Search

Treatment of cytomegalovirus (CMV) infection in allogeneic hematopoietic stem cell transplantation (alloHCT) patients with ganciclovir is complicated by toxicity and resistance. This study aimed to develop an intravenous ganciclovir population pharmacokinetic model for post-alloHCT patients and to determine dosing regimens likely to achieve suggested therapeutic exposure targets. We performed a prospective observational single-center pharmacokinetic study in adult alloHCT patients requiring treatment with intravenous ganciclovir for CMV viremia or disease. Samples were analyzed using a validated ultraperformance liquid chromatography method. Population pharmacokinetic analysis and Monte Carlo simulations (n = 1000) were performed using Pmetrics for R. Twenty patients aged 18 to 69 years were included in the study. A 2-compartment model with linear elimination from the central compartment and between occasion variability best described the data. Incorporating creatinine clearance (CLCR) estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and presence of continuous renal replacement therapy as covariates for ganciclovir clearance improved the model. Compared to current dosing recommendations, simulations demonstrated loading doses were required to achieve a target AUC24 of 80 to 120 mg.h/L on day 1 of induction therapy. Increased individualization of post-loading induction and maintenance doses based on CLCR is required to achieve the suggested exposures for efficacy (AUC24 >80/>40 mg.h/L for induction/maintenance) while remaining below the exposure thresholds for toxicity (AUC24

Summary Background Infection control is critical to safe hospital care. However, how bacteria within nosocomial environments relate to space utilisation and occupancy remains poorly understood. Our aim was to characterise the hospital microbiome in the context of the closure of a tertiary hospital and the opening of a new facility. Methods Environmental swabs were collected from common and inpatient areas in the old and new hospitals during a 12-month transition period. Microbiota characteristics were determined by 16S rRNA gene sequencing and quantitative (q)PCR. Targeted assays were used to detect Methicillin-resistant Staphylococcus aureus (MRSA) and vanB-positive Vancomycin-Resistant Enterococci (VRE). Results The transition to full occupancy in the new facility was associated with an increase in bacterial load (inpatient areas, 3 months p = 0.001; common areas, 6 months p = 0.039) and a change in microbiota composition (baseline-12 months, PERMANOVA p = 0.002). These changes were characterised by an increase in human microbiota-associated taxa, including Acinetobacter and Veillonella. Closure of the existing facility was associated with a decrease in bacterial load (p = 0.040). Detection of MRSA did not differ significantly between sites. Conclusions Occupancy is a major determinant of bacterial dispersion within hospital environments. Steady-state bacterial levels and microbiota composition provide a basis for assessment of infection control measures.

The ability of influenza A virus to evolve, coupled with increasing antimicrobial resistance, could trigger an influenza pandemic with great morbidity and mortality. Much of the 1918 influenza pandemic mortality was likely due to bacterial coinfection, including Staphylococcus aureus pneumonia. S. aureus resists many antibiotics. The lack of new antibiotics suggests alternative antimicrobials, such as bacteriophages, are needed. Potential delivery routes for bacteriophage therapy (BT) include inhalation and intravenous injection. BT has recently been used successfully in compassionate access pulmonary infection cases. Phage lysins, enzymes that hydrolyze bacterial cell walls and which are bactericidal, are efficacious in animal pneumonia models. Clinical trials will be needed to determine whether BT can ameliorate disease in influenza and S. aureus coinfection.

Ganciclovir (GCV) and valganciclovir (VGCV) are the first-line agents used to prevent and treat cytomegalovirus (CMV) infection in allogeneic haematopoietic stem cell transplant (alloHCT) patients. The aim of this work was to describe available data for the clinical pharmacokinetics, pharmacodynamics and toxicodynamics of GCV and VGCV and the potential of a therapeutic drug monitoring strategy to improve outcomes in the alloHCT population. We systematically reviewed the pharmacokinetics (dose-exposure), pharmacodynamics (exposure-efficacy) and toxicodynamics (exposure-toxicity) of GCV and VGCV in alloHCT patients with CMV infection. Studies including alloHCT patients treated for CMV infection reporting the pharmacokinetics, pharmacodynamics and toxicodynamics of GCV or VGCV were searched for using the PUBMED and EMBASE databases from 1946 to 2019. Only studies involving participants > 12 years of age and available in the English language were included. A total of 179 patients were included in the 14 studies that met the inclusion criteria, of which 6 examined GCV pharmacokinetics only, while 8 also examined GCV pharmacodynamics and toxicodynamics. Reported pharmacokinetic parameters showed considerable interpatient variability and were different from other populations, such as solid organ transplant and human immunodeficiency virus-infected patients. Only one study found a correlation between neutropenia and elevated peak and trough GCV concentrations, with no other significant pharmacodynamic and toxicodynamic relationships identified. While therapeutic drug monitoring of GCV is performed in some institutions, no association between GCV therapeutic drug monitoring and clinical outcomes was identified. Further studies of the pharmacokinetics, pharmacodynamics and toxicodynamics of GCV/VGCV in alloHCT patients are required to identify a more robust therapeutic range and to subsequently quantify the potential value of therapeutic drug monitoring of GCV/VGCV in the alloHCT population.

