Decline in antibiotic resistance and changes in the serotype distribution of Streptococcus pneumoniae isolates from children with acute otitis media; a 2001-2011 survey by the French Pneumococcal Network.

Streptococcus pneumoniae is an important cause of acute otitis media (AOM). The aim of this study was to evaluate trends in antibiotic resistance and circulating serotypes of pneumococci isolated from middle ear fluid of French children with AOM during the period 2001-2011, before and after the introduction of the PCV-7 (2003) and PCV-13 (2010) vaccines. Between 2001 and 2011 the French pneumococcal surveillance network analysed the antibiotic susceptibility of 6683 S. pneumoniae isolated from children with AOM, of which 1569 were serotyped. We observed a significant overall increase in antibiotic susceptibility. Respective resistance (I+R) rates in 2001 and 2011 were 76.9% and 57.3% for penicillin, 43.0% and 29.8% for amoxicillin, and 28.6% and 13.0% for cefotaxime. We also found a marked reduction in vaccine serotypes after PCV-7 implementation, from 63.0% in 2001 to 13.2% in 2011, while the incidence of the additional six serotypes included in PCV-13 increased during the same period, with a particularly high proportion of 19A isolates. The proportion of some non-PCV-13 serotypes also increased between 2001 and 2011, especially 15A and 23A. Before PCV-7 implementation, most (70.8%) penicillin non-susceptible pneumococci belonged to PCV-7 serotypes, whereas in 2011, 56.8% of penicillin non-susceptible pneumococci belonged to serotype 19A. Between 2001 and 2011, antibiotic resistance among pneumococci responsible for AOM in France fell markedly, and PCV-7 serotypes were replaced by non-PCV-7 serotypes, especially 19A. We are continuing to assess the impact of PCV-13, introduced in France in 2010, on pneumococcal serotype circulation and antibiotic resistance.

Biliary tract excretion of ofloxacin in man.

This study examined the biliary tract excretion of ofloxacin in 6 post-cholecystectomy patients with a T-tube inserted into the common duct (group A) and 6 patients during cholecystectomy (group B). The patients were given 7 oral doses of ofloxacin 200mg with a 12-hour interval between each dose. Blood and common duct bile samples were collected in group A at various time intervals after the first and the seventh dose. Blood, gallbladder wall, and gallbladder and common duct bile were collected in group B during operation, 6 hours after the seventh dose. Assays were performed by use of high performance liquid chromatography (HPLC). In group A, mean serum Cmax and half-life were 2.6 mg/L and 7.6 hours after the first dose, and 5.3 mg/L and 8 hours after the seventh dose, respectively. Mean common duct bile Cmax and half-life were 6.5 mg/L and 7.5 hours after the first dose, and 12.0 mg/L and 14 hours after the seventh dose, respectively. In group B, mean concentrations (mg/L) were 2.6 in blood, 5.3 in gallbladder wall, 24.6 in gallbladder bile and 10.1 in common duct bile, 6 hours after the seventh dose. These data suggest that ofloxacin may be suitable for the treatment of biliary tract infections.

Sulbactam: secondary mechanisms of action.

Light and scanning electron microscopy showed that 0.25, 0.5 and 1 times the minimum inhibitory concentrations (MICs) of sulbactam (SULB) caused filament formation in different species of Enterobacteriaceae, while 2 and 4 times the MICs caused spheroplast formation and subsequent lysis. By using a competitive assay with 125I-penicillin X, SULB showed a primary affinity for the PBP 1a and PBP3 of Escherichia coli, as well as for the PBP1a of Proteus mirabilis. The bactericidal interaction of human polymorphonuclear leukocytes (PMN) and SULB against E. coli K-1 resistant to the bactericidal activity of human serum was studied in vitro; however, SULB concentrations showed variations in the medium according to human kinetic data. Under these conditions, bacterial growth occurred in Hanks balanced salt solution containing SULB, PMN, or SULB-PMN in combination. In addition, bactericidal activity was observed in serum, with a killing rate of 90% for PMN or SULB, and 95% for SULB-PMN in combination. The postantibiotic enhancement of PMN bactericidal function was assessed against E. coli K1 pretreated with 0.5 the MIC of SULB (32 micrograms/ml) for 0.5 hr. The 90% bacterial killing rate of PMN occurred by 1.5 hr for pretreated bacteria and by 2.5 hr for untreated bacteria. Furthermore, the luminol-enhanced chemiluminescence (CL) assay using an E. coli stimulus showed that SULB does not modify PMN activity.

The ocular penetration of oral sparfloxacin in humans.

