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1.
Article | WPRIM | ID: wpr-830351

ABSTRACT

Probiotics are used to restore and maintain the healthy intestinal microflora. Although Saccharomyces cerevisiae (SC) is considered as a non-pathogenic yeast, administration of SC as a probiotic is associated with a rare cause of fungemia in immunocompromised patients with central venous catheter insertion. We encountered a case of SC fungemia in a premature infant who presented with respiratory distress syndrome and had undergone central venous catheterization.

3.
Article in English | WPRIM | ID: wpr-714434

ABSTRACT

BACKGROUND: Enterococcus faecium, especially vancomycin-resistant E. faecium (VREfm), is a major concern for patients with hematologic diseases. Exposure to antibiotics including fluoroquinolone, which is used as a routine prophylaxis for patients with hematologic (MH) diseases, has been reported to be a risk factor for infection with vancomycin-resistant eneterocci. We compared the characteristics of E. faecium isolates according to their vancomycin susceptibility and patient group (MH vs non-MH patients). METHODS: A total of 120 E. faecium bacteremic isolates (84 from MH and 36 from non-MH patients) were collected consecutively, and their characteristics (susceptibility, multilocus sequence type [MLST], Tn1546 type, and the presence of virulence genes and plasmids) were determined. RESULTS: Among the vancomycin-susceptible E. faecium (VSEfm) isolates, resistance to ampicillin (97.6% vs 61.1%) and high-level gentamicin (71.4% vs 38.9%) was significantly higher in isolates from MH patients than in those from non-MH patients. Notably, hyl, esp, and pEF1071 were present only in isolates with ampicillin resistance. Among the VREfm isolates, ST230 (33.3%) and ST17 (26.2%) were predominant in MH patients, while ST17 (61.1%) was predominant in non-MH patients. Plasmid pLG1 was more prevalent in E. faecium isolates from MH patients than in those from non-MH patients, regardless of vancomycin resistance. Transposon analysis revealed five types across all VREfm isolates. CONCLUSIONS: The antimicrobial resistance profiles and molecular characteristics of E. faecium isolates differed according to the underlying diseases of patients within the same hospital. We hypothesize that the prophylactic use of fluoroquinolone might have an effect on these differences.


Subject(s)
Ampicillin , Ampicillin Resistance , Anti-Bacterial Agents , Enterococcus faecium , Enterococcus , Gentamicins , Hematologic Diseases , Humans , Multilocus Sequence Typing , Plasmids , Risk Factors , Vancomycin , Vancomycin Resistance , Virulence
4.
Article in English | WPRIM | ID: wpr-717232

ABSTRACT

BACKGROUND: Gastrointestinal (GI) bleeding can result from various conditions, including ulcers, neoplasms and infectious enterocolitis. The aim of this study was to evaluate the utility of the fecal immunochemical transferrin test compared with the fecal Hb test in various clinical settings. METHODS: A total of 1,116 clinical stool specimens submitted for fecal occult blood testing were prospectively examined using both FIT Hb and FIT Tf kits (AlfresaPharma, Japan). To verify the specificity of the two tests, stool specimens from 265 health check-up examinees were also included. RESULTS: A review of medical records revealed that 396 patients had clinical conditions associated with GI bleeding. FIT Hb and FIT Tf results were positive in 156 (39.4%) and 137 (34.6%) cases, respectively, and an additional 194 (49.0%) cases tested positive with either FIT Hb or FIT Tf. The two tests showed a moderate strength of agreement (kappa value; 0.56). Colitis (n=71) was associated with the most GI bleedings, followed by acute gastroenteritis (n=29), GI ulcers (n=27) and GI cancers (n=15). While the first two groups had higher positive rates on FIT Tf, patients in the latter two groups had higher positive rates on FIT Hb. Notably, four of nine specimens from premature babies tested positive only on FIT Tf. The specificity of FIT Hb and FIT Tf was 100% and 99.6%, respectively. CONCLUSION: Concurrent use of FIT Hb and FIT Tf improved the detection rate of occult GI bleeding, especially in patients with infectious GI disease (such as colitis or gastroenteritis) and in premature babies.


