Enterocolitis in cattle associated with Yersinia pseudotuberculosis infection

Genomic Epidemiology and Phenotyping Reveal on-Farm Persistence and Cold Adaptation of Raw Milk Outbreak-Associated Yersinia pseudotuberculosis

Packaged raw milk contaminated with Yersinia pseudotuberculosis mediated a large yersiniosis outbreak in southern Finland in 2014. The outbreak was traced back to a single dairy farm in southern Finland. Here we explore risk factors leading to the outbreak through epidemiologic investigation of the outbreak farm and through genomic and phenotypic characterization of the farm’s outbreak and non-outbreak associated Y. pseudotuberculosis strains. We show that the outbreak strain persisted on the farm throughout the 7-month study, whereas the non-outbreak strains occurred sporadically. Phylogenomic analysis illustrated that the outbreak strain was related to previously published genomes of wild animal isolates from Finland, implying that wild animals were a potential source of the outbreak strain to the farm. We observed allelic differences between the farm’s outbreak and non-outbreak strains in several genes associated with virulence, stress response and biofilm formation, and found that the outbreak strain formed biofilm in vitro and maintained better growth fitness during cold stress than the non-outbreak strains. Finally, we demonstrate the rapid growth of the outbreak strain in packaged raw milk during refrigerated storage. This study provides insight of the risk factors leading to the Y. pseudotuberculosis outbreak, highlights the importance of pest control to avoid the spread of pathogens from wild to domestic animals, and demonstrates that the cold chain is insufficient as the sole risk management strategy to control Y. pseudotuberculosis risk associated with raw drinking milk.

Characterization of the protective immune response to Yersinia pseudotuberculosis infection in mice vaccinated with an LcrV-secreting strain of Lactococcus lactis

BACKGROUND

Pseudotuberculosis is an infection caused by the bacterial enteropathogen Yersinia pseudotuberculosis and is considered to be a significant problem in veterinary medicine. We previously found that intranasal administration of a recombinant Lactococcus lactis strain that secretes the low-calcium response V (LcrV) antigen from Y. pseudotuberculosis (Ll-LcrV) confers protection against a lethal Y. pseudotuberculosis infection. Here, we aimed at characterizing the immunological basis of this LcrV-elicited protective response and at determining the duration of vaccine-induced immunity.

METHODS

Splenocytes from BALB/c mice intranasally immunized with Ll-LcrV or Ll as control were immunostained then analyzed by flow cytometry. Protection against a lethal intravenous injection of Y. pseudotuberculosis was also determined (i) in immunized BALB/c mice depleted or not of CD4⁺, CD8⁺ or CD25⁺ cells and (ii) in naïve BALB/c mice receiving serum from immunized mice by counting the number of bacteria in liver and spleen. Lastly, survival rate of immunized BALB/c mice following a lethal intravenous injection of Y. pseudotuberculosis was followed up to 9-months.

RESULTS

We found that T and B lymphocytes but not non-conventional lymphoid cells were affected by Ll-LcrV immunization. We also observed that depletion of CD4⁺ and CD25⁺ but not CD8⁺ cells in immunized mice eradicated protection against a lethal systemic Y. pseudotuberculosis infection, suggesting that activated CD4⁺ T lymphocytes are required for vaccine-induced protection. Adoptive transfer of LcrV-specific antibodies from Ll-LcrV-immunized animals significantly reduced the bacterial counts in the liver compared to non-vaccinated mice. Lastly, the protective immunity conferred by Ll-LcrV decreased slightly over time; nevertheless almost 60% of the mice survived a lethal bacterial challenge at 9months post-vaccination.

CONCLUSION

Mucosal vaccination of mice with Ll-LcrV induced cell- and antibody-mediated protective immunity against Y. pseudotuberculosis infection in the mouse and the protection is long-lasting.

Proposed reclassification of Pasteurella lymphangitidis Sneath & Stevens 1990 as Yersinia pseudotuberculosis

The 16S rRNA gene sequences of Pasteurella lymphangitidis , Yersinia pseudotuberculosis and Yersinia pestis were found to be identical and multilocus sequence analysis could not discriminate between the three species. The susceptibility to a Y. pseudotuberculosis phage and the presence of the Y. pseudotuberculosis -specific invasin gene in P. lymphangitidis indicate that the latter should be reclassified as Y. pseudotuberculosis .

Yersinia pseudotuberculosis infection in a suckler calf in the United Kingdom: a case report

Enterocolitis caused by Yersinia pseudotuberculosis was identified by bacterial culture and histopathology in a 5-month old suckler calf. No other significant enteric pathogens were detected. Diagnosis of this condition can be missed if selective media are not used for bacteriology and if histopathology is not attempted or the alimentary tract is unsuitable for examination. This is the first case report of Y. pseudotuberculosis infection in a calf in the United Kingdom.

A cohort study of Yersinia infection in goats

OBJECTIVE

To determine the temporal pattern of Yersinia infections in three goat flocks and examine the influence of management and seasonal factors on the incidence of those infections over a 1-year period.

