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Summary. Studies were performed on a cytotoxin (CT) from human strains of Campylobacter jejuni isolated in Malaysia. CT was detected by cytopathic effect (CPE) on HeLa cells at titres from 8 to 32, in culture filtrates from 14 (48%) of 29 human isolates. The CPE correlated well with a quantitative 'lcr-release assay where a specific release of 5 4 6 8 % was noted. CT production was lost after 5-7 subcultures. CT activity was also detected in 5 (26%) of 19 faecal filtrates from which CTproducing isolates were subsequently obtained. The mol. wt of CT was estimated by Sephadex G-50 chromatography to be > 30 000. In a suckling-mouse assay, CT consistently failed to demonstrate fluid accumulation after intragastric inoculation of culture filtrate. The Removable Intestinal Tie Adult Rabbit Diarrhoea (RITARD) assay was also used. Rabbits given CT-producing strains of C. jejuni developed bacteraemia and severe watery mucus-containing diarrhoea for the duration of the experiment with death of some animals. Rabbits given CT non-producing strains had less severe disease and none died. Rabbits given partially-purified CT had diarrhoea for 3 days but none died.

173 isolat S. typhi yang telah diidentifikasi tlengan PCR dil,ji lebih lanjr.rt untuk ,nengetahrd profil antibiogram, MIC, profil plasmid serta analisis Pulsed-Field Gel Electrophoresis (PFGE). 36Vo (63) dari isolat tersebut resisten terhadap satu atau lebih antibiotika. Dari persenlase tersebut, 207o (35) resisten lerhadap khloranfenikol (C) dan trimetoprim sutfametol

No abstract

AbstrakKami telnh menyusun suatu pustaka gen target dan pustaka epitop/peptida acak yang terdapat di permukaan filnmen partikel faga. Pustaka target gen dibuat dengan teknik kloning dan ekspresi fragmen-fragmen DNA S. typhi yang retntif pendek ( 100-300 pb) dengan menggabungkan dengan gen permukaan faga pIII. Dengan menggunakan biopanning assay dl mana serum dari penderita demam tifuid yang telah diencerkan diimobilisasi pada suatufase padat (misalnya pada pelat ELISA atau butir magnetik), epitop antigenik dari pustaka ini dapat diidentifikasi melalui pengikntan dan selnnjutnya elusi dari faga rekombinan tersebut, serta pembacaan sekuens DNA yang relevan. Sekuens DNA yang berhasil dii.dentffikasi telnh dihimpun dalam suatu data dasar dan beberapa epitop antigenik telah diidenffikasi. Kelebihan pendekatan ini adaLah pada kemampuannya untuk menemukan seluruh spektrum epitop yang antigenik dan mampu pukt menilai reaksi tanggap kebal dari penderita terhadap galur S. Typhi yang spesifik. Penemuan tersebut di atas dapat memberi impliknsi sangat penting dalam meningkntkan pemahaman akan patogenesis penyakit, cliagnosis yang Lebih baik dan pengembangan vaksin di masa depan. AbstractWe have constructed a genome-targeted library o/Salmonella typhi displayed on the surface of filamentous phage particles. Tlrc getxome-targeted library was made by cloning and expressing relatively short DNAfragments (100-300bp) from S. typhi genomic DNA into the pIII phage coat protein genes of a phagemid. Utilizing a biopanning assay, where diluted serafrom patients with typhoitl fever were immobilised on a solid support (paramagnetic beads), aniigenic epitopes from the genome-targeted phage libraryt were identifi.ed following binding and subsequent elution of recombinant phages ancl DNA sequencing of relevant inserts. Database searching of the identffied sequence was carried out and putative ontigenic epitopes identified, The power of this approach lies irr its abit.ity to ,"nrrh yo, the entire spectrum of antigenic epitopes and in assessing individual patientk immune responses to particuldr strains of S. typhi. The findings may have important implications for improved understanding of disease pathogenesis, better diagnostics ancl future development of vaccines.