Use of PFGE to characterize clonal relationships among Belgian clinical isolates of Listeria monocytogenes.

The Belgian Listeria Reference Centre receives between 30 and 50 human clinical strains of Listeria monocytogenes per year. In general, epidemiological data are absent or incomplete, preventing recognition of episodes of listeriosis. However, data on a clonal relationship between strains can indirectly give an idea of the occurrence of episodes.

Sporadic case of listeriosis associated with the consumption of a Listeria monocytogenes-contaminated 'Camembert' cheese.

Listeria monocytogenes is an intracellular gram-positive organism responsible for severe infections in both humans and animals. Whereas the food-borne transmission of listeriosis was demonstrated in several outbreaks, most cases of listeriosis occur sporadically and are rarely linked with consumption of contaminated foods. In this paper a case of septicaemia with L.

Serotyping and esterase typing for analysis of Listeria monocytogenes populations recovered from foodstuffs and from human patients with listeriosis in Belgium.

Listeria monocytogenes strains isolated in Belgium from different foodstuffs and in sporadic cases of human listeriosis were analyzed. The distribution of serovars differed in each of these populations. The bacteria isolated from cheeses and from human patients with listeriosis were further studied by esterase typing.

[First isolation of Listeria welshimeri in a human].

Listeria welshimeri has been up to now isolated only from the environment and from rare animal sources. This note mentions the first isolation from a human source: a faecal carrier.

The potency of bovine PPD tuberculins in guinea-pigs and in tuberculous cattle.

Potency differences between bovine purified protein derivative tuberculin preparations produced in two different centres and also between preparations produced within these centres, were detected in tuberculous cattle and correlated with potency differences in guinea-pigs. Although assays in groups of guinea-pigs sensitized with either killed Mycobacterium bovis or live BCG identified the weak batches and listed the tuberculins in the same order of potency as the cattle assays, there were nevertheless significant differences between potency estimates according to the mode of sensitization and the preparations compared. The implications for the standardization of tuberculin preparation in general are discussed.