Candida parapsilosis: A systematic review to inform the World Health Organization fungal priority pathogens list.

Candida parapsilosis is globally distributed and recognised for causing an increasing proportion of invasive Candida infections. It is associated with high crude mortality in all age groups. It has been particularly associated with nosocomial outbreaks, particularly in association with the use of invasive medical devices such as central venous catheters. Candida parapsilosis is one of the pathogens considered in the WHO priority pathogens list, and this review was conducted to inform the ranking of the pathogen in the list. In this systematic review, we searched PubMed and Web of Science to find studies between 2011 and 2021 reporting on the following criteria for C. parapsilosis infections: mortality, morbidity (hospitalisation and disability), drug resistance, preventability, yearly incidence, and distribution/emergence. We identified 336 potentially relevant papers, of which 51 were included in the analyses. The included studies confirmed high mortality rates, ranging from 17.5% to 46.8%. Data on disability and sequelae were sparse. Many reports highlighted concerns with azole resistance, with resistance rates of >10% described in some regions. Annual incidence rates were relatively poorly described, although there was clear evidence that the proportion of candidaemia cases caused by C. parapsilosis increased over time. While this review summarises current data on C.parapsilosis, there remains an urgent need for ongoing research and surveillance to fully understand and manage this increasingly important pathogen.

Features and global impact of invasive fungal infections caused by Pneumocystis jirovecii: A systematic review to inform the World Health Organization fungal priority pathogens list.

This systematic review evaluates the current global impact of invasive infections caused by Pneumocystis jirovecii (principally pneumonia: PJP), and was carried out to inform the World Health Organization Fungal Priority Pathogens List. PubMed and Web of Science were used to find studies reporting mortality, inpatient care, complications/sequelae, antifungal susceptibility/resistance, preventability, annual incidence, global distribution, and emergence in the past 10 years, published from January 2011 to February 2021. Reported mortality is highly variable, depending on the patient population: In studies of persons with HIV, mortality was reported at 5%-30%, while in studies of persons without HIV, mortality ranged from 4% to 76%. Risk factors for disease principally include immunosuppression from HIV, but other types of immunosuppression are increasingly recognised, including solid organ and haematopoietic stem cell transplantation, autoimmune and inflammatory disease, and chemotherapy for cancer. Although prophylaxis is available and generally effective, burdensome side effects may lead to discontinuation. After a period of decline associated with improvement in access to HIV treatment, new risk groups of immunosuppressed patients with PJP are increasingly identified, including solid organ transplant patients.

Candida auris-a systematic review to inform the world health organization fungal priority pathogens list.

The World Health Organization (WHO) in 2022 developed a fungal priority pathogen list. Candida auris was ultimately ranked as a critical priority pathogen. PubMed and Web of Science were used to find studies published from 1 January 2011 to 18 February 2021, reporting on predefined criteria including: mortality, morbidity (i.e., hospitalization and disability), drug resistance, preventability, yearly incidence, and distribution/emergence. Thirty-seven studies were included in the final analysis. The overall and 30-day mortality rates associated with C. auris candidaemia ranged from 29% to 62% and 23% to 67%, respectively. The median length of hospital stay was 46-68 days, ranging up to 140 days. Late-onset complications of C. auris candidaemia included metastatic septic complications. Resistance rates to fluconazole were as high as 87%-100%. Susceptibility to isavuconazole, itraconazole, and posaconazole varied with MIC90 values of 0.06-1.0 mg/l. Resistance rates to voriconazole ranged widely from 28% to 98%. Resistance rates ranged between 8% and 35% for amphotericin B and 0%-8% for echinocandins. Over the last ten years, outbreaks due to C. auris have been reported in in all WHO regions. Given the outbreak potential of C. auris, the emergence and spread of MDR strains, and the challenges associated with its identification, and eradication of its environmental sources in healthcare settings, prevention and control measures based on the identified risk factors should be evaluated for their effectiveness and feasibility. Global surveillance studies could better inform the incidence rates and distribution patterns to evaluate the global burden of C. auris infections.

