Sudan Black B masks Mycobacterium avium subspecies paratuberculosis immunofluorescent antibody labeling

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Phenotypes of macrophages present in the intestine are impacted by stage of disease in cattle naturally infected with Mycobacterium avium subsp. paratuberculosis

Macrophages play an important role in the host immune response to Mycobacterium avium subsp. paratuberculosis (MAP) infection, however, MAP is able to disrupt normal macro- phage functions to avoid destruction. It is unclear whether the phenotypes of macrophages present in the target tissue play a role in the inability to clear MAP infection. The aim of this study was to identify macrophage phenotypes (host defense or resolution and repair) present within the bovine ileum of naturally infected cattle, as well as to ascertain abundance of each macrophage phenotype present during different stages of MAP infection. Immunofluo- rescent (IF) labeling was performed on frozen bovine mid-ileal tissue sections collected from 28 Holstein dairy cows. Comprehensive IF staining for cytokines, such as IFN-γ, IL- 1Ra, IL-1β, IL-10, TGF-β, TNF-α, and uNOS, along with markers such as CD163, CD206, and TLR4, served to define the macrophage phenotypes. Overall, cows in the clinical stage of disease demonstrated significantly higher numbers of resolution and repair macrophages and lower numbers of host defense macrophages in the ileal tissue. Interestingly, subclinically affected cows with asymptomatic disease had a nearly equal ratio of host defense and resolution and repair macrophage phenotypes, whereas macrophage phenotype was skewed to a host defense macrophage in the tissues of the control noninfected cows. The preponderance of M2-like resolution and repair phenotype for macrophages in the tissues of cows with clinical disease would explain why the host fails to control and/or clear the infection, leading to a higher MAP burden. The results of the current study offer insight into the disparate macrophage phenotypes present in the bovine ileum during different stages of infection

Quantification of Macrophages and Mycobacterium avium Subsp. paratuberculosis in Bovine Intestinal Tissue During Different Stages of Johne’s Disease

Johne’s disease is an enteric disease caused by the intracellular pathogen Mycobacterium avium subsp. paratuberculosis (MAP). Upon ingestion of MAP, it is translocated across the intestinal epithelium and may be killed by intestinal macrophages, or depending on the bacterial burden and immunological status of the animal, MAP may thwart innate defense mechanisms and persist within the macrophage. This study aimed to determine the numbers of macrophages and MAP present in bovine midileal tissue during different stages of infection. Immunofluorescent (IF) labeling was performed on frozen bovine midileal intestinal tissue collected from 28 Holstein dairy cows. The number of macrophages in midileal tissue sections was higher for clinically affected cows, followed by subclinically affected cows and then uninfected control cows. Macrophages were present throughout the tissue sections in clinical cows, including the tunica muscularis, submucosa, and the lamina propria around the crypts and in the villous tips, with progressively fewer macrophages in subclinically affected and control cows. Clinically affected cows also demonstrated significantly higher numbers of MAP and higher numbers of macrophages with intracellular MAP compared to subclinically affected cows. MAP IF labeling was present within the submucosa and lamina propria around the crypts, progressing into the villous tips in some clinically affected cows. Our findings indicate that number of macrophages increases with progression of infection, but a significant number of the macrophages present in the midileum are not associated with MAP

Boer goats appear to lack a functional IgA and eosinophil response against natural nematode infection

Gastrointestinal nematode infection is one of the major diseases affecting small ruminants. Although some breeds of goats are quite resistant, many breeds of goats are relatively susceptible. This study used a combined parasitological, immunological, bioinformatic and statistical approach to examine the role of goat IgA and eosinophils in protection against Teladorsagia circumcincta. Molecular modelling suggested that the transmembrane domain of the high affinity IgA receptor was dysfunctional in goats. Statistical analyses failed to find any association in naturally infected goats between high IgA or eosinophil responses and low faecal egg counts. Together these results indicate that IgA and eosinophil responses against T. circumcincta are less effective in goats than sheep

Kinetics of IgA and eosinophils following a low‐dose, predominantly Haemonchus contortus infection of Boer goats

