Efficacy of cefoperazone/sulbactam for ESBL-producing Escherichia coli and Klebsiella pneumoniae bacteraemia and the factors associated with poor outcomes.

OBJECTIVE: We aimed to assess the efficacy of cefoperazone/sulbactam (CPZ/SUL) in extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales infections and identify factors influencing outcomes. METHODS: This retrospective multicentre study was conducted in Taiwan (January 2015 to December 2020) and examined the efficacy of CPZ/SUL treatment in ESBL-producing Enterobacterales bacteraemia. The minimum inhibitory concentrations (MICs) were determined using agar dilution; ESBL/AmpC genes were detected using polymerase chain reaction. The primary outcome was clinical success, whereas the secondary outcome was 30-day mortality. Clinical success was defined as the complete resolution of clinical signs and symptoms of K. pneumoniae or E. coli infection, with no evidence of persistent or recurrent bacteraemia. The factors influencing outcomes were identified using a multivariate analysis. RESULTS: CPZ/SUL demonstrated a clinical success rate of 82.7% (91/110) in treating ESBL-producing Enterobacterales bacteraemia, with a 30-day mortality rate of 9.1% (10/110). Among 110 ESBL-producing isolates, a high clinical success rate was observed at an MIC of ≤32/32 mg/L. Multivariate analysis revealed that a Charlson comorbidity index (CCI) of ≥6 was associated with lower clinical success [odds ratio (OR): 5.80, 95% confidence interval (CI): 1.15-29.14, P = 0.033]. High Sequential Organ Failure Assessment scores (≥6) were significantly associated with increased 30-day mortality (OR: 14.34, 95% CI: 1.45-141.82, P = 0.023). DISCUSSION: CPZ/SUL demonstrated a clinical success rate of 82.7% (91/110) in treating ESBL-producing Enterobacterales bacteraemia. Treatment success was evident when the CPZ and SUL MIC was ≤32/32 mg/L. Comorbidities (CCI ≥6) were associated with lower clinical success, while disease severity (Sequential Organ Failure Assessment score ≥6) correlated with higher mortality.

Multicenter study on clinical outcomes and poor prognostic factors in patients with Klebsiella pneumoniae bacteremia receiving cefoperazone/sulbactam treatment.

BACKGROUND: Infections caused by Klebsiella pneumoniae are common and result in high mortality rates. In vitro studies demonstrated the potency of cefoperazone/sulbactam (CPZ/SUL) against Klebsiella pneumoniae. However, the clinical efficacy of CPZ/SUL for the treatment of K. pneumoniae bacteremia has not been studied. OBJECTIVES: This study aimed to associate the clinical outcomes of patients with bacteremia with the minimal inhibitory concentrations (MICs) of CPZ/SUL against the causative K. pneumoniae isolates. METHODS: This multicenter, retrospective study was conducted in Taiwan between July 2017 and April 2021. Patients with K. pneumoniae bacteremia treated with CPZ/SUL were enrolled in this study. CPZ/SUL MICs were determined using the agar dilution method. Data on the patients' clinical outcomes and characteristics were collected and analyzed. RESULTS: In total, 201 patients were enrolled. Among the causative K. pneumoniae isolates, 180 (89.5%) were susceptible to CPZ/SUL. Most patients (n = 156, 77.6%) had favorable outcomes. The 30-day mortality rate was 11.9% (n = 24). Multivariate risk analyses showed that higher APACHE II score (Odds Ratio [OR], 1.14; Confidence Interval [CI], 1.07-1.21; p < 0.001), metastatic tumors (OR, 5.76; CI, 2.31-14.40; p < 0.001), and causative K. pneumoniae CPZ/SUL MICs > 16 µg/ml (OR, 4.30; CI, 1.50-12.27; p = 0.006) were independently associated with unfavorable outcomes. CONCLUSION: Patients with K. pneumoniae bacteremia treated with CPZ/SUL at a ratio 1:1 had favorable outcomes when the CPZ/SUL MICs were ≤ 16 µg/ml. Patients with higher APACHE II scores and metastatic tumors had unfavorable outcomes.

Operation and robustness analysis of a star-bus optic fiber sensor network.