Background: Limited consensus exists on the optimal use of antifungal agents to prevent invasive fungal infection in the early post allogeneic hematopoietic stem cell transplant (alloHCT) period, particularly when patients cannot tolerate oral medication administration. Methods: We undertook a retrospective observational cohort study to assess the tolerability, efficacy, and cost of a new antifungal prophylaxis pathway at a major tertiary alloHCT centre. Patients aged ≥16 years who underwent alloHCT between February 2018 and October 2019 (cohort 1) or between April 2020 and November 2021 (cohort 2) were included. In both cohorts, first line prophylactic therapy was oral posaconazole. The second line drugs where oral therapy was unable to be administered were intravenous voriconazole (cohort 1) versus intravenous posaconazole (cohort 2). Results: There were 142 patients enrolled in the study, 71 in each cohort. The proportion of patients remaining on first-line prophylaxis or progressing to second-, third-, and fourth-line options was 22.5%, 39.4%, 29.6%, and 8.5% in cohort 1 and 39.4%, 59.2%, 1.4%, and 0% in cohort 2, respectively. The frequency of neuropsychiatric adverse events was significantly higher in cohort 1 compared to cohort 2 (49.3% vs. 19.8%, p = .0004). Occurrence of proven and probable fungal infections was not significantly different between cohorts. Antifungal drug expenditure was $359 935 (AUD) more in cohort 1 ($830 486 AUD) compared to cohort 2 ($477 149 AUD). Conclusion: The antifungal prophylaxis pathway used in cohort 2 resulted in reduced antifungal-associated adverse effects, less patients requiring progression to 3rd and 4th line prophylaxis and reduced antifungal drug costs. Refereed/Peer-reviewed

IntroductionThere has been renewed interest in the therapeutic use of bacteriophages (phages); however, standardised therapeutic protocols are lacking, and there is a paucity of rigorous clinical trial data assessing efficacy.Methods and analysisWe propose an open-label, single-arm trial investigating a standardised treatment and monitoring protocol for phage therapy. Patients included will have exhausted other therapeutic options for control of their infection and phage therapy will be administered under Australia’s Therapeutic Goods Administration Special Access Scheme. A phage product with highin vitroactivity against the targeted pathogen(s) must be available in line with relevant regulatory requirements. We aim to recruit 50–100 patients over 5 years, from any public or private hospitals in Australia. The standardised protocol will specify clinical assessments and biological sampling at scheduled time points. The primary outcome is safety at day 29, assessed by the frequency of adverse events, and overseen by an independent Data Safety Monitoring Board. Secondary outcomes include long-term safety (frequency of adverse events until at least 6 months following phage therapy), and feasibility, measured as the proportion of participants with>80% of minimum data available for analysis. Additional endpoints assessed include clinical response, patient/guardian reported quality of life measures, phage pharmacokinetics, human host immune responses and microbiome analysis. All trial outcomes will be summarised and presented using standard descriptive statistics.Ethics and disseminationParticipant inclusion will be dependent on obtaining written informed consent from the patient or guardian. The trial protocol was approved by the Sydney Children’s Hospitals Network Human Research Ethics Committee in December 2021 (Reference 2021/ETH11861). In addition to publication in a peer-reviewed scientific journal, a lay summary of study outcomes will be made available for participants and the public on the Phage Australia website (https://www.phageaustralia.org/).Trial registration numberRegistered on ANZCTR, 10 November 2021 (ACTRN12621001526864; WHO Universal Trial Number: U1111-1269-6000).

Helicobacter pylori infection is responsible for considerable morbidity and mortality worldwide, and eradication rates are falling in many countries, primarily due to clarithromycin and metronidazole resistance.There is a paucity of contemporary Australian data, which we sought to address by evaluating local rates of resistance of H. pylori to amoxicillin, clarithromycin, metronidazole and tetracycline over the past 20 years.All gastric biopsy specimens collected at endoscopy to detect H. pylori infection at a single centre underwent routine culture and antibiotic susceptibility testing between 1998 and 2017. Specimens from 12 842 patients were cultured for H. pylori, of which 1473 positive cultures were tested for antibiotic susceptibility.Antibiotic resistance to clarithromycin increased by 3.7% per year (incidence rate ratio [IRR] 1.037; P = 0.014) over 20 years, with a corresponding 5.0% annual increase in minimum inhibitory concentration (MIC) (odds ratio 1.050; P 0.001). Since 2010, average clarithromycin resistance has exceeded 20%, with25% of isolates resistant in the past 2 years of data capture. In contrast, rates of resistance to metronidazole (35.3%), amoxicillin (0.14%) and tetracycline (0.34%) and their MIC have remained stable. Review of a representative sample (n = 120; 8%) of these patients revealed that only 5% had documented prior H. pylori eradication therapy.Over the past 20 years there has been a substantial rise in clarithromycin resistance, with stable metronidazole resistance and low rates of resistance to amoxicillin and tetracycline. Current first-line H. pylori eradication therapy may fail to achieve adequate eradication rates, and optimal first-line therapy in Australia should be revisited.

