[Allele genotype analysis of Plasmodium vivax merozoite surface protein 1 (PvMSP-1) from Dangdong, Liaoning Province].

Nested PCR method was used to amplify the Plasmodium vivax merozoite surface protein 1 (PvMSP-1) gene fragment containing the ICB5 and ICB6 region from Plasmodium vivax in Liaoning Province. The PCR products were digested by Pvu II restriction endonuclease and the digested fragments were observed by 1.5% agarose gel electrophoresis, and all followed by sequencing analysis and comparison. In 11 field isolates of P. vivax, two kinds of DNA fragments with 470 and 400 bp were produced respectively. After PvuII digestion, two Sal-1 type fragments (120 and 350 bp) were obtained from 5 samples of 470 bp. Single band of 400 bp appeared in 1 samples as Belem type. Two bands of 120 and 280 bp appeared from another 1 sample as recombination type III, and other 4 bands with 120 and 240 bp as Korean isolate. The principal types of PvMSP-1 alleles exist in malaria endemic areas in Liaoning Province with no mixed infection of two different type alleles.

[Study on the application and evaluation of methods for gene and antigen detection in plague surveillance program].

OBJECTIVE: To apply and evaluate new methods regarding specific gene and antigen detection in plague surveillance program. METHODS: 1798 samples from natural foci of plague were tested, using internal quality control multiple-polymerase chain reaction, F1 antigen marked by immuno chromatographic assay and enzyme linked immunosorbent assay. Culture of Yersinia pestis and reverse indirect hemagglutination assay were used as reference diagnostic methods. RESULTS: The overall positive rate of culture on Yersinia pestis together with gene and antigen detection was 7.34%, showing an 16.81% increase when comparing to 6.28% using Yersinia pestis culture method alone. The rate of coincidence was 97.13%. CONCLUSION: The new standard being used for specific gene and antigen detection could increase the positive rate of diagnosis on plague.