[Identification of microbial subtypes from antibiotic susceptibility data in clinical laboratory for nosocomial infection surveillance].
We developed an algorism to identify microbial subtypes automatically from daily antibiotic susceptibility data in clinical microbiology laboratory. The susceptibility pattern was expressed as a string of digits, each consisting of 0(resistant), 1(intermediate) or 2(susceptible) to respective antibiotics. Any two patterns were regarded identical and combined if the difference at each digit never exceeds 1. The combined pattern was expressed as an array of digit-by-digit weighted averages of the two. The second combination was based on a degree of similarity among the numerical patterns using a formula, which was designed to emphasize differences in highly variable elements. This subgrouping procedure was done every three months. Identity of the detected subtypes between the intervals was determined using the same algorism as for the second combination. The algorism was applied to data of clinical isolates of MRSA, Pseudomonas aeruginosa (PA), Klebsiella pneumoniae (KP), Enterococcus faecalis (EF), Streptococcus pneumoniae (SP), Escherichia coli (EC) that were obtained over a period of 4 years. Three major subtypes of MRSA, KP and EF were consistently detected with shifting mutual frequencies. Most of EC isolates belonged to two consistent subtypes. Although PA and SP had one or two consistent subtypes, there were multiple minor subtypes of varying frequencies. This analysis is regarded as an "infotyping", in contrast to serotype or genotype, of clinical microbial isolates, which is useful for nosocomial infection surveillance.
Sato
K
K
Department of Medical Informatics, Kawasaki University of Medical Welfare, Kurashiki 701-0193.
Ichihara
K
K
Kurokawa
Y
Y
D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification; D002984:Clinical Laboratory Information Systems; D003428:Cross Infection / Q000382:microbiology*; D004352:Drug Resistance, Microbial; D006801:Humans; D008826:Microbial Sensitivity Tests
D000900:Anti-Bacterial Agents