The penetration of sparfloxacin into the aqueous humor after oral administration was studied in 28 patients undergoing cataract surgery. Each patient received a single, oral dose of 400 mg of sparfloxacin. In eight other patients scheduled to undergo vitreal surgery, multiple daily oral doses were administered for a total amount of 1,000 mg. The aqueous levels were (mean +/- SEM) 0.127 +/- 0.036 microgram/ml to 0.404 +/- 0.159 microgram/ml from two to 24 hours after ingestion. In the vitreous, the mean drug level was 0.840 microgram/ml (range, 0.480 to 2.060 microgram/ml), from 4.3 to 8.0 hours after the most recent oral dose. Blood samples obtained at the same time as vitreous and aqueous taps were assayed by high-performance liquid chromatography. These data demonstrate that therapeutic levels of sparfloxacin may be achieved in noninflamed, noninfected eyes undergoing cataract or vitreous surgery.

Differences between clavulanic acid and sulbactam in induction and inhibition of cephalosporinases in enterobacteria.

The ability of clavulanic acid and sulbactam to induce and inhibit cephalosporinases was evaluated in 16 clinical isolates of enterobacteria. Using the quantitative induction assay, the checkerboard method and the disc approximation test, clavulanic acid was shown to act as inducer for all species, whereas sulbactam only induced strains of Providencia stuartii. Antagonism was achieved using a combination of clavulanic acid and cefotaxime but a combination of sulbactam and cefotaxime was either synergistic or indifferent. This variation in effect was probably due to the fact that sulbactam, but not clavulanic acid could inhibit cephalosporinases. The data revealed a significant difference between sulbactam and clavulanic acid, which may have relevance to their relative usefulness in combination with beta-lactam antibiotics for the treatment of infections due to enterobacteria that produce inducible cephalosporinase.

[Pneumococcal antibiotic resistance. Data from 6 regional registries for 1999]. / Résistance du pneumocoque aux antibiotiques. Données de 6 observatoires régionaux pour l'année 1999.

RESISTANCE BY REGION: Resistance varied greatly by region, ranging from 34.2% resistant strains in Alsace to 63.1% in Brittany. The incidence of resistant strains was always higher in children (especially in children aged 1 to 5 years) and in ENT samples. The time course of resistance has varied between regions, as has that of serotypes. CRUCIAL FINDING: In these 6 regions, and despite a high incidence (that varied from one region to another) of reduced susceptibility strains for penicillin G, amoxicillin (19-32%) and cefotaxime (6.5-18.5%), amoxicillin-cefotaxime resistant strains remained very rare (0.2-3.5%).

[Pharmacokinetics of dextromoramide in the surgical patient]. / Pharmacocinétique du dextromoramide chez l'opéré.

The pharmacokinetics of dextromoramide were studied in nine patients undergoing peripheral vascular surgery. All the patients were anaesthetised with thiopentone and vecuronium. After tracheal intubation, anaesthesia was maintained with 0.5 to 1.5 vol % halothane and a 60%-40% vol nitrous oxide-oxygen mixture. Once the patient's status was stable, a 0.8 mg.kg-1 bolus of dextromoramide was given intravenously. Blood samples were obtained 2, 5, 10, 30, 60, 90, 120, 180, 240, 300, 360, and 420 min afterwards by an arterial catheter. Dextromoramide serum concentrations were measured with high performance liquid chromatography after extraction with an original technique. The pharmacokinetic parameters were calculated by computer using TRIOMPHE. In five patients, a bi-exponential equation best fitted the results, whereas a tri-exponential equation was necessary for the other four. Mean elimination half-life was 215.3 +/- 78.4 min, and the apparent final volume of distribution was 0.58 +/- 0.20 l.kg-1. Hepatic extraction was low, as shown by a mean systemic clearance of 2.0 +/- 0.9 ml.kg-1.min-1. Liposolubility of this drug is the highest of all opiates, with a heptane/water partition coefficient of 12.3. These parameters demonstrate that, in the opiate drug group, dextromoramide has a place apart from the others.

In vitro combinations of five intravenous antibiotics with dalfopristin-quinupristin against Staphylococcus aureus in a 3-dimensional model.

We compared the in vitro activity of dalfopristin and quinupristin combined with five intravenous antibiotics in a 3-dimensional model. We tested six strains of Staphylococcus aureus selected with different patterns of resistance to methicillin and erythromycin. Dalfopristin and quinupristin displayed a very synergistic activity against all the strains with a mean 16- or 32-fold decrease of inhibitory concentrations in combination. That synergy was even better against erythromycin-resistant strains. In combination with tigecycline or fosfomycin, the antibacterial activity could be consistently enhanced with the same decrease of inhibitory concentrations. A synergy was also observed, less regularly and at a lower level, with rifampin, gentamicin or vancomycin. Combinations of dalfopristin and quinupristin with tigecycline or fosfomycin could be very interesting in clinical practice because the inhibitory effect could be achieved with very low concentrations of each component, even when erythromycin-resistant strains are concerned.

