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Journal ArticleDOI

Pathogenic Yersinia enterocolitica O:3 isolated from a hunted wild alpine ibex.

01 Mar 2013-Epidemiology and Infection (Cambridge University Press)-Vol. 141, Iss: 3, pp 612-617
TL;DR: Interestingly, one Y. enterocolitica O:3 strain, isolated from an alpine ibex, carried the important virulence genes located on the virulence plasmid (yadA and virF) and in the chromosome (ail, hreP, myfA and ystA).
Abstract: Occurrence of Yersinia spp. in wild ruminants was studied and the strains were characterized to get more information on the epidemiology of enteropathogenic Yersinia in the wildlife. In total, faecal samples of 77 red deer, 60 chamois, 55 roe deer and 27 alpine ibex were collected during 3 months of the hunting season in 2011. The most frequently identified species was Y. enterocolitica found in 13%, 10%, 4% and 2% of roe deer, red deer, alpine ibex and chamois, respectively. Interestingly, one Y. enterocolitica O:3 strain, isolated from an alpine ibex, carried the important virulence genes located on the virulence plasmid (yadA and virF) and in the chromosome (ail, hreP, myfA and ystA). Most of the Y. enterocolitica strains belonged to biotype 1A of which 14 were ystB positive. Further studies are needed to clarify the importance of alpine ibex as a reservoir of pathogenic Y. enterocolitica.

Summary (1 min read)

INTRODUCTION

  • In a Y. pseudotuberculosis outbreak in Finland, it was likely that iceberg lettuce were contaminated by irrigation water contaminated with roe deer faeces [3].
  • The prevalence of Y. enterocolitica and Y. pseudotuberculosis in wild deer, however, has so far been very rarely studied [9–12].
  • In these few studies, both species were isolated from faecal samples of animals free from obvious symptoms of disease.
  • All Y. enterocolitica strains were considered nonpathogenic, and Y. pseudotuberculosis was very rarely isolated from faecal samples.

Animals

  • This study was based on investigations carried out during 3 months (September–November) of the hunting season in 2011.
  • The faecal samples originated from 77 red deer, 60 chamois, 55 roe deer and 27 alpine ibex.
  • After opening the large intestine, faecal matter (at least 10 g) was collected from the colon, placed into sterile tubes and stored under refrigeration.
  • The CIN plates were incubated at 30 xC for 24–48 h. Presumptive positive colonies were subcultured on blood agar and then tested for the urease enzyme.
  • One isolate per sample in a total of 20 strains were biotyped and serotyped.

Further strain characterization

  • Eight genes were studied by PCR: two virulence genes (yadA, virF) located on the virulence plasmid of the pathogenic Yersinia spp. (pYV) and five virulence genes (ail, ystA, ystB, myfA, hreP) and rfbC for O:3 serotype located in the chromosome [17–20].
  • The fluorescence intensity of SYBR Green and the melting curve analysis were studied using the CFX96 system .
  • A threshold cycle (Ct) under 30 and a specific melting temperature (Tm) indicated a positive result.

Antimicrobial susceptibility testing

  • Antimicrobial resistance analysis was performed by disk-diffusion test according to Clinical and Laboratory Standards Institute (CLSI, 2009).
  • The reference strain Escherichia coli ATCC 25922 was used as the quality control.

RESUTS AND DISCUSSION

  • The majority of the Y. enterocolitica strains isolated from food and the environment belong to this biotype and these strains are generally regarded as non-pathogenic because the prerequisite virulence genes are missing [6, 23].
  • One Y. enterocolitica strain (strain no. 17) that harboured all the important virulence genes was isolated from faeces of a clinically healthy wild alpine ibex (Capra ibex) (Table 3).

