Clinical and microbiological evaluation of ventilator-associated pneumonia in an intensive care unit in Vietnam.

Background: The increasing incidence of multidrug-resistant Gram-negative bacteria causing ventilator-associated pneumonia (VAP) is a global concern. A better understanding of the epidemiology of VAP in Southeast Asia is essential to optimise treatments and patient outcomes. Methods: VAP epidemiology in an intensive care unit in Vietnam was investigated. A prospective cohort study was conducted. Patients who were ventilated for >48 hours, diagnosed with VAP, and had a positive respiratory culture between October 2015 and March 2017 were included. Whole-genome sequencing (WGS) was performed on Acinetobacter baumannii isolates. Results: We identified 125 patients (137 episodes) with VAP from 1,699 admissions. Twelve patients had 2 VAP episodes. The median age was 60 years (interquartile range: 48-70), and 68.8% of patients were male. Diabetes mellitus was the most frequent comorbidity (N=35, 28%). Acinetobacter baumannii was most frequently isolated in the first VAP episode (N=84, 67.2%) and was multiply resistant to meropenem, levofloxacin, and amikacin. The 30-day mortality rate was 55.2% (N=69) and higher in patients infected with A. baumannii (N=52, 65%). WGS results suggested a complex spread of multiple clones. Conclusions: In an intensive care unit in Vietnam, VAP due to A. baumannii had a high mortality rate, and A. baumannii and K. pneumoniae were multidrug resistant, with carbapenem resistance of 97% and 70%, respectively.

Boosting the ultraviolet shielding and thermal retardancy properties of unsaturated polyester resin by employing electrochemically exfoliated e-GO nanosheets.

In this work, a series of unsaturated polyester resin (UPRs)/electrochemically exfoliated graphene oxide (e-GO) polymer nanocomposites with different ratios of e-GO (0.05, 0.1, 0.15, and 0.2 wt%) were prepared via an in situ polymerization method. The surface morphology and structural and chemical properties of the original UPR and UPR/e-GO nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). The positive influence of e-GO nanosheets on the mechanical properties, thermal stability, and anti-UV aging performance of UPR/e-GO nanocomposites was demonstrated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The obtained results showed that the incorporation of e-GO nanosheets within the UPR matrix, despite the addition of e-GO at as low as 0.2 wt% comprehensively improves the advanced functional properties of UPR/e-GO nanocomposites as compared to the original UPR. In addition, artificial weathering testing of quartz-based artificial stone using UPR/e-GO 0.2 wt% showed excellent UV-resistant efficiency, supporting the use of e-GO nanosheets as an additive in manufacturing the industrial-scale UPRs-based artificial quartz stone samples for real outdoor applications.

The Vietnamese version of the Home Falls and Accidents Screening Tool (HOME FAST) - A preliminary study of validity and inter-rater reliability.

Introduction: The Vietnamese Home Falls and Accidents Screening Tool (HOME FAST) was developed to measure the number of home hazards present in the homes of older Vietnamese people and the risk of falls. Methods: The HOME FAST and the HOME FAST manual were translated into Vietnamese by an independent translator and underwent backward translation by local health professionals into English to evaluate the accuracy of the translation. A panel of 14 Vietnamese health professionals evaluated the validity of the HOME FAST translation and rated the clarity and cultural relevance of each item. Ratings were evaluated using the content validity index (CVI). Reliability in ratings of the HOME FAST was evaluated using intra-class correlations (ICC), and ratings took place within the homes of two older Vietnamese people by six assessors. Results: In all, 22 out of 25 Vietnamese HOME FAST items were considered to have met content validity standards using the CVI. The ICC for home visit one was 0.94 (95% CI 0.87-0.97) and for home visit two was ICC 0.95 (95% CI 0.91-0.98) indicating high reliability. Discussion and conclusion: Bathroom items showed the most inconsistency in ratings indicating cultural differences in bathing activities. Descriptors of HOME FAST items will be reviewed for use in Vietnam to account for cultural and environmental differences. A larger pilot study is planned with older people living in the community in Vietnam to include calendar ascertainment of falls to determine if home hazards are associated with falling.

Synaptic boutons are smaller in chandelier cell cartridges in autism.

