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: 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: 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: 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

BACKGROUND: Accurate detection of extended spectrum beta-lactamase (ESBL) is important because ESBLs producing organisms may appear susceptible to oxyimino-beta-lactams in standard susceptibility tests, but are considered to be clinically resistant to these drugs. Conventional antimicrobial susceptibility test methods do not reliably detect ESBL production. Molecular techniques and NCCLS broth dilution method, which detect ESBL production, may be time consuming, expensive and technically difficult to perform. The purpose of this study is to evaluate the clinical usefulness of NCCLS ESBL phenotypic confirmatory test by disk diffusion method. METHODS: For 96 Escherichia coli and 49 Klebsiella pneumoniae isolates collected between December 2000 to February 2001, double disk synergy test, NCCLS ESBL screening and phenotypic confirmatory test by disk diffusion test were performed. The ESBL producer was defined as organism showed an increase in the zone diameter of > or = 5 mm for either antimicrobial agent such as cefotaxime and ceftazidime tested in combination with clavulanic acid versus its zone when tested alone. RESULTS: The sensitivity of NCCLS ESBL phenotypic confirmatory test were as follows: cefotaxime/clavulanic acid disk; 100% in K. pneumoniae and 83% in E. coli, and ceftazidime/clavulanic acid disk; 94% in K. pneumoniae and 67% in E. coli, respectively. Among the organisms with positive to NCCLS ESBL phenotypic confirmatory test, the detection rate of antimicrobial agents in double disk synergy test were as follows: K. pneumoniae; cefotaxime (84%), aztreonam (74%), and ceftazidime (52%), and E. coli; cefotaxime (44%), ceftazidime (44%), and aztreonam (39%). CONCLUSIONS: The NCCLS ESBL phenotypic confirmatory test by disk diffusion method is easy, rapid, and sensitive method, suitable for routine use in the clinical laboratory.
Anti-Infective Agents ; Aztreonam ; beta-Lactamases* ; Cefotaxime ; Ceftazidime ; Clavulanic Acid ; Diffusion ; Escherichia coli* ; Escherichia* ; Klebsiella pneumoniae* ; Klebsiella* ; Mass Screening ; Pneumonia

Massive intravascular hemolysis secondary to Clostridium perfringens septicemia is rare but often fatal. We report a case of a fatal clostridial hemolytic complication in a 71-year-old woman with probable refractory anemia. The patient was admitted to the emergency room due to a comatose mental state and a high fever. Laboratory analysis showed massive hemolysis. She died from severe anemia two hours after admission. The next day, blood cultures grew gram positive cocci and boxcarshaped gram positive rods, which were identified as coagulase-negative staphylococci and C. perfringens, respectively.
Aged ; Anemia ; Anemia, Refractory ; Clostridium perfringens* ; Clostridium* ; Coma ; Emergency Service, Hospital ; Female ; Fever ; Gram-Positive Cocci ; Gram-Positive Rods ; Hemolysis ; Humans ; Sepsis*

BACKGROUND: This study is designed to provide data on the trend of resistance by year of isolation in the clinical isolates of group B streptococci(GBS) during recent eight years and to elucidate the relationship between serotypes and antimicrobial resistance patterns. METHODS: The minimal inhibitory concentrations (MIC) of seven antimicrobial agents and serotypes for 150 strains of GBS isolated from clinical specimens between 1990 and 1997 were investigated. RESULTS: The resistance rate of 150 clinical isolates of GBS were 20.0% to clindamycin, 16.0% to erythromycin, 4.0% to chloramphenicol, and 95.3% to tetracycline. None was resistant to penicillin, ceftriaxone, or vancomycin. Of the 24 isolates resistant to erythromycin, 20 (83.3%) were resistant to clindamycin. Resistance rates of erythromycin according to serotypes in decreasing order were 69.2% (V), 23.2% (III), and 3.5% (Ib). All serotypes Ia and II were susceptible to erythromycin and clindamycin. CONCLUSIONS: Striking emergence of resistant strains to erythromycin and clindamycin in our clinical isolates of GBS was mainly due to sudden increase of serotype V and III which shows multi-drug resistance phenotype.
Anti-Infective Agents ; Ceftriaxone ; Chloramphenicol ; Clindamycin ; Drug Resistance, Multiple ; Erythromycin ; Penicillins ; Phenotype ; Strikes, Employee ; Tetracycline ; Vancomycin

BACKGROUND: The accurate and rapid identification of enterococci can provide clinician's decision making of antimicrobial therapy because enterococci are usually multiresistant to commonly used antimicrobial agents and antimicrobial resistance patterns are different according to enterococcal species. Accuracy of identification system depends mainly on data base such as positive rate of biochemical reactions, relative frequency of occurrence of biotype, and isolation frequency of microorganisms. The purpose of this study was to analyze the isolation rate and biotype frequency of enterococci isolated from clinical specimens. METHODS: We used a simplified identification system for the identification of the enterococci from clinical specimens during the period of June 1998 to November 1998. Biochemical phenotypes of 500 isolates of enterococci were also analyzed by a simplified identification system consisting of eight conventional biochemical tests. RESULTS: Enterococci were isolated from urine (36.4%), wound (35.0%) and blood (7.2%) in order of decreasing frequency. Among the isolates, 67.8% were E. faecalis, 23.0% E. faecium, 2.2% E. hirae/durans, 2.0% E. casseliflavus, and 1.0% E. hirae. The simplified identification system of enterococci identified 93.6% of all isolates to species level. The system identified 98.5% of E. faecalis but only 89.6% of E. faecium. CONCLUSIONS: Our simplified identification system based on eight biochemical tests offer a simple, reliable and economic method for the identification of clinical isolates of enterococci, but further studies are needed for the improvement of accuracy and identification rate.
Anti-Infective Agents ; Decision Making ; Enterococcus ; Phenotype ; Wounds and Injuries