• Journal of radiological science and technology
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• v.44 no.3
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• pp.231-237
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• 2021

The ongoing coronavirus disease 2019 (COVID-19) pandemic has highlighted the importance of hospital hygiene and infection control in hospital settings. To raise hygiene awareness among ultrasound technicians, we evaluated the hygiene status of an ultrasound room, in comparison with that of objects used in daily life. Using the swab method, the following surfaces were examined: eight surfaces in the ultrasound room including the ultrasound probes (convex, linear, sector, 3D), ultrasound track ball, ultrasound keyboard, ultrasound gel (sealed and in use) and pillow as well as four surfaces of everyday objects including subway handles, common computer keyboards, common computer mouse, and cell phones. The streak plate technique was used for inoculation into media, which was observed for the formation of bacterial colonies following incubation for 24 h. Six bacterial strains were detected from objects used in the ultrasound room, including methicillin-resistant Staphylococcus aureus. Four strains of bacteria were detected on surfaces of everyday objects. The equipment and accessories used in an ultrasound room can act as vehicles for infecting patients. Establishment of standardized hygiene protocols and periodic training of the staff are recommended to avoid cross-infection.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.1-14
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• 2022

Bacteria communicate with each other through an intricate communication mechanism known as quorum sensing (QS). QS regulates different behavioral aspects in bacteria, such as biofilm formation, sporulation, virulence gene expression, antibiotic production, and bioluminescence. Several different chemical signals and signal detection systems play vital roles in promoting highly efficient intra- and interspecies communication. Gram-negative bacteria coordinate gene regulation through the production of acyl homoserine lactones (AHLs). Gram-positive bacteria do not code for AHL production, while some gram-negative bacteria have an incomplete AHL-QS system. Despite this fact, these microbes can detect AHLs owing to the presence of LuxR solo receptors. Various studies have reported the role of AHLs in interspecies signaling. Moreover, as bacteria live in a polymicrobial community, the production of extracellular compounds to compete for resources is imperative. Thus, AHL-mediated signaling and inhibition are considered to affect virulence in bacteria. In the current review, we focus on the synthesis and regulation mechanisms of AHLs and highlight their role in interspecies bacterial signaling. Exploring interspecies bacterial signaling will further help us understand host-pathogen interactions, thereby contributing to the development of therapeutic strategies intended to target chronic polymicrobial infections.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.4
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• pp.322-328
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• 2005

Oral and maxillofacial infections are most commonly odontogenic in origin. The present study was implemented for patients with oral and maxillofacial infections in order to determine what differences were present in cultured bacteria, depending upon the different types of infection. For the present study, the epidemiological characteristics, the state of infection, and the results of the pus culture and antibiotic susceptibility tests were analyzed for the 159 cases where pus culture tests were performed. The patients were treated at the Oral and Maxillofacial Surgical Department of Chonnam National University Hospital during an 18-months period from March 2003 to August 2004. Among the total 159 pus culture specimens, bacteria were cultured in 111 cases (69.8%). In the 111 pus culture specimens, Streptococcus species, Neisseria species, and Staphylococcus species were cultured from 69 cases (51.1%), 21 cases (15.6%), and 15 cases (11.1%), respectively and were determined to be bacterial strains the predominant bacteria responsible for oral and maxillofacial infectious diseases. Twenty four cases (15.1%) among the 159 specimens showed mixed infections. The mostly isolated bacteria from each of the space abscess, dentoalveolar abscess, inflammatory cyst, and pericoronitis cases were the Viridans streptococci. There was little relevance between the type of infection and the type of cultured bacteria. Antibiotic susceptibility tests showed a high level of susceptibility to teicoplanin(100%), vancomycin(100%), chloramphenicol(96.4%), ofloxacin(88.3%), imipenem(83.3%), erythromycin(82.5%) and a low susceptibility to cefazolin(40.0%), oxacillin(44.7%), ampicillin(49.4%), penicillin(51.1%). These results indicate that there was no significant difference among the cultured bacteria depending on the type of infections and their susceptibility to cephalosporin and penicillin G was low.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.5
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• pp.474-484
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• 2018

