• Korean Journal of Pharmacognosy
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• v.47 no.2
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• pp.122-127
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• 2016

Methicillin-Resistant Staphylococcus aureus(MRSA) is a multidrug-resistant(MDR) strain. (+)-Usnic acid(UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against 17 different strains of the bacterium. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid(EDTA) was used. In the other hand, Sodium azide($NaN_3$) was used as inhibitors of ATPase. Against the 17 strains, the minimum inhibitory concentrations(MICs) of UA were in the range of $7.81-31.25{\mu}g/ml$. EDTA or $NaN_3$ cooperation against MRSA showed synergistic activity on cell wall. UA and in combination with EDTA and $NaN_3$ could lead to the development of new combination antibiotics against MRSA infection.

• Korean Journal of Veterinary Research
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• v.55 no.2
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• pp.117-123
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• 2015

Necrotic enteritis (NE) caused by Clostridium (C.) perfringens commonly occurs in domestic broiler farms since antibiotic supplementation in poultry feed has been banned. We evaluated the antibacterial activities of medicinal plant extracts against C. perfringens isolates to select alternative compounds for preventing NE. We compared antibacterial activities using two methods and evaluated susceptibilities of the isolates based on minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Two (Fraxinus rhynchophylla Hance [FRH] and Geranium koreanum Kom. [GKK]) of the 30 plant extracts had potent antibacterial activities against C. perfringens ATCC 13124 in two assays. The MIC values for FRH and GKK against 20 C. perfringens isolates were $128{\sim}256{\mu}g/mL$ and $32{\sim}128{\mu}g/mL$, respectively. The geometric MIC mean values for the two extracts were $147.2{\mu}g/mL$ and $68.8{\mu}g/mL$, respectively. The MBCs for the two extracts against the same strains were $1,024{\sim}2,048{\mu}g/mL$ and $256{\sim}1,024{\mu}g/mL$, respectively. The geometric mean MIC and MBC for GKK were about two-fold lower than those of FRH. The modified spot-on-lawn assay may be useful for measuring primary antibacterial potential. FRH and GKK are expected to be used as feed additives to prevent or treat NE in veterinary practice.

• The Journal of the Korean Society for Microbiology
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• v.13 no.1
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• pp.7-16
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• 1978

One hundred and three clinical isolates of enterococci were examined for susceptibility to 8 antibiotics, and transferability and transfer frequency of R plasmid. Ampicillin was the most active, followed in decreasing order by rifampin, amikacin and chloramphenicol, and tetracycline. High-level resistance(${\geq}2,000{\mu}g/ml$) to kanamycin, streptomycin, and gentamicin, known as the most active of the aminoglycosides to enterococcus, was present in 26.2%, 21.4%, and 18.3% of the isolates, respectively. In the drug susceptibility of the species, S. zymogenes was the most resistant and S. durans was the most sensitive to tested antibiotics. We could observed the transferability of enterococcal R plasmid in mixed culture: among the 28 strains which showed multiple drug resistance, 17 strains transferred all or part of their resistance with $2{\times}10^{-4}-2{\times}10^{-6}%$ of transfer frequency to a plasmid-free recipient, S. faecalis strain JH 2-2.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.199-204
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• 2006

Streptococcosis of olive flounder(Paralichthys olivaceus) is an important bacterial disease in Jeju island. In this study, we investigated monthly infection pattern of this disease in different size of the flounder fish. Even though the disease occurred throughout the year, the infection ratio was relatively higher in the months with warm water season. The infection was more prevalent in adult flounder over 30 cm total length compare to these of small size fish. Two infectious species of streptococcosis pathogens were detected by multiplex PCR assay. Detection ratios of Streptococcus iniae and S. parauberis reached up to 46% and 54%, respectively, from June 2003 to May 2005 in Jeju island. S. iniae occurred intensively from September to October, whereas S. parauberis reported from March to May. S. iniae and S. parauberis infections of cultured flounder share some common features, but clinical findings showed considerable differences between two diseases. Distended abdomen, protruded anus and ascitic fluid in the peritoneal cavity are evident lesions detected in S. iniae infection, whereas, flounders infected by S. parauberis showed prominent lesions such as darkened surface and haemorrhaging in the non-ocular side. Both streptococcosis pathogens were sensitive to antibiotics, such as ampicillin and amoxicillin. However, S. iniae strains were more sensitive to doxycycline, erythromycin and oxytetracycline than S. parauberis strains.

