[Detection of K99 antigen in strains of E coli enteropathogenic for calves (author's transl)].
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Agglutination↗
Biomedical subjects
W H Jansen
Publications and source records attributed to W H Jansen.
Detection of the K99 antigen by means of agglutination and immunoelectrophoresis in Escherichia coli isolates from calves and its correlation with entertoxigenicity.
The common antigen of calf enterotoxigenic strains of Escherichia coli, recently established as the K99 antigen, was studied by means of the slide agglutination test and immunoelectrophoresis. Specific antisera were obtained by absorption of crude antisera with ultrasonicates of autologous cells grown at 18C or by injection into rabbits of the purifies K99 antigen obtained by preparative electrophoresis. The K99 antigen was usually undetectable in calf enterotoxigenic E. coli cultures with capsular K antigens of the A variety grown at 37C on commercially available nutrient agar plates designed for the isolation of Enterobacteriaceae, but was rapidly detectable when grown on a buffered semi-synthetic medium at pH 7.5 (Minca medium). An alternative procedure for the isolation and identification of calf entertosigenic E. coli strains from feces, using the Minca medium, is proposed. K99 was found in 70 of 74 strains of E. coli, the enterotixigenicity of which was established in the ligated gut test in calves. None of the 20 cultures negative in the ligated gut test possessed K99 antigen. The K99 antigen is therefore probably a useful diagnostic tool for the identification of calf enterotixigenic E. coli strains, taking into account that K99 and enterotoxigenicity are controlled by different plasmids.
Agglutination Tests↗
An automatic device for the serotyping of Salmonella.
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Automation↗
Bacteriophage typing of Salmonella typhimurium by use of a mechanized technique.
A new mechanized technique for the application of drops of phages on agar plates is described. Drops of equal size are delivered by needles with the aid of filtered pressurized air. The part of the device which is in contact with phage is interchangeable as a whole.
Bacteriophage Typing↗
New technique for biotyping.
An efficient technique for biotyping, using disposable trays instead of glass tubes and agar instead of liquid media, is described.
Acetates↗
Escherichia coli O antigen typing by means of a mechanized microtechnique.
A mechanized microtechnique for the serological typing of Escherichia coli cultures is described.
Agglutination Tests↗
PCR-mediated DNA typing of Campylobacter jejuni isolated from patients with recurrent infections.
The polymerase chain reaction (PCR) and two primers aiming at the enterobacterial repetitive intergenic consensus (ERIC) and arbitrary DNA sequences, respectively, were used to fingerprint the genomic DNA of 24 Campylobacter jejuni strains isolated from five patients with recurrent C. jejuni infections. Results were compared with biotyping and serotyping. The latter two methods, when combined, distinguished 9 different types, whereas PCR-mediated DNA analysis discriminated 14 different patterns. For six strains, the results of PCR-mediated typing led to different interpretations. This method is proposed as an additional tool to further discriminate between C. jejuni strains that appear related by conventional typing methods. In view of its rapidity and simplicity, this method is a potential candidate to replace the relatively slow and laborious conventional methods. However, further study is needed to assess the sensitivity and specificity of PCR-mediated DNA analysis and to investigate the usefulness of this method as an epidemiological tool in outbreaks of Campylobacter infections.
Bacterial Typing Techniques↗
An unusual H antigen (Z66) in strains of Salmonella typhi.
Eleven Salmonella typhi isolates were recovered from patients with typhoid in Indonesia. These motile isolates had neither H:d nor H:j antigen but had a new H antigen, designated Z66 in this paper. After passage through semi-solid agar medium with anti-Z66 serum (in U-tube), 7 strains were agglutinable by H:d antiserum. No strain was able to express the three H factors. In case of typhoid fever caused by such strains, conventional Widal test may not detect anti-H:d agglutinins in patients' sera.
Antigens, Bacterial↗