Seventeen Escherichia coli O157:H7 strains were treated with ultrahigh pressure at 500 MPa and 23 ؎ 2°C for 1 min. This treatment inactivated 0.6 to 3.4 log CFU/ml, depending on the strain. The diversity of these strains was confirmed by pulsed-field gel electrophoresis (PFGE) analysis, and there was no apparent association between PFGE banding patterns and pressure resistance. The pressure-resistant strain E. coli O157:H7 EC-88 (0.6-log decrease) and the pressure-sensitive strain ATCC 35150 (3.4-log decrease) were treated with a sublethal pressure (100 MPa for 15 min at 23 ؎ 2°C) and subjected to DNA microarray analysis using an E. coli K-12 antisense gene chip. High pressure affected the transcription of many genes involved in a variety of intracellular mechanisms of EC-88, including the stress response, the thiol-disulfide redox system, Fe-S cluster assembly, and spontaneous mutation. Twenty-four E. coli isogenic pairs with mutations in the genes regulated by the pressure treatment were treated with lethal pressures at 400 MPa and 23 ؎ 2°C for 5 min. The barotolerance of the mutants relative to that of the wild-type strains helped to explain the results obtained by DNA microarray analysis. This study is the first report to demonstrate that the expression of Fe-S cluster assembly proteins and the fumarate nitrate reductase regulator decreases the resistance to pressure, while sigma factor (RpoE), lipoprotein (NlpI), thioredoxin (TrxA), thioredoxin reductase (TrxB), a trehalose synthesis protein (OtsA), and a DNAbinding protein (Dps) promote barotolerance.

Objective: To compare physician-level versus practice-level primary care continuity and their association with expenditure and acute care utilization among Medicare beneficiaries and evaluate whether continuity of outpatient primary care at either/ both physician or/and practice level could be useful quality measures.Data Source: Medicare Fee-For-Service claims data for community dwelling beneficiaries without end-stage renal disease who were attributed to a national random sample of primary care practices billing Medicare (2011Medicare ( -2017.Study Design: Retrospective secondary data analysis at per Medicare beneficiary per year level. We used multivariable linear regression with practice-level fixed effects to estimate continuity of care score at physician versus practice level and their associations with outcomes.Data Collection/Extraction Method: We calculated clinician-and practice-level Bice-Boxerman continuity of care index scores, ranging from 0 to 1, using primary care outpatient claims. Medicare expenditures, hospital admissions, emergency department (ED) visits, and readmissions were obtained from the Medicare Beneficiary Summary File: Cost and Utilization Segment. Ambulatory care sensitive conditions (ACSC) were defined using diagnosis codes on inpatient claims.Principal Findings: We studied 2,359,400 beneficiaries who sought care from 13,926 physicians. Every 0.1 increase in physician continuity score was associated with a $151 reduction in expenditure per beneficiary per year (p < 0.01), and every 0.1 increase in practice continuity score was associated with $282 decrease (p < 0.01) per beneficiary per year. Both physician-and practice-level continuity were associated with lower Medicare expenditures among small, medium, and large practices.Both physician-and practice-level continuity were associated with lower probabilities of hospitalization, ED visit, admissions for ACSC, and readmission.Conclusions: Primary care continuity of care could serve as a potent value-based care quality metric. Physician-level continuity is a unique value center that cannot be supplanted by practice-level continuity.

Aims:  Investigating mechanisms of lethality enhancement when Escherichia coli O157:H7, and selected E. coli mutants, were exposed to tert‐butylhydroquinone (TBHQ) during ultra‐high pressure (UHP) treatment. Methods and Results:  Escherichia coli O157:H7 EDL‐933, and 14 E. coli K12 strains with mutations in selected genes, were treated with dimethyl sulfoxide solution of TBHQ (15–30 ppm), and processed with UHP (400 MPa, 23 ± 2°C for 5 min). Treatment of wild‐type E. coli strains with UHP alone inactivated 2·4–3·7 log CFU ml−1, whereas presence of TBHQ increased UHP lethality by 1·1–6·2 log CFU ml−1; TBHQ without pressure was minimally lethal (0–0·6 log reduction). Response of E. coli K12 mutants to these treatments suggests that iron–sulfur cluster‐containing proteins ([Fe–S]‐proteins), particularly those related to the sulfur mobilization (SUF system), nitrate metabolism, and intracellular redox potential, are critical to the UHP–TBHQ synergy against E. coli. Mutations in genes maintaining redox homeostasis and anaerobic metabolism were associated with UHP–TBHQ resistance. Conclusions:  The redox cycling activity of cellular [Fe–S]‐proteins may oxidize TBHQ, potentially leading to the generation of bactericidal reactive oxygen species. Significance and Impact of the Study:  A mechanism is proposed for the enhanced lethality of UHP by TBHQ against E. coli O157:H7. The results may benefit food processors using UHP–based preservation, and biologists interested in piezophilic micro‐organisms.

Undocumented farm workers' households were roughly half as likely to use Medicaid as documented households, and undocumented households' participation was especially responsive to the presence of children.