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Year:2013
PathogenicYersiniaenterocoliticaO:3isolatedfromahuntedwildalpine
ibex
Joutsen,S;Sarno,E;Fredriksson-Ahomaa,M;Cernela,N;Stephan,Roger
Abstract:OccurrenceofYersiniaspp.inwildruminantswasstudiedandthestrainswerecharacterized
togetmoreinformationontheepidemiologyofenteropathogenicYersiniainthewildlife.Intotal,faecal
samplesof77reddeer,60chamois,55roedeerand27alpineibexwerecollectedduring3monthsofthe
huntingseasonin2011.ThemostfrequentlyidentiedspecieswasY.enterocoliticafoundin13%,10%,
4%and2%ofroedeer,reddeer,alpineibexandchamois,respectively.Interestingly,oneY.enterocolitica
O:3strain,isolatedfromanalpineibex,carriedtheimportantvirulencegeneslocatedonthevirulence
plasmid(yadAandvirF)andinthechromosome(ail,hreP,myfAandystA).MostoftheY.enterocolitica
strainsbelongedtobiotype1Aofwhich14wereystBpositive.Furtherstudiesareneededtoclarifythe
importanceofalpineibexasareservoirofpathogenicY.enterocolitica.
DOI:https://doi.org/10.1017/S0950268812001239
PostedattheZurichOpenRepositoryandArchive,UniversityofZurich
ZORAURL:https://doi.org/10.5167/uzh-81834
JournalArticle
PublishedVersion
Originallypublishedat:
Joutsen,S;Sarno,E;Fredriksson-Ahomaa,M;Cernela,N;Stephan,Roger(2013).PathogenicYersinia
enterocoliticaO:3isolatedfromahuntedwildalpineibex.EpidemiologyandInfection,141(03):612-617.
DOI:https://doi.org/10.1017/S0950268812001239

Pathogenic Yersinia enterocolitica O:3 isolated from a hunted
wild alpine ibex
S. JOU TSE N
1
, E. SARNO
2
,
3
, M. FREDRIKSSON-AHOMAA
1
, N. CERNELA
3
AND R. STEPHAN
3
*
1
Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of
Helsinki, Finland
2
Department of Zootechnical Science and Food Inspection, Faculty of Veterinary Medicine, University of Naples
Federico II, Naples, Italy
3
Institute for Food Safety and Hygiene, Vetsuisse Faculty University of Zurich, Zurich, Switzerland
Received 20 March 2012; Final revision 4 May 2012; Accepted 23 May 2012;
first published online 15 June 2012
SUMMARY
Occurrence of Yersinia spp. in wild ruminants was studied and the strains were characterized to
get more information on the epidemiology of enteropathogenic Yersinia in the wildlife. In total,
faecal samples of 77 red deer, 60 chamoi s, 55 roe deer and 27 alpine ibex were collected
during 3 months of the hunting season in 2011. The most frequently identified species was
Y. enterocolitica found in 13%, 10%, 4% and 2 % of roe deer, red deer, alpine ibex and chamois,
respectively. Interestingly, one Y. enterocolitica O:3 strain, isolated from an alpine ibex, carried
the important virulence genes located on the virulence plasmid (yadA and virF) and in the
chromosome (ail, hreP, myfA and ystA). Most of the Y. enterocolitica strains belonged to
biotype 1A of which 14 were ystB positive. Further studies are needed to clarify the importance
of alpine ibex as a reservoir of pathogenic Y. enterocolitica.
Key words: Characterization, hunted wild ruminants, Yersinia enterocolitica.
INTRODUCTION
Yersiniosis is an important zoonotic disease in hu-
mans in Europe [1]. Most of the reported cases are
caused by Y. enterocolitica. Human enteric yersiniosis
is thought to be primarily foodborne [2]. Y. entero-
colitica has been shown to be transmitted mainly by
pork products and Y. pseudotuberculosis by contam-
inated fresh produce. In a Y. pseudotuberculosis out-
break in Finland, it was likely that iceberg lettuce
were contaminated by irrigation water contaminated
with roe deer faeces [3]. In a small study conducted in
Germany, raw game (including meat from roe deer,
red deer, and chamois) were frequently (38%) con-
taminated with potentially pathogenic (ail -positive)
Y. enterocolitica when studied by polymerase chain
reaction (PCR) [4].
Wild boars were recently shown to be an important
reservoir of enteropathogenic Y. enterocolitica and
Y. pseudotuberculosis in Switzerland [5]. Yersiniosis
due to Y. pseudotuberculosis has also been shown
to be a disease of major importance in deer [6, 7].
Moreover, Y. pseudot uberculosis has also been re-
ported to be a common finding in clinically healthy
farmed deer weaners in New Zealand [8].
* Author for correspondence: Professor R. Stephan, Institute for
Food Safety and Hygiene, Vetsuisse Faculty University of Zurich,
Winterthurerstr. 272, CH-8057 Zurich, Switzerland.
(Email : stephanr@fsafety.uzh.ch)
Epidemiol. Infect. (2013), 141, 612–617. f Cambridge University Press 2012
doi:10.1017/S0950268812001239

