Since vancomycin-resistant enterococci (VRE) were first isolated in Europe, rates of VRE colonization and infection have risen steadily. Today VRE have emerged as important nosocomial pathogens worldwide; hence, it is crucial to understand the underlying mechanism in the spreading of VRE. This article reviews the mechanism of resistance to vanco-mycin and global epidemiology of VRE, as well as the current molecular techniques that are being ap-plied to the epidemiological studies of VRE.
ABSTRACT This work identifies an IS CR1 -related bla CTX-M-14 gene, which has never been reported before, from a clinical isolate of Escherichia coli . The bla CTX-M-14 gene was preceded by an IS CR1 element that was followed by a class 1 integron containing three different insert gene cassettes, i.e., dfrA12 , orfF , and aadA2 .
The Korean Laboratory Accreditation Program (KLAP) by the Korean Society of Laboratory Medicine (KSLM) was started in 1999. We summarized history and achievement of KLAP for the last 8 yr.We analyzed 8 yr data (1999-2006) of historical events, trends of participating laboratories, and scores according to the impact of the question to the outcome of the tests. Inspection check lists are for 'laboratory management', 'clinical chemistry', 'diagnostic hematology', 'clinical microbiology', 'diagnostic immunology', 'transfusion medicine', 'cytogenetics', 'molecular genetics', 'histocompatibility', 'flow cytometry', and 'comprehensive laboratory test verification report'. The laboratories with score 90 or higher got 2-yr certificate and laboratories with score between 60 and 89 got 1-yr certificate. The laboratories with score below 60 failed accreditation.The number of accredited laboratories was 2.4 times higher in 2006 (n=227) than in 1999 (n=96). Inspection check lists have been revised 5 times till 2006. The average accreditation rate was 99.6% during these periods and the 2-yr accreditation rate was 32.4% in 2000, 45.6% in 2001, 53.3% in 2002, 47.3% in 2003, 68.5% in 2004, 37.7% in 2005, and 47.7% in 2006. Number of participants in inspector training workshops increased from 89 in 2000 to 766 in 2006.The KLAP has been in place successfully and stabilized over the past 8 yr. It seemed to enhance the laboratory quality. Efforts for improvement of quality control and inspector training workshops appeared to be in the main contributing factors.
Background The incidence of fungal infections varies among hospitals and between different time periods. We performed a nationwide survey in Korea to in-vestigate the distribution of yeast and mold species recovered from clinical specimens. Methods The distributions of clinical isolates of yeast and mold species obtained from 12 university hospitals between January and December 2011 were evaluated relative to the hospital and specimen type. Results A total of 39,533 fungal isolates (37,847 yeast and 1,686 mold isolates) were obtained. C. albicans was the predominant species (49.4%) among the yeast isolates from all clinical specimens, followed by C. glabrata (7.2%) and C. tropicalis (6.5%). For 5,248 yeast isolates from sterile body fluids, blood was the most common source of yeasts (71.1%), followed by peritoneal fluid (9.4%). Although C. albicans was the predominant species at all but two hospitals, the rate of non-albicans Candida species varied from 71.2% to 40.1%, depending on the hospital. The yeast species recovered most fre-quently from the sterile body fluids was C. albicans (41.7%), followed by C. parapsilosis (17.8%) and C. glabrata (14.4%), while that from non-sterile sites was C. albicans (50.7%), followed by C. glabrata (6.0%) and C. tropicalis (5.5%). For mold-forming fungi, Aspergillus species (62.3%) were most common, followed by Trichophyton species (15.4%). Respiratory specimens were the most common source of molds (39.6%), followed by abscesses/wounds (28.4%) and tissues (17.5%). Conclusion The rank order of distribution for different fungal species varied among hospitals and specimen types. Continual national surveillance programs are essential for identifying possible changes in fungal infection patterns.
