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ABSTRACT: We report the first case of pulmonary disease caused by a strain of Mycobacterium avium complex of presumed veterinary origin in an elderly patient. All serial isolates were identified by multi-locus sequence analysis based on rpoB, hsp65, and 16S rRNA fragments. Disease persisted despite macrolide-based combination antibiotic therapy.
Journal of clinical microbiology 04/2013; · 4.16 Impact Factor
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ABSTRACT: Background: Although extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli has emerged as a significant pathogen, there is little information regarding treatment outcomes in community-onset bacteremia due to ESBL E. coli. The purpose of this study was to evaluate treatment outcomes of community-onset bacteremia caused by ESBL-producing E. coli and the factors associated with mortality. Methods: A retrospective cohort study was performed, including 92 adult patients with community-onset bacteremia caused by ESBL-producing E. coli. Results: The 30-day mortality rate was 10.9% (10/92). Independent risk factors for mortality were underlying liver disease and severity of illness (e.g., high Pitt bacteremia score, the presence of severe sepsis or septic shock; p < 0.05). Mortality in patients receiving inappropriate initial antimicrobial therapy was not significantly higher than mortality in those receiving appropriate empirical antimicrobial therapy (10.9 vs 10.7%; p = 0.975), if antimicrobial therapy was adjusted appropriately according to susceptibility results. Carbapenems, piperacillin/tazobactam, fluoroquinolones, and amikacin were the most effective antibiotics for community-onset bacteremia caused by ESBL-producing E. coli, although susceptibility profiles confirmed that alternatives to carbapenems are limited. Of 68 isolates in which the ESBLs and their molecular relationships were studied, all isolates produced ESBLs from the CTX-M family (CTX-M-14, 30 isolates; CTX-M-15, 22; and other CTX-M, 16). Conclusions: In patients with community-onset bacteremia caused by ESBL-producing E. coli, severe sepsis and underlying liver disease were significantly associated with mortality, and a delay in appropriate antimicrobial therapy was not associated with a higher mortality if therapy was adjusted appropriately according to the susceptibility results.
Scandinavian Journal of Infectious Diseases 03/2013; · 1.72 Impact Factor
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ABSTRACT: Lindnera (Pichia) fabianii (Candida fabianii teleomorph) is a yeast species that is an uncommon cause of invasive human infections. This report describes the first human case of a catheter-related L. fabianii bloodstream infection in a neutropenic patient. The CLSI guideline does not offer the antifungal breakpoints in this neutropenic case and emperical chemotherapy was considered. Sharing our experience, we will discuss the choice of an effective antifungal agent in this uncommon clinical situation.
Journal of Medical Microbiology 03/2013; · 2.50 Impact Factor
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ABSTRACT: Geosmithia argillacea, an anamorph of Talaromyces eburneus, is a thermophilic filamentous fungus that has a phenotype similar to that of the Penicillium species, except for the creamy-white colonies and cylindrical conidia. Recently, a new genus called Rasamsonia has been proposed, which is to accommodate the Talaromyces and Geosmithia species. Here, we report the first Korean case of G. argillacea isolated from a patient with a fungal ball. The patient was a 44-yr-old Korean man with a history of pulmonary tuberculosis and aspergilloma. The newly developed fungal ball in his lung was removed and cultured to identify the fungus. The fungal colonies were white and slow-growing, and the filaments resembled those of Penicillium. Molecular identification was carried out by sequencing the internal transcribed spacer (ITS) region of the 28S rDNA and the β-tubulin genes. A comparative sequence analysis using the GenBank (http://blast.ncbi.nlm.nih.gov/) database was performed with the basic local alignment search tool (BLAST) algorithm. The results revealed a 97-100% similarity with the G. argillacea ITS sequence. This case should increase awareness among physicians about the pathogenic potential of G. argillacea in humans and help them accurately identify this fungus, because it can be easily confused with Penicillium and Paecilomyces species owing to their similar phenotypic and microscopic characteristics. A molecular approach should be employed to enable accurate identification of G. argillacea.
Annals of laboratory medicine. 03/2013; 33(2):136-140.
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The Korean Journal of Internal Medicine 03/2013; 28(2):258-60.