Histoplasmosis: A systematic review to inform the World Health Organization of a fungal priority pathogens list.

Histoplasmosis, a significant mycosis primarily prevalent in Africa, North and South America, with emerging reports globally, poses notable health challenges, particularly in immunocompromised individuals such as people living with HIV/AIDS and organ transplant recipients. This systematic review, aimed at informing the World Health Organization's Fungal Priority Pathogens List, critically examines literature from 2011 to 2021 using PubMed and Web of Science, focusing on the incidence, mortality, morbidity, antifungal resistance, preventability, and distribution of Histoplasma. We also found a high prevalence (22%-44%) in people living with HIV, with mortality rates ranging from 21% to 53%. Despite limited data, the prevalence of histoplasmosis seems stable, with lower estimates in Europe. Complications such as central nervous system disease, pulmonary issues, and lymphoedema due to granuloma or sclerosis are noted, though their burden remains uncertain. Antifungal susceptibility varies, particularly against fluconazole (MIC: ≥32 mg/l) and caspofungin (MICs: 4-32 mg/l), while resistance to amphotericin B (MIC: 0.125-0.16 mg/l), itraconazole (MICs: 0.004-0.125 mg/l), and voriconazole (MICs: 0.004-0.125 mg/l) remains low. This review identifies critical knowledge gaps, underlining the need for robust, globally representative surveillance systems to better understand and combat this fungal threat.

Changing Epidemiology of Pathogenic Bacteria Over the Past 20 Years in Korea.

BACKGROUND: The epidemiology of pathogenic bacteria varies according to the socioeconomic status and antimicrobial resistance status. However, longitudinal epidemiological studies to evaluate the changes in species distribution and antimicrobial susceptibility of pathogenic bacteria nationwide are lacking. We retrospectively investigated the nationwide trends in species distribution and antimicrobial susceptibility of pathogenic bacteria over the last 20 years in Korea. METHODS: From 1997 to 2016, annual cumulative antimicrobial susceptibility and species distribution data were collected from 12 university hospitals in five provinces and four metropolitan cities in South Korea. RESULTS: The prevalence of Staphylococcus aureus was the highest (13.1%) until 2012 but decreased to 10.3% in 2016, consistent with the decrease in oxacillin resistance from 76.1% in 2008 to 62.5% in 2016. While the cefotaxime resistance of Escherichia coli increased from 9.0% in 1997 to 34.2% in 2016, E. coli became the most common species since 2013, accounting for 14.5% of all isolates in 2016. Pseudomonas aeruginosa and Acinetobacter baumannii rose to third and fifth places in 2008 and 2010, respectively, while imipenem resistance increased from 13.9% to 30.8% and 0.7% to 73.5% during the study period, respectively. Streptococcus agalactiae became the most common pathogenic streptococcal species in 2016, as the prevalence of Streptococcus pneumoniae decreased since 2010. During the same period, pneumococcal penicillin susceptibility decreased to 79.0%, and levofloxacin susceptibility of S. agalactiae decreased to 77.1% in 2016. CONCLUSION: The epidemiology of pathogenic bacteria has changed significantly over the past 20 years according to trends in antimicrobial resistance in Korea. Efforts to confine antimicrobial resistance would change the epidemiology of pathogenic bacteria and, consequently, the diagnosis and treatment of infectious diseases.

Fungal Endophthalmitis Outbreak after Cataract Surgery, South Korea, 2020.

