• Korean Journal of Veterinary Service
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• v.36 no.2
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• pp.67-71
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• 2013

Neonatal infection caused by Cronobacter species can result in serious illnesses such as bacteremia, septicemia, meningitis, and death in at-risk infants who are orally fed contaminated reconstituted powdered infant formulas. The objective of this study was to compare the virulence among three Cronobacter species strains by using an animal model for human neonatal Cronobacter species infections. We acquired timed-pregnant ICR mice and all owed them to give birth naturally. On postnatal day 3, each pup was administered orally a total dose of $1{\times}10^7$ CFU Cronobacter species strain 3439, CDC 1123-79, and 3231. Mice were observed twice daily for morbidity and mortality. At postnatal day 10, the remaining pups were euthanized, and brain, liver, and cecum were excised and analyzed for the presence of Cronobacter species. Cronobacter species were isolated from cecum and other tissues in inoculated mice. In the tissues of Cronobacter species infected mice, meningitis and gliosis were detected in the brain. In this study, we identified the virulence among Cronobacter species strains by using a neonatal mice model which was a very effective animal model for human neonatal Cronobacter species infections.

• Food Science of Animal Resources
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• v.38 no.2
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• pp.376-390
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• 2018

Cronobacter species have been associated with disease outbreaks and sporadic infections, particularly in premature and immunocompromised infants. Cronobacter species can cause foodborne infections such as neonatal meningitis, septicaemia and necrotising enterocolitis. Accordingly, there is an urgent need to control and monitor the Cronobacter species in food, especially in powdered infant formula (PIF) and other baby foods. Therefore, in this review, the isolation and prevalence of Cronobacter species in infant food including PIF and the recent advance of detection methods are discussed for the better understanding on the current research status of Cronobacter species.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.229-239
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• 2012

Cronobacter spp. (formerly Enterobacter sakazakii), a Gram-negative bacillus, is a rare cause of meningitis and central nervous system infections. In England, the first case infected by this organism occurred in 1958. By July 2008, approximately 120 documented cases of Cronobacter spp. infection and at least 27 deaths have been identified from all around the world in the published literature and in reports submitted by public health sectors. In 2007, it was proposed by European organizations that the original taxonomy of E. sakazakii would be revised, to consist of five new species moved to a new genus, and identified as "Cronobacter". E. sakazakii has thus now been reclassified as 6 separate species in the new genus, Cronobacter, gen. nov., within the Enterobacteriaceae family. The new species are presently Cronobacter sakazakii, C. turicensis, C. malonaticus, C. muytjensii, and C. dublinensis; the sixth species is identified simply as genomospecies I, as currently including only two representative strains. The objectives of this review are to provide insight on (1) the classification and taxonomy of Cronobacter spp., (2) its clinical etiology and pathogenicity, (3) prequency of Cronobacter spp. in different categories of ready-to-eat food other than infant formula, (4) methods for detecting, isolating and typing Cronobacter spp., and (5) recent research trends for detecting Cronobacter spp.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.728-736
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• 2015

Cronobacter species (Cronobacter spp.), previously known as Enterobacter sakazakii, are gram negative food borne pathogenic bacteria. They pose a very high risk of infection to neonates and immuno-compromised individuals and can affect the human central nervous system. Consequently, survivors often suffer from severe neurological impairment including hydrocephalus, quadriplegia, and developmental delays. Cronobacter spp. were not only isolated from plant food and products such as cereals, fruits, vegetables, legume products, herbs, and spices but also from animal source foods such as milk, meat, fish, and products made from these foods. Therefore, rapid detection of Cronobacter spp. is essential for food safety. Many detection methods have been developed since the Cronobacter spp. were first reported. However, the development of more rapid, sensitive, and easy-to-use detection methods for the Cronobacter spp. is required. In this review, our aim was to study and compare the available detection methods for Cronobacter spp., including culture-based, molecular biology-based, and immunology-based methods. This study will contribute to the development of new and rapid detection method for Cronobacter spp.

• Journal of Dairy Science and Biotechnology
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• v.36 no.3
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• pp.146-154
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• 2018

There are more than 25 species of Mentha plants, which are aromatic perennial herbs. Currently, these species are being widely used with great interest because of various clinical findings regarding their health benefits. This is due to the abundance of volatile compounds that could expedite environmental interactions such as protection against herbivores, parasites, pathogens, and so on. Therefore, in this study, the antimicrobial effect of Mentha piperita (peppermint) oil on Bacillus cereus, Staphylococcus aureus, Cronobacter sakazakii, and Salmonella Enteritidis were investigated using the spot-on-lawn method. The results show that Mentha piperita (peppermint) oil exhibited antimicrobial activities against Bacillus cereus, Staphylococcus aureus, and Cronobacter sakazakii; however, it did not inhibit the growth of Salmonella Enteritidis. This shows that the antimicrobial effect of Mentha piperita (peppermint) oil is effective against both Gram-positive and Gram-negative bacteria. Hence, in the present study, Mentha piperita (peppermint) oil was shown to have strong antimicrobial activities; it could be used as a potential food additive for improving the quality of various milk-based products due to its various bioactive properties. Future studies should be conducted for manufacturing functional dairy products with the addition of peppermint oil to prevent and/or alleviate specific diseases.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1855-1862
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• 2016