This paper proposes a star-bus topology optic fiber sensor network with an efficient mechanism for network communication to accomplish monitoring and protection operations. The master node scans each channel for its healthy conditions with an N * M optical switch, just as in time-division multiplexing, accomplishing a comprehensive monitoring of the whole sensor network. In addition, we analyze the impact of structural parameters on network robustness, then obtain a basic design principle of network topology. We also demonstrate the proposed network's feasibility by multiplexing different fiber sensor systems simultaneously; in addition, an optimized structure is proposed to accomplish the measurement in extreme environments and proved to be effective.

An observational study on prevalence of latent tuberculosis infection and outcome of 3HP treatment in patients under hemodialysis in Taiwan.

BACKGROUND: Identification and treatment for latent tuberculosis infection (LTBI) are of great epidemiological importance of controlling tuberculosis (TB) worldwide. Identification in high-risk population on dialysis and treatment with 12-week weekly rifapentine plus isoniazid (3HP) help improve prevention outcomes effectively. METHODS: We conducted a single-center, nonrandomized follow-up study on end-stage renal disease patients on hemodialysis. The interferon-gamma release assay (IGRA) was used for the diagnosis of LTBI. Participants were treated with 3HP, and treatment responses were recorded and analyzed. RESULTS: A total of 123 of the 641 patients showed positive IGRA results. The male sex, age >60 years, low serum albumin level (<4.0 g/dL), and hypercalcemia (serum calcium level > 10.2 mg/dL) were associated with IGRA positivity. Seventy-five patients were treated with 3HP, with a completion rate of 66.67%. The male sex, albumin level >4.0 g/dL, and absence of adverse drug reaction were associated with increased completion rates. Adverse drug reactions included dizziness, fatigue, nausea and vomiting, fever, and hypertension. CONCLUSION: Risk factors for LTBI in dialysis patients were identified to prioritize LTBI screening and initiate early treatment. The completion rate in dialysis patients were approximately 2 of 3 patients with mild adverse drug reaction, leading to discontinuation of the treatment.

Randomized Noninferiority Trial of Cefoperazone-Sulbactam versus Cefepime in the Treatment of Hospital-Acquired and Healthcare-Associated Pneumonia.

Cefoperazone, a third-generation cephamycin with broad-spectrum antibacterial activity and the ability to permeate bacterial cell membranes, is active against commonly encountered multidrug-resistant pathogens for hospital-acquired pneumonia (HAP) and health care-associated pneumonia (HCAP). To clarify the clinical effects of cefoperazone-sulbactam in the treatment of HAP and HCAP, we conducted an open-label, randomized, noninferiority trial that recruited patients aged ≥18 years suffering HAP/HCAP. Participants were randomly assigned to the cefoperazone-sulbactam (2 g of each per 12 h) or cefepime (2 g per 12 h) arm. Clinical and microbiological responses were evaluated at early posttherapy and test-of-cure visits. Recruited patients were allocated to subpopulations for intent-to-treat (n = 154), per-protocol (n = 147), and safety (n = 166) analyses. Intent-to-treat analysis demonstrated that (i) at the early posttherapy visit, 87.3% of patients receiving cefoperazone-sulbactam and 84.3% of patients receiving cefepime achieved clinical improvement or cure (risk difference of 3.0%; 95% confidence interval [CI], -9.0% to 15.0%), and (ii) at the test-of-cure visit, 73.1% of patients receiving cefoperazone-sulbactam and 56.8% of patients receiving cefepime were assessed as cured (risk difference of 16.3%; 95% CI, 0.0% to 33.0%). These results indicated the noninferiority of cefoperazone-sulbactam to cefepime, which was confirmed by per-protocol analysis. The chest radiographic consolidation/infiltration resolution rate, microbiological eradiation rate, and percentage of adverse events were comparable in both groups. Serious adverse events were rare, and none was judged to be related to the study drugs. Cefoperazone-sulbactam at 2 g every 12 h was noninferior to cefepime at 2 g every 2 h for patients with HCAP.

Viridans streptococcus peritonitis in peritoneal dialysis: clinical characteristics and comparison with concurrent polymicrobial infection.

BACKGROUND: The clinical course of Viridans streptococci (VS) peritonitis in patients undergoing peritoneal dialysis (PD) is rarely reported. This study examined the association of clinical factors with VS peritonitis. METHODS: We retrospectively reviewed clinical data from patients with VS peritonitis from March 1990 to February 2016 in a PD center in Taiwan and evaluated clinical profiles and treatment outcomes. RESULTS: A total of 109 episodes of VS peritonitis in 71 patients identified. Among these patients, 57 had mono-VS peritonitis and 14 had concurrent polymicrobial infections. The median time interval from PD initiation to the first VS peritonitis episode was 18 months (range, 0.6-144 months). Among clinical outcomes, most VS peritonitis episodes were completely cured regardless of a history of peritonitis. All episodes with catheter removal occurred in those without a history of recent antibiotic use. CONCLUSION: VS peritonitis in patients undergoing PD typically has favorable treatment outcomes. Antibiotic therapy should be started promptly.

