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.

A Case of Ulceroglandular Tularemia

Tularemia is a zoonosis caused by Francisella tularensis. It is primarily a disease of wild animals. Human infection is incidental and usually results from interaction with biting or blood-sucking insects, wild or domestic animals, or the environment. An increasing number of cases have been reported in several countries. However, in Korea it has not been reported until now. A 40-year old male patient visited our department on Jan 13, 1997, complaining of multiple swollen lymph-nodes on his axillae and reddish swollen left upper arm which contained an abscess at its central portion for about ten days. On Dec 25, 1996, he found a dead wild rabbit on a nearby mountainside, ate it after cooking it by himself with his hands injured. His abscess was drained and microbiologic examination was done. However no microorganism was isolated. His lymph nodes were surgically removed from both axillae, and we investigated them microbiologically and pathologically. On microbiologic examination, small aerobic gram negative coccobacilli were grown on a chocolate agar plate in an aerobic condition with 5% CO2 at 37 degrees centigrade. On H & E staining, the lymph node showed chronic granulomatous inflammation. We sent the microorganism and lymph nodes to the Centers for Disease Control and Prevention in the United States of America for the definitive diagnosis. Finally the microorganism was identified as F. tularensis by culture morphology, biological tests and immunohistochemical staining. We report the first case of F. tularensis in Korea.

A Case of Ulceroglandular Tularemia Occurred In Korea / 한국역학회지

Tularemia is a zoonosis caused by Francisella tularensis. It is primarily a disease of wild animals. Human infection is incidental and usually results from interaction with biting or blood-sucking insect, wild or domestic animals or the environment. It is common in United States. An increasing number of cases have been reported from the Scandinavian countries, eastern Europe, Siberia, and Japan. But In Korea it has not been reported. A 40-year old male visited the department of Surgery on Jan 13, 1997 complaining multiple swollen lymph-nodes on his axillae and upper right arm for about ten days. On Dec 25, 1996, he found a dead wild rabbit at mountainside nearby, cooked it himself and ate it with his friends. He informed us that he got light injury on both hands while he was walking on the mountainside. On Dec 28, he started to suffer from high fever, fatigue and loss of appetite lasting for a day. After medication at a local clinic for several day, symptoms were somewhat relieved. A week later(Jan 4, 1997), several erythematous lesions developed on his both hands, which left ulcerations on the skin. Both axillary lymph nodes were swollen at both sides, but not tender. He visited the department of surgery on Jan 13 and he admitted on Jan 15. During hospitalization, the lymph nodes were surgically removed from both axillae and upper left arm. On microbiologic examination, small aerobic gram negative coccobacilli were grown on the chocolate agar plate in aerobic condition with 5% CO2 at 37 degrees centigrade. On Feb 10, fine needle aspiration from the liver abscess was done, drawing 3 ml of yellowish thick pustular material, but the microorganism was not isolated at the smear and culture of this material in the same condition as described above. After admission, he was treated with antibiotics(cefazole and marocin). His general conditions and laboratory results, including liver function, were markedly improved. He was discharged on Feb 12 and appears well on subsequent follow-ups. The microorganism and lymph nodes were sent to Centers for Disease Control and Prevention in the United States for further evaluation. A twostep indirect immunoalkaline phosphatase technique using an anti-F. tularensis antibody was performed on the lyph nodes having a positive reaction. The immunohistochemical stain demonstrated intense positivity in the stellate abscesses and fine granular reaction in some of the vessels in the paracortical region. Also F. tularensis was identified in the agar plug by culture morphology and immunofluorescence antibody test. We report a case of F. tularensis in Korea for the first time. Further studies were recommened for epidemiological characteristics and prevention of the disease.