• 한국축산식품학회지
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• 제29권1호
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• pp.1-14
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• 2009

This study was to review the classification, detection and control of bacteriophage in fermented dairy products. Bacteriophage has lytic and/or lysogenic life cycles. Epidemiologically speaking, detected major phages are c2, 936 and p335. Among them p335 has been the largest concern in dairy industry. Traditionally, various analytical technologies, such as spot, starter activity, indicator test, ATP measurement and conductimetric analysis, have been used for the phage detection. In recent years, advanced methods such as flow cytometric method, petrifilm, enzyme linked immunosorbent assay (ELISA) and multiflex PCR diagnostic kit have been deveoloped. The phage contamination has been controlled by using heat, high-pressure treatment, and the combinations of heat and pressure, and/or chemical. Also some starter cultures with phage-resistant character have been developed to minimize the concentration of phages in dairy product. Bacteriophage inhibition media such as calcium medium was also mentioned. To prevent the contamination of bacteriophage in dairy industry, further researches on the detection and control of phage, and phage resistant starters are necessary in the future.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.135.1-135
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• 2003

A technique for detection of Xanthomonas axonopodis pv. citri, a causal bacterium of canker on Unshiu orange fruits, was developed using bacteriophage. Procedure for the detection was designed on the basis of the previous reports that one group(CPI) of X. axonopodis pv. citri bacteriophage and corresponding two Iysotypes distributed in Korea. First, fruit surface was washed with sterile distilled water and pellet was obtained from centrifugation. The pellet was resuspended in Wakimoto's potato semi-synthetic broth medium and divided equally into two parts. One part was heated in boiling water to kill bacterial cells. Bacteriophages(CP$_1$) were respectively added into two parts and 0.1 ml from each part was mixed with soft agar medium. After incubation for 18 hrs at 25$^{\circ}C$, the causal bacterium of canker was determined based on plaques formed on the medium. This procedure can be effectively used for detection of living bacterial pathogen on fruit surfaces of Unshiu orange.

• Journal of Microbiology and Biotechnology
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• 제33권7호
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• pp.964-972
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• 2023

Bacteriophage endolysins are peptidoglycan hydrolases composed of cell binding domain (CBD) and an enzymatically active domain. A phage endolysin CBD can be used for detecting bacteria owing to its high specificity and sensitivity toward the bacterial cell wall. We aimed to develop a method for detection of Enterococcus faecalis using an endolysin CBD. The gene encoding the CBD of ECP3 phage endolysin was cloned into the Escherichia coli expression vector pET21a. A recombinant protein with a C-terminal 6-His-tag (CBD) was expressed and purified using a His-trap column. CBD was adsorbed onto epoxy magnetic beads (eMBs). The bacterial species specificity and sensitivity of bacterial binding to CBD-eMB complexes were determined using the bacterial colony counting from the magnetic separations after the binding reaction between bacteria and CBD-eMB complexes. E. faecalis could bind to CBD-eMB complexes, but other bacteria (such as Enterococcus faecium, Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii, Streptococcus mutans, and Porphyromonas gingivalis) could not. E. faecalis cells were fixed onto CBD-eMB complexes within 1 h, and >78% of viable E. faecalis cells were recovered. The E. faecalis recovery ratio was not affected by the other bacterial species. The detection limit of the CBD-eMB complex for E. faecalis was >17 CFU/ml. We developed a simple method for the specific detection of E. faecalis using bacteriophage endolysin CBD and MBs. This is the first study to determine that the C-terminal region of ECP3 phage endolysin is a highly specific binding site for E. faecalis among other bacterial species.

• 식품저장과 가공산업
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• 제14권2호
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• pp.56-62
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• 2015

• Journal of Microbiology and Biotechnology
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• 제27권12호
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• pp.2151-2155
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• 2017

Bacteriophages have gained substantial attention as biocontrol and biorecognition agents, substituting antibodies. In this study, a Salmonella Enteritidis-specific bacteriophage, KFS-SE1, was isolated, identified, and characterized. This Siphoviridae phage infects S. Enteritidis with high specificity. This phage is highly stable under various pH (5-11), temperature ($4-60^{\circ}C$), and organic solvent conditions. The KFS-SE1 genome consisted of 59,715 bp with 73 predicted open reading frames and 57.14% GC content; it had a complete set of genes required for phage reconstruction. Comparative phylogenetic analysis of KFS-SE1 revealed that it was very similar to the other Salmonella phages in the Siphoviridae family. These characteristics suggest that KFS-SE1 with its high specificity and host lysis activity toward S. Enteritidis may have various potential applications.

