• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.87-94
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• 2003

The lytic activity of the set of swine and chicken phages which were derived from lysogenic Staphylococcus hyicus strains of swine and chicken origin was compared by means of S. hyicus isolated from swine, chicken and cattle. Of the 80 strains each from swine and chicken, 71 (88.8%) of strains from swine and all the strains of chicken origin were found to be lysogenic. Swine phages showed wider range of lytic activity to the examined strains than that of chicken phages. Using chicken phages at $100{\times}routine$ test dilution (RTD), 25.0%, 85.6% and 50.0% of swine, chicken and bovine strains were lysed, respectively. However, when the set of swine phages was used at $100{\times}RTD$, higher frequency of the typable strains was found in strains of swine and chicken origin (73.8% and 90.2%). Phage F12 and L16 from chicken set were found to be highly active with chicken and bovine strains. On the contrary, all the swine strains were completely resistant to lysis by the two phages at $100{\times}RTD$. Thirteen (12.5%) of 104 S. aureus strains, 1 (1.8%) of 55 S. simudance strains, 31 (58.5%) of 53 S. chromo genes strains, and none of 31 strains of other coagulase-negative Staphylococcus species isolated from bovine mastitis were typable with the set of swine phages.

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

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.9
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• pp.1322-1328
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• 2012

Antibiotic resistance patterns of bacterial isolates from both quarter teat-tip swabs and their quarter milk samples were evaluated in smallholder dairy farms in northern Thailand with excessive use of antibiotics (HIGH) compared with normal use (NORM). Results from teat-tip swab samples showed that the percentage of Bacillus spp. resistance to overall antibiotics was significantly lower in the NORM group than that of the HIGH group, whereas, the resistance percentage of coagulase-negative staphylococci in the NORM group was higher than that of the HIGH one. The overall mastitis-causing bacteria isolated from milk samples were environmental streptococci (13.8%), coagulase-negative staphylococci (9.9%), Staphylococcus aureus (5.4%), and Corynebacterium bovis (4.5%). Both staphylococci and streptococci had significantly higher percentages of resistance to cloxacillin and oxacillin in the HIGH group when compared to the NORM one. An occurrence of vancomycin-resistant bacteria was also observed in the HIGH group. In conclusion, the smallholder dairy farms with excessive use of antibiotics had a higher probability of antibiotic-resistant pattern than the farms with normal use.

• Journal of Life Science
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• v.19 no.11
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• pp.1499-1505
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• 2009

This study was carried out between August and September 2007 to determine the causative agents and epidemiologic features of rabbit dermatitis in Korea. Rabbits were shipped to the laboratory in the College of Veterinary Medicine from 10 rabbit farms. A total of 520 hair, blood, and skin specimens collected from skin lesions of 40 rabbits with suspected dermatopathy were examined mycologically, bacteriologically, and parasitologically. The positive rates of dermatophytosis, bacterial skin dermatitis, and ectoparasite dermatitis were 95, 92.5, and 7.5%, respectively. The etiologic agents of dermatophytosis were identified as Trichophyton mentagrophyte (95%), non-dermatophytic filamentous fungi such as Aspergillus s(5%), and Cryptococcus humilocus (2.5%). With respect to bacteria-related skin dermatitis, Staphylococcus coagulase negative was the most common etiological agent. Staphylococcus aureus was the second most frequent causative agent. Most of the pathogenic isolates were resistant to tetracycline, and aminoglycosides such as amikacin and gentamicin were the most effective drugs against the pathologic bacteria isolated. Ectoparasites were rarely detected in this study. Only Psoroptes cuniculis was detected in 3 (7.5%) out of the 40 tested rabbits. The role of ectoparasites as a causative agent of dermatitis in rabbits in this study was minimal. Our results provide important information related to rabbit dermatitis treatments and researches.