Clonal complex 398 (CC398) livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) has been reported worldwide in a variety of food-animal species. Although CC398 is synonymous with LA-MRSA, community-associated MRSA (CA-MRSA) variants have emerged, including the Panton-Valentine leukocidin (PVL)-positive ST398-V and ST398 single-locus variant ST1232-V, and the PVL-negative ST398-V clones. Using comparative genomic analysis, we determined whether ten CC398 MRSA bacteraemia episodes recently identified in Australia were due to LA-MRSA or CA-MRSA CC398. Isolates were sourced from the Australian Group on Antimicrobial Resistance S. aureus surveillance programme and episodes occurred across Australia. Whole-genome sequencing (WGS) and phylogenetic comparison of the ten CC398 bacteraemia isolates with previously published CC398 MRSA whole-genome sequences identified that the Australian CC398 isolates were closely related to the human-associated II-GOI clade and the livestock-associated IIa clade. The identified CC398 MRSA clones were: PVL-positive ST1232-V (5C25), PVL-negative community-associated ST398-V (5C25) and livestock-associated ST398-V (5C25). Our findings demonstrate the importance of using WGS and comparing the sequences with international sequences to distinguish between CC398 CA-MRSA and LA-MRSA and to determine the isolates' origin. Furthermore, our findings suggest that CC398 CA-MRSA has become established in the Australian community and that ST398-V (5C25) LA-MRSA is now widespread in Australian piggeries. Our study emphasises the need for national One Health antimicrobial resistance surveillance programmes to assist in monitoring the ongoing epidemiology of MRSA and other clinically significant antimicrobial-resistant organisms.

The ability of influenza A virus to evolve, coupled with increasing antimicrobial resistance, could trigger an influenza pandemic with great morbidity and mortality. Much of the 1918 influenza pandemic mortality was likely due to bacterial coinfection, including

Additional file 5: Table S4. Antibiotic use according to class of antibiotic during study period and annual hospital use 2017-2018.

Additional file 10: Table S9. Multivariate regression analysis of clinical variables and resistance genes.

Additional file 2: Table S1. Patient co-location categories that were assigned to determine spatial relation between patients.

Additional file 6: Table S5. Significant correlations between detected AMR genes and bacterial taxa (n=24 patients)

Additional file 9: Table S8. Univariate analysis of clinical variables and resistance genes.

Additional file 3: Table S2. Primer sequences of antibiotic resistance and positive control (16S rRNA) genes for quantitative PCR.

Additional file 8: Table S7. Distribution of resistance genes according to patient location on the ward.

Additional file 7: Table S6. Proportion of genes detected in shotgun metagenomic sequencing and qPCR analysis.

Microsporum canis is a dermatophyte known to cause superficial skin infections. In immunocompromised patients, it can lead to invasive dermatophytosis. We present a case of biopsy-proven left knee mycetoma caused by M canis in a renal transplant patient. Identification of M canis was achieved via sequencing of the internal transcribed spacer regions. Treatment involved surgical debridement, oral posaconazole, and reduction in immunosuppression. In addition, we provide a review of current literature on invasive M canis infections.

Background Antimicrobial resistance (AMR) represents a profound global health threat. Reducing AMR spread requires the identification of transmission pathways. The extent to which hospital wards represent a venue for substantial AMR transmission in low- and middle-income countries settings is poorly understood. Methods Rectal swabs were obtained from adult male inpatients in a “Nightingale” model general medicine ward in Yangon, Myanmar. Resistome characteristics were characterised by metagenomic sequencing. AMR gene carriage was related to inter-patient distance (representing inter-patient interaction) using distance-based linear models. Clinical predictors of AMR patterns were identified through univariate and multivariate regression. Results Resistome similarity showed a weak but significant positive correlation with inter-patient distance (r = 0.12, p = 0.04). Nineteen AMR determinants contributed significantly to this relationship, including those encoding β-lactamase activity (OXA-1, NDM-7; adjusted p dfrA14, adjusted p = 0.0495), and chloramphenicol resistance (catB3, adjusted p = 0.002). Clinical traits of co-located patients carrying specific AMR genes were not random. Specifically, AMR genes that contributed to distance-resistome relationships (OXA-1, catB3, dfrA14) mapped to tuberculosis patients, who were placed together according to ward policy. In contrast, patients with sepsis were not placed together, and carried AMR genes that were not spatially significant or consistent with shared antibiotic exposure. Conclusions AMR dispersion patterns primarily reflect the placement of particular patients by their condition, rather than AMR transmission. The proportion of AMR determinants that varied with inter-patient distance was limited, suggesting that nosocomial transmission is a relatively minor contributor to population-level carriage.

