PERSPECTIVE ON SUSCEPTIBILITY TESTING OF ANAEROBIC-BACTERIA

Physicians must use empirical treatment initially for anaerobic infect ions, However, such treatment can be targeted if clinicians establish the nature of the infection and know the usual infecting flora of that type of infection and how the flora may have been modified by the use of antimicrobials. Physicians must also be aware of the usual suscept ibility patterns of various anaerobes and nonanaerobes in the hospital s in which they work, Despite cost containment, it is still important to isolate all anaerobes present, to provide at least general identifi cation (and specific identification of key organisms such as the Bacte roides fragilis group), and to keep the organisms alive so that they m ay be referred elsewhere for definitive identification and susceptibil ity testing, if indicated. Because resistance is increasing among anae robes, susceptibility testing is very important. Susceptibility testin g should be done when patients are seriously ill, when patients do not respond to therapy or relapse, when there are few data available on a species, when the organisms isolated are frequently resistant, and wh en patients require prolonged therapy, Periodic surveys of susceptibil ity patterns should be done on isolates from individual hospitals, Tes ts most useful for individual patient isolates are the Etest (AB BIODI SK, Solna, Sweden), an expensive test, and the microbroth dilution tes t. Testing should be done on organisms that are the most virulent and most resistant to antimicrobial agents.