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

2005 ◽  
Vol 71 (12) ◽  
pp. 7661-7669 ◽  
Author(s):  
J. B. Gurtler ◽  
L. R. Beuchat
Keyword(s):  
Infant Formula ◽  
Fecal Coliform ◽  
Colony Development ◽  
Powdered Infant Formula ◽  
Enterobacter Sakazakii ◽  
Order Of Growth ◽  
Growth Indices ◽  
Selective Media ◽  
General Order ◽  
Stressed Cells

ABSTRACT 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 (LBDC) agar (a differential, nonselective medium); Oh and Kang agar (OK); fecal coliform agar (FCA); Druggan-Forsythe-Iversen (DFI) medium; violet red bile glucose (VRBG) agar; and Enterobacteriaceae enrichment (EE) agar. With the exception of desiccation-stressed cells, suspensions of stressed cells were also plated on these media and on R&F Enterobacter sakazakii chromogenic plating (RF) medium using the ecometric technique. The order of performance of media for recovering control and heat-, freeze-, acid-, and alkaline-stressed cells by spiral plating was TSAP > LBDC > FCA > OK, VRBG > DFI > EE; the general order for recovering desiccated cells was TSAP, LBDC, FCA, OK > DFI, VRBG, EE. Using the ecometric technique, the general order of growth indices of stressed cells was TSAP, LBDC > FCA > RF, VRBG, OK > DFI, EE. The results indicate that differential, selective media vary greatly in their abilities to support resuscitation and colony formation by stressed cells of E. sakazakii. The orders of performance of media for recovering stressed cells were similar using spiral plating and ecometric techniques, but results from spiral plating should be considered more conclusive.

Enterobacteriaceae in Dehydrated Powdered Infant Formula Manufactured in Indonesia and Malaysia

2006 ◽  
Vol 69 (12) ◽  
pp. 3013-3017 ◽  
Author(s):  
SRI ESTUNINGSIH ◽  
CLAUDIA KRESS ◽  
ABDULWAHED A. HASSAN ◽  
ÖMER AKINEDEN ◽  
ELISABETH SCHNEIDER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Health Risk ◽  
Southeast Asia ◽  
Infant Formula ◽  
Enterobacter Cloacae ◽  
Powdered Infant Formula ◽  
Enterobacter Sakazakii ◽  
Opportunistic Pathogens ◽  
Selective Media

To determine the occurrence of Salmonella and Shigella in infant formula from Southeast Asia, 74 packages of dehydrated powdered infant follow-on formula (recommended age, >4 months) from five different manufacturers, four from Indonesia and one from Malaysia, were analyzed. None of the 25-g test portions yielded Salmonella or Shigella. However, further identification of colonies growing on selective media used for Salmonella and Shigella detection revealed the frequent occurrence of several other Enterobacteriaceae species. A total of 35 samples (47%) were positive for Enterobacteriaceae. Ten samples (13.5%) from two Indonesian manufacturers yielded Enterobacter sakazakii. Other Enterobacteriaceae isolated included Pantoea spp. (n = 12), Escherichia hermanii (n = 10), Enterobacter cloacae (n = 8), Klebsiella pneumoniae subsp. pneumoniae (n = 3), Citrobacter spp. (n = 2), Serratia spp. (n = 2), and Escherichia coli (n = 2). To our knowledge, this is the first report to describe the contamination of dehydrated powdered infant formula from Indonesia with E. sakazakii and several other Enterobacteriaceae that could be opportunistic pathogens. Improper preparation and conservation of these products could result in a health risk for infants in Indonesia.

Enterobacter sakazakii in Dried Infant Formulas and Milk Kitchens of Maternity Wards in São Paulo, Brazil

2009 ◽  
Vol 72 (1) ◽  
pp. 37-42 ◽  
Author(s):  
GABRIELA PALCICH ◽  
CINTIA de MORAES GILLIO ◽  
LINA CASALE ARAGON-ALEGRO ◽  
FRANCO J. PAGOTTO ◽  
JEFFREY M. FARBER ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Neonatal Intensive Care Unit ◽  
Infant Formula ◽  
Neonatal Intensive Care ◽  
Room Temperature ◽  
Sao Paulo ◽  
Powdered Infant Formula ◽  
São Paulo ◽  
Enterobacter Sakazakii

