BACKGROUND: Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are resistant to most β-lactam antibiotics except carbapenems. In recent years, infrequently isolated Enterobacteriaceae that produce carbapenemase pose a serious threat in the selection of appropriate therapeutic antibiotics. The rapid detection method of carbapenemase-producing Enterobacteriaceae (CPE) is necessary to prevent the spread of CPE into healthcare facilities. METHODS: One hundred clinical Enterobacteriaceae isolates (Klebsiella pneumoniae 40, Escherichia coli 40, others 20) showing susceptibility to carbapenems and positivity in the CLSI ESBL phenotypic test from November 2015 to March 2016 and 59 stocked Enterobacteriaceae isolates harboring resistance genes producing carbapenemase (K. pneumoniae 56, Enterobacter cloacae 2, E. coli 1; types of CPE: KPC 36, GES 12, NDM 6, VIM 2, OXA 2, IMP 1) were subjected to the RAPIDEC CARBA NP test (bioMérieux, France) and CPE phenotypic test using the modified Hodge test (MHT) and carbapenemase inhibition test. RESULTS: All of the 100 Enterobacteriaceae isolates with carbapenem susceptibility and ESBL positivity were negative on the RAPIDEC CARBA NP test and CPE phenotypic test. Of 59 stock CPE isolates, 53 and 42 showed positive results to the RAPIDEC CARBA NP test and MHT, respectively. The sensitivity and specificity of the RAPIDEC CARBA NP test for detecting CPE were 89.8% and 100%, respectively. CONCLUSION: The RAPIDEC CARBA NP test is simple and produces a result within 3 hr. In conclusion, the test is a useful screen for detecting CPE because it shows high sensitivity and specificity for CPE detection.
Anti-Bacterial Agents ; Carbapenems ; Delivery of Health Care ; Enterobacter cloacae ; Enterobacteriaceae* ; Escherichia coli ; Methods ; Pneumonia ; Sensitivity and Specificity

Streptococcus bovis bacteremia in humans has been traditionally associated with infective endocarditis, colorectal cancer, and liver cirrhosis. S. bovis strains were previously categorized by biotype, but since the 2000s, they have been reclassified by DNA homology. We report a case of S. gallolyticus subsp. gallolyticus bacteremia, identified by 16S rRNA sequencing, in a patient diagnosed with liver cirrhosis. A 61-yr-old man with a history of liver cirrhosis presented to the hospital with a complaint of fever. Blood culture revealed the presence of gram-positive cocci, and the isolated organism was identified as S. bovis by the MicroScan identification kit (Beckman Coulter, USA), but as Enterococcus saccharolyticus by the Vitek 2 identification kit (bioMérieux, USA). The organism was finally confirmed as S. gallolyticus subsp. gallolyticus by 16S rRNA sequencing.
Bacteremia* ; Colorectal Neoplasms ; DNA ; Endocarditis ; Enterococcus ; Fever ; Gram-Positive Cocci ; Humans ; Liver Cirrhosis* ; Liver* ; Streptococcus bovis ; Streptococcus*

BACKGROUND: The aim of the study was to develop an accurate, convenient, and easy microplate system for the identification of enterococcal species from clinical specimens. METHODS: The microplate identification method was composed of twelve biochemical tests and identification programs. The tests comprised in microplate were initially screened by a two-tube method, NaCl-esculin hydrolysis and pyrrolidonyl-beta-naphthylamide test; arginine dihydrolase, acid production from mannitol, sorbitol, sucrose, arabinose, raffinose, methyl-alpha-D-glucopyranoside, and ribose in the microplate; and pigment production and hemolytic pattern in blood agar plate. The performance of the microplate for identifying enterococci to the species level was evaluated in comparison with conventional reference tests and commercial kits. RESULTS: Among the 111 clinical isolates of Enterococcus species, the microplate system correctly identified 100% to genus level, and 91.0% to species level. All of E. casseliflavus, E. durans, and E. hirae were correctly identified by the microplate. The diagnostic sensitivity and specificity for identification of Enterococcus species were as follows: 100% and 96.7% in E. faecium, 93.5% and 100% in E. faecalis, 100% and 97.2% in E. raffinosus, and 33.3% and 98.1% in both E. avium and E. gallinarum. CONCLUSIONS: It is concluded that the microplate method offers a simple, cost-effective, rapid, and accurate identification system for the identification of most clinical isolates of Enterococcus species.
Agar ; Arabinose ; Arginine ; Enterococcus* ; Hydrolysis ; Mannitol ; Raffinose ; Ribose ; Sensitivity and Specificity ; Sorbitol ; Sucrose

