Cytokine response in Balb/c mice infected with Francisella tularensis LVS and the Pohang isolate

We investigated the immune response induced by the Francisella (F.) tularensis live vaccine strain (LVS) and the Pohang isolate. After the Balb/c mice were infected intradermally (i.d) with 2 x 10(4) cfu of F. tularensis LVS and Pohang, respectively, their blood and organs were collected at different times; 0, 3, 6, 24, 72, 96, 120 and 168 h after infection. Using these samples, RT-PCR and ELISA analysis were carried out for the comparative study of the cytokines, including TNF-alpha, INF-gamma, IL-2, IL-4, IL-10 and IL-12. In the Pohang-infected mice at 120 h, the liver showed a 53 times higher level of TNF-alpha and a 42 times higher level of IFN-gamma than the respective levels at the early time points after infection. The levels of TNF-alpha and IFN-gamma induced by LVS were 5 times lower than those induced by the Pohang isolate. Also, the organs from the Pohang-infected mice showed higher levels of TNF-alpha, IFN-gamma, IL-10 and IL-12 than the levels in the LVS-infected mice. The blood from the Pohang-infected mice at 120 h revealed about a 40 times increased level of IFN-gamma, and IL-10 was also increased by 4 times at 96 h compared to an early infection time point, while IL-4 was not induced during the whole infection period. These results suggest that F. tularensis may induce a Th1-mediated immune response to in vivo infection and the Pohang isolate has a higher capacity than the LVS to induce an acute immune response in Blab/c mice.

Retraction: Usefulness of Eschar PCR for Diagnosis of Scrub Typhus / 감염과화학요법

No abstract available.

Retraction: Usefulness of Eschar PCR for Diagnosis of Scrub Typhus / 감염과화학요법

No abstract available.

Scrub Typhus: A Prospective Study of 76 Cases / 감염과화학요법

BACKGROUND: Orientia tsutsugamushi spreads to the entire body through the blood and lymphatics, and it induces vasculitis that results in the patients manifesting symptoms of systemic organ involvement. MATERIALS AND METHODS: We conducted a prospective study to evaluate the clinical manifestations and the change of the laboratory results after instituting treatment for scrub typhus. RESULTS: Most patients presented with fever (100%), malaise (96.1%) and thirst (96.1%). It was remarkable that most patients presented with severe thirst, except for 3 healthy, young patients. This thirst was persistent even after the resolution of fever. The renal and hepatic dysfunction were reversible after the administration of appropriate antibiotics. For the blood testing, it was deteded that the CRP, and LDH were elevated in most patients (95.9% and 100% respectively). DIC could be diagnosed in 95.5% of the patients at the time of admission CONCLUSION: Most patients presented with fever, malaise and severe thirst, and the renal and hepatic dysfunction were reversible after the administration of appropriate antibiotics. DIC was observed in most of our patients, but hemorrhage and infarction were not present. CRP showed a rapid improvement, nonetheless, the LDH and DIC test results improved slowly.

Usefulness of Eschar PCR for Diagnosis of Scrub Typhus / 감염과화학요법

BACKGROUND: We describe a case of scrub typhus, of which the diagnosis was made by PCR using eschar and serologic diagnosis. The patient's attendant insisted that the eschar like crust lesion was caused by minor trauma. In order to find out whether the crust on his head is eschar or not, PCR using eschar was performed. MATERIALS AND METHODS: Informed consent was taken, and then a piece of crust was taken apart. We immerged the crust with about 1 mL of saline bottle. We performed the nested PCR of gene that encodes the 56-kDa specific protein for O. tsutsugamushi. The first serology test for O. tsutsugamushi using indirect immunofluorescent antibody was performed. Then the second serology test & eschar PCR assay were performed at the second week after treatment. RESULTS: 56-kDa protein specific bands were detected in both buffy coat and eschar sample collected at first day of antibiotic administration. However, in the follow up PCR study 7 days after antibiotics administration, 56-kDa protein specific band was detected at only newly formed eschar, not at buffy coat. CONCLUSION: The eschar PCR assay can be useful diagnostic test, even though patient with scrub typhus underwent appropriate antibiotics therapy. The nested PCR method for eschar might be both rapid diagnostic test for scrub typhus in the early acute stage and differential test whether a crust is eschar or not.

Usefulness of Nested PCR for Diagnosis of Scrub Typhus in Clinical Practice: Prospective study / 감염과화학요법

BACKGROUND: Laboratory studies as diagnostic tools of scrub typhus have shown PCR to be sensitive and specific, but there have been few clinical studies. The aims of this study were to determine the diagnostic accuracy and clinical usefulness of the nested PCR through a prospective comparison of the nested PCR and indirect immunofluorescence assay (IFA). MATERIALS AND METHODS: We conducted a multicenter prospective study of patients with possible scrub typhus. Adult patients who have had fever together with eschar or a maculopapular skin rash and more or equal to two of the following symptoms: headache, malaise, myalgia, coughing, nausea, and abdominal discomfort were enrolled. Each patient was admitted between September, 2004 and December, 2004 to Chosun University Hospital and one of its three community branch hospitals (Haenam General Hospital, Jangheung Hospital, Muan Hospital), which are all located in the southwest of Korea. Whole blood samples were collected for PCR testing and sera were obtained for serology evaluation using the IFA and passive hemagglutination assay (PHA). RESULTS: We enrolled 135 possible scrub typhus patients, and 118 scrub typhus patients were confirmed on the basis of either a single indirect immunofluorescent specific IgM titer against O. tsutsugamushi of > or =1:10 or 4-fold or greater rise in IFA follow up titer. One hundred eighteen patients were confirmed as scrub typhus, 7 patients were undetermined and 10 patients were confirmed as the other diseases. The result of nested PCR assay demonstrated a sensitivity of 82.2% (95% confidence interval 0.74-0.88), a specificity of 100% (95% confidence interval 0.66-1), positive predictive value of 1 (95% confidence interval 0.95-1) and negative predictive value of 0.32 (95% confidence interval 0.17-0.51). 96 patients out of 118 patients were positive for IgM on the admission day. Of 22 patients with negative for IgM antibody at admission, 19 had positive results for nested PCR using buffy coat. CONCLUSION: The nested PCR assay of buffy coat is useful for rapid and reliable test for confirmation of the diagnosis of scrub typhus.

