Quantitative Measurement of the Growth of Pleuropneumonia-like Organisms1

Smith, Paul F.

doi:10.1128/aem.4.5.254-259.1956

Cited by 18 publications

(13 citation statements)

References 7 publications

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“…Several procedures have been investigated to obtain growth curves. Smith (8) suggested that the sensitivity of the turbidimetric method could be increased by a preliminary concentration of cells by centrifugation. However, as many as 5 x 105 viable cells per ml may remain in the supernatant fluid after centrifugation at forces up to 40,000 x g. As many as 108 cells per ml may remain in the supernatant fluid after centrifugation at 10,000 rev/min.…”

Section: Discussionmentioning

confidence: 99%

“…The mnument of acid production has been used to assay growth of fermentative species (2). Growth may be assayed quantitatively by measurement of dry weight (2,8), deoxyribonucleic acid and protein nitrogen (2, 6). However, in addition to the cautions noted by Smith (10), i.e., cells must be washed free of medium, although diffusion of cell contents must be minimized, the loss of cells during centrifugation may yield inconsistent data.…”

Section: Discussionmentioning

confidence: 99%

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Rapid Determination by Light Scattering of Growth Parameters of Mycoplasma laidlawii in Liquid Media

Wolf

Marcus

1969

Applied Microbiology

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An impediment to progress in the study of the course of growth, the effects of medium components, antibiotics, etc., of Mycoplasma has been the cumbersome methods of growth measurement currently in use. Heretofore, it required the plating of numerous samples during growth, at least in triplicate, after appropriate dilution, followed by a delay of 2 to 3 days before the colonies developed so that counts could be made. We applied the technique of light scattering to measure the growth of Mycoplasma laidlawii in liquid culture continuously in a manner analogous to the use of absorbancy for bacteria. Scattered light measurements precisely paralleled data obtained by the tedious method of plate counts and were available immediately during the development of the culture. The lower limit of sensitivity with the system described is 105 Mycoplasma per ml. The presence of serum in the medium lowers sensitivity somewhat. However, concentrations of serum up to 10% are easily tolerated. Higher serum content may require calibration curves. Thus the technique may be used with many pathogens, etc., that require serum to develop. One can easily and rapidly measure differences in growth rates as well as final cell yields during the course of growth, rather than 3 days later, after colonies have developed.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Rapid Determination by Light Scattering of Growth Parameters of Mycoplasma laidlawii in Liquid Media

Wolf

Marcus

1969

Applied Microbiology

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“…M. pulmonis was grown in broth on the surface of Povitsky bottles (14). The growth was washed three times in phosphate buffered saline (PBS), pH 6.8, and the number of colony-forming units (CFU) was determined by plate count (10). A lysed suspension of logarithmic phase M. pulmonis was assayed for catalase activity by the perborate method (5).…”

Section: Methodsmentioning

confidence: 99%

Relationship of Hydrogen Peroxide Production by Mycoplasma pulmonis to Virulence for Catalase-deficient Mice

Brennan

Feinstein

1969

J Bacteriol

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Mycoplasma pulmonis, an etiological agent of murine pneumonia, produced about 0.065 ,umoles of hydrogen peroxide (H202) per hr per 1010 colony-forming units. When glucose was present at a concentration of 0.01 M, H202 production was increased by 50%. To determine if H202 production by M. pulmonis could be correlated with virulence, normal, acatalasemic, and acatalatic mice were infected with the organism. Three days after infection with M. pulmonis significantly more acatalatic mice had pneumonia than did normal or acatalasemic mice. The pneumonia in acatalatic mice was also more severe than in the other two groups. Five days after infection, pneumonia in the acatalatic mice was resolved, whereas normal mice were severely affected. The presence of pneumonia and the severity were correlated with the recovery of M. pulmonis from the lesions. In vitro studies of the effect of catalase on M. pulmonis showed that exogenously supplied catalase stimulated the growth of M. pulmonis at 37 C and prolonged its survival at 25 C. Hemolysis of sheep blood, guinea pig blood, rabbit blood, and normal and acatalasemic mouse blood by M. pulmonis was inversely related to the catalase activity of the erythrocytes. These findings suggest that H202 secretion contributes to the virulence of M. pulmonis and to the death of the microorganism in the absence of host catalase.

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“…of sterile 0.5 per cent solution of Difco proteose peptone No. 3 in distilled water. One-tenth-milliliter amounts of each dilution were plated in duplicate.…”

Section: Massmentioning

confidence: 99%

Growth‐curve Studies of Pleuropneumonialike Organisms*

Kelton

1960

Annals of the New York Academy of Sciences

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In 1932 Holmes and Pirie' attempted to construct growth curves of the bovine pleuropneumonia organism by correlating the degree of reduction of methylene blue with the amount of growth. Keller and Morton2 pointed out the futility of turbidimetric measurements of whole cultures in the construction of growth curves of human strains of pleuropneumonialike organisms (PPLO). These workers determined a growth curve using a colony-count method in which the volume of inoculum was correlated to the surface area of a field of the microscope, and the average of 100 fields was used as the count.The work on quantitative determinations of PPLO has been reviewed by Smith.3 A study of the methods for determining PPLO growth was presented, and it was concluded that the following techniques were suitable for general laboratory use: (1) measurement of turbidity following concentration of the culture by centrifugation; (2) measurement of the colony diameter; and (3) colony count using 0.01 ml. of culture (or diluted culture) deposited on the surface of agar, incubated, and counted under low magnification.In this study, growth curves of 2 human, 2 avian, and 1 saprophytic PPLO were determined using a colony-count method of assay. The method appears to be accurate and requires no complicated techniques or special equipment. Materials and MethodsGrowth curves were determined on the following strains of PPLO: P S U J Infected chicken embryo

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Quantitative Measurement of the Growth of Pleuropneumonia-like Organisms1

Cited by 18 publications

References 7 publications

Rapid Determination by Light Scattering of Growth Parameters of Mycoplasma laidlawii in Liquid Media

Rapid Determination by Light Scattering of Growth Parameters of Mycoplasma laidlawii in Liquid Media

Relationship of Hydrogen Peroxide Production by Mycoplasma pulmonis to Virulence for Catalase-deficient Mice

Growth‐curve Studies of Pleuropneumonialike Organisms*

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