The prevalence of Y. enterocolitica and Y. pseudo-
tuberculosis in wild deer, however, has so far been
very rarel y studied [9–12]. In these few studies, both
species were isolated from faecal samples of animals
free from obvious symptoms of disease. However,
all Y. enterocolitica strains were considered non-
pathogenic, and Y. pseudotuberculosis was very rarely
isolated from faecal samples. The aim of this work
was to study the occurrence of Yersinia spp. in
wild ruminants in Swi tzerland and to characterize
the strains in ord er to obtain more information on
the epidemiology of enteropathogenic Yersinia in the
wildlife.
METHODS
Animals
This study was based on investigations carried out
during 3 months (September–November) of the
hunting season in 2011. The samples originated from
shot red deer (Cervus elaphus), roe deer (Capreolus
capreolus), chamois (Rupicapra rupicapra), and ibex
(Capra ibex). The sampled animals were hunted in the
central and eastern part of Switzerland. In total, 219
faecal samples (red deer, roe deer, chamois, ibex) were
examined. The faecal samples originated from 77 red
deer, 60 chamois, 55 roe deer and 27 alpine ibex. State
gamekeepers and hunters collected the samples in
the field immediately after shooting and evisceration
of the wild ruminants. After opening the large intes-
tine, faecal matter (at least 10 g) was collected from
the colon, placed into sterile tubes and stored under
refrigeration. For each hunted animal, sex, age, and
location of hunting were recorded.
Yersinia detection and identification
About 1 g faecal material was mixed in 10 ml PMB
[13, 14]. After 2 weeks of cold enrichment at 4 xC,
10 ml of the enrichment was plated on cefsulodin-
irgasan-novobiosin (CIN) agar (Oxoid AG,
Switzerland). The CIN plates were incubated at 30 xC
for 24–48 h. Presumptive positive colonies were
subcultured on blood agar and then tested for
the urease enzyme. Urease-positive colonies were
identified with API 20E and matrix-assisted laser
desorption/ionization–time of flight (MALDI–TOF)
mass spectrometry [15, 16]. One isolate per sample in
a total of 20 strains were biotyped and serotyped. The
biotype was determined using pyrazinamidase and
Tween activity, esculin hydrolysis, indole production,
and salicin, xylose and trehalose fermentation and
serotyping was performed with slide agglutination
using commercial Y. enterocolitica O :1–O:3, O:5, and
O:9 antisera (Denka Seiken, Japan).
Further strain characterization
Eight genes were studied by PCR : two virulence genes
(yadA, virF) located on the virulence plasmid of the
pathogenic Yersinia spp. (pYV) and five virulence
genes (ail, ystA, ystB, myfA, hreP) and rfbC for O:3
serotype located in the chromosome [17–20].
The DNA was released from bacterial colonies by
heating at 97 xC for 10 min, and 1 ml of this liquid
was added to 19 ml of the mastermix (iQ
TM
SYBR
Green Supermix; Bio-Rad, USA). The fluorescence
intensity of SYBR Green and the melting curve
analysis were studied using the CFX96 system (Bio-
Rad). A threshold cycle (C
t
) under 30 and a specific
melting temperature (T
m
) indicated a positive result.
Antimicrobial susceptibility testing
Antimicrobial resistance analysis was performed
by disk-diffusion test according to Clinical and
Laboratory Standards Institute (CLSI, 2009).
Fourteen antimicrobials were tested: ampicillin
(10 mg), amoxicillin/clavulanic acid (20/10 mg), cefa-
lothin (30 mg), cefoxitin (30 mg), cefpodoxim (10 mg),
ceftazidim (30 mg), cefuroxime (30 mg), ciprofloxacin
(5 mg), gentamicin (10 mg), kanamycin (30 mg), nali-
dixic acid (30 mg), streptomycin (10 mg), tetracycline
(30 mg) and trimethoprim/sulfamethoxazole (1
.
25/
23
.
75 mg) [16]. The reference strain Escherichia coli
ATCC 25922 was used as the quality control.
RESUTS AND DISCUSSION
The occurrence of Yersinia spp. varied between 4%
and 13 % in wild ruminants being highest in roe
(13%) and red deer (12 %) (Table 1). The most fre-
quently identified species was Y. enterocoli tica found
in 13 %, 10%, 4% an d 2% of roe deer, red deer,
alpine ibex and ch amois, respectively. Sur prisingly,
no Y. pseudotuberculosis was isolated even though
cold enrichment in peptone broth supplemented with
1% mannitol and 0
.
15% bile salts (PMB), which
should be favourable for Y. pseudotuberculosis [21],
was used. The prevalence of Y. enterocolitica and
Y. pseudotuberculosis in wild deer has so far very
rarely been studied (Table 2). In Japan, 4 % of the
Y. enterocolitica in hunted wild ruminants 613

