[Coagulase-negative Staphylococci isolated from patients. III. Phage typing]

Area of Science:

• Microbiology
• Bacteriology
• Epidemiology

Background:

• Coagulase-negative staphylococci (CoNS) are significant opportunistic pathogens.
• Accurate identification and subtyping of CoNS are crucial for infection control and epidemiological studies.
• Phage typing is a traditional method for bacterial strain differentiation.

Purpose of the Study:

• To evaluate the effectiveness of two experimental phage typing sets (Dutch and American) for coagulase-negative staphylococci.
• To assess the specificity of these phages, particularly against Staphylococcus epidermidis.
• To determine the potential utility of phage typing for CoNS research.

Main Methods:

• Subjecting clinical isolates of coagulase-negative staphylococci to phage typing.
• Utilizing two distinct sets of typing phages: the Dutch (Verhoef) set and the American (Paris) set.
• Analyzing the lysis patterns and calculating the percentage of lysed strains for each phage set.

Main Results:

• The Dutch phage set lysed 30.1% of 153 CoNS strains.
• The American phage set lysed 19.6% of 378 CoNS strains.
• American phages showed higher specificity for Staphylococcus epidermidis (32.4% lysis) compared to Dutch phages (34.3% lysis).

Conclusions:

• The current effectiveness of the evaluated phage typing sets is insufficient for reliable differentiation of coagulase-negative staphylococci.
• Further development and optimization of phage typing strategies are needed for CoNS research.
• The observed specificity of American phages for S. epidermidis warrants further investigation.