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ABSTRACT: BACKGROUND: There are no available studies on the duration and risk factors of vancomycin-resistant enterococci (VRE) carriage after hospital discharge. In this study we investigated the duration of colonization with VRE and the risk factors for prolonged carriage in the outpatient clinic after discharge from the hospital. METHODS: The study took place from January 2008 to September 2009. Patients were included if they were identified as persistent VRE carriers by follow-up rectal swab or stool cultures in the outpatient setting, after discharge from the hospital without clearance of VRE. The probability of culture positivity and clearance was analyzed from the discharge date. Cox regression was performed to determine the risk factors for prolonged carriage. VRE clearance was defined as VRE-negative rectal (or stool) cultures on at least three consecutive occasions a minimum of 1 week apart. RESULTS: One hundred twenty-seven patients were included in this study. Follow-up cultures were conducted for a median of 8.86 weeks (range 1-90 weeks) after hospital discharge. The median duration of culture positivity of VRE was 5.57 weeks (range 0-50.14 weeks). Ninety-six out of 127 patients (75.6%) showed the first negative culture result at a median time of 4.86 weeks (range 0-66 weeks) after discharge. Among these patients, 15 were lost to follow-up after the first negative culture and eight were lost after the second negative culture. Sixty-eight patients (53.5%) were confirmed to have clearance of VRE during follow-up in the outpatient clinic. The median time to clearance after discharge was 8.86 weeks (range 2-90 weeks). In the cleared cases, the median time to the first negative VRE culture result was 4.71 weeks (range 0-66 weeks). Ninety percent of patients showed the first negative culture result at 25 weeks and VRE clearance at 30 weeks after discharge. Surgery or antibiotic use during admission (p=0.048 and p=0.001, respectively), dialysis (p=0.046), and discharge to a nursing home or other health care institution (p=0.025) were independently associated with prolonged colonization with VRE. CONCLUSIONS: The median duration of VRE colonization was 5.57 weeks after hospital discharge. In the cases with clearance during follow-up, the median time to clearance after discharge was 8.86 weeks. Risk factors for prolonged carriage were surgery, antibiotic use during admission, dialysis, and discharge to a nursing home or other health care institution. Therefore, patients with these risk factors should be managed more carefully to prevent transmission of VRE in the outpatient clinic.
International journal of infectious diseases: IJID: official publication of the International Society for Infectious Diseases 11/2012; · 2.17 Impact Factor
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ABSTRACT: A single sputum culture positive for nontuberculous mycobacteria (NTM) could be an early sign of NTM lung disease. We found that 14% of patients with a single sputum culture positive for pathogenic NTM were diagnosed with NTM lung disease during the median follow-up period of 16 months.
Diagnostic microbiology and infectious disease 11/2012; · 2.45 Impact Factor
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ABSTRACT: Since microbial gene sequencing was utilized for etiologic diagnosis of culture-negative endocarditis, cases of Bartonella endocarditis have been reported in various countries. Herein we report the first case of Bartonella quintana endocarditis, which was confirmed for the first time in Korea by 16S rRNA gene sequencing from the excised valve. A 75-yr-old woman was hospitalized due to dyspnea. Echocardiography demonstrated large oscillating vegetation at the aortic valve. Blood culture was negative. She underwent valve replacement and sequencing of the 16S rRNA gene from excised valve identified Bartonella quintana. She was successfully treated with combined use of ceftriaxone and gentamicin.
Journal of Korean medical science 11/2012; 27(11):1433-5. · 0.84 Impact Factor
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ABSTRACT: We report a case of subcutaneous infection in a 55-yr-old Korean diabetic patient who presented with a cystic mass of the ankle. Black fungal colonies were observed after culturing on blood and Sabouraud dextrose agar. On microscopic observation, septated ellipsoidal or cylindrical conidia accumulating on an annellide were visualized after staining with lactophenol cotton blue. The organism was identified as Exophiala salmonis by sequencing of the ribosomal DNA internal transcribed spacer region. Phaeohyphomycosis is a heterogeneous group of mycotic infections caused by dematiaceous fungi and is commonly associated with immunocompromised patients. The most common clinical manifestations of subcutaneous lesions are abscesses or cystic masses. To the best of our knowledge, this is the first reported case in Korea of subcutaneous phaeohyphomycosis caused by E. salmonis that was confirmed by molecular analysis and identification of morphological characteristics. This case suggests that E. salmonis infections are no longer restricted to fish.
