Serodiagnosis and Immunotherapy in Infectious Disease最新文献

The purpose of this study was to explore the antigenic potential of solar-inactivated typhoid antigens and compare them with those produced by acetone treatment. The agglutination titre levels of 1 :512, 1 :256 and 1 :256 were observed with antigens produced by 8 h, 8.5 h and 9 h exposure to the sun, respectively. This was compared with the agglutination titre levels of 1 : 128, 1 : 256 and 1 : 512 produced by 5 : 1 vol/vol, 3 : 1 vol/vol and 2 : 1 vol/vol acetone inactivation respectively. This result showed that high immunogenic, cost effective typhoid antigens can be produced with solar energy. This information can be exploited in future formulation of typhoid vaccine and for serodiagnosis.

Molecular diagnosis of Lyme disease is hindered by genetic variability and, in genes that have a certain degree of stability, by the presence of identical regions in other genera in both related and unrelated species. There are therefore certain limitations in genetic diagnostic techniques and as yet no definitive laboratory diagnostic technique has been discovered.

The serum antibody response against listeriolysin O (LLO) was studied in goats experimentally infected with Listeria monocytogenes, using two sequential oral inoculations at 8 months interval. The serum IgG antibody response against LLO correlated closely with that against the whole bacterium, supporting the role of LLO as the major antigenic determinant of the humoral response against L. monocytogenes. However, only severe listeric infections were accompanied by a distinct anti-LLO antibody response, whereas milder, albeit bacteraemic infections remained only weakly responsive or totally non-responsive. Elevated anti-LLO IgG antibody levels persisted for several months after past infection and even high levels of anti-LLO IgG antibodies without evidence of past or ongoing listeriosis were found. Therefore, in the serodiagnosis of listeriosis, the determination of antiLLO antibody response may be applicable only in severe listeric infections and should always be based on IgG seroconversion.

The immune response of golden hamsters was monitored following experimental infection with Leishmania donovani and subsequent treatment with sodium stibogluconate (Stibanate Sb^v) taking macrophage migration index (MMI), phagocytic activity of peritoneal macrophages, blastogenic response of splenocytes in presence of phytohaemagglutinin (PHA) and specific antibodies to Leishmania antigen, as parameters. MMI, a correlate of macrophage activation and cellular immune response (CMI) decreased to a value of 0.46 ± 0.09 (in infected hamsters) from the normal control value of 1.0 on day 21 post infection (p.i.). The value remained suppressed during the course of observation up to day 54 p.i. in untreated animals. Following stibanate treatment from day 21 p.i. the MMI started rising and was restored to slightly above the normal value (1.20 ± 0.12) on day 54 p.i. The phagocytic activity of peritoneal macrophages using ¹⁴4c leucine labelled Escherichia coli and blastogenic response of splenocytes to PHA did not alter during the infection or after stibanate treatment. The specific humoral response to promastigote antigen as assessed by enzyme-linked immunosorbent assay (ELISA) revealed the appearance of antileishmanial antibodies on day 14 p.i., which gradually reached a peak titre of 1 :3200 on day 34 p.i. On stibanate treatment the antileishmanial antibodies started declining after day 7 post treatment (p.t.) and reached almost normal level on day 28 p.t. These observations strengthen the claim that hamsters can be used as a useful model for the study of the immune response in human visceral leishmaniasis.

The nested polymerase chain reaction (PCR) was clinically investigated to detect the mip gene of Legionella species. PCR detected 20 clinically important Legionella species, such as L. pneumophila, L. micdadei, and L. bozemanii. Eight species of Gram-positive and -negative bacteria other than Legionella species were negative for PCR. The sensitivity of PCR determined by the detection limit of DNA quantity was 1.0 pg for the first PCR, but the sensitivity increased approximately 100-fold to 10 fg following the second PCR. The nested PCR was applied to detect L. pneumophila in the sputum and pleural effusion fluid obtained from a patient with Legionnaires' disease. Both fluids were PCR positive, but culture was negative for L. pneumophila. Our results indicated that the nested PCR may be a useful tool for the rapid detection of L. pneumophila and the clinical diagnosis of Legionnaires' disease.