deer were shown to shed Y. pseudotuberculosis in
faeces [11]. In Norway, the prevalence of Yersinia in
wild red deer was clearly lower [12]. One reason for
the higher prevalence of Yersinia in our study could
be due to the use of a cold enrichment instead of
2 days enrichment at 21 xC. Y. enterocolitica was also
the dominant species in Norwegian deer ; however,
one Y. pseudotuberculosis strain was detected in
Norway. In Italy and New Zealand, the preval ence
of Yersinia in red deer was clearly higher (Table 2).
In the Italian study, most of the strains isolated were
Y. kristensenii. One reason for the low isolation rate
of Y. kristensenii in our study could be that we used
CIN agar and Y. kristensenii grows very slowly.
Y. enterocolitica was the dominant species in wild red
deer in New Zealand ; however, Y. frederiksenii was
also frequently identified [9]. In the same study,
Y. pseudotuberculosis was sporadically isolated from
clinically healthy farmed deer but not from wild deer.
One reason for the low prevalence of Y. pseudo-
tuberculosis could be that the carriage status cannot
be adequately identified by faecal culture due to either
sporadic shedding of this pathogen or due to the
localization of this pathogen in the mesenteric or
ileocecal lymph nodes [9].
The Yersinia spp. strains were identified with
MALDI–TOF, API 20E and biotyped (Table 3). Only
one of the 20 strains (strain no. 20) could not be
identified at species level by MALDI–TOF. By API
20E this strain was identified as Y. frederiksenii/
intermedia with an ID% of 98
.
5%. The biotype
remained unknown for three Y. enterocolitica
strains (strain nos. 15–17) by MALDI–TOF. One
of the Y. enterocolitica strains (strain no. 17) was
Table 1. Prevalence of Yersinia spp. in faeces of clinically healthy wild
ruminants in Switzerland 2011
Animal species
Animals
studied, n
Yersinia-positive
animals, n (%)
Yersinia spp.
(no. of strains)
Cervus elaphus (red deer) 77 9 (12%) Y. enterocolitica (8)
Y. kristensenii (1)
Rupicapra rupicapra (chamois) 60 3 (5 %) Y. enterocolitica (1)
Y. kristensenii (1)
Yersinia sp. (1)
Capreolus capreolus (roe deer) 55 7 (13%) Y. enterocolitica (7)
Capra ibex (alpine ibex) 27 1 (4%) Y. enterocolitica (1)
All species 219 20 (9%) Y. enterocolitica (17)
Y. kristensenii (2)
Yersinia sp. (1)
Table 2. Prevalence of Yersinia spp. in faeces of clinically healthy wild deer
Country Animal species
Animals
studied, n
Yersinia-positive
animals, n (%)
Identified Yersinia spp.
(no. of strains) Ref.
Italy Red deer 60 14 (23%) Y. kristensenii (13) [10]
Y. enterocolitica (1)
Roe deer 13 1 (8%)
Chamois 7 0
Japan Sika deer 215 8 (4%) Y. pseudotuberculosis (8) [11]
New Zealand Red deer 83 26 (31%) Y. enterocolitica (13) [9]
Y. kristensenii (1)
Y. intermedia (1)
Y. frederiksenii (11)
White-tailed deer 40 3 (8 %) Y. enterocolitica (2)
Y. frederiksenii (1)
Norway Red deer 170 10 (6%) Y. enterocolitica (13) [12]
Y. mollaretii (1)
Y. pseudotuberculosis (1)
614 S. Joutsen and others

