Association Between Minimum Inhibitory Concentration, Beta-lactamase Genes and Mortality for Patients Treated With Piperacillin/Tazobactam or Meropenem From the MERINO Study.

INTRODUCTION: This study aims to assess the association of piperacillin/tazobactam and meropenem minimum inhibitory concentration (MIC) and beta-lactam resistance genes with mortality in the MERINO trial. METHODS: Blood culture isolates from enrolled patients were tested by broth microdilution and whole genome sequencing at a central laboratory. Multivariate logistic regression was performed to account for confounders. Absolute risk increase for 30-day mortality between treatment groups was calculated for the primary analysis (PA) and the microbiologic assessable (MA) populations. RESULTS: In total, 320 isolates from 379 enrolled patients were available with susceptibility to piperacillin/tazobactam 94% and meropenem 100%. The piperacillin/tazobactam nonsusceptible breakpoint (MIC >16 mg/L) best predicted 30-day mortality after accounting for confounders (odds ratio 14.9, 95% confidence interval [CI] 2.8-87.2). The absolute risk increase for 30-day mortality for patients treated with piperacillin/tazobactam compared with meropenem was 9% (95% CI 3%-15%) and 8% (95% CI 2%-15%) for the original PA population and the post hoc MA populations, which reduced to 5% (95% CI -1% to 10%) after excluding strains with piperacillin/tazobactam MIC values >16 mg/L. Isolates coharboring extended spectrum ß-lactamase (ESBL) and OXA-1 genes were associated with elevated piperacillin/tazobactam MICs and the highest risk increase in 30-day mortality of 14% (95% CI 2%-28%). CONCLUSIONS: After excluding nonsusceptible strains, the 30-day mortality difference from the MERINO trial was less pronounced for piperacillin/tazobactam. Poor reliability in susceptibility testing performance for piperacillin/tazobactam and the high prevalence of OXA coharboring ESBLs suggests that meropenem remains the preferred choice for definitive treatment of ceftriaxone nonsusceptible Escherichia coli and Klebsiella.

Supervised self-administration of outpatient parenteral antibiotic therapy: a report from a large tertiary hospital in Australia.

INTRODUCTION: Outpatient parenteral antibiotic therapy (OPAT) has become established as a standard of care in most Australian hospitals to treat a variety of infections. Since 1998, the Alternate Site Infusion Service (ASIS) has provided an OPAT service to five hospitals in southern Brisbane, Queensland, using predominantly a patient or carer administration model (self-administered, S-OPAT). The aim of this study was to evaluate outcomes of our S-OPAT programme. METHODS: Consecutive patients treated by ASIS at the Princess Alexandra Hospital from January 1, 2011 to December 31, 2011 were reviewed. Data on patient demographics, diagnoses, microbiology, antimicrobial therapy, duration, outcome, and complications were sourced from a prospectively collected database and from patient medical records. RESULTS: There were 150 episodes involving 144 patients resulting in 3520 days of OPAT; the median duration on the programme was 22 days (range 4­106 days). Patient or carer administration occurred in the majority of episodes. The most common indication by far was bone or joint infection (47% of patients), followed by infective endocarditis (9%). Staphylococcus aureus was the most frequently treated organism. The overall cure rate was 93%. On multivariate analysis, patients with two or more comorbidities had an increased risk of failure. Line-related complications occurred in 1.4/1000 catheter-days. Rash was the most common drug-related event. Despite the extensive use of broad-spectrum antibiotics there were no cases of Clostridium difficile infection during therapy and for up to 28 days post cessation of intravenous antibiotics. The cost of OPAT per patient excluding drug administration and home visits was approximately A$ 150.00/day, significantly lower than the cost of an inpatient bed, which is estimated to be A$ 500­800/day.5 CONCLUSION: OPAT using a patient or carer administration model is an effective and safe option for the management of selected patients with infection requiring intravenous antibiotics.

Infectious diseases consultations at an Australian tertiary hospital: a review of 11,511 inpatient consultations.

BACKGROUND: Infectious diseases (ID) clinicians provide an important service within tertiary hospitals. However, as a largely consultation-based service, their value can be difficult to evaluate. AIMS: A review of 13.5 years of consultations was undertaken to define the scope of the service and any changes over time. METHODS: ID consultations at the Princess Alexandra Hospital are tracked on a database, recording information including the requesting team, indication for and outcome of the consult. Incident formal inpatient consultations between July 1999 and December 2012 were reviewed retrospectively. Phone consultations, repeat consultations and ID admissions were excluded. RESULTS: Eleven thousand five hundred and eleven consultations were identified, with annual consultations increasing significantly during this period. Overall, formal consultations were performed on 1.3% of admissions. Consultations were most commonly requested by orthopaedics (14.3%) and general medicine (11.4%). The two most common syndromes triggering a consult were bloodstream infection (13.9%) and complicated soft tissue infection (7.8%). The final diagnosis was most frequently osteomyelitis (7.9%). Staphylococcus aureus (19.4%) and Pseudomonas aeruginosa (8.3%) were the most commonly identified pathogens. CONCLUSION: The demand for ID consultations has increased over time and there are likely to be many drivers of this increase. Information derived from this audit can enhance the ID service by guiding service delivery, trainee education and informing funding or accreditation applications.

Successful treatment of post-neurosurgical intracranial Mycoplasma hominis infection using gatifloxacin.

We describe two cases of intracerebral infection with Mycoplasma hominis following neurosurgery, the first after removal of a colloid cyst, the other after a craniotomy following a motor vehicle accident (MVA). Both infections were successfully treated with parenteral gatifloxacin, with ongoing clindamycin or moxifloxacin for associated osteomyelitis.