Natural and Experimental Enteric Pathogen Contamination of Insects
(last updated 9/21/2011)
Two tables are included within this file:
1) a table detailing studies where insects captured under natural conditions were assayed for the presence of pathogens; and
2) a table detailing studies where insects were experimentally exposed to enteric pathogens and examination of the fate of
those pathogens
Reviews
 Graczyk T,K., R. Knight, and L. Tamang. 2005. Mechanical transmission of human protozoan parasites by insects.
Clin. Microbiol. Rev. 18:128-132.
 Wales, A.D., J.J. Carrique-Mas, M. Rankin, B. Bell, B.B. Thind, and R.H. Davies. 2010. Review of the carriage of
zoonotic bacteria by arthropods, with special reference to Salmonella in mites, flies and litter beetles. Zoonoses and
Public Health 57:299-314.
Natural contamination
Alam, M.J. and L. Zurek. 2004. Association of Escherichia coli O157:H7 with houseflies on a cattle farm. Appl.
Environ. Microbiol. 70:7578-7580.
House flies (Musca domestica L.) were collected from two sites on a cattle farm over a 4-month period. The prevalence of E.
coli O157:H7 was 2.9 and 1.4% in house flies collected from feed bunks and a cattle feed storage shed, respectively. E. coli
O157:H7 counts ranged from 3.0 x 10 1 to 1.5 x 105 CFU among the positive house flies. Large populations of house flies on
cattle farms may play a role in the dissemination of E. coli O157:H7 among animals and to the surrounding environment. The
dispersal range of house flies is usually 0.5 to 2 miles, although distances as great as 10 to 20 miles have been reported.
Caldwell, K.N., B.B. Adler, G.L. Anderson, P.L. Williams, and L.R. Beuchat. 2003. Ingestion of Salmonella enterica
serotype Poona by a free-living nematode, Caenorhabditis elegans, and protection against inactivation by produce
sanitizers. Appl. Environ. Microbiol. 69:4103-4110.
Protection of C. elegans-ingested Salmonella enterica serotype Poona occurred when sanitizers (20 ppm chlorine, 850 or 1200
ppm Sanova, 20 or 40 ppm Tsunami 200, or 2% acetic acid) were applied to lettuce.
Graczyk, T.K., R. Fayer, R. Knight, B. Mhangami-Ruwende, J.M. Trout, A.J. Da Silva, and N.J. Pieniazek. 2000.
Mechanical transport and transmission of Cryptosporidium parvum oocysts by wild filth flies. Am. J. Trop. Med. Hyg.
63:178-183.
Wild filth flies were collected from traps left for 7-10 days in a barn with or without a calf shedding Cryptosporidium parvum
Genotype 2. The oocysts of C. parvum transported on the flies’ exoskeletons and eluted from their droplets left on visited
surfaces and were infectious for mice. The mean number of oocysts carried by a fly varied from 4 to 131 and the total oocyst
number per collection varied from 56 to approximately 4.56 x 10 3. Molecular data showed that the oocysts shed by infected
calves were carried by flies for at least 3 weeks.
Holt, P.S., C.J. Geden, R.W. Moore, and R.K. Gast. 2007. Isolation of Salmonella enterica serovar Enteritidis from
houseflies (Musca domestica) found in rooms containing Salmonella serovar Enteritidis-challenged hens. Appl.
Environ. Microbiol. 73:6030-6035.
48 h after houseflies released into rooms containing Salmonella-contaminated hens, 40 to 50% of flies were contaminated. At
4, 7 and 15 days postexposure, the % of flies positive for Salmonella were 50%, 70%, and 30%, respectively. An aqueous
rinse failed to recover surface contamination, however, 0.5% detergent incorporated into the rinse, led to high recoveries of
bacteria. Salmonella serovar Enteritidis was isolated routinely from the fly gut, on rare occasions from the crop, and never
from the salivary gland. Force feeding hens contaminated flies resulted in gut colonization of a third of the birds; however,
release of contaminated flies into a room of uncontaminated chickens failed to result in colonization of any of the subject
birds.