Acute postoperative endophthalmitis caused by Staphylococcus lugdunensis.

Acute postoperative endophthalmitis caused by Staphylococcus lugdunensis is infrequently reported in clinical studies. Five cases of acute postcataract surgery endophthalmitis caused by S. lugdunensis were taken from a multicenter prospective study conducted in four university-affiliated hospitals in France (2004 to 2005). These cases were characterized by severe ocular inflammation occurring with a mean delay of 7.6 days after cataract surgery, severe visual loss (hand motions or less in three cases), and dense infiltration of the vitreous. Each of these patients was initially treated by using a standard protocol with intravitreal (vancomycin and ceftazidime), systemic, and topical antibiotics. Given the severity of the endophthalmitis, even though bacteria were sensitive to intravitreal antibiotics, pars plana vitrectomy was needed in four cases. The final visual prognosis was complicated by severe retinal detachment in three cases. The microbiological diagnosis was reached by using conventional cultures with specific biochemical tests and eubacterial PCR amplification followed by direct sequencing.

Presumed pseudobacteremia outbreak resulting from contamination of proportional disinfectant dispenser.

Reported here are the microbiological and epidemiological details of a presumed outbreak of aerobic gram-negative bacilli infections affecting 19 hematological patients, which was traced to contaminated disinfectant. Over a 5-month period, the following organisms were isolated from the blood cultures of 19 neutropenic patients: Pseudomonas fluorescens (n = 13), Achromobacter xylosoxidans (n = 12), Comamonas testosteroni (n = 2) or Stenotrophomonas maltophilia (n = 1). The affected patients were all treated with an expensive regimen of broad-spectrum antibiotic therapy. The same bacteria were recovered from environmental samples as well as from the water pipes of an apparatus for dispensing disinfectant (didecyldimethylammonium chloride). Genotyping results indicated that many of the clinical strains were identical to strains isolated from the apparatus. It was eventually discovered that the night staff was in the habit of disinfecting the blood-culture bottles before use, thereby contaminating the bottles with bacteria contained in the disinfectant. Contamination of the apparatus resulted from faulty maintenance.

[Modulatory effect of antimicrobial agents or aminoacids on the oxidative burst of polymorphonuclear neutrophils triggered by formylmethionyl-leucyl-phenylalanine (fMLP)]. / Influence des antibiotiques et des acides aminés sur la réaction oxydative des polynucléaires neutrophiles déclenchée par la formylméthionyl-leucyl-phénylalanine (fMLP).

We have compared the interplay of several antimicrobial agents and aminoacids on the neutrophil respiratory burst in response to formylmethionyl-leucyl-phenylalanine (fMLP), a chemoattractant. Mainly, an inhibitory effect has been observed in the penicillin family of agents and an enhancing effect in the cephalosporin family of agents. The molecules in which the sulfur numbered 1 in the 6-APA or 7-ACA nucleus was replaced by a carbon or an oxygen, had a different effect as compared with the other members of the family. The modulatory effects of ampicillin and cephalothine were not significant at a concentration lower than 10 mg/l and the effect of cephalothine looked maximum at 20-40 mg/l. If studies in cell-free systems demonstrated that the inhibitory effect of some antimicrobials could be due to a direct oxidant-scavenger activity mainly of HOCl, only hypotheses are proposed to explain the enhancing activity of the others. It could be in relation with (i) a synergistic effect upon fMLP receptor leading to an increase in H(2)O(2)/HOCl production or (ii) the generation of new oxydant products originating in cephalosporin lysis under HOCl attack, which would be able to react with luminol. The interplay of antimicrobial agents with the respiratory burst measured outside the cells probably has no therapeutic consequences because the bactericidal activity of neutrophils is achieved inside phagosomes where few agents are known to come into and where chemical conditions are different. On the opposite, in clinical use, this interplay could be interesting to study for a prevention of side effects.

Cytotoxicity and uptake of pefloxacin, ciprofloxacin, and ofloxacin in primary cultures of rat hepatocytes.

The cytotoxicity and the uptake of three 4-quinolones--pefloxacin, ciprofloxacin, and ofloxacin--were investigated in primary cultures of rat hepatocytes. As assessed by intracellular enzyme release in culture media, pefloxacin at concentration 400 mg/l and ciprofloxacin at 200 mg/l were found to be hepatotoxins. However, concentration ofloxacin up to 400 mg/l were not hepatotoxic. After 48 h incubation, the remaining antibiotic concentrations in the culture medium as determined by HPLC were 55%, 45%, and 35% for ofloxacin, ciprofloxacin, and pefloxacin, respectively. Comparisons of quinolone concentrations in the hepatocyte culture medium determined by HPLC and correspondent antibacterial activities determined by microbiological assays did not reveal any metabolites with antibacterial activity other than those which have been identified from intact animals.

