GV129606 is a new parenteral trinem antibiotic belonging to the beta-lactam class. It combines broad-spectrum activity (against gram-negative and -positive bacteria, aerobes and anaerobes), with high potency and resistance to
beta-lactamases. Comparative in vitro and in vivo antibacterial activities were determined for
GV129606 against more than 400 recent clinical isolates (aerobes, including
beta-lactamase producers, and anaerobes), using representative
antibacterial agents (
meropenem,
piperacillin,
ceftazidime,
cefpirome,
ciprofloxacin, and
gentamicin for aerobes and
metronidazole,
cefoxitin,
piperacillin, and
clindamycin for anaerobes). Against
methicillin-susceptible staphylococci and streptococci,
GV129606 and
meropenem were the most active of the drugs tested.
GV129606 showed an MIC for 90% of strains tested (MIC90) ranging from < or =0.015 to 0.06 microg/ml against
methicillin-susceptible staphylococci and Streptococcus sanguis, Streptococcus pyogenes, and Streptococcus agalactiae. Against
penicillin-susceptible and -resistant Streptococcus pneumoniae isolates,
GV129606,
meropenem, and
cefpirome showed MIC90s of < or =0.015 and 1 microg/ml, respectively.
Meropenem was the most active compound against members of the family Enterobacteriaceae with MIC90s of < or =0.5 microg/ml. Against these species,
GV129606 possessed activity superior to those of
piperacillin,
ceftazidime,
cefpirome, and
gentamicin, with MIC90s of < or =8 microg/ml, but its activity was two- to sixfold less than that of
ciprofloxacin (with the exception of Proteus rettgeri and Providencia stuartii). Haemophilus spp., Moraxella catarrhalis, Neisseria gonorrhoeae, and Pseudomonas aeruginosa were also included in the spectrum of
GV129606.
GV129606 showed good antianaerobe activity, similar to
metronidazole. It was stable against all clinically relevant
beta-lactamases (similar to
meropenem). The in vitro activity was confirmed in vivo against
septicemia infections induced in mice by selected gram-positive and -negative bacteria with 50% effective doses (ED50s) of < or =0.05 and < or =0.5 mg/kg of
body weight/dose, respectively.
GV129606 was as effective as
meropenem against
septicemia in mice caused by
ceftazidime-resistant Pseudomonas aeruginosa, exhibiting an ED50 of 0.33 mg/kg/dose.