Kopanic, R.J., Jr., B.W. Sheldon, and C.G. Wright. 1994. Cockroaches as vectors of Salmonella: Laboratory and field
trials. J. Food Prot. 57:125-132.
American cockroaches sampled at a commercial poultry feed mill and hatchery.
11.1% of 45 feed mill and 17.8% of 45 hatchery cockroach samples were positive for S. Typhimurium.
Lacharme-Lora, L., S.E. Perkins, T.J. Humphrey, P.J. Hudson, and V. Salisbury. 2009. Use of bioluminescent
bacterial biosensors to investigate the role of free-living helminthes as reservoirs and vectors of Salmonella. Environ.
Microbiol. Rept. 1:198-207.
Inside helminthes, Salmonella exhibited enhanced survival when exposed to UV irradiation.
Olsen, A.R.and T.S. Hammack. 2000. Isolation of Salmonella spp. from the housefly Musca domestica L., and the dump
fly, Hydrotaea aenescens (Wiedemann) (Diptera: Muscidae) at caged-layer houses. J. Food Prot. 63:958-960.
Compiled by Marilyn Erickson, Center for Food Safety, University of Georgia
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Page 1
Natural and Experimental Enteric Pathogen Contamination of Insects
(last updated 9/21/2011)
18.2% of 22 samples positive for Salmonella.
75% of positive samples were from housefly pooled samples and the remainder from the dump fly pooled samples
Skov, M.N., A.G. Spencer, B. Hald, L. Petersen, B. Nauerby, B. Carstensen, and M. Madsen. 2004. The role of litter
beetles as potential reservoir for Salmonella enterica and thermophilic Campylobacter spp. between broiler flocks.
Avian Dis. 48:9-18.
Beetles in broiler houses infrequently are positive for Salmonella. However, transmission of S. Indiana between two
consecutive broiler flocks can coincide with the presence of Salmonella-contaminated beetles in the empty period, indicating
that the beetles were the reservoir of S. Indiana between the two flocks. Concerning Campylobacter, the results suggest that
beetles do not play a significant role as a reservoir of Campylobacter from one rotation to the next.
Skov, M.N., J.J. Madsen, C. Rahbek, J. Lodal, J.B. Jespersen, J.C. Jørgensen, H.H. Dietz, M. Chriél, and D.L.
Baggesen. 2008. Transmission of Salmonella between wildlife and meat-production animals in Denmark. J. Appl.
Microbiol. 105:1558-1568.
22.6% of 31 pooled insect samples were positive for Salmonella.
Sproston, E.L., M. Macrae, I.D. Ogden, M.J. Wilson, and N.J.C. Strachan. 2006. Slugs: Potential novel vectors of
Escherichia coli O157. Appl. Environ. Microbiol. 72:144-149.
0.21% of 33 pooled field slug samples collected from an Aberdeenshire sheep farm were positive
Williams, A.P., P. Roberts, L.M. Avery, K. Killham, and D.L. Jones. 2006. Earthworms as vectors of Escherichia coli
O157:H7 in soil and vermicomposts. FEMS Microbiol. Ecol. 58:54-64.
Anecic earthworms such as Lumbricus terrestris maintain deep vertical burrows whereas epigeic species such as
Dendrobaena veneta inhabit surface organic layers. In this study, E. coli O157:H7 movement by L. terrestris was limited to a
vertical plane, whereas movement by D. veneta was observed in the horizontal plane. Bacterial movement may be attributed
to both worm excretion and to carriage on worm exterior; although the relative proportions attributable to each were not
determined. The gut transit time in most earthworms is approximately 1-5 h and may prove sufficient to allow partial
bacterial growth or for the resuscitation of VBNC bacteria. Thus, this study also suggested that earthworm digestion and
presence may lead to temporarily higher numbers of E. coli O157:H7 in some substrates, especially soil. Despite this initial
proliferation, long-term persistence of E. coli O157:H7 in soil and compost was unaffected by the presence of earthworms.