Teicoplanin therapy for MRSA bacteraemia: a retrospective study emphasizing the importance of maintenance dosing in improving clinical outcomes.

OBJECTIVES: To study the relationship between teicoplanin maintenance dosing and clinical outcomes in adults with MRSA bacteraemia. METHODS: MRSA bacteraemic patients who received three teicoplanin loading doses (6 mg/kg/12 h) followed by maintenance doses of 6 mg/kg/24 h (Group 1) or 6 mg/kg/12 h (Group 2) were retrospectively analysed. Evaluated on day 7, an unfavourable early clinical response referred to the presence of septic shock, persistent fever, persistent leucocytosis and/or persistent bacteraemia. Assessed at completion of teicoplanin therapy, an unfavourable final clinical response referred to clinical treatment failure. RESULTS: Compared with those in Group 1 (n = 122), patients in Group 2 (n = 82) had significantly higher rates of favourable early clinical response (P = 0.040) and final clinical response (P < 0.001) and a lower bloodstream-infection-related mortality rate (P = 0.018). Based on estimated ORs for favourable final clinical response in multivariate analysis, endocarditis (P < 0.001; OR 0.109, 95% CI 0.032-0.368), pneumonia (P < 0.001; OR 0.172, 95% CI 0.069-0.433), ICU admission (P < 0.001; OR 0.132, 95% CI 0.054-0.325) and high Pittsburgh bacteraemia score (P = 0.042; OR 0.187, 95% CI 0.021-0.457) were each a risk factor for an unfavourable final clinical response. Higher teicoplanin maintenance dosing contributed to a favourable final clinical response (P < 0.001; OR 8.800, 95% CI 3.602-21.502). Significantly higher favourable final clinical response rates were also found in patients with endocarditis (P = 0.007) and pneumonia (P < 0.001) in Group 2 compared with their counterparts in Group 1. CONCLUSIONS: These data highlight the importance of higher teicoplanin maintenance dosing, especially for severe infections due to MRSA.

Purification optimization for a recombinant single-chain variable fragment against type 1 insulin-like growth factor receptor (IGF-1R) by using design of experiment (DoE).

Design of experiment (DoE) is a statistics-based technique for experimental design that could overcome the shortcomings of traditional one-factor-at-a-time (OFAT) approach for protein purification optimization. In this study, a DoE approach was applied for optimizing purification of a recombinant single-chain variable fragment (scFv) against type 1 insulin-like growth factor receptor (IGF-1R) expressed in Escherichia coli. In first capture step using Capto L, a 2-level fractional factorial analysis and successively a central composite circumscribed (CCC) design were used to identify the optimal elution conditions. Two main effects, pH and trehalose, were identified, and high recovery (above 95%) and low aggregates ratio (below 10%) were achieved at the pH range from 2.9 to 3.0 with 32-35% (w/v) trehalose added. In the second step using cation exchange chromatography, an initial screening of media and elution pH and a following CCC design were performed, whereby the optimal selectivity of the scFv was obtained on Capto S at pH near 6.0, and the optimal conditions for fulfilling high DBC and purity were identified as pH range of 5.9-6.1 and loading conductivity range of 5-12.5 mS/cm. Upon a further gel filtration, the final purified scFv with a purity of 98% was obtained. Finally, the optimized conditions were verified by a 20-fold scale-up experiment. The purities and yields of intermediate and final products all fell within the regions predicted by DoE approach, suggesting the robustness of the optimized conditions. We proposed that the DoE approach described here is also applicable in production of other recombinant antibody constructs.

Increasing trend of fluconazole-non-susceptible Cryptococcus neoformans in patients with invasive cryptococcosis: a 12-year longitudinal study.

