CONTEXT: The spread of drug-resistant Streptococcus pneumoniae in the community is a public health problem in developed and developing nations, but whether antibiotic use is responsible for the increase in drug resistance is not known. OBJECTIVE: To analyze the relationship between penicillin-resistant S pneumoniae (PRSp) pharyngeal carriage and characteristics of beta-lactam use. DESIGN: Observational study of children attending 20 randomly sampled schools. SETTING: The Loiret, in the center of France. PARTICIPANTS: A total of 941 children, 3 to 6 years old. MAIN OUTCOME MEASURE(S): Pharyngeal carriage of S pneumoniae, antibiotic use, and medical events during the preceding 30 days. Pneumococcal penicillin G sodium minimal inhibitory concentrations and serotyping were performed. RESULTS: Medical illnesses and the use of antibiotics were not associated with PRSp carriage. However, oral beta-lactam use was associated with an increased risk of PRSp carriage (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.1-8.3; P=.03). Children treated by low daily doses of an oral beta-lactam (defined as lower than clinical recommendations) had an increased risk of PRSp carriage, as compared with children who did not (OR, 5.9; 95% CI, 2.1-16.7; P=.002). A treatment of long duration (>5 days) with a beta-lactam was associated with an increased risk of PRSp carriage (OR, 3.5; 95% CI, 1.3-9.8; P=.02). CONCLUSIONS: Our results suggest that a low daily dose and a long duration of treatment with an oral beta-lactam contribute to the selective pressure in promoting pharyngeal carriage of PRSp.

Anti-Bacterial Agents↗

PubMed1998

Effects of diclofenac on experimental streptococcal necrotizing fasciitis (NF) in rabbit.

Aggravation of necrotizing fasciitis (NF) by the administration of non-steroidal antiinflammatory drugs (NSAIDs) has recently been suggested. A rabbit model of streptococcal NF was used to study the effects of parenteral administration of an NSAID on NF evolution and outcome. Of 16 rabbits inoculated with a Streptococcus pyogenes suspension together with staphylococcal alpha toxin, 8 were treated with two doses of 4 mg/kg diclofenac on day 1 after inoculation. Clinical, bacteriological and histological studies were performed until day 10. Under our experimental conditions, NSAID treatment significantly limited NF extension. A specific inverse relationship between the extent of inflammation and bacterial density in NF lesions was observed on day 1 after inoculation in the treated group suggesting that the greater severity of NF in humans treated with an NSAID could be due to the therapeutic delay induced by the misleading clinical effects of the NSAID, and not to inhibition of antibacterial defence.

Animals↗

PubMed1998

Inappropriateness and variability of antibiotic prescription among French office-based physicians.

OBJECTIVE: To describe oral antibiotic prescription in the community. DESIGN: Audit of anti-infective prescribing in office-based medical practice. SETTING: Center of France, in the Loiret, a 600,000 inhabitant administrative division. MAIN OUTCOME MEASURES: Clinical hypothesis and antimicrobial drugs used as well as daily doses and durations of treatment. RESULTS: Respiratory tract infections with a presumed viral etiology accounted for 36% of prescriptions. In children, a high percentage of antibiotic prescriptions were underdosed as compared to clinical recommendations, particularly in acute otitis media. The variability of the daily dose was high, with coefficients of variation over 40% in acute otitis media or acute tracheobronchitis. Whatever the clinical hypothesis, the duration of treatment was close to 8 days. In acute otitis media, the coefficient of variation was 14%, the lowest for all diagnoses. CONCLUSION: Our investigation identified two main areas for improving antimicrobial drug prescribing: (1) reduction of useless prescriptions in respiratory tract infections with a presumed viral etiology, and (2) increasing the prescribed daily dose of antimicrobials to the recommended levels.

Administration, Oral↗

PubMed1998

The Th1 to Th2 shift induced by Schistosoma mansoni does not exacerbate murine aids (MAIDS).

Schistosoma mansoni infection in mice is associated with a switch from a Th1 to a Th2-type cytokine response. The role of Th1 and Th2 responses in immune dysregulations associated with AIDS and murine AIDS (MAIDS) is controversial, but a Th2 bias could be associated with disease progression, raising the hypothesis that helminth infections might accelerate the retroviral disease progression. Here, we used the murine model of AIDS to evaluate the course of the viral disease during co-infection with S. mansoni. C57BL/6 mice were infected with S. mansoni cercariae 8 weeks before intravenous challenge with the LP-BM5 retroviral complex. MAIDS did not progress faster in co-infected mice, in terms of spleen and inguinal lymphadenopathy size, ecotropic virus titres in the spleen, or in vitro proliferative responses to mitogen. Th2 cytokine production was not enhanced in co-infected animals, except for an isolated increase in IL-4 production 21 weeks after LP-BM5 infection. Co-infected animals had significantly lower lymph node and spleen weights than mice infected with LP-BM5 only. MAIDS did not influence the granulomatous response to S. mansoni in the liver of co-infected mice. Finally, infection with S. mansoni neither enhanced Th2 cytokine production nor accelerated MAIDS progression in animals subsequently challenged with LP-BM5.