Experimental contamination
Reference
Expt. Details
Results
Ahmad, A., T.G. Nagaraja, and L.
Zurek. 2007. Transmission of
Escherichia coli O157:H7 to cattle by
house flies. Prev. Vet. Med. 80:74-81.
Eight calves were individually exposed
to house flies that were orally inoculated
with a mixture of 4 strains of E. coli
O157:H7 for 48 h.
On day 1 after the exposure, fecal
samples of all 8 calves and drinking
water samples of 5 of 8 calves exposed
to inoculated flies tested positive for E.
coli O157:H7. The concentration in
feces ranged over time from detectable
only by enrichment (<102) to up to 1.1 x
106 CFU/g. Feces of all calves
remained positive for E. coli O157:H7
up to 11 days after the exposure and
62% were positive until the end of the
experiment.
Amaravadi, L., M.S. Bisesi, and R.F.
Bozarth. 1990. Vermial virucidal
activity: Implications for
management of pathogenic biological
wastes on land. Biological Wastes
34:349-358.
5 to 6 earthworms added to a dish which
contained cellulose saturated with a
virus-buffer suspension at pH 7.0
containing virus (0.025 to 0.5 mg).
Excreted castings were analyzed for
structurally intact virus protein using
enzyme-linked immunosorbent assay
(ELISA) and virus infectivity by local
lesion assays.
Reductions in the infectivity of both
cowpea mosaic virus and tobacco
mosaic (model agents) occurred when
the earthworm (Eisenia fetida) were fed
virus suggesting that earthworms may
possess a virucidal enzyme system and,
accordingly, may contribute to the
inactivation of pathogenic viruses
potentially associated with land
application of sewage sludges and
livestock manures.
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Page 2
Natural and Experimental Enteric Pathogen Contamination of Insects
(last updated 9/21/2011)
Reference
Expt. Details
Results
Anderson, G.L., K.N. Caldwell, L.R.
Beuchat, and P.L. Williams. 2003.
Interaction of a free-living soil
nematode, Caenorhabditis elegans,
with surrogates of foodborne
pathogenic bacteria. J. Food Prot.
66:1543-1549.
3-day-old adult worms placed on an
agar medium having discrete areas
containing cultures of E. coli, an
avirulent strain of Salmonella
Typhimurium, Listeria welshimeri, and
Bacillus cereus.
Over 90% of worms entered colonies
within 16 min after inoculation. Worms
survived and reproduced with the use of
nutrients derived from all test bacteria.
Development was slightly slower for
worms fed gram-positive bacteria than
for worms fed gram-negative bacteria.
Worms that fed for 24 h on bacterial
lawns formed on tryptic soy agar
dispersed bacteria over a 3-h period
when they were transferred to a
bacteria-free agar surface.
Anderson, G.L., S.J. Kenney, P.D.
Millner, L.R. Beuchat, and P.L.
Williams. 2006. Shedding of
foodborne pathogens by
Caenorhabditis elegans in compostamended and unamended soil. Food
Microbiol. 23:146-153.
Worms were fed on E. coli O157:H7
and then inoculated into soil and soil
amended with turkey manure compost
E. coli O157:H7 was detected at 4 and 6
days post inoculation in compostamended and unamended soil.
Populations of C. elegans persisted in
compost-amended soil for at least 7
days, but declined in unamended soil.
Populations of E. coli O157:H7 in soil
amended with turkey manure compost
were significantly higher than those in
unamended soil.
Caldwell, K.N., G.L. Anderson, P.L.
Williams, and L.R. Beuchat. 2003.
Attraction of a free-living nematode,
Caenorhabditis elegans, to foodborne
pathogenic bacteria and its potential
as a vector of Salmonella Poona for
preharvest contamination of
cantaloupe. J. Food Prot. 66:19641971.