regarded as potentially pathogenic because it
was pyrazin amidase, esculin and salicin negative.
However, it was impossible to clearly diff erentiate if
this strain belongs to biotype 3 or 5. This strain was
xylose positive and trehalose negative. A typical strain
of biotype 3 should be xylose and trehalose positive,
and a typical biotype 5 strain should be xylose
and trehalose negative [22]. This strain was also sor-
bitol negative. Y. enterocolitica strains are typically
sorbitol positive and Y. pseudotuberculosis strains
sorbitol negative.
Most (2/17) of the Y. enterocolitica strains from
wild ruminants belonged to biotype 1A. The majority
of the Y. enterocolitica strains isolated from food and
the environment belong to this biotype and these
strains are generally regarded as non-pathogenic
because the prerequisite virulence genes are missing
[6, 23]. Further, in this study, the most important
virulence genes (ail, yadA, virF) are missing in biotype
1A strains (Table 3). All the 14 strains identified as
Y. enterocolitica 1A by MALDI–TOF carried the
ystB gene. Some evidence indicates that YstB plays a
role in the pathogenesis caused by Y. enterocolitica 1A
[23]. Five of the ystB-positive strains also carried
hreP. Two ystB-positive strains were also positive for
myfA. Both hrePandmyfA have sporadically been
identified in ystB-positive Y. enterocolitica 1A strains.
However, the impact of hreP and myf A in virulence
Table 3. Identification and characterisation of the Yersinia strains isolated from wild ruminants free from obvious
symptoms of disease
Strain no. MALDI–TOF MS
API 20E
Bio-type Serotype
Presence of the virulence genes
Profile ID (%)
ail, ystA
yadA, virF ystB
myfA,
hreP
1–6 Y. enterocolitica, 1A 1 155 723 98
.
31A O:5 x+V
7–9 Y. enterocolitica, 1A 1 155 723 98
.
31A O:8 x+V
10–14 Y. enterocolitica, 1A 1 155 723 98
.
31A NT x+V
15–16 Y. enterocolitica, NT 1 155 723 98
.
31A NT xxx
17 Y. enterocolitica, NT 1 114 321 99
.
6 3 or 5 O:(1,2,)3 +x+
18–19 Y. kristensenii 1 114 503 89
.
2NT NT x V x
20 Yersinia sp. 1 155 733 98
.
5* NT NT xxx
MALDI–TOF MS, Matrix-assisted laser desorption/ionization–time of flight mass spectrometry ; NT, biotype not typable ;
V, the genes were detected in some strains.
* ID for Y. frederiksenii/intermedia.
Table 4. Antimicrobial resistance patterns in Yersinia strains isolated from wild game
Antimicrobial agent*
Number of strains
YE 1A (16)# YE 5 (1) YK (2) Y sp. (1)
IRIRIRIR
Ampicillin 0 16 0 1 1 1 0 1
Amoxicillin/clavulanic acid 0 16 1 0 2 0 0 1
Cefalothin 0 16 0 1 0 2 0 1
Cefoxitin 8 6 0 0 0 0 1 0
Cefpodoxim 3 0 1 0 2 0 0 0
Cefuroxime 2 0 1 0 1 0 0 0
Kanamycin 2 0 0 0 0 0 0 0
Streptomycin 2 0 1 0 0 0 0 0
YE, Y. Enterocolitica ; YK, Y. kristensenii; Y sp., Yersinia species ; I, intermediate ; R, resistant.
* only antibiotics where intermediate and resistant strains were found are listed.
# Number of strains studied.
Y. enterocolitica in hunted wild ruminants 615

Citations
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  • ...These pathogens have seldom been found in deer faeces (Joutsen et al., 2013; Gnat et al., 2015; Syczylo et al., 2018) or on deer carcasses in Europe (Paulsen and Winkelmayer, 2004; Obwegeser et al....

    [...]

