Glen F. Bailey. Kinetics of dry rupture of bacterial spores in the presence of salt. J. Bacteriol. 87:952-960. 1964.-The kinetics of breaking spores in the dry state by use of an excess of sodium chloride and a steel ball in a shaking device were investigated. Under most conditions, disruption is a first-order process. The disruption-rate constant varies directly with the weight of the ball and inversely with the weight of the capsule contents (spores plus salt). Different spore batches differ somewhat in susceptibility to dry rupture. The dry-rupture process is highly reproducible and it is relatively simple to obtain preparations in which exactly 50%, or 90%, of the spores are broken. The procedure is uniquely suited to the disruption of small (5 to 20 mg) samples, but 150 mg of spores have been handled with conventional equipment. Apparently, the chief function of the salt is to separate the spores from one another with a relatively hard, energy-nonabsorbing matrix, preventing aggregation and consequent cushioning of the ball's impact. However, under certain conditions (small ball, high salt, large crystals) appreciable breakage results from collisions of spores with the salt crystals. The minimal salt-spore ratio for efficient breakage depends on the spore batch, but is usually greater than 3:1. Fine glass beads or inorganic salts other than sodium chloride will also serve as the matrix. Electron micrographs of the spores in various stages of disruption are shown, as are electron micrographs of the spore coats of Bacillus macerans, B. megaterium, B. cereus, B. coagulans, and Clostridium bifermentans. Prolonged agitation disintegrates spore coats. The spore coats of B. macerans exhibit a characteristic ribbed structure, previously detected only by carbon replicas of intact spores. Possible application to other biological materials is considered.

TAXONOMY OF CLOSTRIDIUM BIFERMENTANS AND CLOSTRIDIUM SORDELLII. I. THEIR TOXIGENICITY, UREASE ACTIVITY, AND SPORULATING POTENCY

Nishida, S. (Kanazawa University, Kanazawa, Japan), K. Tamai, and T. Yamagishi. Taxonomy of Clostridium bifermentans and Clostridium sordellii. I. Their toxigenicity, urease activity, and sporulating potency. J. Bacteriol. 88:1641-1646. 1964.-Strains with properties similar to those of Clostridium bifermentans were usually obtained by selecting heat-resistant substrains of C. sordellii 1734. Heat-resistant substrains obtained from seven other strains were also found to be nontoxic. Some of these heat-resistant substrains produced urease, but others did not. Substrains of typical cultures of C. sordellii thus can yield either substrains resembling nonpathogenic strains of C. sordellii culturally, or substrains resembling C. bifermentans. The sporulating potency of pathogenic and nonpathogenic strains of C. sordellii and strains of C. bifermentans proved to be significantly distinct. The sporulating potency of C. bifermentans was high, that of pathogenic strains of C. sordellii was low, and that of nonpathogenic strains of C. sordellii was intermediate between the other two.

ISOLATION OF OBLIGATELY ANAEROBIC PSYCHROPHILIC BACTERIA

Sinclair, N. A. (Washington State University, Pullman), and J. L. Stokes. Isolation of obligately anaerobic psychrophilic bacteria. J. Bacteriol. 87:562-565. 1964.-A total of 11 strains of strictly anaerobic psychrophilic bacteria have been isolated from soil, mud, and sewage. The organisms grow well at 0 C in liquid and on solid media, and grow only in the complete absence of oxygen. On the basis of shape, sporulation, flagellation, and strictly anaerobic growth, all of the organisms were classified as strains of Clostridium. Some of the biochemical properties of the strains and the effect of temperature on growth are described.