BACKGROUND: The association of Streptococcus bovis biotypes with the type of clinical infection and underlying malignancies and data on antimicrobial susceptibility of S. bovis have rarely been reported in Korea. The aim of this investigation was to characterize the clinical features of patients with S. bovis bacteremia, and to determine the antimicrobial susceptibility of S. bovis strains isolated from blood cultures. METHODS: The clinical data of 67 S. bovis isolates between May 1998 and April 2005 at Wonju Christian Hospital were retrospectively analyzed. The organism was identified by API Strep 32 kit and, for blood isolates, antimicrobial susceptibility testing was performed by the disk diffusion method and penicillin MICs were determined by E test. RESULTS: Of the 67 S. bovis isolates, 18 (27%) were biotype I and 49 (73%) were biotype II. Isolation rates by specimen type were, in decreasing order, wound. 37%; blood, 19%; and urine, 12%. Of the 13 S. bovis bacteremias, 2 were caused by biotype I and 11 were by biotype II; liver diseases (46%) were the most common underlying diseases; none of the 13 patients had gastrointestinal malignancies; one and three isolates were intermediate and resistant to penicillin, respectively; eleven were resistant to erythromycin; two and five were intermediate and resistant to clindamycin, respectively. CONCLUSION: Most of the S. bovis isolates from blood were biotype II. Liver diseases were the most common underlying diseases. S. bovis isolates from blood displayed a high rate of resistance to erythromycin and clindamycin.
Bacteremia* ; Clindamycin ; Diffusion ; Erythromycin ; Gangwon-do ; Humans ; Korea ; Liver Diseases ; Penicillins ; Retrospective Studies ; Streptococcus bovis* ; Streptococcus* ; Wounds and Injuries

BACKGROUND: Increased resistance rates to macrolide-lincosamide-streptogramin B (MLSB) antibiotics among clinical isolates of staphylococci are considered as a consequence of an expanded use of these antibiotics in the treatment of Gram-positive infections. The proportion of MLSB resistance phenotypes of staphylococci is quite different by geographical variations and study periods. The aim of the present study was to determine the distribution of MLSB resistance phenotypes among clinical isolates of staphylococci in a university hospital. METHODS: The MLSB resistance phenotypes of clinical isolates of staphylococci were investigated by the double-disk diffusion test using erythromycin and clindamycin disks. RESULTS: Of 7,916 isolates, 55.7% exhibited a constitutive resistance phenotype (cMLSB) whereas 8.1% expressed an inducible resistance phenotype (iMLSB). Among 3,419 coagulase-negative staphylococci (CNS), 32.6% and 10.0% exhibited cMLSB and iMLSB resistance phenotypes, respectively. Of 4,497 Staphylococcus aureus isolates, 73.1% and 6.8% were cMLSB and iMLSB resistance phenotypes, respectively. cMLSB was detected among 90.2% of methicillin-resistant S. aureus (MRSA), 46.5% of methicillin-resistant CNS (MRCNS), 3.2% of methicillin-susceptible CNS (MSCNS), and 2.2% of methicillin-susceptible S. aureus (MSSA). iMLSB was detected among 16.5% of MSSA, 11.5% of MRCNS, 6.7% of MSCNS, and 4.4% of MRSA. CONCLUSION: MLSB resistance was more prevalent among S. aureus isolates than CNS strains. Although cMLSB was the most frequently detected resistance phenotype among the total staphylococcal isolates, methicillin-susceptible strains exhibited somewhat higher iMLSB resistance rates compared with methicillin-resistant strains.
Anti-Bacterial Agents ; Clindamycin ; Diffusion ; Erythromycin ; Methicillin Resistance ; Phenotype ; Staphylococcus aureus