Importance Methicillin-resistantStaphylococcus aureus(MRSA) bacteremia is associated with mortality of more than 20%. Combining standard therapy with a β-lactam antibiotic has been associated with reduced mortality, although adequately powered randomized clinical trials of this intervention have not been conducted. Objective To determine whether combining an antistaphylococcal β-lactam with standard therapy is more effective than standard therapy alone in patients with MRSA bacteremia. Design, Setting, and Participants Open-label, randomized clinical trial conducted at 27 hospital sites in 4 countries from August 2015 to July 2018 among 352 hospitalized adults with MRSA bacteremia. Follow-up was complete on October 23, 2018. Interventions Participants were randomized to standard therapy (intravenous vancomycin or daptomycin) plus an antistaphylococcal β-lactam (intravenous flucloxacillin, cloxacillin, or cefazolin) (n = 174) or standard therapy alone (n = 178). Total duration of therapy was determined by treating clinicians and the β-lactam was administered for 7 days. Main Outcomes and Measures The primary end point was a 90-day composite of mortality, persistent bacteremia at day 5, microbiological relapse, and microbiological treatment failure. Secondary outcomes included mortality at days 14, 42, and 90; persistent bacteremia at days 2 and 5; acute kidney injury (AKI); microbiological relapse; microbiological treatment failure; and duration of intravenous antibiotics. Results The data and safety monitoring board recommended early termination of the study prior to enrollment of 440 patients because of safety. Among 352 patients randomized (mean age, 62.2 [SD, 17.7] years; 121 women [34.4%]), 345 (98%) completed the trial. The primary end point was met by 59 (35%) with combination therapy and 68 (39%) with standard therapy (absolute difference, −4.2%; 95% CI, −14.3% to 6.0%). Seven of 9 prespecified secondary end points showed no significant difference. For the combination therapy vs standard therapy groups, all-cause 90-day mortality occurred in 35 (21%) vs 28 (16%) (difference, 4.5%; 95% CI, −3.7% to 12.7%); persistent bacteremia at day 5 was observed in 19 of 166 (11%) vs 35 of 172 (20%) (difference, −8.9%; 95% CI, −16.6% to −1.2%); and, excluding patients receiving dialysis at baseline, AKI occurred in 34 of 145 (23%) vs 9 of 145 (6%) (difference, 17.2%; 95% CI, 9.3%-25.2%). Conclusions and Relevance Among patients with MRSA bacteremia, addition of an antistaphylococcal β-lactam to standard antibiotic therapy with vancomycin or daptomycin did not result in significant improvement in the primary composite end point of mortality, persistent bacteremia, relapse, or treatment failure. Early trial termination for safety concerns and the possibility that the study was underpowered to detect clinically important differences in favor of the intervention should be considered when interpreting the findings. Trial Registration ClinicalTrials.gov Identifier:NCT02365493

Aim The objective was to study the long-term (lifetime) cost effectiveness of four different hepatitis C virus (HCV) treatment models of care (MOC) with directly acting antiviral drugs. Methods A cohort Markov model-based probabilistic cost-effectiveness analysis (CEA) was undertaken extrapolating to up to 30 years from cost and outcome data collected from a primary study involving a real-life Australian cohort. In this study, noncirrhotic patients treated for HCV from 1 March 2016 to 28 February 2017 at four major public hospitals and liaising sites in South Australia were studied retrospectively. The MOC were classified depending on the person providing patient workup, treatment and monitoring into MOC1 (specialist), MOC2 (mixed specialist and hepatitis nurse), MOC3 (hepatitis nurse) and MOC4 (general practitioner, GP). Incremental costs were estimated from the Medicare perspective. Incremental outcomes were estimated based on the quality-adjusted life years (QALY) gained by achieving a sustained virological response. A cost-effectiveness threshold of Australian dollar 50 000 per QALY gained, the implicit criterion used for assessing the cost-effectiveness of new pharmaceuticals and medical services in Australia was assumed. Net monetary benefit (NMB) estimates based on this threshold were calculated. Results A total of 1373 patients, 64% males, mean age 50 (SD ±11) years, were studied. In the CEA, MOC4 and MOC2 clearly dominated MOC1 over 30 years with lower costs and higher QALYs. Similarly, NMB was the highest in MOC4, followed by MOC2. Conclusion Decentralized care using GP and mixed consultant nurse models were cost-effective ways of promoting HCV treatment uptake in the setting of unrestricted access to new antivirals.

