bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Дек. 14, 2023
Abstract
Cyathostomins
are
globally
important
equine
parasites,
responsible
for
both
chronic
and
acute
pathogenic
effects.
The
occurrence
of
mixed
infections
with
numerous
cyathostomin
species
hinders
our
understanding
parasite
epidemiology,
host-parasite
dynamics
pathogenicity.
There
have
been
few
studies
occurring
in
horses
Ireland,
where
temperate
climatic
conditions
year-round
rainfall
provide
suitable
infection
grazing
animals
bursate
nematodes.
Here,
we
amplified
sequenced
the
ITS-2
region
adult
worms
harvested
at
post-mortem
from
11
between
August
2018
June
2020,
recorded
prevalence
abundance
recovered
caecum,
right
ventral
colon
left
dorsal
colon,
using
BLAST
IDTAXA
taxonomic
attribution.
Phylogenetic
relationships
community
composition
were
also
compared
other
relevant
studies,
including
a
global
meta-analysis.
Overall,
results
agree
previous
that
there
does
not
seem
to
be
major
difference
equids
different
geographical
regions.
We
confirmed
workers
relation
difficulties
discriminating
Cylicostephanus
calicatus
Coronocyclus
coronatus
on
basis
sequences.
International Journal for Parasitology Drugs and Drug Resistance,
Год журнала:
2023,
Номер
24, С. 100517 - 100517
Опубликована: Ноя. 29, 2023
This
study
quantified
the
extent
of
anthelmintic
resistance
(AR)
to
ascarid
and
strongylid
nematodes
among
commonly
used
anthelmintics
in
Australian
Thoroughbred
horses.
Faecal
egg
count
reduction
tests
(FECRTs,
n
=
86)
reappearance
period
(ERP)
were
conducted
on
22
farms
across
Australia.
counts
(FECs)
determined
using
modified
McMaster
technique,
percent
faecal
(%FECR)
was
calculated
Bayesian
hierarchical
model
hybrid
Frequentist/Bayesian
analysis
method.
The
results
interpreted
old
(published
1992)
new
(2023)
research
guidelines
World
Association
for
Advancement
Veterinary
Parasitology
(WAAVP).
species
composition
detected
utilising
a
DNA-metabarcoding
method
pre-
post-treatment
samples.
Resistance
observed
single-active
combination
anthelmintics,
including
ivermectin
(IVM
%FECR
range:
82%–92%;
95%
lower
credible
interval
(LCI)
80%–90%),
abamectin
(ABM:
73%–92%;
65%–88%),
moxidectin
(MOX:
89%–91%;
84%–89%),
oxfendazole
(OFZ:
0%–56%;
0%–31%)
its
with
pyrantel
(OFZ
+
PYR:
0%–82%;
0%–78%).
Parascaris
spp.
IVM
(10%–43%;
0%–36%),
ABM
(0%;
0%)
MOX
0%).
When
thresholds
recommended
by
WAAVP
used,
AR
six
additional
FECRTs
strongylids
three
more
spp.,
introducing
OFZ
PYR
latter.
Shortened
ERPs
(4–6
weeks)
cyathostomins
31
which
not
at
2
weeks
all
tested.
Among
cyathostomins,
Cylicocyclus
nassatus,
Cylicostephanus
longibursatus
Coronocyclus
coronatus
most
prevalent
post-treatment,
whereas
main
appearing
five
following
treatments
macrocyclic
lactones
ashworthi.
After
treatment
PYR,
latter
three,
plus
Cyathostomum
catinatum,
5
post-treatment.
Overall,
highlights
prevalence
both
ascarids
against
products
control
worms
indicate
that
ML
provided
acceptable
efficacy
weeks.
However,
ERP
calculations
suggest
work
less
effectively
than
previously
measured.
It
is
suggested
regularly
monitor
consider
changing
worm
practices
better
manage
Veterinary Parasitology,
Год журнала:
2024,
Номер
328, С. 110168 - 110168
Опубликована: Март 15, 2024
Cyathostomins
are
globally
important
equine
parasites,
responsible
for
both
chronic
and
acute
pathogenic
effects.
