Beta-lactam antibiotics and viridans group streptococci

Area of Science:

• Microbiology
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Viridans group streptococci (VGS) are a diverse group of bacteria.
• Penicillin (PEN) resistance in VGS is a growing concern, linked to altered penicillin-binding proteins.
• The Argentinean context shows significant non-susceptibility to PEN among VGS isolates.

Approach:

• This review synthesizes current data on VGS susceptibility to beta-lactam antimicrobials.
• Focuses on the specific scenario of VGS antimicrobial resistance in Argentina.
• Examines the mechanisms of PEN resistance, including alterations in penicillin-binding proteins.

Key Points:

• One to two-thirds of VGS isolates in Argentina exhibit non-susceptibility to penicillin.
• Third-generation cephalosporins and carbapenems demonstrate superior in vitro efficacy against VGS compared to penicillin.
• Penicillin non-susceptibility has been linked to increased mortality in VGS bacteremia cases.

Conclusions:

• Penicillin is becoming less reliable for treating VGS infections, necessitating susceptibility testing.
• Alternative antibiotics such as third-generation cephalosporins, carbapenems, and vancomycin are crucial for managing resistant VGS infections.
• Treatment of VGS endocarditis must be guided by isolate susceptibility, with vancomycin as a viable option for penicillin-resistant cases.