20 to 30 adult worms were placed on the
surface of K agar midway between a 24h bacterial colony (7 strains of E. coli
O157:H7; 8 serotypes of Salmonella, 6
strains of L. monocytogenes),
uninoculated tryptic soy broth, or
cantaloupe juice. Numbers of worms
migrating to the respective areas were
counted.
The nematode was attracted to colonies
of all test pathogens and survived and
reproduced within colonies for up to 7
days. C. elegans was not attracted to
cantaloupe juice.
Adult worms that had been immersed in
a suspension of Salmonella Poona were
deposited 1 or 3 cm below the surface of
soil on which a piece of cantaloupe rind
was placed.
De Jesús, A.J., A.R. Olsen, J.R. Bryce,
and R.C. Whiting. 2004. Quantitative
contamination and transfer of
Escherichia coli from foods by
houseflies, Musca domestica L.
(Diptera: Muscidae). Int. J. Food
Microbiol. 93:259-262.
The presence of Salmonella Poona was
evident more quickly on rinds
positioned on soil beneath which C.
elegans inoculated with Salmonella
Poona was initially deposited than on
rinds deposited on soil beneath which
Salmonella Poona alone was deposited.
40-60 houseflies were transferred to a
sterile cage containing E. colicontaminated potato salad or sugar-milk
solution (8 log CFU/g) or surfacecontaminated steak. After 30 min, E.
coli on the flies were enumerated.
43%, 53%, and 62% of the flies had
detectable E. coli (> 1.7 log CFU/fly)
with geometric mean carriage of 2.9, 3.8
and 2.2 log CFU/fly following exposure
to contaminated sugar/milk, steak, and
potato salad, respectively.
Contaminated flies were transferred to a
sterile jar and transfer to the surfaces of
that jar was determined.
Contaminated flies can cross
contaminate other surfaces with
approximately 0.001% of the original
numbers in the contaminated source.
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Page 3
Natural and Experimental Enteric Pathogen Contamination of Insects
(last updated 9/21/2011)
Reference
Expt. Details
Results
Fayer, R., J.M. Trout, E. Walsh, and
R. Cole. 2000. Rotifers ingest oocysts
of Cryptosporidium parvum. J.
Eukaryot. Microbiol. 47:161-163.
10-20 rotifers were placed into 11-mm
diameter wells containing 2 x 104
oocysts.
Rotifers of all six genera (Philodina,
Monostyla, Epiphanes, Euchlanis,
Brachionus, and Asplanchna) were
observed ingesting oocysts. Euchlanis
and Epiphanes were observed excreting
boluses containing up to 8 oocysts;
however, it was not determined whether
rotifers digested or otherwise rendered
oocysts nonviable.
Gibbs, D.S., G.L. Anderson, L.R.
Beuchat, L.K. Carta, and P.L.
Williams. 2005. Potential role of
Diploscapter sp. strain LKC25, a
bacterivorous nematode from soil, as
a vector of food-borne pathogenic
bacteria to preharvest fruits and
vegetables. Appl. Environ. Microbiol.
71:2433-2437.
A suspension of Diploscapter sp. strain
LKC25, containing 25 to 50 worms, was
placed on the surface of a tryptic soy
agar plate such that it was equidistant
from sites which had been inoculated
with one of 4 bacteria: E. coli
O157:H7, S. enterica, L.
monocytogenes, or E. coli. The plate
was incubated at 21°C for up to 24 h
and location of the worms on the surface
monitored by a computer-captured
image technique.
85% of the worms had migrated to
bacterial colonies of E. coli O157:H7,
Salmonella enterica serotype Poona,
and Listeria monocytogenes that were
initially placed 0.5 to 1 cm and within
24 h, more than 90% of the worms were
embedded in colonies. When these
exposed worms were added to soil or a
mixture of soil and composted turkey
manure, the worms were capable of
shedding the pathogenic bacteria into
the soil.
Gourabathini, P., M.T. Brandl, K.S.
Redding, J.H. Gunderson, and S.G.
Berk. 2008. Interactions between
food-borne pathogens and protozoa
isolated from lettuce and spinach.
