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Biomolecular recognition of vancomycin antibiotics with its cell-wall precursor analogue Ac(2)(L)K(D)A(D)A has been investigated in the gas phase through a combined laser spectroscopy/mass spectrometry approach. The mid-IR spectra (1100-1800 cm(-1)) of these mass-selected anionic species have been recorded by means of resonant infrared multiphoton dissociation (IRMPD) spectroscopy performed with the free-electron laser CLIO. Structural assignment has been achieved through comparisons with the low-energy conformers obtained from replica-exchange molecular dynamics simulations, for which IR spectra were calculated using a hybrid quantum mechanics/semi-empirical (QM/SE) method at the DFT/B3LYP/6-31+G*/AM1 level. Comparison between deprotonated vancomycin and its non-covalently bound V + Ac(2)(L)K(D)A(D)A complex shows significant spectral shifts of the carboxylate stretches and the Amide I and Amide II modes that are satisfactorily reproduced in the structures known from the condensed phase. Both theoretical and experimental findings provide strong evidence that the native structure of the deprotonated V + Ac(2)(L)K(D)A(D)A complex is preserved in the gas phase.

Introduction: Following their use for a few years, the place of new macrolides can be assessed., Current Knowledge and Key Points: "New macrolides", ie, roxithromycin, clarithromycin, azithromycin and dirithromycin, are derivated from erythromycin and defined by different pharmacokinetic parameters: longer half time with better oral administration and shorter duration of treatment, better tissue concentrations with reduction of dosages and better tolerance, high cellular concentration with good activity. However, new macrolides and erythromycin do not show major differences in their antibacterial spectrum against usual pyogenic strains. Clinical use of new macrolides extends to opportunistic infections, such as atypical mycobacterial infections or toxoplasmosis, occurring in the course of HIV infection. New macrolides are also recommended for the treatment of Helicobacter pylori-related gastroduodenal ulcer., Future Prospects and Projects: New macrolides have opened new avenues in the development of anti-infectious strategies. Due to their good efficacy against Chlamydia pneumoniae which is suspected of inducing vascular diseases, the upcoming use of ketolids and the development of their non-antibiotic effects, the future of macrolides is favorable.

The use of antibiotics in 480 cases in 4 hospital wards during 1988 was assessed by examination of medical records. Only the first antibiotic therapy administered during the first stay in the ward for each patient was included. Antibiotics were administered to 163 in-patients (37% of hospitalizations) for infections in 113 (26%) cases. Amoxycillin and macrolides were the drugs most frequently used. Sixty-eight percent of the treatments were administered in the absence of microbiological data. Single drug therapy was used in 60% of treatments. Fifty in-patients (11% overall; 41% of patients undergoing surgery) received antibiotics for prophylaxis. The exact indication(s) for the choice of therapy was not given in the medical records of 39% of cases. Treatment started within 48 hours of infection in 15% of the cases. Overall, 93% of the treatments given were indicated, but 53% were inappropriate because they were too expensive, unlikely to be effective or were multiple drug therapy without justification. There are a variety of factors that cause such inappropriate administration of antibiotics.