Prototheca wickerhamii is an achlorophyllic algae that rarely acts as an opportunistic pathogen in humans. We report the case of a 66-year-old female patient with a history of diabetes mellitus who presented with a pus-like discharge from face, facial redness, and swelling. The patient was admitted to the emergency room with worsening facial pain. Gram staining from pus-like discharge revealed yeast like features; however, an isolated colony on a blood agar plate was not identified using VITEK 2 (Biomerieux) or matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF) using VITEK®MS (Biomerieux). Lactophenol cotton blue staining of the colony revealed characteristic sporangia and endospore features. After performing the protein extraction procedure for filamentous fungi (mold) isolates using ethanol and formic acid, MALDI-TOF MS identified the colony as Prototheca wickerhamii, with 99.9% confidence. This case indicates that Prototheca spp. require specialized sample preparation steps, such as the ethanol/formic acid extraction procedure, for identification using MALDI-TOF MS.
The aim of this study was to investigate the prevalence of plasmid-mediated quinolone resistance (PMQR) and mutations in quinolone resistance-determining regions (QRDRs) of Salmonella and their association with fluoroquinolone susceptibility in Korea.A total of 284 nonduplicated clinical isolates of Salmonella were collected from various clinical specimens at 12 tertiary-care hospitals in Korea. The qnrA, qnrB, and qnrS genes were detected by multiplex polymerase chain reaction (PCR). The qepA and aac(6')-Ib-cr genes were amplified by PCR. The QRDRs of gyrA, gyrB, parC, and parE were amplified by PCR from the DNA of selected nalidixic acid-resistant and qnr-positive isolates.We detected six qnr-positive Salmonella (four qnrS1 and two qnrB19) and one aac(6')-Ib-cr-positive strain. A mutation in the QRDR of gyrA only (N=46) was the most common, followed by gyrA+parC (N=9), parC (N=7), gyrA+parE (N=3), parC+parE (N=3), gyrA+gyrB (N=2), and parE (N=1). There were seven novel mutations in the QRDR regions of gyrB, parC, and parE. Six of seven PMQR-positive isolates had high-level resistance to nalidixic acid, and all six strains had reduced susceptibility to ciprofloxacin. One qnrS1-positive isolate was resistant to ciprofloxacin, norfloxacin, and nalidixic acid. The resistant rates to nalidixic acid, ciprofloxacin, norfloxacin, and levofloxacin were 49.3%, 1.1%, 0.7%, and 0.4%, respectively.We report the first detection of PMQR in Salmonella isolates from Korea. It is essential to continue surveillance and to watch for the spread of PMQR in Salmonella for public health control.
ABSTRACT Six VanB phenotype- vanA genotype isolates of Enterococcus faecium with heterogeneous expression of teicoplanin resistance which gave rise to an outbreak at a Korean tertiary care teaching hospital have IS 1216V in the coding region of vanS . This could be the underlying cause of the VanB phenotype- vanA genotype with heterogeneous expression of teicoplanin resistance.
ABSTRACT The vanA gene cluster is carried as a part of Tn 1546 -like elements. The genetic diversity in Tn 1546 -like elements has been documented previously. The differences described thus far have included the integration of insertion sequence (IS) elements IS 1216V , IS 1251 , IS 1476 , and IS 1542 . Among these, IS 1216V has been reported to be widespread in VanA enterococci of diverse geographic areas, whereas IS 1542 and IS 1476 have been reported only in the United Kingdom and Canada, respectively. We investigated the distribution of ISs among 20 vanA -containing Enterococcus faecium isolates from human patients in nine different university hospitals in Korea. Pulsed-field gel electrophoresis (PFGE) was performed to identify the clonality of the isolates. Moreover, PCR amplification of the internal regions of Tn 1546 was performed for structural analysis of the van gene, and both DNA strands of the PCR amplicons were directly sequenced by the dideoxy termination method. The PFGE patterns revealed a high degree of clonal diversity. Structural analyses of the van gene detected IS 1542 and IS 1216V in the genomes of all 20 isolates, whereas it did not detect IS 1476 or IS 1251 in the genomes of any of the isolates. In addition, IS 19 was detected in the vanS - vanH intergenic region of one isolate. These data indicate that identification of the IS within a vanA gene cluster could be a useful tool in epidemiological investigations. In addition, the distribution of ISs associated with Tn 1546 -like elements among the Korean isolates is therefore similar to that among European vancomycin-resistant enterococci.