Earticle

유·무선 혼재 및 이동성이 증가한 환경에서 단말은 링크 분리, 포트 이동, 무선 로밍, 악성 AP(Evil Twin) 등 경계 상황으 로 신뢰 구간을 이탈할 수 있다. 이때 단말이 자동 DHCP 재획득으로 비인가 네트워크에서도 통신을 지속하면 데이터 유출과 공격면 확대로 이어질 수 있다. 본 연구는 트레이 기반 엔드포인트 NAC 에이전트를 설계·구현하고, 연결 맥락이 불명확할 때 격리 우선(Isolation-First) 원칙으로 통신면을 즉시 축소한 뒤 동일망 복귀가 검증된 경우에만 복구를 허용하는 절차를 제안 한다. 단절 확정 시 방화벽 전면 차단과 APIPA 초기화를 결합해 격리하고 NIC는 관측을 위해 ‘사용함’을 유지한다. 복구는 사 용자 의사(키 입력)와 프로파일/DNS suffix, SSID/BSSID, 게이트웨이 IP/MAC, 서브넷, Neighbor 유사도(Jaccard) 등 다중 지문 규칙으로 검증한다. 동일망 검증 592회 중 531회(89.7%)가 통과했고 61회는 실패했다. 실패의 85.2%는 IP 미할당/프로파 일 식별 지연이 확인되었고 로그 기반 평가 시 격리 적용은 약 10초, 정상 복구 중앙값은 60.5초로 관측되었다.

In environments with mixed wired/wireless access and increasing mobility, endpoints can leave the trusted zone due to boundary conditions such as link switching, port moves, Wi-Fi roaming, or malicious access points (Evil Twin). If a device automatically renews DHCP and continues communicating on an unauthorized network, it can increase data-leak risk and expand the attack surface. This study designs and implements a tray-based endpoint NAC agent and proposes an isolation-first procedure: when connection context is unclear, it immediately reduces network exposure and restores access only after verifying a return to the same trusted network. Upon confirmed disconnection, it enforces full firewall blocking and resets to APIPA while keeping the NIC enabled for monitoring. Recovery requires user intent (key input) and multi-fingerprint validation using rules such as profile/DNS suffix, SSID/BSSID, gateway IP/MAC, subnet, and neighbor similarity (Jaccard). In 592 same-network verification attempts, 531 (89.7%) passed and 61 failed; 85.2% of failures were due to missing IP assignment or delayed profile identification. Log-based evaluation showed ～10 seconds to apply isolation and a median of 60.5 seconds for normal recovery.

Bacteriophages of Acidovorax citrulli, the causal agent of bacterial fruit blotch, were isolated from 39 watermelon, pumpkin, and cucumber leaf samples collected from various regions of Korea and tested against 18 A. citrulli strains. Among the six phages isolated, ACP17 forms the largest plaque, and exhibits the morphology of phages in the Myoviridae family with a head diameter of $100{\pm}5nm$ and tail length of $150{\pm}5nm$. ACP17 has eclipse and latent periods of $25{\pm}5min$ and $50{\pm}5min$, respectively, and a burst size of 120. The genome of ACP17 is 156,281 base pairs with a G + C content of 58.7%, 263 open reading frames, and 4 transfer RNA genes. Blast search and phylogenetic analysis of the major capsid protein showed that ACP17 has limited homology to two Stentrophomonas phages, suggesting that ACP17 is a new type of Myoviridae isolated from A. citrulli.