In November 2020, an unusual increase in fungal endophthalmitis cases after cataract surgery was reported to the Korea Disease Control and Prevention Agency, South Korea. We initiated an outbreak investigation to identify the cause. We identified 156 cases nationwide, 62 confirmed and 94 probable. Most case-patients were exposed during surgery to ocular viscoelastic devices (OVDs) from the same manufacturer (company A). We isolated Fusarium spp. from 50 confirmed cases. Molecular identification of 39 fungal isolates from clinical samples and 13 isolates from OVDs confirmed F. oxysporum caused the infections. The risk ratio for fungal endophthalmitis from company A's OVDs was 86.0 (95% CI 27.4-256.9), much higher than risk from other manufacturers' products. We determined this fungal endophthalmitis outbreak was caused by a contaminated lot of OVDs and recommended discontinued use of this product. Early recognition of outbreaks and joint responses from related government agencies can reduce risk for fungal endophthalmitis.

Evolution of Fluconazole Resistance Mechanisms and Clonal Types of Candida parapsilosis Isolates from a Tertiary Care Hospital in South Korea.

We investigated the evolution of fluconazole resistance mechanisms and clonal types of Candida parapsilosis isolates from a tertiary care hospital in South Korea. A total of 45 clinical isolates, including 42 collected between 2017 and 2021 and 3 collected between 2012 and 2013, were subjected to antifungal susceptibility testing, sequencing of fluconazole resistance genes (ERG11, CDR1, TAC1, and MRR1), and microsatellite typing. Twenty-two isolates carried Y132F (n = 21; fluconazole MIC = 2 to >256 mg/L) or Y132F+R398I (n = 1; fluconazole MIC = 64 mg/L) in ERG11 and four isolates harbored N1132D in CDR1 (fluconazole MIC = 16 to 64 mg/L). All 21 Y132F isolates exhibited similar microsatellite profiles and formed a distinct group in the dendrogram. All four N1132D isolates displayed identical microsatellite profiles. Fluconazole MIC values of the Y132F isolates varied depending on their MRR1 mutation status (number of isolates, year of isolation, and MIC): K177N (n = 8, 2012 to 2020, 2 to 8 mg/L); K177N + heterozygous G982R (n = 1, 2017, 64 mg/L); K177N + heterozygous S614P (n = 2, 2019 to 2020, 16 mg/L); and K177N + homozygous S614P (n = 10, 2020 to 2021, 64 to > 256 mg/L). Our study revealed that Y132F in ERG11 and N1132D in CDR1 were the major mechanisms of fluconazole resistance in C. parapsilosis isolates. Furthermore, our results suggested that the clonal evolution of Y132F isolates persisting and spreading in hospital settings for several years occurred with the acquisition of heterozygous or homozygous MRR1 mutations associated with a gradual increase in fluconazole resistance.

Performance assessment of ASTA MicroIDSys, a new matrix assisted laser desorption ionization-time of flight mass spectrometry system, for identification of viridans group streptococci.

The performance of the ASTA MicroIDSys system (ASTA), a new matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) system, was evaluated for the identification of viridans group streptococci (VGS) and compared with the results obtained with the Bruker Biotyper system (Bruker Daltonics). A total of 106 Streptococcus reference strains belonging to 24 species from the bacterial strain bank was analyzed using the two MALDI-TOF MS systems. Of the 106 reference strains tested, ASTA MicroIDSys and Bruker Biotyper correctly identified 84.9% and 81.1% at the species level, 100% and 97.2% at the group level and 100% and 98.1% at the genus level, respectively. The difference between the two systems was not statistically significant (P = 0.289). Out of 24 species, 13 species were accurately identified to the species level with 100% accurate identification rates with both systems. The accurate identification rates at the species level of ASTA MicroIDSys and Bruker Biotyper were 100% and 87.5% for the S. anginosus group; 78.4% and 73.5% for the S. mitis group; 91.7% and 91.7% for the S. mutans group; and 100% and 100% for the S. salivarius group, respectively. The ASTA MicroIDSys showed an identification performance equivalent to that of the Bruker Biotyper for VGS. Therefore, it would be useful for the identification of VGS strains in clinical microbiology laboratories.