Chandelier (Ch) cells are cortical interneurons with axon terminal structures known as cartridges that synapse on the axon initial segment of excitatory pyramidal neurons. Previous studies indicate that the number of Ch cells is decreased in autism, and that GABA receptors are decreased in the Ch cell synaptic target in the prefrontal cortex. To further identify Ch cell alterations, we examined whether the length of cartridges, and the number, density, and size of Ch cell synaptic boutons, differed in the prefrontal cortex of cases with autism versus control cases. We collected samples of postmortem human prefrontal cortex (Brodmann Area (BA) 9, 46, and 47) from 20 cases with autism and 20 age- and sex-matched control cases. Ch cells were labeled using an antibody against parvalbumin, a marker that labeles soma, cartridges, and synaptic boutons. We found no significant difference in the average length of cartridges, or in the total number or density of boutons in control subjects vs. subjects with autism. However, we found a significant decrease in the size of Ch cell boutons in those with autism. The reduced size of Ch cell boutons may result in reduced inhibitory signal transmission and impact the balance of excitation to inhibition in the prefrontal cortex in autism.

Observation of Multi-Phonon Emission in Monolayer WS2 on Various Substrates.

Transition metal dichalcogenides (TMDs) have unique absorption and emission properties that stem from their large excitonic binding energies, reduced-dielectric screening, and strong spin-orbit coupling. However, the role of substrates, phonons, and material defects in the excitonic scattering processes remains elusive. In tungsten-based TMDs, it is known that the excitons formed from electrons in the lower-energy conduction bands are dark in nature, whereas low-energy emissions in the photoluminescence spectrum have been linked to the brightening of these transitions, either via defect scattering or via phonon scattering with first-order phonon replicas. Through temperature and incident-power-dependent studies of WS2 grown by CVD or exfoliated from high-purity bulk crystal on different substrates, we demonstrate that the strong exciton-phonon coupling yields brightening of dark transitions up to sixth-order phonon replicas. We discuss the critical role of defects in the brightening pathways of dark excitons and their phonon replicas, and we elucidate that these emissions are intrinsic to the material and independent of substrate, encapsulation, growth method, and transfer approach.

Gold nanoparticle-based optical nanosensors for food and health safety monitoring: recent advances and future perspectives.

Modern society has been facing serious health-related problems including food safety, diseases and illness. Hence, it is urgent to develop analysis methods for the detection and control of food contaminants, disease biomarkers and pathogens. As the traditional instrumental methods have several disadvantages, including being time consuming, and having high cost and laborious procedures, optical nanosensors have emerged as promising alternative or complementary approaches to those traditional ones. With the advantages of simple preparation, high surface-to-volume ratio, excellent biocompatibility, and especially, unique optical properties, gold nanoparticles (AuNPs) have been demonstrated as excellent transducers for optical sensing systems. Herein, we provide an overview of the synthesis of AuNPs and their excellent optical properties that are ideal for the development of optical nanosensors based on local surface plasmon resonance (LSPR), colorimetry, fluorescence resonance energy transfer (FRET), and surface-enhanced Raman scattering (SERS) phenomena. We also review the sensing strategies and their mechanisms, as well as summarizing the recent advances in the monitoring of food contaminants, disease biomarkers and pathogens using developed AuNP-based optical nanosensors in the past seven years (2015-now). Furthermore, trends and challenges in the application of these nanosensors in the determination of those analytes are discussed to suggest possible directions for future developments.

Cerebral Microbleeds in Fragile X-Associated Tremor/Ataxia Syndrome.

BACKGROUND: Fragile X-associated tremor/ataxia syndrome is a neurodegenerative disease of late onset developed by carriers of the premutation in the fragile x mental retardation 1 (FMR1) gene. Pathological features of neurodegeneration in fragile X-associated tremor/ataxia syndrome include toxic levels of FMR1 mRNA, ubiquitin-positive intranuclear inclusions, white matter disease, iron accumulation, and a proinflammatory state. OBJECTIVE: The objective of this study was to analyze the presence of cerebral microbleeds in the brains of patients with fragile X-associated tremor/ataxia syndrome and investigate plausible causes for cerebral microbleeds in fragile X-associated tremor/ataxia syndrome. METHODS: We collected cerebral and cerebellar tissue from 15 fragile X-associated tremor/ataxia syndrome cases and 15 control cases carrying FMR1 normal alleles. We performed hematoxylin and eosin, Perls and Congo red stains, ubiquitin, and amyloid ß protein immunostaining. We quantified the number of cerebral microbleeds, amount of iron, presence of amyloid ß within the capillaries, and number of endothelial cells containing intranuclear inclusions. We evaluated the relationships between pathological findings using correlation analysis. RESULTS: We found intranuclear inclusions in the endothelial cells of capillaries and an increased number of cerebral microbleeds in the brains of those with fragile X-associated tremor/ataxia syndrome, both of which are indicators of cerebrovascular dysfunction. We also found a suggestive association between the amount of capillaries that contain amyloid ß in the cerebral cortex and the rate of disease progression. CONCLUSION: We propose microangiopathy as a pathologic feature of fragile X-associated tremor/ataxia syndrome. © 2021 International Parkinson and Movement Disorder Society.