BACKGROUND: Accurate detection of extended spectrum beta-lactamase (ESBL) is important because ESBLproducing organisms may appear susceptible to oxyimino- beta-lactams in standard susceptibility tests, but are considered to be clinically resistant to these drugs. And continued monitoring of isolation trend of ESBL-producing organisms is essential for the guideline settlement of antibiotic usage and infection control program. METHODS: Disk diffusion test using the Clinical and Laboratory Standards Institute's ESBL phenotypic confirmatory test were performed on 5,511 clinical isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus mirabilis during the recent six years (April 2001-March 2007). The ESBL producer was defined as an organism showing an increase in the zone diameter of > or =5 mm for either cefotaxime or ceftazidime with clavulanic acid versus that without clavulanic acid (CTC confirmatory test, CZC confirmatory test, respectively). RESULTS: The ESBL-positive rates were 34.8% in K. pneumoniae, 9.3% in K. oxytoca, 8.4% in E. coli, and 6.5% in P. mirabilis. Among the ESBL-positive organisms, the detection rates of ESBL CTC and CZC confirmatory tests were as follows: 91.3% vs 68.7% in K. pneumoniae, 96.3% vs 44.4% in K. oxytoca, 94.8% vs 45.4% in E. coli, and 100% vs 20% in P. mirabilis. ESBL-producing K. pneumoniae had shown a continuously increasing trend from 24.3% in 2001 to 46.4% in 2006. CONCLUSION: Both of the ESBL confirmatory tests should be simultaneously tested for the accurate detection of ESBL-producing K. pneumoniae, K. oxytoca, E. coli, and P. mirabilis. In addition, an active infection control approach is needed for ESBL-producing K. pneumoniae.
beta-Lactamases* ; beta-Lactams ; Cefotaxime ; Ceftazidime ; Clavulanic Acid ; Diffusion ; Escherichia coli* ; Escherichia* ; Infection Control ; Klebsiella oxytoca ; Klebsiella pneumoniae ; Klebsiella* ; Mirabilis ; Pneumonia ; Proteus mirabilis* ; Proteus*

BACKGROUND: Erythromycin is currently recommended as an alternative antibiotic for treatment of streptococcal infections in patients allergic to penicillins. Less than 5% of the group A streptococci are known as resistant to erythromycin but the resistance pattern differs among time and region. The purpose of this study was to determine the antimicrobial susceptibility of beta-emolytic streptococcal strains isolated during 1999 in Wonju. METHODS: A total of 107 beta-emolytic streptococci were isolates from the Wonju Christian Hospital during 1999. The susceptibility to penicillin, erythromycin, tetracycline, vancomycin, ceftriaxone, chloramphenicol, and clindamycin was tested with agar dilution method. RESULTS: No beta-emolytic streptococci strain was resistant to penicillin, ceftriaxone and vancomycin. Among beta-emolytic streptococci strains, 20-1%, 18-0% and 14-7% were resistant to tetracycline, erythromycin and clindamycin, respectively. CONCLUSIONS: It appears prudent that active surveillance of the beta-emolytic streptococci for antibiotic resistance be implemented since there are no currently effective vaccines or other methods for controlling the spread of infections due to these virulent organisms.
Agar ; Ceftriaxone ; Chloramphenicol ; Clindamycin ; Drug Resistance, Microbial ; Erythromycin ; Gangwon-do ; Humans ; Penicillins ; Streptococcal Infections ; Tetracycline ; Vaccines ; Vancomycin

BACKGROUND: Erythromycin is currently recommended as an alternative antibiotic for treatment of streptococcal infections in patients allergic to penicillins. Less than 5% of the group A streptococci are known as resistant to erythromycin but the resistance pattern differs among time and region. The purpose of this study was to determine the antimicrobial susceptibility of beta-emolytic streptococcal strains isolated during 1999 in Wonju. METHODS: A total of 107 beta-emolytic streptococci were isolates from the Wonju Christian Hospital during 1999. The susceptibility to penicillin, erythromycin, tetracycline, vancomycin, ceftriaxone, chloramphenicol, and clindamycin was tested with agar dilution method. RESULTS: No beta-emolytic streptococci strain was resistant to penicillin, ceftriaxone and vancomycin. Among beta-emolytic streptococci strains, 20-1%, 18-0% and 14-7% were resistant to tetracycline, erythromycin and clindamycin, respectively. CONCLUSIONS: It appears prudent that active surveillance of the beta-emolytic streptococci for antibiotic resistance be implemented since there are no currently effective vaccines or other methods for controlling the spread of infections due to these virulent organisms.
Agar ; Ceftriaxone ; Chloramphenicol ; Clindamycin ; Drug Resistance, Microbial ; Erythromycin ; Gangwon-do ; Humans ; Penicillins ; Streptococcal Infections ; Tetracycline ; Vaccines ; Vancomycin

