Levofloksatsin — keng ta'sir doirasiga ega bo‘lgan ftorxinolonlar guruhiga mansub mikroblarga qarshi bakteritsid ta’sirga ega preparat. U DNK-girazani (topoizomeraza II) va topoizomeraza IV ni bloklaydi, bu esa DNKning superspiralizatsiyasi va uzilishlarning tiklanishini buzadi, natijada DNK sintezi to‘xtaydi. Levofloksatsin bakteriya sitoplazmasi, hujayra devori va membranalarida chuqur morfologik o‘zgarishlarga olib keladi. Levofloksatsinga in vitro sharoitida quyidagi mikroorganizmlar sezgir (minimal bostiruvchi konsentratsiyasi 2 mg/l dan kam):
Aerob grammusbat mikroorganizmlar: Corynebacterium diphtheriae, Enterococcus spp. (jumladan Enterococcus faecalis), Listeria monocytogenes, Staphylococcus spp. (leukotoksinli, koagulaza-manfiy metitsillin sezgir/umumiy sezgir shtammlar), jumladan Staphylococcus aureus (metitsillin sezgir shtammlar), Staphylococcus epidermidis (metitsillin sezgir shtammlar), Streptococcus spp. (S va G guruhlari), Streptococcus agalactiae, Streptococcus pneumoniae (penitsillin sezgir/rezistent shtammlar), Streptococcus pyogenes, Streptococcus viridans guruhi (penitsillin sezgir/rezistent shtammlar).
Aerob grammanfiy mikroorganizmlar: Acinetobacter spp. (jumladan Acinetobacter baumannii), Actinobacillus actinomycetemcomitans, Citrobacter freundii, Eikenella corrodens, Enterobacter spp. (jumladan Enterobacter cloacae, Enterobacter aerogenes, Enterobacter agglomerans), Escherichia coli, Gardnerella vaginalis, Haemophilus ducreyi, Haemophilus influenzae (ampitsillinga sezgir/rezistent shtammlar), Haemophilus parainfluenzae, Helicobacter pylori, Klebsiella spp. (jumladan Klebsiella oxytoca, Klebsiella pneumoniae), Moraxella catarrhalis (β-laktamaza ishlab chiqaruvchi va ishlab chiqarmaydigan shtammlar), Morganella morganii, Neisseria gonorrhoeae (penitsillinaza ishlab chiqaruvchi va ishlab chiqarmaydigan shtammlar), Neisseria meningitidis, Pasteurella spp. (jumladan Pasteurella canis, Pasteurella dagmatis, Pasteurella multocida), Proteus mirabilis, Proteus vulgaris, Providencia spp. (jumladan Providencia rettgeri, Providencia stuartii), Pseudomonas spp. (jumladan Pseudomonas aeruginosa), Salmonella spp., Serratia spp. (jumladan Serratia marcescens).
Anaerob mikroorganizmlar: Bacteroides fragilis, Bifidobacterium spp., Clostridium perfringens, Fusobacterium spp., Peptostreptococcus spp., Propionibacterium spp., Veillonella spp.
Boshqa mikroorganizmlar: Bartonella spp., Chlamydia pneumoniae, Chlamydia psittaci, Chlamydia trachomatis, Legionella pneumophila, Mycobacterium spp. (jumladan Mycobacterium leprae, Mycobacterium tuberculosis), Mycoplasma hominis, Mycoplasma pneumoniae, Rickettsia spp., Ureaplasma urealyticum.
O‘rtacha sezgir mikroorganizmlar (minimal bostiruvchi konsentratsiya 4 mg/l dan ko‘p):
Aerob grammusbat mikroorganizmlar: Corynebacterium urealyticum, Corynebacterium xerosis, Enterococcus faecium, Staphylococcus epidermidis (metitsillinga rezistent shtammlar), Staphylococcus haemolyticus (metitsillinga rezistent shtammlar).
Aerob grammanfiy mikroorganizmlar: Burkholderia cepacia, Campylobacter jejuni, Campylobacter coli.
Anaerob mikroorganizmlar: Bacteroides thetaiotaomicron, Bacteroides vulgatus, Bacteroides ovatus, Prevotella spp., Porphyromonas spp.
Rezistent mikroorganizmlar (minimal bostiruvchi konsentratsiya 8 mg/l dan ko‘p):
Aerob grammusbat mikroorganizmlar: Corynebacterium jeikeium, Staphylococcus aureus (metitsillinga rezistent shtammlar), boshqa Staphylococcus spp. (koagulaza-manfiy metitsillinga rezistent shtammlar).
Aerob grammanfiy mikroorganizmlar: Alcaligenes xylosoxidans.
Boshqa mikroorganizmlar: Mycobacterium avium.
Levofloksatsin keng spektrli mikroblarga qarshi yuqori samarali vosita bo‘lib, ko‘plab patogen mikroorganizmlar, jumladan antibiotiklarga chidamli shtammlarga nisbatan samaradorligini namoyon qiladi.