Evaluating simulator sickness and acceptability of virtual reality prototype in pain management in hospitalized patients.

Aim: Acute and chronic noncancer pain is a common healthcare problem locally and globally, and remains under treated and poorly controlled. We created a virtual reality (VR)-based prototype with customization of content to our local population. Materials & methods: This was an open-label, single center, single-arm study to examine the safety, acceptability and tolerability of the use of VR as an adjunctive tool for pain relief in hospitalized patients. The participants rated their baseline and post-VR pain and anxiety scores. Results & conclusion: All 50 patients completed the VR sessions with good tolerability and safety. Preliminary exploration of pain reduction indicated a positive effect (for pain and anxiety visual analog scale scores; p < 0.001). We believe VR is a potentially beneficial tool for use in pain management.

Rapid and Accurate Antimicrobial Susceptibility Testing Using Label-Free Electrical Impedance-Based Microfluidic Platform.

Antimicrobial resistance has become a serious threat to the global public health. Accurate and rapid antimicrobial susceptibility testing (AST) allows evidence-based prescribing of antibiotics to improve patient care and clinical outcomes. Current culture-based AST assays are inherently limited by the doubling time of bacterial reproduction, which require at least 24 h to have a decisive result. Herein, a label-free electrical impedance-based microfluidic platform designed to expedite and streamline AST procedure for clinical practice is presented. Following a 30-min exposure of bacterial samples to antibiotics, the presented high-throughput, single-bacterium level impedance characterization platform enables a rapid 2-min AST assay. The platform facilitates accurate analysis of individual bacterial viability, as indicated by changes in electrical characteristics, thereby enabling the determination of antimicrobial resistance. Moreover, the potential clinical applicability of this platform is demonstrated by testing different E. coli strains against five antibiotics, yielding 100% categorical agreements compared to standard culture methods.

Evaluation of the microbiological efficacy of cleaning agents for tracheostomy inner cannulas.

PURPOSE: Biofilms are a significant cause of morbidity in patients with indwelling medical devices. Biofilms pose a potential risk with reusable inner cannulas by increasing the risk of infections. Effective decontamination is thus vital in decreasing bioburden. The current guidelines for cleaning inner cannulas are varied, with multiple techniques being recommended, which are not supported by strong evidence. This randomized, controlled, cross-over study attempted to enumerate the bacterial count of inner cannulas used in tracheostomy patients (n = 60) pre-and post-decontamination with detergent (A) or sterile water (B). MATERIALS AND METHODS: The patients were randomly allocated to sequence A > B or B > A in 1:1 fashion. The saline flushing of the inner cannulas was plated on trypticase soy agar with 5 % sheep blood to enumerate the bacterial count. RESULTS: The mean ratio [Log (CFU)post/Log (CFU)pre]A/[Log (CFU)post/Log (CFU)pre]B based on 53 samples was 0.918 ± 0.470, two-sided 90 % confidence interval (CI) 0.812, 1.024. The equivalence criterion was met as the mean ratio after cleaning fell within the equivalence region of 0.8 and 1.25. CONCLUSION: This study demonstrated the microbiological efficacy of both detergent and sterile water in the decontamination of inner cannulas, and that sterile water was not less effective than detergent in reducing the bacterial load for safe re-use of inner cannulas. This has the potential to promote cost savings for patients with tracheostomy, both in the hospital and the community. The study findings may also be relevant in formulating tracheostomy care policies.

Bioinspired bi-phasic 3D nanoflowers of MgO/Mg(OH)2 coated melamine sponge as a novel bactericidal agent.

By roughly mimicking the surface architectural design of dragonfly wings, novel bi-phasic 3D nanoflowers of MgO/Mg(OH)2 were successfully synthesized via the electrospinning technique. The 3D nanoflowers were coated over a commercial melamine sponge and extensively characterized by SEM, XRD, FTIR, and EDS. The formation of distinct dense 3D nano petals was revealed by SEM images whereby the mean petal thickness and mean distance between the adjacent petals were found to be 36 nm and 121 nm, respectively. The bactericidal activities of synthesized 3D nano-flowers coated melamine sponges were assessed against five different bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa). This study demonstrated significant bactericidal activity of MgO/Mg(OH)2 3D nanoflowers coated MS against Gram-positive and Gram-negative bacteria. Plausible bactericidal mechanisms include envelope deformation, penetration, and induction of oxidative stress. This study introduces novel bioinspired biomaterial with the capacity to reduce the risk associated with pathogenic bacterial infections, especially in medical devices.

