Enhancement of enteropathogenic Escherichia coli pathogenicity in young turkeys by concurrent turkey coronavirus infection

Enteropathogenic Escherichia coli modulates the virulence and pathogenicity of Entamoeba dispar

Amoebiasis is a disease caused by Entamoeba histolytica, affecting the large intestine of humans and occasionally leading to extra-intestinal lesions. Entamoeba dispar is another amoeba species considered commensal, although it has been identified in patients presenting with dysenteric and nondysenteric colitis, as well as amoebic liver abscess. Amoebic virulence factors are essential for the invasion and development of lesions. There is evidence showing that the association of enterobacteria with trophozoites contributes to increased gene expression of amoebic virulence factors. Enteropathogenic Escherichia coli is an important bacterium causing diarrhea, with high incidence rates in the world population, allowing it to interact with Entamoeba sp. in the same host. In this context, this study aims to evaluate the influence of enteropathogenic Escherichia coli on ACFN and ADO Entamoeba dispar strains by quantifying the gene expression of virulence factors, including galactose/N-acetyl-D-galactosamine-binding lectin, cysteine proteinase 2, and amoebapores A and C. Additionally, the study assesses the progression and morphological aspect of amoebic liver abscess and the profile of inflammatory cells. Our results demonstrated that the interaction between EPEC and ACFN Entamoeba dispar strains was able to increase the gene expression of virulence factors, as well as the lesion area and the activity of the inflammatory infiltrate. However, the association with the ADO strain did not influence the gene expression of virulence factors. Together, our findings indicate that the interaction between EPEC, ACFN, and ADO Entamoeba dispar strains resulted in differences in vitro and in vivo gene expression of Gal/GalNAc-binding lectin and CP2, in enzymatic activities of MPO, NAG, and EPO, and consequently, in the ability to cause lesions.

First isolation of atypical enteropathogenic Escherichia coli from geese (Anser anser domestica) and first description of atypical EPEC from turkeys and pigeons in Hungary

Background

Escherichia coli is a bacterial species widely distributed among mammals and avian species, and also a member of the normal intestinal microbiota. However, some E. coli strains of different pathotypes can cause disease in both humans and animals. Atypical enteropathogenic E. coli (aEPEC) can infect both animals and humans or influence the severity of other ongoing infections.

Results

In the present study, a total of 332 samples were collected from ducks, geese, turkeys, chickens, and pigeons from the Hungarian Veterinary Diagnostic Directorate, two slaughterhouses, two pigeon keepers and one backyard chicken farm. E. coli was isolated and verified from 319 samples. The isolates were screened by PCR for diarrheagenic E. coli pathotypes. Altogether seven atypical enteropathogenic E. coli (aEPEC) strains were identified: two from four-week-old dead turkeys, two from force-fed geese, and three from pigeons. No further pathotypes were identified in the collection. The atypical EPEC strains were classified phylogenetically to B1, B2, and F, and four out of the seven aEPEC isolates proved to be multidrug resistant. Serotypes of aEPEC strains were uniform collected from same farms and showed diversity between their origins with O76, O145, O109 serogroups.

Conclusions

This is the first report in the literature about aEPEC in goose (Anser anser domestica). Furthermore, this is the first isolation of aEPEC from turkeys and pigeons in Hungary. The uneven distribution of aEPEC in different age groups of poultry suggests that aEPEC disappears with growing up, but stress (e.g.: force-feeding) and concurrent diseases might promote its reappearance in the intestine.

Enteric coronavirus infection in adult horses

A new enteric virus of adult horses, equine coronavirus (ECoV), has recently been recognized. It is associated with fever, lethargy, anorexia, and less frequently, colic and diarrhea. This enteric virus is transmitted via the feco-oral route and horses become infected by ingesting fecally contaminated feed and water. Various outbreaks have been reported since 2010 from Japan, Europe and the USA. While the clinical signs are fairly non-specific, lymphopenia and neutropenia are often seen. Specific diagnosis is made by the detection of ECoV in feces by either quantitative real-time PCR, electron microscopy or antigen-capture ELISA. Supportive treatment is usually required, as most infections are self-limiting. However, rare complications, such as endotoxemia, septicemia and hyperammonemia-associated encephalopathy, have been reported, and have been related to the loss of barrier function at the intestinal mucosa. This review article will focus on the latest information pertaining to the virus, epidemiology, clinical signs, diagnosis, pathology, treatment and prevention of ECoV infection in adult horses.

