Journal of clinical microbiology
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J. Clin. Microbiol. · Dec 1993
Molecular epidemiology of Escherichia coli O157:H7 strains by bacteriophage lambda restriction fragment length polymorphism analysis: application to a multistate foodborne outbreak and a day-care center cluster.
Genomic DNAs prepared from 168 isolates of Escherichia coli O157:H7 were analyzed for restriction fragment length polymorphisms on Southern blots probed with bacteriophage lambda DNA. The isolates analyzed included strains from a recent large multistate outbreak of E. coli O157:H7 infection associated with consumption of poorly cooked beef in restaurants, a day-care center cluster, and temporally and geographically unrelated isolates. ⋯ E. coli O157:H7 from 42 patients temporally or geographically unrelated to either cluster of infection possessed unique and different lambda restriction fragment length patterns, except for paired isolates from three separate clusters of infection. These data demonstrate that the hybridization of DNA digests of E. coli O157:H7 with radiolabelled bacteriophage lambda DNA can be a useful, stable, and discriminatory epidemiologic tool for analyzing the linkage between strains of E. coli O157:H7.
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J. Clin. Microbiol. · Dec 1993
Comparative StudyIsolation of Mycobacterium avium complex from water in the United States, Finland, Zaire, and Kenya.
Disseminated infection with organisms of the Mycobacterium avium complex (MAC) is a common complication of AIDS in the United States and other developing countries, but it is rare or absent in sub-Saharan Africa. To assess the comparative likelihood of exposure to MAC in these geographic areas, we used a standard protocol to culture 91 water samples from environmental sites and piped water supply systems in the United States, Finland, Zaire, and Kenya. MAC was isolated from all geographic areas and from 22 of 91 (24%) samples. ⋯ Serovar determinations showed that six of eight isolates from the United States were serovar 4 or 8. One MAC isolate from Zaire was identified as an "X" mycobacterium. These data suggest that exposure to MAC in water is likely in diverse areas of the world, but that the likelihood of human exposure to the organism in water may be slightly less in sub-Saharan Africa than in developed countries in the Northern Hemisphere.