Alyaseen, Samer A.

ABSTRACT Exposure of ciprofloxacin- and cefepime-susceptible Pseudomonas aeruginosa isolates to increasing concentrations of ciprofloxacin selected for ciprofloxacin resistance in 26/27 and cefepime nonsusceptibility in 7/27 isolates. Exposure of the isolates to increasing concentrations of cefepime selected for cefepime nonsusceptibility in 20/27 isolates but not for ciprofloxacin resistance.

ABSTRACT Studies that detected an association between Streptococcus bovis endocarditis and colon carcinoma have not taken into account the recently identified genetic diversity among organisms historically classified as S. bovis . With near full-length 16S ribosomal DNA sequence analysis, organisms cultured from the blood of endocarditis patients at the Mayo Clinic from 1975 to 1985 and previously identified as S. bovis or streptococcus group D nonenterococci were shown to represent S. bovis biotypes I (11 isolates) and II/2 (1 isolate), S. salivarius (1 isolate), and S. macedonicus (1 isolate). Two of the S. bovis biotype I cases were associated with colon cancer. Whether S. bovis biotype II or other organisms closely related to and historically identified as S. bovis (e.g., S. macedonicus ) are associated with malignant (or premalignant) colon lesions in humans remains to be definitively determined.