In vivo bactericidal activities of ciprofloxacin and pefloxacin in an experimental model of Serratia marcescens endocarditis

A novel microbe-drug association prediction model based on stacked autoencoder with multi-head attention mechanism

Microbes are intimately tied to the occurrence of various diseases that cause serious hazards to human health, and play an essential role in drug discovery, clinical application, and drug quality control. In this manuscript, we put forward a novel prediction model named MDASAE based on a stacked autoencoder (SAE) with multi-head attention mechanism to infer potential microbe-drug associations. In MDASAE, we first constructed three kinds of microbe-related and drug-related similarity matrices based on known microbe-disease-drug associations respectively. And then, we fed two kinds of microbe-related and drug-related similarity matrices respectively into the SAE to learn node attribute features, and introduced a multi-head attention mechanism into the output layer of the SAE to enhance feature extraction. Thereafter, we further adopted the remaining microbe and drug similarity matrices to derive inter-node features by using the Restart Random Walk algorithm. After that, the node attribute features and inter-node features of microbes and drugs would be fused together to predict scores of possible associations between microbes and drugs. Finally, intensive comparison experiments and case studies based on different well-known public databases under 5-fold cross-validation and 10-fold cross-validation respectively, proved that MDASAE can effectively predict the potential microbe-drug associations.

Bactericidal effect of pefloxacin and fosfomycin against Pseudomonas aeruginosa in a rabbit endocarditis model with pharmacokinetics of pefloxacin in humans simulated in vivo

The bactericidal activity of pefloxacin and fosfomycin alone and in combination against Pseudomonas aeruginosa was evaluated in an experimental rabbit endocarditis model after 24 h of treatment. Two strains with intermediate susceptibility to pefloxacin and good susceptibility to fosfomycin were tested. The serum kinetics obtained during administration of 400 mg every 12 h in humans were simulated in the animals using computer-controlled variable-flow infusion. Fosfomycin was administered as a continuous infusion at a constant flow, allowing a steady-state concentration of 47.4 +/- 11.9 mg/ml to be reached in serum. In valvular vegetations, pefloxacin was less bactericidal than fosfomycin, and in combination treatment, it reduced (but did not abolish) the bactericidal effect of fosfomycin. The duration of the pretreatment interval (12-48 h) had a negative effect on the bactericidal activity of both drugs, especially that of fosfomycin.

Comparative efficacies of ciprofloxacin and pefloxacin alone or in combination with fosfomycin in experimental endocarditis induced by multidrug-susceptible and -resistant Pseudomonas aeruginosa

The in vivo efficacy of ciprofloxacin or pefloxacin alone or in combination with fosfomycin was evaluated in experimental aortic valve endocarditis induced in 133 rabbits by a multidrug-susceptible or multidrug-resistant strain of Pseudomonas aeruginosa. Therapy was initiated early (12 h after infection), when bacterial counts in aortic valve vegetations were relatively low, or late (48 h after infection), when vegetations contained a larger inoculum. Antibodies were administered as a continuous 24-h intravenous infusion. Mean steady-state levels of ciprofloxacin (64 mg/kg), pefloxacin (64 mg/kg), and fosfomycin (300 mg/kg) in serum were 2.5, 4.2, and 63.9 mg/liter, respectively. For the multidrug-susceptible strain, all regimens except pefloxacin alone significantly reduced the number of CFU per gram of vegetation versus controls, whether treatment was performed early or late. For the multidrug-resistant strain, none of the regimens showed differences from untreated controls, except ciprofloxacin-fosfomycin, which significantly reduced bacterial counts in vegetations compared with controls when therapy was begun early (4.1 +/- 1.1 log10 CFU/g of vegetation; P < 0.001 versus the control). These data suggest that combination of fosfomycin with ciprofloxacin or pefloxacin is more effective than ciprofloxacin or pefloxacin alone for the therapy of severe infections caused by multidrug-susceptible P. aeruginosa.