Objective: The time to positivity (TTP) of blood culture reflects bacterial load and has been reported to be associated with outcome in bloodstream infections. This study was performed to evaluate the relationship between the TTP of blood culture and the mortality rates associated with sepsis and septic shock according to the site of infection. Methods: We performed a retrospective cohort study on patients with sepsis and septic shock. The rates of blood culture positivity and mortality as well as the relationship between the TTP and 28-day mortality rate were compared among patients with different sites of infection, such as the lungs, abdomen, urogenital tract, and other sites. Results: A total of 2,668 patients were included, and the overall mortality rate was 21.6%. The rates of blood culture positivity and mortality were different among the different infection sites. There was no relationship between the TTP and mortality rates of total, lung, and urogenital infections. Patients with abdominal infections showed a negative correlation between the TTP and 28-day mortality rate. In patients with abdominal infections, a TTP<20 hours was independently associated with 28-day mortality compared with patients with negative blood culture (hazard ratio, 1.73; 95% confidence interval, 1.16-2.58). However, there was no difference in mortality rates of patients with a $TTP{\geq}20$ hours and a negative blood culture. Conclusion: The shorter TTP in patients with abdominal infections in sepsis and septic shock was associated with a higher 28-day mortality rate.

• Clinical and Experimental Pediatrics
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• v.48 no.3
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• pp.251-259
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• 2005

Atopy is a highly prevalent and serious health problem. The prevalence and severity of asthma and allergic diseases have increased over recent decades, particularly in industrialized nations. Early life infections may protect against the development of atopy and allergic diseases like asthma. The inverse relationship between the incidence of atopy and childhood infections has led to the 'hygiene hypothesis', which suggests that diminished exposure to childhood infections in modern society has led to decreased Th1-type responses. Th1 and Th2 responses are counter-regulatory. Reduced Th1 may lead to enhanced Th2-type inflammation, which is important in promoting asthma and allergic disease via up-regulation of IL-4, IL-5, and IL-13. It is now widely accepted that altered regulation of Th2 responses(and possibly the balance between Th1 and Th2 responses) is an important factor in the development of atopy. CpG DNA represent a novel class of drugs with substantial immunomodulatory properties. CpG DNA contain unmethylated motifs centered on the CpG dinucleotides, like bacterial DNA. These CpG DNA promote Th1 and regulatory type immune responses and suppress Th2 responses. In murine studies, CpG DNA are effective in prevention and treatment of asthma and allergic diseases. CpG DNA are just beginning to be tested in human asthma. While its precise mechanisms continue to be fully studied, CpG DNA offers considerable promise as a novel treatment for atopic inflammation. It may prove to be an important disease modifying therapy, or even curative therapeutic agent for asthma and allergic diseases.

• IMMUNE NETWORK
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• v.9 no.2
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• pp.46-52
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• 2009

Although tuberculosis poses a significant health threat to the global population, it is a challenge to develop new and effective therapeutic strategies. Nitric oxide (NO) and inducible NO synthase (iNOS) are important in innate immune responses to various intracellular bacterial infections, including mycobacterial infections. It is generally recognized that reactive nitrogen intermediates play an effective role in host defense mechanisms against tuberculosis. In a murine model of tuberculosis, NO plays a crucial role in antimycobacterial activity; however, it is controversial whether NO is critically involved in host defense against Mycobacterium tuberculosis in humans. Here, we review the roles of NO in host defense against murine and human tuberculosis. We also discuss the specific roles of NO in the central nervous system and lung epithelial cells during mycobacterial infection. A greater understanding of these defense mechanisms in human tuberculosis will aid in the development of new strategies for the treatment of disease.

