| 1. |
- Fuxelius, Hans-Henrik, et al.
(författare)
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Camel Streptococcus agalactiae populations are associated with specific disease complexes and acquired the tetracycline resistance gene tetM via a Tn916-like element
- 2013
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Ingår i: Veterinary Research. - : Springer Science and Business Media LLC. - 0928-4249 .- 1297-9716. ; 44
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Tidskriftsartikel (refereegranskat)abstract
- Camels are the most valuable livestock species in the Horn of Africa and play a pivotal role in the nutritional sustainability for millions of people. Their health status is therefore of utmost importance for the people living in this region. Streptococcus agalactiae, a Group B Streptococcus (GBS), is an important camel pathogen. Here we present the first epidemiological study based on genetic and phenotypic data from African camel derived GBS. Ninety-two GBS were characterized using multilocus sequence typing (MLST), capsular polysaccharide typing and in vitro antimicrobial susceptibility testing. We analysed the GBS using Bayesian linkage, phylogenetic and minimum spanning tree analyses and compared them with human GBS from East Africa in order to investigate the level of genetic exchange between GBS populations in the region. Camel GBS sequence types (STs) were distinct from other STs reported so far. We mapped specific STs and capsular types to major disease complexes caused by GBS. Widespread resistance (34%) to tetracycline was associated with acquisition of the tetM gene that is carried on a Tn916-like element, and observed primarily among GBS isolated from mastitis. The presence of tetM within different MLST clades suggests acquisition on multiple occasions. Wound infections and mastitis in camels associated with GBS are widespread and should ideally be treated with antimicrobials other than tetracycline in East Africa.
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| 2. |
- Wille, Michelle, et al.
(författare)
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Infected or not : are PCR-positive oropharyngeal swabs indicative of low pathogenic influenza A virus infection in the respiratory tract of Mallard Anas platyrhynchos?
- 2014
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Ingår i: Veterinary research (Print). - : Springer Science and Business Media LLC. - 0928-4249 .- 1297-9716. ; 45, s. Article ID: 53-
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Tidskriftsartikel (refereegranskat)abstract
- Detection of influenza virus in oropharyngeal swabs collected during wild bird surveillance is assumed to representrespiratory infection, although intestine is the main site of infection. We tested this assumption by histologicalexamination of the respiratory tract of wild Mallards with virus-positive oropharyngeal swabs. Thirty-two of 125Mallards tested had viral-RNA positive oropharyngeal swabs. The respiratory tracts of four Mallards with the mostvirus were examined in detail by immunohistochemistry. None had detectable virus antigen in the respiratory tract,suggesting it was not infected. An alternative explanation is that the oropharynx was contaminated with virusthrough feeding in surface water or through preening.
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| 3. |
- Aboshady, Hadeer Moursy, et al.
(författare)
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Dynamic transcriptomic changes of goat abomasal mucosa in response to Haemonchus contortus infection
- 2020
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Ingår i: Veterinary Research. - : Springer Science and Business Media LLC. - 0928-4249 .- 1297-9716. ; 51
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Tidskriftsartikel (refereegranskat)abstract
- Gastrointestinal nematode (GIN) infections are one of the major constraints for grazing sheep and goat production worldwide. Genetic selection for resistant animals is a promising control strategy. Whole-transcriptome analysis via RNA-sequencing (RNA-seq) provides knowledge of the mechanisms responsible for complex traits such as resistance to GIN infections. In this study, we used RNA-seq to monitor the dynamics of the response of the abomasal mucosa of Creole goat kids infected with Haemonchus contortus by comparing resistant and susceptible genotypes. A total of 8 cannulated kids, 4 susceptible and 4 resistant to GIN, were infected twice with 10 000 L3 H. contortus. During the second infection, abomasal mucosal biopsies were collected at 0, 8, 15 and 35 days post-infection (dpi) from all kids for RNA-seq analysis. The resistant animals showed early activation of biological processes related to the immune response. The top 20 canonical pathways of differentially expressed genes for different comparison showed activation of the immune response through many relevant pathways including the Th1 response. Interestingly, our results showed a simultaneous time series activation of Th2 related genes in resistant compared to susceptible kids.
