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Temporal trends in in vitro antimicrobial susceptibility patterns of bacteria isolated from foals with sepsis: 1979–2010
Author(s) -
Theelen M. J. P.,
Wilson W. D.,
Edman J. M.,
Magdesian K. G.,
Kass P. H.
Publication year - 2014
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/evj.12130
Subject(s) - microbiology and biotechnology , amikacin , biology , antimicrobial , ceftiofur , gentamicin , ampicillin , imipenem , antibiotics , antibiotic resistance
Summary Reasons for performing the study Monitoring the development of antimicrobial resistance is important for the rational selection of appropriate antimicrobial drugs to initiate treatment of foals with sepsis. Objectives To identify temporal trends in antimicrobial susceptibility patterns of bacteria isolated from foals with sepsis. Study design Retrospective review of medical records. Methods 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 50 , MIC 90 , 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 C ochran‐ A rmitage trend test and the J onckheere‐ T erpstra test were used for statistical analysis. Results A total of 1091 bacterial isolates were cultured from 588 foals. E nterobacteriaceae, A ctinobacillus spp . and β‐haemolytic S treptococcus spp . showed a decrease in percent of isolates susceptible to gentamicin over time. E nterobacteriaceae, A ctinobacillus spp . and β‐haemolytic S treptococcus spp. showed an increase in MIC values for amikacin. E nterobacteriaceae showed a decrease in percent of isolates susceptible to ceftiofur. E nterococcus spp . and P seudomonas spp. showed increased MIC values to ceftiofur. E nterobacteriaceae showed increased MIC values to ceftizoxime. E nterococcus spp . became more resistant to imipenem and showed increased MIC values to ticarcillin/clavulanic acid. In contrast, several trends in increased susceptibility were also seen. Conclusions Based on these in vitro 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 in vitro activity of ceftiofur against E nterobacteriaceae is of concern. Similarly, the development of resistance of E nterococcus spp. to imipenem is an important finding that warrants monitoring in the future. Judicious use of antimicrobials is therefore crucial.