Cronobacter sakazakii (C. sakazakii) is a foodborne pathogen, posing a high risk of disease to infants and immunocompromised individuals. In order to develop a quick, easy, and sensitive assay for detecting C. sakazakii, a rabbit anti-C. sakazakii immunoglobulin G (IgG) was developed using sonicated cell protein from C. sakazakii. The developed anti-C. sakazakii (IgG) was of good quality and purity, as well as species-specific. The developed rabbit anti-C. sakazakii IgG was attached to the surface of a sulforhodamine B-encapsulated liposome to form an immunoliposome. A test strip was then prepared by coating goat anti-rabbit IgG onto the control line and rabbit anti-C. sakazakii IgG onto the test line, respectively, of a plastic-backed nitrocellulose membrane. A purple color signal both on the test line and the control line indicated the presence of C. sakazakii in the sample, whereas purple color only on the control line indicated the absence of C. sakazakii in the sample. This immunochromatographic strip assay could produce results in 15 min with a limit of detection of $10^7CFU/ml$ in C. sakazakii culture. The immunochromatographic strip assay also showed very good specificity without cross-reactivity with other tested Cronobacter species. Based on these results, the developed immunochromatographic strip assay is efficient for the detection of C. sakazakii and has high potential for on-site detection.

• 축산식품과학과 산업
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• v.4 no.2
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• pp.56-64
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• 2015

• Journal of Species Research
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• v.9 no.2
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• pp.105-116
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• 2020

A total of 37 anaerobic bacteria strains within the classes Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Bacteroidia, Flavobacteriia, Bacilli, Clostridia, and Fusobacteriia were isolated from freshwater and sediment of the Geum River in Korea. The unreported species were related with Rhizobium and Oleomonas of the class Alphaproteobacteria; Acidovorax, Pseudogulbenkiania, and Aromatoleum of the class Betaproteobacteria; Tolumonas, Aeromonas, Cronobacter, Lonsdalea, and Phytobacter of the class Gammaproteobacteria; Bacteroides, Dysgonomonas, Macellibacteroides, and Parabacteroides of the class Bacteroidia; Flavobacterium of the class Flavobacteriia; Bacillus and Paenibacillus of the class Bacilli; Clostridium, Clostridioides, Paraclostridium, Romboutsia, Sporacetigenium, and Terrisporobacter of the class Clostridia; and Cetobacterium and Ilyobacter of the class Fusobacteriia. A total of 37 strains, with >98.7% 16S rRNA gene sequence similarity with validly published bacterial species, but not reported in Korea, were determined to be unrecorded anaerobic bacterial species in Korea.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.40-46
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• 2013

A variety of nuruk were collected from various provinces in Korea, and their microflora profiles were analyzed at the species level. A total of 42 nuruk samples were collected and when the viable cell numbers in these nuruk were enumerated, the average cell numbers of bacteria, fungi, yeast, and lactic acid bacteria from all nuruk were 7.21, 7.91, 3.49, and 4.88 log CFU/10 g, respectively. There were no significant differences in viable cell numbers of bacteria or fungi according to regions collected. Bacillus amyloliquefaciens and B. subtilis were the predominant bacterial strains in most samples. A significant portion, 13 out of 42 nuruk, contained foodborne pathogens such as B. cereus or Cronobacter sakazakii. There were various species of lactic acid bacteria such as Enterococcus faecium and Pediococcus pentosaceus in nuruk. It was unexpectedly found that only 13 among the 42 nuruk samples contained Aspergillus oryzae, the representative saccharifying fungi in makgeolli, whereas a fungi Lichtheimia corymbifera was widely distributed in nuruk. It was also found that Pichia jadinii was the predominant yeast strain in most nuruk, but the representative alcohol fermentation strain, Saccharomyces cerevisiae, was isolated from only 18 out of the 42 nuruk. These results suggested that a variety of species of fungi and yeast were distributed in nuruk and involved in the fermentation of makgeolli. In this study, a total of 64 bacterial species, 39 fugal species, and 15 yeast species were identified from nuruk. Among these strains, 37 bacterial species, 20 fungal species, and 8 yeast species were distributed less than 0.1%.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.437-444
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• 2016

Rapid and reliable identification of microorganisms is important to maintain food quality and to control safety. MALDI-TOF MS-based identification methods are relatively fast and simple compared to other conventional methods including gram staining and biochemical characterization. A colony on subcultured media can be directly prepared on the analysis plate without further complex treatments. In this study, we confirmed the applicability of MALDI-TOF MS-based identification of foodborne pathogens such as Salmonella Enteritidis/Typhimurium, Staphylococcus aureus, Vibrio parahaemolyticus, Clostridium perfringens, Listeria monocytogenes, Yersinia enterocolitica, Bacillus cereus, Campylobacter jejuni, Campylobacter coli, and Cronobacter sakazakii on the Korea Food Standard Codex. MALDI-TOF MS data of the pathogenic reference strains were incorporated into a commercial MicroID (ASTA Inc.) database. Other pathogenic reference strains and seven isolates from various food samples were correctly identified to the species level by using the MicroID database. In conclusion, MALDI-TOF MS is comparable with commercial biochemical identification.