Document 0500
 DOCN  M9490500
 TI    Rifabutin and sparfloxacin but not azithromycin inhibit binding of
       Mycobacterium avium complex to HT-29 intestinal mucosal cells.
 DT    9411
 AU    Bermudez LE; Young LS; Inderlied CB; Kuzell Institute for Arthritis and
       Infectious Diseases,; California Pacific Medical Center Research
       Institute, San; Francisco 94115.
 SO    Antimicrob Agents Chemother. 1994 May;38(5):1200-2. Unique Identifier :
       AIDSLINE MED/94346836
 AB    Organisms of the Mycobacterium avium complex (MAC) cause disseminated
       disease in patients with AIDS, and evidence points to the
       gastrointestinal tract as the major route of infection. Since MAC can
       bind to and invade intestinal mucosal cells, we examined whether
       subinhibitory concentrations of antibiotics which have anti-MAC activity
       in vitro affect the interaction between MAC and HT-29 intestinal mucosal
       cells. MAC isolates were exposed to subinhibitory concentrations of
       rifabutin (MIC, 2.6 micrograms/ml), sparfloxacin (MIC, 8.4
       micrograms/ml), or azithromycin (MIC, 32 micrograms/ml) for 30 to 120
       min, washed, and incubated with HT-29 cell monolayers for 2 h at 4
       degrees C. HT-29 cell monolayers were then washed to remove unbound
       bacteria and were subsequently lysed. The number of MAC isolates that
       bound to the HT-29 cells was determined by plating the cell lysate onto
       7H10 agar. Preincubation of the MAC isolates with rifabutin at
       concentrations of 1 and 2 micrograms/ml reduced MAC binding to HT-29
       cells by 80 to 90%, while MAC exposed to sparfloxacin at 1 and 7
       micrograms/ml inhibited binding by 77 to 93%. Azithromycin at
       concentrations of 2, 10, and 30 micrograms/ml had no effect on MAC
       binding to HT-29 cells. Inhibition of MAC binding to the
       gastrointestinal mucosa may be one underlying mechanism for the
       prophylactic effects of rifabutin and quinolones.
 DE    Anti-Infective Agents, Fluoroquinolone/*PHARMACOLOGY
       Azithromycin/*PHARMACOLOGY  Bacterial Adhesion/*DRUG EFFECTS  Human
       Intestinal Mucosa/CYTOLOGY/*MICROBIOLOGY  Mycobacterium avium
       Complex/*DRUG EFFECTS  Mycobacterium avium-intracellulare
       Infection/MICROBIOLOGY  Quinolones/*PHARMACOLOGY
       Rifabutin/*PHARMACOLOGY  Tumor Cells, Cultured  JOURNAL ARTICLE

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