[Bronchopulmonary lymphocytes and their B and T subpopulations in control and experimental influenza infected mice]. / Lymphocytes bronchopulmonaires et leurs sous-populations B et T chez des souris normales et des souris soumises à une grippe expérimentale.

Immunofluorescent studies showed that, whereas the total number of lymphocytes was still increased on the third and fourth weeks of experimental airborne influenza, the B/T cell ratio remained in the same range as in control animals. This ratio is comparable to results with mouse peripheral lymph nodes.

Myocarditis due to Salmonella virchow and sudden infant death.

A strain of Salmonella virchow was isolated in the myocardium of a 1 1/2 month child who died suddenly. The source of contamination was the water of a family aquarium containing turtles.

[Comparative value of complement fixation and indirect immunofluorescence reactions for the detection of Q fever]. / Valeur comparée des réactions de fixation du complément et d'immunofluorescence indirecte pour le dépistage de la fièvre Q.

1 052 serum samples from 1 013 persons living in rural areas, were tested by IF and CF; with the IF-test, 4% of them were sero-positive (titer greater than or equal to: 20). IF-tests are eightfold more sensitive than CF tests and have at least the same specificity. The results of two (commercial) Coxiella burnetii phase II antigens were compared.

Ocular penetration of topically applied norfloxacin 0.3% in the rabbits and in humans.

The kinetics of topically applied norfloxacin 0.3 percent were studied in rabbit and man. All measurements were performed by high-pressure liquid chromatography. Norfloxacin concentrations were investigated five to 120 minutes in rabbit ocular tissues after instillation of a single drop. In normal eyes, after 30 minutes, mean +/- SEM levels were 14.3 +/- 3.7 micrograms/g in cornea, 3.3 +/- 0.7 micrograms/g in conjunctiva, 0.2 +/- 0.1 microgram/g in aqueous humor. After removal of the corneal epithelium concentrations were as follows: 84.2 +/- 15.8 micrograms/g, 7.3 +/- 2.3 micrograms/g, 8.6 +/- 1.9 micrograms/g respectively. Penetration in posterior ocular tissues were rather poor. In human eyes, the intracorneal concentrations were assessed in patients being operated on corneal grafts. After instillation of 5 drops, the concentration in cornea was 15.5 +/- 2.1 micrograms/g. These data show that therapeutic levels of norfloxacin can be achieved in anterior ocular tissues, which may be of help in superficial infections of the eye.

Bactericidal activity of cefodizime on Enterobacteriaceae in an in-vitro model simulating plasma pharmacokinetics in humans.

An in-vitro dialysis model was employed to assess the feasibility of once-daily dosing of cefodizime in the treatment of infections caused by various Enterobacteriaceae: Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Serratia marcescens, Providencia stuartii and Enterobacter cloacae. This model simulated the concentrations of cefodizime detected in human blood after an intravenous (i.v.) bolus injection of 1 g or 2 g of the antibiotic. Validation of the model was undertaken to confirm its utility. Based on the data obtained with this model, once-daily dosing with 1 g cefodizime (i.v.) should be effective against infections due to the commonest Gram-negative bacteria (E. coli, K. pneumoniae, M. morganii). For infections caused by Enterobacteriaceae strains that produce large quantities of Class I beta-lactamases, twice-daily (P. stuartii or S. marcescens) or four times daily (E. cloacae) administration of 1 g cefodizime may be required.

[Bactericidal activity of amoxicillin and cefaclor in an "in vitro" kinetic model (author's transl)]. / Activité bactéricide de l'amoxicilline et du céfaclor in vitro en fonction de la variation des concentrations sériques d'antibiotique observées chez l'homme.

The bactericidal activity against Staphylococcus aureus 290-P, Escherichia coli NIHJ-JC2 and Klebsiella pneumoniae ATCC-10031 (10(6)/ml) was studied during 24 h, using an in vitro kinetic model which simulates the drug concentrations occurring in human serum after oral doses of amoxicillin (0.5 g or 1 g) or cefaclor (0.25 g or 0.50 g), 2 or 3 times a day. After the first antibiotic exposure, a high level of bactericidal activity (99-99.9%) was observed. Complete bactericidal activity was observed in all cases against S. aureus, but only after 3 times per day exposures in the case of E. coli and K. pneumoniae. Twice per day exposures of amoxicillin or cefaclor were invariably ineffective for these two species of Enterobacteriaceae (10(9) bacterial survivors/ml). These findings were related to subinhibitory concentrations which were or not able to prevent or reduce the bacterial regrowth after the first exposure of the antibiotics.