In March 2016, the Australian government offered unrestricted access to direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) to the entire population. This included prescription by any medical practitioner in consultation with specialists until sufficient experience was attained. We sought to determine the outcomes and experience over the first twelve months for the entire state of South Australia. We performed a prospective, observational study following outcomes of all treatments associated with the state's four main tertiary centres. A total of 1909 subjects initiating DAA therapy were included, representing an estimated 90% of all treatments in the state. Overall, SVR12 was 80.4% in all subjects intended for treatment and 95.7% in those completing treatment and follow-up. 14.2% were lost to follow-up (LTFU) and did not complete SVR12 testing. LTFU was independently associated with community treatment via remote consultation (OR 1.50, 95% CI 1.04-2.18, P = .03), prison-based treatment (OR 2.02, 95% CI 1.08-3.79, P = .03) and younger age (OR 0.98, 95% CI 0.97-0.99, P = .05). Of the 1534 subjects completing treatment and follow-up, decreased likelihood of SVR12 was associated with genotype 2 (OR 0.23, 95% CI 0.07-0.74, P = .01) and genotype 3 (OR 0.23, 95% CI 0.12-0.43, P ≤ .01). A significant decrease in treatment initiation was observed over the twelve-month period in conjunction with a shift from hospital to community-based treatment. Our findings support the high responses observed in clinical trials; however, a significant gap exists in SVR12 in our real-world cohort due to LTFU. A declining treatment initiation rate and shift to community-based treatment highlight the need to explore additional strategies to identify, treat and follow-up remaining patients in order to achieve elimination targets.

Background At a urology center in Australia, patients undergoing elective nonurgent urological surgery routinely receive empirical antibiotic treatment based on urinalysis (UA) prior to intervention to treat presumptive bacteriuria. Sterilization of urine with empirical antibiotics in procedures involving stone manipulation and mucosal disruption in the genitourinary system has been shown to reduce infection risks but whether this translates to low-risk urological interventions is not clear. Methods Patients undergoing outpatient elective urological procedures during a 3-month period between September and November 2017 were retrospectively reviewed. Patient demographics, results of urinalyses, empirical antibiotic use, and data surrounding post-intervention complications were collected and reviewed. Results were analyzed using SPSS v 25. Results Of 119 patients, 111 underwent a pre-procedure urinalysis. Fifty-eight percent (n = 64) of patients were treated with empiric antibiotics pre-operatively based on a positive UA (defined as the presence of urinary leukocytes or nitrites). Fifty-five percent (n = 41) of patients who received empirical antibiotics returned a positive urine culture, and only 49 percent (n = 20) of those receiving antibiotics cultured organisms susceptible to initial antibiotics prescribed. 1 Death, 3 incidences of bacteremia, and 10 incidences of bacteriuria up to 2 weeks occurred post-intervention in this cohort. There was no discernible risk of adverse events based on a composite of post-intervention death, bacteremia and bacteriuria in patients with a positive pre-procedural UA (n = 67/111, RR0.67 CI 0.49–0.91, P = 0.10). Pre-procedural sterilized urine similarly did not demonstrated any reduced risk of post-intervention adverse outcomes (n = 77/119, RR1.02 CI 0.64–1.63, P = 0.94). Conclusion This study demonstrated no increased risk of post-operative infection in patients with a positive urinalysis or urine culture with bacteriuria prior to intervention. There was a high use of broad-spectrum antibiotic as a reflex to positive urinalyses alone highlighting an avenue for improved anti-microbial stewardship. More research is needed to guide clinicians on the role of urine cultures and antibiotics prior to non-urgent urological procedures. Disclosures All authors: No reported disclosures.

Changes in the pharmacokinetics of piperacillin in febrile neutropenic patients have been reported to result in suboptimal exposures. This study aimed to develop a population pharmacokinetic model for piperacillin and perform dosing simulation to describe optimal dosing regimens for hematological malignancy patients with febrile neutropenia. Concentration-time data were obtained from previous prospective observational pharmacokinetic and interventional therapeutic drug monitoring studies. Nonparametric population pharmacokinetic analysis and Monte Carlo dosing simulations were performed with the Pmetrics package for R. A two-compartment model, with between-subject variability for clearance (CL), adequately described the data from 37 patients (21 males, age of 59 ± 12 years [means ± standard deviations] and weight of 77 ± 16 kg). Parameter estimates were CL of 18.0 ± 4.8 liters/h, volume of distribution of the central compartment of 14.3 ± 7.3 liters, rate constant for piperacillin distribution from the central to peripheral compartment of 1.40 ± 1.35 h −1 , and rate constant for piperacillin distribution from the peripheral to central compartment of 4.99 ± 7.81 h −1 . High creatinine clearance (CL CR ) was associated with reduced probability of target attainment (PTA). Extended and continuous infusion regimens achieved a high PTA of >90% for an unbound concentration of piperacillin remaining above the MIC ( fT >MIC ) of 50%. Only continuous regimens achieved >90% PTA for 100% fT >MIC when CL CR was high. The cumulative fraction of response (FTA, for fractional target attainment) was suboptimal (fT >MIC . FTA was maximized with prolonged infusions. Overall, changes in piperacillin pharmacokinetics and the consequences on therapeutic dosing requirements appear similar to those observed in intensive care patients. Guidelines should address the altered dosing needs of febrile neutropenic patients exhibiting high CL CR or with known/presumed infections from high-MIC bacteria.

