Purpose: This study aims to identify the degree of intention to hand hygiene and hand hygiene behavior in new nurses based on education experience on infection control. Method: The participants comprised 108 new nurses working in a general hospital in S city, Korea. Data were collected from September to December, 2020. Data were analyzed using descriptive statistics, independent t-test, analysis of variance (ANOVA), and Pearson correlation with SPSS 26.0 program. Results: There were statistically significant differences in intention to hand hygiene (F=3.39, p=.021) and hand hygiene behavior (F=3.33, p=.022) depending on education experience related to infection control during undergraduate courses. Hand hygiene intention (F=4.41, p=.008) and hand hygiene behavior (F=4.13, p=.008) showed statistically significant differences depending on educational satisfaction with infection control during undergraduate courses. There were significant positive correlations between intention to hand hygiene and hand hygiene behavior (r=.21, p=.026). Conclusion: This suggests that education in infection control can reinforce intention to hand hygiene and hand hygiene behavior in new nurses.

Purpose: The purpose of this study was to understand in-depth experiences of role conflict among infection control nurses’ (ICNs) in terms of the gaps between the role expectations and actual roles. Methods: This study was a qualitative study to explore and describe the implications of role conflict experiences of ICNs through a phenomenological approach. One-on-one in-depth interviews were conducted with ICNs who worked as full-time for more than three years in the infection control department, and the results were analyzed using Colaizzi’s (1978) phenomenological method. Results: Topics brought up by the participants were categorized into five themes. The themes included "lack of awareness of infection control", "psychological burden of professional competence", "infectious control not being accepted due to different management and operational goals", "unrelentingly overworked", "shadow labor without adequate compensation", and "The process of earning mutual trust". Conclusion: In order to resolve the role conflict of ICNs, it is necessary to establish a career management system for ICNs and to have an appropriate compensation system.

The infection of marine diatom Coscinodiscus wailesii by a parasitic protist from the Yongho Bay of Busan, Korea was observed during the diatom bloom events in 2017 through 2018. The morphological and molecular features suggested that the parasitic nanoflagellate Pirsonia diadema was responsible for the infection. During the study period, the parasite prevalence ranged from 0.3% to 3.3%, and infected C. wailesii cells were observed only at surface seawater temperatures ranging between 10.9 and 19.9°C, although the host population appeared at temperatures above 25°C. The parasite and host system was successfully established as cultures. Using the cultures, we determined the morphological features over the infection cycle, parasite generation time, parasite prevalence as a function of inoculum size, and zoospore infectivity and survival time. The diatom C. wailesii was readily infected by the parasite P. diadema, with a parasite prevalence reaching up to 100% and a zoospore to host inoculum ratio above 20 : 1. The survival and infectivity of the parasite zoospores decreased with age. While the zoospores could survive up to 88 hours, they quickly lost their ability to infect after 48 hours. These results could lead to a better understanding of the biology and ecology of the parasitoid infecting the giant-sized diatoms in coastal waters.

Botrytis cinerea is a necrotrophic pathogen that significantly reduced the postharvest quality and longevity of cut roses. The aim of this study was to examine the effects of nano silver, sodium hypochlorite (NaOCl), and salicylic acid on B. cinerea infection in cut rose flowers. Cut ‘Revival’ roses were treated with nano silver, NaOCl, salicylic acid, and distilled water, and simultaneously held in the solutions. Subsequently, the cut flowers were sprayed with B. cinerea solution and held under export conditions for 4 days. The results showed that nano silver was the most effective treatment in suppressing B. cinerea growth in cut roses during vase life. Nano silver effectively extended the vase life of cut roses by 2.3 days, compared with non-treated flowers. The addition of nano silver also enhanced water uptake and sustained the water balance and fresh weight of the cut rose flowers. Our results indicated that nano silver is an effective treatment solution to inhibit B. cinerea infection and improve postharvest quality and longevity of cut rose flowers for export.

만성 위염, 위암, 위궤양 등을 유발하는 Helicobacter pylori는 항생제의 부작용, 내성, 다제 내성균의 등장으로 항생제만으로 안전하게 치료하기는 어려운 실정이다. 안전하게 제균을 하기 위해 항생제를 대체할 수 있는 천연물 소재 치료제를 개발하기 위해 많은 연구들을 하고 있다. 선행 연구를 통해 in vitro 실험 H. pylori 항균 효과 평가를 통해 항균 효과가 우수한 추출물을 알아보고자 한다.

