BACKGROUND: The erythromycin-resistance rate and phenotype distribution of Streptococcus propenes are quite different by geographical variation and study period. The aim of the present study was to determine the evolution of resistance to erythromycin and the frequency of erythromycin resistance phenotype of S. pyogenes isolated from Wonju Christian Hospital. METHODS: The minimal inhibitory concentrations (MICs) of erythromycin and clindamycin for 94 S. pyogenes isolated from clinical specimens between 1990 to 1998 were investigated. Double disk test of erythromycin (78microgram) and clindamycin (25microgram) were performed for 15 isolates of erythromycin resistant S. pyogenes to evaluate the erythromycin resistance phenotype. RESULTS: The resistance rates of 94 isolates of S. pyogenes were 16%(15/94) to erythromycin and 4%(4/94) to clindamycin. The frequency of erythromycin resistance phenotype in decreasing order were M phenotype (47%), inducible resistance phenotype (40%), and constitutive resistance phenotype (13%). Erythromycin-resistant S. pyogenes did not exist until 1993, but was isolated since 1994, and ranged from 14.0% to 24.0% during the period of 1994-1998. CONCLUSIONS: Our finding documents the emergence of high resistance rates to erythromycin in S. pyogenes at Wonju area since 1994. The M phenotype (47%) and inducible resistance phenotype (40%) account for the majority of erythromycin-resistant S. pyogenes.
Clindamycin ; Erythromycin* ; Gangwon-do ; Phenotype* ; Streptococcus pyogenes* ; Streptococcus*

BACKGROUND: To access the accuracy and clinical usefulness of microplate identification (ID) system for the identification of Enterobacteriaceae, we compared microplate ID system with API 20E(bioMerieux, Etoile, France). METHODS: Ninety-two cultures of Enterobacteriaceae and one isolate of Aeromonas species were simultaneously identified by microplate ID system and the API 20E. Twenty biochemical tests used in microplate ID system were lactose, sucrose, and H2S in Kligler's iron agar media; indole, sucrose, raffinose, arabinose, trehalose, adonitol, dulcitol, sorbitol, cellibiose, methy-red, phenylalanine deaminase, ornithine decarboxylase, lysine decarboxylase, arginine dihydrolase, urease, and citrate in microplate; and oxidase test. The identification was obtained by considering percent likelihood(% ID), modal frequency and ID score method. RESULTS: Among the 92 cultures of Enterobacteriaceae and one isolate of Aeromonas species, agreement rate of identification according to the % ID between microplate ID system and API 20E were 90.3% to the species level and 97.8% to the genus level. CONCLUSIONS: For the identification of clinical Enterobacteriaceae isolates, the microplate ID system compares favorably with API 20E in identification accuracy and have the advantage of costsaving and easy to use.
Aeromonas ; Agar ; Arabinose ; Arginine ; Citric Acid ; Enterobacteriaceae* ; Galactitol ; Iron ; Lactose ; Lysine ; Ornithine Decarboxylase ; Oxidoreductases ; Phenylalanine ; Raffinose ; Ribitol ; Sorbitol ; Sucrose ; Trehalose ; Urease

BACKGROUND: Recent data suggest that the colonization rate of group B streptococci(GBS) in pregnant women and the incidence of neonatal infections by GBS is increasing trend in Korea, but the antimicrobial susceptibilities and serotypes in pregnant women have not been reported in Korea. So, we studied to define the antimicrobial susceptibility patterns and frequency of serotypes of GBS in pregnant women. METHODS: The susceptibility and serotyping of 60 GBS isolates from 27 pregnant women and four isolates from their two neonates were tested by an agar dilution method and agglutination test, respectively. The typing sera used in this study were Ia, Ib, II, III, IV, and V. RESULTS: Minimal inhibitory concentration range of 60 GBS from pregnant women were penicillin G 0.015-0.12 microgram/ml, vancomycin 0.5-2 microgram/ml, clindamycin 0.015-4.0 microgram/ml, chloramphenicol 2-4 microgram/ml, erythromycin 0.015-2 microgram/ml, tetracycline 0.5-256 microgram/ml, cephalothin 0.12-0.25 microgram/ml, ceftriaxone 0.03-0.12 microgram/ml, respectively. The resistance rate of GBS were 6.7% to clindamycin, 0% to erythromycin, and 98.3% to tetracycline. Most of GBS serotypes from pregnant women in decreasing order were Ib(48.3%), Ia(24.1%), III(20.7%). CONCLUSION: All GBS strains isolated from pregnant women are highly susceptible to commonly used antimicrobial agents with the exception of tetracycline. The low prevalence of severe neonatal GBS infections in Korea is not due to the absence of serotype III, but probably due to a low genital carriage rate of GBS by pregnant women.
Agar ; Agglutination Tests ; Anti-Infective Agents ; Ceftriaxone ; Cephalothin ; Chloramphenicol ; Clindamycin ; Colon ; Erythromycin ; Female ; Humans ; Incidence ; Infant, Newborn ; Korea ; Penicillin G ; Pregnant Women* ; Prevalence ; Serotyping ; Tetracycline ; Vancomycin

