Project description:To characterize the staphylococcal cassette chromosome mec (SCCmec), virulence and antimicrobial susceptibility of Staphylococcus aureus ST130 isolated from mara (Dolichotis patagonum), a large rodent species native to South America and kept in captivity at Copenhagen Zoo.The presence of mecC was confirmed by PCR in 15 S. aureus ST130 isolated from mara during a previous study. WGS was performed on two randomly selected isolates to characterize their genomes with respect to SCCmec, virulence and resistance gene content. Antimicrobial susceptibility was tested using commercial broth microdilution tests.All the isolates belonged to spa type t528 ST130 and carried mecC. Based on WGS, mecC was 100% identical to the prototype sequence of S. aureus strain LGA251. The sequence of SCCmec type XI in the mara isolates had 23 SNPs compared with the one described in LGA251. The two sequenced strains harboured a set of virulence factors and other genomic features previously observed in ST130. Both strains carried norA as the only putative antimicrobial resistance gene in addition to mecC.Our findings support the notion that a genetically conserved mecC-carrying MRSA ST130 clone is widespread in a variety of unrelated hosts in Denmark. Since the mara at Copenhagen Zoo have limited contact with humans and other animal species, it remains unclear whether mara are natural hosts of ST130 or acquired this lineage from unknown sources. The broad host range of MRSA ST130 supports its designation as a generalist lineage.
Project description:To evaluate the long-term growth potential of BCR-ABL-transduced primitive human hematopoietic cells, lin- cord blood cells containing an MSCV-BCR-ABL-IRES-GFP (BCR-ABL) or control-GFP transgene (MIG) were injected IP into fetal goats at 45-55 days of gestation. Six transplant goats were born alive. One was examined three weeks after birth and showed GFP+ cells in the blood, bone marrow (BM), liver, kidney, lung, heart, and both skeletal and smooth muscle. FISH analysis also showed the liver of this goat contained BCR-ABL-GFP transgenic cells. The remaining five goats appear normal although, in some, the WBC count is elevated 3- to 5-fold. GFP+ cells, including cells identifiable by FACS as human CD34+ cells, have been detected in the blood of all these goats. The presence of BCR-ABL-GFP transgenic cells in the BM and liver was confirmed by FISH analysis, and quantitative real-time PCR analysis of genomic DNA isolated from unpurified BM cells obtained from three of the transplant goats demonstrated 3-5Ã104 copies of the transgene per microgram of DNA. Microarray transcript profiling was performed on blood and liver tissues of normal goats, BCR-ABL chimeric goats, MIG chimeric goats, and normal human samples. RNA for human genes was detected in goats transplanted with cord blood cells but not in normal goats, and the RNA abundance of some genes in BCR-ABL chimeric goat blood was similar to or greater than levels observed in MIG goat blood or normal human samples. Quantitative RT-PCR confirmed the differential expression of several genes in goats carrying the BCR-ABL vs. control transgene. These results demonstrate long-term engraftment but slow expansion in a large animal model of primitive human hematopoietic cells transduced with a BCR-ABL fusion gene and transplanted in utero. This novel xenotransplant goat model should be useful for analyzing the initial phases of development of human CML and for assessing new therapies with potential long-term benefits. Experiment Overall Design: Total RNA was extracted from liver (L) and blood (B) samples of normal goats (ng), humans (hu), chimeric goats engrafted with human cord blood stem cells containing control (mig) vector, and chimeric goats engrafted with CML (bcrabl) vector. RNA samples were profiled on Affymetrix human U133A GeneChips and examined for differentially expressed genes in CML vs control goats, filtering for signals significantly above background levels observed in normal goat to select for specific human gene expression.
