Absence of a prosthetic group in a type-specific polysaccharide of pneumococcus

The specific polysaccharide of Type III pneumococcus, with only 0.05 per cent of N and 0.01 per cent of P, still shows almost maximal precipitation of a Type III antipneumococcus rabbit serum and the expected antigenicity in man. There is therefore no evidence that a prosthetic group is involved in these characteristic activities.

Sedimentation and viscosity studies on the capsular and somatic polysaccharides of pneumococcus Type III

Sedimentation constants at infinite dilution have been found to be 1.89 and 4.06 for the somatic and capsular polysaccharides, respectively, from pneumococcus Type III. Intrinsic viscosities have been determined for the somatic and capsular polysaccharides of pneumococcus Type III using the Ostwald viscometer. Molecular weights and dimensions have been calculated for the somatic and capsular polysaccharides of pneumococcus Type III assuming the molecules to be prolate ellipsoids of revolution. Values for the somatic polysaccharide are: molecular weight, 26,400; diameter, 0.97 mµ; and length, 36.18 mµ. Values for the capsular polysaccharide are: molecular weight, 171,800; diameter, 1.04 mµ; and length, 177.87 mµ. The molecular weights were calculated for the somatic and capsular polysaccharides of pneumococcus Type III assuming the molecules to be flexible chains. The value of the molecular weight of the somatic polysaccharide is 31,500 and the value for the molecular weight of the capsular polysaccharide is 267,500. The molecules of both the somatic and capsular polysaccharides exhibit high degrees of asymmetry.

Determination of type in capsulated transformants on pneumococcus by the genome of non-capsulated donor and recipient strains

Capsulated transformants producing type II polysaccharide have been obtained by reactions between a number of R mutants of type II pneumococcus. All the IIR strains except II-R36 yielded extracts which transformed 2 VIIIR strains to VIIIS. Two of the IIR strains were transformed to VIIIS by an extract of 1 VIIIR strain. The most striking result was the production of both IIS and VIIIS transformants by the action of extracts of both VIIIR strains applied to cells of II-RB. This suggests that the determination of capsular type in pneumococcus does not depend on single allelomorphic genes; it seems more likely that a number of genes may be required to determine type specificity, and that some genes may be common to different types, possibly in connection with common biochemical pathways for some stages of polysaccharide synthesis. This is further indicated by the finding that extracts of capsulated strains of each of the types I, II, III, VII, VIII, XIV, and XVIII are capable of giving IIS transformants with 1 or more of the IIR strains in addition to the expected donor-type transformants. Strain II-R36 was transformed by extracts of all S types except type VII, but the only transformants found were of the donor type. It appears that II-R36 may have multiple genetic deficiencies for type II capsulation, possibly in the form of a deletion. This may be the case also with IIIS strains since only IIIS transformants were found when IIIS extract was applied to any of the IIR strains.

In vitro effects of C-reactive protein on phagocytosis

Hokama, Y. (University of California, Los Angeles), Monroe K. Coleman, and Richard F. Riley. In vitro effects of C-reactive protein on phagocytosis. J. Bacteriol. 83:1017-1024. 1962. Carbonyl iron spherules, Diplococcus pneumoniae types IIs and XXVIIs, and Serratia marcescens were phagocytosed more rapidly and in greater numbers by leukocytes of normal human blood after incubation with C-reactive protein. With the exception of carbonyl iron spherules, addition of C-reactive protein to whole blood containing substrate had little effect on the extent of phagocytosis. Normal and acute-phase seromucoid Escherichia coli lipopolysaccharide and crude endogenous pyrogen were without a stimulating effect under the same conditions in the homologous systems employed.

Release of genetic transforming agent from pneumococcal cultures during growth and disintegration

Genetic transformations of pneumococcus mediated by streptomycin-induced lysates were studied to gain some insight into the nature of freshly released transforming principle, and the influence of the physiologic state of the donor population on the transformation process. It was found that streptomycin could make the DNA of sensitive cells available for transformation of other cells. Living cultures of pneumococcus growing exponentially in ordinary media were also found to discharge significant quantities of genetically active DNA. Such cultures, not treated with any drug, showed no evidence of concomitant cell disintegration or death. Both single markers and small linkage groups could be transferred in transformations mediated by drug-induced lysates and by filtrates of living cultures. The quantity of DNA liberated is small (less than 0.1 µg per ml), but these transformations are at least as efficient as transformations mediated by purified DNA, when compared on the basis of total DNA available. Up to 1 per cent of the cells in an average recipient culture can be transformed by a small quantity of culture fluid. Both in drug-treated and in untreated cultures the amount of transforming activity increased and then decreased during growth of the culture. Although the source of transforming DNA in growing cultures could not be established, the decline in the transforming activity of aging drug-treated or untreated cultures was attributed to the presence of deoxyribonuclease. The release of this nuclease by pneumococcal cultures midway in exponential growth is sufficient to result in a mild degradation of the low concentration of freshly released transforming agent present. Maximal release of active transforming agent by a living culture coincided in time with the development of maximal receptivity to exogenous DNA by that culture. As a result, recombinants could be recovered from appropriately genetically marked strains growing in each other's presence. In view of these results, it seems possible that DNA-mediated transformations might provide, or might have provided, a mechanism of genetic recombination in nature for some bacterial species in which sexual mechanisms may not be available.