Multivalent HER2-binding polymer conjugates facilitate rapid endocytosis and enhance intracellular drug delivery.

Incorporating targeting moieties that recognize cancer-specific cellular markers can enhance specificity of anticancer nanomedicines. The HER2 receptor is overexpressed on numerous cancers, making it an attractive target. However, unlike many receptors that trigger endocytosis upon ligand binding, HER2 is an internalization-resistant receptor. As most chemotherapeutics act on intracellular targets, this presents a significant challenge for exploiting HER2 overexpression for improved tumor killing. However, hyper-crosslinking of HER2 has been shown to override the receptor's native behavior and trigger internalization. This research co-opts this crosslinking-mediated internalization for efficient intracellular delivery of an anticancer nanomedicine - specifically a HPMA copolymer-based drug delivery system. This polymeric carrier was conjugated with a small (7 kDa) HER2-binding affibody peptide to produce a panel of polymer-affibody conjugates with valences from 2 to 10 peptides per polymer chain. The effect of valence on surface binding and uptake was evaluated separately. All conjugates demonstrated similar (nanomolar) binding affinity towards HER2-positive ovarian carcinoma cells, but higher-valence conjugates induced more rapid endocytosis, with over 90% of the surface-bound conjugate internalized within 4 h. Furthermore, this enhancement was sensitive to crowding - high surface loading reduced conjugates' ability to crosslink receptors. Collectively, this evidence strongly supports a crosslinking-mediated endocytosis mechanism. Lead candidates from this panel achieved high intracellular delivery even at picomolar treatment concentrations; untargeted HPMA copolymers required 1000-fold higher treatment concentrations to achieve similar levels of intracellular accumulation. This increased intracellular delivery also translated to a more potent nanomedicine against HER2-positive cells; incorporation of the chemotherapeutic paclitaxel into this targeted carrier enhanced cytotoxicity over untargeted polymer-drug conjugate.

Chemical Composition and Biological Activities of Metabolites from the Marine Fungi Penicillium sp. Isolated from Sediments of Co To Island, Vietnam.

Marine microorganisms are an invaluable source of novel active secondary metabolites possessing various biological activities. In this study, the extraction and isolation of the marine sediment Penicillium species collected in Vietnam yielded ten secondary metabolites, including sporogen AO-1 (1), 3-indolecarbaldehyde (2), 2-[(5-methyl-1,4-dioxan-2-yl)methoxy]ethanol (3), 2-[(2R-hydroxypropanoyl)amino]benzamide (4), 4-hydroxybenzandehyde (5), chrysogine (6), 3-acetyl-4-hydroxycinnoline (7), acid 1H-indole-3-acetic (8), cyclo (Tyr-Trp) (9), and 2',3'-dihydrosorbicillin (10). Their structures were identified by the analysis of 1D and 2D NMR data. Among the isolated compounds, 2-[(5-methyl-1,4-dioxan-2-yl)methoxy]ethanol (3) showed a strong inhibitory effect against Enterococcus faecalis with a minimum inhibitory concentration value of 32 µg/mL. Both 2-[(2R-hydroxypropanoyl)amino]benzamide (4) and 4-hydroxybenzandehyde (5) selectively inhibited E. coli with minimum inhibitory concentration values of 16 and 8 µg/mL, respectively. 2',3'-Dihydrosorbicillin (10) potentially inhibited α-glucosidase activity at a concentration of 2.0 mM (66.31%).