A 22-year-old woman with no significant medical history preented to an Australian hospital in 2014 with a 24-h history of acute ight upper quadrant pain, fever and rigors. The pain was acute, aking her from sleep, rated 10/10 in severity and radiated to her ight shoulder tip. There were no neurological, respiratory, genital, rinary or bowel complaints. Initial observations were normal apart from fever of 39 ◦C. xamination revealed tenderness in the right upper quadrant nd a positive Murphy’s sign but was otherwise unremarkble. Blood tests showed a normal total white cell count of .43 × 109[reference range [RR] 4.0–11.0 × 109/L] with moderate ymphopenia of 0.58 × 109[RR 1.5–3.5 × 109/L]. C-reactive protein as modestly elevated at 33 mg/L [RR < 8.0 mg/L]. She had noral electrolytes, liver transaminases and lipase. Pregnancy was xcluded. Blood cultures collected prior to antibiotics were negtive. Chest X-ray demonstrated clear lung fields and no free gas. bdominal ultrasound showed a minimally thickened but tender allbladder without calculi. A sexual history was obtained and she reported having a single egular partner with whom she used condoms. She did not comlain of localized vaginal discomfort or discharge. Her pelvic and aginal examination was normal. The patient was diagnosed with acalculous cholecystitis and as charted analgesia and antibiotics. The following day a aparoscopic cholecystectomy was performed without complicaion. Histopathology of the gallbladder showed serositis with an nflammatory infiltrate composed mainly of neutrophils within he subserosal adipose tissue. There was only scant mucosal

Introduction: Although infections are a leading cause of morbidity and mortality in MDS patients, there is limited evidence on causative organisms and resistance patterns in this patient population. This study, the largest series of infection in MDS patients, seeks to comprehensively analyse infection in this cohort. Method: CT scan, microbiology results and hospital admission ICD codes from January 1999 to April 2017 were analysed for 657 MDS patients enrolled in the South Australian MDS (SA-MDS) registry. Cox regression analysis was performed to ascertain risk factors for developing infection. Results: There were 531 primary and 126 therapy-related myeloid neoplasm (t-MN) patients with median age of 69.2 (18-97) years. According to Revised International Prognostic Scoring System (IPSS-R), 44.7% of patients were classified as Intermediate, High and Very High risk. The majority of the cohort (377/657; 57.3%) received best supportive care and 265 had disease modifying therapy including azacitidine (n=142), chemotherapy (n=74) and stem cell transplantation (SCT) (n=25). There were 2450 hospital admissions and 1312(53.5%) were infection-related, in 464/657 patients. The most common sites of infection were lower respiratory tract infections (LRTI) n=449(33.2%), fever with no known source n=356(26.3%) and skin and soft tissue (SSTI; 235, 17.3%). During the study period, 1613/16176 (10%) of microbiology tests were positive. The most common positive tests were blood cultures (494, 30.6%), respiratory viral PCR (227, 14.0%) and bacteriology (other sites; 216, 13.4%). The most common isolates were bacteria (67.3%) followed by viruses (28.1%) and fungi (4.6%). The most common bacteria were gram negative bacilli (GNB); E. coli n=81(12%), Pseudomonas spp. n=64(9%) and Klebsiella spp. n=56(8%), and the most common gram-positive isolates were Staphylococcus aureus n=114(20%) and Enterococcus spp. (37, 7%). There were 192 episodes of bacteraemia in 179 patients. The most common causative organisms were E. coli n=32(16.7%), Klebsiella spp. n=18(9.4%) Pseudomonas spp. n=25(13%), coagulase negative staphylococci n=26(14%), Streptococcus spp. n=22(11%) and Enterococcus spp. n=14(11%). The proportion of GNB bacteremias significantly increased over time (45.8% 1999-2005; 40.0% 2006-2011 and 59.4% 2012-2017 [p=.004]) without increased resistance to commonly used antibiotics. There were 21 enterococcal bacteremias with significant increase in proportion of vancomycin resistant Enterococcus (VRE) after 2011 (p The most commonly isolated respiratory viruses were rhinovirus (98, 43.2%), influenza (34, 15%) and parainfluenza (34, 15%), Cytomegalovirus was identified in 154 specimens from 31 patients, all following SCT. 70 patients had probable or confirmed fungal infection, with 52 (74.3%) patients having positive fungal cultures or CT findings. The most common sites of fungal infection were chest n=21(76.9%), followed by skin n=5(9.6%), urine n=4(7.7%) and blood n=3(5.8%). Aspergillus n=17(44.7%) was most commonly isolated, followed by Candida spp. n=15(39.5%) and Rhizopus n=3(7.9%). We performed a Cox regression analysis of the risk factors for development of infection requiring hospitalisation, specifically with LRTI, fungal infection and bacteraemia (Table I). Significant predictors were increased age, t-MN, higher IPSS-R score and being transfusion dependent at diagnosis. Receiving disease modifying therapy was a significant risk factor for hospitalisation with fungal infection (p=0.022). Additionally, patients who had hospitalisations for infections had poorer overall survival compared to hospitalised patients without infection (p=0.002, Figure 1). Conclusions: Greater than 50% of hospital admissions in MDS patients were complicated by infection and this was associated with a significant reduction in survival. The most common sites were LRTI, followed by bacteraemia and SSTI. Bacteraemia from GNBs increased over the study period without significant change in resistance patterns, while prevalence of VRE increased since 2011. Respiratory viruses, including influenza, caused significant morbidity, suggesting a role for routine vaccination. RBC transfusion dependency, t-MN and disease modifying therapy are independent risk factors for fungal disease. This highlights a cohort of patients that would benefit from anti-fungal prophylaxis. Disclosures Hiwase: Celgene: Research Funding; Novartis: Research Funding.