  • ..., stxharbouring Escherichia coli (STEC), Yersinia enterocolitica/pseudotuberculosis and Listeria monocytogenes, which are among the most common foodborne pathogens causing illness in humans, have sporadically been detected in the faeces of hunted wild ruminants (Joutsen et al., 2013; Díaz-Sánchez et al., 2013; Gnat et al., 2015)....

    [...]

Journal ArticleDOI
TL;DR: The European population of wild boar continues to grow and spread to new areas, therefore, wild boars harbouring potentially pathogenic Y. enterocolitica 4/O:3 strains pose a challenge to public health.
Abstract: The objective of this study was to identify the bioserotypes and virulence markers of Yersinia enterocolitica strains isolated from wild boars in Poland. Bacteriological examination of 302 rectal swabs from 151 wild boars resulted in the isolation of 40 Y. enterocolitica strains. The majority of the examined strains (n = 30), belonged to bioserotype 1A/NI. The presence of individual Y. enterocolitica strains belonging to bioserotypes 1B/NI (3), 1A/O:8 (2), 1A/O:27 (2), 2/NI (1), 2/O:9 (1) and 4/O:3 (1) was also demonstrated. Amplicons corresponding to ail and ystA genes were observed only in one Y. enterocolitica strain – bioserotype 4/O:3. The ail and ystB gene amplicons were noted in 11 Y. enterocolitica biotype 1A strains, although single amplicons of ystB gene were found in 28 of the tested samples. In four out of eight cases when two Y. enterocolitica strains were isolated from the same animal, the strains differed in biotype, serotype or virulence markers. The European population of wild boars continues to grow and spread to new areas, therefore, wild boars harbouring potentially pathogenic Y. enterocolitica 4/O:3 strains pose a challenge to public health.

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  • ...enterocolitica O:3 strain isolated from a hunted wild alpine ibex in 2012 was identified in only one study [11]....

    [...]

Journal ArticleDOI
TL;DR: The Y enterocolitica strains isolated from wild ruminants had the amplicons of the ystB gene, what suggest they can be potential source of Y entericolitica infection for humans.
Abstract: Free-living animals are an important environmental reservoir of pathogens dangerous for other animal species and humans. One of those is Yersinia (Y.) enterocolitica, the causative agent of yersiniosis – foodborne, enzootic disease, significant for public health. The purpose of the study was to identify bioserotypes and virulence markers of Y. enterocolitica strains isolated from roe deer (Capreolus capreolus) and red deer (Cervus elaphus) obtained during the 2010/2011 hunting season in north-eastern Poland. From among 48 rectal swabs obtained from 24 roe deer, two strains of Y. enterocolitica from one animal were isolated. Although both belonged to biotype 1A they were identified as different serotypes. The strain obtained from cold culture (PSB) belonged to serotype O:5, while the strain isolated from warm culture (ITC) was regarded as nonidentified (NI), what may suggest mixed infection in that animal. The presence of ystB gene, coding for YstB enterotoxin, directly related to Y. enterocolitica pathogenicity was detected in both strains using triplex PCR. The effect of the examination of 32 swabs obtained from 16 red deer was the isolation of two Y. enterocolitica strains from two different animals. Both belonged to biotype 1A with NI serotype, but were originated from different types of culture. They gave positive results in case of products of a size corresponding to the ystB gene. No amplicons corresponding to ail and ystA genes were found. Roe deer and red deer may carry and shed Y. enterocolitica, what seems to be important in aspect of an environmental reservoir of this pathogen. The Y. enterocolitica strains isolated from wild ruminants had the amplicons of the ystB gene, what suggest they can be potential source of Y. enterocolitica infection for humans.

