Susceptibility of clinical isolates to cephalexin, cefazolin and cefotaxime

Area of Science:

• Microbiology
• Infectious Diseases
• Pharmacology

Background:

• Antibiotic resistance is a growing global health concern.
• Cephalosporins are a critical class of antibiotics used to treat bacterial infections.
• Understanding the in vitro susceptibility patterns of local bacterial isolates is essential for guiding effective antibiotic therapy.

Purpose of the Study:

• To determine the in vitro susceptibility of recent clinical isolates to three commonly available cephalosporins in India: cephalexin, cefazolin, and cefotaxime.
• To compare the efficacy of these cephalosporins against Gram-positive cocci and Gram-negative bacilli.
• To identify the most effective cephalosporin for empirical treatment of common bacterial infections in the Indian context.

Main Methods:

• The Kirby-Bauer disc diffusion method was employed.
• Three hundred and seventeen recent clinical isolates were tested.
• Susceptibility testing was performed for cephalexin, cefazolin, and cefotaxime.

Main Results:

• Cefazolin demonstrated the highest sensitivity rates against Gram-positive cocci (71.8%), followed by cefotaxime (62.7%) and cephalexin (52.7%).
• Cefotaxime exhibited significant efficacy against Gram-negative bacilli, with only 8.8% resistance, compared to cefazolin (39%) and cephalexin (57.5%).
• All Pseudomonas aeruginosa isolates were resistant to cephalexin and cefazolin, with 32.6% sensitive to cefotaxime.

Conclusions:

• Cefotaxime is the preferred cephalosporin for treating Gram-negative bacterial infections in this setting.
• Cefazolin is the most effective option for Gram-positive cocci infections.
• Local susceptibility data are crucial for optimizing cephalosporin use and combating antibiotic resistance.