Effect of manganese and enzymatic deoxyribonucleic acid digests on population changes and respiration of Pneumococci

Firshein, William (Wesleyan University, Middletown, Conn.). Effect of manganese and enzymatic deoxyribonucleic acid digests on population changes and respiration of pneumococci. J. Bacteriol. 84:478-484. 1962.-Deoxyribonucleic acid (DNA; Na salt) treated with deoxyribonuclease and Mn(++) (as MnSO(4)) stimulated R (avirulent) to S (virulent) population changes in vitro. Under certain environmental conditions and with certain strains, Mn(++) alone elicited these changes, but, in most cases, both digested DNA and Mn(++) were necessary for maximal effect. These population changes were due to a selective stimulation of the multiplication of S cells and a delay in S-cell lysis, with either a slight inhibitory effect or no effect against the multiplication of R cells. The magnitude of the population change depended upon the presence of digested DNA, the level of Mn(++), the strain, and the concentration of basal medium. Mn(++) enhanced respiration of S cells while inhibiting that of R cells.

INFLUENCE OF DEOXYRIBONUCLEIC ACID DEGRADATION PRODUCTS AND ORTHOPHOSPHATE ON DEOXYNUCLEOTIDE KINASE ACTIVITY AND DEOXYRIBONUCLEIC ACID SYNTHESIS IN PNEUMOCOCCUS TYPE 3

Firshein, William (Wesleyan University, Middletown, Conn.). Influence of deoxyribonucleic acid degradation products and orthophosphate on deoxynucleotide kinase activity and deoxyribonucleic acid synthesis in pneumococcus type III. J. Bacteriol. 90:327-336. 1965.-An oligodeoxynucleotide fraction derived from a deoxyribonuclease-treated calf-thymus deoxyribonucleic acid (DNA) can enhance the activity of deoxycytidylic acid (dCMP) and deoxyguanylic acid (dGMP) kinases in cell suspensions of type III pneumococci. High levels of orthophosphate can produce similar effects. For part of the incubation period, the activity of dCMP and dGMP kinases is very low or undetectable in unsupplemented-cell suspensions of pneumococci. In contrast, the remaining kinases, deoxyadenylic acid and thymidylic acid, which are present in ample amounts in control and supplemented cells throughout the incubation period, are unaffected by the addition of oligodeoxynucleotides and orthophosphate. The stimulation of kinase activity is amino acid-dependent and can be abolished by adding chloramphenicol. When the oligodeoxynucleotide fraction and orthophosphate are further supplemented with all eight of the naturally occurring deoxynucleosides and deoxynucleotides (which do not affect kinase activity), a preferential enhancement of DNA synthesis occurs in comparison with cell growth or protein synthesis. Addition of deoxynucleosides and deoxynucleotides to unsupplemented cells produces only a slight increase in DNA synthesis. The preferential enhancement of DNA synthesis can be prevented by adding chloramphenicol at a certain time during incubation.

GENETIC LINKAGE OF MUTATIONAL SITES AFFECTING SIMILAR CHARACTERS IN PNEUMOCOCCUS AND STREPTOCOCCUS

Ravin, Arnold W. (University of Rochester, Rochester, N.Y.), and Joscelyn D. H. De Sa. Genetic linkage of mutational sites affecting similar characters in pneumococcus and streptococcus. J. Bacteriol. 87:86-96. 1964.-By interspecific transformation, deoxyribonucleic acid (DNA) determinants conferring resistance to high levels of streptomycin in pneumococcus were found to be allelic with DNA determinants conferring low levels of streptomycin resistance in the Challis and NBSI strains of streptococcus. The reciprocal transformation (low resistance pneumococcus x high resistance streptococcus) led to the same conclusion. In addition, determinants controlling resistance to erythromycin in pneumococcus and the Challis strain of streptococcus were found to become closely linked after interspecific transformation. Modifier genes influencing the phenotype conferred by mutations at the streptomycin-resistance locus differentiate species to a certain extent. The results demonstrate that transformations between pneumococcus and streptococcus are not due to episomes, but involve recombinational events in which genetic material of the host species is replaced by homologous material that performed a similar function in the donor species.

