Clinical management of cUTI, cIAI, and HABP/VABP attributable to carbapenem-resistant Gram-negative infections in Spain

Introduction. Carbapenem-resistant Gram-negative (CRGN) infections are a major public health problem in Spain, often implicated in complicated, healthcare-associated infections that require the use of potentially toxic antibacterial agents of last resort. The objective of this study was to assess the clinical management of complicated infections caused by CRGN bacteria in Spanish hospitals. Methods. The study included: 1) a survey assessing the GN infection and antibacterial susceptibility profile in five participating Spanish hospitals and 2) a non-interventional, retrospective single cohort chart review of 100 patients with complicated urinary tract infection (cUTI), complicated intra-abdominal infection (cIAI), or hospital-acquired bacterial pneumonia/ventilator-associated bacterial pneumonia (HABP/ VABP) attributable to CRGN pathogens. Results. In the participating hospitals CRGN prevalence was 9.3% amongst complicated infections. In the retrospective cohort, 92% of infections were healthcare-associated, and Klebsiella pneumoniae and Pseudomonas aeruginosa were the most common pathogens. OXA was the most frequently detected carbapenemase type (71.4%). We found that carbap enems were frequently used to treat cUTI, cIAI, HABP/VABP caused by CRGN pathogens. Carbapenem use, particularly in combination with other agents, persisted after confirmation of carbapenem resistance. Clinical cure was 66.0%, mortality during hospitalization 35.0%, mortality at the time of chart review 62.0%, and 6-months-post-discharge readmission 47.7%. Conclusion. Our results reflect the high burden and un met needs associated with the management of complicated infections attributable to CRGN pathogens in Spain and highlight the urgent need for enhanced clinical management of these difficult-to-treat infections.Funding: Funding for this research was provided by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA

Investigating the role of the Mam2 C-terminal tail in the pheromone-signalling pathway of Schizosaccharomyces pombe

G protein-coupled receptors (GPCRs) allow cells to respond to extracellular stimuli and are involved in virtually all major physiological processes in eukaryotes. Consequently, aberrant GPCR signalling can lead to disease, making them attractive candidates for research and the development of pharmacological interventions. However, GPCR signalling responses in higher eukaryotes are complex, with the presence of multiple signalling pathways hindering the isolation and study of specific signalling components. The model organism, Schizosaccharomyces pombe, provides a simplified system with which to investigate GPCR signalling in the pheromoneresponse pathway. Pheromone stimulation in Sz. pombe causes the production of proteins necessary for the mating process, including the carboxypeptidase Sxa2. This study utilises Sz. pombe reporter strains in which sxa2 has been replaced with the bacterial reporter lacZ, thus enabling quantification of the level of signalling through the pheromoneresponse pathway. Using this system, the pheromone-responsive Mam2 receptor was investigated, with specific focus on the large intracellular C-terminal tail. Truncating Mam2 to remove the C-terminal tail altered signalling by increasing the level of ligand-independent signalling and decreasing the level of maximal signalling. Similar effects were observed when a regulator of G protein signalling, Rgs1, was removed from strains containing the full-length Mam2 receptor. This suggested a relationship between these two signalling components, which was confirmed through yeast 2-hybrid analysis. Using this approach, an 8-residue section of the Mam2 C-terminal tail was found to be necessary for a direct interaction with Rgs1. Further characterisation of the Mam2 tail revealed an additional role for this region in receptor sensitivity to pheromone stimulation. Mutational analysis implicated three serine residues in receptor sensitivity, suggesting that the C-terminal tail of Mam2 may contribute to receptor internalisation from the plasma membrane therefore enabling desensitisation to prolonged pheromone stimulation. Similar techniques applied to the study of Rgs1 revealed that two conserved DEP domains in the N-terminus of Rgs1 are important for the interaction with the Mam2 C-terminal tail. Fluorescent tagging of Rgs1 and subsequent microscopic analysis indicated that Rgs1 localises to endomembranous structures surrounding the nucleus, contrary to predictions made by mathematical models developed by this group, which suggest that Rgs1 requires plasma membrane-localisation in order to function. A better understanding of the action of Mam2 and Rgs1 in the Sz. pombe pheromone response can inform mathematical models and future studies involving the more complex mammalian signalling cascades.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Investigating the role of the Mam2 C-terminal tail in the pheromone-signalling pathway of Schizosaccharomyces pombe

