Structural elucidation, mechanism of action, antibacterial proficiency and synergistic forte of purified Euphorbia hirta whole plant extract against multi-drug resistant otitis media infection

This study investigated the antibacterial potential of Euphorbia hirta whole plant extracts, honey and conventional antibiotics and their synergistic effects against selected multidrug resistant and typed bacterial strains associated with otitis media. E. hirta whole plant extract was purified using column chromatography technique. The antibacterial assays of extracts were done using standard microbiological procedures. Protein, sodium and potassium ion leakage of the synergistic mixtures was determined using flame-photometry. At 100 mg/ml, acetone extracts presented highest inhibition against S. aureus (NCTC 6571) with 32 ± 0.83 mm zone of inhibition. The fractional inhibitory concentration indices displayed higher synergism in combination of plant extract, honey and ciprofloxacin against P. mirabilis at 0.02 compared to drug combination synergy standard (≤ 0.5). This work revealed augmentation of ciprofloxacin potency when combined with purified E. hirta acetone extract and honey and implies their high potential in the treatment of multidrug resistant infection of otitis media.

631. Economic Analysis of Imipenem/Cilastatin/Relebactam Compared to Piperacillin/Tazobactam for Treating Hospital-Acquired and Ventilator-Associated Bacterial Pneumonia

Background Hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) is associated with high rates of morbidity and mortality; this is often worse among patients who experience a delay in receiving appropriate therapy. Initial treatment choice and early adjustment occurs prior to pathogen susceptibility results and may be based on suspicion of a resistant infection and/or clinical deterioration. This study assesses the cost effectiveness of Imipenem/cilastatin/relebactam (IMI/REL) in an early adjustment prescribing scenario compared to PIP/TAZ for patients with high risk of resistant infection from a US perspective. Methods Although early adjustment data was not directly available, pathogen susceptibility data derived from 2017-19 Study for Monitoring Antimicrobial Resistance Trends (SMART) surveillance program was applied to estimate patients who may have clinical worsening, likely due to a resistant infection. The efficacy and safety data for IMI/REL and PIP/TAZ were informed by the modified intent-to-treat population of a phase III trial (RESTORE-IMI 2). Our analysis comprised a decision tree (reflecting hospitalization period) followed by a yearly Markov model (capturing lifetime impact). The decision tree captured short-term outcomes (clinical cure, all-cause mortality, and hospital resource use). The Markov model translated short term outcomes into quality-adjusted life years (QALYs). Results were expressed as an incremental cost-effectiveness ratio (ICER). Sensitivity analyses were conducted to test the robustness of model results. Results Compared with PIP/TAZ, IMI/REL in the early adjustment setting was associated with increased costs (&10,087 per patient) but a higher cure (+7%) and lower mortality (-3%) rate. The resulting ICER (&12,173/QALY) falls well below typical US willingness to pay thresholds. Model drivers were the SMART-based susceptibility profiles and RESTORE-IMI 2 response and mortality rates. Conclusion Our results suggest that IMI/REL, used as an early adjustment option, could be considered cost effective for patients with worsening HABP/VABP in a US setting, when compared against PIP/TAZ. Disclosures Jaesh Naik, MSc, BresMed Health Solutions (Employee) Lewis Ralph, MSc, Bresmed (Employee) Ryan J. Dillon, MSc, Merck & Co. Inc., (Employee, Shareholder) Joe Yang, Ph.D., Merck & Co (Employee)

Emergence of Letermovir-resistant HCMV UL56 mutant during rescue treatment in a liver transplant recipient with ganciclovir-resistant infection HCMV: a case report

Background Human Cytomegalovirus (HCMV) still represents a crucial concern in solid organ transplant recipients (SOTRs) and the use of antiviral therapy are limited by side effects and the selection of viral mutations conferring antiviral drug resistance. Case presentation Here we reported the case of an HCMV seronegative patient with common variable immunodeficiency (CVID), multiple hepatic adenomatosis, hepatopulmonary syndrome and portal hypertension who received a liver transplant from an HCMV seropositive donor. The patient was treated with Valganciclovir (vGCV) and then IV Ganciclovir (GCV) at 5 week post-transplant for uncontrolled HCMV DNAemia. However, since mutation A594V in UL97 gene conferring resistance to ganciclovir was reported, GCV therapy was interrupted. Due to the high toxicity of Foscarnet (FOS) and Cidofovir (CDV), Letermovir (LMV) monotherapy at the dosage of 480 mg per day was administered, with a gradual viral load reduction. However, a relapse of HCMV DNAemia revealed the presence of mutation C325Y in HCMV UL56 gene conferring resistance to LMV. Conclusions In conclusion, even if LMV is an effective and favorable safety molecule it might have a lower genetic barrier to resistance. A warning on the use of LMV monotherapy as rescue treatments for HCMV GCV-resistant infections in transplant recipients is warranted.

Rescue Therapy with Furazolidone in Patients with at Least Five Eradication Treatment Failures and Multi-Resistant H. pylori infection

Helicobacter pylori infection may persist after multiple eradication treatments. The aim of this study was to evaluate the efficacy and safety of a furazolidone-based rescue regimen in hyper-refractory patients. A unicentre, prospective study was designed. Patients in whom five or more treatments had consecutively failed were included. All patients had previously received bismuth and key antibiotics, such as amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifabutin, and had positive H. pylori culture, demonstrating resistance to clarithromycin, metronidazole, and levofloxacin. A quadruple regimen with furazolidone (200 mg), amoxicillin (1 g), bismuth (240 mg), and esomeprazole (40 mg) was prescribed twice a day for 14 days. Eradication was confirmed by the stool antigen test. Compliance was determined through questioning, and adverse effects using a questionnaire. Eight patients (mean age 56 years, 63% men, 38% peptic ulcer disease, 12% gastric cancer precursor lesions, and 50% functional dyspepsia) were included. Per-protocol and intention-to-treat eradication rates were 63%. Compliance was 100%. Adverse effects were reported in two (25%) patients, and all were mild. Even after five or more previous H. pylori eradication failures, and a multi-resistant infection, rescue treatment with furazolidone may be effective in approximately two-thirds of the cases, constituting a valid strategy after multiple previous eradication failures with key antibiotics such as clarithromycin, metronidazole, tetracycline, levofloxacin, and rifabutin.

