Dog visits in nursing homes - increase complexity or keep it simple? A randomised controlled study

Establishment of a Multilocus Sequence Typing Scheme for Pasteurella canis Using Isolates from Infected Humans and Diseased Companion Animals

Background

Multilocus sequence typing (MLST) is well-established for Pasteurella multocida but remains undeveloped for Pasteurella canis. We established MLST for P. canis using isolates from humans and companion animals in Japan and Korea to gain insights into its population biology.

Methods

We analyzed 39 and 22 isolates from companion animals and humans, respectively. We selected seven housekeeping genes-adk, aroA, deoD, gdhA, g6pd, mdh, and pgi-used in P. multocida MLST. Primer pairs for PCR amplification and sequencing were designed based on conserved sites in 10 whole-genome sequences. We determined fragment sequences, variable sites, allelic profiles, and sequence types (STs) of each isolate. A phylogenetic tree of concatenated sequences was constructed using the goeBURST algorithm to identify STs and clonal complexes (CCs). ompA, encoding outer membrane protein A, was genotyped for molecular characterization.

Results

The sequenced fragment lengths and allele numbers of the seven genes were 424, 451, 483, 439, 429, 419, and 440 bp and 16, 13, 15, 18, 22, 19, and 18, respectively. ST1-ST47, including CC2, CC10, CC18, CC31, and CC33, were diversely distributed among the isolates from different hosts/countries. In the seven-gene phylogenetic tree, apart from P. multocida, all isolates clustered together. goeBURST diagrams revealed diverse ST distributions among different hosts (animal/human) and countries (Japan/Korea/ others). We found clusters 1-4 in ompA genotyping, indicating that MLST discrimination is higher than ompA typing discrimination.

Conclusions

We established MLST for P. canis isolates from humans and companion animals in Japan and Korea, thereby providing a robust tool for population biology studies.

How to Measure Human-Dog Interaction in Dog Assisted Interventions? A Scoping Review

Human-dog interaction is the working tool through which the therapeutic, educational and recreational goals of dog-assisted interventions (DAIs) are achieved. A better understanding of the characteristics of this interaction could improve the effectiveness of DAIs. This scoping review addresses the question: how has the human-dog connection been measured in the context of DAIs? After searching the Web of Science and Scopus platforms, only peer-reviewed, primary research studies reporting measures of therapy dog-human interaction, relationship and bond were included. A total of 70 included articles provided information on what was measured (interaction, relationship or bond) and how, as well as the general context (DAIs or experimental situations with therapy dogs). While the majority of the articles identified use behavioural analysis methods to analyse the interaction between the participant/recipient and the therapy dog during DAIs, it was possible to identify some more structured tools that assess the participant/recipient's interaction, relationship or bond with the therapy dog, as well as tools that consider the animal's perspective or focus on the dog-handler dyad, indicating growing areas of research. The tools and methods identified can be used by both practitioners and researchers to further explore aspects of human-dog interaction in the field of DAIs.

Comparative Genomic Analysis of Staphylococcal Cassette Chromosome mec Type V Staphylococcus aureus Strains and Estimation of the Emergence of SCCmec V Clinical Isolates in Korea

Background

Staphylococcal cassette chromosome mec type V (SCCmec V) methicillin-resistant Staphylococcus aureus (MRSA) has been recovered from patients and livestock. Using comparative genomic analyses, we evaluated the phylogenetic emergence of SCCmec V after transmission from overseas donor strains to Korean recipient strains.

Methods

Sixty-three complete MRSA SCCmec V genomes (including six Korean clinical isolates) were used to construct a phylogenetic tree. Single-nucleotide polymorphisms were identified using Snippy, and a maximum-likelihood-based phylogenetic tree was constructed using RAxML. The possible emergence of the most common ancestor was estimated using BactDating. To estimate mecA horizontal gene transfer (HGT) events, Ranger-dtl was applied to 818 SCCmec V strains using publicly available whole-genome data.

Results

The phylogenetic tree showed five major clades. German strains formed a major clade; their possible origin was traced to the 1980s. The emergence of Korean SCCmec V clinical isolates was traced to 2000-2010. mecA HGT events in Staphylococcus spp. were identified in seven strains. P7 (Hong Kong outbreak strain) served as the donor strain for two Korean sequence type (ST) 59 strains, whereas the other five recipient strains emerged from different SCCmec V donors.

Conclusions

Most Korean SCCmec V strains may have emerged during 2000-2010. A unique MRSA SCCmec V strain, ST72 (a Korean common type of community-associated MRSA), was also identified. The genomic dynamics of this clone with a zoonotic background should be monitored to accurately understand MRSA evolution.

Biotypic and genotypic diversity in Pasteurella canis isolated from host animals and humans: differences in trehalose fermentation and nucleotide sequences encoding trehalose-6-phosphate hydrolase (treC)

The biotypic and genotypic features of Pasteurella canis isolated from dogs, cats, and humans were clarified by repetitive sequence-based fingerprinting and nucleotide sequences encoding trehalose-6-phosphate hydrolase (treC). Thirty P. canis and 48 P. multocida isolates were collected from dogs, cats, and humans to perform biotyping. The genotyping of P. canis by fingerprinting was followed by dendrogram construction. The whole-genome sequences (WGSs) were searched for the enzyme-coding nucleotide sequences around the main and adjacent loci constituting the operon. Full-length nucleotide sequences encoding the enzyme were determined using polymerase chain reaction and direct sequencing. Biotypic results were compared to the dendrogram and nucleotide sequence data. We observed a difference in trehalose fermentation with a positivity rate of 46.7%. Two (A-1/A-2) and three (B-1/B-2/B-3) clades were located on the dendrograms generated based on two repetitive sequence-based fingerprinting techniques, showing no association between trehalose fermentation and the clades. Based on the WGSs, two variants of the gene, namely, a 1,641 bp gene treC and a pseudogene (1,335 bp) of treC with its first 306 nucleotides deleted, were observed. Trehalose-positive isolates harbored treC, whereas trehalose-negative isolates lacked treC with or without the pseudogene. Our observations suggest biotypic and genotypic diversity among the P. canis isolates from animal and human hosts, with respect to trehalose fermentation and treC nucleotide sequences. This is the first report on the diversity of treC nucleotide sequences among these isolates.