Animals↗

PubMed1998

Pharmacodynamics of macrolides, azalides, and streptogramins: effect on extracellular pathogens.

The efficacy of macrolides against extracellular pathogens depends on extracellular levels of free drug and the organisms' patterns of susceptibility to the macrolides. The effect of macrolides against most bacteria is considered time-dependent. The size of inoculum affects erythromycin's activity against streptococci and, moreover, against staphylococci. The optimal effect is observed at a pH of 8. A significant postantibiotic effect (PAE), lasting approximately 9 hours, has been shown with erythromycin and roxithromycin against gram-positive cocci. Azalides share the same properties. For the streptogramin synercid, a dose-dependent bactericidal activity within a range of low concentrations has been demonstrated. The serum area under the curve appeared to be the best predictor of in vivo effect on the mouse thigh model. Synercid also exhibited a prolonged PAE (approximately 10 hours) against the main pathogens of its spectrum. A better knowledge of the pharmacodynamic properties of macrolides and streptogramins is essential for definition of proper dosing regimens.

Anti-Bacterial Agents↗

PubMed1998

Unfortunate in vitro selection of resistant Candida albicans with severe clinical consequences.

Explore the source record for details and available documents.

Amphotericin B↗

PubMed1998

Photo quiz. II. Disseminated histoplasmosis.

Explore the source record for details and available documents.

Histoplasmosis↗

PubMed1998

Trends in antimicrobial drug use in the community--France, 1981-1992.

Trends in the use of antimicrobials in France between 1980-1981 and 1991-1992 were analyzed. Data were obtained from surveys of health and ambulatory care, which were based on national probability samples. In a 3-month period in 1980, 17% of the population of France was treated with an antibiotic, compared with 25% in 1991 (P < .001). The frequency of respiratory tract infections with a presumed viral etiology that were diagnosed and treated with antibiotics increased by 86% for adults and 115% for children in the 11-year period. The proper use of cephalosporins must be encouraged, and vigilance is required in view of the increased improper use of fluoroquinolones, mainly for respiratory tract infections with a presumed viral etiology.

Adult↗

PubMed1998

Cryptosporidium parvum biliary tract infection in adult immunocompetent and immunosuppressed mice.

Biliary tract infection by Cryptosporidium parvum is a frequent complication of intestinal cryptosporidiosis in immunosuppressed patients. Although biliary tract infection can be produced in immunosuppressed models as a late complication of intestinal infection, there is no infection model in immunocompetent animals. A murine model of biliary tract cryptosporidiosis was developed by direct intra-gall bladder injection of C. parvum oocysts. In adult immunocompetent mice, intracellular parasitic stages were detected in the epithelium of the common bile duct in all animals on day 7 post-inoculation (p.i.). These findings were associated with a strong inflammatory reaction. Infection was cleared between days 14 and 21 p.i. All animals developed significant levels of specific serum and bile IgG, IgA and IgM. Dexamethasone treatment resulted in the inability of animals to eradicate the parasite and the establishment of ileal parasitism. This model can be used to study the immunological mechanisms involved in the control of biliary cryptosporidiosis.

Animals↗

PubMed1998

Secretion of sparfloxacin from the human intestinal Caco-2 cell line is altered by P-glycoprotein inhibitors.

The mechanism of intestinal secretion of the difluorinated quinolone sparfloxacin was investigated with the epithelial cell line Caco-2 and was compared to that of the P-glycoprotein (P-gp) substrate vinblastine. The P-gp inhibitors verapamil and progesterone significantly increased the epithelial cell accumulation of both vinblastine and sparfloxacin. This increase is likely to result from an inhibition of drug secretion since both vinblastine uptake and sparfloxacin uptake are known to proceed through a passive transmembrane diffusion. The unidirectional fluxes across cell monlayers grown on permeable filters indicated that a net secretion of sparfloxacin and vinblastine occurred across Caco-2 cells. These secretions were significantly inhibited by the MDR-reversing agent verapamil. We conclude that the P-gp is likely to be involved in the intestinal elimination of the difluorinated quinolone sparfloxacin.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

Efficacy of teicoplanin and autoradiographic diffusion pattern of [14C]teicoplanin in experimental Staphylococcus aureus infection of joint prostheses.

