Rachel L. Zapf

Purpose of Study: Hospital overcrowding and delays in discharge are serious issues in the modern health care landscape and can lead to poor patient outcomes and health care personnel (HCP) burnout. The goal of this project was to develop a collaborative forum where HCP representing the entire spectrum of the inpatient care team, including case management team members, could connect to discuss challenges and barriers to patient discharge. The following describes the development, implementation, and outcomes of the discharge SWAT (Solutions, Wins, Actions, and Tactics) team, which is a 30-min virtual daily meeting where discussion is primarily centered around challenges in discharging individual patients and addressing case manager needs. The primary aim of SWAT meetings is fostering a positive atmosphere to address barriers to discharge while prioritizing patient care and outcomes. Primary Practice Setting: This study was conducted in a 40-hospital academic health system in the United States. Methodology and Sample: SWAT meetings were first implemented at a representative flagship facility in a health system. HCP at this first facility were surveyed to assess satisfaction with SWAT meetings. SWAT meetings then were implemented at the majority of facilities in a 40-hospital academic health system. During SWAT implementation, average inpatient length of stay (LOS) and patient care transitions were monitored for participating and nonparticipating service lines. Results: Among surveyed HCP, the majority view SWAT meetings favorably and reported that it was a valuable use of their time and positively impacted their work in the patient discharge space. Nonprovider and case management staff in particular valued the SWAT meetings and found them beneficial. LOS remained stable for patients under the care of participating providers, despite the upheaval of the ongoing COVID-19 pandemic, and the research team also observed a positive impact of SWAT meetings on appropriate inpatient care transitions.

We analyzed efficacy of a centralized surveillance infection prevention (CSIP) program in a healthcare system on healthcare-associated infection (HAI) rates amid the coronavirus disease 2019 (COVID-19) pandemic. HAI rates were variable in CSIP and non-CSIP facilities. Central-line–associated bloodstream infection (CLABSI), C. difficile infection (CSI), and surgical-site infection (SSI) rates were negatively correlated with COVID-19 intensity in CSIP facilities.

Objective: To develop, implement, and evaluate the effectiveness of a unique centralized surveillance infection prevention (CSIP) program. Design: Observational quality improvement project. Setting: An integrated academic healthcare system. Intervention: The CSIP program comprises senior infection preventionists who are responsible for healthcare-associated infection (HAI) surveillance and reporting, allowing local infection preventionists (LIPs) a greater portion of their time to non-surveillance patient safety activities. Four CSIP team members accrued HAI responsibilities at 8 facilities. Methods: We evaluated the effectiveness of the CSIP program using 4 measures: recovery of LIP time, efficiency of surveillance activities by LIPs and CSIP staff, surveys characterizing LIP perception of their effectiveness in HAI reduction, and nursing leaders’ perception of LIP effectiveness. Results: The amount of time spent by LIP teams on HAI surveillance was highly variable, while CSIP time commitment and efficiency was steady. Post-CSIP implementation, 76.9% of LIPs agreed that they spend adequate time on inpatient units, compared to 15.4% pre-CSIP; LIPs also reported more time to allot to non-surveillance activities. Nursing leaders reported greater satisfaction with LIP involvement with HAI reduction practices. Conclusion: CSIP programs are a little-reported strategy to ease burden on LIPs with reallocation of HAI surveillance. The analyses presented here will aid health systems in anticipating the benefit of CSIP programs.

Objective: To evaluate the effectiveness of ultraviolet-C (UV-C) disinfection as an adjunct to standard chlorine-based disinfectant terminal room cleaning in reducing transmission of hospital-acquired multidrug-resistant organisms (MDROs) from a prior room occupant. Design: A retrospective cohort study was conducted to compare rates of MDRO transmission by UV-C status from January 1, 2016, through December 31, 2018. Setting: Acute-care, single-patient hospital rooms at 6 hospitals within an academic healthcare system in Pennsylvania. Methods: Transmission of hospital-acquired MDRO infection was assessed in patients subsequently assigned to a single-patient room of a source occupant with carriage of 1 or more MDROs on or during admission. Acquisition of 5 pathogens was compared between exposed patients in rooms with standard-of-care chlorine-based disinfectant terminal cleaning with or without adjunct UV-C disinfection. Logistic regression analysis was used to estimate the adjusted risk of pathogen transfer with adjunctive use of UV-C disinfection. Results: In total, 33,771 exposed patient admissions were evaluated; the source occupants carried 46,688 unique pathogens. Prior to the 33,771 patient admissions, 5,802 rooms (17.2%) were treated with adjunct UV-C disinfection. After adjustment for covariates, exposed patients in rooms treated with adjunct UV-C were at comparable risk of transfer of any pathogen (odds ratio, 1.06; 95% CI, 0.84–1.32; P = .64). Conclusion: Our analysis does not support the use of UV-C in addition to post-discharge cleaning with chlorine-based disinfectant to lower the risk of prior room occupant pathogen transfer.

Peptidyl-prolyl cis/trans isomerases (PPIases) are enzymes that catalyze the cis-to-trans isomerization around proline bonds, allowing proteins to fold into their correct confirmation. Previously, we identified two PPIase enzymes in Staphylococcus aureus (PpiB and PrsA) that are involved in the regulation of virulence determinants and have shown that PpiB contributes to S. aureus virulence in a murine abscess model of infection. Here, we further examine the role of these PPIases in S. aureus virulence and, in particular, their regulation of hemolytic toxins. Using murine abscess and systemic models of infection, we show that a ppiB mutant in a USA300 background is attenuated for virulence but that a prsA mutant is not. Deletion of the ppiB gene leads to decreased bacterial survival in macrophages and nasal epithelial cells, while there is no significant difference when prsA is deleted. Analysis of culture supernatants reveals that a ppiB mutant strain has reduced levels of the phenol-soluble modulins and that both ppiB and prsA mutants have reduced alpha-toxin activity. Finally, we perform immunoprecipitation to identify cellular targets of PpiB and PrsA. Results suggest a novel role for PpiB in S. aureus protein secretion. Collectively, our results demonstrate that PpiB and PrsA influence S. aureus toxins via distinct mechanisms, and that PpiB but not PrsA contributes to disease.

