Search

Highlights • C. tropicalis fungaemia caused high mortality (52.0%) in patients with multiple co-morbidities and neutropenia. • Reduced susceptibility to azoles was observed (66.1% susceptibility for fluconazole and 43.1% for voriconazole). • Early antifungal treatment may improve outcome, regardless of fluconazole MIC, compared with no treatment within 48 h. ABSTRACT Candida tropicalis is the second most common Candida species causing fungaemia in Taiwan, and decreased susceptibility to fluconazole has been reported. This study analysed the clinical characteristics of adult patients with C. tropicalis fungaemia and the antifungal susceptibilities of isolates at five tertiary hospitals in Taiwan (1 July 2011 to 30 June 2014). A standardised case record form was used retrospectively to collect demographic, clinical and microbiological characteristics, antifungal treatment and outcomes. MICs of non-duplicate isolates were determined using SensititreTM YeastOneTM and were interpreted using cut-off values recommended by the CLSI. A total 248 patients were diagnosed over the study period; 30-day crude mortality was 52.0%. Multivariate analysis showed that high Charlson comorbidity index ≥4 (OR = 2.09, 95% CI 1.22–3.59; P = 0.008), neutropenia (OR = 4.61, 95% CI 1.42–15.00; P = 0.011) and treatment with an azole-based regimen (OR = 0.39, 95% CI 0.17–0.90; P = 0.028) were significantly associated with 30-day mortality. A total of 33.9% of isolates were non-susceptible to fluconazole (MIC 50 , 2 mg/L; MIC 90 , 16 mg/L; MIC range, 0.25 to >256 mg/L), whilst 56.9% to voriconazole (MIC 50 , 0.25 mg/L; MIC 90 , 1 mg/L; MIC range, 0.015 to >8 mg/L) according to CLSI clinical breakpoints. There was no significant correlation between overall mortality and MICs of fluconazole or voriconazole. This study showed high mortality in patients with C. tropicalis fungaemia, and azole-based antifungal treatment could improve outcomes regardless of fluconazole MICs of infecting isolates compared with patients without any treatment within 48 h. [ABSTRACT FROM AUTHOR]

The Clinical and Laboratory Standard Institute ( CLSI) revised the clinical breakpoints ( CBPs) for the azoles and echinocandins against Candida species in 2012. We aimed to report the epidemiology of candidemia and antifungal susceptibility of Candida species and evaluate the impact of new CBPs on antifungal susceptibility in our region. All blood isolates of Candida species were obtained from 2007 to 2012. The minimum inhibitory concentrations of fluconazole, voriconazole, echinocandins and flucytosine against Candida isolates were determined by Sensititre YeastOne system. Differences in susceptibility rates between the CBPs of previous and revised versions of CLSI were examined. Of 709 Candida isolates, the fluconazole-susceptible rate was 96.5% in Candida albicans, 85.8% in Candida tropicalis and 92.1% in Candida parapsilosis by the revised CBPs. Compared with the susceptibility results by previous CBPs, the marked reductions in susceptibility of C. albicans, C. tropicalis and C. parapsilosis to fluconazole, that of C. tropicalis and C. parapsilosis to voriconazole , that of C. tropicalis and Candida glabrata to anidulafungin and that of C. tropicalis, C. glabrata and Candida krusei to caspofungin by revised CBPs were found. In conclusion, Candida albicans and C. parapsilosis remain highly susceptible to fluconazole. The non-susceptible rates of Candida species to azoles and echinocandins increase with interpretation by the revised CBPs. [ABSTRACT FROM AUTHOR]