Evaluation of Two Commercial Broth Microdilution Methods Using Different Interpretive Criteria for the Detection of Molecular Mechanisms of Acquired Azole and Echinocandin Resistance in Four Common Candida Species.

The abilities of the new Vitek 2 AST-YS08 (YS08) and Sensititre YeastOne (SYO) systems to detect the resistances of Candida isolates to azoles and echinocandins were evaluated. In total, 292 isolates, including 28 Candida albicans (6 Erg11 and 2 Fks mutants), 57 Candida parapsilosis (26 Erg11 mutants), 24 Candida tropicalis (10 Erg11 and 1 Fks mutants), and 183 Candida glabrata (39 Pdr1 and 13 Fks mutants) isolates, were tested. The categorical agreements (CAs) between the Clinical and Laboratory Standards Institute (CLSI) method and YS08 fluconazole MICs obtained using clinical breakpoints were 92.4% (C. albicans), 96.5% (C. parapsilosis), and 87.0% (C. tropicalis), and the CAs between the CLSI and SYO MICs were 92.3% (C. albicans), 77.2% (C. parapsilosis), 100% (C. tropicalis), and 98.9% (C. glabrata). For C. glabrata, the CAs with the CLSI micafungin MICs were 92.4% and 55.5% for the YS08 micafungin and caspofungin MICs, respectively; they were 100%, 95.6%, and 98.9% for the SYO micafungin, caspofungin, and anidulafungin MICs, respectively. YS08 does not provide fluconazole data for C. glabrata; the CA with the CLSI fluconazole MIC was 97.8% for the YS08 voriconazole MIC, using an epidemiological cutoff value (ECV) of 0.5 µg/ml. Increased CAs with the CLSI MIC were observed for the YS08 MIC using CLSI ECVs (for fluconazole and C. tropicalis, 100%; for micafungin and C. glabrata, 98.9%) and for the SYO MIC using method-specific ECVs (for fluconazole and C. parapsilosis, 91.2%; for caspofungin and C. glabrata, 98.9%). Therefore, the YS08 and SYO systems may have different abilities to detect mechanisms of azole and echinocandin resistance in four Candida species; the use of method-specific ECVs may improve the performance of both systems.

Impact of vanA-Positive Enterococcus faecium Exhibiting Diverse Susceptibility Phenotypes to Glycopeptides on 30-Day Mortality of Patients with a Bloodstream Infection.

This study was performed to evaluate the impacts of vanA positivity of Enterococcus faecium exhibiting diverse susceptibility phenotypes to glycopeptides on clinical outcomes in patients with a bloodstream infection (BSI) through a prospective, multicenter, observational study. A total of 509 patients with E. faecium BSI from eight sentinel hospitals in South Korea during a 2-year period were enrolled in this study. Risk factors of the hosts and causative E. faecium isolates were assessed to determine associations with the 30-day mortality of E. faecium BSI patients via multivariable logistic regression analyses. The vanA gene was detected in 35.2% (179/509) of E. faecium isolates; 131 E. faecium isolates exhibited typical VanA phenotypes (group vanA-VanA), while the remaining 48 E. faecium isolates exhibited atypical phenotypes (group vanA-atypical), which included VanD (n = 43) and vancomycin-variable phenotypes (n = 5). A multivariable logistic regression indicated that vanA positivity of causative pathogens was independently associated with the increased 30-day mortality rate in the patients with E. faecium BSI; however, there was no significant difference in survival rates between the patients of the vanA-VanA and vanA-atypical groups (log rank test, P = 0.904). A high 30-day mortality rate was observed in patients with vanA-positive E. faecium BSIs, and vanA positivity of causative E. faecium isolates was an independent risk factor for early mortality irrespective of the susceptibility phenotypes to glycopeptides; thus, intensified antimicrobial stewardship is needed to improve the clinical outcomes of patients with vanA-positive E. faecium BSI.

Case report: nosocomial fungemia caused by Candida diddensiae.

