Serotype and virulence genes of Klebsiella pneumoniae isolated from mink and its pathogenesis in mice and mink.
ABSTRACT: In the study, 15?K. pneumoniae strains were isolated from the mink experiencing respiratory distress in mideastern Shandong province, China, and the prevalence of K. pneumoniae in the sampled mink was 11.9% (15/126). Fourteen (93.33%) of the 15?K. pneumoniae isolates were identified as serotype K2 and hypermucoviscosity phenotype. The 12 virulence-associated genes of the K. pneumoniae isolates were tested. The prevalence of the wabG gene for the isolates were 100% (15/15), the ureA gene 100% (15/15), the rmpA gene 93.33% (14/15), the aerobactin gene 93.33% (14/15), the uge gene 93.33% (14/15), the IucB gene 80% (12/15) and the ybtA gene 13.33% (2/15). But the other five genes, fim, iroNB, wcaG, alls and kfuBC, gave a negative PCR reaction in the 15 isolates, respectively. The animal experiments using K. pneumoniae-SD-12 and K. pneumoniae-SD-21 demonstrated that the serotype K2 was high virulence for mice and mink. These finding implied there exist potential threat that K. pneumoniae pathogens could transmit to human, especially the fur animal farm workers and residents lived near the fur animal farms. Therefore, the etiology and epidemiological surveillance of K. pneumoniae in mink should be strengthened for people's public health.
Project description:H9N2 influenza A virus (IAV) causes low pathogenic respiratory disease and infects a wide range of hosts. In this study, six IAVs were isolated from mink and identified as H9N2 IAV. Sequence analysis revealed that the six isolates continued to evolve, and their PB2 genes shared high nucleotide sequence identity with H7N9 IAV. The six isolates contained an amino acid motif PSRSSR?GL at the hemagglutinin cleavage site, which is a characteristic of low pathogenic influenza viruses. A serosurvey demonstrated that H9N2 IAV had spread widely in mink and was prevalent in foxes and raccoon dogs. Transmission experiments showed that close contact between H9N2-infected mink and naive mink, foxes and raccoon dogs resulted in spread of the virus to the contact animals. Furthermore, H9N2 challenge experiments in foxes and raccoon dogs showed that H9N2 IAV could infect these hosts. Virological and epidemiological surveillance of H9N2 IAV should be strengthened for the fur animal industry.
Project description:The spread of colistin resistance gene mcr-1 at the animal-human interface remains largely unknown. This work aimed to investigate the molecular characteristics of two extended-spectrum-?-lactamase (ESBL)-producing Escherichia coli strains with mcr-1, i.e., strains H8 and H9, isolated from the same mink farmer. In this study, five mcr-positive E. coli strains were isolated from the mink farm. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) identified two genetically unrelated MCR-1 producers (H8 and H9) from the same farmer and two clonally related MCR-1-positive isolates (M5 and M6) from two different mink samples. Additionally, a mcr-1 variant, designated mcr-1.12, was identified in isolate M4. MIC determination revealed that all of the MCR-producing strains exhibited multiresistant phenotypes but showed susceptibility to imipenem, meropenem, amikacin, and tigecycline. Replicon typing showed that mcr-1 was associated with IncHI2 plasmids in 4 cases, while the gene was located on an IncI2 plasmid in 1 case. PacBio sequencing and plasmid analysis confirmed that the mcr-1 gene was located on an ?204-kb IncHI2 plasmid in H8 and was carried by an ?61-kb IncI2 plasmid in H9. To our knowledge, this work represents the first report of the occurrence of MCR-producing isolates from mink. Moreover, our report also describes the coexistence of two different MCR-1 producers in the same farmer. It highlights that fur farms can be reservoirs of mcr-1 genes. The identification of mcr-carrying plasmids on a fur farm is of potential public health importance, as it suggests that mcr is widespread in the animal husbandry industry.IMPORTANCE Colistin resistance is a real threat for both human and animal health. The mobile colistin resistance gene mcr has contributed to the persistence and transmission of colistin resistance at the interfaces of animals, humans, and ecosystems. Although mcr genes have usually been recovered from food animals, patients, and healthy humans, transmission of mcr genes at the animal-human interface remains largely unknown. This was the first study to isolate and characterize MCR-producing isolates from mink, as well as to report the coexistence of two different MCR-1 producers in the same farmer. The characterization and analysis of two MCR-1-producing E. coli isolates may have important implications for comprehension of the transmission dynamics of these bacteria. We emphasize the importance of improved multisectorial surveillance of colistin-resistant E. coli in this region.