Annals of laboratory medicine. 11/2012; 32(6):438-41.
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ABSTRACT: The emergence of antimicrobial resistance threatens the successful treatment of pneumococcal infections. Here we report a case of bacteremic pneumonia caused by an extremely drug-resistant strain of Streptococcus pneumoniae, non-susceptible to at least one agent in all classes but vancomycin and linezolid, posing an important new public health threat in our region.
Journal of clinical microbiology 10/2012; · 4.16 Impact Factor
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Infection Control and Hospital Epidemiology 10/2012; 33(10):1053-5. · 3.67 Impact Factor
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ABSTRACT: The purpose of this study was to compare the turnaround time for liquid culturing and primary anti-tuberculous drug susceptibility testing (DST) performed using the mycobacteria growth indicator tube (MGIT) 960 system (Becton Dickinson, USA) with that for conventional culturing and DST (by the absolute concentration method) performed using solid culture medium and to determine the concordance rates of DST results obtained using these 2 methods.
In this retrospective study, we compared the turnaround times from receiving the request for mycobacterial culture to reporting the DST results before and after the introduction of the MGIT 960 system. Further, we determined the concordance between DST results for isoniazid and rifampin for Mycobacterium tuberculosis isolates obtained using the MGIT 960 system and the absolute concentration method, which was conducted at the Korean Institute of Tuberculosis.
The overall turnaround time for mycobacterial culturing and DST was 27 days for liquid culturing and DST using the MGIT 960 system versus approximately 70 days for culturing on solid medium and DST with the absolute concentration method (P<0.001). There was a good concordance between findings of DST obtained with the 2 methods (97.2%, kappa coefficient=0.855 for rifampin; and 95.6%, kappa coefficient=0.864 for isoniazid), for 1,083 clinical isolates.
The automated MGIT 960 system for culturing and DST of M. tuberculosis was successfully introduced in a hospital laboratory setting in Korea with significant shortening of the turnaround time.
Annals of laboratory medicine. 07/2012; 32(4):264-9.
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ABSTRACT: Increasing multidrug resistance (MDR) among extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EK) is of a great concern, because the therapeutic options are severely limited. Thus, we performed a case-control study to evaluate risk factors for MDR among nosocomial bacteremia caused by ESBL-EK. All adult patients with ESBL-EK bacteremia from January 2009 through December 2010 were identified at our institution. MDR was defined as ESBL-EK that demonstrated in vitro resistance to trimethoprim-sulfamethoxazole (TMP-SMX), fluoroquinolone (FQ), and gentamicin. Case patients were those with an MDR ESBL-EK isolate, and control patients were those with a non-MDR ESBL-EK isolate. Among a total of 123 ESBL-EK isolates (74 [60.2%] E. coli and 49 [39.8%] K. pneumoniae) causing nosocomial bacteremia, 33 (26.8%) cases were due to MDR ESBL-EK. In a univariate analysis, the factors significantly associated with acquisition of MDR ESBL-EK were neutropenia, immunosuppressant use, urinary tract infection, and prior use of antibiotics, especially FQ (all p<0.05). A multivariable analysis showed that a prior receipt of FQ (odds ratio [OR]=2.93; 95% confidence interval [CI]=1.07-8.01; p=0.036), percutaneous tube insertion (OR=4.04; 95% CI=1.56-10.75; p=0.005), and neutropenia (OR=4.22; 95% CI=1.56-11.45; p=0.005) were independent risk factors for MDR among ESBL-EK bacteremia in hospitalized patients. The CTX-M-15 enzyme was predominant in both the MDR ESBL-EK and non-MDR ESBL-EK groups (55% [11/20] vs. 55.6% [15/27]). Our data suggest that strategies designed to reduce MDR in ESBL-EK bacteremia should focus on limiting the use of FQ and minimizing invasive procedures such as tube insertion.
