Related Experiment Videos
Enzymatically active Peptostreptococcus magnus: association with site of infection
C J Krepel1, C M Gohr, A P Walker
1Surgical Microbiology Research Laboratory, Medical College of Wisconsin, Milwaukee 53226.
Abstract:
Fifty-four strains of Peptostreptococcus magnus (11 were recovered from abdominal infections, 18 were from nonpuerperal breast abscesses, and 21 were from diabetic foot infections; the type strain and three other strains were from the American Type Culture Collection, Rockville, Md.) and the type strain of Peptostreptococcus micros were tested for their ability to produce various enzymes, including catalase, hippurate hydrolase, serine dehydratase, threonine dehydratase, collagenase, gelatinase, alkaline phosphatase, and esterase C4. The data were analyzed by cluster analysis. The results showed that all but one strain could be assigned to either of two distinct, valid clusters. The first cluster of 11 strains was composed of strains that were relatively inactive, having produced one or two of the eight strain-dependent enzymes. The second was a large cluster of strains (n = 43) that were considerably more active, all having produced at least three enzymes; the vast majority of strains (89%) produced four or more enzymes. The unclustered strain produced one enzyme that was different from that produced by the strains in the first cluster. The chi 2 test of homogeneity applied to the clustering solution indicated that greater enzyme activity was significantly associated with the site of infection (P less than 0.001). The more enzymatically active P. magnus strains were recovered significantly more often from nonpuerperal breast abscesses and diabetic foot infections than they were from abdominal infections. These results may provide insight into the nature of certain polymicrobial soft tissue infections and suggest that (i) P. magnus may participate more in nonpuerperal breast and diabetic foot infections than in abdominal infections and that (ii) peptostreptococcal production of proteolytic enzymes may have an important adjunctive effect on the pathogenesis of certain soft tissue infections.
Insights
Enzyme activity in Peptostreptococcus magnus strains varied by infection site. More active strains were linked to diabetic foot and breast infections, suggesting a role in soft tissue infection pathogenesis.
Area of Science:
- Microbiology
- Infectious Diseases
- Bacterial Pathogenesis
Background:
- Peptostreptococcus magnus is a bacterium implicated in various infections.
- Understanding bacterial enzyme production is crucial for elucidating infection mechanisms.
Purpose of the Study:
- To investigate the enzymatic profiles of Peptostreptococcus magnus strains.
- To determine if enzyme activity correlates with the site of infection.
Main Methods:
- Fifty-four strains of Peptostreptococcus magnus and one strain of Peptostreptococcus micros were tested for eight enzyme activities.
- Cluster analysis was used to group strains based on enzyme production.
- Chi-squared test assessed the association between enzyme activity and infection site.
Main Results:
- Two distinct clusters of P. magnus strains emerged based on enzyme activity: one with low activity (1-2 enzymes) and another with high activity (≥3 enzymes).
- Higher enzymatic activity was significantly associated with nonpuerperal breast abscesses and diabetic foot infections (P < 0.001).
- Less enzymatically active strains were more frequently isolated from abdominal infections.
Conclusions:
- Peptostreptococcus magnus strains exhibit varying enzymatic capabilities, correlating with infection source.
- Increased proteolytic enzyme production by P. magnus may contribute to the pathogenesis of soft tissue infections, particularly in diabetic foot and nonpuerperal breast infections.