This study investigated the efficacy of four Brucella (B.) abortus recombinant proteins, namely adenylate kinase (Adk), nucleoside diphosphate kinase (Ndk), 50S ribosomal protein (L7/L12) and preprotein translocase subunit (SecB), as a combined subunit vaccine (CSV) against B. abortus infection in BALB/c mice. Immunoblotting assay showed that these four recombinant proteins as well as pcold-TF vector reacted individually with Brucella-positive serum, but not with Brucella-negative serum. The peripheral blood CD4+ T cell population was increased in CSV-immunized mice compared to PBS and pcold-TF vector groups. In addition, CSV and pcold-TF groups displayed induced IgG1 and IgG2a antibodies production compared to PBS and RB51 group, whereas IgG2a titer was higher than IgG1 titer in CSV group. The secretion profiles of IgG1 and IgG2a production together with an enhancement of CD4+ T cell population suggested that CSV did not only induce T helper 1 (Th1) T cell immunity but also humoral immunity. Therein, Th1 T cell immunity is more predominant in eliminating intracellular bacteria B. abortus. Furthermore, CSV immunization significantly reduced the bacterial burden in the spleen as well as the spleen weight in comparison to PBS and pcold-TF groups. Altogether, combination of these antigens could be potential to induce protective immunity against B. abortus infection in animals.

1. 경북지역 한지형 마늘 주산지인 의성지역을 중심으로 OYDV, LYSV, GCLV, SLV 그리고 Allexivirus를 진단한 결과, 모든 마늘잎의 시료가 한 가지 이상의 바이러스에 복합감염되어 있었다.. 2. 생장점 배양한 마늘은 1세대부터 3세대까지 OYDV와 SLV는 전혀 검출되지 않았다. 생장점 배양 마늘의 1세대는 GCLV 3.8%, Allexivirus 3.1%의 바이러스 감염률을 나타내었으며, 생장점 배양 마늘 2세대는 LYSV 3.4%, GCLV 21.7% 그리고 Allexivirus 10.0%를 나타내었다. 생장점 배양 마늘 3 세대는 GCLV 17.5%, Allexivirus 7.5%의 바이러스 감염률을 나타내었다. 3. 의성지역의 바이러스에 감염된 일반마늘 1통의 평균 무게는 29.3 g 이었으나, 생장점 배양에 의하여 증식된 2세대 마늘 1통의 평균 무게는 57.6 g, 3세대 마늘 1통의 평균 무게는 66.2 g 이었다.

항생제의 오남용은 세균의 항생제 내성을 증가시켜 세균감염에 의한 질병 치료에 어려움을 초래한다. 본 연구에서는 동애등애유충으로부터 분리된 펩타이드의 신장에서의 폐렴간균 감염 억제 효능을 관찰하였다. 마우스는 비강을 통해 폐렴간균을 감염시키고 1일 후 펩타이드를 마우스에 근육 주사로 투여하였다. 10일 후 마우스를 희생하여 신장에서 세균 감염증을 조사하였다. 대조군에 비해 펩티드를 투여한 마우스의 신장에서 세균 감염증상, 몸무게의 감소가 유의하게 억제되었고 생존률이 농도 의존적으로 증가하는 것으로 나타났다. 이러한 결과들은 동애등애로부터 분리된 펩타이드가 폐렴 간균의 신장에서의 감염증상을 억제할 수 있음을 보여준다. 따라서 동애등애로부터 분리된 펩타이드는 효과적인 항생제 개발에서 가능성 높은 후보물질이 될 수 있을 것이다.

Although canine brucellosis has been known to be an important re-emerging zoonosis, the pathophysiological mechanisms of Brucella canis infection remains clues to be solved. Different culture models, single and co-culture models, were constructed with canine epithelial cells, D17 and macrophage, DH82 to investigate the induction of immune responses in in vivo B. canis infection. Expression of genes related with induction of immune responses, Th1, Th2 and Th17, was compared in the two different models after the bacterial infection. In this study, expression of cytokine genes, IL-1β, IL-5, IL-6, IL-10, IL-23, and TNF-α was quantified in the DH82 at different time points using RT-qPCR in the two different culture systems after the infection. Cytokine genes related with Th1, IL-1β and TNF-α and Th17, IL-6 and IL-23 were expressed with time-dependent manners in the both systems (p<0.05). However, increase of Th2-related cytokine genes expression was not detectable in the both systems by comparison with control. The expression of Th1 and Th17 related cytokine genes was earlier in single cell culture than those in co-culture model (p<0.05). In general, amounts of the expressed genes were shown higher in single cell model than those in co-culture models. This study indicate that Th1 and Th17-associated immune responses are central to B. canis infection in dogs. In addition, it suggests a specific role of epithelial cells in the B. canis infection in vivo, which should resolved in the further study.

Brucellosis is the most common zoonosis worldwide, which is caused by Brucella spp. In humans, it can be mainly occurred by direct contact with infected animals or consumption of contaminated dairy products. This study focused on human brucellosis caused by B. melitensis discovered from Chinese worker in Korea in 2015. We investigated molecular epidemiological evidence to find the infection source. We first performed several PCR methods including 16S rRNA PCR, multiplex PCR and real-time PCR to identify Brucella species. We also conducted MLVA typing for epidemiological trace-back analysis. The isolate from the patient was confirmed to B. melitensis through Brucella-specific PCR. In clustering analysis with B. melitensis from foreign countries, this human isolate was correlated with B. melitensis isolates from humans and sheep in China by 99.9% similarity. Thus, we assumed the brucellosis patient has been already infected in China followed by migration to Korea according to molecular epidemiological analysis with history evidence. Moreover, we suggest it needs to take measures to reduce the risk for intercountry transmission of brucellosis due to the influx of infected people from abroad.