While guidelines recommend empirical cefepime therapy in febrile neutropenia, the mortality benefit of cefepime has been controversial. In light of this, recent reports on pharmacokinetic changes for several antibiotics in febrile neutropenia and the consequent suboptimal exposure call for a pharmacokinetic/pharmacodynamic evaluation of current dosing. This study aimed to assess pharmacokinetic/pharmacodynamic target attainment from a 2-g intravenous (i.v.) every 8 h (q8h) cefepime regimen in febrile neutropenic patients with hematological malignancies. Cefepime plasma concentrations were measured in the 3rd, 6th, and 9th dosing intervals at 60% of the interval and/or trough point. The selected pharmacokinetic/pharmacodynamic targets were the proportion of the dosing interval (60% and 100%) for which the free drug concentration remains above the MIC ( f T >MIC ). Target attainment was assessed in reference to the MIC of isolated organisms if available or empirical breakpoints if not. The percentage of f T >MIC was also estimated by log-linear regression analysis. All patients achieved >60% f T >MIC in the 3rd and 6th dosing intervals. A 100% f T >MIC was not attained in 6/12, 4/10, and 4/9 patients in the 3rd, 6th, and 9th dose intervals, respectively, or in 14/31 (45%) of the dosing intervals investigated. On the other hand, 29/31 (94%) of trough concentrations were at or above 4 mg/liter. In conclusion, for patients with normal renal function, a high-dose 2-g i.v. q8h cefepime regimen appears to provide appropriate exposure if the MIC of the organism is ≤4 mg/liter but may fail to cover less susceptible organisms.

Objectives The objectives of this study were to describe piperacillin exposure in febrile neutropenia patients and determine whether therapeutic drug monitoring (TDM) can be used to increase the achievement of pharmacokinetic (PK)/pharmacodynamic (PD) targets. Methods In a prospective randomized controlled study (Australian New Zealand Registry, ACTRN12615000086561), patients were subjected to TDM for 3 consecutive days. Dose was adjusted in the intervention group to achieve a free drug concentration above the MIC for 100% of the dose interval (100% fT>MIC), which was also the primary outcome measure. The secondary PK/PD target was 50% fT>MIC. Duration of fever and days to recovery from neutropenia were recorded. Results Thirty-two patients were enrolled. Initially, patients received 4.5 g of piperacillin/tazobactam every 8 h or every 6 h along with gentamicin co-therapy in 30/32 (94%) patients. At the first TDM, 7/32 (22%) patients achieved 100% fT>MIC and 12/32 (38%) patients achieved 50% fT>MIC. Following dose adjustment, 11/16 (69%) of intervention patients versus 3/16 (19%) of control patients (P = 0.012) attained 100% fT>MIC, and 15/16 (94%) of intervention patients versus 5/16 (31%) of control patients (P = 0.001) achieved 50% fT>MIC. After the third TDM, the proportion of patients attaining 100% fT>MIC improved from a baseline 3/16 (19%) to 11/15 (73%) in the intervention group, while it declined from 4/16 (25%) to 1/15 (7%) in the control group. No difference was noted in the duration of fever and days to recovery from neutropenia. Conclusions Conventional doses of piperacillin/tazobactam may not offer adequate piperacillin exposure in febrile neutropenic patients. TDM provides useful feedback of dosing adequacy to guide dose optimization.

This study assessed the pharmacokinetics and dosing adequacy of piperacillin in febrile neutropenic patients after the first dose. Pharmacokinetic analysis was performed using noncompartmental methods. We observed an elevated volume of distribution (29.7 ± 8.0 liters [mean ± standard deviation]) and clearance (20.2 ± 7.5 liters/h) compared to data from other patient populations. Antibiotic exposure did not consistently result in therapeutic targets. We conclude that alternative dosing strategies guided by therapeutic drug monitoring may be required to optimize exposure.

