摘要:

As part of an epidemiologic study on unclassified mycobacterial infection in Houston, Texas, soil samples were collected from the home environment of elementary school students with a positive skin test to PPD-B (group III antigen) and examined for the presence of mycobacteria.Mycobacteria (101 strains) were isolated from 77 of 92 soil samples. Of 93 strains studied, 57 resembled knownMycobacteriumspecies as follows: 48,M.fortuitum; 5,M.smegmatis, and 4,M.peregrinum. If distributed among the four groups of "unclassified mycobacteria", none appeared in group I; 5 in group II; 3 in group III; and 85 in group IV.

ISSN:0008-4166    

DOI:10.1139/m65-018

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

not available

ISSN:0008-4166    

DOI:10.1139/m65-019

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The effect of relative humidity (R.H.) and inositol on the capacity of semidried cells ofE.coliB to manufacture five bacteriophages, together with the effect of drying on the vegetative phages of infected cells, has been studied. Also, the action of drying and inositol on the induction of lysis and production of lambda phage byE.coliK12 has been examined. It was found that the bound-water content of a cell determined the response of all phenomena to drying. As the R.H. was lowered from 70%, where the bound-water content is approximately 25 g/100 g cell solids, to 40% (10 g/100 g cell solids) a rapid decline in the resistance of both the capacity and vegetative phage occurred. In addition, the extent of vegetative phage inactivation was found to depend on the time after infection and prior to drying. All vegetative phages showed their maximum sensitivity immediately and up to 7 minutes after infection, then their sensitivity decreased and maximal stability occurred 15 minutes after infection. Inositol completely prevented capacity or vegetative phage inactivation under the conditions described. Desiccation was found to induce the lysis ofE.coliK12 and the production of lambda phage. In terms of the percentage of viable cells lysed a greater proportion of the cells surviving desiccation at 30% R.H. was found to undergo lysis than those desiccated at 70% R.H., or at all R.H. levels in the presence of inositol.

ISSN:0008-4166    

DOI:10.1139/m65-020

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Data are presented which demonstrate that dogs and mice produce immuno-conglutinin in response to a variety of bacterial infections. The production of immuno-conglutinin was stimulated by infections with five Gram-negative and six Gram-positive species of bacteria. The greater the challenge dose of organisms the greater was the immuno-conglutinin response, and challenges of immunized animals stimulated greater responses than challenges of non-immunized animals. Virulent strains or species stimulated a greater immuno-conglutinin response than did non-virulent organisms of similar strains or species.These experiments show that the production of immuno-conglutinin is one of the serological responses which are characteristic of acute bacterial infections.

ISSN:0008-4166    

DOI:10.1139/m65-021

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

In mice chronically infected withBrucella abortusorSalmonella typhimuriumthe production of immuno-conglutinin was stimulated and the serum levels of conglutinating activity remained elevated over a prolonged period, probably throughout the infection. Infection withMycobacterium tuberculosiscaused a slow rise in immuno-conglutinin titers in rabbits. In limited infections the peak titer was followed by a decreasing level of activity. In active and progressive infections the immuno-conglutinin titer was maintained at a high level.These experiments show that the production of immuno-conglutinin is one of the serological responses which are characteristic of chronic bacterial infections and that high levels of conglutinating activity are maintained for prolonged periods during such infection.

ISSN:0008-4166    

DOI:10.1139/m65-022

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

β-1,4-Mannanases are of common occurrence in fungi. They are induced enzymes, the yields of enzyme being 10- to 100-fold greater when the organism is grown on mannan. All of the β-mannanases studied are endopolysaccharases acting on long chains in a random manner and unable to act on mannotriose or mannobiose. Acting on substituted mannans, they yield products containing the branch. Most of the microbial mannanase preparations contain glycosidases capable of removing galactose or glucose units from the mannan chain. The few which lack glycosidases are useful in the production of oligosaccharide products.

