Spontaneously Occurring Bacterial Transformations in Mice

Ottolenghi-Nightingale, Elena

doi:10.1128/jb.100.1.445-452.1969

Cited by 14 publications

(12 citation statements)

References 17 publications

(22 reference statements)

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“…The frequency of transformation in the murine lung varied with different pneumococcal strains, as previously observed in the peritoneal cavity (19). Transformation of CD-VII-Smr, for example, was more common than transformation of IIIS-1R6.…”

Section: Resultssupporting

confidence: 62%

“…Although intraperitoneal transformations between strains R36NCSmr and IIIS-1R6 have been reported in mice (4,18,19), we detected such a transformation in the doubly infected lungs of only 1 mouse among 117 injected with ethanol and 91 injected with saline (see Discussion). In contrast to the observations of Conant and Sawyer (4), no transformants were isolated from the blood.…”

Section: Resultsmentioning

confidence: 49%

“…Pneumococcal strains. The strains used have been fully described (19). The pertinent characteristics of these strains are presented in Table 1.…”

mentioning

confidence: 99%

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Effect of Ethanol on the Clearance of Airborne Pneumococci and the Rate of Pneumococcal Transformations in the Lung

Auerbach-Rubin

Ottolenghi-Nightingale

1971

Infect Immun

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The rate of clearance of pneumococci from the lungs of mice infected by aerosols was found to vary inversely with the virulence of the pneumococci. Treatment of of the mice with ethanol delayed the clearance and increased the rate of pneumococcal transformations in vivo. The transfer of genetic information from one Pneumococcus to another by transformation with freshly released deoxyribonucleic acid is known to occur both in vitro (1, 10, 16) and in vivo (4, 8, 18, 19). Conant and Sawyer (4) have recently reported that it will occasionally occur in mice infected by intrabronchial inoculation. The objective of the present study has been to design an experimental model in which pneumococcal transformation will occur consistently in the lungs. The design is based on the evidence that (i) pneumococci must multiply rapidly and accumulate in relatively large numbers for transformation to be efficient (4) and (ii) that ethanol intoxication will slow the pulmonary clearance of airborne bacteria (6, 12, 20, 23). MATERIALS AND METHODS Mice. Strain CD-1, male, pathogen-free albino mice weighing 21 to 25 g were obtained from Charles River Laboratories, Wilmington, Mass. The lungs of these mice are essentially devoid of bacteria. Antibiotics. Streptomycin sulfate (Sm; Eli Lilly & Co., Indianapolis, Ind.) was added to blood-agar medium to a final concentration of 500 jg/ml. Erythromycin gluceptate (ery; Eli Lilly & Co.) was added to a final concentration of 0.1 Ag/ml. Deoxyribonuclease. Pancreatic deoxyribonuclease (IX recrystallized, Worthington Biochemical Corp., Freehold, N.J.) was used in a final concentration of 10 Ag/ml together with a final concentration of 0.007% MgSO4-7H20. Ethanol and its determination in murine blood. Absolute ethanol, diluted to 10% in saline, was in-' This work was taken from a dissertation submitted in partial fulfillment of the requirements for the Ph.D. degree at the

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Section: Resultssupporting

confidence: 62%

Section: Resultsmentioning

confidence: 49%

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Effect of Ethanol on the Clearance of Airborne Pneumococci and the Rate of Pneumococcal Transformations in the Lung

Auerbach-Rubin

Ottolenghi-Nightingale

1971

Infect Immun

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“…As his approach involves the use of large amounts of heat-killed donors, it relies on artificial conditions and is not useful as a method for studying gene transfer in vivo. However, a few pioneering studies from the 1960s have demonstrated the occurrence of transformation during mixed pneumococcal infection in mice and man (Ottolenghi & MacLeod, 1963;Conant & Sawyer, 1967;Ottolenghi-Nightingale, 1969, 1972. In mice, transformation was shown to take place even when living donor and recipient cells were injected at different sites or 6 h apart.…”

Section: Discussionmentioning

confidence: 99%

Regulation of natural genetic transformation and acquisition of transforming DNA inStreptococcus pneumoniae

Johnsborg¹,

Håvarstein²

2009

FEMS Microbiol Rev

127

122

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The ability of pneumococci to take up naked DNA from the environment and permanently incorporate the DNA into their genome by recombination has been exploited as a valuable research tool for 80 years. From being viewed as a marginal phenomenon, it has become increasingly clear that horizontal gene transfer by natural transformation is a powerful mechanism for generating genetic diversity, and that it has the potential to cause severe problems for future treatment of pneumococcal disease. This process constitutes a highly efficient mechanism for spreading beta-lactam resistance determinants between streptococcal strains and species, and also threatens to undermine the effect of pneumococcal vaccines. Fortunately, great progress has been made during recent decades to elucidate the mechanism behind natural transformation at a molecular level. Increased insight into these matters will be important for future development of therapeutic strategies and countermeasures aimed at reducing the spread of hazardous traits. In this review, we focus on recent developments in our understanding of competence regulation, DNA acquisition and the role of natural transformation in the dissemination of virulence and beta-lactam resistance determinants.

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“…Under natural conditions pneumococcus might participate in gene exchange when located in biofilms in places such as the nasopharynx, the common carrier state of this microorganism [46,106]. In fact, there are data supporting the idea that DNA‐mediated spontaneous transformations may occur in nature, even interspecific transformation between pneumococci and streptococci, and that they may play a role in bacterial infections [127,128]. Interestingly, type 9 pneumococci were transformed by DNA released from living unencapsulated pneumococci sprayed onto the pharynx in a healthy human carrier [128].…”

Section: Cell Wall Hydrolasesmentioning

confidence: 99%

Recent trends on the molecular biology of pneumococcal capsules, lytic enzymes, and bacteriophage

2004

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Streptococcus pneumoniae has re-emerged as a major cause of morbidity and mortality throughout the world and its continuous increase in antimicrobial resistance is rapidly becoming a leading cause of concern for public health. This review is focussed on the analysis of recent insights on the study of capsular polysaccharide biosynthesis, and cell wall (murein) hydrolases, two fundamental pneumococcal virulence factors. Besides, we have also re-evaluated the molecular biology of the pneumococcal phage, their possible role in pathogenicity and in the shaping of natural populations of S. pneumoniae. Precise knowledge of the topics reviewed here should facilitate the rationale to move towards the design of alternative ways to combat pneumococcal disease.

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Spontaneously Occurring Bacterial Transformations in Mice

Cited by 14 publications

References 17 publications

Effect of Ethanol on the Clearance of Airborne Pneumococci and the Rate of Pneumococcal Transformations in the Lung

Effect of Ethanol on the Clearance of Airborne Pneumococci and the Rate of Pneumococcal Transformations in the Lung

Regulation of natural genetic transformation and acquisition of transforming DNA inStreptococcus pneumoniae

Recent trends on the molecular biology of pneumococcal capsules, lytic enzymes, and bacteriophage

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