Clinical trial: seven-day vonoprazan- versus 14-day proton pump inhibitor-based triple therapy for first-line Helicobacter pylori eradication.

BACKGROUND: One-week triple therapy with vonoprazan is endorsed by Japanese guidelines as an alternative to proton pump inhibitor (PPI)-based triple therapy for first-line Helicobacter pylori eradication. This contrasts with Western guidelines recommending 2-week PPI-based triple therapy. AIM: To verify the non-inferiority of 1-week vonoprazan-based triple therapy versus 2-week PPI-based triple therapy as first-line H. pylori eradication in a multiracial Asian cohort. METHODS: Randomised controlled trial of treatment-naïve patients with H. pylori infection assigned 1:1 to either 7 days amoxicillin 1 g + clarithromycin 500 mg + vonoprazan 20 mg twice per day or 14 days amoxicillin 1 g + clarithromycin 500 mg + omeprazole OR esomeprazole OR rabeprazole 20 mg twice/day. Subjects were randomly assigned to each PPI 1:1:1 Demographics, H. pylori resistance, CYP 2C19 genotype, eradication success and safety profiles were compared between groups. RESULTS: Between June 2019 and June 2021, 252 of 1097 subjects screened were randomised. 244 (age [SD] 51.7 [14.6]) received vonoprazan- (n = 119) or PPI-based (n = 125) triple therapy. Eradication rates by intention-to-treat analysis were 87.4% (vonoprazan-based triple therapy) versus 88.0% (PPI-based triple therapy. By per protocol analysis: 96.3% (vonoprazan-based triple therapy) versus 94.0% (PPI-based triple therapy). Clarithromycin resistance predicted treatment failure on multivariate analysis: RR 11.4; 95% CI [1.4-96.3], p = 0.025. No significant differences in CYP 2C19 genotypes or adverse events occurred between groups. CONCLUSION: One-week vonoprazan-based triple therapy achieved comparable efficacy to 2-week PPI-based triple therapy and was well tolerated.

Evaluation of the clinical sensitivity and specificity of the BD Max™ Enteric Bacterial Panel for molecular detection of pathogens for acute gastroenteritis in the Singaporean population.

PURPOSE: Acute gastroenteritis (AGE) is caused by a wide range of pathogens. Culture methods for the detection of bacterial pathogens is time consuming and labour intensive. This study compared a same-day-to-result commercial molecular method using BD Max™ Enteric Bacterial Panel against conventional culture and laboratory-developed PCR assays (LDTs), and characterised the epidemiology of bacterial AGE in Singapore. METHODOLOGY: PCRs for Campylobacter spp., Salmonella spp., Shigella spp./Enteroinvasive Escherichia coli (EIEC) and Shiga toxin-producing E. coli (STEC)/Shigella dysenteriae were performed on the BD Max™ platform. Concurrent routine bacterial culture ("reference standard") was performed for Campylobacter, Salmonella, Shigella, Vibrio and Aeromonas spp. In the event of a discrepancy, an "expanded reference standard" (bacterial culture with LDT) was used. RESULTS: There were 299 stool specimens in the study, with no bacterial pathogens detected in 190 samples (63.5%). The positive samples (n = 109,36.5%) were detected with Salmonella (n = 57,19.1%), Campylobacter (n = 28,9.4%), Vibrio parahaemolyticus (n = 6,2.0%), Shigella/EIEC (n = 6,2.0%), ETEC (n = 4,1.3%), STEC (n = 2,0.7%), Aeromonas (n = 2,0.7%), Plesiomonas shigelloides (n = 1,0.3%) and 3(1.0%) co-infections. Compared to the "expanded reference standard", conventional culture missed 38/112 (33.9%) pathogens. Conversely, testing by BD Max™ alone failed to detect 17 pathogens. BD Max™ reported seven (2.3%) false-positive results. CONCLUSIONS: BD Max™ increased the detection rate of bacterial AGE pathogens in the panel, but was limited by the absence of detection capability for Vibrio and Aeromonas spp.