METHODS

A longitudinal study involving monthly culture of faeces for Yersinia spp. from age groups of randomly selected goats on three farms in the Manawatu region of New Zealand.

RESULTS

The incidence of excretion of potentially pathogenic Yersinia (Yersinia pseudotuberculosis and Y enterocolitica biotypes 2, 3 and 5) peaked in winter and fell in summer. In contrast, environmental Yersinia (Y enterocolitica biotype 1A, Y frederiksenii, Y intermedia and Y rohdei) showed no clear pattern of seasonal variation. Pathogenic Yersinia were more prevalent in young animals than in adults, while environmental Yersinia were more prevalent in adults. The same type was isolated from the same animal in two or more successive months in about 20 to 25% of cases, and in the remaining cases there was a gap of at least one month between successive isolations, with many animals yielding a particular type on only a single occasion. A notable difference was that with the potentially pathogenic types, no animal had more than one period of time when it was found to be excreting a particular type, suggesting that immunity develops following exposure. In contrast, it was common for environmental types to be isolated from the same animal throughout the study period. Two goats were suspected to have developed clinical yersiniosis but all remaining infected animals showed no clinical signs of infection.

CONCLUSIONS

Asymptomatic Yersinia carriage was common in goats in New Zealand, with a clear seasonal and age group pattern of infection with potentially pathogenic types. There was evidence that immunity developed to potentially pathogenic types. This is the first time that Y rohdei has been isolated from goats.

Caprine Enteritis Associated with Yersinia pseudotuberculosis Infection

Yersiniosis was prevalent among a caprine herd during the late autumn of 2003 in Iwate Prefecture, Japan. The disease affected 29 of about 100 lactating goats, but not dried or nonparous goats, mature male goats or kids. Four animals died within an epidemic period of 20 days. Affected animals developed decreased milk production with subsequent watery diarrhea, neutrophilia with increased band forms and multiple microabscesses characteristic of yersiniosis in the intestinal mucosa from the jejunum to caecum as well as in the mesenteric lymph nodes. Y. pseudotuberculosis serotype III was isolated from intestinal contents and mesenteric lymph nodes. The organism was also cultured from clinically normal dried animals. The outbreak might have been precipitated by multiple stress factors, such as lactation, cold weather, Corynebacterium pseudotuberculosis infection resulting in abscess formation and tapeworm and coccidium parasitisms.

Enteritis associated with Yersinia pseudotuberculosis infection in a buffalo

A week after transport a 4 month old buffalo calf developed diarrhoea. Its condition gradually deteriorated and it died. Necropsy revealed acute haemorrhagic enteritis and enlarged mesenteric lymph nodes. Haemorrhages and numerous microabscesses were detected in the lamina propria of the small intestine associated with colonies of Gram negative bacteria. Yersinia pseudotuberculosis was isolated from the small intestine and from mesenteric lymph node. Enteritis caused by Y pseudotuberculosis does not appear to have been reported previously in buffalo in Australia.

Experimental infection with Yersinia pseudotuberculosis of ground squirrels (Citellus citellus)

An experimental infection was induced in the European ground squirrel (Citellus citellus) by intraperitoneally injecting of 1 ml. of microbial suspension, containing 1 x 10(9) CFU (colony forming units) of Yersinia pseudotuberculosis, serotypes I and III. The infectious process was dynamically followed up from the 1st up to the 30th day, respectively. Account was rendered to the general condition, the internal body temperature and the mortality rate. The phagocytic activity of alveolar macrophages (aMa) and polymorphonuclear leucocytes (PMNL), isolated from the experimental animals, was also determined, as well as the degree of bacterial dissemination into the viscera and the histomorphological changes that found in the parenchymal organs. These investigations confirm the fact that the bacterial agent has a broad spectrum of alterations in the organism of the host--the European ground squirrel (Citellus citellus) in which the pseudotuberculosis develops as a generalized infection, especially pronounced in the animals that were infected with the serotype III.

Yersinia species isolated from sheep with enterocolitis

In 40 submissions to the Regional Veterinary Laboratory (RVL) Wagga Wagga from sheep in southern New South Wales from 1981 to 1989, 53 isolates of Yersinia sp were recovered from 45 sheep in 37 flocks. Of 53 isolates, 26 were identified as Y. pseudotuberculosis, 20 as Y. enterocolitica, 5 as Y. intermedia and 2 as Y. frederiksenii. Twelve isolates of Y. pseudotuberculosis tested in the slide agglutination test all belonged to serotype III. The 20 Y. enterocolitica isolates were categorised biochemically as biotype 5 strains and, of 6 isolates serotyped, all belonged to serogroup 2,3. Outbreaks of yersiniosis were most common in late winter and early spring and affected flocks often had experienced a change in husbandry. Infection with Yersinia sp was associated with diarrhoea, illthrift and mortality. At necropsy, congestion and occasionally thickening of the intestinal mucosa were observed in affected sheep. Gastrointestinal nematodiasis and coccidiosis often were concurrent findings. The characteristic histological lesion in sheep infected with Y. pseudotuberculosis was acute segmental suppurative erosive enterocolitis. There were no lesions consistently associated with Y. enterocolitica, Y. intermedia or Y. frederiksenii.

