Antimicrobial susceptibility patterns and resistance transferability among Bacteroides fragilis group isolates from patients with appendicitis in Bali, Indonesia

Longitudinal study of susceptibilities of species of the Bacteroides fragilis group to five antimicrobial agents in three medical centers

A total of 579 clinical isolates of the Bacteroides fragilis group collected from three Canadian hospitals were tested for susceptibility to five antimicrobial agents by using an agar dilution method. During the 4-year survey, isolates from intra-abdominal infections were collected from the following sites: abdominal abscesses (48%), peritoneal fluid (39%), blood (10%), and bile (3%). B. fragilis was the most prevalent species (35.4%), followed by B. thetaiotaomicron (19.2%), B. ovatus (15.9%), and B. vulgatus (11%). No metronidazole- or imipenem-resistant strains were found during the survey. Resistance profiles varied among the different species tested: 7.8, 2.9, and 7.3% of B. fragilis strains (n = 205) and 68.1, 17.2, and 9.4% of non-B. fragilis strains (n = 373) were resistant to cefotetan, cefoxitin, and clindamycin, respectively. B. fragilis and B. vulgatus demonstrated lower resistance rates than B. thetaiotaomicron, B. ovatus, B. distasonis, and B. caccae. During the study, rates of resistance to cefotetan and clindamycin fluctuated but rates of resistance to cefoxitin increased, particularly at one center. These data indicate a need to determine the susceptibility patterns of the B. fragilis group periodically at each hospital.

Antimicrobial resistance patterns in Korea

Recent in-vitro test results showed that in Seoul (Korea) aerobic Gram-negative bacilli are often resistant to ampicillin and to the first-generation cephalosporins, but chloramphenicol-resistant Salmonella typhi are extremely rare. Almost all isolates of Moraxella (Branhamella) catarrhalis, 49% of Neisseria gonorrhoeae and 31% of Haemophilus influenzae were beta-lactamase producers. Seventhy-two percent of pneumococci were penicillin G resistant and 62% of staphylococci were methicillin resistant. Among the Enterococcus faecium, 59% were resistant to high-level gentamicin, but glycopeptide-resistant isolates were not found. Thirty-eight percent and 5% of Bacteroides fragilis were resistant to clindamycin and cefoxitin, respectively. In conclusion, antimicrobial-resistant bacteria are prevalent in Korea.