TRENDS IN ANTIBIOTIC-RESISTANCE OF RESPIRATORY PATHOGENS - AN ANALYSIS AND COMMENTARY ON A COLLABORATIVE SURVEILLANCE STUDY

The evolution of antibiotic resistance was studied among common respir atory tract pathogens in five countries of the European Union and in t he USA during 1992-1993. The data obtained from a collaborative survei llance study were submitted to population analysis, to detect possible shifts in antibiotic susceptibility and, therefore, associated mechan isms of resistance. Among the emerging Haemophilus influenzae phenotyp es were isolates that did not correspond to the beta-lactamase negativ e, amino-penicillin resistant (BLNAR) phenotype, but were beta-lactama se producers showing low level ceftriaxone resistance (early extended spectrum beta-lactamases?) amoxycillin susceptible strains with low le vel ceftriaxone resistance (PBP modification?) and isolates with high- level fluoroquinolone resistance. Moraxella catarrhalis resistance to ceftriaxone erythromycin or fluoroquinolones was noted. The quantitati ve evolution of antibiotic resistance may reach saturation in some cou ntries with a very high proportion of resistant strains, for example, Spain and France. Qualitatively, resistant strains may be selected tha t have broader or more effective mechanisms of resistance, particularl y under the recently introduced pressure of more active antibiotics of the same family. In countries with modest levels of antibiotic resist ance (UK, Germany, Italy), attention should be paid to the misuse of a ntibiotics with a propensity to select low-level resistant strains. In this respect, the relative prescribing of aminopenicillins and oral c ephalosporins in the UK (a high ratio and low prevalence of Streptococ cus pneumoniae) and resistance to penicillin in the USA (a low ratio a nd high prevalence of resistance) is of potential importance.