Evaluation of a six-probe cocktail (caffeine, tolbutamide, omeprazole, dextromethorphan, midazolam, and digoxin) approach to estimate hepatic drug detoxification capability and dosage requirements after a single oral dosing in healthy Chinese volunteers.

The primary objectives of this study were to investigate the suitability of a 6-probe cocktail (caffeine, tolbutamide, omeprazole, dextromethorphan, midazolam, and digoxin) to be used as a tool for assessing the activity of drug metabolizing enzymes and transporters, and examine differences in the way drugs are handled among groups with different genetic regulation of these processes. This was a single-center, open-label, phase I clinical study involving 20 young, healthy Chinese volunteers (equal gender distribution). The subjects were administered a single, oral dose of the 6-probe cocktail and serum samples were collected to assess the disposition of the different probe substrates and produced metabolites. The serum samples were analyzed using ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry technology. The DNA samples were subjected to whole exome sequencing. Nineteen healthy volunteers completed the study. The 6-probe cocktail was safe and well-tolerated by all the subjects. The parent substrates and metabolites-caffeine (paraxanthine), dextromethorphan (dextrorphan), digoxin, midazolam (1-hydroxy-midazolam), omeprazole (5-hydroxy-omeprazole), and tolbutamide (4-hydroxy-tolbutamide)-were within the detectable window. Genetic variations known to alter drug metabolism (CYP2D6*10, CYP2C19*2, CYP2C19*3, and CYP2C9*3) were identified and generally correlated with phenotypic status. The 6-probe cocktail appeared to be suitable for assessing drug metabolizing activities. This, in conjunction with individual genetics, will pave the way for the implementation of personalized medicine in clinical practice. This will hopefully improve efficacy and reduce the incidence of adverse drug reactions.

A device to detect leakage at the patient end of total intravenous anaesthesia.

The use of total intravenous anaesthesia (TIVA) is limited by concerns of disconnections of the tubing, resulting in accidental awareness. We designed a sensor device to detect leakages at the patient end and notify the medical personnel, thereby allowing immediate intervention in preventing awareness. For moisture detection, resistive sensing was selected as the working principle. The prototype was in proximity to the tubing from the TIVA pump and the patient's intravenous cannula, and able to detect leakages in all potential leakage sites and activate an alarm. Our device consists of a disposable bandage (sensor), attached to a reusable clamp that is directly coupled to a central module (SparkFun MicroView, a small microcontroller with built-in Organic Light-Emitting Diode (OLED) display). The disposable bandage is wrapped around the possible leakage sites. Crucially, the disposable bandage is integrated with two separate moisture sensing threads. When moisture is present, the central module detects a drop in resistance across the moisture sensing threads and activates a flashing LED and buzzer. We have successfully created a functional leak detection device, comprising a moisture sensing bandage and an audio and visual alert system, to address the problem of undetected TIVA leakages at the patient end.

A Study of Analytical and Clinical Sensitivity of Aptima SARS-CoV-2 Assay (Hologic) and Proposals of Complementary Tests for SARS-CoV-2 Detection in Low Viral Load Specimens.

Early and accurate detection of SARS-CoV-2 is important for diagnosis and transmission control. The use of high-throughput and automated testing allows laboratories to better deliver diagnostic testing given manpower and resource limitations. We validated the clinical and analytical performance of the Hologic Panther Aptima SARS-CoV-2 assay with an emphasis on detection of specimens with low viral loads. The clinical performance was evaluated using 245 clinical specimens, against a comparator PCR-based laboratory developed test (LDT). The analytical performance was determined by replicate testing of contrived samples in a ten-fold dilution series (CT values 32-42, based on LDT). The Aptima assay had 96.7% overall percent agreement, 100% negative percent agreement and 88.1% positive percent agreement. It was able to consistently detect SARS-CoV-2 in contrived samples with CT = 32 by LDT (calculated 2354 copies/mL). The 95% limit of detection of the Aptima assay was estimated to be at LDT CT = 33 (equivalent to 870 copies/mL). The relative light units (RLU) × 1000 for 52 true positive clinical specimens was 962.2 ± 181.5, and that for the 186 true negative specimens was 264.6 ± 14.3. The Aptima assay was a reliable method with a high overall percent agreement against our comparator LDT. We propose that samples reported as negative by the Aptima assay with RLU > 350 be tested by a secondary method, in order to improve detection of samples with very low viral loads.