BACKGROUND: Pigment production and acidification of ribose are most frequently used biochemical tests for the differentiation of three enterococcal species carrying vanC genes such as Enterococcus gallinarum, Enterococcus casseliflavus, and Enterococcus flavescens. However, pigment production may occasionally be negative in E. casseliflavus, and some of E. casseliflavus may be negative or delayed reaction with ribose fermentation test. So, we performed this study to find out biochemical tests capable of distinguishing the strains possessing vanC genotypes. METHOD: A total of 17 enterococci composed of 14 clinical isolates with motility or pigment positive strains and three ATCC strains(E. gallinarum ATCC 49573, E. casseliflavus ATCC 25788, and E. flavescens ATCC 49997) Were tested by multiplex PCR of the vanC genes(vanC-1, vanC-2 and vanC-3)and various biochemical tests. RESULTS: Among the 17 isolates including three ATCC control strains, four were genotyped as VanC-1, 11 were VanC-2, one were vanC-2/3, and any of vanC genes were not detected in one clinical isolate, respectively, Among the enterococci with vanC genotype, acid production from alphaD-cyclodextrin and hippurate hydrolysis were positive only in VanC-1 gneotype(E. gallinarum), acid production from glycerol and methyl-alpha-D-mannopyranoside were positive only in vanC-2 genotype(E. casseliflavus), and acid production from rhamnose and pigment production were negative only in VanC-1 genotype. Acid production from alphaD-cyclodextrin was negative only in vanC-2 genotype. The positive rate of ribose fermentation of VanC-1, VanC-2, and VanC-2/3(E. flavescens) genotype were 100%, 82%, and 0%, respectively. CONCLUSION: Acid production from rhamnose, alphaD-cyclodextrin, betaD-cyclodextrin, glycerol and methly-alphaD-mannopyranoside, pigment production, and hippurate hydrolysis test were useful biochemical tests for differentitating E. gallinarum form E. casseliflavus. The production of acid from alphaD-cyclodextrin, glycerol, methyl-alpha-D-mannopyranoside and were suitable biochemical tests for differentiating E. casseliflavus from E. flavescens.
Enterococcus ; Fermentation ; Genotype ; Glycerol ; Hydrolysis ; Multiplex Polymerase Chain Reaction ; Phenotype* ; Rhamnose ; Ribose

BACKGROUND: Candidemia has increased with an increasing number of people in the high risk group and so has become more important. This study was conducted to investigate the isolation rate of Candida species from candidemia patients and the change in rate of antifungal resistance. METHODS: At a single tertiary care hospital, 1,120 blood cultures positive for Candida species from 1997 to 2016 were investigated according to date of culture, gender, age, and hospital department. RESULTS: During the investigation period, the number of candidemia patients increased from 14 in 1997 to 84 in 2016. The most common organism identified during the two decades was Candida albicans (40.8%), followed by Candida parapsilosis (24.1%), Candida tropicalis (13.2%), and Candida glabrata (12.8%). C. glabrata was relatively common in females (45.5%) compared to males. The age group 40-89 years was more frequently infected than other age groups, and the most frequent isolates according to age group were C. albicans in neonate (66.7%), C. parapsilosis in 1-9-year-olds (41.7%), and C. glabrata in those aged ≥60 years (range; 13.3%–20.0%). According to the visited departments, C. albicans, C. glabrata, and Candida haemulonii were more common in medical departments, while C. parapsilosis was more common in surgical departments. In the antifungal susceptibility test, a rising trend of azole resistance among C. albicans and C. glabrata was observed in recent years. CONCLUSION: In this study, it was confirmed that the isolation rate of Candida species in blood is different by age, gender, and hospital department, and the distribution of isolated Candida species changed over time. The resistance patterns of antifungal agents are also changing, and continuous monitoring and proper selection of antifungal agents are necessary.
Antifungal Agents ; Candida albicans ; Candida glabrata ; Candida tropicalis ; Candida* ; Candidemia* ; Danazol ; Drug Resistance, Fungal* ; Female ; Hospital Departments ; Humans ; Infant, Newborn ; Male ; Prevalence* ; Tertiary Healthcare*