TAXONOMY OF CLOSTRIDIUM BIFERMENTANS AND CLOSTRIDIUM SORDELLII. II. TOXIGENIC AND SPORULATING POTENCIES IN SUBSTRAINS OF A CLOSTRIDIUM SORDELLII STRAIN

Tamai, Kenzo (Kanazawa University, Kanazawa, Japan), and Shoki Nishida. Taxonomy of Clostridium bifermentans and Clostridium sordellii. II. Toxigenic and sporulating potencies in substrains of a Clostridium sordellii strain. J. Bacteriol. 88:1647-1651. 1964.-The existence of six biological criteria for distinction of Clostridium bifermentans and C. sordellii was confirmed. The difference in the six criteria gradually disappeared as the sporulating potency of the substrains of C. sordellii 4708 was strengthened. The substrains which could resist heating at 90 C for 10, 20, or 30 min were found to have lost all six criteria for distinction and were biologically in agreement with C. bifermentans. We further demonstrated that all newly isolated strains of C. bifermentans examined possessed extremely strong sporulating potency.

BACTERIAL NUCLEOTIDASES

Kohn, J. (Queen Mary's Hospital, London, England) and J. L. Reis. Bacterial nucleotidases. J. Bacteriol. 86:713-716. 1963.-The 3- and 5- nucleotidase activity in various bacterial species was investigated. Both enzymes were found in bacterial extracts in varying proportions. The nucleotidases were found to be very active in Proteus vulgaris, in which organism they were studied in detail. The relative activities, the pH optima, and the effect of metal ions were investigated. It was concluded that bacterial 3- and 5-nucleotidases are distinct and separate enzymes.

SURVEY OF THE BACTERIOCINES OF ENTEROCOCCI

Brock, Thomas D. (Indiana University, Bloomington), Barbara Peacher, and Deborah Pierson. A survey of the bacteriocines of enterococci. J. Bacteriol. 86:702-707. 1963.-A survey has been made of bacteriocine production by a wide variety of well-characterized strains of group D streptococci. On the basis of spectrums and sensitivity to chloroform, heat, and proteolytic enzymes, five distinct bacteriocines can be defined. Type 1 is produced by all Streptococcus zymogenes (S. faecalis var. zymogenes) strains, is active against a wide variety of gram-positive bacteria, and is also a hemolysin. Type 2 is produced by some S. liquefaciens (S. faecalis var. liquefaciens) strains, and acts on many enterococci as well as on certain other lactic acid bacteria. Type 3 is produced by certain strains of both S. faecalis and S. faecium, and inhibits a wide variety of group D streptococci, but is inactive against all other lactic acid bacteria tested except Leuconostoc citrovorum. Type 4 is produced by certain S. faecium strains and resembles in certain ways the type 3 activity, but differs from it in other ways. Type 5 has been found to be produced by only one proteolytic strain of S. zymogenes, and this bacteriocine has a very narrow spectrum. The strain that produces this bacteriocine also produces type 1 activity. No strain is sensitive to a bacteriocine of the type it produces.

SEROLOGICAL GROUPING OF THE PATHOGENIC CLOSTRIDIA

Ellner, Paul D. (University of Vermont, Burlington), and Stanley S. Green. Serological grouping of the pathogenic clostridia. J. Bacteriol. 86:1098-1100. 1963.-By use of the soluble antigens of ten species of pathogenic clostridia and specific globulins, it has been possible to divide these organisms into a number of groups based upon the presence or absence of precipitin lines in agar gel. A scheme for such a grouping is presented, and the utility of this method is discussed.

IDENTIFICATION OF COLEMAN'S SULFATE-REDUCING BACTERIUM AS A MESOPHILIC RELATIVE OF CLOSTRIDIUM NIGRIFICANS

Postgate, John R. (University of Illinois, Urbana) and L. Leon Campbell. Identification of Coleman's sulfate-reducing bacterium as a mesophilic relative of Clostridium nigrificans. J. Bacteriol. 86:274-279. 1963.-Coleman's sulfate-reducing bacterium is immunologically and morphologically similar to Clostridium nigrificans and unlike Desulfovibrio species. It is not thermophilic and does not acquire the thermophilic habit; it is thus the first naturally occurring mesophilic member of this group to be described.

