A Case of Streptococcus gallolyticus subsp. gallolyticus Bacteremia in Liver Cirrhosis

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.

Evaluation of Diagnostic Performance of RAPIDEC CARBA NP Test for Carbapenemase-Producing Enterobacteriaceae / 대한임상미생물학회지

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.

Frequency and Clinical Characteristics of Urinary Tract Infections Caused by Staphylococcus saprophyticus / 대한임상미생물학회지

BACKGROUND: Staphylococcus saprophyticus is the second most common cause of urinary tract infections (UTIs) in young women. As little is known about the incidence of UTIs caused by this organism in Korea, we examined its frequency and clinical characteristics. METHODS: We analyzed the frequency of S. saprophyticus among organisms isolated from urine specimens in Wonju Christian Hospital from July 1996 to June 2008 and reviewed clinical characteristics retrospectively. RESULTS: Of 24,277 strains isolated from urine specimens during the past 12 years, 21 (0.09%) were S. saprophyticus. Outpatients were more common in the S. saprophyticus group than in all patients group (12 of 21, 57% vs 5,098 of 24,277, 21%). The incidence of S. saprophyticus in women was the highest in the group of 15 to 34 years of age. Monthly distributions of isolates were almost constant in all patient groups, while 16 of 21 (76%) cases of the S. saprophyticus group occurred in summer and fall (June to November). CONCLUSION: The fequencies of S. saprophyticus among organisms isolated from urine specimens in all patient groups and women were 0.09% and 0.17%, respectively, and are much lower than those in other countries. However, we need further studies to examine the prevalence of S. saprophyticus UTIs in other regions of this country.

Age and Sex Specific Reference Ranges of Serum Type I Collagen C-telopeptide and Osteocalcin Based on Menstrual Stage / 임상검사와정도관리

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.

Distributions of Macrolide-Lincosamide-Streptogramin B Resistance Phenotypes in Clinical Isolates of Staphylococi / 대한임상미생물학회지

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.

In Vitro Antimicrobial Activities of NanoSilver-coated Gauze against Clinical Isolates / 대한임상미생물학회지

BACKGROUND: It is well-known that silver ions and silver compounds are broad-spectrum antimicrobial agents effective against gram-positive and gram-negative bacteria, and yeasts. Thus, silver ions, as an antibacterial agent, have been used in the components of materials used in medical devices or coatings. Recently, advances in nanotechnology have enabled manufacturers to develop silver particles of a nanometer size with a safer and more effective antimicrobial activity. So, we evaluate the antimicrobial activity of nanoSilver-coated gauze against clinical isolates. METHODS: Three kinds of nanoSilver-coated gauzes (100A, 800A, and 1,500A) were tested for antimicrobial activity by the disk diffusion method. The organisms tested included clinical isolates of nonfermentative gram-negative bacilli (143 isolates), aerobic gramnegative bacteria (188), aerobic gram-positive bacteria (397), anaerobic bacteria (46), and yeasts (161), and three reference ATCC strains. RESULTS: The susceptible rates to NanoSilver of nonfermentative gram-negative bacilli (NFB), aerobic gramnegative bacteria and aerobic gram-positive bacteria were 87%, 87% and 78%, respectively. Antimicrobial activity of NanoSilver against imipenem-resistant NFB, extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae, and methicillin-resistant Staphylcoccus aureus (MRSA) was similar to that against imipenem-sensitive NFB, ESBL non-producing Enterobacteriaceae, and methicillin-susceptible S. aureus. CONCLUSION: NanoSilver-coated gauze exhibits broad spectrum antimicrobial activities to a large number of gram-negative and gram-positive bacteria including imipenem-resistant NFB, ESBL producing Enterobacteriaceae, and MRSA.

Isolation Frequency of Extended Spectrum beta-Lactamase Producing Escherichia coli, Klebsiella species, and Proteus mirabilis / 대한임상미생물학회지

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.

Underlying Diseases Associated with Streptococcus bovis Bacteremia and Antimicrobial Susceptibility of the Organism / 대한임상미생물학회지

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.

A Case of Escherichia coli O157 and Campylobacter species Gastroenteritis / 대한임상미생물학회지

Verotoxin-producing Escherichia coli O157 is a primary cause of severe and bloody diarrhea. Campylobacter spp. are one of the commonly reported bacterial cause of gastrointestinal infections throughout the world. Only a few cases involving both E. coli O157 and Campylobacter species have been reported. The authors simultaneously isolated verotoxin-producing E. coli O157 and Campylobacter species from the stool of a 3 year-old male with bloody diarrhea, fever and abdominal pain.

Identification of Enterococcus Species Using a Microplate / 임상검사와정도관리

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.

Antimicrobial Susceptibilities of Viridans Streptococci Isolated from Blood Cultures during Recent Period / 임상검사와정도관리

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.

Antimicrobial Susceptibility of beta-emolytic Streptococci Isolated during the Period of 1999 / 대한임상병리학회지

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.

Antimicrobial Susceptibility of beta-emolytic Streptococci Isolated during the Period of 1999 / 대한임상병리학회지

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.