The
occurrence
of
mixed
infections
with
numerous
cyathostomin
species
hinders
our
understanding
parasite
epidemiology,
host-parasite
dynamics,
pathogenicity.
There
have
been
few
studies
occurring
in
horses
Ireland,
where
temperate
climatic
conditions
year-round
rainfall
provide
suitable
infection
grazing
animals
bursate
nematodes.
Here,
we
amplified
sequenced
the
ITS-2
region
adult
worms
harvested
at
post-mortem
from
11
between
August
2018
June
2020,
recorded
prevalence
abundance
recovered
caecum,
right
ventral
colon
left
dorsal
colon,
using
BLAST
IDTAXA
taxonomic
attribution.
Phylogenetic
relationships
community
composition
were
also
compared
other
relevant
studies,
including
a
global
meta-analysis.
Overall,
results
agree
previous
that
there
does
not
seem
to
be
major
difference
equids
different
geographical
regions.
We
confirmed
workers
relation
difficulties
discriminating
Cylicostephanus
calicatus
Coronocyclus
coronatus
on
basis
sequences.
Veterinary Parasitology,
Год журнала:
2023,
Номер
325, С. 110094 - 110094
Опубликована: Дек. 3, 2023
This
study
reports
the
spatial
and
temporal
distribution
of
ascarid
strongylid
nematodes
in
Thoroughbred
horses
by
age
category
across
different
climatic
zones
Australia
over
an
18-month
period.
Faecal
samples
(n
=
2046)
from
individual
were
analysed
using
modified
McMaster
technique
for
faecal
egg
counts
(FECs).
Strongylids
identified
PCR-directed
next-generation
sequencing
second
internal
transcribed
spacer
(ITS-2)
nuclear
ribosomal
DNA.
Yearlings
had
highest
prevalence
(82%)
strongyle
eggs
followed
weanlings
(79%),
foals
(58%),
wet
mares
(49%)
dry
(46%).
For
Parascaris
spp.,
(35%)
(21%)
yearlings
(10%).
The
mean
FECs
spp.
observed
(525
per
gram
[EPG]
faeces)
while
those
strongyles
(962
EPG).
Among
that
classified
as
adults
at
time
sampling,
77%
(860
1119)
low
(i.e.,
<250
EPG)
egg-shedders.
Mean
FEC
Mediterranean
(818
summer
(599
EPG),
winter
(442
non-seasonal
(413
rainfall
zones.
Twenty-six
nematode
species
detected,
with
Cylicostephanus
longibursatus
(26.5%),
Cylicocyclus
nassatus
(23.7%)
Coronocyclus
coronatus
(20.5%)
being
most
frequently
detected
species.
Their
richness
relative
abundance
varied
horse
age,
season
zone.
In
addition,
Strongylus
equinus
Triodontophorus
(T.
brevicauda
T.
serratus)
also
detected.
comprehensive
elucidates
(climatic
zone)
seasonal)
trends
burdens
intestinal
Australian
non-invasive
conventional
molecular
methods.
information
presented
this
is
crucial
developing
integrated
management
strategies
to
control
parasites
farmed
horses.
Parasitology,
Год журнала:
2024,
Номер
unknown, С. 1 - 18
Опубликована: Дек. 12, 2024
Abstract
Identifying
factors
that
drive
among-individual
variation
in
mixed
parasitic
infections
is
fundamental
to
understanding
the
ecology
and
evolution
of
host–parasite
interactions.
However,
a
lack
non-invasive
diagnostic
tools
quantify
has
restricted
their
investigation
for
host
populations
wild.
This
study
applied
DNA
metabarcoding
on
parasite
larvae
cultured
from
faecal
samples
characterize
strongyle
320
feral
horses
Sable
Island,
Nova
Scotia,
Canada,
2014
test
influence
(age,
sex
reproductive/social
status)
environmental
(location,
local
density
social
group
membership)
variation.
Twenty-five
species
were
identified,
with
individual
ranging
3
18
mean
richness
(±1
s.d.
)
10.8
±
3.1.