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Journal ArticleDOI
TL;DR: The results suggest that wild small mammals, especially voles, may serve as carriers for ail-positive Y. enterocolitica 1A and Y. kristensenii and demonstrate that voles and shrews sporadically excrete pYV- positive Y. pseudotuberculosis 1/O:2, respectively, in their feces and, thus, can serve as a contamination source for vegetables by contaminating the soil.
Abstract: Yersinia enterocolitica and Yersinia pseudotuberculosis are important zoonotic bacteria causing human enteric yersiniosis commonly reported in Europe. All Y. pseudotuberculosis strains are considered pathogenic, while Y. enterocolitica include both pathogenic and nonpathogenic strains which can be divided into six biotypes (1A, 1B, and 2-5) and about 30 serotypes. The most common types causing yersiniosis in Europe are Y. enterocolitica bioserotypes 4/O:3 and 2/O:9. Strains belonging to biotype 1A are considered as nonpathogenic because they are missing important virulence genes like the attachment-invasion-locus (ail) gene in the chromosome and the virulence plasmid. The role of wild small mammals as a reservoir of enteropathogenic Yersinia spp. is still obscure. In this study, the presence of Yersinia spp. was examined from 1840 wild small mammals, including voles, mice, and shrews, trapped in Finland during a 7-year period. We isolated seven Yersinia species. Y. enterocolitica was the most common species, isolated from 8% of the animals; while most of these isolates represented nonpathogenic biotype 1A, human pathogenic bioserotype 2/O:9 was also isolated from a field vole. Y. pseudotuberculosis of bioserotype 1/O:2 was isolated from two shrews. The ail gene, which is typically only found in the isolates of biotypes 1B and 2-5 associated with yersiniosis, was frequently (23%) detected in the nonpathogenic isolates of biotype 1A and sporadically (6%) in Yersinia kristensenii isolates. Our results suggest that wild small mammals, especially voles, may serve as carriers for ail-positive Y. enterocolitica 1A and Y. kristensenii. We also demonstrate that voles and shrews sporadically excrete pYV-positive Y. enterocolitica 2/O:9 and Y. pseudotuberculosis 1/O:2, respectively, in their feces and, thus, can serve as a contamination source for vegetables by contaminating the soil.

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Cites background from "Pathogenic Yersinia enterocolitica ..."

  • ...There are only few studies on the prevalence of Yersinia spp. in wild animals in Europe including wild boars and deer but not wild small mammals (Fredriksson-Ahomaa et al. 2011, Joutsen et al. 2013, Bancerz-Kisiel et al. 2015)....

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  • ...The presence of the virulence plasmid was studied by PCR targeting the virF gene on the virulence plasmid (pYV) (Nakajima et al. 1992, Joutsen et al. 2013)....

    [...]

References
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Journal Article

339 citations


"Pathogenic Yersinia enterocolitica ..." refers background in this paper

  • ...of biotype 3 should be xylose and trehalose positive, and a typical biotype 5 strain should be xylose and trehalose negative [22]....

    [...]

Journal ArticleDOI
TL;DR: Iceberg lettuce was implicated as the vehicle of a widespread foodborne Y. pseudotuberculosis outbreak and Ongoing laboratory-based surveillance and serotype analysis were essential in the rapid detection of infection.
Abstract: Background The vehicles and sources of Yersinia pseudotuberculosis infection are unknown. In Finland, clinical microbiology laboratories routinely report Y. pseudotuberculosis isolations and submit isolates for serotype analysis. In October 1998, the number of serotype O:3 infections increased markedly. Methods Case patients with culture-confirmed Y. pseudotuberculosis O:3 infection were identified by use of laboratory-based surveillance. We conducted a population-based case-control study. Healthy community control subjects were matched by age, sex, and postal code. Isolates were subtyped by pulsed-field gel electrophoresis (PFGE). Results Nationwide, 47 case patients were identified (age range, 2-77 years; median, 19 years). One patient with bacteremia died; 5 underwent appendectomies. We enrolled 38 case patients and 76 control subjects in the case-control study. Seventy-one percent of case patients and 42% of control subjects reported having eaten iceberg lettuce (matched odds ratio, 3.8; 95% confidence interval, 1.3-9.4); a dose-response relationship was found for increasing frequency of consumption. Of the 27 isolates obtained from case patients and tested in the analysis, all had indistinguishable PFGE patterns. Four lunch cafeterias that had served iceberg lettuce were associated with clusters of case patients. The lettuce was traced back to originating farms. Conclusions Iceberg lettuce was implicated as the vehicle of a widespread foodborne Y. pseudotuberculosis outbreak. Ongoing laboratory-based surveillance and serotype analysis were essential in the rapid detection of infection. Cases of yersiniosis, which appear to be sporadic, may be part of unrecognized outbreaks caused by contaminated fresh produce.