BACKGROUND: This study aimed to investigate the rate of fluconazole-non-susceptible Cryptococcus neoformans in Southern Taiwan for the period 2001-2012 and analyze the risk factors for acquiring it among patients with invasive cryptococcosis. METHODS: All enrolled strains were isolated from blood or cerebrospinal fluid samples of the included patients. If a patient had multiple positive results for C. neoformans, only the first instance was enrolled. Susceptibility testing was performed using the Clinical and Laboratory Standards Institutes M27-A3 broth micro-dilution method. The MIC interpretative criteria for susceptibility to fluconazole were ≤ 8 µg/ml. A total of 89 patients were included. Patients (n = 59) infected by fluconazole-susceptible strains were compared with those (n = 30) infected by non-susceptible strains. The patients' demographic and clinical characteristics were analyzed. RESULTS: The rate of fluconazole-non-susceptible C. neoformans in the study period significantly increased over time (p < 0.001). The C. neoformans isolated in 2011-2012 (odds ratio: 10.68; 95 % confidence interval: 2.87-39.74; p < 0.001) was an independent predictive factor for the acquisition of fluconazole-non-susceptible C. neoformans. CONCLUSIONS: The rate of fluconazole-non-susceptible C. neoformans has significantly increased recently. Continuous and large-scale anti-fungal susceptibility tests for C. neoformans are warranted to confirm this trend.

Use of simple clinical and laboratory predictors to differentiate influenza from dengue and other febrile illnesses in the emergency room.

BACKGROUND: Clinical differentiation of influenza from dengue and other febrile illnesses (OFI) is difficult, and available rapid diagnostic tests have limited sensitivity. METHODS: We conducted a retrospective study to compare clinical and laboratory findings between (i) influenza and dengue and (ii) influenza and OFI. RESULTS: Of 849 enrolled patients, the mean time between illness onset and hospital presentation was 1.7, 3.7, and 3 days for influenza, dengue, and OFI, respectively. Among pediatric patients (≤18 years) (445 influenza, 24 dengue, and 130 OFI), we identified absence of rashes, no leukopenia, and no marked thrombocytopenia (platelet counts <100 × 10(9) cells/L) as predictors to distinguish influenza from dengue, whereas rhinorrhea, malaise, sore throat, and mild thrombocytopenia (platelet counts 100-149 × 10(9)/L) were predictors that differentiated influenza from OFI. Among adults (>18 years) (81 influenza, 124 dengue, and 45 OFI), no leukopenia and no marked thrombocytopenia distinguished influenza from dengue, while rhinorrhea and malaise differentiated influenza from OFI. A diagnostic algorithm developed to distinguish influenza from dengue using rash, leukopenia, and marked thrombocytopenia showed >90% sensitivity to identify influenza in pediatric patients. CONCLUSIONS: This study identified simple clinical and laboratory parameters that can assist clinicians to distinguish influenza from dengue and OFI. These findings may help clinicians diagnose influenza and facilitate appropriate management of affected patients, particularly in resource-poor settings.

Aspirin enhances opsonophagocytosis and is associated to a lower risk for Klebsiella pneumoniae invasive syndrome.

BACKGROUND: Klebsiella pneumoniae (KP) expressing hypermucoviscosity phenotype (HV-KP) has abundant capsular polysaccharide (CPS) and is capable of causing invasive syndrome. Sodium salicylate (SAL) reduces the production of CPS. The study was aimed to investigate the relationship between aspirin usage and KP-mediated invasive syndrome and the effect of SAL on HV-KP. METHODS: Patients with community-acquired KP bacteraemia were prospectively enrolled. KP-M1, a serotype-K1 HV-KP clinical isolate, was used in the following experiments: CPS production, HV-KP phenotype, and the effect of SAL on neutrophils phagocytosis. The effect of oral aspirin intake on the leukocyte bactericidal activity was evaluated. RESULTS: Patients infected by HV-KP and diabetic patients with poor glycemic control were at an increased risk for invasive syndrome (p < 0.01); those who had recent use of aspirin (p = 0.02) were at a lower risk. CPS production was significantly reduced in the presence of SAL. The HV-KP phenotype and resistance to neutrophil phagocytosis were both significantly reduced in the KP-M1 after incubation with SAL (p < 0.01). Aspirin treatment significantly enhanced the killing of KP-M1 by leukocytes (p < 0.01). CONCLUSION: Treatment with SAL significantly reduces CPS production in HV-KP, thereby contributing to leukocyte phagocytosis and bactericidal activity against this pathogen.

Determining delayed admission to intensive care unit for mechanically ventilated patients in the emergency department.