Background: Patients with invasive infections caused by methicillin-resistant Staphylococcus aureus (MRSA), especially those with an elevated minimal inhibitory concentration (MIC) of vancomycin (VA), are likely to have treatment failure and poor outcomes. The aim of this study was to delineate and correlate the genotypes and phenotypes of clinical VA-intermediate S. aureus (VISA) from invasive infections in Taiwan., Methods: Between 2006 and 2010, a total of 670 non-duplicate MRSA isolates were collected from patients with invasive infections, mostly from blood, as part of a nationwide antimicrobial surveillance program named Tigecycline in vitro Surveillance in Taiwan. Among them, 10 (1.5%) VISA (VA MIC = 4 mg/L) isolates were identified. Molecular typing with staphylococcal cassette chromosome mec (SCCmec), multilocus sequence typing, staphylococcal protein A (spa), mec-associated hypervariable region (dru), accessory gene regulator (agr), and pulse-field gel electrophoresis, and phenotypic analysis including antibiotic susceptibility testing, gene encoding Panton-Valentine leukocidin (pvl), and superantigenic toxin profiles, were analyzed., Results: All but one isolate was defined as molecular health-care-associated MRSA: 6 as SCCmecIII-ST239-spa t037-agrI-dru7 (1 isolate) and dru14 (5 isolates), 2 as SCCmecII-ST5-spa t586-agrII-dru4, and one as SCCmecII-ST89-spa t3520-agrIII-dru7. One isolate was defined as SCCmecIV-ST59-spa t437-agrI-dru8, which was categorized as molecular community-associated MRSA. Five pulsotypes were identified; only one had a positive D-test and 3 were insusceptible to daptomycin (MIC ≧1 mg/L). Five isolates possessed sea-selk-selq, among them 4 belonged to SCCmecIII-ST239-spa t037-agrI., Conclusion: In this study, VISA was rarely isolated from invasive MRSA infections, and most cases harbored limited genotypes and corresponding phenotypes., Competing Interests: Declaration of competing interest None declared., (Copyright © 2021. Published by Elsevier B.V.)

Background: The present study was designed to investigate whether teicoplanin minimum inhibitory concentrations (MICs) of methicillin-resistant Staphylococcus aureus (MRSA) isolates play a role in the prognosis of patient with teicoplanin-treated MRSA bloodstream infection (BSI). Methods: Between 1 January 2006 and 31 December 2009, adult patients with teicoplanin-treated MRSA BSI in two Taiwan medical centers were retrospectively enrolled. Their blood MRSA isolates were submitted for determination of MICs to various antibiotics and multi-locus sequence types. All-cause mortalities on Days 14 and 30, as well as clinical response at the end of teicoplanin therapy were treated as endpoints. Results: Two hundred seventy adult patients were enrolled and 210 blood MRSA isolates were available. Independent risk factors for un-favorable outcome at the end of teicoplanin therapy included septic shock (p < 0.0001) and an elevated C-reactive protein level (p = 0.0064). The independent risk factors for all-cause Day 14 mortality (13.0%) included the presence of auto-immune diseases (p = 0.0235), septic shock (p = 0.0253) and thrombocytopenia (p = 0.0018). The independent risk factors for all-cause Day 30 mortality (26.3%) included age (p = 0.0102), septic shock (p < 0.0001) and thrombocytopenia (p = 0.0059). [ABSTRACT FROM AUTHOR]

Objectives: To investigate the determinants of outcome in patients with persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia. [ABSTRACT FROM PUBLISHER]

Correlation of antimicrobial susceptibility patterns with particular spa types could help physicians select appropriate antibiotics for the treatment of invasive methicillin-resistant Staphylococcus aureus (MRSA) infections. The aim of this study was to investigate invasive MRSA isolates through delineating the molecular typing results and correlating them with antibiotic susceptibility testing results. A total of 670 non-duplicate mecA -positive MRSA isolates from patients with invasive infections were collected from a 5-year nationwide antimicrobial surveillance programme [Tigecycline In vitro Surveillance in Taiwan (TIST)] and 58 spa types were identified among 639 isolates (95.4%) by determining the allelic profile of the spa gene using PCR and nucleotide sequencing. Six major spa types, including spa t002 (n = 103; 15.4%) and t037 (n = 253, 37.8%), were classified as healthcare-associated MRSA (HA-MRSA; 53.1%), while t437 (n = 151; 22.5%), t441 (n = 13; 1.9%), t1081 (n = 19; 2.8%) and t3525 (n = 14; 2.1%) were classified as community-associated MRSA (CA-MRSA; 29.4%). Antimicrobial susceptibility was determined by agar dilution or broth microdilution for various antibiotics, and Etest was also used both for daptomycin and vancomycin. The declining trend in vancomycin minimum inhibitory concentration (MIC) was in parallel with an increasing frequency of CA-MRSA. Antibiotic susceptibility patterns were correlated with particular spa types and this correlation could help physicians select appropriate antibiotics for the treatment of invasive MRSA infections. [ABSTRACT FROM AUTHOR]

The higher 14-day mortality rate for patients with Acinetobacter bacteremia receiving tigecycline appropriately compared to other appropriate antibiotics (36.4% versus 14.2%, P = 0.028) was due to the poor effect of tigecycline for isolates with a minimum inhibitory concentration of 2 μg/mL (63.6% of 11 versus 14.2% of 127, P = 0.001)., (Copyright © 2017. Published by Elsevier B.V.)