This study was the first conducted in Brazil to evaluate the presence of Enterobacter sakazakii in milk-based powdered infant formula manufactured for infants 0 to 6 months of age and to examine the conditions of formula preparation and service in three hospitals in São Paulo State, Brazil. Samples of dried and rehydrated infant formula, environments of milk kitchens, water, bottles and nipples, utensils, and hands of personnel were analyzed, and E. sakazakii and Enterobacteriaceae populations were determined. All samples of powdered infant formula purchased at retail contained E. sakazakii at <0.03 most probable number (MPN)/100 g. In hospital samples, E. sakazakii was found in one unopened formula can (0.3 MPN/100 g) and in the residue from one nursing bottle from hospital A. All other cans of formula from the same lot bought at a retail store contained E. sakazakii at <0.03 MPN/100 g. The pathogen also was found in one cleaning sponge from hospital B. Enterobacteriaceae populations ranged from 101 to 105 CFU/g in cleaning aids and <5 CFU/g in all formula types (dry or rehydrated), except for the sample that contained E. sakazakii, which also was contaminated with Enterobacteriaceae at 5 CFU/g. E. sakazakii isolates were not genetically related. In an experiment in which rehydrated formula was used as the growth medium, the temperature was that of the neonatal intensive care unit (25°C), and the incubation time was the average time that formula is left at room temperature while feeding the babies (up to 4 h), a 2-log increase in levels of E. sakazakii was found in the formula. Visual inspection of the facilities revealed that the hygienic conditions in the milk kitchens needed improvement. The length of time that formula is left at room temperature in the different hospitals while the babies in the neonatal intensive care unit are being fed (up to 4 h) may allow for the multiplication of E. sakazakii and thus may lead to an increased health risk for infants.

scholarly journals Evaluation of a Revised U.S. Food and Drug Administration Method for the Detection and Isolation of Enterobacter sakazakii in Powdered Infant Formula: Precollaborative Study

2009 ◽  
Vol 92 (3) ◽  
pp. 862-872 ◽  
Author(s):  
Yi Chen ◽  
Thomas S Hammack ◽  
Kwang-Young Song ◽  
Keith A Lampel
Keyword(s):  
Infant Formula ◽  
Drug Administration ◽  
Validation Study ◽  
Real Time Pcr ◽  
Food And Drug Administration ◽  
Powdered Infant Formula ◽  
Enterobacter Sakazakii ◽  
Administration Method ◽  
Pcr Technology ◽  
Atypical Strains

Abstract A revised U.S. Food and Drug Administration (FDA) method for the detection and isolation of Enterobacter sakazakii in powdered infant formula was developed based on real-time PCR technology complemented by culture isolation on chromogenic agars. A validation study was conducted to compare the revised FDAmethod to the reference FDAmethod. Casein and soy powdered infant formula inoculated with morphologically typical and atypical strains of E. sakazakii were analyzed. Valid results were obtained from 360 test portions and controls and showed that the revised FDAmethod is significantly better (P < 0.05) than the reference FDAmethod for the detection of typical E. sakazakii strains and the two methods are equivalent for the detection of atypical E. sakazakii strains.

Gamma Radiation Sensitivity of Enterobacter sakazakii in Dehydrated Powdered Infant Formula

2006 ◽  
Vol 69 (6) ◽  
pp. 1434-1437 ◽  
Author(s):  
J. W. LEE ◽  
S. H. OH ◽  
J. H. KIM ◽  
H. S. YOOK ◽  
M. W. BYUN
Keyword(s):  
Radiation Dose ◽  
Gamma Radiation ◽  
Infant Formula ◽  
Marked Effect ◽  
Radiation Sensitivity ◽  
Sensory Properties ◽  
Hot Water ◽  
Powdered Infant Formula ◽  
Enterobacter Sakazakii ◽  
Nutritional Studies

The observed Enterobacter sakazakii D10-values for tryptic soy broth and dehydrated powdered infant formula were 0.27 ± 0.05 and 0.76 ± 0.08 kGy, respectively. A decrease of approximately 3 log in the dehydrated powdered infant formula was obtained by irradiation with 3.0 kGy or rehydration with hot water at 80°C. No recoverable bacteria were found in the powdered infant formula irradiated at 5.0 kGy and stored, either before or after rehydration. A radiation dose of up to 5.0 kGy had no marked effect on the sensory properties of the dehydrated powdered infant formula after rehydration and heating. Gamma radiation could potentially be used to inactivate E. sakazakii in dehydrated powdered infant formula; however, nutritional studies need to be conducted before the use of radiation can be recommended.

