An intradermal inoculation model of scrub typhus in Swiss CD-1 mice demonstrates more rapid dissemination of virulent strains of Orientia tsutsugamushi.

Scrub typhus is an important endemic disease of the Asia-Pacific region caused by Orientia tsutsugamushi. To develop an effective vaccine to prevent scrub typhus infection, a better understanding of the initial host-pathogen interaction is needed. The objective of this study was to investigate early...

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Main Authors: Piyanate Sunyakumthorn, Daniel H Paris, Teik-Chye Chan, Margaret Jones, Alison Luce-Fedrow, Suchismita Chattopadhyay, Ju Jiang, Tippawan Anantatat, Gareth D H Turner, Nicholas P J Day, Allen L Richards
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0054570&type=printable
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author Piyanate Sunyakumthorn
Daniel H Paris
Teik-Chye Chan
Margaret Jones
Alison Luce-Fedrow
Suchismita Chattopadhyay
Ju Jiang
Tippawan Anantatat
Gareth D H Turner
Nicholas P J Day
Allen L Richards
author_facet Piyanate Sunyakumthorn
Daniel H Paris
Teik-Chye Chan
Margaret Jones
Alison Luce-Fedrow
Suchismita Chattopadhyay
Ju Jiang
Tippawan Anantatat
Gareth D H Turner
Nicholas P J Day
Allen L Richards
author_sort Piyanate Sunyakumthorn
collection DOAJ
description Scrub typhus is an important endemic disease of the Asia-Pacific region caused by Orientia tsutsugamushi. To develop an effective vaccine to prevent scrub typhus infection, a better understanding of the initial host-pathogen interaction is needed. The objective of this study was to investigate early bacterial dissemination in a CD-1 Swiss outbred mouse model after intradermal injection of O. tsutsugamushi. Three human pathogenic strains of O. tsutsugamushi (Karp, Gilliam, and Woods) were chosen to investigate the early infection characteristics associated with bacterial virulence. Tissue biopsies of the intradermal injection site and draining lymph nodes were examined using histology and immunohistochemistry to characterize bacterial dissemination, and correlated with quantitative real-time PCR for O. tsutsugamushi in blood and tissue from major organs. Soluble adhesion molecules were measured to examine cellular activation in response to infection. No eschar formation was seen at the inoculation site and no clinical disease developed within the 7 day period of observation. However, O. tsutsugamushi was localized at the injection site and in the draining lymph nodes by day 7 post inoculation. Evidence of leukocyte and endothelial activation was present by day 7 with significantly raised levels of sL-selectin, sICAM-1 and sVCAM-1. Infection with the Karp strain was associated with earlier and higher bacterial loads and more extensive dissemination in various tissues than the less pathogenic Gilliam and Woods strains. The bacterial loads of O. tsutsugamushi were highest in the lungs and spleens of mice inoculated with Karp and Gilliam, but not Woods strains. Strains of higher virulence resulted in more rapid systemic infection and dissemination in this model. The CD-1 mouse intradermal inoculation model demonstrates features relevant to early scrub typhus infection in humans, including the development of regional lymphadenopathy, leukocyte activation and distant organ dissemination after low-dose intradermal injection with O. tsutsugamushi.
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spelling doaj-art-e3cf7fb9eb2a4666987050a57850be222025-08-20T03:10:18ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0181e5457010.1371/journal.pone.0054570An intradermal inoculation model of scrub typhus in Swiss CD-1 mice demonstrates more rapid dissemination of virulent strains of Orientia tsutsugamushi.Piyanate SunyakumthornDaniel H ParisTeik-Chye ChanMargaret JonesAlison Luce-FedrowSuchismita ChattopadhyayJu JiangTippawan AnantatatGareth D H TurnerNicholas P J DayAllen L RichardsScrub typhus is an important endemic disease of the Asia-Pacific region caused by Orientia tsutsugamushi. To develop an effective vaccine to prevent scrub typhus infection, a better understanding of the initial host-pathogen interaction is needed. The objective of this study was to investigate early bacterial dissemination in a CD-1 Swiss outbred mouse model after intradermal injection of O. tsutsugamushi. Three human pathogenic strains of O. tsutsugamushi (Karp, Gilliam, and Woods) were chosen to investigate the early infection characteristics associated with bacterial virulence. Tissue biopsies of the intradermal injection site and draining lymph nodes were examined using histology and immunohistochemistry to characterize bacterial dissemination, and correlated with quantitative real-time PCR for O. tsutsugamushi in blood and tissue from major organs. Soluble adhesion molecules were measured to examine cellular activation in response to infection. No eschar formation was seen at the inoculation site and no clinical disease developed within the 7 day period of observation. However, O. tsutsugamushi was localized at the injection site and in the draining lymph nodes by day 7 post inoculation. Evidence of leukocyte and endothelial activation was present by day 7 with significantly raised levels of sL-selectin, sICAM-1 and sVCAM-1. Infection with the Karp strain was associated with earlier and higher bacterial loads and more extensive dissemination in various tissues than the less pathogenic Gilliam and Woods strains. The bacterial loads of O. tsutsugamushi were highest in the lungs and spleens of mice inoculated with Karp and Gilliam, but not Woods strains. Strains of higher virulence resulted in more rapid systemic infection and dissemination in this model. The CD-1 mouse intradermal inoculation model demonstrates features relevant to early scrub typhus infection in humans, including the development of regional lymphadenopathy, leukocyte activation and distant organ dissemination after low-dose intradermal injection with O. tsutsugamushi.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0054570&type=printable
spellingShingle Piyanate Sunyakumthorn
Daniel H Paris
Teik-Chye Chan
Margaret Jones
Alison Luce-Fedrow
Suchismita Chattopadhyay
Ju Jiang
Tippawan Anantatat
Gareth D H Turner
Nicholas P J Day
Allen L Richards
An intradermal inoculation model of scrub typhus in Swiss CD-1 mice demonstrates more rapid dissemination of virulent strains of Orientia tsutsugamushi.
PLoS ONE
title An intradermal inoculation model of scrub typhus in Swiss CD-1 mice demonstrates more rapid dissemination of virulent strains of Orientia tsutsugamushi.
title_full An intradermal inoculation model of scrub typhus in Swiss CD-1 mice demonstrates more rapid dissemination of virulent strains of Orientia tsutsugamushi.
title_fullStr An intradermal inoculation model of scrub typhus in Swiss CD-1 mice demonstrates more rapid dissemination of virulent strains of Orientia tsutsugamushi.
title_full_unstemmed An intradermal inoculation model of scrub typhus in Swiss CD-1 mice demonstrates more rapid dissemination of virulent strains of Orientia tsutsugamushi.
title_short An intradermal inoculation model of scrub typhus in Swiss CD-1 mice demonstrates more rapid dissemination of virulent strains of Orientia tsutsugamushi.
title_sort intradermal inoculation model of scrub typhus in swiss cd 1 mice demonstrates more rapid dissemination of virulent strains of orientia tsutsugamushi
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0054570&type=printable
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