Comparison of rapid methods for detection of heat-labile (LT) and heat-stable (ST) enterotoxin in Escherichia coli.

Oxoid VET-RPLA, ST-EIA and Pharmacia Phadebact ETEC-LT enterotoxin tests were compared to find a simple but reliable method for detecting enterotoxigenic Escherichia coli (ETEC) in Hungary. In the Oxoid tests, all six reference LT- or ST-producing strains, except one ST-producer, gave positive results. Of 11 reference porcine enterotoxigenic strains, all four LT-producers gave positive reactions for LT but three of 10 ST-producers gave negative reactions for ST. Thirteen of 50 strains from culture collections of H. Steinrück (Germany) were LT+ and nine of 33 were ST+. When 31 isolates were tested simultaneously with the Oxoid and the Pharmacia LT tests, 12 strains were LT+ by the Oxoid LT test but by the Phadebact LT test only seven of these strains were LT+ and, of the remainder, three gave uncertain results and two gave negative results. Of 69 porcine strains, seven were LT+ and three ST+. Of 901 human strains isolated in Hungary, 10 were LT+ and one of 24 tested was ST+. In two cases, ETEC strains were isolated from contacts of travellers returning from Mongolia and Bangladesh. Results of comparative studies with reference strains corresponded well to those of the classical toxin detection tests. The Oxoid test was rapid, sensitive, specific and easy to perform and is recommended for use in screening ETEC isolates.

[Bacteriological studies of the intestinal content of aquatic birds, fishes, and frogs with special reference to the presence of non-cholera vibrios (NCV) (author's transl)]. / Bakteriologische Untersuchungen des Darminhalts von Wasservögeln, Fischen und Fröschen mit besonderer Berücksichtigung des Vorkommens von Nicht-Cholera-Vibrionen (NCV).

In a screening study of surface waters, the authors were successful in culturing NCV in 2/3 of cases. Since these organisms are incapable of multiplication in open waters and yet were present in water samples in considerable amounts, it was postulated that they persisted in certain forms of aquatic life. To elucidate this question, the intestinal contents and in some cases, the bile of a total of 110 animals belonging to 17 different bird, fish, and frog species from different habitata were examined. From these animals, 51.8% were found to be carriers of NCV and 7.3%, of salmonella. Additionally, 4.5-15.5% were found to carry Aeromonas, Plesiomonas, Staphylococcus aureus, and Pseudomonas aeruginosa. Fish and frogs were found to offer NCV organisms possibilities to persist while migratory birds such as stock ducks import them even from tropical areas. When compared with the results of studies performed, salmonella carriers among Danube fish were found to have increased in number.