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

Abstract

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

N‐Acetylcysteine Improves Group B Streptococcus Clearance in a Rat Model of Chronic Ethanol Ingestion

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Factors influencing the immune enhancement of intrapulmonary bactericidal mechanisms

“…The latter laboratory extended these observations to demonstrate that in addition to bacterial genera differences, strain differences existed in the intrapulmonary killing pattern of P. aeruginosa in mice (32). The exceedingly rapid rate of intrapulmonary killing of S. pneumoniae and S. aureus during the initial hours after aerosol challenge has been confirmed by a number of laboratories (1,22,25).…”

Exposure-dependent effects of ethanol on the innate immune system

“…Both acute and chronic ethanol exposure have been shown to affect the phagocytic potential and the ability of these professional antigen presenting cells to express antigen and co-stimulatory molecules on their surface (Table 1). Studies from as early as the 1960's and 70's have shown immunomodulatory effects of ethanol on bacterial clearance (Auerbach-Rubin and Ottolenghi-Nightingale, 1971;Laurenzi et al, 1963). Recent studies have begun to reveal a more in-depth understanding of ethanol's effects on phagocytosis.…”