Occurrence and levels of indicator bacteriophages in bathing waters throughout Europe.

Somatic coliphages, F-specific RNA bacteriophages, bacteriophages infecting Bacteroides fragilis, Escherichia coli and enterococci were counted in bathing waters in the late spring and summer. We tested fresh and marine bathing waters from North, South, East and West Europe expected to contain between 100 and 500 E. coli per 100 ml, although wider ranges were sometimes found. Bacteriophages were counted after concentration, since a preliminary study proved that this step was necessary to obtain positive counts. During monitoring, a first-line quality control with reference materials for bacteria and bacteriophages was performed by all the laboratories participating in the study. The same microbes were also counted in raw sewage samples from various areas in Europe, where the bacterial indicators and the three groups of bacteriophages were detected in roughly the same numbers. All groups of bacteriophages were detected in both fresh and marine bathing waters throughout Europe. Reliable and complete results from 147 samples showed that for log-transformed values, E. coli and bacteriophages were slightly correlated. However, the slope of the regression line changed according to E. coli concentration and the correlation diminished when this concentration was close to zero per 100 ml. The ratios between E. coli and phages in bathing waters differed significantly from those in sewage. The relative amounts of bacteriophages, mainly somatic coliphages and phages infecting Bact. fragilis RYC2056, increased in bathing waters with low E. coli concentration, especially in seawater samples containing < 100 E. coli per 100 ml. The relationship of bacteriophages with respect to enterococci paralleled that of bacteriophages with respect to E. coli. Somatic coliphages and bacteriophages infecting Bact. fragilis are useful to predict the presence of some pathogens with the same origin as present bacterial indicators but with higher survival rates.

Numbers of Salmonella enteritidis in the contents of naturally contaminated hens' eggs.

Over 5700 hens eggs from 15 flocks naturally infected with Salmonella enteritidis were examined individually for the presence of the organism in either egg contents or on shells. Thirty-two eggs (0.6%) were positive in the contents. In the majority, levels of contamination were low. Three eggs, however, were found to contain many thousands of cells. In eggs where it was possible to identify the site of contamination, the albumen was more frequently positive than the yolk. Storage at room temperature had no significant effect on the prevalence of salmonella-positive eggs but those held for more than 21 days were more likely (P less than 0.01) to be heavily contaminated. In batches of eggs where both shells and contents were examined, 1.1% were positive on the former site and 0.9% in the latter.

A rapid and simple method for the detection and enumeration of Escherichia coli in cleansed shellfish.

A multiple-tube technique based on peptone water incubated at 44 degrees C for 24 h followed by detection of indole was found to be sensitive and specific for the detection of Escherichia coli in oysters and mussels. The method has the advantage of providing rapid results and is both less expensive and less time-consuming than other MPN techniques.

Oerskovia species: rare opportunistic pathogens.

The second documented instance of opportunistic infection by member of the genus Oerskovia is reported. There is some evidence to suggest that this group of bacteria, which is extensively distributed in the soil, may be more closely associated with man than has hitherto been supposed.