Aims: Most breeds of goat are more susceptible to nematode infection than sheep and this appears to be a consequence of less effective immune responses. Several papers have considered the effectiveness of eosinophils and Immunoglobulin A (IgA) in goats but differences in the induction of responses have not been studied in the same detail. The aim of this study was to look at the induction of eosinophil and IgA responses in Boer goats reared indoors under intensive conditions. Methods and results: The goats were experimentally infected with a low dose of 2400 Haemonchus contortus, Trichostrongylus spp. and Oesophagostomum spp. at a 6:1:1 ratio. Faecal egg counts (FEC), packed cell volume (PCV), IgA activity against third‐stage larvae and peripheral eosinophilia were measured twice a week for eight weeks. The infection generated an IgA response but did not significantly increase peripheral eosinophilia in the 25 infected kids compared to the 4 control animals. FEC was not associated with IgA activity or eosinophilia. Conclusion: A detailed analysis of IgA and eosinophil responses to deliberate nematode infection in Boer goats showed that there was an increase in nematode‐specific IgA activity but no detectable eosinophil response. In addition, there was no association between increased IgA activity or eosinophilia with egg counts and worm burdens. These suggest that IgA and eosinophils do not act to control nematode infection in goats

Kinetics of IgA and eosinophils following a low-dose, predominantly Haemonchus contortus infection of Boer goats

Aims: Most breeds of goat are more susceptible to nematode infection than sheep, and this appears to be a consequence of less effective immune responses. Several papers have considered the effectiveness of eosinophils and immunoglobulin A (IgA) in goats but differences in the induction of responses have not been studied in the same detail. The aim of this study was to look at the induction of eosinophil and IgA responses in Boer goats reared indoors under intensive conditions. Method and results: The goats were experimentally infected with a low dose of 2400 Haemonchus contortus, Trichostrongylus spp. and Oesophagostomum spp. at a 6:1:1 ratio. Faecal egg counts (FEC), packed cell volume (PCV), IgA activity against third-stage larvae and peripheral eosinophilia were measured twice a week for eight weeks. The infection generated an IgA response but did not significantly increase peripheral eosinophilia in the 25 infected kids compared with the 4 control animals. FEC was not associated with IgA activity or eosinophilia. Conclusion: A detailed analysis of IgA and eosinophil responses to deliberate nematode infection in Boer goats showed that there was an increase in nematode-specific IgA activity but no detectable eosinophil response. In addition, there was no association between increased IgA activity or eosinophilia with egg counts and worm burdens. These suggest that IgA and eosinophils do not act to control nematode infection in goats

Phenotypes of macrophages present in the intestine are impacted by stage of disease in cattle naturally infected with Mycobacterium avium subsp. paratuberculosis

Macrophages play an important role in the host immune response to Mycobacterium avium subsp. paratuberculosis (MAP) infection, however, MAP is able to disrupt normal macro- phage functions to avoid destruction. It is unclear whether the phenotypes of macrophages present in the target tissue play a role in the inability to clear MAP infection. The aim of this study was to identify macrophage phenotypes (host defense or resolution and repair) present within the bovine ileum of naturally infected cattle, as well as to ascertain abundance of each macrophage phenotype present during different stages of MAP infection. Immunofluo- rescent (IF) labeling was performed on frozen bovine mid-ileal tissue sections collected from 28 Holstein dairy cows. Comprehensive IF staining for cytokines, such as IFN-γ, IL- 1Ra, IL-1β, IL-10, TGF-β, TNF-α, and uNOS, along with markers such as CD163, CD206, and TLR4, served to define the macrophage phenotypes. Overall, cows in the clinical stage of disease demonstrated significantly higher numbers of resolution and repair macrophages and lower numbers of host defense macrophages in the ileal tissue. Interestingly, subclinically affected cows with asymptomatic disease had a nearly equal ratio of host defense and resolution and repair macrophage phenotypes, whereas macrophage phenotype was skewed to a host defense macrophage in the tissues of the control noninfected cows. The preponderance of M2-like resolution and repair phenotype for macrophages in the tissues of cows with clinical disease would explain why the host fails to control and/or clear the infection, leading to a higher MAP burden. The results of the current study offer insight into the disparate macrophage phenotypes present in the bovine ileum during different stages of infection