Subject(s)
Colitis , Enterocolitis , Gastroenteritis , Hemorrhage , Humans , Medical Records , Occult Blood , Prospective Studies , Sensitivity and Specificity , Transferrin , Ulcer
5.
Article in English | WPRIM | ID: wpr-715636

ABSTRACT

The prevalence of multidrug-resistant gram-negative bacteria has continuously increased over the past few years; bacterial strains producing AmpC β-lactamases and/or extended-spectrum β-lactamases (ESBLs) are of particular concern. We combined high-resolution whole genome sequencing and phenotypic data to elucidate the mechanisms of resistance to cephamycin and β-lactamase in Korean Klebsiella pneumoniae strains, in which no AmpC-encoding genes were detected by PCR. We identified several genes that alone or in combination can potentially explain the resistance phenotype. We showed that different mechanisms could explain the resistance phenotype, emphasizing the limitations of the PCR and the importance of distinguishing closely-related gene variants.


Subject(s)
Drug Resistance, Microbial , Genome , Gram-Negative Bacteria , Klebsiella pneumoniae , Klebsiella , Korea , Phenotype , Polymerase Chain Reaction , Prevalence
6.
Article in Korean | WPRIM | ID: wpr-718744

ABSTRACT

BACKGROUND: The aim of this study was to comparatively evaluate the bactericidal effects of copper, brass (copper 78%, tin 22%), and stainless steel against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VREFM), and multidrug-resistant Pseudomonas aeruginosa (MRPA). METHODS: The isolates (MRSA, VREFM, MRPA) used in this study were mixed wild type 3 strains isolated from patients treated at Uijeongbu St. Mary's Hospital in 2017. These strains showed patterns of multidrug resistance. The lyophilized strains were inoculated into and incubated for 24 hr in tryptic soy broth at 35℃. The initial bacterial inoculum concentration was adjusted to 105 CFU/mL. A 100-mL bacterial suspension was incubated in containers made of brass (copper 78%, tin 22%), copper (above 99% purity), and stainless steel at 35℃. Viable counts of bacteria strains were measured for 9 days. RESULTS: In this study, the bactericidal effects of copper and brass on MRSA, VREFM, and MRPA were verified. The bactericidal effect of stainless steel was much weaker than those of copper and brass. The bactericidal effect was stronger on MRPA than on MRSA or VREFM. CONCLUSION: To prevent cross infection of multidrug resistant bacteria in hospitals, further studies of longer duration are needed for testing of copper materials on objects such as door knobs, faucets, and bed rails.


Subject(s)
Bacteria , Copper , Cross Infection , Drug Resistance, Multiple , Enterococcus faecium , Humans , Methicillin-Resistant Staphylococcus aureus , Pseudomonas aeruginosa , Stainless Steel , Tin
8.
Article in English | WPRIM | ID: wpr-138431

ABSTRACT

BACKGROUND/AIMS: Pneumocystis jirovecii polymerase chain reaction (PCR) can be helpful in diagnosing Pneumocystis pneumonia (PCP); however it has limitations. We evaluated the prevalence of positive P. jirovecii PCR from non-human immunodeficiency virus (HIV) immunocompromised patients and tried to determine the risk of PCP development. METHODS: Between May 2009 and September 2012, P. jirovecii PCR was performed in bronchoscopic specimens from 1,231 adult non-HIV immunocompromised patients suspected of respiratory infection. Only 169 patients (13.7%) who were tested positive for P. jirovecii PCR were enrolled. Retrospective chart review was performed. PCP was defined in patients with positive P. jirovecii PCR who were treated for PCP based on the clinical decision. RESULTS: From 169 P. jirovecii PCR-positive patients, 90 patients were in the PCP group (53.3%) and 79 patients were in the non-PCP group (46.7%). In the PCP group, 38% of patients expired or aggravated after therapy, whereas the majority of patients (84%) in the non-PCP group recovered without treatment for PCP. Independent risk factors for PCP by binary logistic regression analysis were underlying conditions- hematological malignancies, solid tumors or solid organ transplantation, dyspnea, age < 60 years, and albumin < 2.9 g/dL. CONCLUSIONS: This study suggests that not all P. jirovecii PCR-positive patients need to be treated for PCP. Among P. jirovecii PCR-positive patients, those who are less than 60 years old, with hematological malignancies, solid tumors or solid organ transplantation, low albumin, and with symptoms of dyspnea, the possibility of PCP might be higher. Treatment should also be selected to these patients.


