Multi-drug and methicillin resistance of staphylococci from canine patients at a veterinary teaching hospital (2006–2011)

Figures & data

Figure 1. Percentage prevalence of all methicillin-resistant staphylococci isolates compared at all sites from 2006 to 2011.

Figure 2. Percentage prevalence of methicillin resistance of all staphylococci and S. pseudintermedius cultured from all sites, ears, and skin between 2006 and 2011. Key: Staphylococci (Staph), S. pseudintermedius (Stapse).

Figure 3. Comparison of all multi-drug-resistant (MDR) staphylococci isolates cultured from the skin between 2006 and 2011. Key: # = isolates resistant to # antimicrobial classes (ex. 3 = resistant to 3 antimicrobial classes).

Figure 4. Comparison of the multi-drug-resistant (MDR) S. pseudintermedius isolates cultured from the skin between 2006 and 2011. Key: # = isolates resistant to # antimicrobial classes (ex. 3 = resistant to 3 antimicrobial classes); * = statistically significant mean cumulative resistance score comparing 2006 and 2010. Statistical significance: p < 0.05.

Figure 5. Mean resistance score of S. pseudintermedius at all sites over the 6-year period. *, † = statistically significant mean resistance score comparing 2006 and 2008, and 2006 and 2009, respectively. Statistical significance: p < 0.05.

Figure 6. Mean resistance score of all staphylococci at all sites over the 6-year period. * = statistically significant mean resistance score comparing 2006 and 2008. Statistical significance: p < 0.05.

Table 1. Number of canine isolates resistant to tested antimicrobials between 2006 and 2011.

		Year
Isolates	Resistant antibiotic	2006	2007	2008	2009	2010	2011	Total
Stapse		(n = 126)	(n = 140)	(n = 160)	(n = 128)	(n = 130)	(n = 132)	(n = 816)
	β-Lactams*	97	118	127	106	107	106	661
	Meth-/Oxacillin^†§ (p = 0.029)	6	5	4	5	14	6	40
	Chloramphenicol	3	4	8	5	7	9	36
	Clindamycin^§ (p = 0.004)	11	26	43	32	32	29	173
	Doxycycline^§ (p < 0.0001)	–	–	–	6	25	33	64
	Enrofloxacin	4	12	20	14	12	9	71
	Erythromycin^§ (p < 0.0001)	8	33	51	38	36	38	204
	Gentamicin^§ (p < 0.0001)	10	5	26	27	26	16	109
	Marbofloxacin* (p = 0.034)	3	11	21	14	13	9	71
	Rifampin	0	0	3	2	5	3	13
	Tetracycline^§ (p < 0.0001)	43	47	62	38	3	5	198
	Trimethoprim-sulfonamide	18	24	33	25	19	24	143
SA		(n = 28)	(n = 36)	(n = 30)	(n = 25)	(n = 29)	(n = 18)	(n = 166)
	β-Lactams*	25	30	28	19	28	14	144
	Oxacillin^†§ (p = 0.026)	14	7	7	10	11	2	51
	Chloramphenicol	4	0	4	4	8	2	22
	Clindamycin	7	6	5	4	9	2	33
	Doxycycline	–	–	–	0	1	0	1
	Enrofloxacin	5	1	7	6	9	2	30
	Erythromycin^§ (p = 0.032)	11	17	9	11	21	7	76
	Gentamicin	1	3	3	3	0	0	10
	Marbofloxacin§ (p = 0.049)	2	2	6	6	9	2	27
	Rifampin	0	0	2	0	1	0	3
	Tetracycline^§ (p = 0.043)	1	3	6	3	0	0	13
	Trimethoprim-sulfonamide	0	2	3	1	1	0	7
Stacoa		(n = 6)	(n = 10)	(n = 14)	(n = 10)	(n = 15)	(n = 6)	(n = 61)
	β-Lactams*	4	4	7	4	5	1	25
	Oxacillin^†	2	2	1	1	4	1	11
	Chloramphenicol	0	0	0	0	0	0	0
	Clindamycin	0	0	1	1	0	0	2
	Doxycycline	–	–	–	0	0	0	0
	Enrofloxacin	0	3	1	2	2	1	9
	Erythromycin	0	0	2	1	1	0	4
	Gentamicin	3	2	6	4	3	0	18
	Marbofloxacin^§ (p < 0.0001)	0	5	1	2	2	1	11
	Rifampin	0	0	1	0	1	1	3
	Tetracycline	1	0	1	1	0	0	3
	Trimethoprim-sulfonamide	0	0	0	1	0	0	1

Note: Number of S. pseudintermedius (Stapse), S. aureus (SA), and S. schleiferi v. coagulans (Stacoa) isolates resistant to selected antimicrobials by year derived from canine clinical samples between 2006 and 2011.

*β-Lactam (penicillins, cephalosporins, and carbapenems) resistance most commonly referred to ampicillin and penicillin.

^†Oxacillin-resistant isolates were also reported as resistant to all β-lactam drugs (penicillins, cephalosporins, and carbapenems).

^§Statistical significance: p < 0.05. All intermediate susceptibilities were considered resistant.

“–” Denotes isolates not tested.