Temporal trends in in vitro antimicrobial susceptibility patterns of bacteria isolated from foals with sepsis: 1979–2010. (11th September 2013)

• Record Type: Journal Article
• Authors: Theelen, M. J. P.; Wilson, W. D.; Edman, J. M.; Magdesian, K. G.; Kass, P. H.
• Is Part Of: Equine veterinary journal. Volume 46:Number 2(2014:Mar.)
• Page Start: 161
• Page End: 168
• Publication Date: 2013-09-11
• Subjects: Horses -- Diseases -- Periodicals; 636.108905
• DOI: 10.1111/evj.12130
• Languages: English
• ISSNs: 0425-1644

Abstract

<abstract abstract-type="main"> <title>Summary</title> <sec id="evj12130-sec-0001" sec-type="section"> <title>Reasons for performing the study</title> <p>Monitoring the development of antimicrobial resistance is important for the rational selection of appropriate antimicrobial drugs to initiate treatment of foals with sepsis.</p> </sec> <sec id="evj12130-sec-0002" sec-type="section"> <title>Objectives</title> <p>To identify temporal trends in antimicrobial susceptibility patterns of bacteria isolated from foals with sepsis.</p> </sec> <sec id="evj12130-sec-0003" sec-type="section"> <title>Study design</title> <p>Retrospective review of medical records.</p> </sec> <sec id="evj12130-sec-0004" sec-type="section"> <title>Methods</title> <p>Foals aged <30 days with a diagnosis of sepsis, confirmed by culture of bacteria, were included. Susceptibility data, expressed as minimum inhibitory concentrations (MICs) (MIC<sub>50</sub>, MIC<sub>90</sub>, MIC range) and percent of isolates that were susceptible to a particular antimicrobial drug, were compared for bacteria isolated from foals during 3 different time periods: 1979–1990, 1991–1997 and 1998–2010. The Cochran‐Armitage trend test and the Jonckheere‐Terpstra test were used for statistical analysis.</p> </sec> <sec id="evj12130-sec-0005" sec-type="section"> <title>Results</title> <p>A total of 1091 bacterial isolates were cultured from 588 foals. Enterobacteriaceae, <italic>Actinobacillus</italic> spp<italic>.</italic> and β‐haemolytic <italic>Streptococcus</italic> spp<italic>.</italic> showed a decrease in percent of isolates susceptible to gentamicin over time. Enterobacteriaceae, <italic>Actinobacillus</italic> spp<italic>.</italic> and β‐haemolytic <italic>Streptococcus</italic> spp. showed an increase in MIC values for amikacin. Enterobacteriaceae showed a decrease in percent of isolates susceptible to ceftiofur. <italic>Enterococcus</italic> spp<italic>.</italic> and <italic>Pseudomonas</italic> spp. showed increased MIC values to ceftiofur. Enterobacteriaceae showed increased MIC values to ceftizoxime. <italic>Enterococcus</italic> spp<italic>.</italic> became more resistant to imipenem and showed increased MIC values to ticarcillin/clavulanic acid. In contrast, several trends in increased susceptibility were also seen.</p> </sec> <sec id="evj12130-sec-0006" sec-type="section"> <title>Conclusions</title> <p>Based on these <italic>in vitro</italic> results, the combination of amikacin and ampicillin remains an appropriate choice for initiating treatment of sepsis in foals while awaiting culture and susceptibility test results, although increasing development of resistance to amikacin was demonstrated. The decrease in <italic>in vitro</italic> activity of ceftiofur against Enterobacteriaceae is of concern. Similarly, the development of resistance of <italic>Enterococcus</italic> spp. to imipenem is an important finding that warrants monitoring in the future. Judicious use of antimicrobials is therefore crucial.</p> </sec> </abstract>