Subject(s)
Adult , Dyspnea , Hematologic Neoplasms , Humans , Immunocompromised Host , Logistic Models , Organ Transplantation , Pneumocystis carinii , Pneumocystis , Pneumonia , Pneumonia, Pneumocystis , Polymerase Chain Reaction , Prevalence , Retrospective Studies , Risk Factors , Transplants
9.
Article in English | WPRIM | ID: wpr-138430

ABSTRACT

BACKGROUND/AIMS: Pneumocystis jirovecii polymerase chain reaction (PCR) can be helpful in diagnosing Pneumocystis pneumonia (PCP); however it has limitations. We evaluated the prevalence of positive P. jirovecii PCR from non-human immunodeficiency virus (HIV) immunocompromised patients and tried to determine the risk of PCP development. METHODS: Between May 2009 and September 2012, P. jirovecii PCR was performed in bronchoscopic specimens from 1,231 adult non-HIV immunocompromised patients suspected of respiratory infection. Only 169 patients (13.7%) who were tested positive for P. jirovecii PCR were enrolled. Retrospective chart review was performed. PCP was defined in patients with positive P. jirovecii PCR who were treated for PCP based on the clinical decision. RESULTS: From 169 P. jirovecii PCR-positive patients, 90 patients were in the PCP group (53.3%) and 79 patients were in the non-PCP group (46.7%). In the PCP group, 38% of patients expired or aggravated after therapy, whereas the majority of patients (84%) in the non-PCP group recovered without treatment for PCP. Independent risk factors for PCP by binary logistic regression analysis were underlying conditions- hematological malignancies, solid tumors or solid organ transplantation, dyspnea, age < 60 years, and albumin < 2.9 g/dL. CONCLUSIONS: This study suggests that not all P. jirovecii PCR-positive patients need to be treated for PCP. Among P. jirovecii PCR-positive patients, those who are less than 60 years old, with hematological malignancies, solid tumors or solid organ transplantation, low albumin, and with symptoms of dyspnea, the possibility of PCP might be higher. Treatment should also be selected to these patients.


Subject(s)
Adult , Dyspnea , Hematologic Neoplasms , Humans , Immunocompromised Host , Logistic Models , Organ Transplantation , Pneumocystis carinii , Pneumocystis , Pneumonia , Pneumonia, Pneumocystis , Polymerase Chain Reaction , Prevalence , Retrospective Studies , Risk Factors , Transplants
10.
Infection and Chemotherapy ; : 275-281, 2017.
Article in English | WPRIM | ID: wpr-102696

ABSTRACT

BACKGROUND: Although Escherichia coli is a common cause of bacterial enteritis in Korea, reports on community-acquired E. coli enteritis in Korean children are scarce. This study aimed to determine the clinical characteristics and pathotype distribution of community-acquired E. coli enteritis diagnosed by a multiplex polymerase chain reaction (PCR) assay in Korean children. MATERIALS AND METHODS: The medical records of children aged 18 years or less who were diagnosed with acute gastroenteritis by the attending physician between 2013 and 2016 were retrospectively reviewed. The clinical characteristics of children diagnosed with E. coli enteritis were investigated and compared with those diagnosed with Salmonella enteritis. E. coli and Salmonella infections were diagnosed by a stool PCR assay. RESULTS: Among 279 children, in whom PCR assays for E. coli and Salmonella spp. were performed, Salmonella enteritis and E. coli enteritis were diagnosed in 43 (15.4%) and 39 (14.0%) children, respectively. Among the 39 children with E. coli enteritis, enteropathogenic E. coli (n=21, 53.8%) and enteroaggregative E. coli (n=15, 38.4%) were the most common causative agents. Empirical antibiotics were administered to 33 (84.6%) children. A total of 31 (79.5%) children developed fever, and 25 (80.6%) of them had the fever for 3 days or less, which resolved a median of 1 day (range 0-3 days) after hospitalization. The most frequent gastrointestinal symptom was diarrhea (n=36, 92.3%). Significantly more children with E. coli enteritis were aged 2 years or less as compared with those with Salmonella enteritis (41.0% vs. 21.9%, P = 0.021). Children with Salmonella enteritis more frequently complained of fever (97.7% vs. 79.5%, P = 0.012), abdominal pain (90.7% vs. 64.1%, P = 0.004), and hematochezia (46.5% vs. 10.3%, P < 0.001) than those with E. coli enteritis. Erythrocyte sedimentation rate and C-reactive protein levels were significantly higher in children with Salmonella enteritis than those with E. coli enteritis (P < 0.001). CONCLUSION: Enteropathogenic E. coli was the most frequent pathotype in Korean children with E. coli enteritis that caused mild clinical symptoms. A stool PCR assay for E. coli may be useful for epidemiological purpose and for an early diagnosis of E. coli enteritis.