Development of a rapid multiplex PCR assay for the detection of common pathogens associated with community-acquired pneumonia.

BACKGROUND: Community-acquired pneumonia (CAP) is one of the most common infectious diseases and is a significant cause of mortality and morbidity globally. A microbial cause was not determined in a sizable percentage of patients with CAP; there are increasing data to suggest regional differences in bacterial aetiology. We devised a multiplex real-time PCR assay for detecting four microorganisms (Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae and Burkholderia pseudomallei) of relevance to CAP infections in Asia. METHODS: Analytical validation was accomplished using bacterial isolates (n=10-33 of each target organism for analytical sensitivity and n=117 for analytical sensitivity) and clinical validation using 58 culture-positive respiratory tract specimens. RESULTS: The qPCR assay exhibited 100% analytical sensitivity and analytical specificity, and 100% clinical sensitivity and 94-100% clinical specificity. The limit of detection and efficiency for the multiplex PCR assay were 3-33 CFU/mL and 93-110%, respectively. The results showed that the PCR-based method had higher sensitivity than traditional culture-based methods. The assay also demonstrated an ability to semiquantify bacterial loads. CONCLUSION: We have devised a reliable laboratory-developed multiplex qPCR assay, with a turnaround time of within one working day, for detection of four clinically important CAP-associated microorganisms in Asia. The availability of a test with improved diagnostic capabilities potentially leads to an informed choice of antibiotic usage and appropriate management of the patient to achieve a better treatment outcome and financial savings.

Sheathless and high-throughput elasto-inertial bacterial sorting for enhancing molecular diagnosis of bloodstream infection.

Purification of bacteria from human blood samples is essential for rapid identification of pathogens by molecular methods, enabling faster and more accurate diagnosis of bloodstream infection than conventional gold standard blood culture methods. The inertial microfluidic method has been broadly studied to isolate biological cells of interest in various biomedical applications due to its label-free and high-throughput advantages. However, because of the bacteria's tininess, which ranges from 0.5 µm to 3 µm, they are challenging to be effectively focused and sorted out in existing inertial microfluidic devices that work well with biological cells larger than 10 µm. Efforts have been made to sort bacterial cells by utilizing extremely small channel dimensions or employing a sheath flow, which thus results in limitations on the throughput and ease of operation. To overcome this challenge, we develop a method that integrates a non-Newtonian fluid with a novel channel design to allow bacteria to be successfully sorted from larger blood cells in a channel dimension of 120 µm × 20 µm without the use of sheath flows. The throughput of this device with four parallel channels is above 400 µL per minute. The real-time polymerase chain reaction (qPCR) analysis indicates that our inertial sorting approach has a nearly 3-fold improvement in pathogen recovery compared with the commonly used lysis-centrifugation method at pathogen abundances as low as 102 cfu mL-1. With the rapid and simple purification and enrichment of bacterial pathogens, the present inertial sorting method exhibits an ability to enhance the fast and accurate molecular diagnosis of bloodstream bacterial infection.

A randomized controlled trial to compare the interface pressures of alternating pressure overlay with gel pad versus gel pad alone during prolonged surgery.

