In-vitro and in-vivo antibacterial activity of quinupristin/dalfopristin

Abstract

Quinupristin/dalfopristin is a new water-soluble streptogramin antimicrobial agent comprising quinupristin and dalfopristin in a ratio of 30:70. The in-vitro spectrum of activity includes most multi-resistant Gram-positive aerobes, important Gram-negative aerobes, Gram-positive anaerobes and intracellular bacteria that are causal agents of respiratory, blood and cutaneous infections. Of particular note, quinupristin/dalfopristin is active against multidrug-resistant isolates of Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecium, and against penicillin-resistant and/or erythromycin-resistant Streptococcus pneumoniae. The combination is also active against staphylococci showing both constitutive and inducible erythromycin resistance. Bactericidal activity and a prolonged post-antibiotic effect have also been noted for quinupristin/dalfopristin against Gram-positive cocci. Gram-negative bacteria susceptible to quinupristin/dalfopristin include Moraxella catarrhalis, Legionella spp. and Mycoplasma spp. Overall, the spectrum of antibacterial activity indicates a potential role for this combination in the treatment of difficult-to-treat Gram-positive infections, including those caused by multidrug-resistant organisms. Since this activity extends to Gram-negative respiratory bacteria, quinupristin/dalfopristin may also find a role in the treatment of atypical, as well as typical, pneumonia.

Methicillin-Resistant, Quinupristin-Dalfopristin-Resistant Staphylococcus aureus with Reduced Sensitivity to Glycopeptides

“…However, with the emergence of intermediate susceptibility to glycopeptides, first reported from sporadic cases in many countries (12, 20) and more recently also from an outbreak of infections (11), other treatment alternatives such as quinupristin-dalfopristin and linezolid have become important. Quinupristin-dalfopristin is a combination of streptogramin B and A compounds with a synergistic activity against most gram-positive bacteria (8,14).Resistance to the B component is mediated by methylation of 23S rRNA which confers macrolide-lincosamide-streptogramin B (MLS B ) resistance when the erm genes are expressed constitutively (7). A second mechanism is hydrolysis of the drug by a lactonase encoded by the vgbA and the vgbB genes, respectively (1, 6).…”

“…However, with the emergence of intermediate susceptibility to glycopeptides, first reported from sporadic cases in many countries (12,20) and more recently also from an outbreak of infections (11), other treatment alternatives such as quinupristin-dalfopristin and linezolid have become important. Quinupristin-dalfopristin is a combination of streptogramin B and A compounds with a synergistic activity against most gram-positive bacteria (8,14).…”

Determination of Macrolide, Lincosamide and Streptogramin B Resistance in Staphylococcus aureus Strains by Phenotypical Methods and Investigation of In Vitro Activity of Quinupristin/Dalfopristin

“…K/D, %30 kinupristin (Streptogramin B), %70 dalfopristin (Streptogramin A) içer-mektedir ve 50S ribozomal alt üniteye bağlana-rak hem peptid zincir uzamasını hem de peptidil transferaz enzimini inhibe ederek etki göster-mektedir. K/D Gram pozitif bakterilere, özellik-le de MRSA, viridans streptokok ve vankomisine dirençli Enterococcus faecium'a karşı in vitro etkinliğe sahiptir (3,(6)(7)(8)(9) . (10,11) .…”

Susceptibility of Gram Positive Cocci Isolated from Clinical Samples to Quinupristin/Dalfopristin and Comparison with Other Antibiotics at Tepecik Training and Research Hospital

“…Bu durum, literatürde bildirilen çalışmaların sonuçları ile uyumluluk gös-termektedir. 2,[13][14][15][16] MRSA izolatları tüm beta-laktamlara ve tedavide kullanılan diğer antibiyotik sınıflarına da dirençli olduğu için, yeni antibiyotiklerin henüz kullanıma girmediği dönemde glikopeptit antibiyotikler (vankomisin ve teikoplanin) tek tedavi seçeneği olarak kalmıştır.…”

“…Bu nedenle tedavide kullanılabilecek yeni antibiyotiklere ihtiyaç duyulmaktadır. 2 Kinopristin-dalfopristin, linezolit, daptomisin ve tigesikline dirençli Gram pozitif bakteri enfeksiyonlarının tedavisine alternatif olarak başta Amerika Birleşik Devletleri (ABD) olmak üzere dünyada kullanıma sunulmuştur. 3 Kinopristin/dalfopristin kombinasyonu, streptogramin grubunda yer alan, yarı sentetik ve parenteral uygulanan ilk antibiyotiktir.…”