lawsonia intracellularis
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2021 ◽  
Author(s):  
Lívia Mendonça Pascoal ◽  
Sarah Rodrigues Chagas ◽  
Francisco J. Pallarés ◽  
Juan J. Quereda ◽  
Juan Manuel Herrero Medrano ◽  
...  

Abstract Background: The present study aims to evaluate the efficacy of an intramuscular multivalent Escherichia coli vaccine for suckling piglets against infection not only by pathogenic E. coli but also by pathogens involved in Porcine Enteric Disease Complex (PEDC). Vaccinated Group had piglets vaccinated at days 10 and 20 of life with Colidex-C® (Vetia Animal Health, Spain), and Control Group had piglets that received sterile saline solution injection at the same days of life. We collected fecal samples in the farm from animals presenting diarrhea and intestinal mucosa swabs and ileum and colon tissue at slaughter and then performed PCR to identify E. coli virulence factors genes. Furthermore, we performed PCR to identify Lawsonia intracellularis, Brachyspira hyodisenteriae, and Salmonella spp.Results: Regarding fecal samples, 0% from Vaccinated Group was positive for E. coli, while Control Group had 94.1% of positive samples (p<0.0001). With respect to intestinal mucosa swab, 0% of the samples from Vaccinated Group were positive for E. coli, while 100% from Control Group were positive (p=0.001). Regarding ileum and colon tissue samples, 35% were positive for E. coli in Vaccinated Group and 85% in Control Group (p=0.001); Gcnt had a higher frequency of F41 (p=0.018), LT (p=0.018) and Sta (p=0.028) virulence factors genes. No sample was positive for Salmonella spp. nor for B. hyodisenteriae, but there were positive samples L. intracellularis; real-time PCR was performed and the frequencies found were 40% and 20% of ileum and colon positive samples in Vaccinated Group and 100% for ileum and 70% for colon in Control Group (p<0.001 for ileum and p=0.001 for colon).Conclusion: The results indicate that the E. coli vaccine for piglets may be a strategy to control E. coli infection. E. coli vaccines emerge as a probable strategy to help control L. intracellularis and, maybe, other enteric pathogens of pigs not evaluated in this study.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ning Xiao ◽  
Jiannan Li ◽  
Minxue Li ◽  
Yuting Hu ◽  
Huixing Lin ◽  
...  

Proliferative enteropathy (PE) is an infectious enteric disease caused by Lawsonia intracellularis (L. intracellularis) and is endemic in pig herds worldwide. However, a L. intracellularis-specific monoclonal antibody plays an important role in the evaluation of L. intracellularis infection in vitro. Therefore, the objective of this study was to produce and identify the characteristics of a new monoclonal antibody against the outer membrane protein (Omp2) of L. intracellularis and apply it in an indirect immunofluorescence assay (IFA) and immunocytochemistry (IHC). The results indicated that three highly specific monoclonal antibodies against the Omp2 protein (4D9, 3G2, and 7G5) of L. intracellularis were obtained by using purified Omp2 as an immunogen, the titers of ascitic fluids of 4D9, 3G2, and 7G5 cells were 1:2,048,000, 1:512,000, and 1:256,000, respectively. IFA analysis showed that the 4D9, 3G2, and 7G5 have no cross-reactivity with other enteric bacteria commonly found in the ilea of pigs or closely related to L. intracellularis, such as Desulfovibrio, Bilophila wadsworthia (B. wadsworthia), Salmonella choleraesuis (S. choleraesuis), Salmonella typhimurium (S. typhimurium), Escherichia coli (E. coli), and Brachyspira hyodysenteriae (B. hyodysenteriae). IFA and IHC results indicated that the monoclonal antibodies can be successfully used as primary antibodies to detect L. intracellularis in infected cells and in the crypt of the ileum from infected tissues of PE. Our findings suggested that the new monoclonal antibody specific against L. intracellularis will be useful for the evaluation of L. intracellularis infection in vivo and in vitro.


2021 ◽  
pp. 109274
Author(s):  
Minxue Li ◽  
Ning Xiao ◽  
Jiannan Li ◽  
Huixing Lin ◽  
Hongjie Fan

2021 ◽  
pp. 109264
Author(s):  
Sungwoo Park ◽  
Perumalraja Kirthika ◽  
Vijayakumar Jawalagatti ◽  
Amal Senevirathne ◽  
John Hwa Lee

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2225
Author(s):  
Jacquelyn Horsington ◽  
Maarten Witvliet ◽  
Antonius A. C. Jacobs ◽  
Ruud P. A. M. Segers

The combined application of vaccines in swine offers many benefits, including reduced time and labour costs, and improved animal welfare, due to fewer injections and manipulations. This study investigated if simultaneous intradermal vaccinations against porcine circovirus 2, porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae, and Lawsonia intracellularis, using a specialised needle-free applicator would confer comparable protection against experimental infection compared to the single vaccines. In all cases, the administration of the vaccines together was as efficacious as the administration of the vaccines alone, significantly reducing clinical signs associated with each of the four pathogens.