• Korean Journal of Veterinary Service
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• v.44 no.3
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• pp.169-174
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• 2021

Mastitis is an inflammatory condition of the mammary gland, most often caused by bacterial infections, resulting in significant economic losses to the dairy industry. Antimicrobial resistance has been of great concern because of the extensive clinical use of antibiotics. For this reason, the development of new compounds as an alternative treatment to bovine mastitis is needed. Bee venom has been widely used as an oriental treatment for several inflammatory diseases and bacterial infections. The aim of the present study was to evaluate the antimicrobial activity of bee venom on bacteria isolated from bovine mastitis. A total of 107 isolates from bovine mastitic milk samples collected in 2019 and 2020 in Jeonbuk province. All bacterial isolates were tested for susceptibility to bee venom of the honey bee (Apis mellifera). In order to obtain comprehensive antibacterial activities of the bee venom, we measured the minimal inhibitory concentration (MIC) of the bee venom against bacterial strains. Bee venom showed significant inhibition of bacterial growth of Gram-negative bacteria Citrobacter spp., Escherchia coli, Klebsiella spp., Pseudomonas spp., Serratia spp. and Raoultella with MIC values of 96, 81, 72, 230, and 85 ㎍/mL, respectively, and Gram-positive bacterial Enterococcus spp., Staphylococcus spp. and Streptococcus spp. with MIC values of 29, 21 and 16 ㎍/mL, respectively. The results indicated that the MIC values were different depending on the bacterial strains, and those of Gram-positive bacteria were lower than those of Gram-negative bacteria for bee venom. These findings suggested that bee venom could be an effective antimicrobial treatment for bovine mastitis; however, further research is necessary to evaluate the mechanism underlying the antimicrobial action, its effectiveness/safety in vivo and effective application for therapeutic use.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.74-81
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• 2016

Ureaplasma species can normally colonize in the bodies of healthy individuals. Their colonization is associated with various diseases including non-gonococcal urethritis, chorioamnionitis, neonatal meningitis, and prematurity. In 2012, the sum of the resistant and intermediate resistant rates of Ureaplasma spp. to ofloxacin and ciprofloxacin was 66.08% and 92.69%, respectively. DNA point mutations in the genes encoding DNA gyrase (topoisomerase II) and topoisomerase IV are commonly responsible for fluoroquinolone resistance. Each enzyme is composed of two subunits encoded by gyrA and gyrB genes for DNA gyrase and parC and parE genes for topoisomerase IV. In the current study, these genes were sequenced in order to determine the role of amino acid substitutions in Ureaplasma spp. clinical isolates. From December 2012 to May 2013, we examined mutation patterns of the quinolone resistance-determining region (QRDR) in Ureaplasma spp. DNA sequences in the QRDR region of Ureaplasma clinical isolates were compared with those of reference strains including U. urealyticum serovar 8 (ATCC 27618) and U. parvum serovar 3 (ATCC 27815). Mutations were detected in all ofloxacin- and ciprofloxacin-resistant isolates, however no mutations were detected in drug-susceptible isolates. Most of the mutations related to fluoroquinolone resistance occurred in the parC gene, causing amino acid substitutions. Newly found amino acid substitutions in this study were Asn481Ser in GyrB; Phe149Leu, Asp150Met, Asp151Ile, and Ser152Val in ParC; and Pro446Ser and Arg448Lys in ParE. Continuous monitoring and accumulation of mutation data in fluoroquinolone-resistant Ureaplasma clinical isolates are essential to determining the tendency and to understanding the mechanisms underlying antimicrobial resistance.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.115-123
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• 2006

Purpose : We investigated whether there had been any change in the epidemiology of Streptococcus pneumoniae in Korea before and after introduction of heptavalent pneumococcal conjugate vaccine(PCV7). Methods : Between September 2001 and August 2006, clinical isolates were collected from patients with pneumococcal infection in Severance Hospital, Seoul, Korea. We analyzed trends in serotype distribution and antibiotic resistance before and after the introduction of PCV7. Results : There were 363 strains of Streptococcus pneumoniae isolated from clinical specimens; 143 before and 220 after PCV7 introduction. The predominant serotypes, in order of decreasing frequency, were 19F, 19A, 23F, 6B, 6A, 3, 9V, 14, 11A, 4, 29, and 18C; 152 isolates(41.9%) belonged to types included in PCV7. The proportion of clinical isolates that were nonsusceptible to penicillin increased from 58.8% in 2001 to 83.6% in 2006(P=0.046). There was no significant diminution in pneumococcal infection caused by vaccine serotypes after the introduction of PCV7. In children younger than age 2 years, the proportion of clinical isolates that were vaccine serotypes was higher than in persons older than age 15 years (59.3% vs 37.8%, P=0.004). Conclusions : There was no significant diminution in pneumococcal infection caused by vaccine serotypes after the introduction of PCV7, therefore more universal pneumococcal immunization program is recommended especially for children younger than age 2 years.