BACKGROUND: Candida diddensiae, a yeast found in olive oil, is considered non-pathogenic to humans. Here, we describe the first case of fungemia caused by C. diddensiae in a hospitalized patient with underlying diseases. CASE PRESENTATION: A 62-year-old woman was admitted because of multiple contusions due to repeated falls and generalized weakness. She presented with chronic leukopenia due to systemic lupus erythematosus, and multiple cranial nerve neuropathies due to a recurring chordoma. She was given a lipid emulsion containing total parenteral nutrition (TPN) starting on the day of admission. Broad-spectrum antibiotics had been administered during her last hospital stay and from day 8 of this hospitalization. However, no central venous catheter was used during this hospital stay. Blood cultures obtained on hospital days 17, 23, and 24 yielded the same yeast, which was identified as C. diddensiae via sequence analyses of the internal transcribed spacer region and D1/D2 regions of the 26S ribosomal DNA of the rRNA gene. In vitro susceptibility testing showed that the minimum inhibitory concentration of fluconazole for all isolates was 8 µg/mL. On day 23, TPN was discontinued and fluconazole therapy was started. Blood cultures obtained on day 26 were negative. The fluconazole therapy was replaced with micafungin on day 26 and the patient exhibited improvements. CONCLUSION: The use of lipid TPN may potentially contribute to the occurrence of nosocomial fungemia by C. diddensiae, an unusual Candida species.

Xpert MTB/RIF Assay as a Substitute for Smear Microscopy in an Intermediate-Burden Setting.

RATIONALE: Use of Xpert MTB/RIF assay as a substitute for smear microscopy in routine clinical practice remains unexplored in an intermediate-tuberculosis-burden setting. OBJECTIVES: To compare the diagnostic performance of Xpert and smear microscopy, based on sampling time and location, correlation of Xpert semiquantitative category with smear grade and time to culture positivity, and compliance of reporting time with defined standard time. METHODS: Consecutive sputum samples collected from 2,952 suspected pulmonary tuberculosis patients over a 3-year period were tested by Xpert, smear microscopy, and liquid culture as part of routine diagnostics in South Korea. MEASUREMENTS AND MAIN RESULTS: Based on the analysis of a single sputum specimen per patient, of 2,952 samples, 263 (8.9%) were culture-confirmed tuberculosis and 265 (9.0%) were nontuberculous mycobacteria. The overall sensitivity and specificity were 74.1% and 97.5% for Xpert versus 38.8% and 96.7% for smear microscopy, respectively (P < 0.0001; P > 0.05). Of 82 smear-positive nontuberculous mycobacteria, 81 (98.8%) were accurately excluded by Xpert. Sampling time and location significantly affected the performance of smear microscopy but not that of Xpert. Xpert semiquantitative category strongly correlated with smear grade (γGoodman-Kruskal = 0.982; P < 0.0001) and time to culture positivity (γGoodman-Kruskal = -0.962; P < 0.0001). Median reporting time and its compliance rate within 24 hours were 3.1 hours and 96.3% for Xpert versus 19.1 hours and 88.7% for smear microscopy, respectively (P < 0.0001; P < 0.05). CONCLUSIONS: Xpert provides faster, more stable, and superior results compared with smear microscopy, in addition to its strong correlation with smear grade. Xpert might replace smear microscopy as the first-line diagnostic test for pulmonary tuberculosis in routine clinical practice in an intermediate-burden setting.

Molecular Detection and Subtyping of Human Blastocystis and the Clinical Implications: Comparisons between Diarrheal and Non-diarrheal Groups in Korean Populations.