Project description:To evaluate the long-term growth potential of BCR-ABL-transduced primitive human hematopoietic cells, lin- cord blood cells containing an MSCV-BCR-ABL-IRES-GFP (BCR-ABL) or control-GFP transgene (MIG) were injected IP into fetal goats at 45-55 days of gestation. Six transplant goats were born alive. One was examined three weeks after birth and showed GFP+ cells in the blood, bone marrow (BM), liver, kidney, lung, heart, and both skeletal and smooth muscle. FISH analysis also showed the liver of this goat contained BCR-ABL-GFP transgenic cells. The remaining five goats appear normal although, in some, the WBC count is elevated 3- to 5-fold. GFP+ cells, including cells identifiable by FACS as human CD34+ cells, have been detected in the blood of all these goats. The presence of BCR-ABL-GFP transgenic cells in the BM and liver was confirmed by FISH analysis, and quantitative real-time PCR analysis of genomic DNA isolated from unpurified BM cells obtained from three of the transplant goats demonstrated 3-5×104 copies of the transgene per microgram of DNA. Microarray transcript profiling was performed on blood and liver tissues of normal goats, BCR-ABL chimeric goats, MIG chimeric goats, and normal human samples. RNA for human genes was detected in goats transplanted with cord blood cells but not in normal goats, and the RNA abundance of some genes in BCR-ABL chimeric goat blood was similar to or greater than levels observed in MIG goat blood or normal human samples. Quantitative RT-PCR confirmed the differential expression of several genes in goats carrying the BCR-ABL vs. control transgene. These results demonstrate long-term engraftment but slow expansion in a large animal model of primitive human hematopoietic cells transduced with a BCR-ABL fusion gene and transplanted in utero. This novel xenotransplant goat model should be useful for analyzing the initial phases of development of human CML and for assessing new therapies with potential long-term benefits.
Project description:ObjectivesWe unexpectedly identified MRSA isolates carrying mecC (mecC-MRSA) from a Danish swine farm located in eastern Zealand. The objective of the present study was to investigate the origin of these isolates and their genetic relatedness to other mecC-MRSA isolates from Zealand.MethodsWGS was used to infer the phylogenetic relationship between 19 identified mecC-MRSA isolates from the swine farm and 34 additional epidemiologically unrelated human isolates from the same geographical region of Denmark. Variations in the accessory genome were investigated by bioinformatics tools, and antibiotic susceptibility profiles were assessed by MIC determination.ResultsmecC-MRSA was isolated from a domestic swine farm, but not from cattle reared at the same farm. Phylogenetic analysis revealed that all mecC-MRSA isolates from both farm animals and workers formed a separate cluster, whereas human isolates from the same municipality belonged to a closely related cluster. Analysis of the accessory genome supported this relationship.ConclusionsTo the best of our knowledge, this is the first report of mecC-MRSA isolated from domestic swine. The investigation strongly indicates that transmission of mecC-MRSA has taken place on the swine farm between the farmers and swine. The close clustering of farm isolates and isolates from the same municipality suggests a local transmission of mecC-MRSA.
Project description:Co-occurrence of benzylpenicillin-producing Trichophyton erinacei and methicillin resistant Staphylococcus aureus carrying the mecC gene on Europeaus erineaus (European hedgehog)
Project description:A new methicillin resistance gene, named mecC, was first described in 2011 in both humans and animals. Since then, this gene has been detected in different production and free-living animals and as an agent causing infections in some humans. The possible impact that these isolates can have in clinical settings remains unknown. The current available information about mecC-carrying methicillin resistant S. aureus (MRSA) isolates obtained from human samples was analyzed in order to establish its possible clinical implications as well as to determine the infection types associated with this resistance mechanism, the characteristics of these mecC-carrying isolates, their possible relation with animals and the presence of other risk factors. Until now, most human mecC-MRSA infections have been reported in Europe and mecC-MRSA isolates have been identified belonging to a small number of clonal complexes. Although the prevalence of mecC-MRSA human infections is very low and isolates usually contain few resistance (except for beta-lactams) and virulence genes, first isolates harboring important virulence genes or that are resistant to non-beta lactams have already been described. Moreover, severe and even fatal human infection cases have been detected. mecC-carrying MRSA should be taken into consideration in hospital, veterinary and food safety laboratories and in prevention strategies in order to avoid possible emerging health problems.