The role of initial specimen diversion devices (ISDDs) in preventing contamination of central venous catheter (CVC) blood cultures is undefined. A model to simulate CVC colonization and contamination compared standard cultures with ISDD technique. ISDD detected 100% of colonized CVCs while decreasing false-positive cultures from 36% to 16%.

The negative predictive value of blaCTX-M on BCID2 for ceftriaxone resistance in E. coli and K. pneumoniae group was 97% and 94%, respectively. Creation of a genotypic antibiogram led to updated local guidance for clinicians to utilize for empiric treatment of Enterobacterales bloodstream infections identified via rapid diagnostics.

Background: Antibiotics are frequently prescribed in patients with COVID-19 infections to treat secondary bacterial pneumonia. The pneumonia panel (PNP) is a molecular diagnostic tool that rapidly detects 33 bacterial and viral targets. The utility of this panel in COVID-19 patients and how it may direct antibiotic use is unknown. We sought to understand the utilization of PNP in patients with COVID-19 pneumonia over time by comparing clinical parameters, microbiologic results, and antibiotic use between May–December 2020 and January–July 2022. Methods: We implemented the PNP in May 2020 with antimicrobial stewardship guidance, provider education, and order restriction to critical care and infectious disease clinicians. From February–July 2021 prescribers received regular structured antimicrobial stewardship feedback regarding PNP results; from August 2021 to January 2022, no antimicrobial stewardship feedback was provided; from February to July 2022, intermittent feedback was provided. We compared PNP and culture results from sputum or bronchoalveolar lavage samples and antibiotic use and modification within 24 hours of PNP result from patients with confirmed COVID-19 pneumonia between May–December 2020 and January–July 2022. Clinical data and antibiotic use were abstracted through chart review. We excluded patients who died within 72 hours of PNP, those who had concurrent nonpulmonary infections, and those whose COVID-19 test was >30 days prior. Results: We included 114 patients in 2020 and 71 patients in 2022. The overall median age was 61 years, 71% were male, and 66% were mechanically ventilated without statistical differences between the cohorts, including their comorbidities. Acute or worsening hypoxia remained the predominant indication for PNP (77% in 2020 vs 75% in 2022, NS). The median number of days between admission and PNP was 4 (IQR, 1–8) in 2020 versus 3 (IQR, 1–7), and the difference was not significant. PNP and culture results in Table 1 show that Staphylococcus aureus and Hemophilus influenzae were the pathogens most commonly identified. Table 2 describes empiric prescribing and modifications for commonly prescribed antibiotics. Prescribers used empiric cefepime and ceftriaxone more in 2020 and vancomycin more in the 2022 group; however, these were not statistically significant. Cefepime de-escalation was more common in 2022 (53% vs 28%; P = .03). Antibiotic modifications within 24 hours of PNP remained similar in 2020 vs 2022. Although vancomycin cessation was more common in 2020 (78%) versus 2022 (57%), the difference was not statistically significant. Conclusions: With ASP guidance, PNP may be a useful tool to stop or target antibiotics for secondary bacterial pneumonia in COVID-19 pneumonia. Early vancomycin cessation (prior to culture results) may be an enduring consequence of PNP implementation.

Disclosures: None

As the coronavirus disease 2019 (COVID-19) continues to circulate, testing strategies are of the utmost importance. Given national shortages of testing supplies, personal protective equipment, and other hospital resources, diagnostic stewardship is necessary to aid in resource management. We report the low utility of serial testing in a low-prevalence setting.

Neutrophil–lymphocyte ratio has been associated with clinical outcomes in several groups of cardiac patients, including patients with coronary artery disease, cardiac failure, and cardiac transplant recipients. We hypothesised that pre- and/or post-operative haematological cell counts are associated with clinical outcomes in children undergoing cardiac surgery for CHD. We performed a post hoc analysis of data collected as part of a prospective observational cohort study (n = 83, data available n = 47) of children evaluated for glucocorticoid receptor levels after cardiac surgery (July 2015–January 2016). The association of neutrophil–lymphocyte ratio with low cardiac output syndrome, time to inotrope free, and vasoactive-inotropic score was examined using proportional odds analysis, cox regression, and linear regression models, respectively. A majority (80%) of patients were infants (median/interquartile range 4.1/0.2–7.6 months) with conotruncal (36%) and left-sided obstructed lesions (28%). Two patients required mechanical circulatory support and three died. Higher pre-operative neutrophil–lymphocyte ratio was associated with higher cumulative odds of severe/moderate versus mild low cardiac output on post-operative day 1 (odds ratio 2.86; 95% confidence interval 1.18–6.93; p = 0.02). Pre-operative neutrophil–lymphocyte ratio was not significantly associated with time to inotrope free or vasoactive-inotrope score. Post-operative neutrophil–lymphocyte ratio was also not associated with outcomes. In children after congenital heart surgery, higher pre-operative neutrophil–lymphocyte ratio was associated with a higher chance of low cardiac output in the early post-operative period. Pre-operative neutrophil–lymphocyte ratio maybe a useful prognostic marker in children undergoing congenital heart surgery.