Online Relinquishments of Dogs and Cats in Australia

While traditionally people relinquish their pets to an animal shelter or pound, the internet provides a newer method to re-home. We analyzed advertisements (ads) on the largest website in Australia for trading dogs and cats: Gumtree. Data was collected in 2016. Dogs were sampled on 7, 16 and 24 February 2016 and cats on 9, 19 and 26 February 2016, with 2640 ads for relinquished dogs, and 2093 ads for relinquished cats. It was estimated >31,000 puppies/dogs and >24,000 kittens/cats are relinquished on Gumtree per year. The median age of dogs was 1.42 and cats 0.9 years of age. There were 23% of dog ads and 62% of cat ads for free animals. Compared to the human population, there were proportionately more ads in Queensland and fewer ads in Victoria. A total of 15 people were surveyed who had relinquished a dog or cat using Gumtree. The dog owners used Gumtree for two reasons: because they believed the shelters were full (n = 4); and they wanted to see/interview the new owner (n = 2). For cat owners: they had originally got the cat on Gumtree (n = 2); they use Gumtree for other things, and it works (n = 2), and; they wanted to see/interview the new owner (n = 2). The data collected will be valuable for implementation of policy and interventions to protect the welfare of unwanted dogs and cats

Quantification of Macrophages and Mycobacterium avium Subsp. paratuberculosis in Bovine Intestinal Tissue During Different Stages of Johne’s Disease

Johne’s disease is an enteric disease caused by the intracellular pathogen Mycobacterium avium subsp. paratuberculosis (MAP). Upon ingestion of MAP, it is translocated across the intestinal epithelium and may be killed by intestinal macrophages, or depending on the bacterial burden and immunological status of the animal, MAP may thwart innate defense mechanisms and persist within the macrophage. This study aimed to determine the numbers of macrophages and MAP present in bovine midileal tissue during different stages of infection. Immunofluorescent (IF) labeling was performed on frozen bovine midileal intestinal tissue collected from 28 Holstein dairy cows. The number of macrophages in midileal tissue sections was higher for clinically affected cows, followed by subclinically affected cows and then uninfected control cows. Macrophages were present throughout the tissue sections in clinical cows, including the tunica muscularis, submucosa, and the lamina propria around the crypts and in the villous tips, with progressively fewer macrophages in subclinically affected and control cows. Clinically affected cows also demonstrated significantly higher numbers of MAP and higher numbers of macrophages with intracellular MAP compared to subclinically affected cows. MAP IF labeling was present within the submucosa and lamina propria around the crypts, progressing into the villous tips in some clinically affected cows. Our findings indicate that number of macrophages increases with progression of infection, but a significant number of the macrophages present in the midileum are not associated with MAP

Prediction of Johne’s disease state based on quantification of T cell markers and their interaction with macrophages in the bovine intestine

International audienceAbstractCell-mediated immune responses to Mycobacterium avium subsp. paratuberculosis (MAP) are regulated by various types of T lymphocytes. The aim of this study was to quantitate T cell subsets in the mid-ileum of cows naturally infected with MAP to identify differences during different stages of infection, and to determine whether these subsets could be used as predictors of disease state. Immunofluorescent labeling of T cell subsets and macrophages was performed on frozen mid-ileal tissue sections archived from naturally infected dairy cows in either subclinical or clinical disease status, and noninfected control cows. Comprehensive IF staining for CD4, CD8α, TcR1-N24 (gamma delta), FoxP3, CXCR3 and CCR9 served to define T cell subsets and was correlated with macrophages present. Clinically affected cows demonstrated significantly higher numbers of CXCR3+ (Th1-type) and CCR9+ (total small intestinal lymphocytes) cells at the site of infection compared to the subclinical cows and noninfected controls. Further, predictive modeling indicated a significant interaction between CXCR3+ and AM3K+ (macrophages) cells, suggesting that progression to clinical disease state aligns with increased numbers of these cell types at the site of infection. The ability to predict disease state with this model was improved from previous modeling using immunofluorescent macrophage data. Predictive modelling indicated an interaction between CXCR3+ and AM3K+ cells, which could more sensitively detect subclinical cows compared to clinical cows. It may be possible to use this knowledge to improve and develop an assay to detect subclinically infected animals with more confidence during the early stages of the disease