Appl. Environ. Microbiol. 74:25182525.
Initial # of protozoan cells/ml ranged
from 2.0 to 4.3 x 103 cells/ml and were
suspended in Tris-buffered saline
solution along with the pathogen that
had been grown for 24-h and
centrifuged.
Distribution of types of protozoa among
produce samples was heterogeneous
containing flagellates, amoebae, and
ciliates. Vesicles were produced by
Glaucoma sp. with Salmonella enterica,
Escherichia coli O157:H7, and Listeria
monocytogenes, although L.
monocytogenes resulted in the smallest
number per ciliate. Vesicle production
was observed also during grazing of
Tetrahymena on E. coli O157:H7 and S.
enterica but not during grazing on L.
monocytogenes, in vitro and on leaves.
Such vesicles would only be produced
when the surface of produce is wet in
order to enable Tetrahymena to graze by
filter feeding on bacteria that are free in
the water film on the plant surface.
These conditions may be met in the
preharvest environment during dew,
rain, or overhead irrigation. 4 h after
addition of spinach extract, the bacteria
multiplied and escaped the vesicles. In
contrast, Colpoda steinii and the
amoeba did not produce vesicles from
any of the enteric pathogens, nor were
pathogens trapped within their cysts.
Compiled by Marilyn Erickson, Center for Food Safety, University of Georgia
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Natural and Experimental Enteric Pathogen Contamination of Insects
(last updated 9/21/2011)
Reference
Expt. Details
Results
Huamanchay, O., L. Genzlinger, M.
Iglesias, and Y.R. Ortega. 2004.
Ingestion of Cryptosporidium oocysts
by Caenorhabditis elegans. J.
Parasitol. 90:1176-1178.
Between 100 and 200 adult nematodes
were placed on K-agar plates with 2 x
106 fluorescein isothiocyanate-tagged C.
parvum oocysts. After specific
incubation times, worms were washed
and observed by UV and differential
interference contrast (DIC) microscopy.
70 to 85% of worms ingested between 0
and 500 oocysts after 1 and 2 h
incubation with oocysts. Most of the
nematodes ingested between 101 and
200 oocysts after 2 h. Intact oocysts and
empty shells were excreted by
nematodes. Adult C. elegans containing
C. parvum kept in water were infective
for mice. Cyclospora oocysts were not
ingested by C. elegans.
Janisiewicz, W.J., W.S. Conway,
M.W. Brown, G.M. Sapers, P.
Fratamico, and R.L. Buchanan. 1999.
Fate of Escherichia coli O157:H7 on
fresh-cut apple tissue and its potential
for transmission by fruit flies. Appl.
Environ. Microbiol. 65:1-5.
Ten fruit flies were put in a chamber
and allowed to feed on a filter paper
soaked in a suspension of E. coli
ATCCF-11775 at 8 x 108 CFU/ml in
20% apple juice. Fruit flies were
sampled after 2, 6, 24 and 48 h.
Fruit flies were easily contaminated
externally and internally with E. coli
after contact with the bacterium source.
The flies transmitted this bacterium to
uncontaminated apple wounds.
Kenney, S.J., G.L. Anderson, P.L.
Williams, P.D. Millner, and L.R.
Beuchat. 2005. Persistence of
Escherichia coli O157:H7, Salmonella
Newport, and Salmonella Poona in
the gut of a free-living nematode,
Caenorhabditis elegans, and
transmission to progeny and
uninfected nematodes. Int. J. Food
Microbiol. 101:227-236.
Worms were fed for 3 h at 20°C on a
lawn of E. coli O157:H7, S. Newport, or
S. Poona. Worms were incubated at 4,
20 or 37°C for up to 5 days. At
temperatures of 4 or 20°C, incubation
conditions also varied relative humidity
(33%, 75%, or 98%).
