Biochemical and serological investigations on clinical isolates of klebsiella

Abstract

SUMMARYA series of 925 clinical isolates of klebsiella was examined by serological and biochemical typing. To perform serological typing (capsular swelling) 77 capsular antisera were prepared, tested against the type strains and grouped in 13 pools. With this serotyping method 800 ofthe cultures were typable and 63 distinct types could be recognized.All strains were typable biochemically by means of the numerical coding system of the API-20E system supplemented by digits derived from 15 additional conventional biochemical tests. With the API-20E system 24 different biotypes could be distinguished whereas the combination of API-20E and the 15 additional tests produced 93 biotypes. Maximum discrimination of strains was achieved by the combination of serological and biochemical typing (256 bioserotypes). The reproducibility, typability and discriminating power of the biotyping system was not inferior to serotyping. For epidemiological purposes biotyping can replace serotyping of Klebsiella species, especially in laboratories less well equipped.

Molecular Serotyping ofKlebsiellaSpecies Isolates by Restriction of the Amplified Capsular Antigen Gene Cluster

“…This rate of nontypeable strains is lower than that obtained by classical K serotyping, which ranges from 8 to 23% (4,12,24,37). Unsuccessful PCR amplifications can probably be attributed to sequence variation at the gnd primer-annealing site.…”

“…Therefore, in several cases it is necessary for individual sera to be absorbed with the crossreacting K antigens for diagnostic use. In addition, a substantial proportion, ranging from 8 to 23%, of Klebsiella strains are nontypeable (12,24,37), either because they harbor K antigens that have not been incorporated in the reference collection or because they are noncapsulated. Serotyping is not easy to perform, and interpretation of the results is subjective.…”

Comparison of biochemical and serological typing results and antimicrobial susceptibility patterns in the epidemiological investigation of Klebsiella spp

“…from 434 patients were available for this study (Simoons-Smit et al 1985 In the NICU, specimens had been taken from ear, nose, umbilicus and rectum of each baby on admission. Thereafter, specimens had been taken if there was an indication of infection at any particular site; in periods in which many gentamicinresistant klebsiella isolates had been cultured the admission cultures had been repeated weekly for each baby.…”

“…The biotyping, based on 35 biochemical reactions, and the serotyping of these strains have been described previously (Simoons-Smit et al 1985). Sensitivity to antibiotics was tested at the time of isolation by disk diffusion tests (AB Biodiscs, Sweden).…”

Evaluation of the stability of biochemical phenotypes of Escherichia coli upon subculturing and storage

“…Extensive studies of the biochemical reactions of bacteria have been done to introduce biochemical typing systems in epidemiological studies of bacteria (Barr & Hogg, 1979;Krishnan et al, 1987;Crichton & Old, 1982). To achieve maximum discrimination, biotyping together with serotyping (Simoons-Smit et al, 1985 ;van der Waaij et al, 1976), serotyping and phage typing (Rennie et al, 1978), serotyping and fimbriation analysis (Brauner et al, 1987), serotyping and outer-membrane protein (OMP) analysis (Stenderup & 0rskov, 1983 ;Achtman et al, 1983) or sero/OMP/electrophoretic analysis of alloenzymes (Ochman & Selander, 1984) have been suggested for the study of epidemiologically important bacterial clones. The value of biotyping in combination with the other bacterial properties used in Abbreviations: EPEC, enteropathogenic Escherichia coli; F, deepfrozen, N, non-subcultured and s, subcultured strains; OMP, outermembrane protein.…”