INTRODUCTION: The adverse effects of delayed admission to the intensive care unit (ICU) have been recognized in previous studies. However, the definitions of delayed admission varies across studies. This study proposed a model to define "delayed admission", and explored the effect of ICU-waiting time on patients' outcome. METHODS: This retrospective cohort study included non-traumatic adult patients on mechanical ventilation in the emergency department (ED), from July 2009 to June 2010. The primary outcomes measures were 21-ventilator-day mortality and prolonged hospital stays (over 30 days). Models of Cox regression and logistic regression were used for multivariate analysis. The non-delayed ICU-waiting was defined as a period in which the time effect on mortality was not statistically significant in a Cox regression model. To identify a suitable cut-off point between "delayed" and "non-delayed", subsets from the overall data were made based on ICU-waiting time and the hazard ratio of ICU-waiting hour in each subset was iteratively calculated. The cut-off time was then used to evaluate the impact of delayed ICU admission on mortality and prolonged length of hospital stay. RESULTS: The final analysis included 1,242 patients. The time effect on mortality emerged after 4 hours, thus we deduced ICU-waiting time in ED > 4 hours as delayed. By logistic regression analysis, delayed ICU admission affected the outcomes of 21 ventilator-days mortality and prolonged hospital stay, with odds ratio of 1.41 (95% confidence interval, 1.05 to 1.89) and 1.56 (95% confidence interval, 1.07 to 2.27) respectively. CONCLUSIONS: For patients on mechanical ventilation at the ED, delayed ICU admission is associated with higher probability of mortality and additional resource expenditure. A benchmark waiting time of no more than 4 hours for ICU admission is recommended.

Epidemiology and staphylococcal cassette chromosome mec typing of methicillin-resistant Staphylococcus aureus isolates in Taiwan: A multicenter study.

BACKGROUND/PURPOSE: After community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was identified, new community-onset, healthcare-associated MRSA (HA-MRSA-CO) infections have been noticed as MRSA infection in patients with community-onset infection who have underlying conditions resulting in frequent exposure to the healthcare system. However, previous studies have not thoroughly investigated whether HA-MRSA-CO has characteristics resembling those of CA-MRSA or hospital-onset, healthcare-associated MRSA (HA-MRSA-HO) infection. METHODS: A multicenter, retrospective study was conducted to analyze the clinical and microbiological data of patients with clinical isolates of MRSA from nine hospitals in Taiwan. RESULTS: In total, 203 patients with MRSA isolates, including 27 patients with CA-MRSA (13.3%), 59 with HA-MRSA-CO (29.1%), and 117 with HA-MRSA-HO (57.6%), were studied. Compared to HA-MRSA-HO isolates, the CA-MRSA and HA-MRSA-CO isolates were associated with a higher proportion of skin and soft tissue infections (81.8% and 65.3% vs. 40.5%, p=0.001 and p=0.002) as well as lesser rate of resistance to ciprofloxacin (33.3% and 50.9% vs. 74.4%, p<0.001 and p=0.002), gentamicin (44.4% and 64.4% vs. 84.6%, p<0.001 and p=0.002), and trimethoprim/sulfamethoxazole (33.3% and 42.4% vs. 58.1%, p=0.02 and p=0.048), and a lower 30-day all-cause mortality rate (7.4% and 0% vs. 20.9%, p<0.001). Most of the CA-MRSA isolates were classified as staphylococcal cassette chromosome mec (SCCmec) type VT (11/27, 40.7%), whereas most HA-MRSA-HO isolates were classified as SCCmec type III (66/117, 56.4%). CONCLUSION: The CA-MRSA, HA-MRSA-CO, and HA-MRSA-HO clinical isolates significantly differed in their clinical presentations and molecular characteristics.

Surveillance of pathogenic yeasts in hospital environments in Taiwan in 2020.