Strongyle
eggs
shed
faeces
dominated
by
small
(cyathostomins)
young
individuals,
transitioning
large
strongyles
(
Strongylus
spp.)
adults.
Egg
counts
highest
individuals
west
or
centre
island
most
species.
Individuals
same
had
similar
communities,
supporting
hypothesis
shared
environment
may
assemblages.
Other
such
as
horse
density,
sex,
date
status
minimal
impacts
infection
patterns.
demonstrates
can
be
dynamic
across
ontogeny
space
emphasizes
need
consider
species-specific
patterns
when
investigating
infections.
International Journal for Parasitology Drugs and Drug Resistance,
Год журнала:
2024,
Номер
24, С. 100523 - 100523
Опубликована: Фев. 9, 2024
Cyathostomins
are
the
most
prevalent
parasitic
nematodes
of
grazing
horses.
They
responsible
for
colic
and
diarrhea
in
their
hosts.
After
several
decades
exposure
to
synthetic
anthelmintics,
they
have
evolved
become
resistant
compounds.
In
addition,
drug-associated
environmental
side-effects
question
use
field.
Alternative
control
strategies,
like
bioactive
forages,
needed
face
these
challenges.
Among
these,
chicory
(Cichorium
intybus,
Puna
II
cultivar
(cv.))
is
known
convey
anthelmintic
compounds
may
cyathostomins
To
challenge
this
hypothesis,
we
measured
fecal
egg
counts
rate
larval
development
20
naturally
infected
young
saddle
horses
(2-year-old)
either
(i)
a
pasture
sown
with
(n
=
10)
or
(ii)
mesophile
grassland
at
same
stocking
(2.4
livestock
unit
(LU)/ha).
The
period
lasted
45
days
prevent
horse
reinfection.
Horses
group
mostly
grazed
(89%
bites),
while
those
mainly
grasses
(73%).
excretion
decreased
both
groups
throughout
experiment.
Accounting
trajectory,
count
reduction
(FECR)
individuals
relative
increased
from
72.9%
day
16–85.5%
end
study.
feces
on
was
reduced
by
more
than
60%
d31
compared
individuals.
Using
metabarcoding
approach,
also
evidenced
significant
decrease
cyathostomin
species
abundance
chicory.
Chicory
extract
enriched
sesquiterpenes
lactones
tested
two
isolates.
estimated
IC50
high
(1
3.4
mg/ml)
varied
according
pyrantel
sensitivity
status
worm
isolate.
We
conclude
that
(cv.
II)
promising
strategy
reducing
contribute
lower
reliance
anthelmintics.
underpinning
modes
action
remain
be
explored
further.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Июль 19, 2023
Cyathostomins
are
a
complex
of
50
intestinal
parasite
species
infecting
horses
and
wild
equids.
The
massive
administration
modern
anthelmintic
drugs
has
increased
their
relative
abundance
in
horse
helminth
communities
selected
drug-resistant
isolates
worldwide.
Cylicocyclus
nassatus
is
the
most
prevalent
abundant
species.
tedious
identification
isolation
these
worms
have
hampered
studies
biology
that
remain
largely
uncharacterised.
Here
we
leveraged
ultra-low
input
sequencing
protocols
to
build
reference
genome
for
strongyle
Using
this
resource,
established
first
estimates
its
genetic
diversity
population
structure
on
gradient
ranging
from
Ukraine
(close
domestication
area)
North
America,
while
capturing
19th-century
snapshot
C.
Egypt.
Our
results
support
diverse
lowly
structured
global
population.
Modern
populations
displayed
lower
nucleotide
old
African
isolate.
We
identified
candidates
upon
which
pyrantel
(an
drug
used
companion
animals)
selection
likely
applied
field
populations,
highlighting
previously
suspected
genes
coding
nicotinic
acetylcholine
receptor
subunits,
identifying
new
showing
differential
expression
independently
evolved
Caenorhabditis
elegans
lines.
These
offer
resource
widen
current
knowledge
cyathostomin
biology,
unravel
novel
aspects
resistance
mechanisms
provide
candidate
track
field.