Scrub Typhus: A Prospective Study of 76 Cases / 감염과화학요법

BACKGROUND: Orientia tsutsugamushi spreads to the entire body through the blood and lymphatics, and it induces vasculitis that results in the patients manifesting symptoms of systemic organ involvement. MATERIALS AND METHODS: We conducted a prospective study to evaluate the clinical manifestations and the change of the laboratory results after instituting treatment for scrub typhus. RESULTS: Most patients presented with fever (100%), malaise (96.1%) and thirst (96.1%). It was remarkable that most patients presented with severe thirst, except for 3 healthy, young patients. This thirst was persistent even after the resolution of fever. The renal and hepatic dysfunction were reversible after the administration of appropriate antibiotics. For the blood testing, it was deteded that the CRP, and LDH were elevated in most patients (95.9% and 100% respectively). DIC could be diagnosed in 95.5% of the patients at the time of admission CONCLUSION: Most patients presented with fever, malaise and severe thirst, and the renal and hepatic dysfunction were reversible after the administration of appropriate antibiotics. DIC was observed in most of our patients, but hemorrhage and infarction were not present. CRP showed a rapid improvement, nonetheless, the LDH and DIC test results improved slowly.

Usefulness of Eschar PCR for Diagnosis of Scrub Typhus / 감염과화학요법

BACKGROUND: We describe a case of scrub typhus, of which the diagnosis was made by PCR using eschar and serologic diagnosis. The patient's attendant insisted that the eschar like crust lesion was caused by minor trauma. In order to find out whether the crust on his head is eschar or not, PCR using eschar was performed. MATERIALS AND METHODS: Informed consent was taken, and then a piece of crust was taken apart. We immerged the crust with about 1 mL of saline bottle. We performed the nested PCR of gene that encodes the 56-kDa specific protein for O. tsutsugamushi. The first serology test for O. tsutsugamushi using indirect immunofluorescent antibody was performed. Then the second serology test & eschar PCR assay were performed at the second week after treatment. RESULTS: 56-kDa protein specific bands were detected in both buffy coat and eschar sample collected at first day of antibiotic administration. However, in the follow up PCR study 7 days after antibiotics administration, 56-kDa protein specific band was detected at only newly formed eschar, not at buffy coat. CONCLUSION: The eschar PCR assay can be useful diagnostic test, even though patient with scrub typhus underwent appropriate antibiotics therapy. The nested PCR method for eschar might be both rapid diagnostic test for scrub typhus in the early acute stage and differential test whether a crust is eschar or not.

Usefulness of Nested PCR for Diagnosis of Scrub Typhus in Clinical Practice: Prospective study / 감염과화학요법

BACKGROUND: Laboratory studies as diagnostic tools of scrub typhus have shown PCR to be sensitive and specific, but there have been few clinical studies. The aims of this study were to determine the diagnostic accuracy and clinical usefulness of the nested PCR through a prospective comparison of the nested PCR and indirect immunofluorescence assay (IFA). MATERIALS AND METHODS: We conducted a multicenter prospective study of patients with possible scrub typhus. Adult patients who have had fever together with eschar or a maculopapular skin rash and more or equal to two of the following symptoms: headache, malaise, myalgia, coughing, nausea, and abdominal discomfort were enrolled. Each patient was admitted between September, 2004 and December, 2004 to Chosun University Hospital and one of its three community branch hospitals (Haenam General Hospital, Jangheung Hospital, Muan Hospital), which are all located in the southwest of Korea. Whole blood samples were collected for PCR testing and sera were obtained for serology evaluation using the IFA and passive hemagglutination assay (PHA). RESULTS: We enrolled 135 possible scrub typhus patients, and 118 scrub typhus patients were confirmed on the basis of either a single indirect immunofluorescent specific IgM titer against O. tsutsugamushi of > or =1:10 or 4-fold or greater rise in IFA follow up titer. One hundred eighteen patients were confirmed as scrub typhus, 7 patients were undetermined and 10 patients were confirmed as the other diseases. The result of nested PCR assay demonstrated a sensitivity of 82.2% (95% confidence interval 0.74-0.88), a specificity of 100% (95% confidence interval 0.66-1), positive predictive value of 1 (95% confidence interval 0.95-1) and negative predictive value of 0.32 (95% confidence interval 0.17-0.51). 96 patients out of 118 patients were positive for IgM on the admission day. Of 22 patients with negative for IgM antibody at admission, 19 had positive results for nested PCR using buffy coat. CONCLUSION: The nested PCR assay of buffy coat is useful for rapid and reliable test for confirmation of the diagnosis of scrub typhus.