Which statement correctly identifies the rapid beta-lactamase test use?

Which statement correctly identifies the rapid beta-lactamase test use?

• A. For Staphylococcus aureus isolates only
• B. For Escherichia coli isolates only
• C. For Haemophilus influenzae isolates to guide therapy
• D. For Pseudomonas aeruginosa isolates only

Answer: (C)

Rapid beta-lactamase testing is used to detect whether an organism produces beta-lactamase, an enzyme that inactivates many beta-lactam antibiotics. For Haemophilus influenzae, beta-lactamase production is a common resistance mechanism that makes ampicillin and related penicillins ineffective. Running a rapid beta-lactamase test on H. influenzae isolates helps clinicians choose an effective therapy—if the test is positive, a beta-lactamase–stable antibiotic or a beta-lactamase inhibitor–combination (like amoxicillin-clavulanate) is preferred; if negative, penicillins may still be effective. While beta-lactamase testing can be relevant for other organisms, its use to guide therapy is particularly important for Haemophilus influenzae, making the statement the best fit.

Rapid beta-lactamase testing is used to detect whether an organism produces beta-lactamase, an enzyme that inactivates many beta-lactam antibiotics. For Haemophilus influenzae, beta-lactamase production is a common resistance mechanism that makes ampicillin and related penicillins ineffective. Running a rapid beta-lactamase test on H. influenzae isolates helps clinicians choose an effective therapy—if the test is positive, a beta-lactamase–stable antibiotic or a beta-lactamase inhibitor–combination (like amoxicillin-clavulanate) is preferred; if negative, penicillins may still be effective. While beta-lactamase testing can be relevant for other organisms, its use to guide therapy is particularly important for Haemophilus influenzae, making the statement the best fit.