Author Correction: High-resolution record reveals climate-driven environmental and sedimentary changes in an active rift.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

High-resolution record reveals climate-driven environmental and sedimentary changes in an active rift.

Young rifts are shaped by combined tectonic and surface processes and climate, yet few records exist to evaluate the interplay of these processes over an extended period of early rift-basin development. Here, we present the longest and highest resolution record of sediment flux and paleoenvironmental changes when a young rift connects to the global oceans. New results from International Ocean Discovery Program (IODP) Expedition 381 in the Corinth Rift show 10s-100s of kyr cyclic variations in basin paleoenvironment as eustatic sea level fluctuated with respect to sills bounding this semi-isolated basin, and reveal substantial corresponding changes in the volume and character of sediment delivered into the rift. During interglacials, when the basin was marine, sedimentation rates were lower (excepting the Holocene), and bioturbation and organic carbon concentration higher. During glacials, the basin was isolated from the ocean, and sedimentation rates were higher (~2-7 times those in interglacials). We infer that reduced vegetation cover during glacials drove higher sediment flux from the rift flanks. These orbital-timescale changes in rate and type of basin infill will likely influence early rift sedimentary and faulting processes, potentially including syn-rift stratigraphy, sediment burial rates, and organic carbon flux and preservation on deep continental margins worldwide.

Antimicrobial susceptibility of Burkholderia pseudomallei isolates in Northern Vietnam.

OBJECTIVES: The antimicrobial susceptibility pattern of clinical Burkholderia pseudomallei (B. pseudomallei) in Vietnam has not been reported since the first publication in 2008. The present study aimed to determine the antimicrobial susceptibility pattern of B. pseudomallei isolated in a tertiary referral centre in Hanoi from January 2012 to December 2017. METHODS: A total of 312 B. pseudomallei isolates obtained from melioidosis patients admitted to a 2000-bed general hospital were analysed by the Etest method. Interpretation of the susceptibility testing results were reported using Clinical and Laboratory Standards Institute guidelines. RESULTS: All isolates were susceptible to ceftazidime, imipenem and amoxicillin-clavulanate (100%) with MIC90s relatively low (2µg/mL). Two isolates had intermediate resistance to doxycycline (0.6%) and 34 isolates were resistant to trimethoprim/sulfamethoxazole (10.9%). CONCLUSION: The results of this study suggest that currently recommended antibiotics for melioidosis treatment can be empirically used, but continuously monitoring antimicrobial susceptibility should be a concern.

Assessment of Bacteremia in a Large Tertiary Care Hospital in Northern Vietnam: a Single-Center Retrospective Surveillance Study.

The clinical analysis of cases of bacteremia is valuable. However, limited data on bacteremia are available in Vietnam. We conducted a single-center retrospective surveillance study at the Bach Mai Hospital, Hanoi, Vietnam between 2009 and 2012. In total, 45,366 blood cultures were analyzed. The number of blood cultures per 1,000 patient-days was 9.59 sets. The percentage of solitary blood culture sets was 49.6%, and the rate of positive blood cultures was 13.9%. The major pathogens isolated in adults were coagulase-negative Staphylococcus species (16.7%), followed by Escherichia coli (6.8%), Streptococcus spp. excluding Streptococcus pneumoniae (3.8%), and Staphylococcus aureus (5.2%). Other major pathogens identified were Klebsiella spp. (4.2%) and Acinetobacter spp. (2.2%). The number of blood cultures per 1,000 patient-days was lower and the percentage of solitary blood culture sets higher than that of a Japanese study (9.6 vs. 25.2 and 49.6% vs. 32.8%, respectively). The distribution of microorganisms was unique in terms of the relative predominance of cases of Acinetobacter bacteremia. The percentage of cases of healthcare-associated bacteremia may be relatively high.

Emergence of colistin-resistant Escherichia coli clinical isolates harboring mcr-1 in Vietnam.

The mcr-1 was first detected on a plasmid in colistin-resistant Escherichia coli from livestock and patients in China. We described here the emergence of colistin-resistant E. coli clinical isolates harboring mcr-1 on the chromosomes in Vietnam. To our knowledge, this is the first report of hospital-acquired E. coli isolates harboring mcr-1 in a medical setting in Vietnam.

Extreme hydrothermal conditions at an active plate-bounding fault.