INHIBITION OF BACTERIAL GROWTH BY DRUGS OF THE MORPHINE SERIES

The growth of Escherichia coli is reversibly inhibited by drugs of the morphine series. The order of inhibitory effectiveness for the drugs tested was levallorphan > levorphanol > dextrorphan > nalorphine > morphine. The synthetic analgesic, levorphanol, was studied in greater detail. Its effectiveness was found to be strongly dependent on the pH of the medium. Raising the pH of the medium provides a higher concentration of the neutral free base which is thought to diffuse across cell membranes more readily. However, considerations other than the rate of entry of drug into the cells must be of importance since an already established growth inhibition is promptly reversed upon lowering the pH of the medium. Two mutants of Escherichia coli with altered sensitivity to levorphanol were isolated.

THE FINE STRUCTURE OF DIPLOCOCCUS PNEUMONIAE

The fine structure of an unencapsulated strain of Diplococcus pneumoniae is described. A striking feature of these bacteria is an intracytoplasmic membrane system which appears to be an extension of septa of dividing bacteria. The possible function of these structures and their relationship to the plasma membrane and other types of intracytoplasmic membranes found in pneumococcus is discussed.

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.

GAMMA GLOBULIN TURNOVER IN RABBITS BEFORE AND DURING HYPERIMMUNIZATION

The turnover of ¹³¹I-labeled gamma globulin has been determined in rabbits before and during (8 weeks later) hyperimmunization with pneumococcic vaccine, which increased the gamma globulin concentration 5 to 10 times. Before immunization fractional turnover rate was an average of 36 per cent of the plasma pool per day, and the rate of catabolism was 133 mg/kg/day. During hyperimmunization fractional turnover rate was an average of 37 per cent per day, and the rate of catabolism was 1160 mg/kg/day. The observation that the fractional turnover rate is independent of the concentration suggests that the rate of breakdown should have the characteristic of a first order process.

IN VITRO BIOLOGICAL ACTIVITY OF CEPHALOTHIN

Chang, Te-Wen (Tufts University School of Medicine, Boston, Mass.) and Louis Weinstein. In vitro biological activity of cephalothin. J. Bacteriol. 85:1022-1027. 1963.-Cephalothin is a "broad-spectrum" antibiotic active, in low concentrations, against Diplococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus. Shigella, Salmonella, and Proteus mirabilis were the most sensitive of the gram-negative organisms. Escherichia coli and Aerobacter aerogenes were suppressed to a lesser degree, whereas Pseudomonas aeruginosa and Herellea were highly resistant. Penicillin-sensitive and -resistant strains of S. aureus were equally susceptible to cephalothin. Exposure to increasing concentrations of the drug very frequently led to the development of resistance in gram-negative organisms; this was observed less often with S. aureus. Cephalothin stimulated the production of penicillinase by staphylococci, which remained sensitive to the cephalosporanic acid derivatives despite repeated subculture in increasing concentrations of the agent. Cephalothin was not inhibited by penicillinase. This antibiotic was more toxic to cultures of human amnion and mouse embryo cells than benzyl penicillin G but was less injurious than oxytetracycline, chlortetracycline, and demethylchlortetracycline; tetracylcine produced about the same degree of cellular damage as cephalothin.

STUDIES ON THE PATHOGENESIS OF FEVER. 13. THE EFFECT OF PHAGOCYTOSIS ON THE RELEASE OF ENDOGENOUS PYROGEN BY POLYMORPHONUCLEAR LEUKOCYTES

1. Phagocytosis promotes the release of endogenous pyrogen from polymorphonuclear leucocytes. 2. The release of pyrogen, though initiated by the phagocytic event, is not synchronous with it. 3. The postphagocytic release mechanism is not inhibited by sodium fluoride and, therefore, appears not to require continued production of energy by the cell. 4. The release process, on the other hand, is inhibited by arsenite, suggesting the participation of one or more sulfhydryl-dependent enzymes in the over-all reaction. 5. Particle for particle, the ingestion of heat-killed rough pneumococci causes the release of approximately 100 times as much pyrogen as the ingestion of polystyrene beads of the same size. 6. The pyrogen release mechanism of polymorphonuclear leucocytes separated directly from blood, unlike that of granulocytes in acute inflammatory exudates, is not readily activated by incubation of the cells in K-free saline. Despite this difference, both blood and exudate leucocytes following phagocytosis release large amounts of pyrogen, even in the presence of K(+). The fact that the postphagocytic reaction is uninhibited by the concentrations of K(+) which are present in plasma and extracellular fluids, suggests that this mechanism of pyrogen release may well operate in vivo. 7. As might be expected from the foregoing observations, the intravenous injection of a sufficiently large number of heat-killed pneumococci causes fever in the intact host. Intravenously injected polystyrene beads, on the other hand, are significantly less pyrogenic. Evidence is presented to support the conclusion that the fever in both instances is caused by pyrogen released from the circulating leucocytes which have phagocyted the injected particles. 8. The possible relationships of these findings to the pathogenesis of fevers caused by acute bacterial infections are discussed.

