• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.107-116
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• 2006

Korean entomopathogenic nematode strain were evaluated against white grubs, Popillia quadriguttata, Ectinohoplia rufipes and Phyllopertha diversa in laboratory. In addition we examined the efficacy of entomopatogenic nematode, Heterorhabditis sp. KCTC 0991BP strain against white grubs in Seaside Golf Club in Gimpo, Gyeonggii and persistence of entomopatogenic nematode in fairway of Anyang Benest Golf Club in Gunpo, Gyeonggii. In laboratory Heterorhabditis bacteriophora Hamyang strain showed 95% mortality against Popillia quadriguttata. H. bacteriophora Hamyang strain and Heterorhabditis sp. KCTC 0991BP induced 80% mortality against 3rd instar of Ectinohoplia rufipes. However, the letter showed only 60% mortality against Phyllopertha diversa. White grub density was reduced to 39% by the application of Heterorhabditis sp. KCTC 0991BP at the rate of $2.24{\times}10^9$ infective juveniles $ha^{-1}$ compared with control in Seaside Golf Club. Heterorhabditis sp. KCTC 0991BP persisted for two months at $5{\sim}10$ cm soil depth but not persisted at $0{\sim}5$ cm soil depth for the same periods when applied at the rate of $2.47{\times}10^9$ infective juveniles $ha^{-1}$.

• Parasites, Hosts and Diseases
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• v.28 no.3
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• pp.161-174
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• 1990

The complete life cycle of Spirometra erinacei has been experimentally maintained in the laboratory. The cyclops were reared as the first intermediate host, and the tadpoles of Rana nigromaculata as the second intermediate host. ICR mice were used as another second host. The experimental definitive hosts were dogs and cats. Maturation and hatching of the eggs took 8 to 14 days by incubation at 29℃. The coracidium measured 43.8×36.9㎛. Mesocyclops leuckarti and Eucyclops serrulatus were susceptible to the coracidial infection. The procercoids older than 5 days in the cyclops had minute spines at the anterior end, calcium corpuscles in the body parenchyme and the cercomer at the posterior end. Procercoids 10 to 20 days old were infective to tadpoles, and 15 or 21 day old worms could infect the mice. The plerocercoids from the tadpoles at 15 days after experimental infection were pear-shaped and shorter than 1 mm in the length and were infective to mice. Fifteen to 18 days after experiMental inoculation of plerocercoids to dogs or cats, the adult worms began to produce eggs. One life cycle from egg to egg needed 48 to 67 days in the laboratory. The morphology of larval or adult worms was compatible with the description of Spirometra erinacei.

• Pediatric Infection and Vaccine
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• v.23 no.3
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• pp.209-216
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• 2016

Purpose: This study aimed to evaluate and compare the characteristics of infective endocarditis (IE) between children and adults with congenital heart disease (CHD) at a single tertiary care center. Methods: In this retrospective medical record review, we extracted the demographic characteristics, diagnostic variables, and outcomes of patients diagnosed with IE and CHD between 2000 and 2016. Results: We identified a total of 14 pediatric patients (nine male; median age at diagnosis, 3 years). Of the 14 patients, six had a history of previous open heart surgery, while four had undergone tetralogy of Fallot repair, with transannular patch or Rastelli procedure. Among the 10 children with positive blood cultures, the most common isolated organism was Staphylococcus spp. (8/10, 80%). Eleven adult patients had IE and CHD. Among the adult patients, only four were diagnosed with CHD before IE, and ventricular septal defect was the most common CHD. The most common isolated organism was Streptococcus spp. (6/11, 55%). Compared with adult patients, pediatric patients had a higher incidence of previously diagnosed CHD (P=0.001), with Staphylococcus spp. as the causative organism (P=0.027). The median duration between the onset of symptoms and diagnosis of IE was 9 days in children and 42 days in adults (P=0.012). Conclusions: Significant differences with regard to the diagnosis and progress of IE were observed between children and adults. Age-adjusted and systematic reassessment may be necessary for the diagnosis and management of IE.

