Sun J, Fu G, Lin J, Song X, Lu L, Liu Q

Sun J, Fu G, Lin J, Song X, Lu L, Liu Q. horizontal direct\contact transmission between dogs. SA2 San Antonio 2 strainsubspecies genotype Isubspecies spp 1.?INTRODUCTION The genus consists of over 40 globally distributed species of alpha\proteobacteria, infecting a wide range of mammalian hosts including dogs.1, 2 Studies on exposure in dogs have described an epidemiologic association between spotted fever group spp. (SFGR) and species.3, 4, 5, 6, 7 Based on contamination of both fleas and ticks with spp. and SFGR, it is assumed that this serologic association between these 2 pathogens represents exposure from coinfected vectors or sequential exposure to multiple infected vectors. As the dynamics of spp. and SFGR seroreactivity in coexposed dogs have not previously been explored in a controlled setting, it is also possible that contamination with (contamination. Vector transmission of different species by sand flies, fleas, lice, ticks, and flies is reasonably well documented by laboratory and field studies8, 9, 10and transmission by a variety of other vectors has been suspectedbut defining a single natural vector for transmission among dogs has proved difficult.1, 9, 10, 11 Nonvectorial routes of transmission of spp. are also proposed. Being scratched by an infected, flea\infested catallowing inoculation of flea feces under the skinis a well\known route of transmission for (spp. by needle stick and blood transfusion has been reported, demonstrating direct transmission via infected cells, blood, or interstitial fluid in the absence of passage through an arthropod vector.12, 13, 14, 15, 16 There are also reports implicating transmission by bites or suggesting the possibility of viable spp. bacteria in the mouth or saliva.17, 18, 19 In Korea, DNA was PCR\amplified from over 15% of pet canine saliva samples and almost 30% of toenail samples,20 and in the United States LY2886721 5 of 44 Golden Retrievers sampled had spp. DNA on oral swabs.21 DNA was found in the saliva of a man with angioedema of the tongue and in his healthy doggie,22 and in eastern China exposure was associated with doggie bites.23 However, the extent to which saliva might LY2886721 be infectious has not been established and direct transmission among dogs has not been reported. Despite the evidence of nonvectorial routes of transmission, in the absence of concurrent flea infestation, the risk of transmission is currently considered minimal.24, 25 However, if transmission can occur directly between dogsor from dogs to humans in the absence of vectorsthis could be of substantial importance. Establishment of an experimental model of spp. contamination in non\reservoir hosts has thus far remained elusive,26 so investigation of the potential for direct transmission of spp. has been confined to epidemiologic associations and case reports. The original study objective was to evaluate sequentially timed serological response to low\dose experimental contamination in laboratory\raised dogs. However, after completion of the study, DNA was detected in ear\tip vasculitis lesions in 1 doggie. Subsequently, spp. antibodies were documented in all dogs, either before or after the experimental contamination in a vector\free biocontainment facility. This unexpected circumstance provided an opportunity to investigate both the serologic response to coinfection with these 2 previously associated pathogens, as well as to investigate the potential for reactivation and non\vectorial transmission of species. Therefore, the objective of this study was to describe an outbreak investigation of occult spp. contamination among a group of laboratory\reared dogs subsequent to experimentally induced contamination. 2.?METHODS 2.1. Animals The animals included in this study were 6 healthy purpose\bred laboratory\reared female Beagles age 6\12?months (to protect their identities, referred to here as and testing were negative. The vendor’s canine housing facility consists of indoor/outdoor concrete\floor runs. The vendor practices routine pest control for LY2886721 the facility environment, but study Mouse monoclonal to IKBKE dogs were not treated with flea/tick preventatives while housed at the vendor. The study was approved by the NCSU Institutional Animal Care and Use Committee (Protocol #16\206). 2.2. Study timeline The dogs were acquired from a commercial vendor and arrived at the NCSU LAR facility on December 19, 2016. The study timeline is divided into 3 phases: pre\inoculation (monitoring (monitoring During the EF phase, dogs were moved to various locations within LAR (Physique ?(Figure1B).1B). Four dogs were housed as pairs (and together, and and together), and 2 dogs (and contamination in dogseach doggie was inoculated with 3??105 TCID50 (Median Tissue Culture Infectious Dose) of LY2886721 via intradermal injection on March 20, 2017. Inoculum was prepared from frozen stocks of a canine isolate derived from a clinical case of Rocky Mountain spotted fever (RMSF; NCSU\2008\CO4, Murphy strain).27 The LY2886721 inoculum was prepared in the NCSU College of Veterinary Medicine Biosafety Level.