Numerous factors have, to date, been identified as playing a role in the regulation of Agr activity in Staphylococcus aureus, including transcription factors, antisense RNAs, and host elements. Herein we investigated the product of SAUSA300_1984 (termed MroQ), a transmembrane Abi-domain/M79 protease-family protein, as a novel effector of this system. Using a USA300 mroQ mutant, we observed a drastic reduction in proteolysis, hemolysis, and pigmentation that was fully complementable. This appears to result from diminished agr activity, as transcriptional analysis revealed significant decreases in expression of both RNAII and RNAIII in the mroQ mutant. Such effects appear to be direct, rather than indirect, as known agr effectors demonstrated limited alterations in their activity upon mroQ disruption. A comparison of RNA sequencing data sets for both mroQ and agr mutants revealed a profound overlap in their regulomes, with the majority of factors affected being known virulence determinants. Importantly, the preponderance of alterations in expression were more striking in the agr mutant, indicating that MroQ is necessary, but not sufficient, for Agr function. Mechanism profiling revealed that putative residues for metalloprotease activity within MroQ are required for its Agr-controlling effect; however, this was not wielded at the level of AgrD processing. Virulence assessment demonstrated that both mroQ and agr mutants exhibited increased formation of renal abscesses but decreased skin abscess formation alongside diminished dermonecrosis. Collectively, we present the characterization of a novel agr effector in S. aureus which would appear to be a direct regulator, potentially functioning via interaction with the AgrC histidine kinase.

Small RNAs (sRNAs) remain an understudied class of regulatory molecules in bacteria in general and in Gram-positive bacteria in particular. In the major human pathogen Staphylococcus aureus, hundreds of sRNAs have been identified; however, only a few have been characterized in detail. In this study, we investigate the role of the sRNA Teg41 in S. aureus virulence. We demonstrate that Teg41, an sRNA divergently transcribed from the locus that encodes the cytolytic alpha phenol-soluble modulin (αPSM) peptides, plays a critical role in αPSM production. Overproduction of Teg41 leads to an increase in αPSM levels and a corresponding increase in hemolytic activity from S. aureus cells and cell-free culture supernatants. To identify regions of Teg41 important for its function, we performed an in silico RNA-RNA interaction analysis which predicted an interaction between the 3′ end of Teg41 and the αPSM transcript. Deleting a 24-nucleotide region from the S. aureus genome, corresponding to the 3′ end of Teg41, led to a 10-fold reduction in αPSM-dependent hemolytic activity and attenuation of virulence in a murine abscess model of infection. Restoration of hemolytic activity in the Teg41Δ3′ strain was possible by expressing full-length Teg41 in trans. Restoration of hemolytic activity was also possible by expressing the 3′ end of Teg41, suggesting that this region of Teg41 is necessary and sufficient for αPSM-dependent hemolysis. Our results show that Teg41 is positively influencing αPSM production, demonstrating for the first time regulation of the αPSM peptides by an sRNA in S. aureus. IMPORTANCE The alpha phenol-soluble modulins (αPSMs) are among the most potent toxins produced by Staphylococcus aureus. Their biological role during infection has been studied in detail; however, the way they are produced by the bacterial cell is not well understood. In this work, we identify a small RNA molecule called Teg41 that plays an important role in αPSM production by S. aureus. Teg41 positively influences αPSM production. The importance of Teg41 is highlighted by the fact that a strain containing a deletion in the 3′ end of Teg41 produces significantly less αPSMs and is attenuated for virulence in a mouse abscess model of infection. As the search for new therapeutic strategies to combat S. aureus infection proceeds, Teg41 may represent a novel target.

Numerous factors have to date been identified as playing a role in the regulation of Agr activity in S. aureus , including transcription factors, antisense RNAs, and host elements. Herein we investigate the product of SAUSA300_1984 (termed MroQ), a transmembrane Abi-domain/M79 protease-family protein, as a novel effector of this system. Using a USA300 mroQ mutant we observed a drastic reduction in proteolysis, hemolysis and pigmentation that was fully complementable. This appears to result from diminished agr activity, as transcriptional analysis revealed significant decreases in expression of both RNAII and RNAIII in the mroQ mutant. Such effects appear to be direct, rather than indirect, as known agr effectors demonstrated limited alterations in their activity upon mroQ disruption. A comparison of RNA-sequencing datasets for both mroQ and agr mutants reveal a profound overlap in their regulomes, with the majority of factors affected being known virulence determinants. Importantly, the preponderance of alterations in expression were more striking in the agr mutant, indicating that MroQ is necessary, but not sufficient, for Agr function. Mechanism profiling revealed that putative residues for metalloprotease activity within MroQ are required for its Agr controlling effect, however this is not wielded at the level of AgrD processing. Virulence assessment demonstrated that mroQ and agr mutants both exhibited increased formation of renal abscesses, but decreased skin abscess formation, alongside diminished dermonecrosis. Collectively, we present the characterization of a novel agr effector in S. aureus , which would appear to be a direct regulator, potentially functioning via interaction with the AgrC histidine kinase.