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| 4. |
- Ahlberg, Viktor, et al.
(författare)
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Innate immune responses induced by the saponin adjuvant Matrix-M in specific pathogen free pigs
- 2017
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Ingår i: Veterinary Research. - : Springer Science and Business Media LLC. - 0928-4249 .- 1297-9716. ; 48
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Tidskriftsartikel (refereegranskat)abstract
- Saponin-based adjuvants have been widely used to enhance humoral and cellular immune responses in many species, but their mode of action is not fully understood. A characterization of the porcine transcriptional response to Matrix-M was performed in vitro using lymphocytes, monocytes or monocyte-derived dendritic cells (MoDCs) and in vivo. The effect of Matrix-M was also evaluated in specific pathogen free (SPF) pigs exposed to conventionally reared pigs. The pro-inflammatory cytokine genes IL1B and CXCL8 were up-regulated in monocytes and lymphocytes after Matrix-M exposure. Matrix-M also induced IL12B, IL17A and IFNG in lymphocytes and IFN-a gene expression in MoDCs. Several genes were indicated as up-regulated by Matrix-M in blood 18 h after injection, of which the genes for IFN-a and TLR2 could be statistically confirmed. Respiratory disease developed in all SPF pigs mixed with conventional pigs within 1-3 days. Two out of four SPF pigs injected with saline prior to contact exposure displayed systemic symptoms that was not recorded for the four pigs administered Matrix-M. Granulocyte counts, serum amyloid A levels and transcription of IL18 and TLR2 coincided with disease progression in the pigs. These results support further evaluation of Matrix-M as a possible enhancer of innate immune responses during critical moments in pig management.
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| 5. |
- Dahlberg, Josef, et al.
(författare)
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Absence of changes in the milk microbiota during Escherichia coli endotoxin induced experimental bovine mastitis
- 2023
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Ingår i: Veterinary research (Print). - : BioMed Central (BMC). - 0928-4249 .- 1297-9716. ; 54
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Tidskriftsartikel (refereegranskat)abstract
- Changes in the milk microbiota during the course of mastitis are due to the nature of a sporadic occurring disease difficult to study. In this study we experimentally induced mastitis by infusion of Escherichia coli endotoxins in one udder quarter each of nine healthy lactating dairy cows and assessed the bacteriological dynamics and the milk microbiota at four time points before and eight time points after infusion. As control, saline was infused in one udder quarter each of additionally nine healthy cows that followed the same sampling protocol. The milk microbiota was assessed by sequencing of the 16 S rRNA gene and a range of positive and negative controls were included for methodological evaluation. Two different data filtration models were used to identify and cure data from contaminating taxa. Endotoxin infused quarters responded with transient clinical signs of inflammation and increased SCC while no response was observed in the control cows. In the milk microbiota data no response to inflammation was identified. The data analysis of the milk microbiota was largely hampered by laboratory and reagent contamination. Application of the filtration models caused a marked reduction in data but did not reveal any associations with the inflammatory reaction. Our results indicate that the microbiota in milk from healthy cows is unaffected by inflammation.
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| 6. |
- Gavier Widén, Dolores
(författare)
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Heterogeneity of pathological prion protein accumulation in the brain of moose (Alces alces) from Norway, Sweden and Finland with chronic wasting disease
- 2023
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Ingår i: Veterinary Research. - 0928-4249 .- 1297-9716. ; 54
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Tidskriftsartikel (refereegranskat)abstract
- Prion diseases are a group of neurodegenerative, transmissible, and fatal disorders that affect several animal species. They are characterized by the conformational conversion of the cellular prion protein (PrPC) into the pathological prion protein (PrPSc). In 2016, chronic wasting disease (CWD) gained great importance at European level due to the first disease detection in a wild reindeer (Rangifer tarandus) in Norway. The subsequent intensive CWD surveillance launched in cervids resulted in the detection of CWD in moose (Alces alces), with 11 cases in Norway, 3 in Finland and 4 in Sweden. These moose cases differ considerably from CWD cases in North American and reindeer in Norway, as PrPSc was detectable in the brain but not in lymphoid tissues. These facts suggest the occurrence of a new type of CWD. Here, we show some immunohistochemical features that are clearly different from CWD cases in North American and Norwegian reindeer. Further, the different types of PrPSc deposits found among moose demonstrate strong variations between the cases, supporting the postulation that these cases could carry multiple strains of CWD.
