Related Experiment Video
Updated: Jun 19, 2026
Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
Published on: February 23, 2014
THE VIABILITY OF THE PNEUMOCOCCUS AFTER DRYING: A STUDY OF ONE OF THE FACTORS IN PNEUMONIC INFECTION
1A Study from the Department of Pathology, Columbia University, under a Grant from the Commission for the Investigation of Acute Respiratory Diseases, of the Department of Health of the City of New York.
Abstract:
I. In moist sputum kept in the dark at room temperatures the average life of the pneumococcus is eleven days, though considerable variations may be noted in different specimens of sputum. In the same sputum kept at o degrees C. the average life of the organism is thirty-five days. In sputum kept at room temperature and in a strong light the pneumococcus lives less than five days. II. In dried sputum (a) in the dark the pneumococcus lives on an average thirty-five days; (b) in diffuse light, thirty days; (c) in sunlight, less than four hours. III. In powdered sputum even when kept in the dark the death of the pneumococcus takes place in from one to four hours. When exposed to sunlight death occurs within an hour. IV. No important differences were noted in the life of the pneumococcus when dried on glass, tin, or wood. On cloth the life was usually slightly longer than on non-absorbing surfaces. V. Sprayed sputum particles remain in suspension for twenty-four hours, but all masses of a size sufficient to contain bacteria settle at a rate of about 40 cm. per hour. VI. When sputum containing pneumococci is sprayed the organisms rarely survive for more than an hour, and often die in less time. The substance upon which the particles fall makes but little difference in the life of the organism. On cloth a slight prolongation is occasionally noted, due perhaps to the slow drying. VII. The mucus of the sputum exerts a destructive action on the pneumococcus. VIII. Exposure of bacterial spray to sunlight while in suspension results in the destruction of the pneumococcus within half an hour.
Insights
The pneumococcus bacterium survives longer in dried sputum in the dark (35 days) than in moist sputum (11 days). Sunlight significantly reduces pneumococcus viability in both moist and dried states.
Area of Science:
- Microbiology
- Environmental Health
- Infectious Disease Transmission
Background:
- Understanding the environmental persistence of pathogenic bacteria is crucial for infection control.
- The pneumococcus (Streptococcus pneumoniae) is a significant respiratory pathogen.
- Factors influencing bacterial survival in respiratory droplets and secretions require detailed investigation.
Purpose of the Study:
- To determine the survival time of the pneumococcus under various environmental conditions.
- To assess the impact of temperature, light, and sputum state on pneumococcus viability.
- To evaluate the survival of pneumococci in sprayed sputum particles.
Main Methods:
- Incubation of pneumococcus-containing sputum under controlled conditions of temperature (room temperature, 0°C) and light (dark, diffuse light, strong light, sunlight).
- Drying sputum on various surfaces (glass, tin, wood, cloth) and assessing bacterial survival.
- Investigating the viability of pneumococci in sprayed sputum particles and their settling rates.
- Analyzing the effect of sputum mucus on pneumococcus survival.
Main Results:
- In moist sputum, pneumococci survived an average of 11 days at room temperature and 35 days at 0°C, but less than 5 days in strong light.
- In dried sputum, survival averaged 35 days in the dark, 30 days in diffuse light, and less than 4 hours in sunlight.
- Powdered sputum led to rapid death (1-4 hours in dark, <1 hour in sunlight).
- Sprayed pneumococci rarely survived over an hour, with sunlight rapidly inactivating them in suspension.
Conclusions:
- Environmental factors, particularly light and temperature, significantly influence pneumococcus survival.
- Dried sputum offers a longer survival period for pneumococci compared to moist sputum, especially in the absence of light.
- The mucus component of sputum has a detrimental effect on pneumococcus viability.
- The risk of transmission via airborne droplets is limited due to rapid inactivation, especially in sunlight.
More Related Videos
09:20Investigating the Effects of Probiotics on Pneumococcal Colonization Using an In Vitro Adherence Assay
Published on: April 28, 2014
12:21A Mouse Model for the Transition of Streptococcus pneumoniae from Colonizer to Pathogen upon Viral Co-Infection Recapitulates Age-Exacerbated Illness
Published on: September 28, 2022
Related Concept Videos
01:30Pneumonia III: Complications and Assessment
01:29Pneumonia II: Pathophysiology
01:29Pneumonia I: Introduction
01:30Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
01:14Atypical Pneumonia
01:30Pneumonia V: Nursing management and Prevention
The nurse must practice strict medical asepsis and adhere to infection control guidelines to minimize healthcare-associated infections.
Enhance airway patency
Position the patient correctly to facilitate drainage of the affected lung segments. Manual or mechanical percussion and vibration can also be employed.