Where to from here? Identifying and prioritising future directions for addressing drug-resistant infection in Australia

Background The Australian National Antimicrobial Resistance Strategy calls for a collaborative effort to change practices that have contributed to the development of drug-resistance and for implementation of new initiatives to reduce antibiotic use. Methods A facilitated workshop was undertaken at the 2019 National Australian Antimicrobial Resistance Forum to explore the complexity of antimicrobial stewardship (AMS) implementation in Australia and prioritise future action. Participants engaged in rotating rounds of discussion using a world café format addressing six topics relating to AMS implementation. Once all tables had discussed all themes the discussion concluded and notes were summarised. The documents were independently openly coded by two researchers to identify elements relating to the implementation of antimicrobial stewardship. Results There were 39 participants in the facilitated discussions, including pharmacists, infectious disease physicians, infection prevention nurses, and others. Participants discussed strategies they had found successful, including having a regular presence in clinical areas, adapting messaging and implementation strategies for different disciplines, maintaining positivity, and being patient-focused. Many of the recommendations for the next step involved being patient focussed and outcomesdriven. This involves linking data to practice, using patient stories, using data to celebrate wins and creating incentives. Discussion Recommendations from the workshop should be included in priority setting for the implementation of AMS initiatives across Australia.

Development of an ELAA kit to detect neomycin in milk

Antibiotics used in livestock production offer various benefits as an antimicrobial agent, growth promoter, and feed effective improvement. However, the abuse of antibiotics leads to antibiotic resistance which may seriously threaten human and animal welfare, and growing levels of antibiotics or antibiotic-resistant bacteria in the environment increase the numbers of drug-resistant infection outbreaks. Therefore, many detection methods have been being developed to quickly assess antibiotic content and its residues in foods. Among many analytical methods, the aptamer-based biosensor has considerable attention for its outstanding advantages such as high specificity, high sensitivity, and good selectivity. We use the ELAA (Enzyme-Linked Aptamer Assay) method - a variant of ELISA - which has a high affinity with neomycin. Firstly, we investigated different buffers to create the Neo-BSA complex. As result, 2-(N-morpholino) ethanesulfonic acid (MES) buffer pH 7 was found with the best results. Next, to help the Neo-BSA complex be fixed well on polystyrene wells, we surveyed various buffers and found the coating buffer (50mM Bicarbonate buffer, pH 9.6) rated as the most suitable for this process. In addition, the quality of the kit is also assessed through competitive ELAA reaction components. Therefore, we have investigated and optimized conditions such as aptamer concentration 25 nM in PBS buffer, and the biotinized aptamers did not need heat treatment prior to joining the reaction. From the results, we have successfully developed a calibration curve for antibiotic residue in milk using the ELAA technique, linear range 0,1 ng/mL and 100 ng/mL. Then, we initially surveyed 20 milk samples found that the ELAA method was consistent with the results from LC-MS/MS was obtained showing no difference between the two methods. We continued to test the samples to determine the kit’s sensitivity and specificity. The results showed that the kit has a specificity and sensitivity of 100%. Finally, LOD and LOQ value had xavg = 0.448; SD = 0.22, LOD = xavg + 3SD = 1.11 (ng / ml); LOQ = x tb + 10SD = 2.65 (ng / mL). We will continue to optimize the kit before being brought to the market.

Beat Bad Microbes

Health-related information design has made a difference to people’s lives through clear explanation of procedures, processes, disease prevention and maintenance. This paper provides an example of user-centered design being applied to engage people with the prevention of drug-resistant infection. In particular, we focus on antibiotic resistance in the specific location of a community pharmacy in Rwanda. We describe an information campaign, Beat Bad Microbes, and summarize the challenges and opportunities of working in Rwanda on a cross-disciplinary project in which design research and practice are closely integrated.

Incidence of Antibiotic Treatment Failure in Patients with Nursing Home-Acquired Pneumonia and Community Acquired Pneumonia

Purpose: Nursing home-acquired pneumonia (NHAP) patients are at higher risk of multi-drug resistant infection (MDR) than those with community-acquired pneumonia (CAP). Recent evidence suggests a single risk factor for MDR does not accurately predict the need for broad-spectrum antibiotics. The goal of this study was to compare the rate antibiotic failure between NHAP and CAP patients. Methods: Demographic characteristics, co-morbidities, clinical and laboratory variables, antibiotic therapy, and mortality data were collected retrospectively for all patients with pneumonia admitted to an Internal Medicine Service between April 2017 and April 2018. Results: In total, 313 of 556 patients had CAP and 243 had NHAP. NHAP patients were older, and were more likely to be dependent, to have recent antibiotic use, and to experience treatment failure (odds ratio (OR) 1.583; 95% CI 1.102–2.276; p = 0.013). In multivariate analysis, patient’s origin did not predict treatment failure (OR 1.083; 95% CI 0.726–1.616; p = 0.696). Discussion: Higher rates of antibiotic failure and mortality in NHAP patients were explained by the presence of other risk factors such as comorbidities, more severe presentation, and age. Admission from a nursing home is not a sufficient condition to start broader-spectrum antibiotics.