Subject(s)
Abdominal Pain , Anti-Bacterial Agents , Blood Sedimentation , C-Reactive Protein , Child , Diarrhea , Early Diagnosis , Enteritis , Enteropathogenic Escherichia coli , Escherichia coli , Escherichia , Fever , Gastroenteritis , Gastrointestinal Hemorrhage , Hospitalization , Humans , Korea , Medical Records , Multiplex Polymerase Chain Reaction , Polymerase Chain Reaction , Retrospective Studies , Salmonella , Salmonella Infections
11.
Article in English | WPRIM | ID: wpr-72419

ABSTRACT

BACKGROUND: We evaluated the performance of the BD MAX StaphSR Assay (SR assay; BD, USA) for direct detection of Staphylococcus aureus and methicillin resistance not only in S. aureus but also in coagulase-negative Staphylococci (CNS) from positive blood cultures. METHODS: From 228 blood culture bottles, 103 S. aureus [45 methicillin-resistant S. aureus (MRSA), 55 methicillin-susceptible S. aureus (MSSA), 3 mixed infections (1 MRSA+Enterococcus faecalis, 1 MSSA+MRCNS, 1 MSSA+MSCNS)], and 125 CNS (102 MRCNS, 23 MSCNS) were identified by Vitek 2. For further analysis, we obtained the cycle threshold (Ct) values from the BD MAX system software to determine an appropriate cutoff value. For discrepancy analysis, conventional mecA/mecC PCR and oxacillin minimum inhibitory concentrations (MICs) were determined. RESULTS: Compared to Vitek 2, the SR assay identified all 103 S. aureus isolates correctly but failed to detect methicillin resistance in three MRSA isolates. All 55 MSSA isolates were correctly identified by the SR assay. In the concordant cases, the highest Ct values for nuc, mecA, and mec right-extremity junction (MREJ) were 25.6, 22, and 22.2, respectively. Therefore, we selected Ct values from 0-27 as a range of positivity, and applying this cutoff, the sensitivity/specificity of the SR assay were 100%/100% for detecting S. aureus, and 97.9%/98.1% and 99.0%/95.8% for detecting methicillin resistance in S. aureus and CNS, respectively. CONCLUSIONS: We propose a Ct cutoff value for nuc/mec assay without considering MREJ because mixed cultures of MSSA and MRCNS were very rare (0.4%) in the positive blood cultures.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteremia/diagnosis , Coagulase/metabolism , Humans , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Oxacillin/pharmacology , Reagent Kits, Diagnostic , Staphylococcus/drug effects , Staphylococcus aureus/drug effects
12.
Article in Korean | WPRIM | ID: wpr-151567