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| 7. |
- Günther, Juliane, et al.
(författare)
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Assessment of the immune capacity of mammary epithelial cells : comparison with mammary tissue after challenge with Escherichia coli
- 2009
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Ingår i: Veterinary research (Print). - Les Ulis Cedex A, France : EDP Sciences. - 0928-4249 .- 1297-9716. ; 40:4
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Tidskriftsartikel (refereegranskat)abstract
- We examined the repertoire and extent of inflammation dependent gene regulation in a bovine mammary epithelial cell (MEC) model, to better understand the contribution of the MEC in the immune defence of the udder. We challenged primary cultures of MEC from cows with heat inactivated Escherichia coli pathogens and used Affymetrix DNA-microarrays to profile challenge related alterations in their transcriptome. Compared to acute mastitis, the most prominently activated genes comprise those encoding chemokines, interleukins, beta-defensins, serum amyloid A and haptoglobin. Hence, the MEC exert sentinel as well as effector functions of innate immune defence. E. coli stimulated a larger fraction of genes (30%) in the MEC belonging to the functional category Inflammatory Response than we recorded with the same microarrays during acute mastitis in the udder (17%). This observation underscores the exquisite immune capacity of MEC. To more closely examine the adequacy of immunological regulation in MEC, we compared the inflammation dependent regulation of factors contributing to the complement system between the udder versus the MEC. In the MEC we observed only up regulation of several complement factor-encoding genes. Mastitis, in contrast, in the udder strongly down regulates such genes encoding factors contributing to both, the classical pathway of complement activation and the Membrane Attack Complex, while the expression of factors contributing to the alternative pathway may be enhanced. This functionally polarized regulation of the complex complement pathway is not reflected in the MEC models.
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| 8. |
- Hellman, Stina, et al.
(författare)
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Equine enteroid-derived monolayers recapitulate key features of parasitic intestinal nematode infection
- 2024
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Ingår i: Veterinary research (Print). - : Springer Nature. - 0928-4249 .- 1297-9716. ; 55:1
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Tidskriftsartikel (refereegranskat)abstract
- Stem cell-derived organoid cultures have emerged as attractive experimental models for infection biology research regarding various types of gastro-intestinal pathogens and host species. However, the large size of infectious nematode larvae and the closed structure of 3-dimensional organoids often hinder studies of the natural route of infection. To enable easy administration to the apical surface of the epithelium, organoids from the equine small intestine, i.e. enteroids, were used in the present study to establish epithelial monolayer cultures. These monolayers were functionally tested by stimulation with IL-4 and IL-13, and/or exposure to infectious stage larvae of the equine nematodes Parascaris univalens, cyathostominae and/or Strongylus vulgaris. Effects were recorded using transcriptional analysis combined with histochemistry, immunofluorescence-, live-cell- and scanning electron microscopy. These analyses revealed heterogeneous monolayers containing both immature and differentiated cells including tuft cells and mucus-producing goblet cells. Stimulation with IL-4/IL-13 increased tuft- and goblet cell differentiation as demonstrated by the expression of DCLK1 and MUC2. In these cytokine-primed monolayers, the expression of MUC2 was further promoted by co-culture with P. univalens. Moreover, live-cell imaging revealed morphological alterations of the epithelial cells following exposure to larvae even in the absence of cytokine stimulation. Thus, the present work describes the design, characterization and usability of an experimental model representing the equine nematode-infected small intestinal epithelium. The presence of tuft cells and goblet cells whose mucus production is affected by Th2 cytokines and/or the presence of larvae opens up for mechanistic studies of the physical interactions between nematodes and the equine intestinal mucosa.
