A Note on the Fate of El Tor Cholera and Other Vibrios in Percolating Filters

Sewage effluent from the anaerobic settling tanks of the Oxfam Sanitation System contained reduced populations of Enterobacteriaceae and small numbers of non-cholera vibrios (NCVs). This effluent was passed through percolating 'filters' constructed either of broken honeycomb bricks or corrugated iron in a zig-zag stack. Multiplication of NCVs occurred in both filter matrices. Laboratory experiments confirmed that NCVs were able to multiply in sewage effluent in static culture and also that Vibrio cholerae El Tor was unable to multiply in this liquor, and died rapidly.     

A proteome reference map for Vibrio cholerae El Tor

A proteome reference map has been constructed for Vibrio cholerae El Tor, in the pI range of 4.0 to 7.0. The map is based on two-dimensional gels (2-D) and the identification, by peptide mass fingerprint, of proteins in 94 spots, corresponding to 80 abundant proteins. Two strains are compared, strain N16961 and a Latin American El Tor strain C3294. The consensus map contains 340 spots consistently seen with both strains grown in Luria-Bertani broth (LB) or minimal M9 medium. The results were obtained from nine gels run with 18 cm immobilized pH gradient strips and precast gels. The 2-D gels were anchored to real N16961 proteins identified by mass spectrometry. Various energy metabolism components and periplasmic ATP-binding cassette (ABC) transporter proteins were identified among the abundant proteins. Two isoforms of OmpU were found. Five operons are proposed and seven hypothetical proteins were experimentally confirmed. Comparisons are made with protein 2-D gels for a classical strain and to microarray analysis available for the N16961 El Tor strain. New results were obtained from the proteome analysis, indicating an abundance of periplasmic ABC transporter proteins not found in microarray studies.     

Biophysical characterization of Vitrio El Tor typing phage e5

Abstract Vibrio cholerae typing phage e5, which can lyse only the El Tor strains of V. cholerae , was characterized. The phage had a polyhedral head 51 nm in diameter and a short tail 13 nm in length. It contained 13 structural polypeptides, with the molecular mass of the major component being 50 kDa. Phage chromosome comprised a 38.5-kb linear double-stranded DNA molecule with unique termini, as determined by restriction fragment analysis and electron microscopy, and had a G+C content of 35.5%. A physical map was constructed with the restriction endonucleases Hae II and Hpa II. Adsorption of the phage to its host followed a biphasic kinetics and its intracellular growth was characterized by a latent period of 15 min and a burst size of 100 particles per infected cell. The phage was found to be moderately thermotolerant.     

Antibiotic sensitivity of El Tor vibrios isolated from open reservoirs

Sensitivity of 500 El Tor vibrio strains isolated from open water reservoirs was studied with respect to 14 antibiotics. Some of the strains markedly differing from the other isolates by the sensitivity levels and the set of the resistance determinants were subjected to a detailed analysis. The problem of distribution of antibiotic resistant strains of the cholera germ is discussed.