Detection of beta-lactamase produced by Staphylococcus intermedius

Area of Science:

• Veterinary Microbiology
• Clinical Diagnostics

Background:

• Beta-lactamase enzymes confer bacterial resistance to beta-lactam antibiotics.
• Accurate detection of beta-lactamase is crucial for guiding antimicrobial therapy in veterinary medicine.
• Staphylococcus intermedius is a common pathogen in canine infections.

Purpose of the Study:

• To compare the efficacy of six different methods for detecting beta-lactamase production in Staphylococcus intermedius.
• To evaluate a cost-effective, laboratory-prepared iodometric method against commercial assays.

Main Methods:

• Six methods were evaluated: one iodometric, two chromogenic, and three acidometric.
• The iodometric method served as the reference standard.
• Beta-lactamase detection was performed on 105 Staphylococcus intermedius isolates from dogs.

Main Results:

• Overall, 55.0% of isolates tested positive for beta-lactamase production.
• The laboratory-prepared iodometric method showed high reliability, comparable to five commercial methods.
• Correlation coefficients between commercial methods were generally below 0.900, except for one acidometric and one chromogenic method.

Conclusions:

• The inexpensive, paper strip iodometric method is a reliable and recommended alternative for routine beta-lactamase detection in clinical laboratories.
• This method offers a cost-effective solution without compromising diagnostic accuracy.
• The findings support the adoption of this practical method for veterinary diagnostic settings.