Project description:The American mink (Neovison vison) is a semiaquatic species of mustelid native to North America. It's an important animal for the fur industry. Many efforts have been made to locate genes influencing fur quality and color, but this search has been impeded by the lack of a reference genome. Here we present the first draft genome of mink. In our study, two mink individuals were sequenced by Illumina sequencing with 797?Gb sequence generated. Assembly yielded 7,175 scaffolds with an N50 of 6.3?Mb and length of 2.4?Gb including gaps. Repeat sequences constitute around 31% of the genome, which is lower than for dog and cat genomes. The alignments of mink, ferret and dog genomes help to illustrate the chromosomes rearrangement. Gene annotation identified 21,053 protein-coding sequences present in mink genome. The reference genome's structure is consistent with the microsatellite-based genetic map. Mapping of well-studied genes known to be involved in coat quality and coat color, and previously located fur quality QTL provide new knowledge about putative candidate genes for fur traits. The draft genome shows great potential to facilitate genomic research towards improved breeding for high fur quality animals and strengthen our understanding on evolution of Carnivora.
Project description:Characterizing the genetic structure and population history can facilitate the development of genomic breeding strategies for the American mink. In this study, we used the whole genome sequences of 100 mink from the Canadian Centre for Fur Animal Research (CCFAR) at the Dalhousie Faculty of Agriculture (Truro, NS, Canada) and Millbank Fur Farm (Rockwood, ON, Canada) to investigate their population structure, genetic diversity and linkage disequilibrium (LD) patterns. Analysis of molecular variance (AMOVA) indicated that the variation among color-types was significant (<i>p</i> < 0.001) and accounted for 18% of the total variation. The admixture analysis revealed that assuming three ancestral populations (K = 3) provided the lowest cross-validation error (0.49). The effective population size (<i>Ne</i>) at five generations ago was estimated to be 99 and 50 for CCFAR and Millbank Fur Farm, respectively. The LD patterns revealed that the average <i>r</i><sup>2</sup> reduced to <0.2 at genomic distances of >20 kb and >100 kb in CCFAR and Millbank Fur Farm suggesting that the density of 120,000 and 24,000 single nucleotide polymorphisms (SNP) would provide the adequate accuracy of genomic evaluation in these populations, respectively. These results indicated that accounting for admixture is critical for designing the SNP panels for genotype-phenotype association studies of American mink.
Project description:Fur Animal Epidemic Necrotic Pyoderma (FENP) is a severe, often lethal infectious disease affecting all three fur animal species: mink (Neovision vision), foxes (Vulpes lagopus) and finnraccoons (Nyctereutes procyonoides). Previous studies showed an association between Arcanobacterium phocae and FENP. An experimental infection was conducted to confirm the ability of A. phocae to infect mink either alone or concurrently with a novel Streptococcus sp. found together with A. phocae in many cases of FENP. Different inoculation methods were tested to study possible routes of transmission. Typical signs, and gross- and histopathological findings for FENP were detected when naïve mink were infected with the tissue extract of mink with FENP, using a subcutaneous/ intradermal infection route. Edema, hemorrhage, necrosis and pus formation were detected in the infection site. A pure culture preparation of A. phocae alone or concurrently with the novel Streptococcus sp. caused severe acute signs of lethargy, apathy and anorexia and even mortality. The histopathological findings were similar to those found in naturally occurring cases of FENP. In contrast, the perorally infected mink presented no clinical signs nor any gross- or histopathological lesions. This study showed that A. phocae is able to cause FENP. The study also indicated that predisposing factors such as the environment, the general condition of the animals, temperature and skin trauma contribute to the development of the disease.
Project description:Pseudorabies, a highly contagious infectious disease of swine is caused by pseudorabies virus (PRV). PRV can cause fatal infection in other animal species.We report a deadly outbreak of pseudorabies that killed 87.2% (3522/4028) minks in a farm in 2014 in Shandong Province, China. PRV was isolated by using Vero cell culture and detected in mink samples by PCR from minks died during the outbreak. Epidemiological analysis indicated that 5.8% of minks (33/566) were PCR positive to PRV in Shandong Province. Phylogenetic analysis indicated that the PRV strains isolated from minks in this study were in the same clade with the Chinese porcine PRV isolates, which are resistant to the PRV vaccine.We demonstrated that pseudorabies virus caused an outbreak of minks in a farm in Shandong Province of China and the virus has a very high infection rate in minks in Shandong Province, which is a challenge for the fur industry in China.
