Cloning and expression of the Campylobacter jejuni glyA gene in Escherichia coli.

Genetic studies of Campylobacter jejuni are greatly hampered by the lack of genetic markers and an established classical gene transfer mechanism between strains of this species. To facilitate future genetic studies and to provide a recombinant DNA approach for analyzing genes of C. jejuni, we constructed an extensive genomic library of a pathogenic C. jejuni strain TGH9011 (serotype 0:3) using pBR322. We report the isolation of a number of recombinant plasmids containing the complete structural gene of glyA, that encodes serine hydroxymethyltransferase (SHMT) of C. jejuni. Escherichia coli cells containing this multicopy recombinant plasmid with the glyA gene produce high levels of SHMT. The SHMT-encoding fragment was identified by subcloning and functional complementation. The expression of the C. jejuni glyA gene was probably via transcription initiated from its own promoter.

The characterization of Vibrio cholerae isolated in Kenya in 1983.

A total of 245 strains of Vibrio cholerae 01 and two strains of V. cholerae non-01 were isolated and collected from diarrhoeal patients in Homa Bay District Hospital and the other medical facilities in Nyanza Province, Kenya in 1983. The majority of V. cholerae 01 tested were Ogawa type (with the exception of nine Inaba type), biotype E1 Tor (except one untypable strain) and Celebes original type (except one cured type). Haemolytic activity to sheep red blood cells was detected in 75.5% of isolates. Out of 245 strains of V. cholerae 01, 184 were resistant to tetracycline, streptomycin and ampicillin. All were sensitive to chloramphenicol and nalidixic acid. Only one strain of V. cholerae 01 was sensitive to all five antimicrobial agents tested. An environmental cholera survey was done after the cholera outbreak subsided. Twenty strains of V. cholerae non-01 were isolated from water samples in Nyanza Province but none of V. cholerae 01 was isolated.

Rotavirus infection of young children in two districts of Kenya from 1982 to 1983 as analyzed by electrophoresis of genomic RNA.

Employing techniques of polyacrylamide gel electrophoresis of viral RNA segments, we studied rotavirus strains and their relative contributions to rotavirus gastroenteritis epidemics in two major districts of Kenya. From early 1982 to the middle of 1983, 18 representative electropherotypes, including 6 short strains, were detected in 30 rotavirus specimens obtained from Nairobi, whereas 16, including 3 short strains, were detected in 70 virus specimens from coastal areas. With the exception of one strain, there were no identical electropherotypes between the two groups of rotaviruses obtained from these different districts. A change in predominant electropherotypes was observed in Mombasa in early 1983, and subsequently, newly occurring strains were detected in a small town along the coast when an apparent increase in gastroenteritis was observed in the district.