Catheter-tract infections in rhesus macaques (Macaca mulatta) with indwelling intravenous catheters

Development of catheter-tract infections in experimental animals can have devastating consequences on animal health and the functional lifespan of surgical implants. To measure the incidence of catheter-tract infections in animals with exteriorized intravenous catheters in this facility and assess the effects of these infections on mean catheter lifespan, health records of 31 Macaca mulatta with catheters were reviewed. Records spanned the interval of January 1, 1996 through October 1, 1997. Catheter-tract infections in 16 of 53 (30.2%) monkeys with catheters were diagnosed based on a combination of clinical signs of infection and results of bacterial culture. Segmental catheter-tract infections reduced mean catheter lifespan to 147 days, compared with 354 days for uninfected catheters. Exit-wound, local tunnel, and surgical-site infections did not significantly reduce catheter lifespan. Bacterial culture reports documented 31 isolates; 41.9% (13 of 31) were coagulase-negative staphylococci, and 22.6% (7 of 31) were Staphylococcus aureus. Of 20 isolates tested, 15 (75%) were resistant to methicillin/oxacillin in vitro. Antimicrobial susceptibility testing of methicillin-resistant and methicillin-susceptible isolates indicated that, compared with methicillin-sensitive isolates, methicillin-resistant isolates had a pattern of multiple antibiotic resistance. Catheter-tract infections were common in this colony of rhesus macaques, and clinically severe infections caused a drastic reduction in catheter lifespan. Approximately half (48%) the bacterial isolates were methicillin-resistant gram-positive bacteria.