No abstract

Two major clonal MRSP lineages have disseminated in Europe (ST71-J-t02-II-III) and North America (ST68-C-t06-V). Regardless of their geographical or clonal origin, the isolates displayed resistance to the major classes of antibiotics used in veterinary medicine and thus infections caused by MRSP isolates represent a serious therapeutic challenge.

Pet animal numbers have substantially increased in modern society and attention is increasingly devoted to pet welfare. Because of these changes, antimicrobial agents are frequently used in small animal veterinary practice, often including antimicrobial preparations used in human medicine, with heavy use of broad-spectrum agents such as aminopenicillins plus clavulanic acid, cephalosporins and fluoroquinolones. Several longitudinal studies conducted at veterinary hospitals have indicated that resistance to various antimicrobial agents has emerged amongst pet animal isolates of Staphylococcus intermedius, Escherichia coli and other bacteria, including species with a potential for zoonotic transmission and resistance phenotypes of clinical interest, such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci and multidrug-resistant Salmonella Typhimurium DT104. Based on a review of the current literature, the role of pets in the dissemination of antimicrobial resistance has been given little attention when compared with that of food animals. A marked contrast is evident between the current policies on antimicrobial usage in food and companion animals. Apart from a few countries where limited data on antimicrobial usage and occurrence of resistance in bacteria from pet animals are provided, national surveillance programmes only focus on food animals. However, data on pet animals are clearly needed for guiding antimicrobial use policy in small animal veterinary practice as well as for assessing the risk of transmission of antimicrobial resistance to humans.

Urinary tract disease is a common reason for use (and likely misuse, improper use, and overuse) of antimicrobials in dogs and cats. There is a lack of comprehensive treatment guidelines such as those that are available for human medicine. Accordingly, guidelines for diagnosis and management of urinary tract infections were created by a Working Group of the International Society for Companion Animal Infectious Diseases. While objective data are currently limited, these guidelines provide information to assist in the diagnosis and management of upper and lower urinary tract infections in dogs and cats.

The dog is the natural host of Staphylococcus pseudintermedius. Many research efforts are currently being undertaken to expand our knowledge and understanding of this important canine commensal and opportunistic pathogen. The objective of this review is to summarize the current knowledge of the species, including the latest research outcomes, with emphasis on taxonomy, diagnostics, ecology, epidemiology and pathogenicity. Despite the important taxonomic changes that have occurred over the past few years, the risk of misidentification in canine specimens is low and does not have serious consequences for clinical practice. Staphylococcus pseudintermedius carriage in the dog is more frequent and genetically heterogeneous compared with that of Staphylococcus aureus in man. It appears that these staphylococcal species have evolved separately through adaptation to their respective natural hosts and differ with regard to various aspects concerning ecology, population structure and evolution of antibiotic resistance. Further understanding of the ecology and epidemiology of S. pseudintermedius is hampered by the lack of a standard method for rapid and discriminatory typing and by the limited data available on longitudinal carriage and population structure of meticillin-susceptible strains. With regard to pathogenicity, it is only now that we are starting to explore the virulence potential of S. pseudintermedius based on genomic and proteomic approaches, and more research is needed to assess the importance of individual virulence factors and the possible existence of hypervirulent strains.