Survival of Enterobacter sakazakii in a Dehydrated Powdered Infant Formula

Edelson-Mammel, Sharon G.; Porteous, Mary K.; Buchanan, Robert L.

doi:10.4315/0362-028x-68.9.1900

Cited by 107 publications

(46 citation statements)

References 15 publications

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“…were detected in 29% (12/42) of PIF samples, yet none were >2 MPN/100 g (table 1, 2). Edelson-Mammel et al [36] also reported that the concentration of Cronobacter present in US manufactured PIF was frequently below 1 MPN/100 g, corroborating the results of the present study. In Japan, Oonaka et al [37] analyzed a total of 149 samples, of which 61 were of domestic production and 88 imported samples.…”

Section: Resultssupporting

confidence: 82%

Screening for Cronobacter Species in Powdered and Reconstituted Infant Formulas and from Equipment Used in Formula Preparation in Maternity Hospitals

Santos¹,

Silva

Junqueira

et al. 2013

Ann Nutr Metab

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Background/Aims:Cronobacter spp. have been identified as being of considerable risk to neonates. The occurrence of organisms in infant formulas is therefore of considerable interest. Methods: The occurrence of Cronobacter spp. in infant feeds (formulas and fortified cow's milk) was determined using most probable number (MPN) analysis, and from formula preparation utensils. Ninety-nine samples were analyzed, of which 42 were unopened cans of powdered infant formula (PIF), 25 reconstituted infant formulas in feeding bottles, 27 utensils used in the preparation of infant formula and 5 samples of fortified cow's milk. Presumptive Cronobacter spp. isolates were identified using the 7 allele multilocus sequence typing (MLST) scheme. Results: C. sakazakii, C. malonaticus and C. muytjensii were recovered from PIF. Although the incidence of Cronobacter in PIF was 29% (12/42), the level was low with an average of 0.54 MPN/100 g. According to MLST profiling, C. sakazakii was the most frequently isolated Cronobacter species, and C. sakazakii ST4 (associated with neonatal meningitis) was recovered from 2/42 PIF samples at 0.51 and 0.92 MPN/100 g. Conclusions:Cronobacter spp. can be isolated from PIF and therefore strict hygienic practices during PIF preparation are important to minimize neonate exposure and reduce the risk of severe infections.

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Section: Resultssupporting

confidence: 82%

Screening for Cronobacter Species in Powdered and Reconstituted Infant Formulas and from Equipment Used in Formula Preparation in Maternity Hospitals

Santos¹,

Silva

Junqueira

et al. 2013

Ann Nutr Metab

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“…Initial populations decreased by 2 log units immediately following desiccation and by an additional 4 log units during storage for 6 months at an unspecified temperature. Desiccation of cells used in our study and in the study reported by Edelson-Mammel and Buchanan (11) in powdered infant formula caused the death of fewer cells than reported in BHI cultures by Breeuwer et al (4).…”

Section: Vol 71 2005 Performance Of Media For Recovery Of E Sakazamentioning

confidence: 50%

Performance of Media for Recovering Stressed Cells of Enterobacter sakazakii as Determined Using Spiral Plating and Ecometric Techniques

