Table 5.
Distribution of antimicrobial and multidrug resistance among S. schleiferi isolated from canine specimens submitted to a veterinary diagnostic laboratory in Tennessee, USA (2006–2017)
| Antimicrobial | 2006–2008 | 2009–2011 | 2012–2014 | 2015–2017 | Total |
|---|---|---|---|---|---|
| Aminoglycosides | |||||
| Gentamicin | 41.03 (16/39) | 48.3 (14/29) | 50.0 (11/22) | 45.5 (10/22) | 45.5 (51/112) |
| β-lactams | |||||
| Ampicillin | 60.5 (23/38) | 55.2 (16/29) | 45.0 (18/40) | 63.0 (34/54) | 56.5 (91/161) |
| Cefoxitin | 20.5 (8/39) | 17.2 (5/29) | 32.5 (13/40) | 30.2 (16/53) | 26.1 (42/161) |
| Oxacillin | 66.7 (26/39) | 65.5 (19/29) | 52.5 (21/40) | 57.4 (31/54) | 59.9 (97/162) |
| Fluoroquinolones | |||||
| Marbofloxacin | 39.5 (15/38) | 51.7 (15/29) | 51.3 (20/39) | 50 (23/46) | 48.0 (73/152) |
| Folate inhibitors | |||||
| TMSa | 0 (0/39) | 3.5 (1/29) | 2.5 (1/40) | 3.7 (2/54) | 2.5 (4/162) |
| Lincosamides | |||||
| Clindamycin | 10.3 (4/39) | 6.9 (2/29) | 0 (0/40) | 14.8 (8/54) | 8.6 (14/162) |
| Macrolides | |||||
| Erythromycin | 10.3 (4/39) | 6.9 (2/29) | 0 (0/40) | 14.8 (8/54) | 8.6 (14/162) |
| Phenicols | |||||
| Chloramphenicol | 0 (0/39) | 3.5 (1/29) | 0 (0/40) | 0 (0/54) | 0.6 (1/162) |
| Tetracyclines | |||||
| Tetracycline | 0 (0/39) | 6.9 (2/29) | 5 (2/40) | 13.0 (7/54) | 6.8 (11/162)* |
| AMRb | 84.6 (33/39) | 82.8 (24/29) | 72.5 (29/40) | 72.2 (39/54) | 77.2 (125/162) |
| MDRc | 28.2 (11/39) | 34.5 (10/29) | 20.0 (8/40) | 27.8 (15/54) | 27.2 (44/162) |
| MRSSd | 61.8 (21/34) | 64.3 (18/28) | 48.7 (19/39) | 55.8 (29/52) | 56.9 (87/153) |
aTrimethoprim/sulfamethoxazole
bAntimicrobial resistance
cMultidrug resistance
dMethicillin-resistant S. schleiferi, based on oxacillin disk diffusion testing confirmed with positive mecA PCR
*p < 0.05, **p < 0.01, ***p < 0.0001 for Cochran-Armitage trend test