• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.795-803
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• 2024

Microorganisms usually coexist as a multifaceted polymicrobial community in the natural habitats and at mucosal sites of the human body. Two opportunistic human pathogens, Pseudomonas aeruginosa and Staphylococcus aureus commonly coexist in the bacterial infections for hospitalized and/or immunocompromised patients. Here, we observed that autolysis of the P. aeruginosa quorum-sensing (QS) mutant (lasRmvfR) was suppressed by the presence of the S. aureus cells in vitro. The QS mutant still displayed killing against S. aureus cells, suggesting the link between the S. aureus-killing activity and the autolysis suppression. Independent screens of the P. aeruginosa transposon mutants defective in the S. aureus-killing and the S. aureus transposon mutants devoid of the autolysis suppression revealed the genetic link between both phenotypes, suggesting that the iron-dependent metabolism involving S. aureus exoproteins might be central to both phenotypes. The autolysis was suppressed by iron treatment as well. These results suggest that the interaction between P. aeruginosa and S. aureus might be governed by mechanisms that necessitate the QS circuitry as well as the metabolism involving the extracellular iron resources during the polymicrobial infections in the human airway.

• Parasites, Hosts and Diseases
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• v.53 no.6
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• pp.705-712
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• 2015

Intestinal parasitic infections are one of the major causes of diarrhea in human immunodeficiency virus (HIV) seropositive individuals. Antiretroviral therapy has markedly reduced the incidence of many opportunistic infections, but parasite-related diarrhea still remains frequent and often underestimated especially in developing countries. The present hospital-based study was conducted to determine the spectrum of intestinal parasitosis in adult HIV/AIDS (acquired immunodeficiency syndrome) patients with or without diarrhea with the levels of $CD4^+$ T-cell counts. A total of 400 individuals were enrolled and were screened for intestinal parasitosis. Of these study population, 200 were HIV seropositives, and the remaining 200 were HIV uninfected individuals with or without diarrhea. Intestinal parasites were identified by using microscopy as well as PCR assay. A total of 130 (32.5%) out of 400 patients were positive for any kinds of intestinal parasites. The cumulative number of parasite positive patients was 152 due to multiple infections. A significant association of Cryptosporidium (P<0.001) was detected among individuals with $CD4^+$ T-cell counts less than $200cells/{\mu}l$.

• Journal of Applied Biological Chemistry
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• v.53 no.3
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• pp.184-188
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• 2010

Effect of the plant essential oils on the growth of Malassezia pachydermatis was evaluated and the essential oils of Ocimum basilicum L., Melaleuca alternifolia (Maid. & Bet.) Cheel, and Rosa damascene Mill. were the most active against M. pachydermatis and their activity were high than that of itraconazole at 2 mg/mL. The major constituents of the three oils by GC-MS analysis were linalool (21.83%) and estragole (74.29%) for O. basilicum, a-terpinolene (17.96%) and terpinen-4-01 (45.54%) for M. alternifolia, and a-citronellol (59.98%) and geraniol (27.58%) for R. damascene. Results showed that these selected three oils could be effective toward controlling M. pachydermatis opportunistic infections.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.451-454
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• 2006

Achromobacter xylosoxidans is an aerobic gram-negative bacillus that may cause opportunistic infections in immunocompromized patients and newborns. Neonatal scalp abscess is generally a complication of fetal scalp monitoring and is typically polymicrobial. We present a case of a newborn, delivered by vacuum extraction, who developed a scalp abscess that yielded growth of Achromobacter xylosoxidans.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.8 no.2
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• pp.269-274
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• 2005

Esophageal candidiasis is an opportunistic infection, often reported in patients who have acquired immune deficiency syndrome (AIDS), a neoplastic disease, or undergoing protracted antibiotic therapy. Impaired cell mediated immunity was often considered as the major predisposing factor in patients of esophageal mucosal colonization of Candida spp. However, it is increasingly reported that the occurrence of esophageal candidiasis with no underlying disease or immune suppression. We have experienced a case of esophageal candidiasis in a 15-year-old girl who was immunologically normal and have no underlying disease and whose main symptoms were epigastric and retrosternal pain with dysphagia. This case suggests the possibilities of candidal infections in children without predisposing factors such as immune compromised conditions, so it will be needed to differentiate the esophageal candidiasis among healthy children with symptoms of odynophagia and dysphagia.

