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Moraxella catarrhalis does not grow on nutrient agar without sodium chloride supplementation
Toshio Chida1, Etsuko Sawabe, Emi Ono
1Department of Microbiology and Immunology, Graduate School of Health Sciences, Tokyo Medical and Dental University, Bunkyo-ku, Japan. T.Chida.mtec@tmd.ac.jp
Microbiology and Immunology
|July 22, 2005
Summary
Moraxella catarrhalis requires sodium chloride for growth on nutrient agar, unlike most commensal Neisseria species. This difference in salt tolerance can be used to differentiate between these bacteria in laboratory settings.
Area of Science:
- Microbiology
- Bacterial Physiology
Background:
- Moraxella catarrhalis is a significant human pathogen.
- Commensal Neisseria species are common inhabitants of the human upper respiratory tract.
- Distinguishing between M. catarrhalis and Neisseria species is important for clinical and epidemiological studies.
Purpose of the Study:
- To investigate the differential growth requirements of Moraxella catarrhalis and commensal Neisseria species on nutrient agar.
- To evaluate the potential of sodium chloride supplementation as a selective marker for M. catarrhalis.
Main Methods:
- Culturing of 58 Moraxella catarrhalis strains and 51 commensal Neisseria spp. strains on nutrient agar with and without sodium chloride supplementation.
- Observation and recording of bacterial growth.
Main Results:
- None of the 58 Moraxella catarrhalis strains grew on nutrient agar without sodium chloride.
- 49 out of 51 commensal Neisseria spp. strains grew on nutrient agar without sodium chloride.
- Significant difference in growth observed based on sodium chloride presence.
Conclusions:
- Nutrient agar without sodium chloride supplementation is a suitable medium for differentiating Moraxella catarrhalis from commensal Neisseria species.
- This simple method can aid in the preliminary screening of clinical and environmental samples.
