Limits...
Lack of effect of dexamethasone on growth of Orientia tsutsugamushi Gilliam in mouse L929 cells.

Kim CO, Huh AJ, Yeom JS, Lee KS, Chin BS, Han SH, Jeong SJ, Choi JY, Song YG, Kim JM - Yonsei Med. J. (2011)

Bottom Line: Treatment of the cells with dexamethasone at concentrations of 10¹ and 10⁷ pg/mL showed no influence on the growth of Orientia tsutsugamushi.Our results to show that isolated corticosteroid does not enhance the replication of Orientia tsutsugamushi in vitro.Concurrent use of anti-inflammatory or immunosuppressive doses of corticosteroids in conjunction with antibiotics may not have detrimental effects on the course of scrub typhus.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine, Yonsei University College of Medicine, 250 Seongsan-ro, Seodaemun-gu, Seoul 120-752, Korea.

ABSTRACT

Purpose: Previous studies and our own clinical experience suggest that concurrent corticosteroid treatment for severe rickettsial disease with multiorgan failure may improve the clinical course or reduce mortality. However, the use of corticosteroids as adjunctive treatment for rickettsial diseases is controversial. We attempted to determine the influences of corticosteroid on the growth of Orientia tsutsugamushi in vitro to justify and evaluate the clinical applicability of corticosteroid in rickettsial disease.

Materials and methods: L929 cells were infected with Orientia tsutsugamushi Gilliam. Dexamethasone was added to the cells at final concentrations of 10¹ and 10⁷ pg/mL. Cultures were incubated at 35°C and processed for flow cytometry on the 6th day after addition of dexamethasone.

Results: Observation on the 6th day after treatment with dexamethasone in infected cultures revealed that there was no difference in fluorescence intensity among the treatment wells. Treatment of the cells with dexamethasone at concentrations of 10¹ and 10⁷ pg/mL showed no influence on the growth of Orientia tsutsugamushi.

Conclusion: Our results to show that isolated corticosteroid does not enhance the replication of Orientia tsutsugamushi in vitro. Concurrent use of anti-inflammatory or immunosuppressive doses of corticosteroids in conjunction with antibiotics may not have detrimental effects on the course of scrub typhus.

Show MeSH

Related in: MedlinePlus

Morphological changes of L929 cells after steroid treatment (phase contrast microscopy, ×100). L929 cells uninfected with Orientia tsutsugamushi (A), infected L929 cells (B), and L929 cells treated with dexamethason 105 pg/mL (C) after infection were cultured. At 24-hr intervals from 24 hr to 96 hr, gross morphology of L929 cells was examined by phase contrast microscopy.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3104446&req=5

Figure 1: Morphological changes of L929 cells after steroid treatment (phase contrast microscopy, ×100). L929 cells uninfected with Orientia tsutsugamushi (A), infected L929 cells (B), and L929 cells treated with dexamethason 105 pg/mL (C) after infection were cultured. At 24-hr intervals from 24 hr to 96 hr, gross morphology of L929 cells was examined by phase contrast microscopy.

Mentions: Considering the results of previous studies regarding morphological changes of mouse fibroblasts prior to and after Orientia tsutsugamushi infection, uninfected L929 cells, L929 cells infected with Orientia tsutsugamushi, and L929 cells treated with corticosteroids after infection were cultured.10 At 24-hr intervals between 24 and 96 hrs, the gross morphology of the L929 cells was examined by phase contrast microscopy. No differences were detected in the number of cells or morphology according to the status of Orientia tsutsugamushi infection or corticosteroid doses (Fig. 1).


Lack of effect of dexamethasone on growth of Orientia tsutsugamushi Gilliam in mouse L929 cells.

Kim CO, Huh AJ, Yeom JS, Lee KS, Chin BS, Han SH, Jeong SJ, Choi JY, Song YG, Kim JM - Yonsei Med. J. (2011)

Morphological changes of L929 cells after steroid treatment (phase contrast microscopy, ×100). L929 cells uninfected with Orientia tsutsugamushi (A), infected L929 cells (B), and L929 cells treated with dexamethason 105 pg/mL (C) after infection were cultured. At 24-hr intervals from 24 hr to 96 hr, gross morphology of L929 cells was examined by phase contrast microscopy.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3104446&req=5

Figure 1: Morphological changes of L929 cells after steroid treatment (phase contrast microscopy, ×100). L929 cells uninfected with Orientia tsutsugamushi (A), infected L929 cells (B), and L929 cells treated with dexamethason 105 pg/mL (C) after infection were cultured. At 24-hr intervals from 24 hr to 96 hr, gross morphology of L929 cells was examined by phase contrast microscopy.
Mentions: Considering the results of previous studies regarding morphological changes of mouse fibroblasts prior to and after Orientia tsutsugamushi infection, uninfected L929 cells, L929 cells infected with Orientia tsutsugamushi, and L929 cells treated with corticosteroids after infection were cultured.10 At 24-hr intervals between 24 and 96 hrs, the gross morphology of the L929 cells was examined by phase contrast microscopy. No differences were detected in the number of cells or morphology according to the status of Orientia tsutsugamushi infection or corticosteroid doses (Fig. 1).

Bottom Line: Treatment of the cells with dexamethasone at concentrations of 10¹ and 10⁷ pg/mL showed no influence on the growth of Orientia tsutsugamushi.Our results to show that isolated corticosteroid does not enhance the replication of Orientia tsutsugamushi in vitro.Concurrent use of anti-inflammatory or immunosuppressive doses of corticosteroids in conjunction with antibiotics may not have detrimental effects on the course of scrub typhus.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine, Yonsei University College of Medicine, 250 Seongsan-ro, Seodaemun-gu, Seoul 120-752, Korea.

ABSTRACT

Purpose: Previous studies and our own clinical experience suggest that concurrent corticosteroid treatment for severe rickettsial disease with multiorgan failure may improve the clinical course or reduce mortality. However, the use of corticosteroids as adjunctive treatment for rickettsial diseases is controversial. We attempted to determine the influences of corticosteroid on the growth of Orientia tsutsugamushi in vitro to justify and evaluate the clinical applicability of corticosteroid in rickettsial disease.

Materials and methods: L929 cells were infected with Orientia tsutsugamushi Gilliam. Dexamethasone was added to the cells at final concentrations of 10¹ and 10⁷ pg/mL. Cultures were incubated at 35°C and processed for flow cytometry on the 6th day after addition of dexamethasone.

Results: Observation on the 6th day after treatment with dexamethasone in infected cultures revealed that there was no difference in fluorescence intensity among the treatment wells. Treatment of the cells with dexamethasone at concentrations of 10¹ and 10⁷ pg/mL showed no influence on the growth of Orientia tsutsugamushi.

Conclusion: Our results to show that isolated corticosteroid does not enhance the replication of Orientia tsutsugamushi in vitro. Concurrent use of anti-inflammatory or immunosuppressive doses of corticosteroids in conjunction with antibiotics may not have detrimental effects on the course of scrub typhus.

Show MeSH
Related in: MedlinePlus