Microbial drug resistance (Larchmont, N.Y.) 06/2012; 18(5):518-24. · 1.99 Impact Factor
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ABSTRACT: Abstract BACKGROUND:Mycobacterium avium and Mycobacterium intracellulare are grouped together as the M. avium complex; however, little is known regarding the clinical impact of this species differentiation. This study compared the clinical features and prognoses of patients with M. avium and M. intracellulare lung disease. METHODS:From 2000 to 2009, a total of 590 patients were newly diagnosed with M. avium complex lung disease: 323 (55%) patients had M. avium lung disease, and 267 (45%) patients had M. intracellulare lung disease. RESULTS:Compared with the patients with M. avium lung disease, the patients with M. intracellulare lung disease were more likely to exhibit the following characteristics: older age (64 vs. 59 years, P = 0.002); a lower body mass index (19.5 vs. 20.6 kg/m(2), P < 0.001); respiratory symptoms such as cough (84 vs. 74%, P = 0.005); a history of previous treatment for tuberculosis (51 vs. 31%, P < 0.001); the fibrocavitary form of the disease (26 vs. 13%, P < 0.001); smear-positive sputum (56 vs. 38%, P < 0.001); antibiotic therapy during the 24 months of follow-up (58% vs. 42%, P < 0.001); and an unfavorable microbiologic response after combination antibiotic treatment (56 vs. 74%, P = 0.001). CONCLUSIONS:Patients with M. intracellulare lung disease exhibited a more severe presentation and had a worse prognosis than patients with M. avium lung disease in terms of disease progression and treatment response. Therefore, species differentiation between M. avium and M. intracellulare may have prognostic and therapeutic implications.
Chest 05/2012; · 5.25 Impact Factor
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ABSTRACT: Vancomycin-intermediate resistance has not been previously reported among sequence type 72 (ST72) methicillin-resistant Staphylococcus aureus (MRSA) isolates of SCCmec type IV (ST72-MRSA-IV), which are distinctive community genotype strains in Korea. We report the first case of vancomycin treatment failure due to development of vancomycin-intermediate resistance in infection caused by an ST72-MRSA-IV isolate.
Journal of clinical microbiology 05/2012; 50(7):2513-4. · 4.16 Impact Factor
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Eun-Jeong Joo,
Doo Ryeon Chung,
Young Eun Ha,
So Yeon Park,
Hyun Ah Kim,
Min Hee Lim,
So Hyun Kim,
Cheol-In Kang, Nam Yong Lee,
Kwan Soo Ko,
Kyong Ran Peck,
Jae-Hoon Song
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ABSTRACT: Community-genotype methicillin-resistant Staphylococcus aureus (MRSA) clones have emerged in the community worldwide and recently have been spreading into the hospitals. To identify predictors of sequence type 72-MRSA-SCCmec type IV (ST72-MRSA-IV) in patients with community-onset (CO) S. aureus infection, a case-control study was conducted among CO S. aureus infections, including healthcare-associated infections.
Eighty-four patients with CO infections caused by ST72-MRSA-IV strains in Korea between 2007 and 2009 were selected as cases. Members of the control group were those with CO methicillin-susceptible S. aureus infections and they were matched by the admission date in a 1 : 1 ratio.
The most common type of infection was skin and soft tissue infection in both groups (48.8% versus 52.4%), followed by pneumonia. Female sex (OR 2.55, 95% CI 1.30-5.04), severe sepsis or septic shock (OR 3.05, 95% CI 1.09-8.55), prior hospitalization within the previous year (OR 2.18, 95% CI 1.10-4.32) and surgical site infection (SSI) (OR 4.63, 95% CI 1.38-15.59) were associated with ST72-MRSA-IV infections in multivariate analyses.
Female sex, SSI, severe sepsis or septic shock and prior hospitalization within the previous year were predictors of ST72-MRSA-IV among patients with CO S. aureus infection.
Journal of Antimicrobial Chemotherapy 04/2012; 67(7):1755-9. · 5.07 Impact Factor
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ABSTRACT: We compared the 16S rRNA gene sequencing results analyzed with the GenBank, EzTaxon, and BIBI databases for blood culture specimens for which identifications were incomplete, conflicting, or unidentifiable using conventional methods. Analyses performed using GenBank combined with EzTaxon (kappa = 0.79) were more discriminative than those using other databases alone or in combination with a second database.
