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Background@#Staphylococcus aureus is a common colonizer of the nasal vestibule and is found in approximately 20%–30% of healthy adults, while Staphylococcus epidermidis appears to be the most frequent colonizer in all regions of the upper respiratory tract. Esp, aserine protease of S. epidermidis, was reported to inhibit S.aureus colonization. This study was performed to examine the nasal colonization of S. aureus and S. epidermidis and the presence of esp determinants. @*Methods@#Nasal swab specimens from 54 patients were cultured on blood agar plates (BAP) and selective media for S. aureus (S. aureus ID, bioMerieux, France) for the isolation of S.aureus and S. epidermidis. After 48 hours of incubation of with BAP, three or four colonies suspected of being coagulase-negative staphylococci (CNS) were identified by MALDI-TOF MS (Bruker, Germany). Polymerase chain reaction (PCR) for esp was performed on all CNS isolates identified as S. epidermidis. @*Results@#Forty-three S. epidermidis strains were isolated from 18 (33.3%) of the 54 patients.Nine (50.0%) of the 18 patients carried S. aureus, while the other nine did not. Of the 36 S. epidermidis non-carriers, 13 (36.1%) were colonized by S. aureus. All S. epidermidis strains were confirmed by PCR to have esp determinants. @*Conclusion@#S. epidermidis colonization did not affect S. aureus colonization in the nasal cavity. All S. epidermidis strains harbored the esp gene. We could not find any differences in the nasal colonization rates of S. aureus according to the presence of esp-positive S. epidermidis. Further research on the characterization of S. epidermidis in Korea is needed to understand the association between S. epidermidis and S. aureus colonization.
ABSTRACT
Background@#Staphylococcus aureus is a common colonizer of the nasal vestibule and is found in approximately 20%–30% of healthy adults, while Staphylococcus epidermidis appears to be the most frequent colonizer in all regions of the upper respiratory tract. Esp, aserine protease of S. epidermidis, was reported to inhibit S.aureus colonization. This study was performed to examine the nasal colonization of S. aureus and S. epidermidis and the presence of esp determinants. @*Methods@#Nasal swab specimens from 54 patients were cultured on blood agar plates (BAP) and selective media for S. aureus (S. aureus ID, bioMerieux, France) for the isolation of S.aureus and S. epidermidis. After 48 hours of incubation of with BAP, three or four colonies suspected of being coagulase-negative staphylococci (CNS) were identified by MALDI-TOF MS (Bruker, Germany). Polymerase chain reaction (PCR) for esp was performed on all CNS isolates identified as S. epidermidis. @*Results@#Forty-three S. epidermidis strains were isolated from 18 (33.3%) of the 54 patients.Nine (50.0%) of the 18 patients carried S. aureus, while the other nine did not. Of the 36 S. epidermidis non-carriers, 13 (36.1%) were colonized by S. aureus. All S. epidermidis strains were confirmed by PCR to have esp determinants. @*Conclusion@#S. epidermidis colonization did not affect S. aureus colonization in the nasal cavity. All S. epidermidis strains harbored the esp gene. We could not find any differences in the nasal colonization rates of S. aureus according to the presence of esp-positive S. epidermidis. Further research on the characterization of S. epidermidis in Korea is needed to understand the association between S. epidermidis and S. aureus colonization.
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BACKGROUND: Rotavirus is the leading cause of acute viral gastroenteritis, particularly in children, and is transmitted through the fecal-to-oral route by contaminated food or the environment. This study examined the contamination of the inner surfaces of domestic refrigerators with pathogens causing gastroenteritis. METHODS: Swab specimens from shelf surfaces of freezers and refrigerators were collected from 10 domestic refrigerators. Multiplex PCR for bacterial and viral pathogens causing acute gastroenteritis was performed. The VP7 and VP4 genes of rotavirus were amplified and then analyzed by DNA sequencing. RESULTS: Rotavirus was detected in five domestic refrigerators in the same apartment complex. All rotavirus samples showed the G1 genotype and the same DNA sequences. No pathogens causing acute gastroenteritis were identified in the other five domestic refrigerators. CONCLUSIONS: The inner surfaces of domestic refrigerators can be contaminated with pathogens causing acute gastroenteritis, such as rotavirus. Attention should be given to the hygiene of refrigerators. To estimate the contamination or hygienic status for food storage, testing for viral pathogens combined with ordinary bacterial cultures may be necessary.
Subject(s)
Child , Humans , Base Sequence , Food Storage , Foodborne Diseases , Gastroenteritis , Genotype , Hygiene , Multiplex Polymerase Chain Reaction , Rotavirus , Sequence Analysis, DNAABSTRACT
Achromobacter xylosoxidans can cause various types of infections, but its infection in humans is rare. A. xylosoxidans has been reported as a rare etiological agent of infections including primary bacteremia, catheter-related bloodstream infection, endocarditis, otitis, and pneumonia, particularly in immunocompromised hosts. We encountered a case of septic shock caused by A. xylosoxidans in a 52-year-old, immunocompetent woman with no underlying disease, who received extracorporeal shock wave lithotripsy to remove a left upper ureteral stone. She was treated with antibiotics to which the organism was susceptible but died as a result of septic shock.
Subject(s)
Female , Humans , Middle Aged , Achromobacter denitrificans , Achromobacter , Anti-Bacterial Agents , Bacteremia , Endocarditis , Immunocompromised Host , Lithotripsy , Otitis , Pneumonia , Shock , Shock, Septic , UreterABSTRACT
BACKGROUND: Acinetobacter baumannii causes various hospital-acquired infections, its multidrug resistance is rapidly increasing worldwide. Although colistin is used in treatments against multidrug-resistant A. baumannii, resistance to colistin has also been reported recently. Few studies have reported colistin susceptibility testing using MicroScan. In this study, we compared colistin susceptibility tests for resistant A. baumannii by MicroScan (Siemens, USA) and Etest (BioMerieux, France). METHODS: We collected 115 A. baumannii clinical isolates, showing colistin resistance (minimum inhibitory concentration [MIC] > or =4 microg/mL) by MicroScan, from July 2014 to March 2015 at Kangdong Sacred Heart Hospital. Species identification and antimicrobial susceptibility tests were performed using the MicroScan Neg Combo Panel Type 72. Additionally, Etest was also performed for comparison. RESULTS: Of the 115 isolates, Etest revealed that 103 (89.6%) were colistin-susceptible (MIC 4 microg/mL by MicroScan were resistant to colistin according to the Etest. CONCLUSIONS: The MicroScan automated system, using the commercial broth microdilution method, exhibited some discrepancies with the Etest for colistin susceptibility in A. baumannii. Therefore, more practical and reliable susceptibility tests for colistin are required in clinical laboratories using MicroScan.