The penetration of several antibiotics into human polymorphonuclear leucocytes was measured with a bioassay. The aminoglycosides (gentamicin, netilmicin), oxacillin and LY146032, a new lipopeptidic antibiotic, had a penetration which was generally less than 60%, whereas new fluoro-quinolones (enoxacin, ciprofloxacin, CI934, Ro236240) and rifamycins (rifampicin, LM427) were concentrated 2.4 to 14.2-fold. The concentration of vancomycin and teicoplanin associated with the neutrophils appeared to be saturable over the range of extracellular concentrations tested (5-20 mg/l). Coumermycin, an inhibitor of DNA-gyrase, was highly concentrated (11.3 to 16.6-fold) within the neutrophils. The penetration of clindamycin and erythromycin was low (0.60- to 1.48-fold).

Molecular diagnosis based on genomic amplification methods such as real-time PCR assay has been reported as an alternative to conventional culture for early detection of invasive candidiasis. However, a major limitation of the molecular method is the difficulty associated with breaking fungal cell walls since the DNA extraction step still requires more than half of a working day. It has been suggested that PCR detection of free template DNA in serum is preferred over the use of whole blood for the diagnosis of systemic candidiasis. In this study, two conventional procedures (the first [the HLGT method] consists of boiling sera in an alkaline guanidine-phenol-Tris reagent, and the second [the PKPC method] uses proteinase K digestion, followed by organic extraction) and three commercially available kits for DNA isolation were evaluated for sensitivity, purity, cost, and use of template for most clinically important Candida species in a TaqMan-based PCR assay. To optimize these procedures, we evaluated the effect of adding 0.5% bovine serum albumin to DNA extracts and found that it decreased the effects of inhibitors. The QIAamp DNA blood kit did significantly shorten the duration of the DNA isolation but was among the most expensive procedures. Furthermore, the QIAamp DNA blood kit proved to be as sensitive as the HLGT DNA isolation method for PCR amplification from 52 serum samples from hematology or oncology patients with clinically proven or suspected systemic Candida infections. All PCR-positive samples showed approximately the same Candida species load by both procedures (100% correspondence), whereas one discordant result was obtained between PCR and blood culture.The management of invasive fungal infections has been hampered by the inability to diagnose the infection at an early stage of disease. However, diagnosis remains difficult, since the only sign of infection may be a prolonged fever that is refractory to antibacterial treatment. In recent years, efforts have been made to develop molecular-biology-based methods for rapid diagnosis, which is crucial to the treatment and recovery of patients suffering from systemic candidiasis. In a comparison of the molecular diagnoses obtained by a real-time PCR-based method to the results of blood culture, the sensitivity and specificity of the molecular method with a C. albicans-specific probe observed with 122 clinical blood samples were 100 and 97%, respectively (12). However, a major limitation of the molecular method in comparison to blood culture was the difficulty associated with problems in breaking fungal cell walls since the DNA extraction step is still a limiting factor, requiring more than half of a working day.Actually, there is no consensus concerning the best blood fractions to be tested for diagnosis of systemic candidiasis. Several PCR methods have been developed for use either on whole-blood samples (7,11,12) or on serum samples (1, 3-5). However, in addition to being too time-consuming and laborintensive, protocols for extraction of cellular candi...

One hundred and sixty-nine strains of new species of the family Enterobacteriaceae, isolated mainly from the environment, were tested to determine their susceptibilities to 13 antibiotics and 4 antiseptics or disinfectants. All the species were susceptible to aminoglycosides, doxycycline, and trimethoprim but were resistant to chloramphenicol. Susceptibility to ,-lactams varied more among the strains. However, all the strains were cefotaxime susceptible, apart from some Buttiauxella agrestis strains for which MICs were greater than 256 ,ug/ml. The antiseptic MBCs were similar to those published elsewhere for species of the Enterobacteriaceae of clinical origin. No resistance to chlorhexidine was observed. On the other hand, the environmental strains presented a greater resistance to active chlorine than did the reference strains.Members of the family Enterobacteriaceae are the most common cause of nosocomial infections (8). In 15 years, the number of enterobacterial species has grown from about 20 to more than 130. The exact clinical significance of these new species, which are often detected in a wet environment (e.g., water and soil), remains largely unknown. However, they are isolated with growing frequency during pathogenic processes, especially in immunosuppressed subjects (4).The present study was aimed at evaluating the susceptibilities to 13 antibiotics and 4 antiseptics or disinfectants of 169 strains of new species of Enterobacteriaceae which were isolated mainly from the environment. MATERIALS AND METHODSOrganisms. A total of 169 strains representing 22 newly described species of Enterobacteriaceae were tested. Of these, 17 strains were from sewage, 26 were from surface water, 38 were from soil, 58 were from drinking water, and 30 were of medical origin. The species were identified as previously described (2).Antibiotics. The 13 antibiotics tested were supplied in the form of powders. The antibiotics and their sources were as follows: ampicillin and amikacin (Bristol, Paris, France), amoxicillin-clavulanic acid and ticarcillin (Beecham, Paris, France), cephalothin (Glaxo, Paris, France), cefoxitin (Merck Sharp & Dohme, Paris, France), cefotaxime (Roussel-Uclaf, Romainville, France), gentamicin (Unilabo, Dardilly, France), tobramycin (Lilly, Saint-Cloud, France), doxycycline (Pfizer, Orsay, France), trimethoprim (Roche, Neuilly-sur-Seine, France), chloramphenicol (Clin-Midy, Paris, France), and colistin (Roger Bellon, Neuilly-surSeine, France).The MICs were determined by the microdilution method (1). The various antibiotic dilutions were prepared according to a twofold geometric progression in the culture medium, which was Mueller-Hinton broth (pH 7.4) supplemented with 50 p.g of calcium per ml and 25 mg of magnesium per ml.Portions (100 RI) were placed in the wells of a microdilution plate. The bacterial inoculum obtained by a 10-2 dilution after incubation for 18 h at 35°C in brain heart broth was * Corresponding author. Antiseptics and disinfectants. We tested 5% aqueous chlorhexidine digluconate (I...

The in-vitro activity of ciprofloxacin, a quinolone-carboxylic acid derivative, was compared with those of carbenicillin, azlocillin, cefsulodin, ceftazidime, tobramycin and amikacin against 187 non-fermenters. Only one of the 131 strains of Pseudomonas spp. was not inhibited by 1 mg/l of ciprofloxacin, while these isolates appeared highly resistant to carbenicillin, azlocillin and cefsulodin. Ciprofloxacin was also the best agent against Flavobacterium, Alcaligenes faecalis and Acinetobacter calcoaceticus with MIC90's respectively of 0.5, 4 and 8 mg/l. This new compound appeared bactericidal, and we found a small or no inoculum effect with ciprofloxacin.

An in vitro model is described that simulates serum and tissue levels of antibiotic, allowing the exposure of bacteria to changing concentrations of antibiotic with little dilution of the inoculum. A bacterial suspension is placed in the outer chamber of a unit through which runs a bundle of 150 polysulfone hollow fibers that retain proteins of greater than 10,000 daltons. These "capillaries" are in contact with the tubular lumen of a perfusion system. Antibiotic is injected into the tubing and circulated by a pump. At desired intervals given volumes of perfusate are removed and replaced with antibiotic-free broth (resulting in decreasing drug concentrations), or a constant level can be maintained. Samples from the outer chamber are taken for determination of bacterial counts and antibiotic levels. This method allows for the in vitro determination of persistent antibiotic effects and comparison of bolus and continuous infusions as well as the effects of single or combined antibodies on bacterial killing and regrowth.