2021 ◽  
Vol 8 ◽  
Author(s):  
Fernando L. Leite ◽  
Brittanie Winfield ◽  
Elizabeth A. Miller ◽  
Bonnie P. Weber ◽  
Timothy J. Johnson ◽  
...  

Porcine proliferative enteropathy remains one of the most prevalent diseases in swine herds worldwide. This disease is caused by Lawsonia intracellularis, an intracellular bacterial pathogen that primarily colonizes the ileum. In this study, we evaluated changes to the microbiome of the ileal mucosa, ileal digesta, cecal digesta, and feces subsequent to challenge with L. intracellularis and to an oral live vaccine against L. intracellularis. Given that gut homogenates have been used since 1931 to study this disease, we also characterized the microbial composition of a gut homogenate from swine infected with L. intracellularis that was used as challenge material. The L. intracellularis challenge led to a dysbiosis of the microbiome of both the small and large intestine marked by an increase of pathobionts including Collinsella, Campylobacter, Chlamydia, and Fusobacterium. This microbiome response could play a role in favoring L. intracellularis colonization and disease as well as potentially predisposing to other diseases. Vaccination altered both small and large intestine microbiome community structure and led to a significant 3.03 log10 reduction in the amount of L. intracellularis shed by the challenged pigs. Vaccination also led to a significant decrease in the abundance of Collinsella, Fusobacterium, and Campylobacter among other microbial changes compared with non-vaccinated and challenged animals. These results indicate that L. intracellularis infection is associated with broad changes to microbiome composition in both the large and small intestine, many of which can be mitigated by vaccination.


2021 ◽  
Vol 42 (5) ◽  
pp. 2867-2876
Author(s):  
Tatiane Caleffo ◽  
◽  
Vinicius Dahm ◽  
Jéssica Gonçalves dos Santos ◽  
Arthur Colombari Cheng ◽  
...  

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.


2021 ◽  
Vol 237 ◽  
pp. 110256
Author(s):  
Kezia R. Fourie ◽  
Pooja Choudhary ◽  
Siew Hon Ng ◽  
Milan Obradovic ◽  
Robert Brownlie ◽  
...  

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Emma T. Helm ◽  
Eric R. Burrough ◽  
Fernando L. Leite ◽  
Nicholas K. Gabler

AbstractLawsonia intracellularis is endemic to swine herds worldwide, however much is still unknown regarding its impact on intestinal function. Thus, this study aimed to characterize the impact of L. intracellularis on digestive function, and how vaccination mitigates these impacts. Thirty-six L. intracellularis negative barrows were assigned to treatment groups (n  =  12/trt): (1) nonvaccinated, L. intracellularis negative (NC); (2) nonvaccinated, L intracellularis challenged (PC); and (3) L. intracellularis challenged, vaccinated (Enterisol® Ileitis, Boehringer Ingelheim) 7 weeks pre-challenge (VAC). On days post-inoculation (dpi) 0 PC and VAC pigs were inoculated with L. intracellularis. From dpi 19–21 fecal samples were collected for apparent total tract digestibility (ATTD) and at dpi 21, pigs were euthanized for sample collection. Post-inoculation, ADG was reduced in PC pigs compared with NC (41%, P  <  0.001) and VAC (25%, P  <  0.001) pigs. Ileal gross lesion severity was greater in PC pigs compared with NC (P  =  0.003) and VAC (P  =  0.018) pigs. Dry matter, organic matter, nitrogen, and energy ATTD were reduced in PC pigs compared with NC pigs (P  ≤  0.001 for all). RNAscope in situ hybridization revealed abolition of sucrase-isomaltase transcript in the ileum of PC pigs compared with NC and VAC pigs (P  <  0.01). Conversely, abundance of stem cell signaling markers Wnt3, Hes1, and p27Kip1 were increased in PC pigs compared with NC pigs (P  ≤  0.085). Taken together, these data demonstrate that reduced digestibility during L. intracellularis challenge is partially driven by abolition of digestive machinery in lesioned tissue. Further, vaccination mitigated several of these effects, likely from lower bacterial burden and reduced disease severity.


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