A putative lipase affects Pseudomonas aeruginosa biofilm matrix production.

Pseudomonas aeruginosa is an opportunistic pathogen that is widely known for infecting patients with underlying conditions. This species often survives antibiotic therapy by forming biofilms, in which the cells produce a protective extracellular matrix. P. aeruginosa also produces virulence factors that enhance its ability to cause disease. One signaling pathway that influences virulence is the nitrogen-related phosphotransferase system (Nitro-PTS), which consists of an initial phosphotransferase, PtsP, a phosphocarrier, PtsO, and a terminal phosphate receptor, PtsN. The physiological role of the Nitro-PTS in P. aeruginosa is poorly understood. However, PtsN, when deprived of its upstream phosphotransfer proteins, has an antagonistic effect on biofilm formation. We thus conducted a transposon mutagenesis screen in an unphosphorylated-PtsN (i.e., ∆ptsP) background to identify downstream proteins with unacknowledged roles in PtsN-mediated biofilm suppression. We found an unstudied gene, PA14_04030, whose disruption restored biofilm production. This gene encodes a predicted phospholipase with signature alpha/beta hydrolase folds and a lipase signature motif with an active-site Ser residue. Hence, we renamed the gene bipL, for biofilm-impacting phospholipase. Deletion of bipL in a ∆ptsP background increased biofilm formation, supporting the idea that BipL is responsible for reducing biofilm formation in strains with unphosphorylated PtsN. Moreover, substituting the putative catalytic Ser for Ala phenocopied bipL deletion, indicating that this residue is important for the biofilm-suppressive activity of BipL in vivo. As our preliminary data suggest that BipL is a lipase, we performed lipidomics to detect changes in the lipid profile due to bipL deletion and found changes in some lipid species. IMPORTANCE Biofilm formation by bacteria occurs when cells secrete an extracellular matrix that holds them together and shields them from environmental insults. Biofilms of bacterial opportunistic human pathogens such as Pseudomonas aeruginosa pose a substantial challenge to clinical antimicrobial therapy. Hence, a more complete knowledge about the bacterial factors that influence and regulate production of the biofilm matrix is one key to formulate more effective therapeutic strategies. In this study, we screen for factors that are important for reducing biofilm matrix production in certain genetic backgrounds. We unexpectedly found a gene encoding a putative lipase enzyme and showed that its predicted catalytic site is important for its ability to reduce biofilm formation. Our findings suggest that lipase enzymes have previously uncharacterized functions in biofilm matrix regulation.

Defining patient-centered research priorities in pediatric dermatology.

BACKGROUND/OBJECTIVES: Patient and caregiver perspectives are critical in understanding dermatologic disease impact, presentation, and management in children. The Pediatric Dermatology Research Alliance (PeDRA) Patient Advisory Committee (PtAC), a group of patient representatives and parents of children with cutaneous disease, pursued a multistep, iterative, consensus-building process to identify comprehensive, high-priority research needs. METHODS: Building on discussions at the 2020 PeDRA Annual Conference, a research prioritization survey was developed and completed by PtAC members. Survey themes were aggregated and workshopped by the PtAC through a series of facilitated calls. Emerging priorities were refined in collaboration with additional PeDRA patient community members at the 2021 PeDRA Annual Conference. Subsequently, a final actionable list was agreed upon. RESULTS: Fourteen PtAC members (86.7% female) representing patients with alopecia areata, atopic dermatitis, vascular birthmarks, congenital melanocytic nevi, ectodermal dysplasias, epidermolysis bullosa, Gorlin syndrome, hidradenitis suppurativa, ichthyosis, pemphigus, psoriasis, Sturge-Weber syndrome, and pachyonychia congenita completed the survey. Following serial PtAC meetings, 60 research needs were identified from five domains: psychosocial challenges, health care navigation/disease management, causes/triggers, treatments to preserve or save life, and treatments to preserve or save quality of life. CONCLUSIONS: Many pediatric dermatology research priorities align across affected communities and may drive meaningful, patient-centric initiatives and investigations.

Lasers, Birthmarks, and Sturge-Weber Syndrome: A Pilot Survey.

BACKGROUND AND OBJECTIVES: There is limited or no data on the experience of patients with Sturge-Weber Syndrome (SWS) and/or their parents who seek out laser treatments for their port-wine birthmark (PWB). Our study aimed to develop a survey to understand patient perspectives on laser therapy and subsequent behaviors while focusing on three elements of the health belief model: perceived susceptibility, perceived benefits, and perceived barriers. STUDY DESIGN/MATERIALS AND METHODS: A 31 item survey was developed and sent to 650 members of the Sturge-Weber Foundation. The survey included questions regarding four domains: demographics, disease severity, laser experience, and perceptions and behaviors. Logistic regression models and bivariate analyses were conducted to analyze the results. RESULTS: Among the 123 respondents, earlier initiation of laser treatments was associated with greater birthmark satisfaction. Overall satisfaction increased up to 20 treatments and then leveled off. Color satisfaction increased up to 100 laser treatments; however, the flatness of the PWB was not associated with the number of laser treatments. The perceived benefits of lasers were not associated with the number of lifetime treatments or with spending. However, the perceived susceptibility was associated with greater spending on travel and medical expenses. CONCLUSION: The results of our survey provide insight into SWS patient experiences, beliefs, and behaviors regarding laser therapy. Further exploration of these variables may allow for the improvement of the care experience. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.