170 citations

Journal ArticleDOI
TL;DR: A rapid and specific real-time PCR method for the detection of pathogenic Y. enterocolitica bacteria in food, as presented here, provides a superior alternative to the currently available detection methods and makes it possible to identify the foods at risk for Y. entersocolitICA contamination.
Abstract: The current methods for the detection of pathogenic Yersinia enterocolitica bacteria in food are time consuming and inefficient. Therefore, we have developed and evaluated in-house a TaqMan probe-based real-time PCR method for the detection of this pathogen. The complete method comprises overnight enrichment, DNA extraction, and real-time PCR amplification. Also included in the method is an internal amplification control. The selected primer-probe set was designed to use a 163-bp amplicon from the chromosomally located gene ail (attachment and invasion locus). The selectivity of the PCR method was tested with a diverse range (n = 152) of related and unrelated strains, and no false-negative or false-positive PCR results were obtained. The sensitivity of the PCR amplification was 85 fg purified genomic DNA, equivalent to 10 cells per PCR tube. Following the enrichment of 10 g of various food samples (milk, minced beef, cold-smoked sausage, fish, and carrots), the sensitivity ranged from 0.5 to 55 CFU Y. enterocolitica. Good precision, robustness, and efficiency of the PCR amplification were also established. In addition, the method was tested on naturally contaminated food; in all, 18 out of 125 samples were positive for the ail gene. Since no conventional culture method could be used as a reference method, the PCR products amplified from these samples were positively verified by using conventional PCR and sequencing of the amplicons. A rapid and specific real-time PCR method for the detection of pathogenic Y. enterocolitica bacteria in food, as presented here, provides a superior alternative to the currently available detection methods and makes it possible to identify the foods at risk for Y. enterocolitica contamination.

121 citations

Journal ArticleDOI
TL;DR: This study demonstrates that MALDI-TOF-MS is a reliable and powerful tool for the rapid identification of Y. enterocolitica strains to the species level and allows subtyping of strains toThe biotype level.

107 citations

Journal ArticleDOI
TL;DR: Prevalence of pathogenic Y. enterocolitica in different sources in Bavaria is presented, and the antimicrobial resistance of human and nonhuman strains is reported.
Abstract: Yersinia enterocolitica is the most common species causing enteric yersiniosis, which is still the third most frequently reported foodborne gastroenteritis in Europe. Y. enterocolitica generally causes sporadic human infections, and outbreaks are rare. The most important infection source of yersiniosis is believed to be contaminated pork and pork products. Data on the prevalence of pathogenic Y. enterocolitica in animals and foodstuffs are very limited and old; thus, more information on the extent and range of the prevalence of this enteropathogen in nonhuman sources is needed. In this work, prevalence of pathogenic Y. enterocolitica in different sources in Bavaria is presented. Further, the antimicrobial resistance of human and nonhuman strains is reported. The highest isolation rate of pathogenic Y. enterocolitica (67%) was found in tonsils of slaughter pigs. No pathogenic strains were isolated from cattle, sheep, turkey, and horses. ail-Positive Y. enterocolitica was detected in dogs (5%), cats (3%), and rodents (3%) by real-time PCR. Pathogenic Y. enterocolitica was isolated only from raw pork, especially from edible offal (51%). Surprisingly, 38% of game was contaminated with this pathogen when the samples were studied with PCR. Additionally, some raw pork sausages and one poultry sample were PCR positive. All pathogenic Y. enterocolitica isolates from nonhuman sources were belonging to bioserotype 4/O:3. Antimicrobial resistance of 60 human and 140 porcine strains of bioserotype 4/O:3 was tested by the agar disc diffusion method to 15 different antimicrobial agents. All Y. enterocolitica 4/O:3 strains were susceptible to most of the tested antibacterial agents.

103 citations

Frequently Asked Questions (1)
Q1. What contributions have the authors mentioned in the paper "Pathogenic yersinia enterocolitica o:3 isolated from a hunted wild alpine ibex" ?

Occurrence of Yersinia spp. in wild ruminants was studied and the strains were characterized to get more information on the epidemiology of enteropathogenic Yersinia in the wildlife. Further studies are needed to clarify the importance of alpine ibex as a reservoir of pathogenic Y. enterocolitica.