In vitro activities of quinupristin/dalfopristin and eight other antimicrobial agents against 360 clinical isolates from Korea

The emergence of multi-drug resistant gram-positive cocci such as methicillin-resistant (MR) staphylococci, vancomycin-resistant (VR) enterococci, and vancomycin-intermediate resistant S. aureus (VISA) has given new urgency to the development of new antimicrobial agents. One of these is quinupristin/dalfopristin (Q/D). We decided to determine the susceptibility of gram-positive cocci isolated at two university hospitals in Seoul to Q/D and compare the results with eight other antimicrobial agents. We investigated 120 isolates of S. aureus including 49 MRSAs and one VISA, 120 isolates of coagulase negative staphylococci (CNS), 64 E. faecalis and 56 E. faecium, including seven strains of VR E. faecium. Minimum inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) for several antimicrobials, including vancomycin and Q/D, were determined by broth microdilution. All S. aureus including VISA were susceptible to Q/D. Q/D MIC90 for both methicillin-susceptible S. aureus (MSSA) and MRSA was 0.25 g/mL. 49 (87.5%) of 56 E. faecium including six of seven VR E. faecium were susceptible to Q/D. E. faecalis were not susceptible to Q/D (only 1.5% susceptible), but were inhibited by ampicillin (94% susceptible) or vancomycin (95%). CNS was susceptible to Q/D (96% susceptible) and vancomycin (100% susceptible). One of 38 staphylococci and two of 17 E. faecium were tolerant to Q/D. In conclusion, Q/D showed excellent activity against all species of gram-positive cocci including MRSA, VISA, and VR E. faecium except E. faecalis, and may provide a valuable option for the treatment of infections caused by these emerging nosocomial pathogens of gram-positive cocci.

Diclazuril interaction with avoparcin and virginiamycin as growth promoters in growing rabbits

The effect of feeding avoparcin and virginiamycin [10 ppm] alone or in combination with diclazuril [1 ppm] to growing rabbits for 10 successive weeks on absolute body weight, body gain and feed efficiency were studied. Moreover, their effects on blood picture and the activity of AST, ALT as well as urea and creatinine levels were also investigated, In addition, the residual pattern of avoparcin and virginiamycin were also demonstrated using the microbiological assay technique. Avoparcin or Virginiamycin supplementation with the basal ration significantly increased the absolute body weight [5.7 or 8.8%], amount of feed consumed [3.2 or 1.6%] as well as plucked weight. Avoparcin was found to be compatible with diclazuril as their combination induced large improvement in the body weights [10.6%]; and the amount of feed consumed [6.2%]. Combination of diclazuril with virginiamycin did not after the absolute body weight and the weight gain, but increased the amount of feed consumed [4.5%] as compared with group fed virginiamycin alone. Avoparcin or virginiamycin alone and combination of diclazuril with avoparcin significantly increased R.B.Cs count, hemoglobin content and PCV. Combination of diclazuril with avoparcin increased the activity of AST and ALT and that with virginiamycin increased AST and ALT activity as well as urea and creatinine levels. No residues of either avoparcin or virginiamycin were detected at the end of the experiment in organs and tissues of rabbits fed 10 ppm for 10 successive weeks. In conclusion, Feeding avoparcin or virginiamycin to growing rabbits at 10 ppm stimulates growth, feed efficiency and blood picture. Diclazuril [1ppm] was found to be more compatible with avoparcin than viginiamycin

Antibacterianos de acción sistémica, parte II: otros grupos de antibióticos / Systemic antibacterial drugs, part II: other groups of antibiotics

Se presenta la segunda parte de una revisión bibliográfica sobre los antibacterianos de acción sistémica, la cual incluye grupos de antibióticos tan importantes como aminociclitoles, aminoglucósidos, diaminopirimidinas, estreptograminas, fosfomicinas, fusidanos, glicopéptidos, lincosamidas, macrólidos, nitrofuranos, nitroimidazoles, polipéptios, quinolonas y rifamicinas