In‐vitro susceptibility to antimicrobial drugs of bacterial isolates from horses in The Netherlands

Abstract

Summary Minimum inhibitory concentrations (MICs) of 30 antimicrobial agents (including the hitherto unreported antimicrobial agents doxycycline, minocycline, vanomycin, 3 quinolones and 3 combinations of antimicrobial agents) for isolates of Salmonella spp. (20), Escherichia coli (17), Klebsiella spp. (8), Proteus spp. (7), Pseudomonas aeruginosa (7), Actinobacillus equuli (5), Rhodococcus equi (4), Streptococcus zooepidemicus (23), Streptococcus equisimilis (6), Streptococcus equi (4), coagulase‐positive Staphylococcus spp. (20) and Taylorella equigenitalis (19) were determined using the agar dilution method. All isolates were of equine origin. MICs were compared with recommended MIC breakpoints. The results indicate that, for some of the pathogenic bacteria evaluated, susceptibility testing of isolates from the individual patient is essential to determine an appropriate antimicrobial treatment.

In Vitro Susceptibilities of Rhodococcus equi and Other Common Equine Pathogens to Azithromycin, Clarithromycin, and 20 Other Antimicrobials

“…CLR and AZM were not active in vitro against other equine gram-negative bacterial pathogens ( Table 2). MICs of other antimicrobials against equine gram-negative pathogens were similar to values previously reported (8), with the notable exception that in the present study, a larger proportion of E. coli isolates were resistant to enrofloxacin. We thank the personnel of the microbiology laboratory of the University of Florida Veterinary Medical Teaching Hospital for technical assistance.…”

“…Many studies have determined in vitro susceptibilities of equine pathogens using the disk diffusion method, but few studies have reported MICs (1,5,8). To our knowledge, there are no studies evaluating in vitro susceptibilities of AZM and CLR against common equine bacterial pathogens.…”

MICs of Oxazolidinones for Rhodococcus equi Strains Isolated from Humans and Animals

“…The oxazolidinones are most active against gram-positive organisms including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp., and Streptococcus spp. The in vitro activity of these compounds against a variety of bacterial isolates from humans as well as animals has been well documented (5)(6)(7)(8)13 R. equi strains used in this study were from the Pharmacia & Upjohn Animal Health Discovery Research culture collection (Kalamazoo, Mich.). All strains used in this study were identified as the primary cause of infection in the patients.…”

“…Erythromycin and rifampin (initially) therapy for 4 to 9 weeks has become the treatment of choice for foals (5,6). However, due to cost, clinicians and owners of affected animals are interested in a less costly therapy, and if possible monotherapy, to treat foals.…”

Antimicrobial Susceptibility of 616 Rhodococcus equi Strains Isolated from Tracheobronchial Aspirates of Foals Suffering from Respiratory Disease in Japan

“…In addition, incidences of rifampin-resistant R. equi have been reported recently [2,7,17]. Several published papers have reported on the susceptibility to antimicrobials of R. equi isolated from horses and humans in Canada, France, Netherlands, the UK and USA [1,5,6,9,11,12,18]. However, the number of isolates or t ypes of antimicrobial agents in these papers was limited.…”