Yersiniosis in farmed deer

Samples from 77 chital (Axis axis), 42 fallow (Dama dama), 26 red (Cervus elaphus), 7 rusa (Cervus timorensis) and 1 sambar deer (Cervus unicolor) were examined. Yersinia pseudotuberculosis infection was diagnosed as the cause of death in 6 (23%) of the red and 23 (30%) of the chital deer. Yersiniosis was the most common infectious cause of death diagnosed. Affected deer were usually found moribund or dead, often with faecal staining of the perineum. Gross pathology in chital included a fibrinous enterocolitis, enlarged congested mesenteric lymph nodes and multiple pale foci through the liver. Gross changes in red deer were limited to intense congestion of the intestinal mucosa and enlargement and congestion of mesenteric lymph nodes. Microscopic intestinal changes in both species consisted of microabscessation or diffuse suppurative inflammation of the intestinal mucosa with numerous bacterial colonies in the lamina propria. Multifocal suppurative mesenteric lymphadenitis was a common finding. Multifocal suppurative or non-suppurative hepatitis was frequently present in the liver of chital but was uncommon in the red deer. Yersiniosis occurred during the cooler months from June to November, with younger age classes most commonly affected. Y. pseudotuberculosis serotypes I, II and III were isolated in the ratio 17:3:0 in the chital deer and 1:1:2 in red deer. The clinical, epidemiological and bacteriological features are similar to those documented previously by New Zealand workers. The increased susceptibility to disease of red deer and chital compared to fallow deer and perhaps other species has not previously been documented.

Yersinia pseudotuberculosis enteritis in four calves

A Yersinia pseudotuberculosis enteritis in four yearling calves is described. This is the first report of this organism causing enteric disease in domestic cattle in North America.

Future challenges of disease in the beef cattle industry

Disease control must be part of the management system in any beef cattle enterprise where improved net returns are a constant goal. A current view of the importance of disease is reflected in the research portfolio of the Australian Meat and Live-stock Research and Development Corporation (AMLRDC), where only 14% of projects relate to cattle health problems. Our relative freedom from epidemics is partly responsible for this balance, but the profession should continue to be alert to the range of actual or potential threats to the national herds and those predisposing factors, both managerial and environmental, that influence their effects. In Australia with its crucial beef export component, several priority areas can be identified. They are (i) completion of the Brucellosis and Tuberculosis Eradication Campaign (BTEC) (ii) improved knowledge of the effects of production of subclinical disease including deficiency states (iii) better understanding of the infertility complex from conception to birth. Congenital viral infections such as mucosal disease and the arbovirus group are slowly emerging from their epidemiological obscurity (iv) constant awareness of the potential threat of exotic diseases and defensive methods available to meet them. There is a particular need to understand the epidemiology of the large tropical cattle herd, which interfaces with South-East Asia. Our comparative freedom from epidemics should not cause any relaxation of vigilance by the veterinary services in the private or public sectors. Nor should government be allowed to minimise the critical role of the veterinary profession in our defense against animal disease (v) increased liaison with our trading partners in livestock exports.(ABSTRACT TRUNCATED AT 250 WORDS)

Enteritis in cattle due to Yersinia pseudotuberculosis infection

A selective medium was used to isolate Yersinia sp from the intestinal tract of 222 scouring cattle in Gippsland during 1985 and 1986. Intestinal infection with Y. pseudotuberculosis, particularly of serotype III, was found to be especially prevalent in weaned calves, yearlings and young adult cattle. Clinically affected cattle had a profuse liquid diarrhoea and many were systemically ill. Haematological changes suggestive of infection were present in 38 of 49 of these cattle. At least 35 cattle died and characteristic microabscesses were demonstrated in the intestinal mucosa of 20 of 26 examined histologically. Y. pseudotuberculosis was sensitive to tetracyclines in vitro and this drug produced a rapid bacteriological cure. Yersiniosis occurred during the winter, spring and early summer. Challenge of adult cattle with Y. pseudotuberculosis serotype III did not result in intestinal colonisation or clinical disease. Intestinal infection was, however, established in 4 weaned calves and haematological changes and antibody production were demonstrated in them. Intestinal microabscesses were seen in three calves killed on days 8, 14 and 18 after challenge. The fourth calf eliminated infection by day 18 and no lesions were demonstrated when it was killed on day 72. There is a very high prevalence of antibodies reacting with Y. pseudotuberculosis serotype III in adult cattle. It is concluded that cattle are a common host for this bacterium, infection being frequent, with clinical and fatal disease occurring occasionally. The factors leading to clinical disease are unknown.