Surveillance study of the susceptibility of Haemophilus influenzae to various antibacterial agents in Europe and Canada.

BACKGROUND: Haemophilus influenzae is a major respiratory tract pathogen that is becoming increasingly resistant to beta-lactam antibiotics. MATERIALS AND METHODS: Using a microdilution method performed to Clinical and Laboratory Standards Institute (CLSI) guidelines, we determined the minimal inhibitory concentrations (MICs) of various antibacterial agents against 536 isolates of H. influenzae. The isolates were obtained from patients with respiratory tract infections being treated in 18 European and two Canadian centres between 2006 and 2007. RESULTS: Levofloxacin, moxifloxacin, cefixime and cefpodoxime with MIC(90) values of < or = 0.03, < or = 0.03, 0.03 and 0.06 g/mL, respectively, were the four most active agents tested. Overall, amoxicillin resistance was observed in 25.0% of the strains, but was generally reversed with the addition of clavulanic acid. In 73 strains (13.6%) resistance was due to beta-lactamase (BL) production while the remainder (n = 61; 11.4%) were BL-negative, amoxicillin-resistant (BLNAR) strains. Comparison of penicillin binding protein 3B sequences in BLNAR isolates revealed that only mutations at amino acids 502 (alanine [Ala] --> threonine [Thr]/valine [Val]) and 526 (asparagine [Asn] --> lysine [Lys]) were significantly associated with amoxicillin resistance among European H. influenzae isolates (p < 0.0001 for both). CONCLUSIONS: This surveillance study highlights an increased prevalence of amoxicillin-resistant strains of H. influenzae compared with a previous study that we performed in 2004/2005. The third-generation cephalosporins cefixime and cefpodoxime, as well as amoxicillin plus clavulanic acid, continue to be very active against both BL-positive and BLNAR strains of H. influenzae, and thus remain useful treatment options for patients with respiratory tract infections.

In vitro activity of AR-709 against Streptococcus pneumoniae.

We investigated the in vitro activity of AR-709, a novel diaminopyrimidine antibiotic currently in development for treatment of community-acquired upper and lower respiratory tract infections, against 151 Streptococcus pneumoniae strains from various European countries. AR-709 showed excellent activity against both drug-susceptible and multidrug-resistant pneumococci.

In vitro activity of telavancin against gram-positive clinical isolates recently obtained in Europe.

The in vitro activity of telavancin was tested against 620 gram-positive isolates. For staphylococci, MICs at which 50 and 90% of isolates were inhibited (MIC(50) and MIC(90)) were both 0.25 microg/ml, irrespective of methicillin resistance. MIC(50) and MIC(90) were 0.25 and 0.5 microg/ml for vancomycin-susceptible enterococci and 1 and 2 microg/ml for vancomycin-resistant enterococci, respectively. Streptococcus pneumoniae, group A and B beta-hemolytic streptococci, and viridans streptococci were inhibited by < or =0.12 microg/ml.

Longitudinal European surveillance study of antibiotic resistance of Haemophilus influenzae.

OBJECTIVES: We assessed the current resistance rates of Haemophilus influenzae against beta-lactams and other agents in Europe and compared the results with those of our previously performed surveillance study. METHODS: MICs of the antibiotics were determined using broth microdilution. The penicillin-binding domain of PBP3 of beta-lactamase (BL)-negative, amoxicillin-resistant (BLNAR) isolates was sequenced. RESULTS: The percentage of BL-positive and BLNAR strains ranged from 0% to 17.6% and 0% to 33.9%, respectively. Compared with 1997/98 and 2002/03, the overall percentage of strains non-susceptible to amoxicillin decreased from 19.8% and 23.3%, respectively, to 16.4% in 2004/05. The percentage of BL-producing strains decreased from 11.0% and 13.7%, respectively, to 7.6%, whereas the number of BLNAR strains remained stable (8.8% and 9.6%, respectively, versus 8.8% in 2004/05). Comparison of penicillin binding protein (PBP) 3B gene sequences between BLNAR and susceptible strains revealed novel amino acid mutations. CONCLUSIONS: In spite of large inter-regional differences, the overall resistance of H. influenzae to amoxicillin in Europe seems to decline due to a decreasing number of BL-producing strains, whereas the overall percentage of BLNAR strains seems relatively constant.

In vitro and in vivo digestibility and metabolic effects of 3 wheat-flour products (white bread, french toast (rusk) and french toast bran-enriched) in normal subjects.

We devised to study the effects of two technological processings of industrial bread (degree of cooking and enrichment with bran) on in vitro digestibility and repercussions on carbohydrate metabolism in healthy subjects. 3 products were tested in vitro and in vivo: white bread (WB), french toast obtained from the same white bread (FT) and french toast enriched with bran (BFT). In vitro, the percentage of starch hydrolysed was significantly lower for the bran-enriched toast than for WB and FT (p less than 0.001). In vivo, the 3 products and an oral glucose load were given at 08.00 h, after an overnight fast, to 12 healthy volunteers (8 F; 4 M); (age = 24 +/- 1 years; BMI = 21.9 +/- 0.9; mean +/- SEM) on four consecutive days and in random order (latin squares 3 x 4). Each meal contained 35 g carbohydrate and 125 ml water and, for the wheat products, about 190 Kcal. The mean results of the glycemic indexes were: WB = 115 +/- 17%; FT = 99 +/- 21%; BFT = 87 +/- 21% (NS) with the corresponding insulin indexes at 81 +/- 8%, 79 +/- 9% and 90 +/- 8% respectively (NS). The mean plasma glucose and insulin values at 30 minutes did not differ between the three tested foods but were all significantly lower than that observed with glucose (p less than 0.01). Plasma glucose transiently descended below baseline values in all subjects for glucose and BFT. Neither the toasting process nor the presence of wheat bran had any major effect upon hyperglycemia and insulin secretion in the healthy subjects studied.

Characterization and distribution of soluble and insoluble carbohydrates in lupin seeds.

White, blue and yellow lupin seeds were analyzed for their soluble and insoluble carbohydrate contents. The seeds contained only traces of starch. Their furfural generator contents were fairly constant (9.3--10.5%) and their soluble sugar contents were in the range of 11.8 to 14.1%. Thin-layer and column chromatography of the ethanol-soluble sugars showed the presence of varying amounts of ajugose, verbascose, stachyose, raffinose and sucrose. Quantitative analysis revealed an average of 25% sucrose in the total sugars, the major part of which is composed of alpha-galactosides. Separate analysis of the cotyledons (including the germ) showed that the latter contain 80% total carbohydrates, most of which were structural polysaccharides. The composition of the cell-wall constituents was examined after acid hydrolysis. Monosaccharides resulting after acid hydrolysis of the hemicelluloses were predominantly xylose and arabinose. Smaller quantities of galactose and glucose, and traces of rhamnose were also present. The cotyledons contain a considerable amount of soluble sugars (19.0%). Small amounts of glucose-containing polymers, soluble in water and dilute acid, were present in the cotyledons (1.0%); they increased to 2.4% in the hulls.