Dry Stress and Survival Time of Enterobacter sakazakii and Other Enterobacteriaceae in Dehydrated Powdered Infant Formula

2007 ◽  
Vol 70 (9) ◽  
pp. 2111-2117 ◽  
Author(s):  
JUNCAL CAUBILLA BARRON ◽  
STEPHEN J. FORSYTHE
Keyword(s):  
Infant Formula ◽  
Salmonella Enteritidis ◽  
Klebsiella Oxytoca ◽  
Powdered Infant Formula ◽  
Enterobacter Sakazakii ◽  
Opportunistic Pathogens ◽  
Term Survival ◽  
E Coli ◽  
Sterile Product

Powdered infant formula is not a sterile product, and opportunistic pathogens could multiply in the reconstituted product, resulting in neonatal infections. In this study, the generation of sublethally injured Enterobacteriaceae during desiccation and their persistence in dehydrated powdered infant formula was assessed during a 2.5-year period. The study included 27 strains of Enterobacter sakazakii, Enterobacter cloacae, Salmonella Enteritidis, Citrobacter koseri, Citrobacter freundii, Escherichia coli, Escherichia vulneris, Pantoea spp., Klebsiella oxytoca, and Klebsiella pneumoniae. The number of sublethally injured cells generated during desiccation was lower for K. oxytoca, Pantoea spp., Salmonella Enteritidis, and capsulated strains of E. sakazakii than for the other Enterobacteriaceae. The Enterobacteriaceae could be divided into three groups with respect to their long-term survival in the desiccated state. C. freundii, C. koseri, and E. cloacae were no longer recoverable after 6 months, and Salmonella Enteritidis, K. pneumoniae, and E. coli could not be recovered after 15 months. Pantoea spp., K. oxytoca, and E. vulneris persisted over 2 years, and some capsulated strains of E. sakazakii were still recoverable after 2.5 years.

Development of an immobilization and detection method of Enterobacter sakazakii from powdered infant formula

2008 ◽  
Vol 25 (5) ◽  
pp. 648-652 ◽  
Author(s):  
Yanhong Zhou ◽  
Qingping Wu ◽  
Xiaoke Xu ◽  
Xiaojuan Yang ◽  
Yingwang Ye ◽  
...  
Keyword(s):  
Infant Formula ◽  
Detection Method ◽  
Powdered Infant Formula ◽  
Enterobacter Sakazakii

Evaluation of a New Enrichment Broth for Detection of Cronobacter spp. in Powdered Infant Formula

2011 ◽  
Vol 74 (3) ◽  
pp. 387-393 ◽  
Author(s):  
M. A. AL-HOLY ◽  
J.-H. SHIN ◽  
T. M. OSAILI ◽  
B. A. RASCO
Keyword(s):  
Infant Formula ◽  
Rapid Detection ◽  
Brain Heart Infusion ◽  
Sodium Deoxycholate ◽  
Powdered Infant Formula ◽  
Lauryl Sulfate ◽  
Enterobacter Sakazakii ◽  
Formula Milk ◽  
Enrichment Broth ◽  
Infant Formula Milk

The aim of this study was to investigate the potential of using Al-Holy–Rasco (AR) medium, a novel broth for detection and isolation of Cronobacter spp. in infant formula milk (IFM). The new medium's composition is generic brain heart infusion broth with the addition of 1% NaCl, 15% sucrose, and 0.80 g/liter sodium deoxycholate as selective ingredients. AR broth outperformed Enterobacteriaceae enrichment broth (EE), Enterobacter sakazakii enrichment broth (ESE), modified lauryl sulfate broth, and milk as enrichment media to stimulate the growth of a cocktail of 10 strains of Cronobacter. Additionally, AR broth significantly suppressed the growth of competing non-Cronobacter Enterobacteriaceae as compared with EE, ESE, modified lauryl sulfate broth, and milk. The recovery of desiccated Cronobacter (1 to 5,000 CFU/100 g) from powdered IFM in the presence of competing non-Cronobacter Enterobacteriaceae was determined by EE, ESE, and AR broth with 10 and 15% sucrose. AR broth with 15% sucrose outperformed all other examined broths and recovered Cronobacter from all samples tested at all Cronobacter concentrations. AR broth must be validated before it can be used for rapid detection and isolation of Cronobacter from powdered IFM.

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