Insect Vectors Pathogen Prevalence by HC12091214928

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									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.
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Natural and Experimental Enteric Pathogen Contamination of Insects
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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.                Eight calves were individually exposed           On day 1 after the exposure, fecal
Zurek. 2007. Transmission of                    to house flies that were orally inoculated       samples of all 8 calves and drinking
Escherichia coli O157:H7 to cattle by           with a mixture of 4 strains of E. coli           water samples of 5 of 8 calves exposed
house flies. Prev. Vet. Med. 80:74-81.          O157:H7 for 48 h.                                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.            5 to 6 earthworms added to a dish which          Reductions in the infectivity of both
Bozarth. 1990. Vermial virucidal                contained cellulose saturated with a             cowpea mosaic virus and tobacco
activity: Implications for                      virus-buffer suspension at pH 7.0                mosaic (model agents) occurred when
management of pathogenic biological             containing virus (0.025 to 0.5 mg).              the earthworm (Eisenia fetida) were fed
wastes on land. Biological Wastes               Excreted castings were analyzed for              virus suggesting that earthworms may
34:349-358.                                     structurally intact virus protein using          possess a virucidal enzyme system and,
                                                enzyme-linked immunosorbent assay                accordingly, may contribute to the
                                                (ELISA) and virus infectivity by local           inactivation of pathogenic viruses
                                                lesion assays.                                   potentially associated with land
                                                                                                 application of sewage sludges and
                                                                                                 livestock manures.

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Natural and Experimental Enteric Pathogen Contamination of Insects
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Reference                                       Expt. Details                                    Results
Anderson, G.L., K.N. Caldwell, L.R.             3-day-old adult worms placed on an               Over 90% of worms entered colonies
Beuchat, and P.L. Williams. 2003.               agar medium having discrete areas                within 16 min after inoculation. Worms
Interaction of a free-living soil               containing cultures of E. coli, an               survived and reproduced with the use of
nematode, Caenorhabditis elegans,               avirulent strain of Salmonella                   nutrients derived from all test bacteria.
with surrogates of foodborne                    Typhimurium, Listeria welshimeri, and            Development was slightly slower for
pathogenic bacteria. J. Food Prot.              Bacillus cereus.                                 worms fed gram-positive bacteria than
66:1543-1549.                                                                                    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.               Worms were fed on E. coli O157:H7                E. coli O157:H7 was detected at 4 and 6
Millner, L.R. Beuchat, and P.L.                 and then inoculated into soil and soil           days post inoculation in compost-
Williams. 2006. Shedding of                     amended with turkey manure compost               amended and unamended soil.
foodborne pathogens by                                                                           Populations of C. elegans persisted in
Caenorhabditis elegans in compost-                                                               compost-amended soil for at least 7
amended and unamended soil. Food                                                                 days, but declined in unamended soil.
Microbiol. 23:146-153.                                                                           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.             20 to 30 adult worms were placed on the          The nematode was attracted to colonies
Williams, and L.R. Beuchat. 2003.               surface of K agar midway between a 24-           of all test pathogens and survived and
Attraction of a free-living nematode,           h bacterial colony (7 strains of E. coli         reproduced within colonies for up to 7
Caenorhabditis elegans, to foodborne            O157:H7; 8 serotypes of Salmonella, 6            days. C. elegans was not attracted to
pathogenic bacteria and its potential           strains of L. monocytogenes),                    cantaloupe juice.
as a vector of Salmonella Poona for             uninoculated tryptic soy broth, or
preharvest contamination of                     cantaloupe juice. Numbers of worms
                                                                                                 The presence of Salmonella Poona was
cantaloupe. J. Food Prot. 66:1964-              migrating to the respective areas were
                                                                                                 evident more quickly on rinds
1971.                                           counted.
                                                                                                 positioned on soil beneath which C.
                                                                                                 elegans inoculated with Salmonella
                                                Adult worms that had been immersed in            Poona was initially deposited than on
                                                a suspension of Salmonella Poona were            rinds deposited on soil beneath which
                                                deposited 1 or 3 cm below the surface of         Salmonella Poona alone was deposited.
                                                soil on which a piece of cantaloupe rind
                                                was placed.
De Jesús, A.J., A.R. Olsen, J.R. Bryce,         40-60 houseflies were transferred to a           43%, 53%, and 62% of the flies had
and R.C. Whiting. 2004. Quantitative            sterile cage containing E. coli-                 detectable E. coli (> 1.7 log CFU/fly)
contamination and transfer of                   contaminated potato salad or sugar-milk          with geometric mean carriage of 2.9, 3.8
Escherichia coli from foods by                  solution (8 log CFU/g) or surface-               and 2.2 log CFU/fly following exposure
houseflies, Musca domestica L.                  contaminated steak. After 30 min, E.             to contaminated sugar/milk, steak, and
(Diptera: Muscidae). Int. J. Food               coli on the flies were enumerated.               potato salad, respectively.
Microbiol. 93:259-262.
                                                Contaminated flies were transferred to a         Contaminated flies can cross
                                                sterile jar and transfer to the surfaces of      contaminate other surfaces with
                                                that jar was determined.                         approximately 0.001% of the original
                                                                                                 numbers in the contaminated source.