ABSTRACT

BACKGROUND: While 7.6% of cultured genital Mycoplasmataceae was identified as Ureaplasma urealyticum, most of them were Ureaplasma parvum (80.3%). This is the first study differentiating between these two species. We investigated the prevalence and antimicrobial resistance of genital Mycoplasmataceae in Korean women. METHODS: A total of 150 specimens submitted to the laboratory for culture of M. hominis and Ureaplasma spp. were included. Detection and antimicrobial susceptibility tests were performed with the Mycoplasma IST2 kit (bioMérieux, France). The identification of Ureaplasma spp. was performed by PCR, and mutations in drug resistance genes were investigated by PCR and sequencing. RESULTS: In total, 66 specimens (44.0%) were positive for genital Mycoplasmatacea: U. parvum, 53 (80.3%); U. urealyticum, 5 (7.6%); M. hominis, 2 (3.0%); mixed infection, 6 (9.1%). Susceptibilities of Ureaplasma spp. to erythromycin, azithromycin, clarithromycin, and doxycycline were 86.0%, 80.7%, 98.2%, and 94.7%, respectively. The susceptibility of Ureaplasma spp. to ofloxacin and ciprofloxacin was 47.4% and 17.5%, respectively. The S83L mutation was found in the ParC subunit of the ofloxacin-resistant (5/7, 71.4%) and the ciprofloxacin-resistant isolates (7/14, 50.0%). One M. hominis isolate showed resistance to erythromycin, azithromycin, and clarithromycin but susceptibility to josamycin, pristinamycin, fluoroquinolones, and tetracyclines. CONCLUSION: The prevalence of genital Mycoplasmataceae in Korean women was 44.0%; most of them were identified as U. parvum. As more than 10% of Ureaplasma spp. showed non-susceptibility to erythromycin and azithromycin (15.5%, 20.7%), a susceptibility test is needed prior to use of these antibiotics. Further study is needed about the clinical features of infections caused by U. urealyticum vs. U. parvum and their associated resistance mechanisms.


Subject(s)
Anti-Bacterial Agents , Azithromycin , Ciprofloxacin , Clarithromycin , Coinfection , Doxycycline , Drug Resistance , Erythromycin , Female , Fluoroquinolones , Humans , Josamycin , Mycoplasma , Mycoplasmataceae , Ofloxacin , Polymerase Chain Reaction , Prevalence , Pristinamycin , Tetracyclines , Ureaplasma , Ureaplasma urealyticum
13.
Article in English | WPRIM | ID: wpr-34960

ABSTRACT

BACKGROUND: We evaluated the reliability and accuracy of the combined use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) bacterial identification and Vitek 2 antimicrobial susceptibility testing (AST) for bacteria from positive blood culture bottles. METHODS: Direct identification and AST were performed in parallel to the standard methods in monomicrobial positive blood culture bottles. In total, 254 isolates grown on aerobic and/or anaerobic bottles were identified with MALDI-TOF Vitek MS (bioMerieux, France), and 1,978 microorganism/antimicrobial agent combinations were assessed. For isolates from anaerobic bottles, an aliquot of the culture broth was centrifuged, washed, and filtered through a nylon mesh. For isolates from aerobic/pediatric bottles, a lysis step using 9.26% ammonium chloride solution and 2% saponin solution was included. RESULTS: The overall correct identification rate was 81.8% (208/254) and that for gram-positive/gram-negative isolates was 73.9%/92.6%, respectively, and it was 81.8%, 87.6%, and 57.9% for isolates from aerobic, anaerobic, and pediatric bottles, respectively. Identification was not possible in 45 cases, and most of these isolates were streptococci (N=14) and coagulase-negative staphylococci (N=11). Misidentification occurred only in one case. Compared with standard methods, direct AST showed 97.9% (1,936/1,978) agreement with very major error of 0.25%, major error of 0.05%, and minor error of 1.8%. CONCLUSIONS: This simple and cost-effective sample preparation method gives reliable results for the direct identification and AST of bacteria. For the identification of streptococci and coagulase-negative staphylococci, the method should be further improved.


Subject(s)
Adult , Ammonium Chloride/chemistry , Anti-Infective Agents/pharmacology , Child , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Humans , Reagent Kits, Diagnostic , Saponins/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
14.
Article in English | WPRIM | ID: wpr-110969