• Biomedical Science Letters
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• v.11 no.2
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• pp.153-163
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• 2005

To clarify the species validity of the genus Spirometra, the biological characteristics of Spirometra erinacei and S. mansonoides by developmental stages were compared. Their experimental life cycles were maintained under the same laboratory conditions, and the biological characteristics were experimentally observed in vivo and in vitro conditions. Eggs of S. erinacei and S. mansonoides were $59.6\pm35.6{\mu}m\;and\;61.4\pm35.8{\mu}m$ in each average size. Both of them became fully matured and hatched in 8 days after incubation at $29^{\circ}C$. The coracidium of S. erinacei was $43.6\times35.8{\mu}m$ in average size, and retained a oncosphere of $39.3\times31.0{\mu}m$. That of S. mansonoides was $43.0\times36.3{\mu}m$ in average size, and retained a oncosphere of $38.3\times30.8{\mu}m$. Procercoids of S. erinacei were somewhat larger than those of S. mansonoides. Both species of procercoids older than 7 days in cyclops had minute spines at the anterior end, calcium corpuscles in the parenchyme and a cercomer at the posterior end. The procercoids older than 4 days in cyclops were infective to tadpoles. The procercoids older than 8 days revealed the infectivity to mice. Plerocercoids of S. erinacei were somewhat lager than those of S. mansonoides when they were compared by age of worms in tadpoles. Both species of plerocercoids older than 5 days were infective to mice. Among 138 plerocercoids of S. erinacei recovered from the experimental mice, $55(39.9\%)$ were detected in the neck portion, $35 (25.4\%)$ in the back portion, $25(18.1\%)$ in the anterior legs, and $23 (16.7\%)$ were found in the abdomen. In case of S. mansonoides plerocercoids, $42.0\%$ were found in the neck portion, $23.8\%$ in the back portion, $14.4\%$ in the abdomen, $13.3\%$ in the anterior legs, and $6.1\%$ were found in the posterior legs. From the above results, it was confirmed that the biological characteristics of S. erinacei and S. mansonoides are almost same when their life cycles are mainteined under the same laboratory condition. Accordingly, these findings suggest that S. erinacei and S. mansonoides may be the same species.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.335-343
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• 2006

Five strains of Korean entomopathogenic nematodes(EPN), steinernematids and heterorhabditids(Steinernama carpocapsae GSN1, Steinernema sp. GSNUS-10, Steinernama sp. GSNUS-14, Heterorhabditis bacteriophora Hamyang, Heterorhabditis sp. GSNUH-1) were evaluated and tried in petri dish, pot, and vegetable greenhouses for environmentally friendly control of beet armyworm, Spodoptera exigua. $LC_{50}$ values of five EPN strains against beet armyworm was different depending on nematode strain and beet armyworm instar. $LC_{50}$ value of Steinernema carpocapse GSN1(GSN1) was 3.8-5.1 infective juveniles(Ijs) in 2nd to 4th instars of beet armyworm. Pathogenicity of five EPN strains against beet armyworm different in nematode strain, concentration, application times, and vegetable species in pot and greenhouse. Steinernema spp. was more effective than Heterorhabditis spp. against beet armyworm. Two or three times of applications of EPN were found to be effective regardless of nematode strain and concentration in pot and greenhouse. ENP showed different reactions on vegetable species. Efficacy of EPN was higher on Chinese cabbage than that on cabbage and kale. GSN1 was one of the most effective nematodes and 100,000 infective juveniles per $m^2$(720,000 Ijs/$7.2m^2=1{\times}10^9$Ijs/ha) resulted in higher mortality in greenhouse.

• International Journal of Oral Biology
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• v.48 no.2
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• pp.9-18
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• 2023

The rapid detection of bacteria in the oral cavity, its species identification, and bacterial count determination are important to diagnose oral diseases caused by pathogenic bacteria. The existing clinical microbial diagnosis methods are time-consuming as they involve observing patients' samples under a microscope or culturing and confirming bacteria using polymerase chain reaction (PCR) kits, making the process complex. Therefore, it is required to analyze the development status of substances and systems that can rapidly detect and analyze pathogenic microorganisms in the oral cavity. With research advancements, a close relationship between oral and systemic diseases has been identified, making it crucial to identify the changes in the oral cavity bacterial composition. Additionally, an early and accurate diagnosis is essential for better prognosis in periodontal disease. However, most periodontal disease-causing pathogens are anaerobic bacteria, which are difficult to identify using conventional bacterial culture methods. Further, the existing PCR method takes a long time to detect and involves complicated stages. Therefore, to address these challenges, the concept of point-of-care (PoC) has emerged, leading to the study and implementation of various chair-side test methods. This study aims to investigate the different PoC diagnostic methods introduced thus far for identifying pathogenic microorganisms in the oral cavity. These are classified into three categories: 1) microbiological tests, 2) microchemical tests, and 3) genetic tests. The microbiological tests are used to determine the presence or absence of representative causative bacteria of periodontal diseases, such as A. actinomycetemcomitans, P. gingivalis, P. intermedia, and T. denticola. However, the quantitative analysis remains impossible, and detecting pathogens other than the specific ones is challenging. The microchemical tests determine the activity of inflammation or disease by measuring the levels of biomarkers present in the oral cavity. Although this diagnostic method is based on increase in the specific biomarkers proportional to inflammation or disease progression in the oral cavity, its commercialization is limited due to low sensitivity and specificity. The genetic tests are based on the concept that differences in disease vulnerability and treatment response are caused by the patient's DNA predisposition. Specifically, the IL-1 gene is used in such tests. PoC diagnostic methods developed to date serve as supplementary diagnostic methods and tools for patient education, in addition to existing diagnostic methods, although they have limitations in diagnosing oral diseases alone. Research on various PoC test methods that can analyze and manage the oral cavity bacterial composition is expected to become more active, aligning with the shift from treatment-oriented to prevention-oriented approaches in healthcare.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.644-648
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• 2001