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Natural and Experimental Enteric Pathogen Contamination of Insects
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Reference                                       Expt. Details                                    Results
Fayer, R., J.M. Trout, E. Walsh, and            10-20 rotifers were placed into 11-mm            Rotifers of all six genera (Philodina,
R. Cole. 2000. Rotifers ingest oocysts          diameter wells containing 2 x 104                Monostyla, Epiphanes, Euchlanis,
of Cryptosporidium parvum. J.                   oocysts.                                         Brachionus, and Asplanchna) were
Eukaryot. Microbiol. 47:161-163.                                                                 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.                A suspension of Diploscapter sp. strain          85% of the worms had migrated to
Beuchat, L.K. Carta, and P.L.                   LKC25, containing 25 to 50 worms, was            bacterial colonies of E. coli O157:H7,
Williams. 2005. Potential role of               placed on the surface of a tryptic soy           Salmonella enterica serotype Poona,
Diploscapter sp. strain LKC25, a                agar plate such that it was equidistant          and Listeria monocytogenes that were
bacterivorous nematode from soil, as            from sites which had been inoculated             initially placed 0.5 to 1 cm and within
a vector of food-borne pathogenic               with one of 4 bacteria: E. coli                  24 h, more than 90% of the worms were
bacteria to preharvest fruits and               O157:H7, S. enterica, L.                         embedded in colonies. When these
vegetables. Appl. Environ. Microbiol.           monocytogenes, or E. coli. The plate             exposed worms were added to soil or a
71:2433-2437.                                   was incubated at 21°C for up to 24 h             mixture of soil and composted turkey
                                                and location of the worms on the surface         manure, the worms were capable of
                                                monitored by a computer-captured                 shedding the pathogenic bacteria into
                                                image technique.                                 the soil.
Gourabathini, P., M.T. Brandl, K.S.             Initial # of protozoan cells/ml ranged           Distribution of types of protozoa among
Redding, J.H. Gunderson, and S.G.               from 2.0 to 4.3 x 103 cells/ml and were          produce samples was heterogeneous
Berk. 2008. Interactions between                suspended in Tris-buffered saline                containing flagellates, amoebae, and
food-borne pathogens and protozoa               solution along with the pathogen that            ciliates. Vesicles were produced by
isolated from lettuce and spinach.              had been grown for 24-h and                      Glaucoma sp. with Salmonella enterica,
Appl. Environ. Microbiol. 74:2518-              centrifuged.                                     Escherichia coli O157:H7, and Listeria
2525.                                                                                            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.




