Effect of Bactericidal Substance from Staphylococcus aureus on Group A Streptococci II. Structural Alterations (original) (raw)
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Infection and immunity, 1970
A bactericidal substance isolated from phage type 71 staphylococci has been studied relative to its mechanism of action on streptococcal cells. The substance exerts its effect best at 37 C. No cell lysis occurs as evidenced by lack of alteration in optical density of susceptible cell suspensions. The bactericidal substance results in immediate cessation of protein and deoxyribonucleic acid synthesis as well as degradation of newly and previously formed ribonucleic acid (RNA). The action on RNA seems to be independent of protein synthesis.
Studies on a Bactericidal Substance Produced by Group A Streptococci
Journal of General Microbiology
Summary: During bacteriophage studies of group A streptococci, some strains produced an inhibitory substance active against other group A strains. The inhibitory material was not found in broth cultures and could only be extracted from cultures grown in semi-solid agar; its activity was assayed by the inhibition of growth and killing of a sensitive group A strain, 12203. Viable counts showed that 2 h exposure to the factor at 37°C produced greater than 90% inhibition and more than 60% killing of the treated culture. Turbidimetric measurements indicated no gross lysis of the sensitive culture and a dose-response curve demonstrated that approximately two bactericidal factor molecules were sufficient to inactivate a colony-forming unit of strain 12203. The inhibitory factor was of low molecular weight as judged by its diffusibility; it was concentrated by lyophilization and partially purified by gel filtration on G-10 Sephadex. The factor was resistant to proteolytic enzymes, nucleases...
The Demonstration and Characterization of Deoxyribonucleases of Streptococci Group A, B, C, G And L
Acta Veterinaria Scandinavica, 1979
Streptococcus group G and L were found to produce deoxyrtbonucleases (DNases) which were demonstrated using the Toluidine Blue DNA Agar (TDA) described for staphylococcal DNases. The activity of streptococcal DNases increased in the presence of Mg++ and Ca++ ions, the pH optimum was about 7.5 and native DNA was the best enzyme substrate. It is consequently recommended to modify the TDA according to these results for the demonstration of streptococcal DNases. All streptococcal DNases, except the DNase of S. zooepidemlcus, were found to be heat-stable. lsoelectric focusing was a convenient technique for separation of streptococcal DNases and for estimation of the pI values of the DNases. S. agalactiae and S. dysgalactiae generally exhibited distinct species specific patterns in the isoelectric focusing experiments. The DNases produced by S. pyogenes were serologically related to the DNases of S. dysgalactiae and Streptococcus group G. A similar relationship was demonstrated between the DNases produced by S. equisimilis and Streptococcus group L.
Group a Streptococcal Bacteriocin: Production, Purification, and Mode of Action
Journal of Experimental Medicine, 1973
A bacteriocin, streptocin A, was isolated from the supernatant fluid of tryptic soy broth cultures of Group A streptococcus strain FF-22. Evidence was obtained which supports the view that the failure to recover active streptocin A after growth of the producer strain in certain fluid media is due to the inactivation of the bacteriocin by concomitantly synthesized streptococcal proteinase. The bacteriocin was purified 139-fold and the active product appeared to be of uniform size, having a molecular weight of approximately 8,000. Streptocin A was bactericidal, but not lytic, for a susceptible Group A streptococcus and the lethal effect was markedly temperature dependent. The bacteriocin inhibited the synthesis of DNA, RNA, and protein, and also prevented the uptake and incorporation of glucose by the sensitive cells. Degradation of RNA occurred, but appeared to be less than that produced by a staphylococcal bacteriocin. This effect may be due to differences in the killing potency of ...
Virulence and Pathogenesis of some Streptococcus species
Virulence factors and pathogenesis of some Streptococcus species, 2020
The Streptococci are a group of bacteria that can infect many animal species, causing suppurative conditions such as mastitis, metritis, polyarthritis and meningitis. They are gram positive, catalase negative, facultative anaerobes, nonmotile, fastidious bacteria and require the addition of blood or serum to culture media for growth. The majority of pathogenic Streptococci possess a serologically active carbohydrate antigenically different from one species or group of species to another. These cell wall antigens, designated A-H and K-V, are the basis of the Lancefield grouping system and are widely used by clinical laboratories for serogrouping. Most of the Streptococci that are pathogenic for animals are pyogenic and are associated with abscess formation, other suppurative conditions and septicaemia. Streptococcus suis, which is non-pyogenic, is a major pathogen of pigs, causing septicaemia, meningitis and pneumonia among other conditions. Beta-haemolytic Streptococci are generally more pathogenic than those producing alpha-haemolysis. Virulence factors include enzymes and exotoxins such as streptolysins (haemolysins), hyaluronidase, DNase, streptokinase and proteases. Polysaccharide capsules, which are major virulence factors of S. pyogenes, S. pneumoniae and most strains of S. equi, are antiphagocytic. The cell-wall M proteins of S. pyogenes, S. equi and S. porcinus are also antiphagocytic. These virulence factors play great role in the pathogenesis of different Streptococcus species.