G protein-coupled receptors (GPCRs) allow cells to respond to extracellular stimuli and are involved in virtually all major physiological processes in eukaryotes. Consequently, aberrant GPCR signalling can lead to disease, making them attractive candidates for research and the development of pharmacological interventions. However, GPCR signalling responses in higher eukaryotes are complex, with the presence of multiple signalling pathways hindering the isolation and study of specific signalling components. The model organism, Schizosaccharomyces pombe, provides a simplified system with which to investigate GPCR signalling in the pheromoneresponse pathway. Pheromone stimulation in Sz. pombe causes the production of proteins necessary for the mating process, including the carboxypeptidase Sxa2. This study utilises Sz. pombe reporter strains in which sxa2 has been replaced with the bacterial reporter lacZ, thus enabling quantification of the level of signalling through the pheromoneresponse pathway. Using this system, the pheromone-responsive Mam2 receptor was investigated, with specific focus on the large intracellular C-terminal tail. Truncating Mam2 to remove the C-terminal tail altered signalling by increasing the level of ligand-independent signalling and decreasing the level of maximal signalling. Similar effects were observed when a regulator of G protein signalling, Rgs1, was removed from strains containing the full-length Mam2 receptor. This suggested a relationship between these two signalling components, which was confirmed through yeast 2-hybrid analysis. Using this approach, an 8-residue section of the Mam2 C-terminal tail was found to be necessary for a direct interaction with Rgs1. Further characterisation of the Mam2 tail revealed an additional role for this region in receptor sensitivity to pheromone stimulation. Mutational analysis implicated three serine residues in receptor sensitivity, suggesting that the C-terminal tail of Mam2 may contribute to receptor internalisation from the plasma membrane therefore enabling desensitisation to prolonged pheromone stimulation. Similar techniques applied to the study of Rgs1 revealed that two conserved DEP domains in the N-terminus of Rgs1 are important for the interaction with the Mam2 C-terminal tail. Fluorescent tagging of Rgs1 and subsequent microscopic analysis indicated that Rgs1 localises to endomembranous structures surrounding the nucleus, contrary to predictions made by mathematical models developed by this group, which suggest that Rgs1 requires plasma membrane-localisation in order to function. A better understanding of the action of Mam2 and Rgs1 in the Sz. pombe pheromone response can inform mathematical models and future studies involving the more complex mammalian signalling cascades

Dose Escalation and Healthcare Resource Use among Ulcerative Colitis Patients Treated with Adalimumab in English Hospitals: An Analysis of Real-World Data.

OBJECTIVE:To describe the real-world use of adalimumab for maintenance treatment of ulcerative colitis (UC) and associated healthcare costs in English hospitals. DESIGN:Retrospective cohort study. SETTING:Analysis of NHS Hospital Episode Statistics linked with pharmacy dispensing data in English hospitals. PATIENTS:Adult UC patients receiving ≥240mg during adalimumab treatment induction, subsequently maintained on adalimumab. OUTCOMES:Frequency and pattern of adalimumab use and dose escalation during maintenance treatment and associated healthcare costs (prescriptions and hospital visits). RESULTS:191 UC patients completed adalimumab treatment induction. 83 (43.46%) dose escalated during maintenance treatment by ≥100% (equivalent to weekly dosing) (median time to dose escalation: 139 days). 56 patients (67.47%) subsequently de-escalated by ≥50% (median time to dose de-escalation: 21 days). Mean all-cause healthcare costs for all patients ≤12 months of index were £13,892. Dose escalators incurred greater mean healthcare costs than non-escalators ≤12 months of index (£14,596 vs. £13,351). Prescriptions accounted for 96.49% of UC-related healthcare costs (£11,090 of £11,494 in all patients). CONCLUSIONS:Within the cohort, 43.46% of UC patients escalated their adalimumab dose by ≥100% and incurred greater costs than non-escalators. The apparent underestimation of adalimumab dose escalation in previous studies may have resulted in underestimated costs in healthcare systems

Attributable burden in patients with carbapenem-nonsusceptible gram-negative respiratory infections.

OBJECTIVE:We aimed to describe the clinical and economic burden attributable to carbapenem-nonsusceptible (C-NS) respiratory infections. METHODS:This retrospective matched cohort study assessed clinical and economic outcomes of adult patients (aged ≥18 years) who were admitted to one of 78 acute care hospitals in the United States with nonduplicate C-NS and carbapenem-susceptible (C-S) isolates from a respiratory source. A subset analysis of patients with principal diagnosis codes denoting bacterial pneumonia or other diagnoses was also conducted. Isolates were classified as community- or hospital-onset based on collection time. A generalized linear mixed model method was used to estimate the attributable burden for mortality, 30-day readmission, length of stay (LOS), cost, and net gain/loss (payment minus cost) using propensity score-matched C-NS versus C-S cohorts. RESULTS:For C-NS cases, mortality (25.7%), LOS (29.4 days), and costs ($81,574) were highest in the other principal diagnosis, hospital-onset subgroup; readmissions (19.4$9522) were greatest in the bacterial pneumonia, hospital-onset subgroup. Mortality and readmissions were not significantly higher for C-NS cases in any propensity score-matched subgroup. Significant C-NS-attributable burden was found for both other principal diagnosis subgroups for LOS (hospital-onset: 3.7 days, P = 0.006; community-onset: 1.5 days, P<0.001) and cost (hospital-onset: $12,777, P<0.01; community-onset:$2681, P<0.001). CONCLUSIONS:Increased LOS and cost burden were observed in propensity score-matched patients with C-NS compared with C-S respiratory infections; the C-NS-attributable burden was significant only for patients with other principal diagnoses

Baseline patient characteristics.

<p>Baseline patient characteristics.</p

Application of inclusion criteria.

<p>Application of inclusion criteria.</p

Mean all-cause and UC-related healthcare costs within 12 months post-index.

<p>Mean all-cause and UC-related healthcare costs within 12 months post-index.</p

Study design.

<p>Study design.</p