INTRODUCTION: Prolonged surgery is a known risk of pressure ulcer formation. Pressure ulcers affect the quality of life, are a significant cause of morbidity and mortality, and pose a burden on the healthcare system. This study aimed to compare the effectiveness of an alternating pressure (AP) overlay with Gel pad against the Gel pad in reducing interface pressure (IP) during prolonged surgery. METHODS: A total of 180 participants from a tertiary hospital were randomized to AP overlay with Gel pad group (n = 90) and Gel pad group (n = 90). Patients were placed supine on the pressure redistributing surfaces, and IP data under the sacrum and ischial tuberosities were collected at an interval of 30 min from 0 min up to a maximum of 570 min. RESULTS: Based on data from 133 participants, the average IPs during all the deflation cycles of the AP overlay (with Gel pad) were significantly lower than the average continuous IP recorded for Gel pad throughout the measuring period (p < 0.001). Only three patients (2.26% of study participants) - Gel pad group (n = 2; 2.99%) and AP overlay with Gel pad group (n = 1; 1.52%) developed post-operative pressure ulcer (p = 0.5687). CONCLUSIONS: The lower IP during deflation cycles of the AP overlay (with Gel pad) suggests its potential effectiveness in preventing pressure ulcer formation in patients undergoing prolonged surgery. The prevention and reduction of pressure ulcers will have a considerable impact on the improved quality of life and cost savings for the patient. The study findings may facilitate the formulation of policies for preventing pressure ulcer development in the perioperative setting.

Experiential learning in simulated parapharyngeal abscess in breathing cadavers.

PURPOSE: Education in airway management is a fundamental component of anesthesiology training programs. There has been a shift towards the use of simulation models of higher fidelity for education in airway management. The goal of this study was to create a novel cadaveric model of a simulated parapharyngeal abscess with features of a difficult airway such as distorted anatomy and narrow airway passages presenting as stridor. The model was further assessed for its suitability for enhanced experiential learning in the management of difficult airways. METHODS: Cadaver heads were modified surgically to simulate parapharyngeal abscess. Airtight torso of the cadaver was connected to an Oxylog ventilator to simulate respiratory movements-the opening and closing of air channels with breaths in a patient with parapharyngeal abscess. Advanced airway workshop facilitators conducted directed one-to-one learning, and provided feedback to participants. A paper-based feedback was obtained from 72 participants on their confidence level, and the realism, attractiveness, beneficial, and difficulty levels of the simulated cadaveric models. RESULTS: The modified cadavers were reliable in simulating difficult airways. The majority of participants (91%) reported an increase in confidence level for management of the difficult airway after the experience with the modified cadavers and found the models realistic (93%), attractive (92%), beneficial (93%), and difficult (85%). CONCLUSIONS: Surgical modifications of cadavers to simulate difficult airways such as parapharyngeal abscess with edema and stridor can be incorporated into advanced airway management courses to enhance experiential learning in airway management by awake fibreoptic intubation, and promote patient safety.

Enhanced Experiential Learning in Airway Management: Surgical Modification of Cadavers.

INTRODUCTION: Failure of airway management remains a significant source of morbidity and mortality. Advanced airway management has been addressed effectively by simulation-based training. However, simulation of difficult airways in manikins is limited by the pre-set conditions provided by the manufacturer. Life-like conditions in the form of the softness of the tissue and true anatomy as seen in cadaver models are needed to create simulated models with a closer resemblance to real patients. The goal of this study was to determine the feasibility of simulating difficult airway from submandibular abscess in cadaver models by surgical modification of the cadaver heads for use in enhanced experiential learning of the management of difficult airways. METHODS: The cadaver heads were modified surgically to simulate a submandibular abscess. The models were used in an airway course where participants provided feedback on the realistic nature of the model and its benefits for difficult airway training. The ease of tracheal intubation of the models with the assistance of video laryngoscopy was assessed. RESULTS: The modified cadavers were acceptable in simulating difficult airway as demonstrated by the feedback from the participants. All participants (100% [95% confidence interval = 89.1%-100%]) found the models to be realistic and beneficial for difficult airway training. A good proportion (56.3%) felt that the intubation technique was made easier with the video laryngoscopy. CONCLUSIONS: Cadavers can be modified to simulate pathologies associated with difficult airways. These models can be used to enhance experiential learning and the management of difficult airways.

Enhanced Molecular Diagnosis of Bloodstream Candida Infection with Size-Based Inertial Sorting at Submicron Resolution.

