A new Salmonella type is described, for which the name Salmonella seremban is proposed; it has the antigenic formula IX, XIII, XII 2, XIIa; i=l, 3, 5. It was the apparent cause of a number of human cases of food poisoning at Seremban, Malaya.
Three species of commonly eaten shellfish found in Malaysian coastal waters were examined for the presence of common bacterial enteropathogens. Vibrio parahaemolyticus, non-agglutinating vibrios, and various serotypes of enteropathogenic E. coli were isolated from a large proportion of them. Salmonella were isolated in two instances. High colony counts with evidence of faecal contamination indicated the strong possibility of pulltion being the cause for the presence of these enteropathogens. Methods of cooking and eating these shellfish enhance their likelihood of acting as vehicles of diarrhoeal disease.
A total of 860 Salmonella isolations were made in Peninsular Malaysia from 15 animal species (domestic and wild), eggs, molluscs, flies, and animal feed. The isolations were distributed among 31 serotypes in eight groups. The most common serotype isolated was Salmonella pullorum, followed by S. choleraesuis and S. infantis. S. typhimurium had the widest zoological distribution. The importance of controlling animal salmonellosis is emphasized.
Salmonella weltevreden has been found to be one of the commonest Salmonella serotypes isolated from diverse sources in India and has also been isolated in a number of other countries. A phage typing scheme was developed for this serotype using a set of six typing phages. These phages had been selected out of 146 phage strains isolated and purified from stool samples of man, laboratory animals and other animals, sewage and surface water sources, and the lytic mutants of temperate phages form S. weltevreden. The phage typing scheme was applied systematically to type the 946 strains from India isolated during 1958-1974 and 148 strains originating from Australia, Burma, England, Gan Island, Holland, Hong Kong, Malaysia, New Zealand, Papua New Guinea, The Philippines, Thailand, The United States and Vietnam during 1953-1971. The scheme was particularly studied to evaluate its utility in mapping the epidemiologically related strains from various sources. The S. weltevreden strains could be classified into ten phage types. Phage types 2 and 7 were found exclusively amongst Indian strains, type 6 from Vietnam and type 8 from Burma, Thailand and Vietnam. Phage types were found to be stable and consistent with the independent epidemiological data available.
Four strains of S. typhi isolated in Malaysia were found to show resistance to chloramphenicol and other antibiotics. In two of these strains it was possible to show that this resistance was transferable.
This problem which is widespread in neighbouring countries and undetected in Malaysia till recently has now been shown to exist in this country. Fears that the incidence of such strains will increase in the future are expressed and the need for vigilance is emphasised.
A survey of lettuce sold in Penang markets showed them to be heavily contaminated with faecal coliforms and nearly half the samples were positive for Salmonella or Shigella. The use of night soil on these vegetables is a likely cause of gastroenteritis.
In August, 1980 a rare serotype S. zanzibar was isolated in the North of Scotland from a man home on leave from Malaysia, whence he returned in November having been bacteriologically negative 2 months previously. In December however, S. zanzibar was isolated from a bulk milk sample taken at a nearby dairy farm. No illness occurred among milking cows which had been brought inside from pasture in mid-October. Since 1972 a variety of different salmonella serotypes had been identified in cattle, milk and other samples at this farm, with seagulls being implicated as the vector transmitting infection from the sewage of a local town on to farmland and an adjacent loch. Although water from this source has not been used in recent years for drinking by cattle, it is utilized for washing floors within the dairy premises. Since 1979, following an outbreak affecting consumers, all milk produced at the farm has been pasteurized.