BACKGROUND: A predominate azole-resistant Candida tropicalis clade 4 genotype causing candidemia has been detected in not only Taiwan but also China, Singapore, and Australia. It can also be detected on fruit surfaces. In addition to determining distribution and drug susceptibilities of pathogenic yeasts in environments of intensive care units of 25 hospitals in Taiwan, we would also like to investigate whether the azole-resistant C. tropicalis exists in Taiwan's hospital environment. METHODS: The swabs of hospital environments were collected from August to November in 2020 and were cultured for yeasts. The yeasts were identified by rDNA sequence and the antifungal susceptibilities of those isolates were determined by the broth microdilution method. RESULTS: The average yeast-culture rate of hospitals was 9.4% (217/2299). Sinks had the highest yeast-positive culture rate (32.7%), followed by bedside tables (28.9%), floors (26.0%), water-dispenser buttons (23.8%), and TV controller/touch panels (19.0%). Of 262 identified isolates, Candida parapsilosis was the most common species, accounting for 22.1%, followed by Filobasidium uniguttulatum (18.3%), Candida albicans (9.5%), C. tropicalis (8.0%), Candida glabrata (Nakaseomyces glabratus) (6.9%), and 30 other species (35.1%). Of the 21 C. tropicalis isolates from 11 units in 9 hospitals, 15 diploid sequence types (DSTs) were identified. The two DST506 fluconazole-resistant ones belonged to clade 4. CONCLUSION: We detected not only various pathogenic yeast species but also the predominant clade 4 genotype of azole-resistant C. tropicalis. Our findings highlight and re-emphasize the importance of regular cleaning and disinfection practices.

Timing of initiating glycopeptide therapy for methicillin-Resistant Staphylococcus aureus bacteremia: the impact on clinical outcome.

When a Staphylococcus-like organism (SLO) is microscopically found in Gram staining of blood culture (BC) specimen, it seems reasonable to administrate a glycopeptide (GP) for empirical therapy. The paper investigates the risk factors for 14-day mortality in patients with methicillin-resistance Staphylococcus aureus bacteremia (MRSAB) and clarifies the impact of the timing for initiating GP therapy. A retrospective study identifies patients with MRSAB (endocarditis was excluded) between 2006 and 2009. Patients were categorized as receiving GP at the interval before a preliminary BC report indicating the growth of SLO and the onward 24 hours or receiving GP 24 h after a preliminary BC report indicating the growth of SLO. Total 339 patients were enrolled. There was no difference on the 14-day overall or infection-related mortality rates at the time to administer GP. Multivariate analysis disclosed pneumonia (OR = 4.47; of 95% CI; of 2.09-9.58; P < 0.01) and high APACHE II score (OR, 2.81, with 95% CI, 1.19-6.65; P = 0.02) were independent risk factors for infection-related mortality. The mortality rate did not decrease following administrating GP immediately after a preliminary BC indicating SLO growth. An additional research for the optimal timing for initiating GP treatment is warranted.

Increasing trend of healthcare-associated infections due to vancomycin-resistant Enterococcus faecium (VRE-fm) paralleling escalating community-acquired VRE-fm infections in a medical center implementing strict contact precautions: An epidemiologic and pathogenic genotype analysis and its implications.

OBJECTIVE: To clarify whether there were clandestine intra-hospital spreads of vancomycin-resistant Enterococcus faecium (VRE-fm) isolates that led to specific strain of VRE lingering in the hospital and/or developing outbreaks that rendered a progressively increasing trend of healthcare-associated infections due to VRE-fm (VRE-fm-HAIs). SETTING: Despite implementing strict contact precautions for hospitalized patients with VRE-fm-infection/colonization, number of VRE-fm-HAIs in a medical centre in southern Taiwan were escalating in 2009-2019, paralleling an increasing trend of community-acquired VRE-fm- infections. METHODS: We analyzed epidemiologic data and genotypes of non-duplicate VRE-fm isolates each grown from a normally sterile site of 89 patients between December 2016 and October 2018; multilocus sequence typing (MLST) and pulse-field gel electrophoresis (PFGE) typing were performed. RESULTS: Totally 13 sequence types (STs) were found, and the 3 leading STs were ST17 (44％), ST78 (37％), and ST18 (6％); 66 pulsotypes were generated by PFGE. Four VRE-fm isolates grouped as ST17/pulsotype S, 2 as ST17/pulsotype AS, 2 as ST17/pulsotype AU, and 3 as ST78/pulsotype V grew from clinical specimens sampled less than one week apart from patients staying at different wards/departments and/or on different floors of the hospital. CONCLUSIONS: Despite possible small transitory clusters of intra-hospital VRE-fm spreads, there was no specific VRE-fm strain lingering in the hospital leading to increasing trend of VRE-fm-HAIs during the study period. Strict contact precautions were able to curb intra-hospital VRE-fm spreads, but unable to curb the increasing trend of VRE-fm-HAIs with the backdrop of progressively increasing VRE-fm-infections/colorizations in the community.

Trends in the susceptibility of clinically important resistant bacteria to tigecycline: results from the Tigecycline In Vitro Surveillance in Taiwan study, 2006 to 2010.

