|Systematic (IUPAC) name|
|Pregnancy cat.||B1 (AU) B (US)|
|Legal status||Prescription Only (S4) (AU)|
|Mol. mass||455.47 g/mol|
| (what is this?)
Cefotaxime (INN) (pron.: //) is a third-generation cephalosporin antibiotic. Like other third-generation cephalosporins, it has broad spectrum activity against Gram positive and Gram negative bacteria. In most cases, it is considered to be equivalent to ceftriaxone in terms of safety and efficacy.
Mechanism of action 
It inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs). This inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.
Cefotaxime, like other β-lactam antibiotics does not only block the division of bacteria, including cyanobacteria, but also the division of cyanelles, the photosynthetic organelles of the Glaucophytes, and the division of chloroplasts of bryophytes. In contrast, it has no effect on the plastids of the highly developed vascular plants. This supports the endosymbiotic theory and indicates an evolution of plastid division in land plants. 
Clinical use 
Cefotaxime is used for infections of the respiratory tract, skin, bones, joints, urogenital system, meninges, and bloodstream. It generally has good coverage against most Gram-negative bacteria, with the notable exception of Pseudomonas. It is also effective against most Gram-positive cocci except for Enterococcus. It is active against penicillin-resistant strains of Streptococcus pneumoniae. It has modest activity against the anaerobic Bacteroides fragilis. In meningitis, cefotaxime crosses the blood–brain barrier better than cefuroxime.
Usage in Plant Tissue Culture 
Cefotaxime is the only cephalosporin which has very low toxicity in plants, even at higher concentration (up to 500mg/L). It is widely used to treat plant tissue infections with Gram negative bacteria, while vancomycin is used to treat the plant tissue infections with Gram positive bacteria.
The syn-configuration of the methoxyimino moiety confers stability to β-lactamase enzymes produced by many Gram-negative bacteria. Such stability to β-lactamases increases the activity of cefotaxime against otherwise resistant Gram-negative organisms.
- Cefotaxime drug information
- Britta Kasten und Ralf Reski (1997): β-lactam antibiotics inhibit chloroplast division in a moss (Physcomitrella patens) but not in tomato (Lycopersicon esculentum). Journal of Plant Physiology 150, 137-140. 
- cefotaxime for plant tissue culture
- vancomycin for plant cell culture