The biological control potential of entomopathogenic nematodes (EPN) can be enhanced by improved culture efficiency. Optimization of the media is a key factor for improving in vitro mass production of entomopathogenic nematodes. This study reports the effect of medium concentration. The medium is a combination of carbohydrates, lipids, proteins, sats, and growth factors, on the growth of Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus liminescens. The overall optimal medium concentration for nematode recovery, hermaphrodite size, bacterial mass, infective juveniles (IJs) yield, and doubling time was 84 g/l. At this concentration rate, the doubling time of IJs production and the biomass of symbiotic bacteria was 1.6 days and 12.8 g/l, respectively. The maximum yield of $2.4{\times}{10^5}IJs/ml$ was attained within a one-generation cycle (eight days). The yield coefficient was $2.8{\times}{10^6}$ IJs/g medium, and the maximum productivity was $3.1{\times}{10^7}$ IJs per day. Medium concentration affected two independent factors, recovery and hermaphrodite size, which in turn influenced the final yield.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1729-1734
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• 2008

Chitosan, a cationic polysaccharide, has been widely used as a dietary supplement and in a variety of pharmacological and biomedical applications. The antifungal activity and mechanism of action of low molecular weight water-soluble chitosan (LMWS-chitosan) were studied in fungal cells and vesicles containing various compositions of fungal lipids. LMWS-chitosan showed strong antifungal activity against various pathogenic yeasts and hyphae-forming fungi but no hemolytic activity or cytotoxicity against mammalian cells. The degree of calcein leakage was assessed on the basis of lipid composition (PC/CH; 10:1, w/w). Our result showing that LMWS-chitosan interacts with liposomes demonstrated that chitosan induces leakage from zwitterionic lipid vesicles. Confocal microscopy revealed that LMWS-chitosan was located in the plasma membrane. Finally, scanning electron microscopy revealed that LMWS-chitosan causes significant morphological changes on fungal surfaces. Its potent antibiotic activity suggests that LMWS-chitosan is an excellent candidate as a lead compound for the development of novel anti-infective agents.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.296-301
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• 2008

Actinomyces is a part of the normal oral flora, but under certain circumstances it may become pathogenic. Actinomycosis is a chronic granulomatous infective disease caused by microaerophilic Gram-positive bacteria of the genus actinomyces. It can involve almost any system, but principally affects the head and neck. Because the lesions in the submandibular region and the angle of the jaw give the face a swollen, indurated appearance, actinomycosis of mandible can be easily misdiagnosed in its acute or early state of infection. In these cases the disease usually presented as a swelling suggestive of an abscess or mimicking a neoplasm. The yield from standard cultures was poor and repeated sampling and anaerobic culture may be needed to obtain a positive culture. So actinomycosis should always be considered in a differential diagnosis of all infections of the cervicofacial area. Diagnosis of actinomycosis is made based on the histopathology, the clinical presentation and past dental history. We experienced a case of actinomycosis in the masseter muscle and present the case with review of literature.

• Korean Journal of Veterinary Research
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• v.21 no.2
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• pp.161-165
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• 1981

A total of 210 dairy cows of Seongwhan area were epidemiologically investigated for mastitis by Milk Quality Test(MQT) method. Milk samples from cows infected with mastitis were also bacteriologically studied. Seventy four (42.5%) of 174 dairy cows were positive for mastitis and fifty nine (79.7%) among them were infected with subclinical mastitis and fifteen (20.3%) were clinical mastitis. High infective rate were shown on August (48.7%) and July (45.7%) and it was lowered on December (35.8%). The incidence rate of subclinical mastitis for herd shown tendency of increase at the barn in which located on lower place (30.7~43.9%), whereas, the barn in which was on higher place and with bucket type milking system shown tendency of decrease causative organisms. A total of 230 strains of etiological agents were isolated from 578 infected duarters which shown MQT score (+) or more. The relevant causative organisms isolated in this study were Staphylococcus aureus (18.3%), Staphylococcus epidermidis (16.9%), fungi (16.5%), Pseudomonas aeruginosa (15.2%), Escherichia coli (7.8%) and Serratia marcescens (2.27), respectively.