Burnham, Carey‐Ann D.

Antibiotic resistance, particularly to carbapenems, is of increasing concern in Bacteroides fragilis . Carbapenem resistance in B. fragilis is most often mediated by the activation of chromosomally encoded metallo-β-lactamase cfiA by the presence of an upstream insertion sequence (IS).

Staphylococcus argenteus is a newly described species, formerly known as S. aureus clonal complex 75 (CC75). Here, we describe the largest collection of S. argenteus isolates in North America, highlighting identification challenges.

Abstract Background Current American College of Gastroenterology (ACG) guidelines suggest that Helicobacter pylori serologic testing may be helpful to rule out H. pylori in areas with low disease prevalence. However, even in low prevalence regions, the positive predictive value of a positive serologic result remains low. Additionally, both the ACG and the American Gastroenterological Association recommend that this noninvasive testing be avoided entirely for patients 55 years and older. Methods The objective of this multicenter retrospective study was to assess H. pylori seroprevalence rates among symptomatic patients and serologic test utilization at the local, state, and national level. Submitted specimens were presumed to be collected from patients with upper gastrointestinal symptoms suspicious for an H. pylori etiology. Results for H. pylori IgG serologic tests performed between 2005 and 2014 were collected from 5 medical centers. Data were evaluated in the context of professional practice guidelines, with a focus on patients ages 55 years and older. Results Nationwide seropositivity among symptomatic individuals is approximately 25%, and 4 of 5 centers reported decreasing seropositivity rates over this 10-year period. State-specific seropositivity among symptomatic patients ranged from 12.4% in the state of Washington to 33.9% in Mississippi. Conclusions We demonstrate that for 48 states >25% of all H. pylori serologic testing was performed in individuals ≥55 years. Despite recommendations to avoid serologic evaluation for H. pylori infection, this study indicates that serology continues to be used at high rates across age-groups.