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Natural and Experimental Enteric Pathogen Contamination of Insects
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Reference                                       Expt. Details                                    Results
Huamanchay, O., L. Genzlinger, M.               Between 100 and 200 adult nematodes              70 to 85% of worms ingested between 0
Iglesias, and Y.R. Ortega. 2004.                were placed on K-agar plates with 2 x            and 500 oocysts after 1 and 2 h
Ingestion of Cryptosporidium oocysts            106 fluorescein isothiocyanate-tagged C.         incubation with oocysts. Most of the
by Caenorhabditis elegans. J.                   parvum oocysts. After specific                   nematodes ingested between 101 and
Parasitol. 90:1176-1178.                        incubation times, worms were washed              200 oocysts after 2 h. Intact oocysts and
                                                and observed by UV and differential              empty shells were excreted by
                                                interference contrast (DIC) microscopy.          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,                 Ten fruit flies were put in a chamber            Fruit flies were easily contaminated
M.W. Brown, G.M. Sapers, P.                     and allowed to feed on a filter paper            externally and internally with E. coli
Fratamico, and R.L. Buchanan. 1999.             soaked in a suspension of E. coli                after contact with the bacterium source.
Fate of Escherichia coli O157:H7 on             ATCCF-11775 at 8 x 108 CFU/ml in                 The flies transmitted this bacterium to
fresh-cut apple tissue and its potential        20% apple juice. Fruit flies were                uncontaminated apple wounds.
for transmission by fruit flies. Appl.          sampled after 2, 6, 24 and 48 h.
Environ. Microbiol. 65:1-5.
Kenney, S.J., G.L. Anderson, P.L.               Worms were fed for 3 h at 20°C on a              Initial populations within worms (2.8 to
Williams, P.D. Millner, and L.R.                lawn of E. coli O157:H7, S. Newport, or          3.2 log CFU/worm) significantly
Beuchat. 2005. Persistence of                   S. Poona. Worms were incubated at 4,             increased by up to 2.93 log CFU/worm
Escherichia coli O157:H7, Salmonella            20 or 37°C for up to 5 days. At                  within 1 day at 20°C on K agar and
Newport, and Salmonella Poona in                temperatures of 4 or 20°C, incubation            remained constant for an additional 4
the gut of a free-living nematode,              conditions also varied relative humidity         days. When worms were placed on
Caenorhabditis elegans, and                     (33%, 75%, or 98%).                              Bacto agar, populations of ingested
transmission to progeny and                                                                      pathogens remained constant at 4°C,
uninfected nematodes. Int. J. Food                                                               decreased significantly at 20°C, and
Microbiol. 101:227-236.                                                                          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.               Bovine manure and bovine manure                  The pathogen was detected on lettuce,
Williams, P.D. Millner, and L.R.                compost inoculated with S. Newport               strawberry, and carrot within 1, 7 and 1
Beuchat. 2006. Migration of                     (8.6 log CFU/g) were separately placed           day, respectively, when initially present
Caenorhabditis elegans to manure and            in the bottom of a glass jar and covered         in bovine manure compost (detection by
manure compost and potential for                with a layer of soil (5 cm) inoculated           enrichment only, no attempts at
transport of Salmonella newport to              (50 worms/g) or not inoculated with C.           enumeration)
fruits and vegetables. Int. J. Food             elegans. A piece of lettuce, strawberry,
Microbiol. 106:61-68.                           or carrot was placed on top of the soil
                                                before jars were sealed and held at 20°C
                                                for up to 10 days.
Kopanic, R.J., Jr., B.W. Sheldon, and           2 ml of a S. typhimurium culture (~ 7-8          American and Oriental cockroaches
C.G. Wright. 1994. Cockroaches as               log CFU/ml) was inoculated onto five             were contaminated twice as often as
vectors of Salmonella: Laboratory               food pellets and then 20 cockroaches             German cockroaches. Cross-
and field trials. J. Food Prot. 57:125-         placed with these pellets in an                  contamination between infected and
132.                                            environmental chamber. After 24, 48,             non-infected cockroaches was most
                                                72, and 96 h, cockroaches were                   frequent within 24 h of contamination
                                                individually sampled.                            event.