The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, a nationwide, prospective surveillance during 2006 to 2010, collected a total of 7,793 clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA) (n = 1,834), penicillin-resistant Streptococcus pneumoniae (PRSP) (n = 423), vancomycin-resistant enterococci (VRE) (n = 219), extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (n = 1,141), ESBL-producing Klebsiella pneumoniae (n = 1,330), Acinetobacter baumannii (n = 1,645), and Stenotrophomonas maltophilia (n = 903), from different specimens from 20 different hospitals in Taiwan. MICs of tigecycline were determined following the criteria of the U.S. Food and Drug Administration (FDA) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST-2011). Among drug-resistant Gram-positive pathogens, all of the PRSP isolates were susceptible to tigecycline (MIC(90), 0.03 µg/ml), and only one MRSA isolate (MIC(90), 0.5 µg/ml) and three VRE isolates (MIC(90), 0.125 µg/ml) were nonsusceptible to tigecycline. Among the Gram-negative bacteria, the tigecycline susceptibility rates were 99.65% for ESBL-producing E. coli (MIC(90), 0.5 µg/ml) and 96.32% for ESBL-producing K. pneumoniae (MIC(90), 2 µg/ml) when interpreted by FDA criteria but were 98.7% and 85.8%, respectively, when interpreted by EUCAST-2011 criteria. The susceptibility rate for A. baumannii (MIC(90), 4 µg/ml) decreased from 80.9% in 2006 to 55.3% in 2009 but increased to 73.4% in 2010. A bimodal MIC distribution was found among carbapenem-susceptible A. baumannii isolates, and a unimodal MIC distribution was found among carbapenem-nonsusceptible A. baumannii isolates. In Taiwan, tigecycline continues to have excellent in vitro activity against several major clinically important drug-resistant bacteria, with the exception of A. baumannii.

Agreement assessment of tigecycline susceptibilities determined by the disk diffusion and broth microdilution methods among commonly encountered resistant bacterial isolates: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2008 to 2010.

The Tigecycline In Vitro Surveillance in Taiwan (TIST) study, initiated in 2006, is a nationwide surveillance program designed to longitudinally monitor the in vitro activity of tigecycline against commonly encountered drug-resistant bacteria. This study compared the in vitro activity of tigecycline against 3,014 isolates of clinically important drug-resistant bacteria using the standard broth microdilution and disk diffusion methods. Species studied included methicillin-resistant Staphylococcus aureus (MRSA; n = 759), vancomycin-resistant Enterococcus faecium (VRE; n = 191), extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (n = 602), ESBL-producing Klebsiella pneumoniae (n = 736), and Acinetobacter baumannii (n = 726) that had been collected from patients treated between 2008 and 2010 at 20 hospitals in Taiwan. MICs and inhibition zone diameters were interpreted according to the currently recommended U.S. Food and Drug Administration (FDA) criteria and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. The MIC(90) values of tigecycline against MRSA, VRE, ESBL-producing E. coli, ESBL-producing K. pneumoniae, and A. baumannii were 0.5, 0.125, 0.5, 2, and 8 µg/ml, respectively. The total error rates between the two methods using the FDA criteria were high: 38.4% for ESBL-producing K. pneumoniae and 33.8% for A. baumannii. Using the EUCAST criteria, the total error rate was also high (54.6%) for A. baumannii isolates. The total error rates between these two methods were <5% for MRSA, VRE, and ESBL-producing E. coli. For routine susceptibility testing of ESBL-producing K. pneumoniae and A. baumannii against tigecycline, the broth microdilution method should be used because of the poor correlation of results between these two methods.

Trends in susceptibility of vancomycin-resistant Enterococcus faecium to tigecycline, daptomycin, and linezolid and molecular epidemiology of the isolates: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2006 to 2010.

Among the 219 vancomycin-resistant Enterococcus faecium isolates collected in 20 Taiwanese hospitals from 2006 to 2010, all were susceptible to linezolid and daptomycin, and 98.6% were susceptible to tigecycline. There was a shift toward higher tigecycline MIC values (MIC(90)s) from 2006-2007 (0.06 µg/ml) to 2008-2010 (0.12 µg/ml). The MIC(90)s of daptomycin and linezolid remained stationary. Although pulsotypes among the isolates from the 20 hospitals varied, intrahospital spreading of several clones was identified in 13 hospitals.