THE ACTION OF ENZYMES FROM CLOSTRIDIUM TERTIUM ON THE I ANTIGENIC DETERMINANT OF HUMAN ERYTHROCYTES

A method was described for the partial purification of beta galactosidase and beta glucosaminidase from Clostridium tertium culture supernatants. Treatment of erythrocytes with preparations containing both enzymes decreases their ability to react with anti-I cold agglutinins, and with Type XIV antipneumococcal horse serum. Erythrocytes of blood group A₁ are altered more rapidly and extensively than are group O cells. The enzymatic treatment of stroma results in a decrease in ability to absorb anti-I agglutinins and the release of galactose and N-acetylglucosamine as monosaccharides. The data suggest that these two sugars may be structural units of the erythrocyte I determinant, but no direct evidence is available.

ULTRAVIOLET-ABSORPTION SPECTRA OF DRY BACTERIAL SPORES

Bailey, Glen F. (Western Regional Research Laboratory, Albany, Calif.), Saima Karp, and L. E. Sacks. Ultraviolet-absorption spectra of dry bacterial spores. J. Bacteriol. 89:984-987. 1965.-The possibility of obtaining reasonably satisfactory ultraviolet-absorption spectra of dry spores embedded in KBr has been demonstrated. Such spectra show the three peaks characteristic of calcium dipicolinate. The dipicolinate spectra are more distinct when reference pellets containing appropriate amounts of the analogous spore coats are employed. These spectra are considered evidence that some type of calcium-dipicolinic acid chelate accounts for at least part of the calcium and dipicolinic acid content of the spore.

RELATIONSHIP BETWEEN TOXIGENICITY AND SPORULATING POTENCY OF CLOSTRIDIUM NOVYI

Nishida, Shoki (Kanazawa University, Kanazawa, Japan), and Gizo Nakagawara. Relationship between toxigenicity and sporulating potency of Clostridium novyi. J. Bacteriol. 89:993-995. 1965.-The less toxigenic the strains, the stronger was the sporulating potency of Clostridium novyi strains isolated. This was confirmed by investigation of the toxigenicity of substrains of C. novyi 140 possessing different degrees of sporulating potency. Atoxic strains or type C strains could be obtained from the parent type A strain (no. 140) by heat selection. This phenomenon was also observed in the other five strains. Prolonged storage of C. novyi strains also resulted in selection of cells with stronger sporulating ability and lower toxigenicity.

RAPID TECHNIQUE FOR THE ENUMERATION OF CLOSTRIDIUM PERFINGENS

A new medium, Tryptone-sulfite-neomycin (TSN) agar, and an incubation procedure for the enumeration of Clostridium perfringens are described. Tolerance to neomycin, optimal growth at 46 C, and sulfite-reducing properties of C. perfringens were used as a basis for development of the medium. Comparisons were made between sulfite-polymyxin-sulfadiazine (SPS) agar and TSN agar at 37 and 46 C with C. perfringens and other organisms. These studies indicate the quantitative and selective superiority of TSN agar, incubated at 46 C, over SPS agar.

CLOSTRIDIUM RUBRUM SP. N. AND OTHER PECTINOLYTIC CLOSTRIDIA FROM SOIL

Ng, Henry (University of California, Davis) and Reese H. Vaughn. Clostridium rubrum sp. n. and other pectinolytic clostridia from soil. J. Bacteriol. 85:1104-1113. 1963.-Reports in the literature and results of experiments described herein suggest that pectinolytic anaerobes constitute a very heterogeneous group. The cultures isolated in this study all belonged to the genus Clostridium. The following species were identified: C. butyricum, C. fallax, C. multifermentans, and C. indolis. In addition, a species believed to be previously undescribed was named C. rubrum sp. n. The ability to ferment galacturonic acid was found to be adaptive. Some cultures fermented pectin and pectic acid to the same degree, whereas others fermented pectin only partially. The partial fermentation was attributed to the lack of a pectinesterase. On the basis of fermentation balances, it was concluded that the four strains of galacturonic acid fermenters selected for study yielded identical end products in approximately the same proportions. Per mole of galacturonic acid fermented, about 2 moles of CO(2), 1.5 moles of H(2), 1.5 moles of acetic acid, and 0.25 mole of butyric acid were produced.