• Clinical and Experimental Pediatrics
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• v.49 no.12
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• pp.1287-1295
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• 2006

Purpose : The importance of staphylococcal infections in NICU has been emphasized in terms of increased resistant strains and increased incidence of morbidity and mortality. In this study, we inrestignted the clinical characteristics and risk factors for staphylococcal infections, and looked into sensitivity trends of antibiotics in the era of a high rate of methicillin-resistant staphylococcus aureus (MRSA) in our society. Methods : This study included 240 neonates with positive blood, urine and other sites cultures for staphylococci who were admitted to NICU of Hanil General Hospital and Kyunghee University Hospital from January 2000 to December 2004. The analyses included clinical characteristics of staphylococcal infections and the relationship of incidence rate among various factors, including invasive procedures. Results : For 5 years, 3,593 patients were hospitalized in the NICU and 7,481 specimens were cultured from blood, urine, and other sites. During the study period, staphylococci were isolated from 240 patients, of whom 88 patients had MRSA, 41 patients methcillin sensitive staphylococcus aureus (MSSA), 63 patients S. epidermidis, 48 patients coagulase-negative staphylococcus (CNS) except S. epidermidis infections. The risk factors associated with staphylococcal infections were less than 37 weeks of gestational age, less than 7 on a 5 minutes Apgar score, receiving TPN, applied mechanical ventilation, use of central venous catheters and other tubes. The sensitivity to vancomycin was 100 percent. A relatively high sensitivity against teicoplanin, trimethoprim-sulfamethoxazole, chloramphenicol, clindamycin and low sensitivity against gentamicin and erythromycin were shown. Conclusion : To reduce staphylococcal infections in NICU, we need to monitor and manage premature neonates from the beginning of the birth process and to avoid as many invasive procedures as possible in NICU. Considering MRSA, control of preceding factors and early use of appropriate antibiotics is expected to reduce the morbidity and mortality caused by MRSA infections.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1107-1115
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• 2005

Purpose : An outbreak of ESBL-producing Shigella sonnei enteritis was unprecedented not only in Korea but throughout the world in the past. We intended to devise a management guideline for ESBL-producing shigellosis based on analysis of clinical manifestations and response to therapy. Methods : We analyzed 103 patients who were admitted to the hospital with acute GI symptoms and were shown positive result for S. sonnei on stool culture. We performed sensitivity test to the antibiotics and DNA sequencing of ESBL gene in the isolated S. sonnei colonies. In addition, we retrospectively analyzed their clinical characteristics, laboratory results, and clinical and microbiological responses to the antibiotics. Results : Among the clinical manifestations, fever was the most frequent(96.1%), followed by diarrhea(93.2%), abdominal pain(76.7%), headache(71.8%), vomiting(65.0%), and nausea(41.7%). The fever was sustained for average of 2.0 days and diarrhea for 3.9 days. Watery diarrhea was the most common(69%) followed by mucoid(26%), and bloody stool(5%). On peripheral blood smear, leukocytosis was noted in 53.4% of patients, and 78.6% of patients tested positive for serum CRP response. On stool direct smear, 11.7% of patients showed more than 50 WBCs/HPF, and 9.7% of patients between 5 to 20 WBCs/HPF. Stool occult blood was positive in 71% of patients. Production of CTX-M-14 type ESBL was reported for all S. sonnei strains isolated from this outbreak. Microbiological eradication rates to various antibiotics were as follows : 100%(9/9) to ciprofloxacin, 100% 5/5) to azithromycin, 6.9%(5/72) to cefdinir, 0%(0/8) to ceftriaxone, 12.5%(1/8) to ceftizoxime, 0%(0/ 8) to TMP/SMX, 42.9%(3/7) to ampicillin/sulbactam, 20%(1/5) to amoxicillin/clavulanic acid, and 68.8 %(11/16) to imipenem/cilastatin. Conclusion : It is presumed that azithromycin can be an attractive option for the treatment of ESBL-producing S. sonnei enteritis in pediatric population, given its cost-effectiveness and safety. Although ciprofloxacin is another cost-effective agent, its use in pediatric population may be a bit too premature.

• Journal of Hospice and Palliative Care
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• v.1 no.1
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• pp.1-5
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• 1998

Grief is the ordinarily self-limited complex of symptoms and processes that constitute the acute reaction to a significant loss. And it is the reaction of the dying as well as the bereaved. Every culture has had its own ways of grief and mourning. The definition of healthy grief and mourning, in terms of both emotional expression and the length of time it should continue, mostly depend upon the type of culture as well as the type of religion. So the manner of grief and mourning greatly differs from culture to culture. In the most of the Asian countries, influenced by Confucianism, Taoism, and Buddhism, death is traditionally considered the most significant life cycle transition. In Chinese culture, many rituals have evolved to help family members deal with their loss, over the past five thousand years. Confucianism taught the virtues of filial piety and righteousness. These rules and many customs added since the time of Cofucius, have been loyally followed and practiced by many Asian people. However, Buddhists have different ideas. They believe in karma and reincarnation and in predetermination of one's present life by good or bad deeds in the present life and past lives. Display of uncontrollable emotion is not encouraged. Continuity of family relations after death is very important. The ancient practice of the ancestor worship is still followed in many Asian households. Many Buddhist do not practice ancestor worship; family members honor the deceased by placing a memorial plate in the temple for continued chanting purposes. The mourning rituals have been dramatically curtailed in the past 50 years. For example, political, social and economic forces have shaped the current mourning practices of Chinese in different countries. There are many clinical implications in helping Asian to deal better with the emotional strains of the experience of loss. The therapiest must respect the cultural framework through which the client perceives family losses.