ABSTRACT

BACKGROUND: Periodic monitoring of regional or institutional resistance trends of clinically important anaerobic bacteria is recommended, because the resistance of anaerobic pathogens to antimicrobial drugs and inappropriate therapy are associated with poor clinical outcomes. There has been no multicenter study of clinical anaerobic isolates in Korea. We aimed to determine the antimicrobial resistance patterns of clinically important anaerobes at multiple centers in Korea. METHODS: A total of 268 non-duplicated clinical isolates of anaerobic bacteria were collected from four large medical centers in Korea in 2012. Antimicrobial susceptibility was tested by the agar dilution method according to the CLSI guidelines. The following antimicrobials were tested: piperacillin, piperacillin-tazobactam, cefoxitin, cefotetan, imipenem, meropenem, clindamycin, moxifloxacin, chloramphenicol, metronidazole, and tigecycline. RESULTS: Organisms of the Bacteroides fragilis group were highly susceptible to piperacillin-tazobactam, imipenem, and meropenem, as their resistance rates to these three antimicrobials were lower than 6%. For B. fragilis group isolates and anaerobic gram-positive cocci, the resistance rates to moxifloxacin were 12-25% and 11-13%, respectively. Among B. fragilis group organisms, the resistance rates to tigecycline were 16-17%. Two isolates of Finegoldia magna were non-susceptible to chloramphenicol (minimum inhibitory concentrations of 16-32 mg/L). Resistance patterns were different among the different hospitals. CONCLUSIONS: Piperacillin-tazobactam, cefoxitin, and carbapemems are highly active beta-lactam agents against most of the anaerobes. The resistance rates to moxifloxacin and tigecycline are slightly higher than those in the previous study.


Subject(s)
Agar , Bacteria, Anaerobic , Bacteroides fragilis , Cefotetan , Cefoxitin , Chloramphenicol , Clindamycin , Gram-Positive Cocci , Imipenem , Korea , Metronidazole , Piperacillin
15.
Article in English | WPRIM | ID: wpr-76934

ABSTRACT

BACKGROUND: We investigated the species distribution and amphotericin B (AMB) susceptibility of Korean clinical Aspergillus isolates by using two Etests and the CLSI broth microdilution method. METHODS: A total of 136 Aspergillus isolates obtained from 11 university hospitals were identified by sequencing the internal transcribed spacer (ITS) and beta-tubulin genomic regions. Minimal inhibitory concentrations (MICs) of AMB were determined in Etests using Mueller-Hinton agar (Etest-MH) and RPMI agar (Etest-RPG), and categorical agreement with the CLSI method was assessed by using epidemiological cutoff values. RESULTS: ITS sequencing identified the following six Aspergillus species complexes: Aspergillus fumigatus (42.6% of the isolates), A. niger (23.5%), A. flavus (17.6%), A. terreus (11.0%), A. versicolor (4.4%), and A. ustus (0.7%). Cryptic species identifiable by beta-tubulin sequencing accounted for 25.7% (35/136) of the isolates. Of all 136 isolates, 36 (26.5%) had AMB MICs of > or =2 microg/mL by the CLSI method. The categorical agreement of Etest-RPG with the CLSI method was 98% for the A. fumigatus, A. niger, and A. versicolor complexes, 87% for the A. terreus complex, and 37.5% for the A. flavus complex. That of Etest-MH was < or =75% for the A. niger, A. flavus, A. terreus, and A. versicolor complexes but was higher for the A. fumigatus complex (98.3%). CONCLUSIONS: Aspergillus species other than A. fumigatus constitute about 60% of clinical Aspergillus isolates, and reduced AMB susceptibility is common among clinical isolates of Aspergillus in Korea. Molecular identification and AMB susceptibility testing by Etest-RPG may be useful for characterizing Aspergillus isolates of clinical relevance.


Subject(s)
Amphotericin B/pharmacology , Antifungal Agents/pharmacology , Aspergillus/drug effects , DNA, Fungal/chemistry , Hospitals , Humans , Microbial Sensitivity Tests , Mycoses/diagnosis , Republic of Korea , Sequence Analysis, DNA , Tubulin/genetics
16.
Article in English | WPRIM | ID: wpr-34579

ABSTRACT

BACKGROUND: The usefulness of the CytoDiff flow cytometric system (Beckman Coulter, USA) has been studied in various conditions, but its performance including rapidity in detecting and counting blasts, the most significant abnormal cells in the peripheral blood, has not been well evaluated. The objective of this study was to evaluate the performance of the CytoDiff differential counting method in challenging samples with blasts. METHODS: In total, 815 blood samples were analyzed. Samples flagged as "blasts" or "variant lymphocytes" and showing 0.8) for neutrophils and lymphocytes but poor (r<0.8) for other cells. When the cutoff value of the CytoDiff blast count was set at 1%, the sensitivity was 94.4% (95% CI; 91.2-96.6) and specificity was 91.9% (95% CI; 89.0-94.1). The positive predictive value was 88.4% (95% CI; 84.4-91.5) (304/344 cases) and negative predictive value was 96.2% (95% CI; 93.9-97.7) (453/471 cases). The CytoDiff blast counts correlated well to the manual counts (r=0.9223). CONCLUSIONS: The CytoDiff method is a specific, sensitive, and rapid method for counting blasts. A cutoff value of 1% of at least 1 type of blast is recommended for positive CytoDiff blast counts.


