Human Colonization and Infection by Staphylococcus pseudintermedius: An Emerging and Underestimated Zoonotic Pathogen

Abstract

S. pseudintermedius is a known resident of the skin and mucous membranes and a constituent of the normal microbiota of dogs. It has also been recognized as an opportunistic and zoonotic pathogen that is able to colonize humans and cause severe diseases, especially in immunocompromised hosts. Most importantly, methicillin-resistant S. pseudintermedius (MRSP), which is intrinsically multidrug-resistant, has emerged with serious public health consequences. The epidemiological situation is further exacerbated with reports of its zoonotic transmission and human infections which have been mostly attributed to the increasing frequency of dog ownership and close contact between dogs and humans. Evidence on the zoonotic transmission of MRSP from pet dogs to humans (such as dog owners, small-animal veterinarians, and other people in close proximity to dogs) is limited, especially due to the misidentification of S. pseudintermedius as S. aureus. Despite this fact, reports on the increasing emergence and spread of MRSP in humans have been increasing steadily over the years since its first documented report in 2006 in Belgium. The emergence of MRSP strains has further compromised treatment outcomes in both veterinary and human medicine as these strains are resistant to beta-lactam antimicrobials usually prescribed as first line treatment. Frustratingly, the limited awareness and surveillance of the zoonotic transmission of S. pseudintermedius have underestimated their extent of transmission, prevalence, epidemiology, and public health significance. In order to fill this gap of information, this review focused on detailed reports on zoonotic transmission, human colonization, and infections by S. pseudintermedius, their pathogenic features, antimicrobial resistance profiles, epidemiology, risk factors, and treatment. In writing this review, we searched Web of Science, PubMed, and SCOPUS databases using the keyword “Staphylococcus pseudintermedius AND humans”. A phylogenetic tree to determine the genetic relatedness/diversity of publicly available genomes of S. pseudintermedius was also constructed.

Antimicrobial Resistant Staphylococcus Species Colonization in Dogs, Their Owners, and Veterinary Staff of the Veterinary Teaching Hospital of Naples, Italy

“…This high S. pseudintermedius occurrence is not surprising, as other published studies described S. pseudintermedius as a normal constituent of the microbial flora in the nasal cavities of dogs [ 45 ], but also as the main opportunistic canine pathogen associated with canine skin disorders, such as otitis externa and pyoderma [ 21 , 46 , 47 , 48 , 49 ]. Moreover, this opportunistic microorganism has been reported as responsible for diseases in humans, associated with contact with dogs, suggesting zoonotic transmission [ 16 , 50 , 51 ]. Transmission can be hypothesized for the dog–owner interaction in our study, where both the dog suffering from pyoderma and its owner were positive for S. pseudintermedius strains, showing a comparable antimicrobial resistance profile.…”

Antimicrobial resistance and virulence profiling of Staphylococcus pseudintermedius isolated from cats, Bangladesh

“…The isolation of S. pseudintermedius appears to be more prevalent in the perineum compared to the anterior nares or oropharynx (Moses et al. 2023 ). These body sites have been identified as the most often colonized sites for S. pseudintermedius in dogs that have also been true for cats as reported in various investigations (Garbacz et al.…”

“…MRSP has been reported as a significant pathogen in the field of veterinary medicine particularly for pet animals like MRSA in humans and food animals (Moses et al. 2023 , Rana et al. 2022b , Rana et al.…”

Epidemiologic case investigation on the zoonotic transmission of Methicillin-resistant Staphylococcus pseudintermedius among dogs and their owners

“…It cannot be definitively stated which factors predispose the transmission of S. pseudintermedius between animals-owners and vice-versa. However, some points, such as close contact and owners who frequent or are involved in hospital environments, stand out among these points could favor this zoonotic transmission, especially of MRSPs [45] . These were also noted in this study.…”