Staphylococcus pseudintermedius is an important canine pathogen implicated in an increasing number of human infections. Along with rising levels of methicillin and multidrug resistance, staphylococcal biofilms are a complicating factor for treatment and contribute to device, implant, and surgical infections. Staphylococcal virulence, including biofilm formation, is regulated in part by the quorum sensing accessory gene regulator system (agr). The signal molecule for agr, known as the autoinducing peptide molecule, contains polymorphisms that result in the formation of distinct groups. In S. pseudintermedius, 4 groups (i.e., groups I, II, III, and IV) have been identified but not comprehensively examined for associations with infection type, virulence factor carriage, or phylogenetic relationships—all of which have been found to be significant in S. aureus. In this study, 160 clinical canine isolates from Texas, including isolates from healthy dogs (n = 40) and 3 different infection groups (pyoderma, urinary tract, and surgical, n = 40 each), were sequenced. The agr group, biofilm-producing capabilities, toxin gene carriage, antimicrobial resistance, and sequence type (ST) were identified for all isolates. While no significant associations were discovered among the clinical infection types and agr groups, agr II isolates were significantly less common than any other group in diseased dogs. Furthermore, agr II isolates were less likely than other agr groups to be multidrug resistant and to carry toxin genes expA and sec-canine. Fifty-two (33%) of the 160 isolates were methicillin resistant, and the main sequence types (ST64, ST68, ST71, ST84, ST150, and ST155) of methicillin-resistant strains of S. pseudintermedius (MRSP) were identified for the geographic region. IMPORTANCE Staphylococcus pseudintermedius is an important disease-causing bacterium in dogs and is recognized as a growing threat to human health. Due to increasing multidrug resistance, discovery of alternative methods for treatment of these infections is vital. Interference with one target for alternative treatment, the quorum sensing system agr, has demonstrated clinical improvement of infections in S. aureus animal models. In this study, we sequenced and characterized 160 clinical S. pseudintermedius isolates and their agr systems in order to increase understanding of the epidemiology of the agr group and clarify its associations with types of infection and antimicrobial resistance. We found that isolates with agr type II were significantly less common than other agr types in diseased dogs. This provides valuable information to veterinary clinical microbiologists and clinicians, especially as less research has been performed on infection associations of agr and its therapeutic potential in S. pseudintermedius than in S. aureus.

Ranavirus can cause disease in reptiles and amphibians. Because survival time outside of a host remains uncertain, equipment must be disinfected to prevent transmission of ranaviruses. However, disinfectant efficacy against amphibian ranaviruses has not been investigated for chlorhexidine (Nolvasan ® ), sodium hypochlorite (bleach), or potassium compounds. Our goal was to determine the efficacy of Nolvasan ® (0.25, 0.75 and 2.0%), bleach (0.2, 1.0, 3.0 and 5.0%), and Virkon S ® (1.0%) at inactivating Ranavirus at 1 and 5 min contact durations. Potassium permanganate (KMnO 4 ) (2.0 and 5.0 ppm) was also tested with a 60 min contact time. Nolvasan ® at 0.75 and 2.0% and bleach at 3.0 and 5.0% concentration were effective for both contact durations. Virkon S ® was effective for both durations, but KMnO 4 was not effective at either concentration. Concentrations of Nolvasan ® , bleach and Virkon S ® that are at least 0.75, 3.0 and 1.0%, respectively, are effective at inactivating Ranavirus after 1 min exposure time.KEY WORDS: Ranavirus · Amphibians · Disinfection · Chlorhexidine · Pathogen pollution · Potassium peroxymonosulfate · Potassium permanganate · Sodium hypochlorite Resale or republication not permitted without written consent of the publisherDis Aquat Org 84: [89][90][91][92][93][94] 2009 commercial activities , Picco et al. 2007, Storfer et al. 2007).Researchers and tourists may also spread ranaviruses by traveling between contaminated and uncontaminated areas. Overland transport of ranaviruses to new areas could occur via contaminated surfaces, such as hands, nets, shoes or other field equipment (Converse & Green 2005). Fomite transmission has been linked to Ranavirus outbreaks in other aquatic species, including epizootic haematopoietic necrosis virus (EHNV) in redfin perch Perca fluviatilis (Langdon 1989). Langdon (1989) found that viral particles (virions) of EHNV remained infective for over 113 but less than 200 d on dry surfaces, and for at least 97 d in water. Because survival time of anuran ranaviruses remains uncertain outside the host, amphibian biologists, ranaculturalists and zoo personnel thoroughly disinfect equipment to prevent possible spread of Ranavirus to naïve populations (Fish and Wildlife Service 2008).Disinfectants must be safe for use with amphibians and must inactivate a significant proportion of Ranavirus to be deemed effective. Efficacy is determined by quantifying the number of virions present in a sample after one application of the disinfectant, with an effective agent producing at least a 3 log 10 (99.9% inactivated) reduction in titer (Scott 1980, Environmental Protection Agency 2008. Chlorhexidine, sodium hypochlorite (bleach) and potassium compounds are the most common disinfectants used by field biologists and zoological facilities (Hadfield & Whitaker 2005), but none of the 3 has been tested for its efficacy at inactivating Ranavirus. A 1.0% concentration of bleach is used to clean non-porous surfaces and is considered a safe concentration for use with amph...

