Phlegmonous gastritis in 2 yearling horses

Phlegmonous gastritis was diagnosed in 2 yearling fillies that were presented with a 1-wk history of fever, lethargy, and hypoproteinemia, associated with a previous diagnosis of equine proliferative enteropathy based on clinical signs and PCR assay detection of Lawsonia intracellularis in fecal samples. Abdominal ultrasound revealed enlargement of the stomach and expansion of its submucosal layer with hypoechoic fluid, as well as thickened hypomotile small intestinal segments. Given the poor prognosis and poor response to treatment, both horses were euthanized, one on the day of presentation and the other after 3 wk of intensive medical management including a combination of antimicrobials, analgesics, and intravenous colloids. At autopsy, acute mural gastritis characterized by severe submucosal edema with suppurative inflammation (i.e., phlegmonous gastritis) and necroulcerative enteritis compatible with the necrotizing form of equine proliferative enteropathy were identified in both horses. The gastric inflammation was associated with thrombosis and mixed bacterial populations, including Clostridium perfringens, that were confined to the submucosa without evidence of mucosal involvement; toxin genes compatible with C. perfringens type C were identified in one case. Human phlegmonous gastritis is an uncommon, often-fatal pyogenic infection that is often associated with mucosal injury, bacteremia, or immunocompromise. Our finding of this unusual gastric lesion in 2 horses with similar signalment, clinical disease, and spectrum of postmortem lesions suggests a similar etiopathogenesis that possibly involves local, regional, or distant hematogenous origin, and should be considered a potential complication of gastrointestinal mucosal compromise in horses.

Occurrence of Lawsonia intracellularis in horses raised in three regions of the state of Paraná, Brazil

Lawsonia intracellularis is a bacterium already described in several species and most prevalent in pigs, in which it causes enteric problems. Horses can also be affected, developing a disease known as equine proliferative enteropathy, which results from the proliferation of intestinal crypt cells in response to infection by the bacterium. Despite the existence of reports of the disease in several countries, including Brazil, there are still no reports of the disease or epidemiological studies of its occurrence in symptomatic or asymptomatic horses in the state of Paraná. Thus, the present study was conducted to examine the occurrence of L. intracellularis in asymptomatic horses raised in the west, northwest and north regions of Paraná by means of serological testing and the real-time polymerase chain reaction (qPCR) technique. In the serological approach, the immunoperoxidase monolayer assay (IPMA) technique was employed. Feces were processed and subjected to qPCR. In total, samples were collected from 162 animals from 20 farms. Of these, 9/162 (5.55%) showed specific antibodies against L. intracellularis. Real-time PCR, on the other hand, identified 7/162 (4.32%) fecal samples positive for the presence of the bacterium. When the techniques were compared, none of the samples was positive by both, demonstrating that, for a better diagnosis, they must be performed together. In contrast to most reports in horses, the present study describes higher serological and molecular occurrence in animals older than two years. These results are of great epidemiological relevance, as they indicate that the bacterium is present in the sampled regions of the state of Paraná. Therefore, the disease must be included in the differential diagnosis of diseases with similar clinical manifestations.

Review of methods for the detection of Lawsonia intracellularis infection in pigs

Lawsonia intracellularis is an obligate intracellular bacterium associated with enteric disease in pigs. Clinical signs include weight loss, diarrhea, and, in some cases, sudden death. The hallmark lesion is the thickening of the intestinal mucosa caused by increased epithelial cell replication, known as proliferative enteropathy. The immune response to L. intracellularis is not well defined, and detection of the infection, especially in the early stages, is still a significant challenge. We review here the main approaches used to identify this important but poorly understood pathogen. Detection of L. intracellularis infection as the cause of clinical disease is confounded by the high prevalence of the pathogen in many countries and that several other pathogens can produce similar clinical signs. A single L. intracellularis–specific ELISA and several amplification assays are available commercially to aid detection and surveillance, although histopathology remains the primary way to reach a conclusive diagnosis. There are major gaps in our understanding of L. intracellularis pathogenesis, especially how the host responds to infection and the factors that drive infection toward different clinical outcomes. Knowledge of pathogenesis will increase the predictive value of antemortem tests to guide appropriate interventions, including identification and treatment of subclinically affected pigs in the early stages of disease, given that this important manifestation reduces pig productivity and contributes to the economic burden of L. intracellularis worldwide.

