Enterobacter sakazakii has been associated with life-threatening infections in premature low-birth-weight infants. Contaminated infant milk formula (IMF) has been implicated in cases of E. sakazakii meningitis. Quick and sensitive methods to detect low-level contamination sporadically present in IMF preparations would positively contribute towards risk reduction across the infant formula food chain. Here we report on the development of a simple method, combining charged separation and growth on selective agar, to detect E. sakazakii in IMF. This protocol can reliably detect 1 to 5 CFU of E. sakazakii in 500 g of IMF in less than 24 h.

This study describes a rapid method for the isolation and detection of Escherichia coli O157:H7 present at low levels (0.04–0.4 cfu/g) in fresh salad produce. Following a short enrichment (5 h at 42C), samples were processed using Pathatrix, a novel recirculating immunomagnetic capture system, linked to real‐time polymerase chain reaction and/or selective agar plating. Processing of post‐enrichment sample aliquots (10 mL diluted 1:25) and the use of preblocked paramagnetic anti‐E. coli O157:H7 beads enhanced target pathogen recovery on selective agar plates in cases where a high microbial load of nontarget microflora was present. This is of particular relevance to the testing of bean sprouts. This method has the potential to provide a result within 7 h. The speed of result offers significant benefits for outbreak investigations and allows the rapid screening of salad produce for E. coli O157:H7 contamination prior to product entering the distribution chain.