Blastocystis has recently been recognized as the most common eukaryotic microbe of the human gut. We investigated the prevalence of Blastocystis and their subtypes in diarrheal and non-diarrheal groups and the associated clinical parameters. A total of 324 stool samples were obtained from 196 diarrheal and 128 non-diarrheal subjects. Blastocystis subtypes were determined by sequencing the small subunit ribosomal DNA (SSU rRNA) gene. Demographic, clinical and laboratory data were collected and analyzed by diarrhea and Blastocystis status. The overall rate of Blastocystis positivity was 9.0% (29/324) but was significantly higher in the non-diarrheal group (18.0% vs. 3.1%, P<0.0001). Of the 6 Blastocystis-positive diarrheal patients, 3 (50.0%), none (0.0%), 2 (33.3%), and 1 (16.7%) were infected with subtypes ST1, ST2, ST3, and multiple subtypes, respectively. Of the 23 Blastocystis-positive non-diarrheal patients, 4 (17.4%), 1 (4.3%), and 18 (78.3%) were infected with subtypes ST1, ST2, and ST3, respectively. Blastocystis was less common in the diarrheal than the non-diarrheal group (odds ratio, 0.144; 95% confidence interval, 0.057-0.365, P<0.001). Of the 3 subtypes, ST3 was more frequently observed in the non-diarrheal than diarrheal group (78.3% vs. 33.3%, P=0.0341). Collectively, Blastocystis was found in both the diarrheal and non-diarrheal groups and ST3 was the most common subtype in Korea.

Microsatellite Typing and Resistance Mechanism Analysis of Voriconazole-Resistant Aspergillus flavus Isolates in South Korean Hospitals.

A recent surveillance study in South Korea revealed that 14% (7/50) of Aspergillus flavus clinical isolates had a voriconazole minimum inhibitory concentration of ≥4 µg/ml. Of seven non-wild-type (non-WT) isolates, six ear isolates from four hospitals shared the same microsatellite genotype. None of the non-WT isolates showed cyp51 mutations associated with azole resistance. However, the mean expression levels of efflux pump (MDR2, atrF, and mfs1) and target (cyp51A) genes exhibited significant differences between non-WT and other isolates.

Toxic Shock Syndrome Toxin 1-Producing Methicillin-Resistant Staphylococcus aureus of Clonal Complex 5, the New York/Japan Epidemic Clone, Causing a High Early-Mortality Rate in Patients with Bloodstream Infections.

This study was performed to evaluate the clinical impacts of putative risk factors in patients with Staphylococcus aureus bloodstream infections (BSIs) through a prospective, multicenter, observational study. All 567 patients with S. aureus BSIs that occurred during a 1-year period in six general hospitals were included in this study. Host- and pathogen-related variables were investigated to determine risk factors for the early mortality of patients with S. aureus BSIs. The all-cause mortality rate was 15.0% (85/567) during the 4-week follow-up period from the initial blood culture, and 76.5% (65/85) of the mortality cases occurred within the first 2 weeks. One-quarter (26.8%, 152/567) of the S. aureus blood isolates carried the tst-1 gene, and most (86.2%, 131/152) of them were identified to be clonal complex 5 agr type 2 methicillin-resistant S. aureus (MRSA) strains harboring staphylococcal cassette chromosome mec type II, belonging to the New York/Japan epidemic clone. A multivariable logistic regression showed that the tst-1 positivity of the causative S. aureus isolates was associated with an increased 2-week mortality rate both in patients with S. aureus BSIs (adjusted odds ratio [aOR], 1.62; 95% confidence interval [CI], 0.90 to 2.88) and in patients with MRSA BSIs (aOR, 2.61; 95% CI, 1.19 to 6.03). Two host-related factors, an increased Pitt bacteremia score and advanced age, as well as a pathogen-related factor, carriage of tst-1 by causative MRSA isolates, were risk factors for 2-week mortality in patients with BSIs. Careful management of patients with BSIs caused by the New York/Japan epidemic clone is needed to improve clinical outcomes.

Prospective Observational Study of the Clinical Prognoses of Patients with Bloodstream Infections Caused by Ampicillin-Susceptible but Penicillin-Resistant Enterococcus faecalis.