Inertial microfluidics has been proven to be a powerful tool for high-throughput, size-based cell sorting in diverse biomedical applications. In the case of Candida-related sepsis, Candida species and major blood cells (i.e., red blood cells and white blood cells) have a size distribution of 3-5 and 6-30 µm, respectively. To effectively retrieve a majority of Candida species and remove most of the interfering blood cells for accurate molecular analysis, inertial sorting of micron-sized biological particles with submicron size difference is highly desired, but far unexplored till now. In this work, we present a new channel design for an inertial microfluidic sorting device by embedding microsquares to construct periodic contractions along a series of repeating curved units. This unique channel design allows us to enhance inertial lift force at the microsquare zone and produce localized secondary Dean flow drag force in addition to global Dean flow drag force. This inertial sorting device has successfully separated 5.5 µm particles from 6.0 µm particles with a recovery ratio higher than 80% and a purity higher than 92%, demonstrating a size-based inertial sorting at submicron resolution (i.e., 0.5 µm). We further applied this inertial sorting device to purify Candida species from whole blood sample for enhanced molecular diagnosis of bloodstream Candida infection and especially compared it with the commonly used lysis-centrifugation-based purification method (STEM method) by recovering two species of Candida (Cornus glabrata and Candida albicans) from Candida-spiked blood samples. Through quantitative polymerase chain reaction (qPCR) analysis, we found that our inertial sorting approach has nearly 3-fold improvement on the pathogen recovery than the STEM method at pathogen abundances of 103 cfu/mL and 102 cfu/mL. The present inertial sorting at submicron resolution provides a simple, rapid, and efficient pathogen purification method for significantly improved molecular diagnosis of bloodstream Candida infection.

A pilot study to examine the association between human gut microbiota and the host's central obesity.

BACKGROUND AND AIM: Perturbance in the composition of human gut microbiota has been associated with metabolic disorders such as obesity, diabetes mellitus, and insulin resistance. The objectives of this study are to examine the effects of ethnicity, central obesity, and recorded dietary components on potentially influencing the human gut microbiome. We hypothesize that these factors have an influence on the composition of the gut microbiome. METHODS: Subjects of Chinese (n = 14), Malay (n = 10), and Indian (n = 11) ancestry, with a median age of 39 years (range: 22-70 years old), provided stool samples for gut microbiome profiling using 16S rRNA sequencing and completed a dietary questionnaire. The serum samples were assayed for a panel of biomarkers (interleukin-6, tumor necrosis factor alpha, adiponectin, cleaved cytokeratin 18, lipopolysaccharide-binding protein, and limulus amebocyte lysate). Central obesity was defined by waist circumference cut-off values for Asians. RESULTS: There were no significant differences in Shannon alpha diversity for ethnicity and central obesity and no associations between levels of inflammatory cytokines and obesity. The relative abundances of Anaerofilum (P = 0.02), Gemellaceae (P = 0.02), Streptococcaceae (P = 0.03), and Rikenellaceae (P = 0.04) were significantly lower in the obese group. From principle coordinate analysis, the effects of the intake of fiber and fat/saturated fat were in contrast with each other, with clustering of obese individuals leaning toward fiber. CONCLUSION: The study demonstrated that there were differences in the gut microbiome in obese individuals. Certain bacterial taxa were present in lower abundance in the group with central obesity. Fiber and fat/saturated fat diets were not the key determinants of central obesity.

Development and validation of a real-time multiplex PCR assay for the detection of dermatophytes and Fusarium spp.

Introduction: Onychomycosis is a debilitating, difficult-to-treat nail fungal infection with increasing prevalence worldwide. The main etiological agents are dermatophytes, which are common causative pathogens in superficial fungal mycoses. Conventional detection methods such as fungal culture have low sensitivity and specificity and are time-consuming.Aim: The main objective of this study was to design, develop and validate a real-time probe-based multiplex qPCR assay for the detection of dermatophytes and Fusarium species.Methodology: The performance characteristics of the qPCR assays were evaluated. The multiplex qPCR assays targeted four genes (assay 1: pan-dermatophytes/Fusarium spp.; assay 2: Trichophyton rubrum/Microsporum spp.). Analytical validation was accomplished using 150 fungal isolates and clinical validation was done on 204 nail specimens. The performance parameters were compared against the gold standard (fungal culture) and expanded gold standard (culture in conjunction with sequencing).Results: Both the single-plex and multiplex qPCR assays performed well especially when compared against the expanded gold standard. Among the 204 tested nail specimens, the culture method showed that 125 (61.3 %) were infected with at least one organism, of which 40 yielded positive results for dermatophytes and Fusarium spp. These target organisms detected include 20 dermatophytes and 22 Fusarium spp. The developed qPCR assays demonstrated excellent limit of detection, efficiency, coefficient of determination, analytical and clinical sensitivity and specificity.Conclusion: The multiplex qPCR assays were reliable for the diagnosis of onychomycosis, with shorter turn-around time as compared to culture method. This aids in the planning of treatment strategies to achieve optimal therapeutic outcome.