Equine coronavirus: An emerging enteric virus of adult horses

Equine coronavirus (ECoV) is an emerging virus associated clinically and epidemiologically with fever, depression, anorexia and less frequently colic and diarrhoea in adult horses. Sporadic cases and outbreaks have been reported with increased frequency since 2010 from Japan, the USA and more recently from Europe. A faeco‐oral transmission route is suspected and clinical or asymptomatic infected horses appear to be responsible for direct and indirect transmission of ECoV. A presumptive clinical diagnosis of ECoV infection may be suggested by clinical presentation, haematological abnormalities such as leucopenia due to lymphopenia and/or neutropenia. Confirmation of ECoV infection is provided by specific ECoV nucleic acid detection in faeces by quantitative PCR (qPCR) or demonstration of coronavirus antigen by immunohistochemistry or electron microscopy in intestinal biopsy material obtained ante or post mortem. The disease is generally self‐limiting and horses typically recover with symptomatic supportive care. Complications associated with disruption of the gastrointestinal barrier have been reported in some infected horses and include endotoxaemia, septicaemia and hyperammonaemia‐associated encephalopathy. Although specific immunoprophylactic measures have been shown to be effective in disease prevention for closely‐related coronaviruses such as bovine coronavirus (BCoV), such strategies have yet not been investigated for horses and disease prevention is limited to basic biosecurity protocols. This article reviews current knowledge concerning the aetiology, epidemiology, clinical signs, diagnosis, pathology, treatment and prevention of ECoV infection in adult horses.

Common and emerging infectious diseases in the animal shelter

The beneficial role that animal shelters play is unquestionable. An estimated 3 to 4 million animals are cared for or placed in homes each year, and most shelters promote public health and support responsible pet ownership. It is, nonetheless, inevitable that shelters are prime examples of anthropogenic biological instability: even well-run shelters often house transient, displaced, and mixed populations of animals. Many of these animals have received minimal to no prior health care, and some have a history of scavenging or predation to survive. Overcrowding and poor shelter conditions further magnify these inherent risks to create individual, intraspecies, and interspecies stress and provide an environment conducive to exposure to numerous potentially collaborative pathogens. All of these factors can contribute to the evolution and emergence of new pathogens or to alterations in virulence of endemic pathogens. While it is not possible to effectively anticipate the timing or the pathogen type in emergence events, their sites of origin are less enigmatic, and pathologists and diagnosticians who work with sheltered animal populations have recognized several such events in the past decade. This article first considers the contribution of the shelter environment to canine and feline disease. This is followed by summaries of recent research on the pathogenesis of common shelter pathogens, as well as research that has led to the discovery of novel or emerging diseases and the methods that are used for their diagnosis and discovery. For the infectious agents that commonly affect sheltered dogs and cats, including canine distemper virus, canine influenza virus, Streptococcus spp, parvoviruses, feline herpesvirus, feline caliciviruses, and feline infectious peritonitis virus, we present familiar as well as newly recognized lesions associated with infection. Preliminary studies on recently discovered viruses like canine circovirus, canine bocavirus, and feline norovirus indicate that these pathogens can cause or contribute to canine and feline disease.

Infectious agents associated with diarrhoea in neonatal foals in central Kentucky: a comprehensive molecular study

Reasons for performing study

Diarrhoea caused by infectious agents is common in foals but there is no comprehensive molecular work‐up of the relative prevalence of common agents and appearance of coinfections.

Objectives

To determine the prevalence of 9 infectious agents in gastrointestinal (GI)‐diseased and healthy foals with ages ranging from 1 to 20 weeks of age and to what degree coinfections are associated with clinical signs of GI disease.

Study design

Retrospective controlled observational study.

Methods

The population consisted of 88 Thoroughbred foals aged 2 days to 17 weeks born on 32 different studfarms in Kentucky. Healthy (n = 37) and GI‐diseased (n = 51) foals were identified based on clinical presentation. Faecal samples were analysed for 9 infectious agents by real‐time PCR: equine rotavirus, equine coronavirus, Clostridium difficile toxins A & B, Neorickettsia risticii, Clostridium perfringens alpha toxin, Lawsonia intracellularis, Rhodococcus equi, Cryptosporidium spp., and Salmonella spp. Salmonella was also cultured from overnight selenite enrichment broth.

Results

The prevalence of infectious pathogens under study was between 0% (Lawsonia intracellularis) and 34.6% (equine rotavirus). The overall prevalence for any infectious agent was 63.2% in the GI‐diseased group and 43.2% in the healthy group. Coinfections were significantly more frequent in the sick group (15 monoinfections vs. 22 coinfections) than in the healthy group (12 vs. 4, respectively, P = 0.0002). Six of the 8 infectious agents were associated with the GI‐diseased group, the other 2 were not (equine coronavirus and R. equi).

Conclusions

The use of panels rather than individual tests in combination with quantitative toxin gene analysis enables detection of coinfections significantly associated with risk of disease. Several infectious diseases previously not tested for or considered unimportant were found at high prevalence and require further investigation.