• 한국동물위생학회지
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• 제36권2호
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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.

• 한국축산식품학회지
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• 제38권2호
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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.

• 미생물학회지
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• 제48권4호
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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.

• 한국식품영양학회지
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• 제28권4호
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• pp.728-736
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• 2015

Cronobacter spp.는 Salmonella spp.와 함께 조제분유에서 발견되는 미생물 중 위험도가 가장 높은 category A에 속하는 균으로 알려져 있다. 1958년 영국에서 처음으로 유아의 뇌수 막염의 원인균으로 보고되었으며, 감염 후 신생아에게서 괴사성 장염, 패혈증 등을 일으켜 후유증으로 시력과 청력 상실 및 신경마비를 일으키기도 한다. 이러한 위험성 때문에 Cronobacter spp.의 신속 검출 및 진단은 식중독 예방에 있어서 중요하다. 따라서 2002년 미국 식품의약품안전국에서는 분유에서의 Cronobacter spp.를 EE broth, VRBG 배지를 이용해 균을 분리 하고, TSA 배지에 순수분리 후 노란색을 발하는 colony를 생화학적 실험을 통해 검출하는 방법을 제시했다. 또한, 우리나라 식품공전에서도 배지를 이용하여 Cronobacter spp.를 검출 하는 방법에 대해 등재하였다. 하지만 배지배양법을 기반으로 하는 Cronobacter spp.의 검출방법은 검출에 소요되는 시간과 노동력 등이 비효율적이라는 단점이 있다. 따라서 많은 시간이 소요되는 배지배양법을 보완하고자 PCR, real-time PCR 방법 및 최근에는 PCR기법과 ELISA, CE-LIF 등을 결합하여 검출하는 방법이 개발되어 Cronobacter spp.의 검출에 사용되기도 하였다. Cronobacter spp.의 검출에 사용되고 있는 분자생물학적 기반의 PCR 및 real-time PCR 기법은 민감도와 특이도가 좋으며, 배지배양법에 의한 검출방법에 비해 검출 시간을 획기적으로 줄일 수 있다는 장점이 있다. 하지만 까다로운 실험과정과 조작에 있어서 필요한 전문적인 기술이 필요함은 한계점으로 사료된다. 면역학적 방법에 의한 Cronobacter spp. 검출에 관한 연구를 통해, 분석에 소요되는 상당시간을 단축할 수 있었으며, 민감하고 특이적인 검출이 가능함을 보여주었다. 특히 일부 연구보고에서 면역학적 검출방법은 고가의 장비가 필요 없으며, 간단한 지침에 따라 모니터링 업무의 수행이 가능하다고 하였다. 면역학적 검출방법에는 ELISA 방법 외에도 immunomagnetic bead, liposome, immunochromatographic strip 등이 개발되고 있다. 우리나라 식품의약품안전처에서는 영 유아 대상 식품의 안전관리를 강화하고자 Cronobacter spp.에 대해서는 '불검출'로 기준을 설정 운영하고 있으며, 지속적으로 이에 관한 규정을 강화하고 있는 실정이다. 따라서, 식품산업체 및 식품 의 제조, 가공, 유통 현장에서 쉽게 모니터링이 가능하며, 신속, 민감하고 특이적인 검출방법의 개발은 지속되어야 한다.

• Journal of Dairy Science and Biotechnology
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• 제36권3호
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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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• 제26권11호
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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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• 제4권2호
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• pp.56-64
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• 2015

• Journal of Species Research
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• 제9권2호
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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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• 제23권1호
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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%.

• 한국식품과학회지
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• 제48권5호
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• pp.437-444
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• 2016

최근 건강과 위생에 대한 소비자의 의식 향상으로 인해 농수축산 분야를 비롯한 식품의 가공 유통 분야에서도 식품의 안전성 확보를 위한 시험 검사가 실시되고 있고, HACCP과 같은 식품안전관리 프로그램의 조기 도입을 유도하고 있어 식품중독균에 대한 검사량이 증가하고 있다. 이에 따른 신속, 정확하고 대량의 시료를 처리할 수 있는 식품중독균 검사의 필요성이 증가되고 있다. 국내 식품 미생물의 확인시험방법은 전통적인 미생물 동정법인 그램 염색 등과 같은 형태학적 특성과 생화학적 분석에 의해서 주로 확인되는데, 확인 과정이 복잡하고 장시간이 소요된다. 이를 극복하기 위한 새로운 미생물 동정법인 MALDI-TOF 질량분석기반 미생물 동정법을 식품의 식품중독균 검사에 적용하기 위해 식품공전에서 주로 검사하는 식품중독균 10종에 대한 질량 패턴 데이터를 국내 질량분석 데이터베이스인 MicroID에 적용하였다. 표준 균주와 식품중독균이 검출된 시료에서 분리한 균으로 비교했을 때 질량분석기반 미생물 동정은 현재 사용되고 있는 생화학적 분석결과와 일치한 결과를 보여주었다. 또한, 식품중독균을 포함한 국내 미생물 균주를 이용해서 구축한 데이터베이스, MicroID는 기존의 상용화된 해외 MALDI-TOF 질량분석 데이터베이스 Biotyper와 동등 이상의 정확도를 나타내었다. 국내 식품관련 미생물에 대한 질량스펙트럼을 추가하여 데이터베이스를 지속적으로 확장시키면 신속 정확한 미생물 동정법으로 자리매김할 수 있을 것이다.