A 60-year-old man presented with a 1-day history of fever, vomiting, and diarrhea. He was diagnosed with severe septic shock on the basis of a body temperature of 38.9oC, heart rate of 92/min, respiratory rate of 25/min, WBC count of 22,970/μL, C-reactive protein (CRP) level of 136 mg/L, blood urea nitrogen (BUN) of 34.0 mg/dL, and creatinine of 2.98 mg/dL. On blood culture, Gram-positive cocci were detected in all 6 bottles. Small grayish non-hemolytic colonies were found on blood agar plates after incubation at 37oC for 2 days. The isolates were negative for catalase and L-pyrrolidonyl-β-naphthylamide hydrolysis, and positive for bile-esculin and leucine aminopeptidase activity. The strain was identified as Streptococcus gallolyticus subsp. pasteurianus using Vitek2 GP II systems. We performed 16S rRNA gene sequencing and detected 100% identity with S. gallolyticus subsp. pasteurianus strain CIP 107122T (1,345/1,345-bp). The patient recovered after receiving ampicillin-sulbactam. This is the first report of phenotypic and genetic identification of S. gallolyticus subsp. pasteurianus causing severe septic shock in a Korean patient.

An equine herpesvirus-4 (EHV-4) was isolated in nasal swabs collected in a horse showing respiratory clinical signs. Equine dermis cells inoculated with the sample were observed with characteristic viral cytopathic effects after 3 days of postinoculation and the infected cells exhibited bright intracelluar fluorescence by indirect immunofluorescence assay. At the nucleotide level, the partial glycoprotein B gene of the Korean EHV-4 isolate (K001) had 99.9% identity to 1942 strain (GenBank No. M26171). To author's knowledge, the report describes the first isolation and partial characterization of EHV-4 in Korea. The virus can be used for further study of EHV-4.

Salmonella Enteritidis is responsible for causing foodborne diseases upon consumption of egg products. While cases of S. Enteritidis isolation from eggs have been reported in other countries, no such cases have previously been reported in Korea. In this study, we report the first isolation and identification of S. Enteritidis from domestically distributed eggs in Korea. Eggs were collected from eight countrywide grocery stores during different seasons between 2011 and 2012. Egg contents and washing solution of egg shells were incubated in buffered peptone water, and the enriched broth was further enriched in tetrathionate broth and Rappaport-Vassiliadis. The secondary enriched broth was streaked on xylose lysine desoxycholate agar. The suspected colonies were confirmed to S. Enteritidis by a biochemical test, serotyping, and PCR test. Genetic relatedness among the isolates was analyzed using Diversilab Salmonella kit. Three strains of S. Enteritidis were isolated from egg contents and egg shells collected from grocery stores of the Eumseong-city in the fall of 2011. All three stains showed resistance to chloramphenicol, streptomycin, nalidixic acid, and ampicillin by the disk diffusion method. In addition, the isolates showed more than 99% DNA homology, indicating that they were presumably identical strains. Therefore, there is a requirement to monitor and control against S. Enteritidis from eggs in Korea.

Two species, $Penicillium$ $adametzioides$ and $Purpureocillium$ $lilacinum$, were isolated from decayed grapes (cv. Cheongsoo) in Korea. Each species was initially identified by phylogenetic analysis of a combined dataset of two genes. Internal transcribed spacer (ITS) and ${\beta}$-tubulin (BT2) genes were used for identification of $Penicillium$ $adametzioides$, and ITS and partial translation elongation factor 1-${\alpha}$ (TEF) genes were used for identification of $Purpureocillium$ $lilacinum$. Morphologically, they were found to be identical to previous descriptions. The two species presented here have not been previously reported in Korea.

데마슘과 오수생물인 Exserohilum rostratum 진균이 피부염에 걸린 2세의 암말 피부 병변으로부터 분리되었다 이 암말은 다수의 작고, 인설로 덮힌 불규칙한 모양의 백회색 탈모 병변을 목과 등에 나타내었다. 감염경로는 확인되지 않았으나 Exserohilum rostratum은 자연 상태에서 오수생물로써 증식한다. 저자들의 지식으로써는 피부병에 걸린 어린 말에서 Exserohilum rostratum의 분리는 새로운 숙주를 기록하는 것이다. 다양한 동물의 질병에서 Exserohilum rostratum의 역할을 조사해야 될 것을 제시하였다.