Phage typing of Staphylococcus intermedius
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Published on: September 5, 2013
G D Overturf1, D A Talan, K Singer
1Department of Pathology, University of California, Los Angeles.
Abstract:
Staphylococcus intermedius, a coagulase-positive staphylococcal species, is a common canine pathogen and a rare human wound pathogen. A total of 145 strains of S. intermedius (ATCC 29663, 4 reference strains, 4 human isolates, 44 canine infection isolates, and 92 isolates from canine gingiva) were screened for lysogenic phage by a modified Fisk method. Nineteen phage preparations were prepared for preliminary typing experiments. Lytic activity was observed on 93 of 145 (64.1%) isolates, yielding 44 lytic patterns with individual strains susceptible to one or more phages. Five phages lysed only a single strain, but lytic patterns varied from 1 to 11 lytic phages per isolate. A distinct lytic pattern did not separate canine or human wound isolates from canine gingival isolates. All human wound isolates fell into the two most common canine gingival or wound patterns; the single human nasopharyngeal isolate was not lysed by any phage. Twenty-two of 44 (55%) canine wound isolates and 65 of 92 (71%) gingival isolates yielded lytic patterns. Lysogenic phages are common in S. intermedius. This preliminary study suggests that phage typing may be a useful tool in distinguishing epidemiologically related strains.
Insights
Lysogenic phages are common in Staphylococcus intermedius, a canine pathogen. Phage typing showed varied lytic patterns, suggesting its utility in differentiating related bacterial strains.
Area of Science:
- Veterinary Microbiology
- Bacteriology
- Molecular Biology
Background:
- Staphylococcus intermedius is a significant canine pathogen and an infrequent cause of human infections.
- Understanding the genetic diversity and epidemiological links of S. intermedius strains is crucial for both veterinary and public health.
Purpose of the Study:
- To investigate the prevalence of lysogenic phages in Staphylococcus intermedius strains.
- To evaluate the potential of phage typing as a tool for differentiating S. intermedius isolates from various sources.
Main Methods:
- Screening of 145 S. intermedius isolates (including canine infections, gingival samples, human isolates, and reference strains) for lysogenic phages using a modified Fisk method.
- Preparation of 19 phage lysates for preliminary typing experiments.
- Analysis of lytic activity and determination of lytic patterns for each isolate.
Main Results:
- Lytic activity was detected in 64.1% (93/145) of S. intermedius isolates, revealing 44 distinct lytic patterns.
- Lytic patterns did not differentiate between canine and human wound isolates versus canine gingival isolates.
- Human wound isolates matched common canine patterns, while a nasopharyngeal isolate was non-lysed.
Conclusions:
- Lysogenic phages are prevalent in Staphylococcus intermedius.
- Phage typing demonstrates potential as a valuable method for distinguishing epidemiologically related strains of S. intermedius.
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