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| 9. |
- Hellman, Stina
(författare)
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Generation of equine enteroids and enteroid-derived 2D monolayers that are responsive to microbial mimics
- 2021
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Ingår i: Veterinary Research. - : Springer Science and Business Media LLC. - 0928-4249 .- 1297-9716. ; 52
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Tidskriftsartikel (refereegranskat)abstract
- Enteroid cultures are three-dimensional in vitro models that reflect the cellular composition and architecture of the small intestine. One limitation with the enteroid conformation is the enclosed lumen, making it difficult to expose the apical surface of the epithelium to experimental treatments. The present study was therefore conducted to generate cultures of equine enteroids and to develop methods for culture of enteroid-derived cells on a two-dimensional plane, enabling easy access to the apical surface of the epithelium. Equine enteroids were established from small intestinal crypts within 7-9 days of culture. Transcriptional analysis of cell type markers confirmed the presence of enterocytes, stem-, Paneth-, proliferative-, enteroendocrine-, goblet- and tuft cells. This cellular composition was maintained over multiple passages, showing that the enteroids can be kept for prolonged periods. The transfer from 3D enteroids to 2D monolayers slightly modified the relative expression levels of the cell type markers, indicating a decrease of goblet- and Paneth cells in the monolayers. Stimulation with the TLR2, 3 and 4 agonists Pam3CSK4, Poly I:C and LPS, respectively, induced the pro-inflammatory cytokines TNF-alpha and IL-8, while the TLR5 agonist FliC only induced TNF-alpha. In addition, an up-regulation of TGF-beta, IL-33 and IFN-beta was recorded after exposure to lipofected Poly I:C that also affected the monolayer integrity. Thus, the equine enteroid-derived 2D monolayers described in the present study show both genetic and functional similarities with the equine intestine making it an interesting in vitro model for studies demanding access to the apical surface, e.g. in studies of host-microbe interactions.
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| 10. |
- Hellman, Stina, et al.
(författare)
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The adjuvant G3 promotes a Th1 polarizing innate immune response in equine PBMC
- 2018
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Ingår i: Veterinary Research. - : Springer Science and Business Media LLC. - 0928-4249 .- 1297-9716. ; 49
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Tidskriftsartikel (refereegranskat)abstract
- The immunomodulatory effect of a new particulate adjuvant, G3, alone or in combination with agonists to TLR2/1 or TLR5 was evaluated in cultures of equine PBMC. Exposure to the G3 adjuvant up-regulated genes encoding IFN-, IL-1, IL-6, IL-8, IL-12p40 and IL-23p19 in the majority of the horses tested, indicating that the G3 adjuvant induced a pro-inflammatory and Th1 dominated profile. In accordance, genes encoding IL-13, IL-4, IL-10 and TGF- remained unaffected and genes encoding IFN-, IL-17A and TNF- were only occasionally and weakly induced. The two TLR agonists Pam3CSK4 (TLR2/1) and FliC (TLR5) induced cytokine profiles characterized by a clear induction of IL-10 as well as up-regulation of the genes encoding IL-1, IL-6 and IL-8. The presence of G3 modified this response, in particular by reducing the FliC and Pam3CSK4 induced production of IL-10. Furthermore, G3 acted in synergy with Pam3CSK4 in enhancing the production of IFN- whereas G3 combined with FliC increased the gene expression of IL-8. Thus, the G3 adjuvant seems to have the capacity to promote a Th1 polarizing innate immune response in eqPBMC, both by favouring IFN- production and by reducing production of IL-10 induced by co-delivered molecules. These features make G3 an interesting candidate to further evaluate for its potential as an adjuvant in equine vaccines.
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