Alterations induced by penicillin in the protein profile and cell structure of Group G Streptococcus
Current Microbiology, 1994
We investigated the effect of a subminimal concentration of penicillin on the ultrastructure and protein profile of Group G streptococci. In cells treated with penicillin (1/3 MIC), the protein content increased by 50%, and several protein bands with a molecular mass of 14–70 kDa were detected. In the hydrophilic phase, carbohydrate-containing proteins were detected by PAS staining, and in the hydrophobic phase, a group of proteins that reacted strongly with homologous antisera were observed. In terms of cell structure, Triton X-114 extraction was found to induce alterations in the cross wall of untreated cells. In bacteria treated with penicillin but not extracted with Triton X-114, the cell wall was observed to detach itself, and regions with reduced amounts of cellular material appeared in the cytoplasm. After Triton-X114 extraction, these penicillin-treated cells exhibited profound morphological changes, leading in some cases to lysis.
Bacteriocin of a Group A Streptococcus: Partial Purification and Properties
Antimicrobial Agents and Chemotherapy, 1973
The production of bacteriocin-like inhibition by certain strains of group A streptococci was demonstrated during the growth of these organisms on solid nutrient media. Active bacteriocin could not be recovered from broth cultures, possibly because of its inactivation by streptococcal proteinase. The bacteriocin, streptocin A, produced by Streptococcus pyogenes strain FF-22 was partially purified by chemical precipitation and chromatography on carboxymethyl-cellulose. Streptocin A inhibited the growth of various gram-positive organisms but none of a wide range of different gram-negative strains. The bacteriocin was inactivated by proteolytic enzymes and, although labile in alkali, it was extremely stable to heating in mild acids.
Characterization of the bacteriolytic activity of nutritionally variant streptococci
2007
The bacteriolytic activity of nutritionally variant streptococci (NVS), fastidious microaerophilic bacteria, which are members of the genera Abiotrophia and Granulicatella, was characterized in a renaturating SDS polyacrylamide gel electrophoresis system. Bacteriolytic profiles appeared quite different for the three species of NVS examined. Granulicatella adiacens or Abiotrophia defectiva each presented at least seven lytic bands, four of which were in common, while the other three were species-specific, whereas Granulicatella elegans showed six bands, which were overlapping with the G. adiacens bands. Four lytic bands were identified for enzymatic activity; D-alanyl-L-lysine hydrolase, endo-N-acetylglucosaminidase, endoacetylmuramidase, D-glutamyl-L-lysine hydrolase and acetylmuramoyl-L-alanine amidase activities could be defined. The bacteriolytic enzymes were purified and characterized for the kinetics of production during growth, autolytic activity, temperature and pH stability. r
Chapter 1. The biology of staphylococci
2009
a more certain classification of staphylococci than pigment production, wherein a positive coagulase test, which confirmed the identity of S. aureus, correlated much better with pathogenicity. Another common human pathogen is S. saprophyticus, which produces urinary tract infections in young women [2]. Staphylococcus haemolyticus is somewhat less common, but is important because it can be highly antibiotic resistant even to glycopeptides and linezolid [3]. Many other coagulase-negative strains (41 species identified at present) such as S. schleiferi and S. lugdunesis have been described, and they can produce a variety of nosocomial infections (reviewed by von Eiff et al. [4,5]). Morphology Staphylococci have a diameter of 0.7-1.2 µm and a Grampositive cell wall (Figure 1.1). Division planes occur at right angles and the cocci separate slowly, hence tetrads are frequently found. Clustering of cocci is promoted by growth on solid medium. On occasion, the clusters may be asymmetrical. Microbiological differentiation of staphylococci Growth under various conditions Staphylococci are facultative anaerobes that grow most rapidly under aerobic conditions and in the presence of CO 2. Colonies of S. aureus are β-hemolytic due to the production of several hemolysins: α-toxin, β-toxin, γ-toxin, and δ-toxin. Some S. epidermidis strains are β-hemolytic due to the production of δ-toxin [6]. Pigmentation is more pronounced after 24 hours and when held at room temperature, or in media enriched with acetate or glycerol monophosphate [7,8]. The pigments are carotenoids, whose biosynthetic pathway has recently been identified in S. aureus [9]. Pigment is not produced under anaerobic Historical perspective of the isolation and characterization of the staphylococci The staphylococci make up the family of Gram-positive cocci, Staphylococcaceae, which is in the order Bacillales. The term "staphylococcus" was synthesized from the Greek word staphyle, meaning bunch of grapes, for their ability to form microscopic grape-like clusters, and the term "coccus," meaning grain or berry. Staphylococcus aureus was one of the first bacterial pathogens identified, and causes a very broad range of infections including impetigo, folliculitis, superficial and deep skin abscesses, wound infections, osteomyelitis, suppurative arthritis, pneumonia, pleural emphysema, meningitis, septicemia and endocarditis, toxic shock syndrome, scalded skin syndrome, and food poisoning [1]. Koch first differentiated Gram-positive cocci in 1878 and recognized that different diseases such as abscesses correlated with the presence of clusters of Gram-positive cocci. Shortly thereafter, in 1884, Rosenbach differentiated species of staphylococci on the basis of colonial pigmentation, whereby the most pathogenic species formed a golden pigment and less pathogenic staphylococci formed white colonies called S. albus, now S. epidermidis. Also included in the S. albus strains were many other coagulase-negative staphylococci that fail to form pigment. Alexander Ogston, in 1880, found "a cluster forming coccus was the cause of certain pyogenous abscesses in man." When Ogston injected the pus from humans containing staphylococci into mice, it produced abscesses; however, when the pus was heated or treated with phenol, it failed to produce abscesses. In 1882, Ogston named the organism staphylococcus. Pasteur had reached similar conclusions at approximately the same time. Coagulase testing later provided 3