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Updated: Mar 1, 2026
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Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS
Published on: July 11, 2016
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Characterization of bacteroides melaninogenicus
Journal of Clinical Microbiology
|October 1, 1976
Summary
This study classifies Bacteroides melaninogenicus strains into three subspecies using biochemical tests. The classification aids in understanding these bacteria, which are found in clinical infections and normal flora.
Area of Science:
- Microbiology
- Bacteriology
Background:
- Bacteroides melaninogenicus is a significant bacterium found in human clinical infections and normal flora.
- Accurate classification of bacterial species and subspecies is crucial for understanding their role in health and disease.
Purpose of the Study:
- To reliably classify 58 human isolates of Bacteroides melaninogenicus into their respective subspecies.
- To identify key characteristics for differentiating between Bacteroides melaninogenicus subspecies.
- To assess antimicrobial susceptibility across the identified subspecies.
Main Methods:
- Biochemical testing of 58 human isolates of Bacteroides melaninogenicus.
- Analysis of pigment production and ultraviolet light fluorescence.
- Gas-liquid chromatography for end-product analysis.
- Antimicrobial susceptibility testing against 12 agents.
- Reproducibility checks for all tests.
Main Results:
- Fifty-eight strains were reliably classified into three groups corresponding to described subspecies based on seven key characteristics.
- Seven distinguishing characteristics identified: acid production, n-butyric acid production, esculin hydrolysis, starch hydrolysis, indole production, effect on milk, and lipase production.
- Hydrogen gas production in peptone-yeast-fructose medium may serve as an additional distinguishing feature.
- Generally, no significant differences in antimicrobial susceptibility were observed among the three groups.
- Two strains showed elevated penicillin G minimal inhibitory concentrations (16 and 32 U/ml).
- Three strains failed to produce black pigment despite prolonged incubation.
Conclusions:
- A reliable method for classifying Bacteroides melaninogenicus into three subspecies using seven biochemical characteristics has been established.
- The identified subspecies exhibit generally similar antimicrobial susceptibility profiles.
- Further research may explore the significance of pigment production variations and hydrogen gas production.
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