STUDIES ON THE RELATIONSHIP OF ALLOTYPIC SPECIFICITIES TO ANTIBODY SPECIFICITIES IN THE RABBIT

Purified antibodies against three different antigens and haptens (ovalbumin, dinitrophenol, and Type II pneumococcal polysaccharide) were prepared from specific precipitates from the antisera of several rabbits. The reactions of these preparations with antisera against the allotypic specificities carried by each of the animals forming the antibodies were used to compare the relative concentrations of molecules bearing each specificity in the different solutions of antibodies from each rabbit. These relative concentrations appeared to vary greatly from one preparation to another, although all the allotypic specificities carried by each animal were found in all the preparations of antibodies from that animal. The interpretation of these results is discussed.

CROSS-REACTIONS OF PNEUMOCOCCAL TYPES. QUANTITATIVE STUDIES WITH THE CAPSULAR POLYSACCHARIDES

Data are given on the amounts of antibody nitrogen precipitated in the crossreactions, often reciprocal, of the specific capsular polysaccharides of the pneumococcal type pairs II and XX, II and XIX, VII and XIV, VII and XVIII, VII and XIX, VIII and XVIII, VIII and XIX, X and XIV, and X and XX. Since little is known of the fine structures of the polysaccharides of Types VII, X, XIX, and XX, rigorous correlations between chemical structure and specificity can not be made, but several tentative conclusions are drawn.

ALTERATION IN TRANSFORMABILITY OF DIPLOCOCCUS PNEUMONIAE AFTER THE ACQUISITION OF GENETIC DETERMINANTS INDUCING RESISTANCE TO ERYTHROMYCIN

Sirotnak, Francis M. (Sloan-Kettering Institute for Cancer Research, New York, N.Y.), Ramona B. Lunt, and Dorris J. Hutchison. Alteration in transformability of Diplococcus pneumoniae after the acquisition of genetic determinants inducing resistance to erythromycin. J. Bacteriol. 86:735-739. 1963.-The genetic alteration of a highly transformable (competent) recipient strain of Diplococcus pneumoniae by the transformation of at least two of three identified erythromycin-resistance determinants (Ery(a), Ery(b), Ery(c)) results in a marked decrease (Ery(a-b) recombinant) or complete loss (Ery(a-c) recombinant) in the ability to be transformed. The occurrence of transformable cells in cultures of the R6 Ery(a-b) recombinant strains, although greatly diminished, still varies during growth in a manner characteristic of the fully competent parent strain. Both Ery(b) and Ery(c) determinants appear to be linked to Ery(a). In experiments using P(32)-labeled deoxyribonucleic acid (DNA), data correlating DNA uptake with transformation show a decrease or loss in uptake capacity of the erythromycin-resistant strains.

GAMMA GLOBULIN METABOLISM IN RABBITS DURING THE ANAMNESTIC RESPONSE

1. Gamma globulin metabolism and distribution were studied employing rabbit gamma globulin (RGG)I¹³¹ 24 times in 13 control rabbits. Similar studies were performed before and during the ananmestic response in 4 rabbits previously sensitized with a polyvalent pneumococcal vaccine. 2. During the ananmestic response, gamma-globulin levels increased from 1.0 to 6.0 gm/100 ml, and the gamma-globulin pool increased from 0.7 to 4.7 gm/kg. There was no change in the intravascular-extravascular partition of gamma globulin. 3. Gamma globulin degradation increased from 0.06 to 0.33 gm/kg/day during the 28 days of the immunization period while gamma globulin synthesis increased even further to average 0.47 gm/kg/day. Following the attainment of elevated gamma globulin levels the fractional rate of RGG-I¹³¹ turnover increased from 8.0 to 12.5 per cent/day. 4. No differences were noted in the metabolism of homologous or autologous gamma globulin regardless of the allotypic specificities.