Subject(s)
Adult , Female , Flow Cytometry/instrumentation , Humans , Leukocyte Count , Leukocytes/cytology , Lymphocytes/cytology , Male , Neutrophils/cytology
17.
Article in Korean | WPRIM | ID: wpr-29310

ABSTRACT

BACKGROUND: Most clinical microbiology laboratories in Korea have difficulty in following the recommendations of the clinical procedure handbook for culture of body fluid and wound/abscess specimens. We evaluated the usefulness of MacConkey (MAC) and colistin-nalidixic acid blood agar (CNA) for the isolation of pathogens from these specimens. METHODS: A total of 1,508 clinical specimens [144 peritoneal fluid, 241 body fluids (19 bile, 70 joint fluid, 6 pericardial fluid, 104 pleural fluid, and other fluids in 42 cases) and 1,123 wound/abscess] were inoculated onto basic media [Blood agar plate (BAP), chocolate agar or BAP with streaking of Staphylococcus aureus] and simultaneously inoculated onto MAC and CNA. The pathogens isolated by basic media and by additional use of MAC and/or CNA were compared. RESULTS: With basic media, 885 isolates from 588 specimens were detected, and by additional use of MAC and CNA, an additional 27 isolates from 24 specimens and an additional 128 isolates from 112 specimens were isolated, respectively. Compared to the basic media, by adding MAC, an additional 233.3%, 38.5% and 4.5% of gram-negative bacteria were isolated from peritoneal fluids, body fluid and wound/abscess, respectively, and by adding CNA, an additional 106.7%, 45.0%, and 20.7% of gram-positive bacteria/ yeast were isolated, respectively. The isolates detected by additional use of MAC were mainly Enterobacteriaceae (77.0%), and those detected by CNA were S. aureus (21.1%), Coagulase-negative Staphylococcus spp. (20.3%), Enterococcus spp. (16.4%), Streptococcus spp. (10.2%) and yeasts (16.4%). CONCLUSION: For peritoneal fluid and body fluid specimens, additional use of MAC plus CNA seems necessary for detection of pathogens. For wound/abscess, additional use of CNA will be cost effective.


Subject(s)
Agar , Ascitic Fluid , Bile , Body Fluids , Cacao , Enterobacteriaceae , Enterococcus , Gram-Negative Bacteria , Joints , Korea , Staphylococcus , Streptococcus , Yeasts
18.
Article in English | WPRIM | ID: wpr-57042

ABSTRACT

BACKGROUND: We evaluated the coincidence rate between Vitek MS system (bioMerieux, France) and Vitek 2 in identifying uropathogens directly from urine specimens. METHODS: Urine specimens submitted to our microbiology laboratory between July and September 2013 for Gram staining and bacterial culture were analyzed. Bacterial identification was performed by using the conventional method. Urine specimens showing a single morphotype by Gram staining were processed by culturing and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Of 2,370 urine specimens, 251 showed a single morphotype on Gram staining, and among them, 202 were available for MALDI-TOF MS. RESULTS: In these 202 specimens, colony growth was observed in 189 specimens, and 145 specimens had significant growth of single-colony morphotype in culture. One hundred and ten (75.9%) of them had colony counts of > or =10(5) colony-forming units (CFU)/mL and included 71 enteric gram-negative bacteria (GNB), 5 glucose-non-fermenting GNB, 9 gram-positive cocci (GPC), and 25 yeasts. Furthermore, 70 (98.6%), 3 (60.0%), 4 (44.4%), and 5 (20.0%), respectively, of these were correctly identified by Vitek MS. Thirty-one specimens (21.4%; 11 GNB, 7 GPC, 12 yeasts, and 1 gram-positive bacillus) had colony counts of 10(4)-10(5) CFU/mL. Four specimens (2.8%) yielded colony counts of 10(3)-10(4) CFU/mL. CONCLUSIONS: Vitek MS showed high rate of accuracy for the identification of GNB in urine specimens (> or =10(5) CFU/mL). This could become a rapid and accurate diagnostic method for urinary tract infection caused by GNB. However, for the identification of GPC and yeasts, further studies on appropriate pre-treatment are warranted.