Temperature and fluid pressure conditions control rock deformation and mineralization on geological faults, and hence the distribution of earthquakes. Typical intraplate continental crust has hydrostatic fluid pressure and a near-surface thermal gradient of 31 ± 15 degrees Celsius per kilometre. At temperatures above 300-450 degrees Celsius, usually found at depths greater than 10-15 kilometres, the intra-crystalline plasticity of quartz and feldspar relieves stress by aseismic creep and earthquakes are infrequent. Hydrothermal conditions control the stability of mineral phases and hence frictional-mechanical processes associated with earthquake rupture cycles, but there are few temperature and fluid pressure data from active plate-bounding faults. Here we report results from a borehole drilled into the upper part of the Alpine Fault, which is late in its cycle of stress accumulation and expected to rupture in a magnitude 8 earthquake in the coming decades. The borehole (depth 893 metres) revealed a pore fluid pressure gradient exceeding 9 ± 1 per cent above hydrostatic levels and an average geothermal gradient of 125 ± 55 degrees Celsius per kilometre within the hanging wall of the fault. These extreme hydrothermal conditions result from rapid fault movement, which transports rock and heat from depth, and topographically driven fluid movement that concentrates heat into valleys. Shear heating may occur within the fault but is not required to explain our observations. Our data and models show that highly anomalous fluid pressure and temperature gradients in the upper part of the seismogenic zone can be created by positive feedbacks between processes of fault slip, rock fracturing and alteration, and landscape development at plate-bounding faults.

Multidrug-Resistant Sequence Type 235 Pseudomonas aeruginosa Clinical Isolates Producing IMP-26 with Increased Carbapenem-Hydrolyzing Activities in Vietnam.

Forty clinical isolates of multidrug-resistant Pseudomonas aeruginosa were obtained in a medical setting in Hanoi, Vietnam. Whole genomes of all 40 isolates were sequenced by MiSeq (Illumina), and phylogenic trees were constructed from the single nucleotide polymorphism concatemers. Of these 40 isolates, 24 (60.0%) harbored metallo-ß-lactamase-encoding genes, including blaIMP-15, blaIMP-26, blaIMP-51, and/or blaNDM-1 Of these 24 isolates, 12 harbored blaIMP-26 and belonged to sequence type 235 (ST235). Escherichia coli expressing blaIMP-26 was significantly more resistant to doripenem and meropenem than E. coli expressing blaIMP-1 and blaIMP-15 IMP-26 showed higher catalytic activity against doripenem and meropenem than IMP-1 and against all carbapenems tested, including doripenem, imipenem, meropenem, and panipenem, than did IMP-15. These data suggest that clinical isolates of multidrug-resistant ST235 P. aeruginosa producing IMP-26 with increased carbapenem-hydrolyzing activities are spreading in medical settings in Vietnam.

Antimicrobial-resistant Pseudomonas aeruginosa and Acinetobacter baumannii From Patients With Hospital-acquired or Ventilator-associated Pneumonia in Vietnam.

PURPOSE: Multidrug-resistant bacterial pathogens are becoming a significant problem worldwide. Acinetobacter baumannii and Pseudomonas aeruginosa are problematic multidrug-resistant pathogens. This multicenter study in Vietnam determined the level of resistance to antimicrobial agents used to treat A baumannii and P aeruginosa infections in this country. METHODS: Five medical centers in Vietnam provided 529 P aeruginosa and 971 Acinetobacter species (904 A baumannii) isolates from patients with hospital-acquired or ventilator-associated pneumonia from 2012 to 2014. A central laboratory verified identification of the isolates and performed susceptibility testing using Clinical and Laboratory Standards Institute methods. FINDINGS: Resistance to cephalosporins, ß-lactam/ß-lactamase inhibitors, carbapenems, and fluoroquinolones was >90% against A baumannii. Aminoglycosides had only slightly better activity, with amikacin resistance >80%. Only colistin (MIC90, ≤0.25 mg/L) and tigecycline (MIC90, 4 mg/L) had appreciable activity against A baumannii. Similar activity was observed among the ß-lactams tested against P aeruginosa. Cefepime demonstrated the highest activity (60.1% susceptible), which was similar to doripenem (58.6% susceptible), the most active carbapenem tested. Amikacin was the most active aminoglycoside tested against P aeruginosa, with susceptibility of 81.7% compared with tobramycin (58.0%) and gentamicin (56.5%). Fluoroquinolones had limited activity against P aeruginosa with susceptibility to ciprofloxacin (55.0%). All P aeruginosa isolates had colistin MIC values ≤2 mg/L. IMPLICATIONS: The data from this 3-year longitudinal study in Vietnam demonstrate that 2 of the most common nonfermentative gram-negative pathogens associated with hospital-acquired and ventilator-associated pneumonia are significantly resistant to most of the available treatment options and require combination therapies unless new antimicrobial agents become available.