Journal of clinical microbiology 03/2012; 50(5):1792-5. · 4.16 Impact Factor
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ABSTRACT: Respiratory viruses (RVs) are a known cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). In this retrospective study, we focused on the first 28 d after transplantation in pediatric HSCT recipients and showed that a multiplex PCR assay significantly increased RV detection compared with a viral culture method. Among 176 pediatric HSCT recipients, 84 with respiratory symptoms within one yr after HSCT were tested by viral culture or multiplex PCR. Within 28 d after HSCT, nine patients were infected with RVs; the incidence of a first episode of RV infection within 28 d after HSCT was 5.1%. Eight patients recovered without complications. However, one patient died of adenovirus (AdV) pneumonia with pulmonary hemorrhage; the mortality rate of RV infection within 28 d after HSCT was 0.57%. In the nine patients with RV infection, five different types of RV were identified, either alone or with another RV. These were corona virus (CoV), rhinovirus (RhV) and respiratory syncytial virus combined with CoV; AdV combined with RhV; and parainfluenza virus. Viral culture detected only one case of RV infection, while multiplex PCR detected eight, suggesting that screening of respiratory infections using multiplex PCR is better than the conventional culture method.
Clinical Transplantation 03/2012; 26(5):736-40. · 1.67 Impact Factor
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ABSTRACT: The identification of molds in clinical laboratories is largely on the basis of phenotypic criteria, the classification of which can be subjective. Recently, molecular methods have been introduced for identification of pathogenic molds in clinical settings. Here, we employed comparative sequence analysis to identify molds.
A total of 47 clinical mold isolates were used in this study, including Aspergillus and Trichophyton. All isolates were identified by phenotypic properties, such as growth rate, colony morphology, and reproductive structures. PCR and direct sequencing, targeting the internal transcribed spacer (ITS) region, the D1/D2 region of the 28S subunit, and the β-tubulin gene, were performed using primers described previously. Comparative sequence analysis by using the GenBank database was performed with the basic local alignment search tool (BLAST) algorithm.
For Aspergillus, 56% and 67% of the isolates were identified to the species level by using ITS and β-tubulin analysis, respectively. Only D1/D2 analysis was useful for Trichophyton identification, with 100% of isolates being identified to the species level. Performances of ITS and D1/D2 analyses were comparable for species-level identification of molds other than Aspergillus and Trichophyton. In contrast, the efficacy of β-tubulin analysis was limited to genus identification because of the paucity of database information for this gene.
The molecular methods employed in this study were valuable for mold identification, although the different loci used had variable usefulness, according to mold genus. Thus, a tailored approach is recommended when selecting amplification targets for molecular identification of molds.
Annals of laboratory medicine. 03/2012; 32(2):126-32.
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ABSTRACT: Limited clinical information is available regarding community onset infections caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. A case-control study was performed to evaluate the epidemiology and risk factors of these types of infections. A case patient was defined as a person whose clinical sample yielded ESBL-producing E. coli. For each case patient, one control was randomly chosen from a group of outpatients from whom non-ESBL-producing E. coli had been isolated and for whom a clinical sample had been sent to the same laboratory for culturing during the following week. Of 108 cases of ESBL-producing E. coli, 56 (51.9%) were classified as health care associated (HCA). Univariate analysis showed male gender, HCA infection, severe underlying illness, and a prior receipt of antibiotics to be associated with ESBL-producing E. coli. In the multivariate analysis, HCA infection (odds ratio [OR], 3.18; 95% confidence interval [CI], 1.67 to 6.06; P < 0.001) and previous use of antibiotics (OR, 4.88; 95% CI, 2.08 to 11.48; P < 0.001) were found to be significantly associated with the ESBL group. In a multivariate analysis that included each antibiotic, previous use of fluoroquinolone (OR, 7.32; 95% CI, 1.58 to 34.01; P = 0.011) was significantly associated with ESBL-producing E. coli. Of 101 isolates in which ESBLs and their molecular relationships were studied, all isolates produced ESBLs from the CTX-M family (CTX-M-14, 40 isolates; CTX-M-15, 39 isolates; and other members of the CTX-M family, 22 isolates). In conclusion, this study confirms that ESBL-producing E. coli strains are a notable cause of community onset infections in predisposed patients. HCA infection and previous use of fluoroquinolone were significant factors associated with ESBL-producing E. coli in community onset infections.
Journal of clinical microbiology 12/2011; 50(2):312-7. · 4.16 Impact Factor