• YAKHAK HOEJI
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• v.50 no.3
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• pp.204-207
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• 2006

A total of 398 strains of Staphylococcus aureus (99), coagulase-negative staphylococci (CNS) (99), enterococci (100), Streptococcus pyogenes (18) and Streptococcus agalatiae (82) were in Korean tertiary hospital from Dec. 2004 to Mar, 2005. When minimal inhibitory concentrations (MIC), phenotypes and genotypes were determined, 70% of S. aureus, 65.7% of CNS, 78% of enterococci and 37.8% of S. agalatiae were resistant to erythromycin and 95.7% of erythromycin-resistant (EMR) S. aureus, 92.3% of EMR CNS and all of EMR enterococci and S. agalatiae had erm of the methylase gene or msr(A) of the efflux gene.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.115-125
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• 2000

Three major hospitals with over 500 beds located in and near Seoul were surveyed for airbone microorganisms from February 1, 1998 to February 18, 1998. The purpose of the study was to identify and quantify microbiological organisms circulating in the air of three different areas in the hospitals. For the study, a RCS air sampler was utilized equipped with two different collection media, the agar strip GK-A for bacteria and the agar strip HS for fungi. The areas investigated were the intensive care unit (ICU) in the Department of internal medicine, the Newborns room in the Department of Obstetrics, and the microbiology laboratory. The results were as follows; 1. The average numbers of general microbiological particles collected on the agar strip GK-A media were $205CFU/m^3$, $232CFU/m^3$, and $128CFU/m^3$ in each hospitals. The highest concentration of $387CFU/m^3$ was found in the ICU of A hospital at 15:00 during the day. Further analysis of the collected bioaerosols by gram staining, revealed that there were gram positive cocci (89.5%), gram positive bacilli (7.2%), gram negative bacilli (2.8%), and fungi (0.5%), in descending order of frequency. 2. Ten different genes were identified from the agar strip GK-A. The most frequently identified organisms were: the Coagulase negative staphylococcus (55.0%), Micrococcus (21.4%), Enterococcus species(10.4%), and Bacillus species (7.2%). A series of antibiotics susceptibility test were conducted against the aforementioned four(4) organisms. Ninety percent of coagulase negative stapylococcus were sensitive to Penicillins. Pathogenic microbes isolated include: Staphylococcus aureus, Acinetobacter species, Klebsiella pneumonia, Klebsiella oxytoca, and Pseudomonas aeroginosa. 3 Although 56.8% of the microorganisms grown on the strip HS media for fungi could not be identified, some of them were successfully identified. The most frequently found fungi were Aspergillus (35.3%), Yeast or Molds (6.2%), and Penicillium (0.7%). Based on the results obtained from the study, it was concluded that some areas in the hospitals had abnormally high bioaerosol concentrations which could be attributed to human activity. Therefore, it is recommended that periodic assessments of indoor bioaerosols aiming to identify the possible sources should be conducted in order to maintain clean indoor environment in the hospitals.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.231-241
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• 1998

To assess biological indoor air quality in hospital, concentrations of viable airborne microbes were determined at intensive care unit(ICU), patient room (PR), outpatient waiting room(OPWR) in hospitals of large(1000 beds), middle(500 beds), small(100 beds) hospitals, respectively. Gram positive bacteria, gram negative bacteria, fungi were sampled using suctional sampling method by RCS sampler (Reuter centrifugal air sampler) and RCS GK-A agar plate. In gram positive bacteria groups, CNS(Coagulase Negative Staphylococcus), Micrococcus, Lactobacillus, S. aureus, Enterococcus, St. viridans identified. In gram negative bacteria groups, A. baumannii, Kl. peumoniae and E. coli were identified, and Penicillium was identified in fugi groups. Results of the study were as follows. 1. The highest concentrations of airborne microbes was $971CFU/m^3$ at 5:00 PM in small hospital patient room, and average concentrations of airborne microbes in large, middle and small hospitals were $282CFU/m^3$, $289CFU/m^3$ and $625CFU/m^3$, respectively. Average concentrations of airborne microbes in office(control) was $90CFU/m^3$. Thus, the small hospital showed the worst condition. 2. Representatives of 8 different genera were identified in 150 samples. The most frequently isolated organisms were Staphylococcus (73.0%), Micrococcus (20.7%) and Lactobacillus (4.7%), respectively. Pathogenic microbes isolated were A. baumannii, E. coli, Enterococcus, Kl. peumoniae, S. aureus, St. viridans and Penicillium as fungi. In office, no pathogenic microbes were identified. Average concentrations of airborne pathogenic microbes in large, middle and small hospital were $5CFU/m^3$ (2%), $11CFU/m^3$ (4%) and $12CFU/m^3$ (2%), respectively. Thus, condition in a large hospital was better than those in a middle and a small hospital.

