Molecular detection of bovine kobuviruses in Italy
Barbara Di Martino
Federica Di Proﬁo
Elisabetta Di Felice
Maria Gabriella Pistilli
Received: 18 May 2012 / Accepted: 29 June 2012 / Published online: 11 August 2012
Ó Springer-Verlag 2012
Abstract Faecal samples obtained from either asymp-
tomatic or diarrhoeic calves in Italy were screened for
bovine kobuviruses (BKVs) using speciﬁc primers. BKV
RNA was detected in 4.9 % of the samples, with higher
positivity rates in diarrhoeic calves (5.3 %) than in
asymptomatic animals (4.8 %), although the difference was
not statistically signiﬁcant. Upon sequence analysis, all of
the Italian viruses formed a tight group along with BKV-
like sequences previously detected in Thailand and Japan.
Picornaviruses in the family Picornaviridae are small non-
enveloped viruses with a single-stranded, positive-sense
RNA genome. Based on genotypic and serological charac-
terization, picornaviruses are currently divided into 12 gen-
era: Enterovirus, Aphthovirus, Cardiovirus, Hepatovirus,
Parechovirus, Erbovirus, Teschovirus, Sapelovirus, Sene-
cavirus, Tremovirus, Avihepatovirus, and Kobuvirus .
The genus Kobuvirus includes two ofﬁcially recognized
species, Aichi virus and Bovine kobuvirus [22, 23], and one
porcine kobuvirus (PKV) [16, 17], as a candidate species.
More recently, kobuvirus-like sequences have also been
found in humans, sheep, goats, rodents and dogs [1–3, 5,
10, 15, 19].
Aichi virus (AiV) (strain A846/88) was ﬁrst isolated
from a person with acute gastroenteritis in 1989 in Japan
. Since then, AiVs have been detected in gastroenteritis
outbreaks in Asia, Europe, South America and Tunisia [11,
12, 14, 18, 21].
PKV (S-1-HUN) was identiﬁed in domestic pigs in
Hungary in 2008 [16, 17]. The detection of PKV-like
sequences in pig feces has been reported recently in several
countries in Asia, Europe and South America [1, 6, 16, 25].
Bovine kobuvirus (BKV) (strain U-1) was ﬁrst recog-
nized in 2003 as a cytopathic contaminant in a culture
medium of HeLa cells in Japan . Subsequently, it was
identiﬁed in fecal samples of clinically healthy cattle .
The RNA genome of the U-1 strain is 8374 nucleotide in
length and contains a large open reading frame coding for a
single polyprotein (2463 aa) that is cleaved post-transla-
tionally into the typical picornavirus structural proteins
VP0, VP3, VP1, and nonstructural proteins 2A, 2B, 2C,
3A, 3B, 3C and 3D. Genetic identity on the coding regions
between AiV, PKV and BKV viruses ranges from 34.0 %
(3B region) to 74.0 % (3D region) [17,
Since their ﬁrst identiﬁcation, BKVs have also been
detected in Thailand , Korea [4, 13], Brazil , Hungary
, Belgium  and the Netherlands , suggesting that
these viruses have a worldwide distribution in cattle pop-
ulations. In addition, they have been detected recently in
domestic sheep in Hungary and Brazil [1, 19].
BKVs are suspected to play a role in the pathogenesis of
enteritis in calves. BKV-like sequences have been detected
in diarrheic cattle in Thailand , Belgium  and Korea
. However, these viruses are not included routinely in
the diagnostic algorithms for enteric diseases of calves and
their real impact in the ﬁeld is unclear. Thus, epidemio-
logical information on the distribution of BKVs in cattle
populations is still limited.
B. Di Martino (&) Á F. Di Proﬁo Á C. Ceci Á
M. G. Pistilli Á F. Marsilio
Department of Scienze Biomediche Comparate,
Faculty of Veterinary Medicine, University of Teramo,
Piazza Aldo Moro, 45, 64100 Teramo, Italy
E. Di Felice
Department of Scienze Cliniche Veterinarie,
University of Teramo, Teramo, Italy
Arch Virol (2012) 157:2393–2396