Background: The Clinical and Laboratory Standards Institute (CLSI) revised the susceptibility breakpoints of cephalosporins for Enterobacteriaceae in 2010 and 2011. However, there is a lack of clinical data about the correlation of minimum inhibitory concentrations (MICs) and clinical outcome. Data for the distribution of MICs and clinical outcomes were analyzed in this study to evaluate the impact of changes in the CLSI breakpoints on the treatment of Klebsiella pneumoniae bacteremia., Methods: Ninety-seven bacteremic K. pneumoniae isolates from Taichung Veterans General Hospital, Taichung, Taiwan were collected for study during the period 2009-2011. The cefazolin MIC was determined by the broth microdilution method according to the recommendations of the CLSI. The MIC distribution of cefazolin and the clinical responses to definitive cefazolin treatment were analyzed., Results: The modal cefazolin MIC among the 97 isolates was 1 μg/mL and accounted for 73 (75.3%) isolates. There were 18 (18.6%) isolates with a cefazolin MIC of 2 μg/mL. The conventional dosage regimens of cefazolin (1 g every 6 hours or 8 hours) achieved a clinical cure in 70 (97.2%) of 72 patients in the group with a cefazolin MIC ≤1 μg/mL and in 14 (87.5%) of 16 patients in the group with a cefazolin MIC of 2 μg/mL. With the conventional dose, the cumulative clinical cure rate for K. pneumoniae bacteremia with cefazolin MIC ≤2 μg/mL was 95.5% (84/88 patients)., Conclusion: The conventional cefazolin dose still can result in satisfactory clinical cure rates for bacteremic episodes due to K. pneumoniae with cefazolin MIC ≤2 μg/mL, the revised susceptible breakpoint of CLSI 2011., (Copyright © 2014. Published by Elsevier B.V.)

Background: Antimicrobial resistance is a major determinant of Helicobacter pylori treatment failures. We conducted a population-based survey to monitor changing antimicrobial susceptibility of H. pylori isolates in Taiwan, with a focus on combinatorial effects of synergism and the influence of acidity., Methods: H. pylori isolates from endoscopic specimens taken from patients enrolled at two medical centers were obtained between January 2008 and December 2009. Minimum inhibitory concentrations (MICs) were determined by agar dilution and Etest methods. Agar media of varying pH (pH 7.3, 6.0, or 5.0) were used to assess whether acidity influences the bactericidal effects of the agents tested. Time-kill assays were used to assess for synergism between different drug combinations., Results: A total of 176 non-duplicate H. pylori isolates from endoscopic specimens were tested. The following MIC90 (mg/L) (susceptible) results were obtained at neutral pH 7.3: amoxicillin, 0.25 (100%); tetracycline, 0.5 (100%); metronidazole, 32 (67.6%); clarithromycin, 0.25 (90.3%); ciprofloxacin, 1 (92.0%); gemifloxacin, 0.5 (94.9%); levofloxacin, 1 (93.2%); and moxifloxacin, 1 (91.5%). A decrease in pH from 6.0 to 5.0 significantly decreased the antimicrobial activity of levofloxacin and moxifloxacin against H. pylori. For clarithromycin-susceptible isolates, levofloxacin combined with clarithromycin provided both synergistic and bactericidal effects. For clarithromycin-resistant isolates with amoxicillin hypersusceptibility (MIC <0.01 mg/L), levofloxacin with amoxicillin or minocycline had at best additive effect but no bactericidal effects., Conclusion: Amoxicillin, tetracycline, clarithromycin, and fluoroquinolones, but not metronidazole, showed good in vitro anti-H. pylori activity (>90% susceptible). Synergism was only observed for clarithromycin-susceptible isolates. Acidity adversely influenced the antimicrobial activity of levofloxacin against H. pylori., (Copyright © 2012. Published by Elsevier B.V.)