Coagulase-positive staphylococci (CPS) are common cutaneous pathogens often requiring multiple courses of antibiotics, which may facilitate selection for methicillin-resistant (MR) and/or multidrug-resistant (MDR) strains. To determine the prevalence of canine and feline MR/MDR CPS associated with skin diseases, medical records were retrospectively searched from April 2010 to April 2020. Pets with at least one positive culture for CPS were selected. Age, sex, antimicrobial sensitivity, previous history of antimicrobial/immunomodulatory medications and methicillin resistance/multidrug resistance status were recorded. Staphylococcus pseudintermedius (SP) (575/748) and Staphylococcus schleiferi (SS) (159/748) in dogs, and Staphylococcus aureus (12/22) in cats, were the most common CPS isolated. Three hundred and twenty-three out of 575 isolates were MR-SP (56.2 %), 304/575 were MDR-SP (52.8 %), 100/159 were MR-SS (62.9 %) and 71/159 were MDR-SS (44.6 %). A trend analysis showed a significant increase of resistance to oxacillin and chloramphenicol for S. pseudintermedius (r=0.86, 0.8; P=0.0007, 0.0034, respectively). Major risk factors for MDR-SP included oxacillin resistance (OR: 3; 95 % CI: 1.4–6.5; P=0.0044), positivity for PBP2a (OR: 2.3; 95 % CI: 1–5; P=0.031) and use of antibiotics in the previous year (OR: 2.8; 95 % CI: 1.3–5.8; P=0.0071). Oxacillin resistance was identified as a major risk factor for MDR-SS (OR: 8.8; 95 % CI: 3.6–21.1; P<0.0001). These results confirmed the widespread presence of MR/MDR CPS in referred dermatological patients. Judicious antibiotic use, surveillance for MR/MDR infections and consideration of alternative therapies are crucial in mitigating the development of resistant strains.

Leaves of cold-acclimated lemon [Citrus limon (L.) Burm. f.], grapefruit (C. paradisi Macf.), orange [C. sinensis (L.) Osbeck], and mandarin (C. unshiu Marc.) trees ranged in cold hardiness from −4 to −11°C. No significant differences in water content (g H2O/g dry weight) or melting point depression were observed. Plots of liquid water content during freezing (g H2O/g dry weight) vs. temperature were similar for the 4 citrus species. The tissues apparently deviated from ideal freezing behavior because less ice was formed. The reduced ice formation could not be accounted for by osmotic effects. Negative pressure potential developed during freezing is hypothesized to play a role in tissue water potential in frozen systems. It was concluded that hardier Citrus leaves survive freezing of a larger fraction of their tissue water.