• Journal of Life Science
• /
• v.17 no.4 s.84
• /
• pp.581-586
• /
• 2007

Staphylococcus epidermidis is a coagulase-negative, gram-positive bacterium that normally inhabits the human skin. S. epidermidis is also known to be an opportunistic pathogen in infections of various indwelling medical devices. This report describes purification and characterization of the urease of S. epidermidis urease, which may act as a virulence factor. The urease from S. epidermidis was purified 1,127 fold by using DEAE-Sepharose, Phenyl-Sepharose, Mono-Q and Superdex HR200 column chromatography. The specific activity of the purified enzyme was 993.8 U/mg. Michaelis constant($K_m$) of the enzyme was estimated to be 8.5 mM urea by using Lineweaver-Burke double reciprocal plot. The native molecular weight of the urease was shown to be 255 kD by using Superose 6HR gel filtration chromatography and the purified enzyme contained 2.2 nickel ions per catalytic unit. The overall stoichiometry of the enzyme subunits appears to be $(\alpha\beta\gamma)_3$, which is consistent with the enzymes from other bacteria sources.

• Journal of Veterinary Clinics
• /
• v.32 no.2
• /
• pp.212-214
• /
• 2015

Encephalitoozoon cuniculi is an obligate intracellular microsporidian parasite commonly found in rabbits, causing encephalitozoonosis. This organism can also infect a wide range of hosts including humans, which is known to cause opportunistic infections in immunocompromised individuals. In this case, four rabbits presented with head tilt and nystagmus were diagnosed for E. cuniculi infection using ELISA. The rabbits were treated with fenbendazole for 4 weeks and therapeutic success was evaluated by assessing the neurological symptoms. Three out of 4 rabbits showed improved health condition 3 to 5 days after treatment, but one rabbit showed persistent anorexia and head tilt after treatment and then died after 10 days. This report is the first to investigate the therapeutic response of fenbendazole for rabbit encephalitozoonosis in Korea, and suggests that pet rabbits may serve as potential E. cuniculi reservoirs for both pet animals and humans.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.4
• /
• pp.579-585
• /
• 2013

Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus, SEZ) is an important pathogen associated with opportunistic infections of a wide range of species, including pigs and humans. The absence of a suitable vaccine makes it difficult to control SEZ infection. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been previously identified as an immunogenic protein using immunoproteomic techniques. In the present study, we confirmed that the sequence of GAPDH was highly conserved with other Streptococcus spp. The purified recombinant GAPDH could elicit a significant humoral antibody response in mice and confer significant protection against challenge with a lethal dose of SEZ. GAPDH could adhere to the Hep-2 cells, confirmed by flow cytometry, and inhibit adherence of SEZ to Hep-2 cells in an adherence inhibition assay. In addition, real-time PCR demonstrated that GAPDH was induced in vivo following infection of mice with SEZ. These suggest that GAPDH could play an important role in the pathogenesis of SEZ infection and could be a target for vaccination against SEZ.

• Tuberculosis and Respiratory Diseases
• /
• v.64 no.5
• /
• pp.387-391
• /
• 2008

Bronchopulmonary infections caused by trichomonads have been reported principally in patients with pre-existing pulmonary diseases, such as bronchial carcinoma, lung abscess, or bronchiectasis. Pulmonary trichomoniasis is most often caused by Trichomonas tenax, which is usually regarded as a harmless commensal organism of the human mouth. However, pulmonary infection may rarely be caused by other trichomonas species, including Trichomonas vaginalis from the genitourinary tract and Trichomonas hominis from the intestines. Because of the rarity of trichomonas pulmonary infection, and because of its close association with underlying lung and systemic disease, pulmonary trichomoniasis is considered an opportunistic infection. We recently treated a case of pulmonary trichomoniasis occurring in a young, healthy male without obvious underlying pulmonary or systemic illness. To our knowledge, there has been only one reported case of pulmonary trichomoniasis in Korea, and there have been only two reported cases of pulmonary trichomoniasis occurring in normal lung worldwide.

• Mycobiology
• /
• v.47 no.3
• /
• pp.335-339
• /
• 2019

Endophytic fungi have the ability to live inside the host plant tissues without causing neither symptoms of diseases/or harm. Opportunistic infections are accountable for majority of the outbreaks, thereby putting a burden on the health system. To investigate and characterize the bioactive compounds for the control of bacteria of clinical importance, extracts from endophytic fungi were isolated from indigenous South African medicinal plants. Extracts from endophytic fungi were isolated from 133 fungal strains and screened against Gram positive and negative bacteria namely Bacillus cereus, Escherichia coli, Enterococcus faecium, and E. gallinarum using disk diffusion. Furthermore, gas chromatography-mass spectrometry was performed to identify the bioactive compounds. Sixteen out of one hundred and thirty-three (12%) fungi extracts exhibited antibacterial properties against some of the selected bacteria. E. coli was found to be the most susceptible in contrast to E. faecium and E. gallinarum which were the most resistant. The isolate MHE 68, identified as Alternaria sp. displayed the greater spectrum of antibacterial activities by controlling selected clinical bacteria strains including resistant E. faecium and E. gallinarum. The chemical analysis of the extract from MHE 68 indicated that linoleic acid (9,12-octadecadienoic acid (Z,Z)) and cyclodecasiloxane could be accountable for the antibacterial activity. This is the first study conducted on the secondary metabolites produced by endophytic fungal strains isolated from the Pelargonium sidoides DC. possessing antibacterial properties.

