Background: A prolonged outbreak of carbapenemase-producing Serratia marcescens (CPSM) was identified in our quaternary healthcare center over a 2-year period from 2015 through 2017. A reservoir of IMP-4–producing S. marcescens in sink drains of clinical hand basins (CHB) was implicated in propagating transmission, supported by evidence from whole-genome sequencing (WGS). We assessed the impact of manual bioburden reduction intervention on further transmission of CPSM. Methods: Environmental sampling of frequently touched wet and dry areas around CPSM clinical cases was undertaken to identify potential reservoirs and transmission pathways. After identifying CHB as a source of CPSM, a widespread annual CHB cleaning intervention involving manual scrubbing of sink drains and the proximal pipes was implemented. Pre- and postintervention point prevalence surveys (PPS) of CHB drains performed to assess for CPSM colonization. Surveillance for subsequent transmission was conducted through weekly screening of patients and annual screening of CHB in transmission areas, and 6-monthly whole-hospital PPS of patients. All CPSM isolates were assessed by WGS. Results: In total, 6 patients were newly identified with CPSM from 2015 to 2017 (4.3 transmission events per 100,000 surveillance bed days [SBD]; 95% CI, 1.6–9.4). All clinical CPSM isolates were linked to CHB isolates by WGS. The CHB cleaning intervention resulted in a reduction in CHB colonization with CPSM in transmission areas from 72% colonization to 28% (ARR, 0.44; 95% CI, 0.25–0.63). A single further clinical case of CPSM linked to the CHB isolates was detected over 2 years of surveillance from 2017 to 2019 following the implementation of the annual CHB cleaning program (0.7 transmissions per 100,000 SBD; 95% CI, 0.0–3.9). No transmissions were linked to undertaking the cleaning intervention. Conclusions: A simple intervention targeted at reducing the biological burden of CPSM in CHB drains at regular intervals was effective in preventing transmission of carbapenemase-producing Enterobacterales from the hospital environment to patients over a prolonged period of intensive surveillance. These findings highlight the importance of detailed cleaning for controlling the spread of multidrug-resistant organisms from healthcare environments.

Funding: None

Disclosures: Jason Kwong, Austin Health

Schizophrenia is associated with altered neural development. We assessed neurological soft signs (NSS) and dermatoglyphic anomalies (total a–b ridge count (TABRC) and total finger ridge count) in 15 pairs of twins concordant and discordant for schizophrenia. Within-pair differences in both NSS and TABRC scores were significantly greater in discordant compared to concordant monozygotic pairs. There was no significant difference in NSS and TABRC scores between subjects with schizophrenia and their co-twins without the illness. However, monozygotic discordant twins with schizophrenia had higher ABRCs on their right hands compared to their co-twins without the illness. These findings suggest that an unidentified environmental event acting between weeks 6 and 15 of gestation affects the development of monozygotic twins who go on to develop schizophrenia but does not have a corresponding effect on their co-twins who do not develop the illness. The effect of such an event on dermatoglyphic profiles appears lateralised to the right hand in affected twins.

We sought to define the prevalence of echocardiographic abnormalities in long-term survivors of paediatric hematopoietic stem cell transplantation and determine the utility of screening in asymptomatic patients. We analysed echocardiograms performed on survivors who underwent hematopoietic stem cell transplantation from 1982 to 2006. A total of 389 patients were alive in 2017, with 114 having an echocardiogram obtained ⩾5 years post-infusion. A total of 95 patients had echocardiogram performed for routine surveillance. The mean time post-hematopoietic stem cell transplantation was 13 years. Of 95 patients, 77 (82.1%) had ejection fraction measured, and 10/77 (13.0%) had ejection fraction z-scores ⩽−2.0, which is abnormally low. Those patients with abnormal ejection fraction were significantly more likely to have been exposed to anthracyclines or total body irradiation. Among individuals who received neither anthracyclines nor total body irradiation, only 1/31 (3.2%) was found to have an abnormal ejection fraction of 51.4%, z-score −2.73. In the cohort of 77 patients, the negative predictive value of having a normal ejection fraction given no exposure to total body irradiation or anthracyclines was 96.7% at 95% confidence interval (83.3–99.8%). Systolic dysfunction is relatively common in long-term survivors of paediatric hematopoietic stem cell transplantation who have received anthracyclines or total body irradiation. Survivors who are asymptomatic and did not receive radiation or anthracyclines likely do not require surveillance echocardiograms, unless otherwise indicated.

Bacterial cultures exposed to iron-doped apatite nanoparticles (IDANPs) prior to the introduction of antagonistic viruses experience up to 2.3 times the bacterial destruction observed in control cultures. Maximum antibacterial activity of these bacteria-specific viruses, or phage, occurs after bacterial cultures have been exposed to IDANPs for 1 hr prior to phage introduction, demonstrating that IDANP-assisted phage therapy would not be straight forward, but would instead require controlled time release of IDANPs and phage. These findings motivated the design of an electrospun nanofiber mesh treatment delivery system that allows burst release of IDANPs, followed by slow, consistent release of phage for treatment of topical bacterial infections. IDANPs resemble hydroxyapatite, a biocompatible mineral analogous to the inorganic constituent of mammalian bone, which has been approved by the Food and Drug Administration for many biomedical purposes. The composite nanofiber mesh was designed for IDANP-assisted phage therapy treatment of topical wounds and consists of a superficial, rapid release layer of polyethylene oxide (PEO) fibers doped with IDANPs, followed by inner, coaxial polycaprolactone / polyethylene glycol (PCL/PEG) blended polymer fiber layer for slower phage delivery. Our investigations have established that IDANP-doped PEO fibers are effective vehicles for dissemination of IDANPs for bacterial exposure and resultant increased bacterial death by phage. In this work, slower delivery of the phage behind IDANPs was accomplished using coaxial, electrospun fibers composed of PCL/PEG polymer blend.

We present a new monthly index of the yields on junk bonds (high risk, high yield bonds) for the period 1910–1955. This index supplements the indexes of government bond yields, and Aaa and Baa corporate bond yields economic historians have relied on previously to describe the long-term risk spectrum. First, we describe our sources and methods. Then we show that our junk bond index contains information that is not in the closest alternative, and suggest some ways that the junk bond index could be used to enrich our understanding of the turbulent middle years of the twentieth century.