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Natural and Experimental Enteric Pathogen Contamination of Insects
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Reference                                       Expt. Details                                    Results
Mumcuoglu, K.Y., J. Miller, M.                  15-25 sterile maggots were transferred           Preliminary studies using a vital dye
Mumcuoglu, M. Friger, and M.                    to a piece of gauze and fed for 2-15 h on        showed that food ingested by the
Tarshis. 2001. Destruction of bacteria          5 ml of brain heart broth containing 108         maggots passed through their intestine
in the digestive tract of the maggot of         – 1010 gfp-labeled E. coli/ml. The               within 1-1.5 h. It was shown that 66.7%
Lucilia sericata (Diptera:                      maggots were viewed with a laser                 of the crops, 52.8% of the midgets,
Calliphoridae). J. Med. Entomol.                scanning confocal microscope.                    55.6% of the anterior hindguts, and
38:161-166.                                                                                      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.              House flies were immobilized and force           Findings show that genes encoding
Waldor, and E. Walker. 2006.                    fed suspensions of defined, donor                antibiotic resistance or toxins will
Horizontal transfer of Shiga toxin and          strains of E. coli containing                    transfer horizontally among bacteria in
antibiotic resistance genes among               chloramphenicol resistance genes on a            the house fly gut via plasmid transfer or
Escherichia coli strains in house fly           plasmid, or lysogenic bacteriophage-             phage transduction.
(Diptera: Muscidae) gut. J. Med.                born Shiga toxin gene stx1. Recipient
Entomol. 43:288-295.                            strains were E. coli lacking these mobile
                                                elements and genes but having
                                                rifampicin as a selectable marker.
Sasaki, T., M. Kobayashi, and N.                House flies (adult, 6-8 old) fed on              The number of E. coli O157:H7 in an
Agui. 2000. Epidemiological potential           tryptic soy broth containing ~ 109               excreted droplet was ~ 104 1 h after
of excretion and regurgitation by               CFU/ml E. coli O157:H7 for 30 min.               bacterial feeding, > 1.8 x 105 3 h after
Musca domestica (Diptera: Muscidae)                                                              feeding, and then drastically decreased
in the dissemination of Escherichia                                                              after 24 h. E. coli O157:H7 persisted in
coli O157:H7 to food. J. Med.                                                                    the crop of house flies for at least 4
Entomol. 37:945-949.                                                                             days.
Sela, S., D. Nestel, R. Pinto, E.               Adult flies (ca. 2 d old) were exposed to        Flies exposed to fecal material enriched
Nemny-Lavy, and M. Bar-Joseph.                  a 20% sucrose solution containing 6-9            with GFP-tagged E. coli were
2005. Mediterranean fruit fly as a              log CFU/ml of E. coli.                           contaminated and were capable of
potential vector of bacterial                                                                    transmitting E. coli to intact apples in a
pathogens. Appl. Environ. Microbiol.                                                             cage model system. Flies inoculated
71:4052-4056.                                                                                    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.                 Slugs were inoculated by placement in a          Viable E. coli was detected on the slug
Ogden, M.J. Wilson, and N.J.C.                  petri dish with 5 ml of a nalidixic acid-        surface for up to 14 days. Slugs that
Strachan. 2006. Slugs: Potential novel          resistant E. coli suspension (5.8-6.0 x          had been fed E. coli shed viable bacteria
vectors of Escherichia coli O157.               109 CFU/ml) and survival on slug                 in their feces with numbers showing a
Appl. Environ. Microbiol. 72:144-149.           surface and feces was measured.                  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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Natural and Experimental Enteric Pathogen Contamination of Insects
(last updated 9/21/2011)


Reference                                       Expt. Details                                    Results
Strother, K.O., C.Dayton Steelman,              Adult and larval beetles were swabbed            C. jejuni was detected on the exterior of
and E.E. Gbur. 2005. Reservoir                  with C. jejuni (9 log CFU/ml) and                larval beetles for up to 12 h.
competence of lesser mealworm                   survival determined for up to 72 h.              C. jejuni was detected in the interior of
(Coleoptera: Tenebrionidae) for                 Adult and larval beetles drank from a            larvae for 72 h and from the feces of
Campylobacter jejuni                            solution containing C. jejuni (9 log             larvae for 12 h after exposure.
(Campylobacterales:                             CFU/ml) and duration of internal                 90% of the birds that consumed a single
Campylobacteraeae). J. Med.                     carriage and fecal shedding determined           adult or larval beetle became
Entomol. 42:42-47                               for up to 144 h.                                 Campylobacter-positive, whereas 100%
                                                3-d-old chickens fed either 1 or 10              of the birds that consumed 10 adults or
                                                infected beetles and cloacal swabs tested        larvae became positive.
                                                periodically for Campylobacter.
Templeton, J.M., A.J. De Jong, P.J.             Beetles were either sprayed with a               45% of 20 of spray-inoculated beetles
Blackall, and J.K. Miflin. 2006.                Campylobacter culture (2.6 x 108                 were still positive after 72 h but only
Survival of Campylobacter spp. in               CFU/ml) or allowed to feed for 24 h on           5.6% of 18 beetles were positive after
darkling beetles (Alphitobius                   an apple (soaked in the Campylobacter            96 h.
diaperinus) and their larvae in                 culture for 20 min). Beetles were tested         14% of 20 feed-inoculated beetles were
Australia. Appl. Environ. Microbiol.            every 24 h for Campylobacter by direct           positive after 48 h but were all negative
72:7909-7911.                                   culture and enrichment.                          at later time points.




Compiled by Marilyn Erickson, Center for Food Safety, University of Georgia                                                          Page 7
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