• Childhood Kidney Diseases
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• v.24 no.1
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• pp.27-35
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• 2020

Purpose: Urinary tract infections (UTIs) are the most common and serious bacterial infections in children. Therefore, early diagnosis of vesicoureteral reflux (VUR) for treatment planning and the identification of noninvasive markers that can predict renal injury are important in patients with UTIs. We analyzed the clinical features of pediatric UTIs commonly encountered by general practitioners and reinterpreted the blood tests and imaging findings to identify the important clinical predictive markers of VUR in order to selectively perform VCUG. Methods: This retrospective study was performed among 183 children diagnosed with a UTI or acute pyelonephritis. Results: The most significant predictor of high grade and bilateral VUR identified using area under the curve analyses was hydronephrosis on kidney ultrasound images with renal cortical defects on dimercaptosuccinic acid (DMSA) kidney scan simultaneously, followed by hydronephrosis only on kidney ultrasound. Conclusion: The presence of hydronephrosis on kidney ultrasound images or cortical defects or asymmetric kidneys on the DMSA kidney scans can be predictive markers of VUR, reducing the need for VCUG. Our study can thus help minimize the exposure to radiation among patients through selective VCUG.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.6
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• pp.886-893
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• 2012

Methicillin-Resistant Staphylococcus aureus (MRSA) is a cephalosporin and beta-lactam antibiotic-resistant strain. In most cases, MRSA is spread from infected patients and infection rates are growing increasingly. Furthermore, increased resistance to antibiotics is causing serious problems in the world. Staphylococcus aureus is responsible for both nosocomial and community-based infections that range from relatively minor skin and soft tissue infections to life-threatening systemic infections. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. In this study, we investigated antimicrobial activity of oriental medicine prescription against MRSA. The minimum inhibitory concentration (MIC) of Sohamhyung-tang water extract against S. aureus strains ranged from 500 to 2,000 ${\mu}g/mL$, so we have it confirmed that a strong antibacterial effect. Also, the combinations of Sohamhyung-tang water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Sohamhyung-tang water extract against MRSA have antibacterial activity, it has potential as alternatives to antibiotic agent. We suggest that the Sohamhyung-tang water extract lead the treatment of bacterial infection to solve the resistance and remaining side-effect problems that are the major weak points of traditional antibiotics.

• Pediatric Infection and Vaccine
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• v.26 no.3
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• pp.188-193
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• 2019

Since the implementation of conjugate Haemophilus influenzae serotype b (Hib) vaccine, the rate of infections caused by Hib has dramatically decreased, and the proportion of infections caused by non-type b H. influenzae has increased. Cerebral venous sinus thrombosis (CVST) is rare; however, it should be considered as a potential complication of bacterial meningitis. Herein, we report about a child who developed CVST after being diagnosed with H. influenzae serotype f meningitis.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.1 no.1
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• pp.52-57
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• 2020

Bacterial symbionts are common across insects, including ants (Hymenoptera: Formicidae). Reproduction-manipulating endosymbionts, such as Wolbachia, Spiroplasma, Rickettsia, and Cardinium, are closely associated with many aspects of host-insect life. In addition, phage WO plays an essential role in the phenotypic effects of Wolbachia. Although endosymbionts are possible biological control agents, there is a lack of knowledge of their rate of infection of ants in Korea. We tested a range of Korean ant species for the presence of Wolbachia, Spiroplasma, Rickettsia, Cardinium, and phage WO by extracting DNA from the ants and using specific primer sets to test the status of infections. In addition, the mitochondrial cytochrome c oxidase I (COI) gene of the host ants was amplified to confirm the molecular identification and phylogenetic relationship between the hosts. We found that infection with Wolbachia (29.6% of species) is relatively common when compared with that of other endosymbionts. Only one species was infected with Spiroplasma. Infection with Rickettsia and Cardinium was not detected in the examined ants. Most Wolbachia in ants were infected with phage WO. Although the phenotypic effects of endosymbionts in ants are still unknown, this first survey of endosymbionts in Korea is the first step toward the use of reproduction-manipulating endosymbionts.