• Biomedical Science Letters
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• v.3 no.2
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• pp.77-82
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• 1997

One of the most important prerequisites of the industrial microorganism is that it should not be virulent to humans or economically important animals or plants. In this investigation, the microbiological characterization of T. madida N-5-3 strain was performed. And then, the virulence of the test strain in mouse model was examined systematically. The microbiological characteristics of the test strain were found to be fully consistent with those of typical T. madida. The i.p. lethal dose(LD)$_{50}$ of the test strain was greater than 1$\times$10$^8$, because there was no dead animal with the challenge doses upto the level of 1$\times$10$^8$. When 1$\times$10$^8$ yeast cells were challenged to the laboratory mice, T. madida N-5-3 strain was completely cleared from the liver and spleen in 4 days after challenge. And no pathological changes in the histological examination of the internal organs from challenged mice was observed. Above results can provide the predictability of the safety of T. madida N-5-3 strain for the industrial use in the view point of the public health aspect.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.341-350
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• 2009

The research work was carried out to study the pathogenesis covering the clinical signs, gross and histopathological lesions in different organs, and reisolation and identification of the organisms after experimental infection with the local isolate of Salmonella enterica serovar. enterica subspecies (S.) Pullorum at different time interval of the experiment during the period February 2006 to December 2006. One hundred pullets (seronegative to S. Pullorum of 12 weeks age were purchased and divided into 5 (A, B, C, D and E) groups and each group consisted of 20 birds. Four groups (A, B, C and D) were infected orally with a dose of $10^6\;CFU$, $10^7\;CFU$, $2{\times}10^7\;CFU$, $10^8\;CFU$ of S. Pullorum, respectively, and one group (E) was treated as uninfected control. The used methods were necropsy and histopathology, culture of bacteria, staining and biochemical test of Salmonella. Five birds from each group were randomly selected and sacrificed $1^{st}$ week, $2^{nd}$, $3^{rd}$ and $4^{th}$ weeks of post infection (PI). From all the groups, the bacteriological samples (crop, liver, lung, heart, spleen, bile duodenum, ceca and blood) were collected with pre enriched in buffered peptone water in sterile poly bags. Liver, lungs, heart, spleen, intestine, etc. were collected in 10% buffered-formalin for histopathological examination. No clinical signs, gross and histopathological lesions were found in control group and no S. Pullorum was reisolated. Clinical sign of experimentally infected with S. Pullorum in pullets were loss of appetite (100%), slight depression (75%), ruffled feathers (85%), diarrhea (60%) and loss of weight (100%) in chickens. The feed intake and body weight at different weeks after PI differed significantly (p<0.01) among the groups. Grossly, the highest recorded lesion was button-like ulcer in the ceca (80%) and the lowest was white nodules in lungs (1.25%). S. Pullorum were reisolated from crop (91.25%), liver (91.25%), lung (83.75%), heart (71.25%), spleen (87.75%), bile (33.25%), duodenum (92.50%), ceca (97.50%) and from different group of infection (61.25%). The highest microscopic findings were intestinal and cecal mucosa and submucosa exhibited infiltration of mononuclear cells and congestion (96.25%), and the lowest finding was nodule formation in the lungs (3.75%). The pattern of the disease production by local isolate of S. Pullorum in Bangladesh is almost similar with other isolates in different countries.

• Tuberculosis and Respiratory Diseases
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• v.57 no.2
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• pp.138-142
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• 2004

Background : To evaluate exudative pleural fluid, thoracentesis for microbiological and cytological examination and pleural biopsy by using a Cope needle are traditionally performed. Even after these studies, about 20% of patients remain undiagnosed. We evaluated the diagnostic accuracy and complications of 2-mm minithoracoscopy instead of blind biopsy in patients with undiagnosed exudative pleural effusion. Method : Fifteen patients with exudative pleural effusion underwent thoracoscopy between April 2002 and August 2003. The indication was undiagnosed pleural effusions after having performed sputum and pleural fluid exami-nations both microbiologically and cytologically. Results : The median age of the patients was 56 years (range 21-77). Pleural effusions were lymphocyte-dominant in 11 patients (73.3%) and neutrophil-dominant in 3 (20.0%). The remaining patient (6.7%) had pleural-fluid eosinophilia. Minithoracoscopic biopsy revealed accurate diagnosis in 14 patients (93.3%), consisting of tuberculous pleurisy in 8 (66.7%), malignant effusions in 4 (33.3%), and parapneumonic effusions in 2 (13.3%). One was diagnosed as having paragonimiasis from thoracoscopic findings and clinical considerations. There was no procedure-associated mortality. There were six cases of new onset fever (40%) and one of pneumothorax (6.7 %). Conclusion : Two-millimeter minithoracoscopy, which is less invasive than conventional thoracoscopy, was an accurate and safe method for undiagnosed exudative pleural effusion.

• The Journal of the Korean Society for Microbiology
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• v.7 no.1
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• pp.29-41
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• 1972

To grow Myocbacterium leprae in cultured mouse peritoneal macrophages, studies were made with trypsin-purified Myco. laprae on 1) the dynamics of infection of mouse peritonal macrophages in vivo with Myco. leprae by intraperitoneal inoculation, 2) growth experiment of Myco. leprae in cultured mouse peritoneal macrophages by in vivo infection and in vitro cultivation and 3) the observation of pathological changes in spleens of mice induced by intraperitoneal inoculation of Myco. leprae. Results are summarized as follows; 1. Continuing and significant decreases were observed in the numbers of both acid-fast bacilli in cultured macrophage and of macrophages harboring.acid-fast bacilli by the length of inter vats between the time of intraperitoneal inoculation of Myco. leprae and the time of initiation of macrophage culture. 2. No evidence of multiplication of Myco. leprae in the peritoneal macrophages in vivo was found up to 5 months after intraperitoneal inoculation. 3. With cultures of macrophages made 24 hours and 1 week after intraperitoneal inoculation of Myco. leprae and maintained in vitro up to 2 to 3 months, microscopic examination of the stained preparations of cultured macrophages indicated that an apparent increase in the number of acid-fast bacilli in the macrophages did occur. 4. Quantitative experiment with in vivo infected-in vitro cultured macrophages revealed certain features of increase in the number of total acid-fast bacilli in the cultured macrophages 7 and 9 weeks after initiation of the cultures. 5. Pathological changes in the spleens mice inoculated with Myco. leprae were of mainly degenerative nature in the red pulp. No multiplication of Myco. leprae was observed in the spleens of mice up to 5 months after intraperitoneal inoculation.