• Korean Journal of Microbiology
• /
• v.55 no.1
• /
• pp.64-66
• /
• 2019

Cutibacterium acnes is a member of normal flora of human skin, conjunctiva, intestinal tract, the external auditory canal as well as oral cavity. It has been identified as an opportunistic pathogen related to acne vulagris, endocarditis infections, sarcoidosis, brain abscess, periodontitis, and osteomyelitis of the humerus. C. acnes KCOM 1315 (= ChDC KB81) was isolated from a human jaw osteomyelitis lesion. Here, we present the complete genome sequence of C. acnes KCOM 1315.

• Biomedical Science Letters
• /
• v.24 no.4
• /
• pp.430-434
• /
• 2018

Candida glabrata is the second most prevalent causative agent for candidiasis following C. albicans. The opportunistic yeast, C. glabrata, is able to cause the critical bloodstream infections in hospitalized patients. Conventional identification methods for yeasts are often time consuming and labor intensive. Therefore, recent studies on sequence-based identification have been conducted. Recently, sequencing the D1/D2 domain of the large subunit ribosomal RNA gene and the internal transcribed spacers (ITS) 1 and ITS2 regions of the ribosomal DNA has proven useful for DNA-based identification of most species of fungi. In the present study, therefore, fungal ITS and D1/D2 domain regions were targeted and analyzed by DNA sequencing for the accurate identification of C. glabrata clinical isolates. A total of 102 C. glabrata clinical isolates from various clinical samples including bloodstream, catheterized urine, bile and other body fluids were used in the study. The results of the DNA sequence analysis showed that the mean standard deviation of species identity percent score between ITS and D1/D2 domain regions was $97.8%{\pm}2.9$ and $99.7%{\pm}0.46$, respectively. These results revealed that the D1/D2 domain region might be a better target for identifying C. glabrata clinical isolates based on DNA sequences than the ITS1 and ITS2 regions. However, in order to evaluate the usefulness of D1/D2 domain region for species identification of all Candida species, other Candida species such as C. albicans, C. tropicalis, C. dubliniensis, and C. krusei should be verified in further studies additionally.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.5
• /
• pp.696-703
• /
• 2019

Cronobacter sakazakii is an opportunistic pathogen causing serious infections in neonates. In this study, a bacteriophage ${\Phi}CS01$, which infects C. sakazakii, was isolated from swine feces and its morphology, growth parameters, and genomic analysis were investigated. Transmission electron microscopy revealed that ${\Phi}CS01$ has a spherical head and is 65.74 nm in diameter with a 98.75 nm contracted tail, suggesting that it belongs to the family Myoviridae. The major viral proteins are approximately 71 kDa and 64 kDa in size. The latent period of ${\Phi}CS01$ was shown to be 60 min, and the burst size was 90.7 pfu (plaque-forming units)/infected cell. Bacteriophage ${\Phi}CS01$ was stable at $4-60^{\circ}C$ for 1 h and lost infectivity after 1 h of heating at $70^{\circ}C$. Infectivity remained unaffected at pH 4-9 for 2 h, while the bacteriophage was inactivated at pH <3 or >10. The double-stranded ${\Phi}CS01$ DNA genome consists of 48,195 base pairs, with 75 predicted open reading frames. Phylogenetic analysis is closely related to that of the previously reported C. sakazakii phage ESP2949-1. The newly isolated ${\Phi}CS01$ shows infectivity in the host bacterium C. sakazakii, indicating that it may be a promising alternative to antibacterial agents for the removal of C. sakazakii from powdered infant formulas.

• Journal of Veterinary Clinics
• /
• v.37 no.6
• /
• pp.342-344
• /
• 2020

Bacterial osteomyelitis-or bacterial infection of the bone-is common in reptiles. Unfortunately, its treatment is challenging despite advances in diagnostic and medical technologies. Herein, we present the case of a sexually mature female bearded dragon (Pogona vitticeps) with left forelimb elbow joint stiffness. We diagnosed the reptile with a eft elbow joint traumatic structural abnormality based on gross examination and evaluation of radiographs. Treatment with clindamycin and cephalexin for bacterial infection failed and the reptile died. Necropsy revealed the causative bacteria as Morganella morganii. Treatment of osteomyelitis is typically focused against Staphylococcus aureus as it the most common cause of traumatic bone infection. However, M. morganii, the causative bacterium in this case, has a natural resistance to clindamycin and cephalexin. Recently, these bacteria have begun to appear in clinical reports, more commonly as the causative organisms of bone infections. M. morganii should be considered as a potential cause of infection. Furthermore, antibiotic treatment in such cases should be based on bacterial culture and susceptibility tests.

• Korean Journal of Clinical Laboratory Science
• /
• v.54 no.2
• /
• pp.119-124
• /
• 2022

Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are typical opportunistic pathogens. Moreover, these bacteria are known to possess multidrug-resistant (MDR) properties. This study investigates the antimicrobial activity of six fermented products, which have varying efficacies against P. aeruginosa, E. coli, and S. aureus. To identify novel candidate genes, differential expression analysis was performed using an annealing control primer. In the disk diffusion method, Fig vinegar (FV) and Diospyros kaki Thunb vinegar (DTV) showed the greatest increase in inhibition compared to other fermented products, whereas fermented Korean traditional nature herb (FKTNH) had no antibacterial effect. This study identified down-regulation of Escherichia coli O157:H7 ompW gene for outer membrane protein W, whereas gene for synthetic construct Lao1 gene for L-amino acid oxidase were up-regulated in E. coli treated with 5% FV. Consuming fermented vinegar helps prevent bacterial infections. Especially, FV and DTV are potentially useful alternative natural products for multidrug resistance. Furthermore, both are expected to be used as effective natural antimicrobial agents, such as disinfectants.