The purpose of this study was to evaluate the clinical impacts of ampicillin-susceptible but penicillin-resistant (ASPR) phenotypes of Enterococcus faecalis on clinical outcomes in patients with bloodstream infection (BSI). A total of 295 patients with an E. faecalis BSI from six sentinel hospitals during a 2-year period (from May 2016 to April 2018) were enrolled in this study. Putative risk factors, including host-, treatment-, and pathogen-related variables, were assessed to determine the associations with the 30-day mortality rate of patients with an E. faecalis BSI. The proportion of ASPR E. faecalis isolates was 22.7% (67/295). ASPR isolates (adjusted odds ratio, 2.27; 95% confidence interval, 1.01 to 5.02) exhibited a significant association with an increased 30-day mortality rate, and a significant difference in survival was identified in a group of patients treated with ampicillin- and/or piperacillin-based regimens who were stratified according to the penicillin susceptibility of the causative pathogen (P = 0.011 by a log rank test). ASPR E. faecalis BSIs resulted in a >2-fold-higher 30-day mortality rate (26.9%; 18/67) than for the BSIs caused by penicillin-susceptible strains (12.3%; 28/228). The differences in mortality rates of patients stratified by penicillin susceptibility were likely due to the treatment failures of ampicillin and/or piperacillin in patients with an ASPR E. faecalis BSI.

Candida auris Clinical Isolates from South Korea: Identification, Antifungal Susceptibility, and Genotyping.

Candida auris is an emerging worldwide fungal pathogen. Over the past 20 years, 61 patient isolates of C. auris (4 blood and 57 ear) have been obtained from 13 hospitals in Korea. Here, we reanalyzed those molecularly identified isolates using two matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems, including Biotyper and Vitek MS, followed by antifungal susceptibility testing, sequencing of the ERG11 gene, and genotyping. With a research-use-only (RUO) library, 83.6% and 93.4% of the isolates were correctly identified by Biotyper and Vitek MS, respectively. Using an in vitro diagnostic (IVD) library of Vitek MS, 96.7% of the isolates were correctly identified. Fluconazole-resistant isolates made up 62.3% of the isolates, while echinocandin- or multidrug-resistant isolates were not found. Excellent essential (within two dilutions, 96.7%) and categorical agreements (93.4%) between the Clinical and Laboratory Standards Institute (CLSI) and Vitek 2 (AST-YS07 card) methods were observed for fluconazole. Sequencing ERG11 for all 61 isolates revealed that only 3 fluconazole-resistant isolates showed the Erg11p amino acid substitution K143R. All 61 isolates showed identical multilocus sequence typing (MLST). Pulsed-field gel electrophoresis (PFGE) analyses revealed that both blood and ear isolates had the same or similar patterns. These results show that MALDI-TOF MS and Vitek 2 antifungal susceptibility systems can be reliable diagnostic tools for testing C. auris isolates from Korean hospitals. The Erg11p mutation was seldom found among Korean isolates of C. auris, and multidrug resistance was not found. Both MLST and PFGE analyses suggest that these isolates are genetically similar.

Mortality dynamics of Pseudomonas aeruginosa bloodstream infections and the influence of defective OprD on mortality: prospective observational study.

