
Full text loading...
Category: Applied and Industrial Microbiology
Isolation and Identification of Enterobacter sakazakii, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555815608/9781555814601_Chap02-1.gif /docserver/preview/fulltext/10.1128/9781555815608/9781555814601_Chap02-2.gifAbstract:
Due to the association of Enterobacter sakazakii with neonatal infections, the organism has primarily been associated with powdered infant formula. However, E. sakazakii is widely distributed in the environment and in foods, with the most probable sources of the organism being water, soil, and vegetables. It is important that E. sakazakii infection from rehydrated infant formula can arise from contaminated water, introduction by the caregiver, or the environment. In addition to specific criteria for E. sakazakii, the replacement of the original indicator organism group, coliforms with Enterobacteriaceae, has been proposed. The Food and Drug Administration (FDA)-approved method is a presumptive, most-probable-number test based on the three-tube enrichment format, so that low levels of the organism, if present in the product, can be detected and quantified. A chromogenic agar was developed, designated Druggan-Forsythe-Iversen (DFI) agar, where a chromogenic substrate, 5-bromo-4-chloro-3- indolyl-α-D-glucopyranoside, is used as an indicator of α-glucosidase activity. Rapid development of laboratory detection and recognition methods for infectious agents has been aided by the rapid and innovative developments in nucleic acid amplification technologies. Molecular subtyping of bacteria by profiling either proteins or nucleic acids is a useful approach to investigate the epidemiological relationship(s) of isolates involved in outbreaks of food-borne disease. A multilocus sequence typing method using 10 housekeeping genes is presently under development for E. sakazakii and looks very promising as a molecular typing tool for the epidemiology of E. sakazakii.
Full text loading...
Conventional cultural detection of E. sakazakii (from Forsythe, 2005 ).
XbaI-generated PFGE profiles for a collection of E. sakazakii isolates.
ERIC-PCR DNA profiles for a collection of E. sakazakii isolates and a Pantoea agglomerans strain.
Sources of E. sakazakii a
Summary of Enterobacteriaceae cultured from different infant formulations a
Surveys of powdered infant formula or milk powders for E. sakazakii
General microbial flora cultured from powdered infant formula a
Proposed CCFH and ICMSF microbiological criteria a
Presence of E. sakazakii in samples in which Enterobacteriaceae were present in or absent from powdered infant formula samples
Culture methods for the detection of E. sakazakii in powdered infant formula
Composition of E. sakazakii enrichment broths
Composition of selective and differential agars for E. sakazakii
Percentage of strains showing increase in optical density after 24 h of incubation in enrichment media a
Percent growth of E. sakazakii strains and other Enterobacteriaceae on various selective and differential agars a
Comparison of sensitivity and specificity of the FDA method with ISO (DTS 22964) for the isolation of E. sakazakii a
Sensitivity and specificity of three biochemical profiling methods a
E. sakazakii biotypes and 16S rRNA gene sequence cluster groups a
PCR primers and their thermodynamic characteristics, genome targets, and sequences used for the detection of E. sakazakii