Histopathological changes in pigs infected with ileitis

Nowadays, the ileitis (proliferative enteropathy of pigs) is one of the most common gastrointestinal diseases. The intracellular bacterium Lawsonia intracelluaris causes several forms of the disease. Histological examinations are the important stages in diagnosing and detecting profound pathological changes in sick pig organs, decreasing their productivity and causing the deaths. Swine proliferative enteropathy (SPE) has reported for the Ukraine since 2008. For SPE the early diagnostics with different test systems is relevant. We evaluated the sick, forcibly killed and dead piglets of different ages in Ukrainian pig farms during 2018-2019 in animal fattening groups. Materials were taken from piglets aged 120-150 days in farms where the ileitis was diagnosed. To assess the complex of pathological and anatomical changes detected during autopsies of piglets, V.P. Shishkov’s methods were used. Thus, we revealed a characteristic morphology of proliferative lesions. We believed that the histological examination can serve as an important diagnostic method and an alternative to direct isolation of Lawsonia intracellularis, which is very difficult to cultivate. We determined that the histopathological changes in pig organs indicated a chronic effect caused by animal pathogen. We revealed that Lawsonia intracellularis caused the profound pathological changes in pig digestive tracts, which affected the functioning of all organs and tissues of animals and lead to severe disease and possible animal death. We suggested that the histological examination is an important step in diagnosing and detecting profound pathological changes in the organs of sick pigs, which caused the decrease in their productivity and deaths.

Proliferative enteropathy caused by Lawsonia intracellularis in rabbits in Southern Brazil

Proliferative enteropathy (PE), also known as ileitis, is a disease caused by the bacterium Lawsonia intracellularis. This disease is characterized by diarrhea and ill-thrift. The aim of this study is to describe a PE outbreak in rabbits that occurred in Southern Brazil. The farm had 700 rabbits at the time the outbreak occurred. The clinical signs were severe diarrhea, dehydration, and apathy. Necropsy was performed in 33 rabbits, and the most evident macroscopic findings were thickening of the intestinal wall, intestinal loops distended by large amounts of gas, and liquid feces. Histopathological examination demonstrated a marked proliferation of enterocytes in intestinal crypts, decrease number of goblet cells, and crypts microabscesses. Silver impregnation technique (Warthin-Starry) demonstrated in intestinal crypts inside of enterocytes cytoplasm, curved vibrioid bacteria compatible with L. intracellularis. Immunohistochemical staining with anti-L. intracellularis confirmed the agent presence. PCR was performed and L. intracellularis was confirmed as the etiological agent.

The Effects of a Phytogenic Additive on the Histomorphometric Characteristics of the Intestines in Weaned Pigs with a Subclinical Natural Infection with Lawsonia intracellularis

Proliferative enteropathy, also known as proliferative ileitis, is considered to be one of the most economically important diseases in pig production worldwide. The estimated losses per affected growing pig usually range from US $1 to $5. The disease is caused by Lawsonia intracellularis, a Gram-negative, obligately intracellular bacterium. Control of the disease can be achieved with the use of vaccines or antibiotics. Recently there has been an increase in the efforts in the control of certain pathologies of the digestive system with phytogenic additives. The aim of this work was to assess the effects of a phytogenic additive on the histomorphometric characteristics of the intestines in weaned pigs with a subclinical infection with L. intracellularis acquired spontaneously. Histomorphometry analysis showed that crypt depth was significantly shorter (P<0.05), and the villus-height-to-crypt-depth ratio (P<0.05) significantly greater in the treatment group than the control. This improvement in the histological parameters of the intestine, considered to be indicators of its health, proved the positive effect of the tested additive on the digestive system in pigs.

Sero-prevalence of serological of Lawsonia intracellularis in domestic pigs in South Korea

Proliferative enteropathy (PE) of pigs mainly been caused by Lawsonia intracellularis. To investigate the prevalence of L. intracellularis in South Korea, serum samples of 2,356 pigs from nine province domestic farms were tested using IgGs against ELISA kit. During 2017 to 2019, among of every age groups, the older age groups (>120days and sow) had significant higher positive rates than younger groups. The objective of the current study was to measure the seroprevalence of antibodies to L. intracellularis in different age groups in pigs in South Korea as a more sensitive measure of detection in this country. Keywords: Lawsonia intracellularis; Elisa; Age groups; Domestic farm; South Korea

Sero-prevalence of serological of Lawsonia intracellularis in domestic pigs in South Korea

Proliferative enteropathy (PE) of pigs mainly been caused by Lawsonia intracellularis. To investigate the prevalence of L. intracellularis in South Korea, serum samples of 2,356 pigs from nine province domestic farms were tested using IgGs against ELISA kit. During 2017 to 2019, among of every age groups, the older age groups (>120days and sow) had significant higher positive rates than younger groups. The objective of the current study was to measure the seroprevalence of antibodies to L. intracellularis in different age groups in pigs in South Korea as a more sensitive measure of detection in this country. Keywords: Lawsonia intracellularis; Elisa; Age groups; Domestic farm; South Korea