Hospital use of chlorhexidine (CHX) containing antiseptics to decrease nosocomial infections may promote CHX resistance among pathogenic organisms. Nosocomial bloodstream-infecting Staphylococcus aureus isolates from before and after adoption of hospital-wide CHX bathing were tested for CHX susceptibility, and no decreased susceptibility or resistance-promoting genes were discovered.

Infect Control Hosp Epidemiol 2017;38:873–875

Classical molecular dynamics (MD), along with a bond-order potential for GaAs, has been used to study threshold displacement energies (E d) of Ga and As recoils. Considering the crystallographic symmetry of GaAs, recoil events are confined in four unit stereographic triangles. To investigate the displacement energy’s dependence on crystallographic orientation, more than 3600 recoil events were simulated to uniformly sample values of E d. Various defect configurations produced at these low energy recoils and the separation distances of Frenkel pairs were quantified and outlined. For both Ga and As, the minimum, $E_{\rm{d}}^{{\rm{min}}}$ , is found to be 8 eV, but the maxima, $E_{\rm{d}}^{{\rm{max}}}$ , are 22 and 28 eV for Ga and As, respectively. The distribution of E d within unit stereographic triangles indicates that E d shows a weak dependence on the recoil directions, in contrast to other semiconductors. The average threshold displacement energy is 13 ± 1 eV, which is in excellent agreement with available experiments.

Basins, commonly used to bathe patients who are unable to bathe themselves, frequently become contaminated with potential pathogens and may serve as a source for nosocomial transmission. Chlorhexidine (CHG) has bactericidal activity against a broad spectrum of pathogens and is increasingly used in antiseptic patient baths. The purpose of this study was to ascertain whether basins used to administer CHG bed baths are likely to become contaminated.

Bed bath conditions were simulated by mixing 30 mL of a 4% CHG product or soap preparation to 1 L of warm (37°C) tap water in a 6-L plastic basin (Medical Action Industries). Two commercial brands of CHG (Hibiclens, Molnlycke Health Care [hereafter, CHG-A], or Scrub Care, Cardinal Health [hereafter, CHG-B]) and 1 brand of soap (SensiCare SeptiSoft, ConvaTec) were used. Basins were inoculated with 108 colony-forming units (CFUs) of 1 species of bacteria, mixed for 30 seconds, incubated for 20 minutes at room temperature, emptied, and allowed to dry for 1 hour. A 100-cm2 area on the bottom of the basin was sampled for 10 seconds in 2 directions with a cotton swab premoistened with normal saline. Swab tips were placed in 2 mL of trypticase soy broth (Difco) and vortex-mixed for 30 seconds, and the solution was quantitatively cultured on sheep blood agar (Remel). Cultures were incubated at 37°C for 24 hours, and colonies were counted and expressed as CFUs per square centimeter. Tap water with and without a bacterial inoculum served as positive and negative controls, respectively.

Monsel's solution is a common topically applied hemostatic agent used in minor dermatologic and gynecologic surgery. Clinically, because it is often stored for long periods and dispensed from a common source for multiple patients, Monsel's solution is a potential vector for transmission of infection. However, microbiologic inoculation studies and contamination surveys indicate that Monsel's solution has properties that prohibit microbial growth, making it an unlikely vector for nosocomial infection.

An outbreak of vancomycin-resistant Enterococcus faecium involving 28 infants in a neonatal intensive care unit was observed. Successful control of the outbreak was achieved following use of patient and staff cohorting, contact isolation precautions, patient and environmental surveillance cultures, environmental decontamination, molecular typing, introduction of an alcohol-based hand disinfectant, and decreased use of vancomycin.