Antifungal susceptibility of invasive Candida bloodstream isolates from the Asia-Pacific region.

Bloodstream infections caused by Candida species are of increasing importance and associated with significant mortality. We performed a multi-centre prospective observational study to identify the species and antifungal susceptibilities of invasive bloodstream isolates of Candida species in the Asia-Pacific region. The study was carried out over a two year period, involving 13 centers from Brunei, Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam. Identification of Candida species was performed at each study center, and reconfirmed at a central laboratory. Susceptibility testing was performed using a commercial broth dilution panel (Sensititre YeastOne YST-010, Thermofisher, United Kingdom) with susceptibility categorisation (S = susceptible, S-DD = susceptible dose-dependent) applied using breakpoints from the Clinical Laboratory Standards Institute. Eight hundred and sixty-one Candida isolates were included in the study. The most common species were C. albicans (35.9%), C. tropicalis (30.7%), C. parapsilosis (15.7%), and C. glabrata (13.6%). Non-albicans species exceeded C. albicans species in centers from all countries except Taiwan. Fluconazole susceptibility was almost universal for C. albicans (S = 99.7%) but lower for C. tropicalis (S = 75.8%, S-DD = 6.1%), C. glabrata (S-DD = 94.9%), and C. parapsilosis (S = 94.8%). Echinocandins demonstrated high rates of in vitro susceptibility (S>99%) against C. albicans, C. tropicalis, and C. parapsilosis This study demonstrates that non-albicans species are the most common isolates from bloodstream infections in most countries in the Asia-Pacific region, with C. tropicalis as the predominant species. Because of the prevalence of reduced susceptibility to fluconazole in non-albicans species, the study indicates that echinocandins should be the antifungal of choice in clinically unstable or high-risk patients with documented candidemia.

IMP-51, a novel IMP-type metallo-ß-lactamase with increased doripenem- and meropenem-hydrolyzing activities, in a carbapenem-resistant Pseudomonas aeruginosa clinical isolate.

A meropenem-resistant Pseudomonas aeruginosa isolate was obtained from a patient in a medical setting in Hanoi, Vietnam. The isolate was found to have a novel IMP-type metallo-ß-lactamase, IMP-51, which differed from IMP-7 by an amino acid substitution (Ser262Gly). Escherichia coli expressing blaIMP-51 showed greater resistance to cefoxitin, meropenem, and moxalactam than E. coli expressing blaIMP-7. The amino acid residue at position 262 was located near the active site, proximal to the H263 Zn(II) ligand.

Evaluation of the Etest method for detecting colistin susceptibility of multidrug-resistant Gram-negative isolates in Vietnam.

The minimum inhibitory concentrations (MICs) of colistin for 241 multidrug-resistant (MDR) Gram-negative pathogens were determined by the Etest and by the broth microdilution method (BMD). The two methods showed essential agreements of 76% (77/102) for Acinetobacter baumannii, 90% (36/40) for Pseudomonas aeruginosa and 84% (83/99) for Enterobacteriaceae isolates, with categorical agreements of 100%, 98%, and 100%, respectively. Of the 241 isolates, none showed a very major error and one (0.4%) showed a major error. MICs ranged from 0.125 to 0.5 µg/ml for all A. baumannii and most Enterobacteriaceae isolates, and from 1 to 2 µg/ml for most P. aeruginosa isolates. Of the 40 P. aeruginosa isolates, 27 (68%) showed higher colistin MICs by the Etest than by the BMD. In contrast, 77% (78/102) of the A. baumannii and 57% (56/99) of the Enterobacteriaceae isolates showed lower colistin MICs by the Etest than by the BMD. The Etest is a reliable and easy-to-use method to measure colistin MICs of MDR Gram-negative pathogens in clinical laboratories and can be used following validation by microdilution methods.