Objectives Inappropriate antimicrobial use drives antimicrobial resistance and is a global public health problem. This study examined whether withholding antimicrobial susceptibilities in combination with interpretive comments on microbiological reports influenced the decision to inappropriately prescribe antibiotics in a controlled survey. Methods Seventy junior doctors attending educational sessions were given one of two surveys describing four clinical case vignettes (scenarios) in which antimicrobial treatment was not indicated. They were asked to select their preferred treatment from multiple choices. In the scenarios labelled 'A', the laboratory report did not report antibiotic susceptibilities, but included comments from the microbiologist. In the scenarios labelled 'B', the laboratory report included full organism identification and susceptibility results without additional comments. Results For scenarios 1, 2 and 3 there was a significantly higher probability ( P < 0.01) that the doctor selected an answer involving antibiotic treatment if he/she received the 'B' version of the scenario where reports included antimicrobial susceptibilities, but no interpretive comments. This was significant in both interns and more senior doctors. In scenario 4, of which there were two versions, there was no difference seen in the answers between the groups given scenario A or B. Conclusions The results of this survey suggest that withholding antimicrobial susceptibility results in combination with interpretive comments on microbiology reports significantly influences the decision of junior doctors to prescribe antibiotics in low-acuity outpatient setting scenarios (represented in scenarios 1-3), but not in inpatient scenarios (represented in scenario 4).

Puvesh Punj, Renjy Nelson, Sarah Gardiner, Michelle Lodge, Stephen R Graves, Morgyn S Warner

Sudden and unexpected nontraumatic death in individuals with asplenia or hyposplenia is usually due to fulminant bacterial sepsis, most often involving Streptococcus pneumoniae, Neisseria meningitidis, and Hemophilus influenzae. We report a case of a previously well 40-year-old man who died 5 hours after hospital admission. At autopsy Waterhouse-Friderichsen syndrome was identified and Capnocytophaga canimorsus was subsequently isolated on antemortem blood cultures. Infection of humans with this organism is most often due to dog bite or contact. Upon specific inquiry it was ascertained that 2 days before admission the deceased had suffered a superficial bite to his hand by his pet Staffordshire Bullterrier dog. His relevant history included a previous splenectomy following blunt abdominal trauma. Asplenia and hyposplenia at autopsy should prompt microbiological testing with consideration of unusual organisms such as C. canimorsus. Although histories of animal contact or injury are often not available at the time of autopsy, this should also be considered in cases of apparent fulminant sepsis. In individuals with asplenia or hyposplenia, dog bites do not have to involve excessive tissue trauma, vascular compromise, or blood loss to be lethal. Language: en

Lemierre syndrome refers to necrotizing infections of the head due to Fusobacterium necrophorum and has been called the ‘forgotten disease’ due to its rarity in the antibiotic era. Recently, however, more cases have been documented in the literature suggesting that there has been an increase in incidence. A 10-year-old boy is reported who had a five-day history of ear infection, with the development of fever, drowsiness and ipsilateral neck swelling. Unexpected cardiac arrest occurred soon after medical assessment. At autopsy, right otitis media was demonstrated with extension of suppurative infection into subcutaneous tissues behind the ear and also into the extradural space at the lateral end of the petrous temporal bone. There was also septic thrombophlebitis of the adjacent sigmoid sinus, but no evidence of meningitis. This case demonstrates yet another infectious condition that may be associated with rapid deterioration and unexpected death in childhood. An autopsy approach to suspected sepsis in childhood is outlined.

Two cell surface proteins (nectin-1/HveC and nectin-2/HveB) shown previously to serve as receptors for the entry of herpes simplex virus 1 (HSV-1) wild-type and/or mutant strains were found to serve also as receptors for HSV-1-induced cell fusion. Transfection with genomic DNA from a syncytial HSV-1 strain encoding wild-type gD resulted in fusion of Chinese hamster ovary (CHO) cells expressing nectin-1 but not of cells expressing nectin-2. In contrast, transfection with DNA from a related HSV-1 strain encoding the mutant Rid1 form of gD resulted in fusion of CHO cells expressing either receptor but not of control cells. These results are consistent with the ability of each receptor to mediate entry of viruses expressing wild-type or Rid1 gD and with results obtained previously with HVEM (HveA), a third HSV-l entry receptor. Undersulfation of GAGs in receptor-expressing cell lines predictably reduced susceptibility to HSV-l infection. In contrast, susceptibility to cell fusion mediated by HVEM or nectin-1 was not reduced. Undersulfation of GAGs partially inhibited cell fusion mediated by nectin-2. We conclude that HSV-1-induced cell fusion requires a gD-binding entry receptor, that ability of an HSV-1 strain to use HVEM, nectin-2 or nectin-1 for cell fusion depends on the allele of gD expressed and that GAGs may influence cell fusion, dependent on the gD-binding receptor used, but are less important for cell fusion mediated by HVEM, nectin-2 or nectin-l than for viral entry.

We identified and cloned a cellular mediator of herpes simplex virus (HSV) entry. Hamster and swine cells resistant to viral entry became susceptible upon expression of a human cDNA encoding this protein, designated HVEM (for herpesvirus entry mediator). HVEM was shown to mediate the entry of several wild-type HSV strains of both serotypes. Anti–HVEM antibodies and a soluble hybrid protein containing the HVEM ectodomain inhibited HVEM–dependent infection but not virus binding to cells. Mutations in the HSV envelope glycoprotein gD significantly reduced HVEM–mediated entry. The contribution of HVEM to HSV entry into human cells was demonstrable in activated T cells. HVEM, the first identified mediator of HSV entry, is a new member of the TNF/NGF receptor family.