Interaction between Antibiotic Resistance, Resistance Genes, and Treatment Response for Urinary Tract Infections in Primary Care.

Given increasing antimicrobial resistance, we aimed to determine antibiotic susceptibility and presence of resistance genes in uropathogens in primary care, factors associated with resistance to commonly prescribed antibiotics, and effect of treatment on early symptom resolution. We conducted a prospective study of primary care patients with urinary tract infection (UTI) symptoms and culture-confirmed UTI in Singapore from 2015 to 2016. Cohort characteristics and antimicrobial susceptibility of cultured isolates were analyzed. Among Enterobacteriaceae isolates, early symptom resolution (within 3 days) according to antibiotic prescribed and isolate susceptibility and factors associated with antibiotic resistance were evaluated. Of 695 symptomatic patients, 299 were urine culture positive; of these 299 patients, 259 (87%) were female. Escherichia coli was the most common uropathogen (76%). Enterobacteriaceae isolates (n = 283) were highly susceptible to amoxicillin-clavulanate (86%), nitrofurantoin (87%), and fosfomycin (98%), but >20% were resistant to ciprofloxacin and co-trimoxazole. Isolates resistant to appropriate indicator antibiotics were further tested to determine proportions positive for blaCTX-M (14/26, 54%), plasmid-mediated ampC (12/24, 50%), qnr (7/69, 10%), and fos (1/6, 17%) resistance genes. A total of 67% of patients given antibiotics with susceptible isolates reported early resolution versus 45% given antibiotics with nonsusceptible isolates (P = 0.001) and 27% not treated (P = 0.018). On multivariable analysis, Indian ethnicity and diabetes mellitus were associated with amoxicillin-clavulanate resistance. Genitourinary abnormalities, UTI in the past 12 months, and hospitalization in the past 6 months were associated with ciprofloxacin and co-trimoxazole resistance. Patients given active empirical antibiotics were most likely to report early symptom resolution, but correlation with in vitro susceptibility was imperfect. Factors associated with resistance may guide the decision to obtain initial urine culture.

Prevalence and antibiotic susceptibility of colistin-resistance gene (mcr-1) positive Enterobacteriaceae in stool specimens of patients attending a tertiary care hospital in Singapore.

OBJECTIVES: The aim of this study was to determine the prevalence of the colistin-resistance gene (mcr-1) and the antibiotic-susceptibility profile of mcr-1 positive, colistin-resistant isolates in stool specimens of patients attending a tertiary care hospital in Singapore. METHODS: 201 diarrheal stool specimens of patients attending the Changi General Hospital between May to August 2017 were collected and screened for the presence of mcr-1 by culture and molecular methods. Antibiotic-susceptibility profile of mcr-1 positive isolates was determined using the polymyxin B and colistin E-tests and the VITEK 2 system. RESULTS: We observed an unexpectedly high prevalence of mcr-1 in patients attending a tertiary care hospital in Singapore, i.e 6.0% and 8.0% estimated by stool culture and direct stool PCR, respectively. The mcr-1 gene was detected predominantly in Escherichia coli. Antibiotic-susceptibility testing on 12 mcr-1 positive Enterobacteriaceae isolates revealed variable susceptibility profiles with no detection of carbapenem-resistant Enterobacteriaceae. CONCLUSIONS: This is the first report of the prevalence of human faecal carriage of mcr-1 in Singapore. Our findings highlight the potential risk of mcr-1 spread among our patient cohort. The mcr-1 gene detection combined with the detection of other resistance gene targets of clinical importance is recommended to pre-empt the spread mcr-1 in our patients.