• Biomolecules & Therapeutics
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• v.25 no.6
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• pp.569-577
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• 2017

Sepsis is a syndrome characterized by systemic inflammatory responses to a severe infection. Acute hyper-inflammatory reactions in the acute phase of sepsis have been considered as a primary reason for organ dysfunction and mortality, and advances in emergency intervention and improved intensive care management have reduced mortalities in the early phase. However it has been recognized that increased deaths in the late phase still maintain sepsis mortality high worldwide. Patients recovered from early severe illness are unable to control immune system with sepsis-induced immunosuppression such as immunological tolerance, exhaustion and apoptosis, which make them vulnerable to nosocomial and opportunistic infections ultimately leading to threat to life. Based on strategies to reverse immunosuppression, recent developments in sepsis therapy are focused on molecules having immune enhancing activities. These efforts are focused on defining and revising the immunocompromised status associated with long-term mortality.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1625-1628
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• 2006

The (-)-pimara-9 (11), 15-dien-19-oic acid, acanthoic acid was extracted from the roots of Acanthopanax koreanum using bioassay-guided isolation of a MeOH extract. Acanthoic acid was assayed against Streptococcus mutans and Staphylococcus epidermidis causing dental caries and opportunistic pathogen. The minimum inhibitory concentration (MIC) of acanthoic acid against Streptococcus mutans and Staphylococcus epidermidis was 2 and 4 ${\mu}g/mL$, respectively, which was much lower than those of other natural antimicrobial agents such as 8 ${\mu}g/mL$ of tanshinone IIA. Acanthoic acid also significantly inhibited the growth of other cariogenic bacteria such as Streptococcus sobrinus and Streptococcus sanguis, and Streptococcus grodenii in the MIC range of 4${\sim}$32 ${\mu}g/mL$. Our findings suggest that acanthoic acid could be employed as a potential antibacterial agent for preventing dental caries and skin infections.

• Journal of Korean Dental Science
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• v.11 no.2
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• pp.82-85
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• 2018

Leukemia is a hematological malignant disease with various clinical symptoms. Due to the fatal nature of the disease, early detection is important. Oral manifestations include ulcers and gingival enlargement with bleeding. Moreover, myeloid sarcoma or opportunistic infections may also occur. This report introduces a 31-year-old male presenting with generalized gingival enlargement with bleeding and another 81-year-old female with neoplasm on the left retromolar area. Both were diagnosed as acute monocytic leukemia. These cases implicate that gingival enlargement or mucosal lesion in the oral cavity may represent underlying systemic diseases. Related to this, it has to be reminded that making timely diagnosis and referral according to the clinical findings is crucial.

• Journal of Yeungnam Medical Science
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• v.10 no.2
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• pp.518-524
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• 1993

Strongylodiasis is universal in distribution but is most abundant in countries with a tropical climate. Although infestation by Strongyloides stercoralis is usually limited to the intestines, dessemination of this helminth in debilitated host can be lead to death with various clinical disorders, characterized by profound malabsorption, diarrhea, electrolyte imbalance, gram negative or opportunistic fungal sepsis, coma and death. Cell-mediated immunity contributing significantly to the control of helminthic infections, may be suppressed by carcinoma, immunosuppressive chemotherapy and use of corticosteroids. Diagnosis of Strongyloidiasis is achieved by an examination of samples of feces, duodenal aspirates and sputum of patients for Strongyloides stercoralis. Treatment of strongyloidiasis is twofold: correction of the immunosuppressive state by withdrawal of immunosuppressive drug, if possible, and vigorous treatment with thiabendazole. Testing for strongyloidiasis is especially recommanded before treating a patients should be monitored for infection by Strongyloides stercoralis and other opportunistic infection. We are reporting a case patient with Strongyloides stercoralis hyperinfection and pulmonary tuberculosis who had been used corticosteroid for persisting polyarthritis.

• Safety and Health at Work
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• v.6 no.1
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• pp.62-70
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• 2015

Background: Animal skin provides an ideal medium for the propagation of microorganisms and it is used like raw material in the tannery and footware industry. The aim of this study was to evaluate and identify the microbial load in oropharyngeal mucosa of tannery employees. Methods: The health risk was estimated based on the identification of microorganisms found in the oropharyngeal mucosa samples. The study was conducted in a tanners group and a control group. Samples were taken from oropharyngeal mucosa and inoculated on plates with selective medium. In the samples, bacteria were identified by 16S ribosomal DNA analysis and the yeasts through a presumptive method. In addition, the sensitivity of these microorganisms to antibiotics/antifungals was evaluated. Results: The identified bacteria belonged to the families Enterobacteriaceae, Pseudomonadaceae, Neisseriaceae, Alcaligenaceae, Moraxellaceae, and Xanthomonadaceae, of which some species are considered as pathogenic or opportunistic microorganisms; these bacteria were not present in the control group. Forty-two percent of bacteria identified in the tanners group are correlated with respiratory diseases. Yeasts were also identified, including the following species: Candida glabrata, Candida tropicalis, Candida albicans, and Candida krusei. Regarding the sensitivity test of bacteria identified in the tanners group, 90% showed sensitivity to piperacillin/tazobactam, 87% showed sensitivity to ticarcillin/clavulanic acid, 74% showed sensitivity to ampicillin/sulbactam, and 58% showed sensitivity to amoxicillin/clavulanic acid. Conclusion: Several of the bacteria and yeast identified in the oropharyngeal mucosa of tanners have been correlated with infections in humans and have already been reported as airborne microorganisms in this working environment, representing a health risk for workers.