Initial populations within worms (2.8 to
3.2 log CFU/worm) significantly
increased by up to 2.93 log CFU/worm
within 1 day at 20°C on K agar and
remained constant for an additional 4
days. When worms were placed on
Bacto agar, populations of ingested
pathogens remained constant at 4°C,
decreased significantly at 20°C, and
increased significantly at 37°C within 3
days. Fewer cells of the pathogens
survived incubation at 33% relative
humidity compared to higher relative
humidities. S. Newport was isolated
from C. elegans two generations
removed from exposure to the pathogen.
Kenney, S.J., G.L. Anderson, P.L.
Williams, P.D. Millner, and L.R.
Beuchat. 2006. Migration of
Caenorhabditis elegans to manure and
manure compost and potential for
transport of Salmonella newport to
fruits and vegetables. Int. J. Food
Microbiol. 106:61-68.
Bovine manure and bovine manure
compost inoculated with S. Newport
(8.6 log CFU/g) were separately placed
in the bottom of a glass jar and covered
with a layer of soil (5 cm) inoculated
(50 worms/g) or not inoculated with C.
elegans. A piece of lettuce, strawberry,
or carrot was placed on top of the soil
before jars were sealed and held at 20°C
for up to 10 days.
The pathogen was detected on lettuce,
strawberry, and carrot within 1, 7 and 1
day, respectively, when initially present
in bovine manure compost (detection by
enrichment only, no attempts at
enumeration)
Kopanic, R.J., Jr., B.W. Sheldon, and
C.G. Wright. 1994. Cockroaches as
vectors of Salmonella: Laboratory
and field trials. J. Food Prot. 57:125132.
2 ml of a S. typhimurium culture (~ 7-8
log CFU/ml) was inoculated onto five
food pellets and then 20 cockroaches
placed with these pellets in an
environmental chamber. After 24, 48,
72, and 96 h, cockroaches were
individually sampled.
American and Oriental cockroaches
were contaminated twice as often as
German cockroaches. Crosscontamination between infected and
non-infected cockroaches was most
frequent within 24 h of contamination
event.
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Natural and Experimental Enteric Pathogen Contamination of Insects
(last updated 9/21/2011)
Reference
Expt. Details
Results
Mumcuoglu, K.Y., J. Miller, M.
Mumcuoglu, M. Friger, and M.
Tarshis. 2001. Destruction of bacteria
in the digestive tract of the maggot of
Lucilia sericata (Diptera:
Calliphoridae). J. Med. Entomol.
38:161-166.
15-25 sterile maggots were transferred
to a piece of gauze and fed for 2-15 h on
5 ml of brain heart broth containing 108
– 1010 gfp-labeled E. coli/ml. The
maggots were viewed with a laser
scanning confocal microscope.
Preliminary studies using a vital dye
showed that food ingested by the
maggots passed through their intestine
within 1-1.5 h. It was shown that 66.7%
of the crops, 52.8% of the midgets,
55.6% of the anterior hindguts, and
17.8% of posterior hindguts harbored
living bacteria. With passage through
the digestive tract, the majority of
bacteria are killed; however, small
numbers of bacteria may remain in the
feces.
Petridis, M., M. Bagdasarian, M.K.
Waldor, and E. Walker. 2006.
Horizontal transfer of Shiga toxin and
antibiotic resistance genes among
Escherichia coli strains in house fly
(Diptera: Muscidae) gut. J. Med.
Entomol. 43:288-295.
House flies were immobilized and force
fed suspensions of defined, donor
strains of E. coli containing
chloramphenicol resistance genes on a
plasmid, or lysogenic bacteriophageborn Shiga toxin gene stx1. Recipient
strains were E. coli lacking these mobile
elements and genes but having
rifampicin as a selectable marker.
Findings show that genes encoding
antibiotic resistance or toxins will
transfer horizontally among bacteria in
the house fly gut via plasmid transfer or
phage transduction.
Sasaki, T., M. Kobayashi, and N.
Agui. 2000. Epidemiological potential
of excretion and regurgitation by
Musca domestica (Diptera: Muscidae)
in the dissemination of Escherichia
coli O157:H7 to food. J. Med.
