Effect of ceftobiprole on the normal human intestinal microflora

Abstract number: P1226

Panagiotidis G., Bäckström T., Asker-Hagelberg C., Rashid M., Weintraub A., Nord C.E.

Objectives: Administration of antimicrobial agents to patients can cause modifications of the normal microflora. Consequent reduction in the colonization resistance leading to overgrowth of new or already present microorganisms has been described. Increased resistance in many Gram-positive bacteria has driven the need to develop new antibacterial agents with activity against these pathogens including methicillin resistant Staphylococcus aureus (MRSA). Ceftobiprole is a new broad spectrum pyrrolidinone cephem active against S. aureus (MRSA and MSSA), vancomycin-resistant Enterococcus faecalis and Gram-negative bacteria such as Enterobacteriaceae and Pseudomonas spp. The purpose of the present study was to investigate the effect of administration of ceftobiprole on the normal intestinal microflora of healthy subjects.

Methods: Twelve healthy subjects (6 males and 6 females) 20–41 years of age received ceftobiprole 500 mg by intravenous infusion q8 h during 7 days. Plasma and faeces were collected on days 1, 4, 7, 10, 14 and 21 for determination of concentration by biological and chemical methods. For analysis of the microflora, the faecal specimens were cultured on non-selective and selective media. Different colony types were counted, isolated in pure culture, and identified to genus level. All new colonizing aerobic and anaerobic bacteria were tested for susceptibility to ceftobiprole.

Results: The plasma concentrations of ceftobiprole were as follows: On day 1, 14.7–23.6 mg/l; on day 4, 15.9–24.5 mg/l; and on day 7, 15.9–23.9 mg/l. No ceftobiprole was detected in plasma on days 10, 14 and 21. No measurable concentrations were found in faeces on days 1, 4, 7, 10, 14 and 21. There were minor changes in the numbers of enterobacteria, enterococci and Candida albicans, and there were moderate changes on numbers of bifidobacteria, lactobacilli, clostridia and bacteroides during the same period. No Clostridium difficile strains or toxins were found. No new colonizing aerobic and anaerobic bacteria with ceftobiprole minimum inhibitory concentrations of >4 mg/l were found.

Conclusion: Ceftobiprole had no significant ecological impact on the human intestinal microflora of healthy volunteers.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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