Isolation and Characterization of Phages That Bypass the Requirement for RNA-Mediated Antitermination.

Introduction: The rpoCY75N mutation in the zinc-binding domain of the ß' subunit of Escherichia coli RNA polymerase blocks the RNA-based mechanism of transcription antitermination utilized by bacteriophage HK022. Materials and Methods: Mutant phages that overcome the block imposed by the rpoCY75N mutation are described. These phages, designated "orc" (overcomes rpoC), carry mutations that create new promoters. Promoter activity was assessed by cloning the respective regions from the wild-type and orc phages into a promoterless lacZ reporter vector. Results: Reporter assays showed that the sequence originating from orc phages had significant promoter activity when compared with the equivalent sequence cloned from the parental phage. Conclusions: The newly created promoters facilitate the expression of phage genes that are essential for growth on the rpoCY75N strain by bypassing transcription terminators. The small plaque phenotype of orc phages, when grown on the mutant host, suggests that suppression of the rpoCY75N mutation is incomplete.

Demonstration of a U.S. nationwide reduction in transfusion in general surgery and a review of published transfusion reduction methodologies.

BACKGROUND: Red blood cell transfusions in surgical procedures can be lifesaving. However, recent studies show transfusions are associated with a dose-dependent increase in postoperative morbidity and mortality; hospitals and physicians have attempted to reduce them. We sought to determine the success of these efforts and review and summarize published reduction methods employed. STUDY DESIGN/METHODS: An analysis of transfusion data from ACS-NSQIP public use files of general surgical procedures for 2012 and 2018; a retrospective review of the literature surrounding general surgical transfusion reduction from 2008 to 2018. RESULTS: The rate of general surgical transfusion in the NSQIP dataset decreased from 5.5% in 2012 to 4.0% in 2018, a 27% relative reduction in transfusion. After extensive multivariable adjustment for patient risk and operative complexity, this effect remained (Odds ratio 0.65, 95% CI 0.63-0.67, p < .001). Furthermore, there was a positive correlation between specific procedure decreases in transfusion and decreases in 30-day morbidity (rho =0.41, p = .003) and mortality (rho = 0.37, p = .007). There were 866 published studies matching our search term "red blood cell transfusion reduction." Forty-four were relevant to general surgery. Seven dominant strategies for transfusion reduction by descending frequency of report included restrictive transfusion thresholds, management of preoperative anemia, perioperative interventions, educational programs, electronic clinical decision support, waste reduction, and audits of transfusion practices. CONCLUSION: Our study demonstrates a 27% decrease in general surgery transfusion between 2012 and 2018 with associated reductions in morbidity and mortality, suggesting published employed strategies have been successful and safely implemented.

Transfusion rates in emergency general surgery: high but modifiable.

BACKGROUND: Transfusion of red blood cells (RBC) increases morbidity and mortality, and emergency general surgery (EGS) cases have increased risk for transfusion and complication given case complexity and patient acuity. Transfusion reduction strategies and blood-conservation technology have been developed to decrease transfusions. This study explores whether transfusion rates in EGS have decreased as these new strategies have been implemented. METHODS: This is a retrospective review of the American College of Surgeons' National Surgical Quality Improvement Program (ACS NSQIP) data from three academic medical centers. Operations performed by general surgeons on adults (aged ≥18 years) were selected. Data were analyzed from two periods: 2011-2013 and 2014-2016. Cases were grouped by the first four digits of the primary procedure Current Procedural Terminology code. Transfusion was defined as any RBC transfusion during or within 72 hours following the operation. Composite morbidity was defined as any NSQIP complication within 30 days following the operation. RESULTS: Overall general surgery transfusion rates decreased from 6.4% to 4.8% from period 1 to period 2 (emergent: 16.6%-11.5%; non-emergent 4.9%-3.7%; Fisher's exact p values <0.001). Among patients transfused, the number of units received decreased slightly (median 2 U (IQR 2-3) to median 2 U (IQR 1-3), Mann-Whitney U test p=0.005). Morbidity decreased (overall: 13.8%-12.3%, p=0.001; emergent: 26.3%-20.6%, p<0.001) while mortality did not change. DISCUSSION: Rates of RBC transfusion decreased in both emergent and non-emergent cases. Efforts to reduce transfusion may have been successful in the EGS population. Morbidity improved over the time periods while mortality was unchanged. LEVEL OF EVIDENCE: Level III.