Prosthesis infections are difficult to cure. Infection with methicillin-resistant staphylococci is becoming more common in patients with orthopedic implants. Using a recently developed model of methicillin-resistant Staphylococcus aureus (MRSA) infection of a knee prosthesis, we compared the efficacies of teicoplanin and vancomycin. [14C]teicoplanin diffusion in this model was also studied by autoradiography. A partial knee replacement was performed with a silicone implant fitting into the intramedullary canal of the tibia, and 10(7) CFU of MRSA was injected into the knee. Treatment with teicoplanin or vancomycin (20 or 60 mg/kg of body weight, respectively, given intramuscularly twice daily) was started 7 days after inoculation and was continued for 7 days. The teicoplanin and vancomycin MICs for MRSA were 1 microg/ml. Mean peak and trough levels in serum were 39.1 and 23.5 microg/ml, respectively, for teicoplanin and 34.4 and 18.5 microg/ml, respectively, for vancomycin. Fifteen days after the end of therapy, the animals were killed and their tibias were removed, pulverized, and quantitatively cultured. Teicoplanin and vancomycin significantly reduced (P < 0. 05) the bacterial density (2.7 +/- 1.3 and 3.3 +/- 1.6 log10 CFU/g of bone, respectively) compared to those for the controls (5.04 +/- 1.4 log10 CFU/g of bone). The bacterial covents of teicoplanin- and vancomycin-treated rabbits were comparable. The [14C]teicoplanin autoradiographic diffusion patterns in rabbits with prostheses, two of which were uninfected and two of which were infected, were studied 15 days after inoculation. Sixty minutes after the end of an infusion of 250 microCi of [14C]teicoplanin, autoradiography showed that in the infected animals, the highest levels of radioactivity were located around the prosthesis and in the periosteum, bone marrow, and trabecular bone. Radioactivity was less intense in epiphyseal disk cartilage, femoral cartilage, articular ligaments, and muscles and was weak in compact bone. A similar distribution pattern was seen in uninfected rabbits. Thus, teicoplanin may represent an effective alternative therapy for the treatment of these infections.

Animals↗

PubMed1998

Effects of Salmonella typhimurium infection and ofloxacin treatment on glucose and glutamine metabolism in Caco-2/TC-7 cells.

The effects of both Salmonella typhimurium infection and 5 mM ofloxacin treatment on 2 mM glutamine and 5 mM glucose metabolism in the enterocyte-like Caco-2/TC-7 cell line were studied. These cells utilized glutamine (212.07 +/- 16.75 [mean +/- standard deviation] nmol per h per 10(6) viable cells) and, to a lesser extent, glucose (139.63 +/- 11.52 nmol per h per 10(6) viable cells). Metabolism of these substrates in Caco-2/TC-7 cells resembled that in rat, pig, or human enterocytes. Infection by S. typhimurium C53-enhanced glucose and glutamine substrate utilization by 32 and 22%, respectively and enhanced glucose and glutamine substrate oxidation by eight- and twofold, respectively. These increases in glucose and glutamine metabolism (especially glucose metabolism) were due in part to the metabolism of intracellular bacteria and/or to the activation of cellular metabolism. Substrate metabolism (especially glucose metabolism) in C53-infected cells was partially reduced by treatment with ofloxacin. It was concluded that cellular fuel metabolism is stimulated at the earliest stage of infection (3 to 4 h) and that treatment with 5 mM ofloxacin does not completely restore substrate metabolism to the levels observed in uninfected cells, possibly because this treatment does not eradicate intracellular S. typhimurium completely.

Anti-Infective Agents↗

PubMed1998

Influence of renal failure on ciprofloxacin pharmacokinetics in rats.

Ciprofloxacin pharmacokinetics have been shown to be modified in patients with renal failure (e.g., the intestinal secretion of ciprofloxacin is increased). This study investigated the influence of renal failure on the pharmacokinetics of ciprofloxacin following oral and parenteral administration to rats of a dose of 50 mg/kg of body weight. After parenteral administration, only renal clearance (CLR) was reduced in nephrectomized rats (5.3+/-1.4 versus 17.8+/-4.7 ml/min/kg, P < 0.01, nephrectomized versus control rats). However, nonrenal clearance was increased in nephrectomized rats (32+/-4 versus 15+/-5 ml/min/kg, P < 0.01, nephrectomized versus control rats), suggesting compensatory mechanisms for reduced renal function. After oral administration, apparent total clearance and CLR were reduced (P < 0.01) in nephrectomized rats (117+/-25 and 6.8+/-4.4 ml/min/kg, respectively) compared with the values for control rats (185+/-9 and 22.6+/-5.3 ml/min/kg, respectively) and the area under the concentration-time curve was higher (P < 0.01) for nephrectomized rats (436.3+/-90.5 mg. min/liter) than for control rats (271.3+/-14.3 mg.min/liter). Terminal elimination half lives in the two groups remained constant after oral and parenteral administration. These results suggest an increased bioavailability of ciprofloxacin in nephrectomized rats, which was confirmed by a nonlinear mixed-effect model.

Administration, Oral↗

PubMed1998

Critical importance of in vivo amoxicillin and cefotaxime concentrations for synergy in treatment of experimental Enterococcus faecalis endocarditis.

The synergy between amoxicillin and cefotaxime against two strains of Enterococcus faecalis (JH2-2 and 6370) in vitro and in rabbit endocarditis was investigated. In vitro synergy was obtained only when amoxicillin concentrations were below the MBC and when cefotaxime concentrations were above 1 microg/ml. No synergy was observed in vivo, because of the short period of time during which these pharmacologic requirements were achieved.

Amoxicillin↗