Subject(s)
Gram-Negative Bacteria , Gram-Positive Cocci , Mass Spectrometry , Stem Cells , Urinary Tract Infections , Urinary Tract , Yeasts
19.
Article in English | WPRIM | ID: wpr-81747

ABSTRACT

BACKGROUND: Three chromogenic media using direct inoculation were compared with enriched enterococcosel broth for vancomycin-resistant Enterococcus faecium and/or Enterococcus faecalis (VRE) surveillance. METHODS: A total of 174 rectal swabs were included for VRE surveillance. The specimens were transferred in enterococcosel broth (EB). An aliquot of the broth was inoculated onto Brilliance VRE, chromID VRE, and VRESelect media and incubated for up to 48 h. We examined each media and EB after 24 h and 48 h of incubation. When appropriately colored colonies were observed, identification was confirmed using the VITEK-2 system and/or VITEK MS. Vancomycin susceptibility was confirmed by disk diffusion test. The presence of resistance genes was confirmed using Anyplex VanR Real-time Detection (Seegene, Korea). RESULTS: Of the 174 rectal swab specimens, 73 VRE were isolated. For enterococcosel broth, Brilliance VRE, chromID VRE, and VRESelect, the sensitivity at 24 h was 79.2%, 83.3%, 79.2%, and 79.2%, respectively. The sensitivity at 48 h was 91.7%, 93.1%, 91.4%, and 90.3%, respectively. The specificity at 24 h was 85.3%, 97.1%, 98.0%, and 98.0%, while that at 48 h was 79.4%, 85.3%, 95.2%, and 95.1%, respectively. The specificity of chromogenic media at 24 h and 48 h was significantly higher than that of EB. Furthermore, the specificity at 48 h was significantly higher for chromID VRE and VRESelect than Brilliance VRE, although color distinction was easier with VRESelect. CONCLUSION: Based on our results, use of chromID VRE or VRESelect is more reliable and convenient for screening of VRE. In addition, five vanA-positive Enterococcus gallinarum, Enterococcus avium and Enterococcus durans were isolated, and two of them (one E. avium and one E. durans) were detected only on VRESelect.


Subject(s)
Diffusion , Enterococcus , Enterococcus faecalis , Enterococcus faecium , Mass Screening , Sensitivity and Specificity , Vancomycin
20.
Article in English | WPRIM | ID: wpr-216385

ABSTRACT

We evaluated the performance of a new chromogenic medium for detection of Clostridium difficile, chromID C. difficile agar (CDIF; bioMerieux, France), by comparison with BBL C. difficile Selective Agar (CDSA; Becton Dickinson and Company, USA). After heat pre-treatment (80degrees C, 5 min), 185 diarrheal stool samples were inoculated onto the two media types and incubated anaerobically for 24 hr and 48 hr for CDIF and for 48 hr and 72 hr for CDSA. All typical colonies on each medium were examined by Gram staining, and the gram-positive rods confirmed to contain the tpi gene by PCR were identified as C. difficile. C. difficile was recovered from 36 samples by using a combination of the two media. The sensitivity with CDIF 48 hr was highest (100%) and was significantly higher than that with CDIF 24 hr (58.3%; P<0.001), because samples with a low burden of C. difficile tended to require prolonged incubation up to 48 hr (P<0.001). The specificity of CDIF 24 hr and CDIF 48 hr (99.3% and 90.6%, respectively) was significantly higher than that of CDSA 48 hr and CDSA 72 hr (72.5% and 67.1%, respectively; P<0.001). CDIF was effective for detecting C. difficile in heat-pretreated stool specimens, thus reducing unnecessary testing for toxin production in non-C. difficile isolates and turnaround time.


Subject(s)
Agar/chemistry , Bacterial Proteins/genetics , Bacteriological Techniques/methods , Chromogenic Compounds/chemistry , Clostridioides difficile/genetics , Culture Media/chemistry , DNA, Bacterial/analysis , Diarrhea/microbiology , Feces/microbiology , Humans , Polymerase Chain Reaction , Time Factors
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