Project description:The fur colour of American mink (Neovison vison) involves over 35 traits, but only three of these have been linked to specific genes. Despite being the most popular, coat colours Silverblue and Hedlund white remain uncharacterized genetically. The former is the first genetic mutant of fur colour identified in minks, while the latter is a commercially valuable phenotype that can be dyed easily. Here, we performed the whole genome sequencing for two American mink breeds with Silverblue and Hedlund white coats. We identified mutations in splice donor sites of genes coding melanophilin (MLPH) and microphthalmia-associated transcription factor (MITF) that regulate melanosome transport and neural-crest-derived melanocyte development, respectively. Both mutations cause mRNA splicing impairments that lead to a shift in open reading frames of MLPH and MITF. We conclude that our data should be useful for tracking economically valuable fur traits in mink breeding programs to contribute to global fur production.
Project description:Farmed mink (Neovison vison) is one of the most important fur-bearing species worldwide, and coat colour is a crucial qualitative characteristic that contributes to the economic value of the fur. To identify additional genes that may play important roles in coat colour regulation, Illumina/Solexa high-throughput sequencing technology was used to catalogue the global gene expression profiles in mink skin with two different coat colours (black and white). RNA-seq analysis indicated that a total of 12,557 genes were differentially expressed in black versus white minks, with 3,530 genes up-regulated and 9,027 genes down-regulated in black minks. Significant differences were not observed in the expression of MC1R and TYR between the two different coat colours, and the expression of ASIP was not detected in the mink skin of either coat colour. The expression levels of KITLG, LEF1, DCT, TYRP1, PMEL, Myo5a, Rab27a and SLC7A11 were validated by qRT-PCR, and the results were consistent with RNA-seq analysis. This study provides several candidate genes that may be associated with the development of two coat colours in mink skin. These results will expand our understanding of the complex molecular mechanisms underlying skin physiology and melanogenesis in mink and will provide a foundation for future studies.
Project description:BACKGROUND:Identification of genes underlying production traits is a key aim of the mink research community. Recent availability of genomic tools have opened the possibility for faster genetic progress in mink breeding. Availability of mink genome assembly allows genome-wide association studies in mink. RESULTS:In this study, we used genotyping-by-sequencing to obtain single nucleotide polymorphism (SNP) genotypes of 2496 mink. After multiple rounds of filtering, we retained 28,336 high quality SNPs and 2352 individuals for a genome-wide association study (GWAS). We performed the first GWAS for body weight, behavior, along with 10 traits related to fur quality in mink. CONCLUSIONS:Combining association results with existing functional information of genes and mammalian phenotype databases, we proposed WWC3, MAP2K4, SLC7A1 and USP22 as candidate genes for body weight and pelt length in mink.
Project description:Transmissible spongiform encephalopathies (TSEs) are diagnosed by immunodetection of disease-associated prion protein (PrP(d)). The distribution of PrP(d) within the body varies with the time-course of infection and between species, during interspecies transmission, as well as with prion strain. Mink are susceptible to a form of TSE known as transmissible mink encephalopathy (TME), presumed to arise due to consumption of feed contaminated with a single prion strain of ruminant origin. After extended passage of TME isolates in hamsters, two strains emerge, HY and DY, each of which is associated with unique structural isoforms of PrP(TME) and of which only the HY strain is associated with accumulation of PrP(TME) in lymphoid tissues. Information on the structural nature and lymphoid accumulation of PrP(TME) in mink is limited. In this study, 13 mink were challenged by intracerebral inoculation using late passage TME inoculum, after which brain and lymphoid tissues were collected at preclinical and clinical time points. The distribution and molecular nature of PrP(TME) was investigated by techniques including blotting of paraffin wax-embedded tissue and epitope mapping by western blotting. PrP(TME) was detected readily in the brain and retropharyngeal lymph node during preclinical infection, with delayed progression of accumulation within other lymphoid tissues. For comparison, three mink were inoculated by the oral route and examined during clinical disease. Accumulation of PrP(TME) in these mink was greater and more widespread, including follicles of rectoanal mucosa-associated lymphoid tissue. Western blot analyses revealed that PrP(TME) accumulating in the brain of mink is structurally most similar to that accumulating in the brain of hamsters infected with the DY strain. Collectively, the results of extended passage in mink are consistent with the presence of only a single strain of TME, the DY strain, capable of inducing accumulation of PrP(TME) in the lymphoid tissues of mink but not in hamsters. Thus, mink are a relevant animal model for further study of this unique strain, which ultimately may have been introduced through consumption of a TSE of ruminant origin.