• YAKHAK HOEJI
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• v.48 no.6
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• pp.364-368
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• 2004

The prevalence of resistance to a range of macrolides was determined for clinical isolates of common respiratory pathogens using NCCLS testing methods and interpretative criter ia.71.4% of Streptococcus pneumoniae, 62.3% of Staphylococcus aureus, 50.8% of coagulase-negative staphylococci and 4.4% of Strpetococcus pyogenes were erythromycin resistant. Also, the rates of resistance to other macrolides and clindamycin in these clinical isolates were as high as to eryth -romycin. Almost all of the macrolide-resistant isolates were positive for erm of the methylase gene, or mef of the efflux gene.

• Child Health Nursing Research
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• v.22 no.4
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• pp.379-389
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• 2016

Purpose: A longitudinal study was conducted to explore flora colonization and oral glucose high-risk newborns during the first 7 days after birth. Methods: Oral secretions of hospitalized newborns were obtained for microbial cultures and glucose test at days 1-7 after birth. Results: Among the total 112 newborns, 40% were girls and 73% were premature. Mean gestational age was $34.4{\pm}3.2$ weeks and weight was $2,266{\pm}697.5$ grams. The most common flora included Streptococcus (28.2%), Methicillin-resistant Staphylococcus aureus (MRSA, 10.9%), Staphylococcus (6.0%) and Coagulase-Negative Staphylococcus (CNS, 4.0%). The average oral glucose level was $29.2{\pm}23.0mg/dL{\sim}58.2{\pm}39.5mg/dL$. Newborns with higher oral glucose than serum (crude odds ratio [ORc] =1.75; 95% confidence interval [CI] =1.03-2.97), phototherapy (ORc=3.30; 95% CI=2.29-4.76) and prone position (ORc= 2.04; 95% CI=1.13-3.69) were more likely to be colonized. Having oral tubes (ORc=0.42; 95% CI=0.29-0.59), parental nutrition (ORc=0.21; 95% CI=0.13-0.32) and antibiotics (ORc=0.51; 95% CI=0.36-0.73) had protective effects. For oral glucose statistical significances existed on time effect among newborns with Streptococcus (F=9.78, p=.024), MRSA (F=7.60, p=.037) or CNS (F=11.15, p=.019) and interaction between time and colonization among newborns with all of four flora (F=2.73, p=.029) or colonization with only Staphylococcus (F=2.91, p=.034). Conclusion: High-risk newborns develop flora colonization at an early period of life. Their clinical features were associated with types and time of oral flora colonization. They need close monitoring and multifaceted intervention to improve oral environment and infection control.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.93-101
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• 2012

We analyzed mupirocin resistance rates among staphylococcal isolates collected from a Korean hospital in 2003 (100 isolates), 2005 (195 isolates), 2006 (151 isolates), and 2009 (112 isolates). In Staphylococcus aureus, rates of high-level mupirocin resistance (MIC, minimal inhibitory concentration ${\geq}512{\mu}g/ml$) decreased and did not appear since 2005. In contrast, low-level mupirocin resistance (MIC $8-256{\mu}g/ml$) was not detected in 2003 and 2005 but its rates later increased to 6.9% in 2009. Total resistance rates of coagulase-negative staphylococci (CNS) were significantly higher than those of S. aureus. The rates of high-level resistance of CNS increased from 16.0% in 2003 to 31.5% in 2009. The rate of low-level resistance of CNS was 8.0% in 2003 and around 11% later. In all high-level resistant isolates, the ileS-2 gene was detected. All low-level resistant isolates contained the known V588F mutation in ileS gene. Previously unknown mutations such as V458G in S. aureus and D172A, Y490H and I750V in CNS were identified additionally. One S. aureus isolate with high-level resistance was resistant to oxacillin and several topical antibiotics commonly used for the treatment of skin infection. Ten S. aureus isolates with low-level resistance were also resistant to all of these antibiotics except fusidic acid. CNS isolates with high-level (61 isolates) and low-level resistance (27 isolates) exhibited significantly higher resistance rates to these antibiotics than mupirocin-susceptible CNS isolates (167 isolates). In conclusion, prevention of the emergence of mupirocin resistance is necessary for the effective treatment of skin infection by staphylococci.