BACKGROUND: This study is designed to provide data on the trend of serotypes of group B streptococci (GBS) isolated from clinical specimens during recent eight years and to elucidate the relationship between biochemical reactions and serotypes of GBS. METHODS: Serotyping, pigment production test, CAMP test, hippurate hydrolysis, and hemolysis test were performed for 150 GBS isolates from clinical specimens during March 1990 to February 1998. The typing sera used were Ia, Ib, II, III, IV, and V. Pigment production was detected by new Granada tube medium. The CAMP test and hippurate hydrolysis were performed by standard technique. Hemolytic patterns of GBS were determined on sheep blood agar and human blood agar plate. RESULTS: GBS were frequently isolated from cervix, urine, wound (pus), and blood. Striking increase of GBS isolates were notified from 1996 to 1997 period. Identification rates of GBS serotypes were Ib (38.0%), III (37.3%), Ia (9.3%), V (8.7%), nontypable strains (4.0%), and II (2.7%) in decreasing order. The proportion of serotype III increased markedly from 1996. Serotype V was not isolated until 1996, and ranked third in 1997. Seven (4.7%) isolates were nonhemolytic, and six of seven isolates revealed serotype III. Two (1.3%) isolates that were negative in both CAMP test and hippurate hydrolysis were serotype II. CONCLUSIONS: Clinical microbiology laboratories relying on beta hemolysis or pigment production for initial detection of GBS may underestimate the isolation rate of GBS and the proportion of serotype III which hardly makes hemolysis. It is therefore recommended that laboratories providing cultures for the GBS of genitalia specimens supplement other detection methods such as CAMP test or immunologic methods.
Agar ; Cervix Uteri ; Female ; Genitalia ; Hemolysis ; Humans ; Hydrolysis ; Serotyping ; Sheep ; Strikes, Employee ; Wounds and Injuries

No abstract available.
Bacteremia* ; Corynebacterium* ; Korea

The aim of this study was to investigate antimicrobial susceptibilities and macrolide resistance mechanisms of beta-hemolytic viridans group streptococci (VGS) in a tertiary Korean hospital. Minimum inhibitory concentrations (MICs) of seven antimicrobials were determined for 103 beta-hemolytic VGS isolated from various specimens. The macrolide resistance mechanisms of erythromycin-resistant isolates were studied by the double disk test and polymerase chain reaction (PCR). The overall resistance rates of beta-hemolytic VGS were found to be 47.5% to tetracycline, 3.9% to chloramphenicol, 9.7% to erythromycin, and 6.8% to clindamycin, whereas all isolates were susceptible to penicillin G, ceftriaxone, and vancomycin. Among ten erythromycin-resistant isolates, six isolates expressed a constitutive MLSB (cMLSB) phenotype, and each of the two isolates expressed the M phenotype, and the inducible MLSB (iMLSB) phenotype. The resistance rates to erythromycin and clindamycin of beta-hemolytic VGS seemed to be lower than those of non-beta-hemolytic VGS in our hospital, although cMLSB phenotype carrying erm(B) was dominant in beta-hemolytic VGS.
Ceftriaxone/pharmacology ; Chloramphenicol/pharmacology ; Clindamycin/pharmacology ; Cross Infection/*genetics ; *Drug Resistance, Bacterial ; Erythromycin/pharmacology ; Humans ; Immunoenzyme Techniques ; Korea ; Macrolides/*pharmacology ; Penicillin G/pharmacology ; Phenotype ; Polymerase Chain Reaction ; Tetracycline/pharmacology ; Vancomycin/pharmacology ; Viridans Streptococci/*genetics/*metabolism

BACKGROUND: The selection of identification (ID) system of Enterobacteriaceae depends mainly on accuracy of identification system, cost of operation and convenience of testing. Commercial ID kits are easy to use but too expensive. Therefore, we designed a computerized ID system based on 10 tubes which were composed of 14 conventional biochemical tests to identify the Enterobacteriaceae and Vibrionaceae. The purpose of this present study was to assess the clinical usefulness of 10 tube system as an identification system for Enterobacteriaceae in clinical microbiology laboratories. METHODS: During the period of January 1998, 189 Enterobacteriaceae and 2 Aeromonas spp. consecutively isolated from clinical specimens were simultaneously identified by 10 tube system and the API rapid ID 32 E. Fourteen conventional biochemical tests used in 10 tube system were lactose, sucrose, and H2S in Kligler's iron agar media; motility, indole, and ornithine decarboxylase in motility-indole-ornithine decarboxylase agar media; citrate, urease, lysine decarboxylase, phenylalanine deaminase, arginine dihydrolase, arabinose, trehalose, and adonitol. Identification program used in 10 tube system were % ID method and ID score method. RESULTS: Among the 191 isolates, agreement rate of identification between 10 tube system and API rapid ID 32 E were 96.0% to the species level and 99.4% to the genus level. And identification accuracy of 10 tube system was 90.6% to the species level and 93.2% to the genus level. CONCLUSIONS: 10 tube system has been shown to be an accurate, cost-effective alternative to the use of commercial kit systems for identification of Enterobacteriaceae.
Aeromonas ; Agar ; Arabinose ; Arginine ; Citric Acid ; Enterobacteriaceae* ; Iron ; Lactose ; Lysine ; Ornithine Decarboxylase ; Phenylalanine ; Ribitol ; Sucrose ; Trehalose ; Urease ; Vibrionaceae

No abstract available.
Aerococcus* ; Gene Expression* ; Korea* ; Vancomycin Resistance* ; Vancomycin*