Gurtler

Beuchat

2005

Appl Environ Microbiol

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A study was done to determine the performance of differential, selective media for supporting resuscitation and colony development by stressed cells of Enterobacter sakazakii. Cells of four strains of E. sakazakii isolated from powdered infant formula were exposed to five stress conditions: heat (55°C for 5 min), freezing (؊20°C for 24 h, thawed, frozen again at ؊20°C for 2 h, thawed), acidic pH (3.54), alkaline pH (11.25), and desiccation in powdered infant formula (water activity, 0.25; 21°C for 31 days). Control and stressed cells were spiral plated on tryptic soy agar supplemented with 0.1% pyruvate (TSAP, a nonselective control medium); Leuschner, Baird, Donald, and Cox ( Enterobacter sakazakii is recognized as an emerging pathogen that has been documented to cause septicemia and meningitis in preterm and full-term infants (16,23,32,38,45). The bacterium also has been associated with necrotizing enterocolitis in neonates (43), as well as infections in elderly immunocompromised individuals (14, 23). Powdered infant formula (2,3,7,15,16,31,34,36,38,39,43,45) and powdered milk (13,15,21,31,36) have been epidemiologically implicated as sources of the pathogen.The method used by the U.S. Food and Drug Administration (FDA) (42) to detect E. sakazakii in powdered infant formula requires rehydration in sterile distilled water overnight at 36°C, followed by enrichment in Enterobacteriaceae enrichment (EE) broth overnight at 36°C, surface plating and streaking on violet red bile glucose (VRBG) agar, incubation overnight at 36°C, subculturing presumptive-positive colonies on tryptic soy agar (TSA), and incubating plates for 48 to 72 h at 25°C. Yellow-pigmented presumptive-positive E. sakazakii colonies are then subjected to confirmation tests using the API 20E biochemical-identification system, which requires an additional 18 to 24 h. EE broth and VRBG agar contain selective and differential ingredients (oxgall and brilliant green in EE broth and bile salts no. 3 and crystal violet in VRBG agar) that may prevent resuscitation of injured E. sakazakii cells, precluding their detection in powdered infant formula and other foods.Several media have been recently developed for detecting E. sakazakii in powdered infant formula. Oh and Kang (35) described a fluorogenic, differential, selective medium, Oh and Kang (OK) agar. A fluorogen, 4-methyl-umbelliferyl ␣-D-glucoside, serves as an indicator of the production of ␣-glucosidase by E. sakazakii. Bile salts no. 3 selects for enteric bacteria, and ferric citrate and sodium thiosulfate differentiate H 2 Sproducing Enterobacteriaceae. This fluorogen is also present in a differential, nonselective medium, Leuschner, Baird, Donald, and Cox (LBDC) agar, developed by Leuschner et al. (26) for the presumptive detection of E. sakazakii in infant formula.Iversen et al. (18) developed a differential, selective medium (Druggan-Forsythe-Iversen [DFI] medium) for recovering E. sakazakii in powdered infant formula. A chromogen, 5-bromo-4-chloro-3-indolyl-␣,D-glucopyranoside, acts as a diff...

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“…Cronobacter strains were isolated from a wide range of foods including milk, cheese, dried foods, meats, water, vegetables, rice, tea, herbs and spices Edelson-Mammel et al 2005;Friedemann 2007), various food production environments and households (Kandhai et al 2004;Gurtler et al 2005). The spectrum of Cronobacter-contaminated foods covers both raw and processed foods and the kind of processing is not restricted to dry products (Friedemann 2007).…”

Section: Introductionmentioning

confidence: 99%

Biochemical and molecular characterization of Cronobacter spp. (formerly Enterobacter sakazakii) isolated from foods

Turcovský

Kuniková

Drahovská

et al. 2010

Antonie van Leeuwenhoek

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The aim of this study was to identify and characterize Cronobacter spp. isolated from a range of foods. A total of 71 Cronobacter strains were isolated from 602 foods in our laboratory. The highest contamination was observed in foods of plant origin, e.g. spices, teas, chocolate, nuts, pastries and vegetables. On the basis of genus and species identification performed using genus-specific PCR, 16S rRNA sequencing and AFLP genotyping, most of the strains belonged to Cronobacter sakazakii. Biochemical profiling by the tests included in API 20E, complemented with relevant additional tests, classified the strains into 13 biogroups. AFLP genotyping facilitated discrimination of six main groups at the 70% similarity level and strain grouping correlated clearly with species identification. Our results indicate that molecular typing by AFLP may be applied as a useful tool not only for direct comparison of Cronobacter isolates, providing traceability, but also for the reliable species classification. Moreover, tracing of these bacteria in a wider variety of foods should be important to enhance the knowledge of their transmission.

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Survival of Enterobacter sakazakii in a Dehydrated Powdered Infant Formula

Cited by 107 publications

References 15 publications

Screening for<b><i> Cronobacter</i></b> Species in Powdered and Reconstituted Infant Formulas and from Equipment Used in Formula Preparation in Maternity Hospitals

Screening for<b><i> Cronobacter</i></b> Species in Powdered and Reconstituted Infant Formulas and from Equipment Used in Formula Preparation in Maternity Hospitals

Performance of Media for Recovering Stressed Cells of Enterobacter sakazakii as Determined Using Spiral Plating and Ecometric Techniques

Biochemical and molecular characterization of Cronobacter spp. (formerly Enterobacter sakazakii) isolated from foods

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