• 한국식품과학회지
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• 제52권1호
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• pp.103-108
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• 2020

본 연구는 식품에서 문제가 되는 시가독소생성 대장균(STEC)을 박테리오파지 증폭 기법을 통해 검출하고자 시가독소 생성 대장균에 대한 박테리오파지를 분리하였고 분리된 4종의 파지와 기 분리된 2종의 박테리오파지를 혼합하여 사용하였다. 분리된 박테리오파지는 형태학적 특성 및 제한효소 절단 패턴 등을 통해서 동정하였다. 5종의 파지는 E. coli O157:H7 및 non-O157 시가독소 생성 대장균을 모두 저해하는 특징을 가지는 것으로 나타났다. 박테리오파지 증폭 기법에서 중요한 단계인 세균에 감염되지 않은 박테리오파지를 제거하기 위해 10% (v/v) ferrous ammonium sulfate (FAS)을 사용하였으며 약 7-9 log PFU/mL 수준의 박테리오파지를 10분 내로 제거하는 것을 확인하였다. 시가독소 생성 대장균인 E. coli NCCP 13937을 검출하기 위해서는 약 6 log PFU/mL 이상의 박테리오파지 혼합액의 농도 및 약 4-5 log CFU/mL 이상의 목표 균주가 필요한 것으로 나타났다. 이러한 조건을 바탕으로 실제 판매되고 있는 신선식품에서 시가독소생성 대장균을 검출한 결과, 5시간 이내에 증폭된 약 2-3 log PFU/mL의 plaque를 통해 검출이 가능한 것을 확인하였다. 따라서 본 연구를 통해 박테리오파지 혼합액을 이용한 증폭 기법을 통해 시가독소 생성 대장균의 오염 여부를 보다 효율적으로 확인할 수 있음을 보여주었고 이를 적용한 제품을 개발하여 검출 단계의 간편화가 가능할 것으로 판단된다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2008년도 International Meeting of the Microbiological Society of Korea
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• pp.135-135
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• 2008

Various biosensors were evaluated for identifying and detecting foodborne pathogens in a rapid and effective manner. First, five strains of Escherichia coli and six strains of Salmonella were identified using Fourier transform infrared spectroscopy and a statistical program. For doing this, lipopolysaccharides (LPSs) and outer membrane proteins (OMPs) were extracted from a cell wall of each bacterial strain. As a result, each strain was identifed at the level of 97% for E. coli and 100% for Salmonella. Second, E. coli O157:H7, S. Enteritidis, and Listeria monocytogenes were identified by multiplex PCR products from four specific genes of each bacteria using a capillary electrophoresis (CE). Also, ground beef for E. coli O157:H7, lettuce for S. Enteritidis, and hot dog for L. monocytogenes were used to determine the possibility of detecting pathogens in foods. Foods inoculated with respective pathogen were cultivated for six hours and multiplex PCR products were obtained and assessed. The minimum detection levels of tested bacteria were <10 cells/g, <10 cells/g, and $10^4$ cells/g for E. coli O157:H7, S. Enteritidis, and L. monocytogenes, respectively. Third, it was possible to detect S. Typhimurium in a pure culture and lettuce by a bioluminescence-based detection assay using both recombinant bacteriophage P22::luxI and a bioluminescent bioreporter. In addition, bacteriophage T4 was quantitatively monitored using E. coli including luxCDABE genes.

• Journal of Microbiology and Biotechnology
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• 제23권3호
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• pp.357-363
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• 2013

The identification of bacteriophage proteins on the surface of Lactobacillus rhamnosus Pen was performed by LC-MS/MS analysis. Among the identified proteins, we found a phage-derived major tail protein, two major head proteins, a portal protein, and a host specificity protein. Electron microscopy of a cell surface extract revealed the presence of phage particles in the analyzed samples. The partial sequence of genes encoding the major tail protein for all tested L. rhamnosus strains was determined with specific primers designed in this study. Next, RT-PCR analysis allowed detection of the expression of the major tail protein gene in L. rhamnosus strain Pen at all stages of bacterial growth. The transcription of genes encoding the major tail protein was also proved for other L. rhamnosus strains used in this study. The present work demonstrates the spontanous release of prophage-encoded particles by a commercial probiotic L. rhamnosus strain, which did not significantly affect the bacterial growth of the analyzed strain.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2000년도 국제심포지엄 및 제26차 추계학술발표회
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• pp.121-121
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• 2000

• 환경생물
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• 제20권3호
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• pp.189-196
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• 2002

The direct detection of intestinal pathogens and viruses often requires costly, tedious, and time-consuming procedures. These requirements developed a test to show that the water was contaminated with sewage-borne pathogens by assessing the hygienic quality of water based on indicator microorganisms whose presence indicates that pathogenic microorganisms may also be present. Various groups of microorganisms have been suggested and used as indicator microorganisms. Proposed and commonly used microbial indicators are total coliforms, fecal coliforms, fecal streptococci, Clostridium perfringens, heterotrophic plate count, bacteriophage, and so on. Unfortunately, most, if not all, of these indicators are not ideal because of the sensitivity and resistance to environment stresses and disinfection. However, the development of gene probes and PCR technology may give hope for the discovery of rapid and simple methods toy detecting small number of fecal pathogens in various environments.