In Vitro Bacteriostatic Effects of Rifampin on<i>Orientia tsutsugamushi</i>

Im, Jae Hyoung; Baek, Ji Hyeon; Lee, Jin Soo; Chung, Moon-Hyun; Lee, Sun Myoung; Kang, Jae Seung

doi:10.3346/jkms.2014.29.2.183

Cited by 11 publications

(9 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another study has noted the migratory capacity of MSC [ 50 ]. MSC enhance axon regeneration not only when delivered to the injured nerve or conduit bridging the nerve gap [ 26 , 39 , 51 ], but also when administered intravenously [ 27 , 30 , 52 ]. The MSC migration potential makes possible their detection at the site of sciatic nerve injury on day 7 post intravenous injection to mice and enhance functional recovery of the sciatic nerve [ 27 ].…”

Section: Cell Types Used In Cell Therapy For Nerve Regenerationmentioning

confidence: 99%

Injured Nerve Regeneration using Cell-Based Therapies: Current Challenges

2015

Acta Naturae

View full text Add to dashboard Cite

This paper reviews the recent research progress in the past several years on promoting peripheral nerve recovery using stem and progenitory cells. The emphasis is placed on studies aimed at assessing various stem cells capable of expressing neurotrophic and growth factors and surviving after implantation in the nerve or a conduit. Approaches to improving nerve conduit design are summarized. The contribution of stem cells to axonal regeneration and neural repair is discussed. The side effects associated with cell-based treatment are highlighted. From the studies reviewed, it is concluded that the fate of transplanted stem cells needs further elucidation in a microenvironment-dependent manner.

show abstract

Section: Cell Types Used In Cell Therapy For Nerve Regenerationmentioning

confidence: 99%

Injured Nerve Regeneration using Cell-Based Therapies: Current Challenges

2015

Acta Naturae

View full text Add to dashboard Cite

show abstract

“…CorA was unable to prevent the establishment of latent O. tsutsugamushi infections. Persistence of O. tsutsugamushi after antimicrobial treatment has been observed in all commonly used classes of antimicrobials (28,41). When we induced bacterial reactivation by cyclophosphamide 647 days p.i., viable O. tsutsugamushi organisms from lung homogenates could still be inhibited by CorA concentrations down to the previously determined MIC of 0.0078 g/ml, suggesting that persistence was unrelated to the selection of resistant mutants.…”

Section: Discussionmentioning

confidence: 85%

“…By demonstrating the effectiveness of CorA in vitro and in vivo, our study introduces inhibition of the bacterial RNAP switch region with ␣-pyrone antibiotics as a new and highly potent therapeutic target for treatment of O. tsutsugamushi infections. The rifamycins that also target RNAP, including rifampin, have long been known to be active against O. tsutsugamushi and are favored in areas where poor doxycycline responsiveness has been reported (10,34,41,42). Given the crucial role of rifampin as a first-line bacteriostatic drug in tuberculosis treatment, it was recognized early that rifampin is not an ideal standard regimen for treatment of scrub typhus.…”

Section: Discussionmentioning

confidence: 99%

Orientia tsutsugamushi Is Highly Susceptible to the RNA Polymerase Switch Region Inhibitor Corallopyronin A In Vitro and In Vivo

Kock

Hauptmann

Osterloh

et al. 2018

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Scrub typhus is a potentially lethal infection caused by the obligate intracellular bacterium Reports on the emergence of doxycycline-resistant strains highlight the urgent need to develop novel antiinfectives against scrub typhus. Corallopyronin A (CorA) is a novel α-pyrone compound synthesized by the myxobacterium that was characterized as a noncompetitive inhibitor of the switch region of the bacterial RNA polymerase (RNAP). We investigated the antimicrobial action of CorA against the human-pathogenic Karp strain of and The MIC of CorA against was remarkably low (0.0078 μg/ml), 16-fold lower than that against In the lethal intraperitoneal mouse infection model, a minimum daily dose of 100 μg CorA protected 100% of infected mice. Two days of treatment were sufficient to confer protection. In contrast to BALB/c mice, SCID mice succumbed to the infection despite treatment with CorA or tetracycline, suggesting that antimicrobial treatment required synergistic action of the adaptive immune response. Similar to tetracycline, CorA did not prevent latent infection of However, latency was not caused by acquisition of antimicrobial resistance, since reisolated from latently infected BALB/c mice remained fully susceptible to CorA. No mutations were found in the CorA-binding regions of the β and β' RNAP subunit genes and Inhibition of the RNAP switch region of by CorA is therefore a novel and highly potent target for antimicrobial therapy for scrub typhus.

show abstract

“…These antibiotics have demonstrated high therapeutic efficacies and no cases with relapse; rifampin, in particular, has a bactericidal effect on certain bacteria [ 7 , 8 ]. A previous in vitro experiment, however, indicated that these antibiotics are also bacteriostatic against O. tsutsugamushi [ 9 ]. A combination antibiotic therapy may also be considered for this purpose, although an in vitro experiment revealed that this modality is not more effective than a single antibiotic [ 10 ].…”

Section: Introductionmentioning

confidence: 99%

In vitroSynergism between Chloroquine and Antibiotics againstOrientia tsutsugamushi

Son

Chung

2014

Infect Chemother

Self Cite

View full text Add to dashboard Cite

BackgroundTo investigate whether chloroquine enhances the effect of antibiotics against Orientia tsutsugamushi, the causative organism of scrub typhus, we compared the effect of antibiotics in combination with chloroquine with the effect of antibiotics alone in vitro.Materials and MethodsThe Boryong or AFSC-4 strain was inoculated into ECV304 cells, and incubated in medium containing doxycycline (4 µg/mL), rifampin (4 µg/mL), azithromycin (0.5 µg/mL), chloroquine (1 µg/mL), and each of these antibiotics in combination with chloroquine for 7 d. Immunofluorescence (IF) staining for O. tsutsugamushi was performed 4 hr and 7 d after inoculation of the bacteria, and IF-positive foci were enumerated.ResultsChloroquine inhibited the growth of O. tsutsugamushi by 15.5%. In combination with chloroquine, the antimicrobial effects increased by 4.4% for doxycycline (a 92.9% reduction of bacterial numbers for doxycycline versus a 97.3% reduction for doxycycline plus chloroquine), 4.6% for rifampin (90.0% versus 94.6%), and 8.3% for azithromycin (86.9% versus 95.2%). The antimicrobial effect of the antibiotics alone was significantly different compared to the combined effect of antibiotics and chloroquine (Wilcoxon signed-rank test, P = 0.001).ConclusionsThe combined use of chloroquine with an antibiotic for the treatment of O. tsutsugamushi infections may be useful for increasing the efficacy of the antibiotics.

show abstract

In Vitro Bacteriostatic Effects of Rifampin onOrientia tsutsugamushi

Cited by 11 publications

References 22 publications

Injured Nerve Regeneration using Cell-Based Therapies: Current Challenges

Injured Nerve Regeneration using Cell-Based Therapies: Current Challenges

Orientia tsutsugamushi Is Highly Susceptible to the RNA Polymerase Switch Region Inhibitor Corallopyronin A In Vitro and In Vivo

In vitroSynergism between Chloroquine and Antibiotics againstOrientia tsutsugamushi

Contact Info

Product

Resources

About