Temporal trends in prevalence of bacteria isolated from foals with sepsis: 1979-2010

• Published in: Equine veterinary journal Vol. 46; no. 2; pp. 169 - 173
• Main Authors: Theelen, M. J. P., Wilson, W. D., Edman, J. M., Magdesian, K. G., Kass, P. H.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-03-2014; Wiley Subscription Services, Inc
• Subjects: Animals; Animals, Newborn; Antimicrobial agents; Bacteria; Bacterial Infections - microbiology; Bacterial Infections - veterinary; Bacteriology; Enterococcus spp; Gram-negative bacteria; Gram-positive bacteria; horse; Horse Diseases - microbiology; Horses; neonatology; Retrospective Studies; Sepsis; Time Factors; Trends; horse; Gram-positive bacteria; neonatology; Gram-negative bacteria; Enterococcus spp; sepsis
• ISSN: 0425-1644; 2042-3306
• DOI: 10.1111/evj.12131

Summary
Reasons for performing study
Sepsis is an important cause of death in foals. Knowledge of which pathogens are likely to be involved is important for selection of antimicrobial drugs for initial treatment.
Objectives
To identify temporal trends in prevalence of bacteria isolated from foals with sepsis between 1979 and 2010.
Study design
Retrospective review of medical records.
Methods
All foals ≤30 days of age presented to the Veterinary Medical Teaching Hospital (VMTH) at the University of California, Davis between 1979 and 2010, with a diagnosis of sepsis confirmed by culture of bacteria from blood or internal organs (antemortem or at necropsy), were included in the study. Conventional microbiological methods were used to identify isolated organisms. The Cochran–Armitage trend test was used for statistical analysis.
Results
The percentage of Gram‐positive isolates increased significantly over the years. The percentage Enterobacteriacea, and Klebsiella spp. in particular, decreased over time. Enterococcus spp. isolates were cultured more often in recent years.
Conclusions
Whereas Gram‐negative bacteria, particularly Enterobacteriaceae, remain the most common isolates from neonatal foals with sepsis, the prevalence of Gram‐positive bacteria is increasing. This trend underlines the importance of including antimicrobial drugs active against both Gram‐positive and Gram‐negative bacteria in treatment protocols while awaiting the results of bacteriological culture and susceptibility tests. The increased prevalence of Enterococcus spp. is of concern because antimicrobial susceptibility patterns for enterococci are unpredictable and enterococci can also act as donors of antimicrobial resistance genes to other bacteria.