Various viral and bacterial pathogens interact with environmental factors to cause diarrhea in piglets. Enterococcus spp. are Gram-positive anaerobic bacteria that are commonly found in the gastrointestinal tract of several animal species, including pigs. Enterococcus spp. have been reported to infect several animal species as a pathogen. However, gastrointestinal infection by Enterococcus hirae is rare in pigs; only a few cases have been reported worldwide. Four piglets with diarrhea were examined in the diagnostic laboratory of Optipharm Inc. (Cheongju, Korea). During the initial post-mortem examination, no disease lesions were observed. Upon microscopic examination, we found numerous Gram-positive cocci that were adhered to epithelial villi in the jejunum and ileum. However, the villi did not exhibit significant structural damage. Cultured bacteria were identified as E. hirae using the VITEK 2 system and polymerase chain reaction (PCR). Using PCR, we also confirmed that viruses and protozoa that can potentially infect piglet intestines were absent. In antibiotic susceptibility test, the bacteria were resistant to most types of antibiotics. This study presents rare cases of E. hirae infection of the piglet small intestine, which can occur in association with diarrhea possibly by the continuous use of antibiotics.

Brain abscesses caused by odontogenic infection are a rare and life-threatening condition. When dental patients show neurological symptoms such as decreased consciousness, a brain abscess should be considered as a possible diagnosis. We reported that a 65-year-old man visited the emergency room because of left facial edema, high fever, limitation of mouth opening and decreased consciousness. CT, bone scan, and microbiologic examination revealed that the brain abscess originated from left mandibular osteomyelitis with an apical lesion in tooth #36. It was hard to diagnose the location of odontogenic infection. Because there were no evidence of submandibular abscess which is a common path of mandibular posterior infection, early diagnosis was difficult. MRI and radiographs such as facial CT and brain CT revealed procedure that inflammatory findings progressed through the coronoid process, the temporal space, into the subdural space. We compared the present case to previous cases, articles published after the year 2000 in Korea and abroad were investigated. The patient was treated successfully with extraction of causative teeth, drainage surgery, intravenous antibiotics by collaboration between the department of oral maxillofacial surgery and neurosurgery. It is difficult to diagnose brain abscess because central nervous system can be infected by various pathway. As shown in this case, patients with a brain abscess caused by a dental infection should be diagnosed and treated with a multidisciplinary approach.

BALB/c mice were vaccinated with Brucella (B.) abortus recombinant protein L27 (50S ribosomal protein L27) cloned into a pMal vector system. L27 was induced, purified and injected intraperitoneally (IP). Mice were vaccinated on 0-, 15- and 35-day. Serum cytokines were evaluated on 36- and 49-day from first vaccination. Mice were intraperitoneally infected with 5×104 CFU of virulent B. abortus 544 on day-50 and sacrificed after two weeks from infection. Bacterial burden from the spleen was quantified and showed a 0.7- and 0.9-log reduction in vaccinated mice in comparison to PBS and MBP (maltose binding protein) groups respectively. Cytokines in the serum demonstrated increased interferon-gamma (IFN-γ) and other pro-inflammatory cytokines such as macrophage chemoattractant protein-1 (MCP-1) and interleukin 6 (IL-6). On the other hand, interleukin 10 (IL-10) was attenuated in the sera of vaccinated mice. This cytokine profile is indicative of a cell-mediated type of immune response which is favorable for the eradication of intracellular infections. The current study showed the potential of another B. abortus ribosomal protein in inducing protective immunity against B. abortus infection.

We studied the infection rate of and various metacercariocidal approaches to controlling Gymnophalloides seoi for prevention of human infection in cultured and natural oysters in Korea. The selected survey areas were Aphae-do (Shinan-gun, Jeollanam-do), which is an endemic area for G. seoi, and Tongyeong (Geonsangnam-do), which is the main production area of oysters in Korea. In the Tongyeong area, the metacercariae of G. seoi were not detected in cultured oysters (0/201) or wild oysters (0/134). Seventy-two G. seoi metacercariae were observed in 33 of 265 natural oysters collected from Aphae-do; however, metacercariae were not detected in the cultured oysters (0/1101) purchased from the Daejeon Fish Market. To investigate the viability of G. seoi metacercariae, various metacercariocidal treatments were used with 3.5% saline and oyster juice used as positive controls. The metacercariae survived for 75.4 h in 3.5% saline and 112.6 h in oyster juice. After the metacercariocidal treatment, G. seoi metacercariae were survived for 13.29 min in tap water, < 20 sec in 4.3% vinegar, no effect in a rinse of the whole oyster body in 70°C water for 1 sec, but 1 sec in a rinse of the whole oyster body in 90°C water for 1 sec. The greatest metacercariocidal effect on G. seoi was from rinsing oysters in 90°C water followed by those from treatment with 20% ethyl alcohol, 4.3% vinegar, and tap water. However, we suggest that the most actual prevention to G. seoi human infection is rinsing the oysters with tap water for at least 30 min.