BACKGROUND: To assess the mortality dynamics of patients with Pseudomonas aeruginosa bloodstream infections (BSIs) and the influence of OprD deficiencies of the microorganism on early mortality. METHODS: A prospective multicentre observational study was conducted with 120 patients with P. aeruginosa BSIs occurring between May 2016 and April 2017 in six general hospitals in South Korea. PCR and sequencing were carried out to identify the alterations in oprD and the presence of virulence factors. Cox regression was used to estimate the risk factors for mortality at each timepoint and Kaplan-Meier survival analyses were performed to determine the mortality dynamics. RESULTS: During the 6 week follow-up, 10.8% (13/120) of the patients with P. aeruginosa BSIs died in 2 weeks, 14.2% (17/120) in 4 weeks and 20.0% (24/120) in 6 weeks, revealing a steep decrease in cumulative survival between the fourth and sixth weeks. ICU admission and SOFA score were risk factors for mortality in any weeks after BSI onset and causative OprD-defective P. aeruginosa had a risk tendency for mortality within 6 weeks. Among the 120 P. aeruginosa blood isolates, 14 were XDR, nine produced either IMP-6 or VIM-2 MBL, and 21 had OprD deficiency. CONCLUSIONS: BSIs caused by OprD-defective P. aeruginosa resulted in a 2-fold higher 6 week mortality rate (33.3%) than that of BSIs caused by OprD-intact P. aeruginosa (17.2%), likely due to the decreased susceptibility to carbapenems and bacterial persistence in clinical settings.

Antimicrobial resistance and virulence factors of Klebsiella pneumoniae affecting 30 day mortality in patients with bloodstream infection.

Objectives: To investigate the risk factors of patients with Klebsiella pneumoniae (KP) bloodstream infection (BSI) with a focus on antimicrobial resistance and virulence factors. Methods: All KP BSI patients (n = 579) from six general hospitals during a 1 year period were included in this study. The risk factors of hosts and causative KP isolates were assessed to determine associations with the 30 day mortality of KP BSI patients by multivariate Cox hazards modelling. Results: The 30 day mortality rate of KP BSI patients was 16.9% (98/579). Among the host-associated factors, increased SOFA score and leucopenia status exhibited strong associations with increased 30 day mortality. Among the pathogenic factors, carriage of the pks gene cluster (adjusted HR 1.80; 95% CI 1.16-2.79) was a risk factor, especially when accompanied by MDR. In this regard, KP isolates of the wzi50 capsular type (n = 22) frequently harboured pks (63.6%, 14/22) and ybtA (68.2%, n = 15) and mostly exhibited MDR (63.6%, n = 14), resulting in increased 30 day mortality. In contrast, hypermucoviscous KP isolates showed an inverse association with 30 day mortality (adjusted HR 0.55; 95% CI 0.33-0.90). Conclusions: Despite the reported virulence of hypermucoviscous KP strains, they were associated with good prognoses in KP BSI patients. Importantly, carriage of the pks gene cluster, which is responsible for the synthesis of colibactin, was a relevant marker of early mortality.

A co-infection case report of Taenia saginata in a patient with subclinical clonorchiasis confirmed by the combination of diagnostic tools.

BACKGROUND: Clonorchiasis is the common parasitic infection in the general population of the Republic of Korea, however, taeniasis is scarcely reported recently. Here, we describe a case of co-infection with the cestode T. saginata in a patient with subclinical clonorchiasis diagnosed by a combination of diagnostic tools in Korea. CASE PRESENTATION: A 56-year-old man visited the hospital having passed proglottids in his stool for the past two months and brought a stool sample with segments to our hospital. He had no abdominal symptoms, such as nausea, vomiting, abdominal pain, diarrhea, or constipation. He used to consume raw beef and fish frequently. We could not find evidence of gravid proglottids which contain fully developed uteri filled with ova or branched uterine structures, within the submitted sample. To identify the tapeworm species, we carried out molecular analyses on the proglottids. The cox1 and ef1a sequences had a 100% match with those of T. saginata and differed from the sequences of the other Taenia species. Upon examination of stool samples fixed by formalin-ether concentration method, no Taenia species ova were observed in 10 slides. Instead, C. sinensis ova were observed, despite the level of IgG specific to C. sinensis being within the normal range. The patient was treated with praziquantel (25 mg/kg, three times a day) for 3 days, and subsequently C. sinensis ova were not found in his stool. CONCLUSION: Our case indicates that a combination of morphological, serological, and molecular diagnostic tools should be used for the accurate diagnosis of subclinical parasitic infections.