Cefoxitin-Empfindlichkeit pathogener aerober und anaerober Aktinomyzeten

[Antibiotic resistance of anaerobic bacteria (author's transl)]

Reference data on the overall resistance patterns of anaerobic bacteria are needed since in individual clinical cases susceptibility testing is complicated by the long generation time and difficulties of test conditions. Benzylpenicillin and tetracyclines are the drugs of choice against Clostridium perfringens. Newer cephalosporins are also active, whereas other Clostridium species have been found resistant. Beta-lactam antibiotics show high activity against Peptococcaceae; resistance to clindamycin should be noted, however. The good in vitro activity of tetracyclines, clindamycin and erythromycin against Propionibacterium acnes could be confirmed in the systemic and local therapy of acne vulgaris. In contrast to gram-positive anaerobic bacteria, only some penicillin and cephalosporin derivatives are sufficiently active against gram-negative rods of the Bacteroides group. Sporadic resistance is seen to the newer tetrayclines, nitroimidazole compounds and to lincomycins. Nevertheless, these substances must be considered as standard therapeutics for infections caused by anaerobic gram-negative bacteria. It should be mentioned that cefoxitin may offer new therapeutic possibilities.

Special methodological problems in antibiotic susceptibility testing of fermentative actinomycetes

Knowledge on the antibiotic suceptibility of pathogenic fermentative actinomycetes is still fragmentary and contradictory, which is one reason why even today the chemotherapy of human actinomycosis may still present problems. Complete and reliable data on the in vitro sensitivity of these pathogens can be obtained, however, when standardized and specially adapted methods of susceptibility testing are employed. Special adaptation should cover the general technique of in vitro testing, as well as the choice of test media, the preparation of inocula, incubation methods and method of reading results. Provided that all factors are taken into account which might cause difficulties in test reproducibility and therapeutic relevance of the results, in vitro tests appear to contribute to the revision and updating of treatment regimes for actinomycosis. Our findings indicate that, apart from ampicillin the clinical efficacy of which has already often been proved, mezlocillin, cefoxitin, clindamycin, tetracyclines, rifampicin and erythromycin may be recommended as alternative drugs which would seem to offer good chances of success.