Entomol. 37:945-949.
House flies (adult, 6-8 old) fed on
tryptic soy broth containing ~ 109
CFU/ml E. coli O157:H7 for 30 min.
The number of E. coli O157:H7 in an
excreted droplet was ~ 104 1 h after
bacterial feeding, > 1.8 x 105 3 h after
feeding, and then drastically decreased
after 24 h. E. coli O157:H7 persisted in
the crop of house flies for at least 4
days.
Sela, S., D. Nestel, R. Pinto, E.
Nemny-Lavy, and M. Bar-Joseph.
2005. Mediterranean fruit fly as a
potential vector of bacterial
pathogens. Appl. Environ. Microbiol.
71:4052-4056.
Adult flies (ca. 2 d old) were exposed to
a 20% sucrose solution containing 6-9
log CFU/ml of E. coli.
Flies exposed to fecal material enriched
with GFP-tagged E. coli were
contaminated and were capable of
transmitting E. coli to intact apples in a
cage model system. Flies inoculated
with E. coli harbored the bacteria for up
to 7 days following contamination.
Microscopic analysis suggested that the
main organ involved in bacterial uptake
is the fly's mouthparts.
Sproston, E.L., M. Macrae, I.D.
Ogden, M.J. Wilson, and N.J.C.
Strachan. 2006. Slugs: Potential novel
vectors of Escherichia coli O157.
Appl. Environ. Microbiol. 72:144-149.
Slugs were inoculated by placement in a
petri dish with 5 ml of a nalidixic acidresistant E. coli suspension (5.8-6.0 x
109 CFU/ml) and survival on slug
surface and feces was measured.
Viable E. coli was detected on the slug
surface for up to 14 days. Slugs that
had been fed E. coli shed viable bacteria
in their feces with numbers showing a
short but statistically significant linear
log decline. Further, it was found that
E. coli persisted for up to 3 weeks in
excreted slug feces.
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Page 6
Natural and Experimental Enteric Pathogen Contamination of Insects
(last updated 9/21/2011)
Reference
Expt. Details
Results
Strother, K.O., C.Dayton Steelman,
and E.E. Gbur. 2005. Reservoir
competence of lesser mealworm
(Coleoptera: Tenebrionidae) for
Campylobacter jejuni
(Campylobacterales:
Campylobacteraeae). J. Med.
Entomol. 42:42-47
Adult and larval beetles were swabbed
with C. jejuni (9 log CFU/ml) and
survival determined for up to 72 h.
Adult and larval beetles drank from a
solution containing C. jejuni (9 log
CFU/ml) and duration of internal
carriage and fecal shedding determined
for up to 144 h.
3-d-old chickens fed either 1 or 10
infected beetles and cloacal swabs tested
periodically for Campylobacter.
C. jejuni was detected on the exterior of
larval beetles for up to 12 h.
C. jejuni was detected in the interior of
larvae for 72 h and from the feces of
larvae for 12 h after exposure.
90% of the birds that consumed a single
adult or larval beetle became
Campylobacter-positive, whereas 100%
of the birds that consumed 10 adults or
larvae became positive.
Templeton, J.M., A.J. De Jong, P.J.
Blackall, and J.K. Miflin. 2006.
Survival of Campylobacter spp. in
darkling beetles (Alphitobius
diaperinus) and their larvae in
Australia. Appl. Environ. Microbiol.
72:7909-7911.
Beetles were either sprayed with a
Campylobacter culture (2.6 x 108
CFU/ml) or allowed to feed for 24 h on
an apple (soaked in the Campylobacter
culture for 20 min). Beetles were tested
every 24 h for Campylobacter by direct
culture and enrichment.
45% of 20 of spray-inoculated beetles
were still positive after 72 h but only
5.6% of 18 beetles were positive after
96 h.
14% of 20 feed-inoculated beetles were
positive after 48 h but were all negative
at later time points.
Compiled by Marilyn Erickson, Center for Food Safety, University of Georgia
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