BACKGROUND: Viridans group streptococci (VGS) are being increasingly reported as pathogens causing septicemia in neutropenic and other immunocompromised patients since 1980s. In the past, VGS were nearly uniformly susceptible to beta-lactam antimicrobial agents, aminoglycosides, tetracyclines, and macrolides. Several recent published studies, however, indicate that antimicrobial resistance may be emerging as a problem with VGS. The purpose of this study was to determine the antimicrobial susceptibility of VGS strains isolated from blood cultures in recent period. METHODS: A total of 45 consecutive strains of VGS isolated from blood cultures between May 2001 and March 2002 at Wonju Christian Hospital were tested for antimicrobial susceptibility. Identification of VGS were performed by API Strep 32(bioMerieux sa, Marcy-l'Etoile, France) commercial kit. Antimicrobial susceptibility tests were done by NCCLS recommended disk diffusion method and penicillin MICs were determined by E test. RESULTS: Among the 45 VGS strains, frequently isolated organisms were Streptococcus mitis (31.1%), Streptococcus oralis (17.8%), Streptococcus constellatus (11.1%), and Streptococcus anginosus (8.9%). Overall intermediate-and resistant rates to antimicrobial agents of VGS were as follows: penicillin; 26.7% and 8.9%, erythromycin; 4.4% and 28.9%, clindamycin 2.2% and 22.2%, and ceftriaxone; 4.4% and 6.7%, respectively. Resistant rates of Streptococcus mitis and Streptococcus oralis were as follows: penicillin; 50% vs 50%, erythromycin 43% vs 37%, clindamycin 21% vs 37%, and ceftriaxone 7% vs 25%, respectively. CONCLUSIONS: These results indicate the species-related variability of susceptibility among VGS isolated from blood in recent period. In addition to S. mitis, S. oralis also displayed high rates of resistance to penicillin, macrolides, and ceftriaxone. The difference in susceptibilities between species of VGS indicates the importance of accurate identification and the need for continuing monitoring of antimicrobial resistance.
Aminoglycosides ; Anti-Infective Agents ; Ceftriaxone ; Clindamycin ; Diffusion ; Erythromycin ; Gangwon-do ; Immunocompromised Host ; Macrolides ; Penicillin Resistance ; Penicillins ; Sepsis ; Streptococcus anginosus ; Streptococcus constellatus ; Streptococcus mitis ; Streptococcus oralis ; Tetracyclines ; Viridans Streptococci*

BACKGROUND: Bone turnover markers (BTMs) are widely used tool for monitoring the response to osteoporosis therapy, and the normal adult reference range is the baseline value for the treatment of osteoporosis with anti-resorptive agents. This study was aimed to establish age- and sex-specific reference ranges of serum osteocalcin and serum type I collagen C-telopeptide (S-CTX) in adults based on menstrual stage. METHODS: Serum osteocalcin, S-CTX and bone mineral density (BMD) were measured in 291 adults (men: 162, women: 129), and follicle stimulating hormone (FSH) in women. Seven women whose serum FSH levels were >30 IU/mL were categorized as perimenopausal despite their regular menses. RESULTS: Among females with normal BMD, there were no difference in serum osteocalcin and S-CTX levels between premenopausal and postmenopausal women. Females with osteopenia in pre- and postmenopausal stage showed higher serum osteocalcin and S-CTX levels than females with normal BMD. For subjects with normal BMD, reference ranges of serum osteocalcin and S-CTX were 6.4~21.6 ng/mL and 0.08~0.85 ng/mL for 30~59-year-old females. For males with normal BMD, reference ranges of serum osteocalcin were 10.1~24.3 ng/mL for 30~39 years old and 7.7~22.4 ng/mL for 40~59 years old, and reference range of CTX was 0.13~1.27 ng/mL for 30~59 years old. CONCLUSIONS: This study will provide a redefinition of the criteria required in order to establish the normal reference ranges for BTMs. Moreover, we believe that our data will come in handy when used as normal reference ranges of BTMs in premenopausal women.
Adult ; Bone Density ; Bone Diseases, Metabolic ; Collagen Type I ; Female ; Follicle Stimulating Hormone ; Humans ; Male ; Osteocalcin ; Osteoporosis ; Peptides ; Reference Values