The development and assessment of a bacteriocin typing method forKlebsiella

Abstract

SUMMARYKlebsiellas are generally typed by the method of capsular serotyping but, although this is a reliable method, it is time consuming, requires the production of a large number of antisera and is not generally available. For this reason another method for typing klebsiellas was sought.A bacteriocin typing method involving mitomycin C induction was developed and the cultural conditions giving optimum klebecin production and the best methods of testing the sensitivity of the organisms to klebecins were determined.Of 190 klebsiella strains screened for bacteriocinogeny, only 68 (35.8 %) produced klebecin and after calculation of similarity values by computer analysis, a typing set of 15 producers was selected. This typing set allowed over 96 % of klebsiella strains to be typed and tests of the reproducibility of the method and the variability of typing patterns in natural populations of klebsiella indicated that results of acceptable accuracy could be obtained, while retaining good discrimination if two or more differences were required between patterns before they were regarded as distinct.A complete set of capsular antisera were prepared, enabling the results obtained from klebecin typing to be compared with those from serotyping. There was generally close agreement between the results from the two typing methods and greater discrimination was obtained between similar strains when the two methods were combined. Klebecin typing and serotyping revealed relationships between strains from five outbreaks of infection, and strains of the same serotype from different hospitals could frequently be distinguished by their klebecin typing patterns.

The assessment and application of a bacteriocin typing scheme forClostridium perfringens

“…The clustering patterns are included for comparison in Table 4. (Edmondson & Cooke, 1979;Hardy, 1982;Simoons-Smit et al 1983). Since only a minority of strains of C. perfringens is bacteriocinogenic, a passive typing method is of more value as long as the variability of typing patterns can be assessed.…”

“…By multiple typing of strains of klebsiella, Edmondson & Cooke (1979) showed that only 670 reproducibility could be expected if patterns differing by one reaction were regarded as distinct. Anderhub et al (1977), studying clinically related strains of Serratia marcescens, found that 520% and 730 of 89 cultures gave identical typing results on two occasions by cross-streaking and mitomycin-induction methods respectively.…”

Diversity of plasmids responsible for multiple resistance in klebsiella serotype K2

“…Gentamicin-resistant klebsiella of serotype K2 were also received from other hospitals both in and out of the London area. Klebecin typing was as described by Edmondson & Cooke (1979) using klebecinproducer and indicator strains provided by Professor E. M. Cooke. Sensitivity testing was as described by Datta et at.…”

A Comparison of the Properties of Klebsiella Strains Isolated From Different Sources

“…The strains that were accepted as klebsiellas had the following characters (see Edmondson and Cooke, 1979): non-motile, acid produced from inositol, hydrogen sulphide not produced (Donovan, 1966), acid produced from adonitol, urea hydrolysed, no ornithine decarboxylase.…”