Sequence type 398 meticillin‐resistant Staphylococcus aureus infection and colonisation in dogs

Abstract

A ReSPIRATORY disease outbreak was identified in a litter of American boxer dogs at a breeding kennel in Ontario, Canada. Three of the puppies died aged three weeks. Virus isolation was negative but Bordetella bronchiseptica and meticillin-resistant Staphylococcus aureus (MRSA) were isolated from nasal and oropharyngeal samples. The MRSA isolate was spa-type t034, negative for Panton-Valentine leukocidin genes, non-typable by SmaI pulsed-field gel electrophoresis, and sequence type (ST) 398. This clone of MRSA is usually associated with livestock. Typing of the staphylococcal chromosomal cassette determined it to be SCCmecV(nt). The role of MRSA in the death of the puppies was unclear. Because ST398 MRSA has been rarely reported in dogs, and because of the increasing evidence of the importance of ST398 as a zoonotic pathogen, an investigation was undertaken.The kennel consisted of 12 breeding animals (10 females and two males), four adult pet dogs and two pet cats. At the time of initial investigation, two litters of puppies were present, including the litter containing the puppies that died. Two other bitches were pregnant and due to deliver within the next two weeks. Because of the potential for direct transmission of MRSA between certain animals as well as direct transmission from human beings to animals or indirect transmission to animals, all animals were considered potentially exposed and were tested. Nasal and rectal swabs were collected from all animals (12 breeding dogs, four pet dogs, two pet cats and 12 puppies) 21 days after the deaths of the puppies. MRSA was isolated from 12 of 30 (40 per cent) animals ( Table 1): two of 12 (17 per cent) breeding animals (both periparturient bitches), three of four (75 per cent) surviving six-week old puppies from the affected litter, six of eight (75 per cent) three-week old puppies from the other litter, and a pet dog housed in the same pen as the first bitch. The other three dogs and two pet cats were negative for MRSA. household infection control practices were in place, particularly hand hygiene. Contact between colonised (MRSA-positive) dogs and other dogs and people was restricted. It was reported that one of the two people in the household worked on a pig farm. Because of the strong association between ST398 colonisation of human beings and contact with livestock, and the high rates of ST398 colonisation among pig farmers (Van Loo and others 2007), colonised people were considered a possible source of infection for the dogs.Testing was repeated 14 days later. Nasal and rectal samples were collected from 28 originally tested dogs (cats were not retested) and one new dog. Further, two bitches had whelped, and puppies from the two new litters (one of eight puppies and one of five) were also tested, giving a total of 42 dogs tested. In the interim, one of the colonised bitches had developed MRSA gangrenous mastitis and two of its puppies had developed severe MRSA pyoderma. MRSA was isolated from 12 of the 42 (29 per cent) dogs: eight of 25 (32 per cent) puppies ...

Molecular Analysis of Human and Canine Staphylococcus aureus Strains Reveals Distinct Extended-Host-Spectrum Genotypes Independent of Their Methicillin Resistance

“…The isolation of CC398 S. aureus from dogs was reported before (24,25,37), which confirms the ability of these strains to adapt to hosts other than livestock or humans. Overall, comparative analysis of canine and human isolates belonging to CC5, CC22, CC15, CC30, and CC45 revealed a remarkable PFGE pattern concordance, although the canine isolates originated from nine German federal states as well as eight further European countries and were collected over a period of 10 years.…”

A prospective study to examine the epidemiology of methicillin-resistant Staphylococcus aureus and Clostridium difficile contamination in the general environment of three community hospitals in southern Ontario, Canada

“…This spa type is an important cause of community-associated MRSA infection in some regions, particularly northern Europe, most often in individuals with contact with pigs [46-48]. Although this MRSA strain is endemic in the swine population in Canada [49,50] and has also been found in a horse [51] and dogs [52], its role in human infections is unclear. A limited number of human infections have been reported [53], and it remains to be determined whether this is a rare endemic infection, an under diagnosed problem, or an emerging disease in Canada.…”

Transmission Dynamics of Methicillin-Resistant Staphylococcus aureus in Pigs

“…Generally, MRSA strains isolated from these animals have a human genetic background. However, LA-MRSA CC398 has occasionally been detected in cats and dogs due to transmission from humans (mainly veterinary personnel) (Witte et al, 2007; Nienhoff et al, 2009; Floras et al, 2010; Haenni et al, 2012). Until now, the prevalence of MRSA CC398 in companion animals residing on farms is unknown.…”

“…Since their discovery, livestock, and pigs particularly appeared to be an important reservoir for MRSA CC398 colonization and infection of humans in relation to farming worldwide (Huijsdens et al, 2006; Wulf et al, 2006, 2008a; van Loo et al, 2007; Witte et al, 2007; Khanna et al, 2008; Lewis et al, 2008; Nemati et al, 2008; Denis et al, 2009; Krziwanek et al, 2009; Persoons et al, 2009; Smith et al, 2009; Van den Eede et al, 2009; Mammina et al, 2010; Mulders et al, 2010; Graveland et al, 2011; Vandendriessche et al, 2011a; Crombé et al, 2012a). Moreover, a number of clinical cases caused by MRSA CC398 have been described in animals including pigs (Sergio et al, 2007; van Duijkeren et al, 2007; Schwarz et al, 2008; Meemken et al, 2010; van der Wolf et al, 2012), cows (Feßler et al, 2010; Vanderhaeghen et al, 2010; Holmes and Zadoks, 2011; Spohr et al, 2011), horses (Cuny et al, 2008, 2010; Hermans et al, 2008; Sieber et al, 2011), and dogs (Witte et al, 2007; Floras et al, 2010; Haenni et al, 2012). However, MRSA CC398 is not the only lineage recovered from pigs and other animals.…”