Identification of coagulase-negative staphylococci with the API staph system

Area of Science:

• Clinical Microbiology
• Bacteriology

Background:

• Coagulase-negative staphylococci are increasingly important in clinical infections.
• Antibiotic resistance in staphylococci necessitates accurate identification methods.

Purpose of the Study:

• To evaluate a commercially available kit for identifying coagulase-negative staphylococci based on biochemical criteria.
• To determine the species distribution and antibiotic sensitivity of staphylococcal isolates from clinical infections.

Main Methods:

• Utilized a kit with 19 biochemical tests for staphylococcal identification.
• Identified 100 strains of coagulase-negative staphylococci from various body sites.
• Assessed antibiotic sensitivity patterns for each identified isolate.

Main Results:

• The kit successfully identified over 90% of Staphylococcus isolates to the species level.
• Key species identified included Staphylococcus epidermidis (54 strains) and Staphylococcus saprophyticus (22 strains).
• Antibiotic resistance varied, with widespread penicillin resistance and specific resistance patterns for novobiocin, tetracycline, sulfamethoxazole, and nalidixic acid.

Conclusions:

• The commercial kit provides a reliable method for identifying coagulase-negative staphylococci.
• Understanding species-specific antibiotic resistance is crucial for managing staphylococcal infections.
• The findings highlight the need for continued surveillance of antibiotic resistance in staphylococci.