Identification of fungal organisms often poses a problem for pathologists because the histomorphology of some fungal organisms is not specific, fresh tissues may not be available, and isolation and identification in culture may take a long time. The purpose of this study was to validate the use of panfungal polymerase chain reaction (PCR) to identify fungal organisms from formalin-fixed paraffin-embedded (FFPE) tissues. Formalin-fixed paraffin-embedded curls were tested from 128 blocks containing canine, feline, equine, and bovine tissues with cutaneous, nasal, pulmonary, and systemic fungal infections, identified by the presence of fungi in histologic sections. Quantitative scoring of histologic sections identified rare (11.9%), occasional (17.5%), moderate (17.5%), or abundant (53.1%) fungal organisms. DNA was isolated from FFPE tissues and PCR was performed targeting the internal transcribed spacer 2 (ITS-2) region, a segment of noncoding DNA found in all eukaryotes. Polymerase chain reaction products were sequenced and identified at ≥97% identity match using the Basic Local Alignment Search Tool and the NCBI database of ITS sequences. Of the 128 blocks, 117 (91.4%) yielded PCR products and high-quality sequences were derived from 89 (69.5%). Sequence and histologic identifications matched in 79 blocks (61.7%). This assay was capable of providing genus- and species-level identification when histopathology could not and, thus, is a beneficial complementary tool for diagnosis of fungal diseases.

Extreme intestinal polyposis in pet dogs has not yet been reported in literature. We identified a dog patient who developed numerous intestinal polyps, with the severity resembling human classic familial adenomatous polyposis (FAP), except the jejunum-ileum junction being the most polyp-dense. We investigated this dog, in comparison with 22 other dogs with spontaneous intestinal tumors but no severe polyposis, and with numerous published human cancers. We found, not APC mutation, but three other alteration pathways as likely reasons of this canine extreme polyposis. First, somatic truncation mutation W411X of FBXW7, a component of an E3 ubiquitin ligase, over-activates MYC and cell cycle-promoting network, accelerating crypt cell proliferation. Second, genes of protein trafficking and localization are downregulated, likely associated with germline mutation G406D of STAMBPL1, a K63-deubiquitinase, and MYC network activation. This inhibits epithelial apical-basolateral polarity establishment, preventing crypt cell differentiation. Third, Bacteroides uniformis, a commensal gut anaerobe, thrives and expresses abundantly thioredoxin and nitroreductase. These bacterial products could reduce oxidative stress linked to host germline mutation R51X of CYB5RL, a cytochrome b5 reductase homologue, decreasing cell death. Our work emphasizes the close collaboration of alterations across the genome, transcriptome and microbiome in promoting tumorigenesis.

Five cases of Rhodococcus equi infection in dogs were identified from 2003 to 2014. Three of the dogs had severe, internal lesions attributable to R. equi that have not been previously described: endophthalmitis, endocarditis, and suppurative pleuropneumonia. Isolates from 4 of the dogs were analyzed by polymerase chain reaction for Rhodococcus virulence-associated plasmid (vap) genes. One isolate was vapA-positive, 2 lacked a virulence plasmid, and 1 carried the novel vapN-associated plasmid (pVAPN) recently characterized in bovine isolates. The pVAPN plasmid has not been described in isolates cultured from companion animals. Four of the dogs either were receiving immunosuppressive drugs or had endocrinopathies. R. equi has the potential to cause significant infections in dogs, and immunocompromised animals should be considered at risk for infection.