ISSN:0008-4166    

DOI:10.1139/m65-023

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Mutants ofEscherichia coliB selected on the basis of resistance to nitrofurazone, NFT, or ultraviolet light proved to be resistant to all three of these agents. Further tests showed that these mutants are also resistant to three other nitrofuran derivatives, nitrofurantoin, nihydrazone, and furazolidone, but not to nifuroxime. The mutants are also resistant to the chemically dissimilar radiomimetic agent, proflavin. Strain B and all the mutants derived from it are equally sensitive to streptomycin, a non-radiomimetic antibiotic.E.colistrain B/r (resistant to radiation and radiomimetic chemicals) shows the same resistance pattern as the new mutant strains. The results are discussed in terms of what is known concerning the basis for the resistance of strain B/r to ultraviolet light. It is concluded that radiomimetic nitrofurans probably exert their effect onE.colithrough damage to DNA.

ISSN:0008-4166    

DOI:10.1139/m65-024

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

It was shown thatPseudomonas aeruginosastrain 64 was extensively Iysed by EDTA alone and that destruction of cells was as complete as when lysozyme was used in combination with EDTA as evidenced by microscopic examinations and viability tests of the bacterial suspensions. Lysozyme alone caused no appreciable lysis. Lysozyme was not completely without effect. Cells that were preincubated with lysozyme, washed, and resuspended in the presence of EDTA lysed at the same rate and to the same extent as in a system containing both EDTA and lysozyme. Electron microscopy revealed that, after incubation with lysozyme, cells showed altered physical appearances manifested by "ballooning" and bulging of the cell walls. Incubation of cells with rhodamine-labelled lysozyme indicated that lysozyme is bound to the cellular surface and that it is readily removed by washing.There is evidence that EDTA acts through its chelation properties. Calcium was chelated in greatest quantity. EDTA was replaceable by structurally related polyacetic acid chelating agents but not by other chelating agents or by detergents. It is concluded that the binding of divalent metals, which may function to form cross-linkages, is essential for the integrity of the cell walls ofP.aeruginosa.

ISSN:0008-4166    

DOI:10.1139/m65-025

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Partially purified preparations of delta hemolysin demonstrated growth-inhibitory activity against certain Gram-positive bacteria, including certain strains ofStaphylococcus aureus. Primary and replica plate assays indicated that the pattern of antibacterial activity manifested against a typical strain, highly sensitive to delta hemolysin, was that given by a typical antibiotic. Bactericidal, bacteriostatic, and stimulation zones were seen, dependent upon the lysin concentration. Certain of the delta hemolysin-producing strains ofS.aureusmanifested a pattern of growth inhibition wherein particular members of the cultures responded by bacteriostasis to high concentrations of lysin, while the remaining organisms showed no overt growth inhibition. Other strains of delta hemolysin-producingS.aureuswere not inhibited in growth by delta hemolysin preparations.The identity of the delta hemolysins and the antibiotic material has not been established. However, analysis by paper chromatography of delta hemolysin preparations revealed at least two hemolytic substances, delta A and delta B, manifesting hemolysis of human erythrocytes and associated with antibiotic activity.

ISSN:0008-4166    

DOI:10.1139/m65-026

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

A survey of 75 cultures ofPseudomonas aeruginosacontaining only one discernible phenotype indicated that 68 routinely exhibited spontaneous lysis, resulting in the appearance of turbid erosions or autoplaques (AP+) when grown on a tryptone–glucose agar medium. Single supplements of non-inhibitory levels of chloromycetin, aureomycin, tetracycline, declomycin, and streptomycin increased the degree of lysis of AP+strains, but were without effect on AP−strains. Enhancement of lysis was also obtained with sulfadiazine, sulfathiazole, sulfamethoxypyridazine, elkosin, gantrisin, and triple sulfa, while little or no effect was observed with sulfamerizine and thiosulfil. On the other hand, low concentrations of either acriflavine or proflavine retarded the rate and degree of lysis, while single supplements of the active antibiotics overcame the suppressive effects of the dyes.

ISSN:0008-4166    

DOI:10.1139/m65-027

出版商:NRC Research Press    

年代:1965

数据来源: NRC