Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.

Outbreaks of foodborne illness attributed to the consumption of Salmonella-tainted cantaloupe have occurred repeatedly, but understanding of the ecology of Salmonella on cantaloupe fruit surfaces is limited. We investigated the interactions between Salmonella enterica Poona, the plant pathogenic bac...

Full description

Bibliographic Details
Main Authors: Dhiraj Gautam, Shefali Dobhal, Mark E Payton, Jacqueline Fletcher, Li Maria Ma
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC4141780?pdf=render
_version_ 1818675904985956352
author Dhiraj Gautam
Shefali Dobhal
Mark E Payton
Jacqueline Fletcher
Li Maria Ma
author_facet Dhiraj Gautam
Shefali Dobhal
Mark E Payton
Jacqueline Fletcher
Li Maria Ma
author_sort Dhiraj Gautam
collection DOAJ
description Outbreaks of foodborne illness attributed to the consumption of Salmonella-tainted cantaloupe have occurred repeatedly, but understanding of the ecology of Salmonella on cantaloupe fruit surfaces is limited. We investigated the interactions between Salmonella enterica Poona, the plant pathogenic bacterium Erwinia tracheiphila, and cantaloupe fruit. Fruit surfaces were inoculated at the natural cracking stage by spreading S. enterica and E. tracheiphila, 20 µl at 107 cfu/ml, independently or together, over a 2×2 cm rind area containing a crack. Microbial and microscopic analyses were performed at 0, 9 and 24 days post inoculation (DPI). Even at 24 DPI (fruit maturity) S. enterica was detected on 14% and 40% of the fruit inoculated with S. enterica alone and the two-pathogen mixture, respectively. However, the population of S. enterica declined gradually after initial inoculation. E. tracheiphila, inoculated alone or together with Salmonella, caused watersoaked lesions on cantaloupe fruit; but we could not conclude in this study that S. enterica survival on the fruit surface was enhanced by the presence of those lesions. Of fruit inoculated with E. tracheiphila alone and sampled at 24 DPI, 61% had watersoaked lesions on the surface. In nearly half of those symptomatic fruits the watersoaking extended into the sub-rind mesocarp, and E. tracheiphila was recovered from that tissue in 50% of the symptomatic fruit. In this work, E. tracheiphila internalized through natural cracks on developing fruits. S. enterica was never detected in the fruit interior (ca. 2-3 mm below rind surface) under the limited conditions of our experiments, but the possibility that it, or other human pathogens that contaminate fresh produce, might also do so should be investigated under a wider range of conditions and produce types.
first_indexed 2024-12-17T08:35:00Z
format Article
id doaj.art-3dcd114333f344cbb32423f5e95580a8
institution Directory Open Access Journal
issn 1932-6203
language English
last_indexed 2024-12-17T08:35:00Z
publishDate 2014-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj.art-3dcd114333f344cbb32423f5e95580a82022-12-21T21:56:30ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0198e10524810.1371/journal.pone.0105248Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.Dhiraj GautamShefali DobhalMark E PaytonJacqueline FletcherLi Maria MaOutbreaks of foodborne illness attributed to the consumption of Salmonella-tainted cantaloupe have occurred repeatedly, but understanding of the ecology of Salmonella on cantaloupe fruit surfaces is limited. We investigated the interactions between Salmonella enterica Poona, the plant pathogenic bacterium Erwinia tracheiphila, and cantaloupe fruit. Fruit surfaces were inoculated at the natural cracking stage by spreading S. enterica and E. tracheiphila, 20 µl at 107 cfu/ml, independently or together, over a 2×2 cm rind area containing a crack. Microbial and microscopic analyses were performed at 0, 9 and 24 days post inoculation (DPI). Even at 24 DPI (fruit maturity) S. enterica was detected on 14% and 40% of the fruit inoculated with S. enterica alone and the two-pathogen mixture, respectively. However, the population of S. enterica declined gradually after initial inoculation. E. tracheiphila, inoculated alone or together with Salmonella, caused watersoaked lesions on cantaloupe fruit; but we could not conclude in this study that S. enterica survival on the fruit surface was enhanced by the presence of those lesions. Of fruit inoculated with E. tracheiphila alone and sampled at 24 DPI, 61% had watersoaked lesions on the surface. In nearly half of those symptomatic fruits the watersoaking extended into the sub-rind mesocarp, and E. tracheiphila was recovered from that tissue in 50% of the symptomatic fruit. In this work, E. tracheiphila internalized through natural cracks on developing fruits. S. enterica was never detected in the fruit interior (ca. 2-3 mm below rind surface) under the limited conditions of our experiments, but the possibility that it, or other human pathogens that contaminate fresh produce, might also do so should be investigated under a wider range of conditions and produce types.http://europepmc.org/articles/PMC4141780?pdf=render
spellingShingle Dhiraj Gautam
Shefali Dobhal
Mark E Payton
Jacqueline Fletcher
Li Maria Ma
Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.
PLoS ONE
title Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.
title_full Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.
title_fullStr Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.
title_full_unstemmed Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.
title_short Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.
title_sort surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits alone or in the presence of the melon wilt pathogen erwinia tracheiphila
url http://europepmc.org/articles/PMC4141780?pdf=render
work_keys_str_mv AT dhirajgautam surfacesurvivalandinternalizationofsalmonellathroughnaturalcracksondevelopingcantaloupefruitsaloneorinthepresenceofthemelonwiltpathogenerwiniatracheiphila
AT shefalidobhal surfacesurvivalandinternalizationofsalmonellathroughnaturalcracksondevelopingcantaloupefruitsaloneorinthepresenceofthemelonwiltpathogenerwiniatracheiphila
AT markepayton surfacesurvivalandinternalizationofsalmonellathroughnaturalcracksondevelopingcantaloupefruitsaloneorinthepresenceofthemelonwiltpathogenerwiniatracheiphila
AT jacquelinefletcher surfacesurvivalandinternalizationofsalmonellathroughnaturalcracksondevelopingcantaloupefruitsaloneorinthepresenceofthemelonwiltpathogenerwiniatracheiphila
AT limariama surfacesurvivalandinternalizationofsalmonellathroughnaturalcracksondevelopingcantaloupefruitsaloneorinthepresenceofthemelonwiltpathogenerwiniatracheiphila