A general approach for evaluating of the coverage, resolution, and representation of streamflow monitoring networks.

Streamflow monitoring networks provide information for a wide range of public interests in river and streams. A general approach to evaluate monitoring for different interests is developed to support network planning and design. The approach defines three theoretically distinct information metrics (coverage, resolution, and representation) based on the spatial distribution of a variable of interest. Coverage is the fraction of information that a network can provide about a variable when some areas are not monitored. Resolution is the information available from the network relative to the maximum information possible given the number of sites in the network. Representation is the information that a network provides about a benchmark distribution of a variable. Information is defined using Shannon entropy where the spatial discretization of a variable among spatial elements of a landscape or sites in a network indicates the uncertainty in the spatial distribution of the variable. This approach supports the design of networks for monitoring of variables with heterogeneous spatial distributions ("hot spots" and patches) that might otherwise be unmonitored because they occupy insignificant portions of the landscape. Areas where monitoring will maintain or improve the metrics serve as objective priorities for public interests in network design. The approach is demonstrated for the streamflow monitoring network operated by the United States Geological Survey during water year 2020 indicating gaps in the coverage of coastal rivers and the resolution of low flows.

Neutropenia Associated with Long-Term Ceftaroline Use.

Ceftaroline is a fifth-generation cephalosporin with potent antimicrobial activity against Gram-positive and Gram-negative pathogens. Neutropenia is a rare serious adverse event for the class of cephalosporins; however, we observed several cases of severe neutropenia in our outpatient infectious disease practice believed to be associated with ceftaroline use. The aim of this study was to determine the incidence of neutropenia among patients receiving ceftaroline therapy for more than 7 days. We conducted a retrospective cohort analysis of patients admitted to an 800-bed regional medical center between June 2012 and December 2014 who received ceftaroline for more than 7 days to assess the incidence of developing clinically significant neutropenia. Demographic and patient care data points as well as underlying admitting and chronic diagnoses were retrospectively collected from the medical record. Clinically significant neutropenia was defined as an absolute neutrophil count (ANC) less than 1,500 cells/mm(3). Analysis was performed to determine the incidence, severity, and outcome of neutropenia following ceftaroline administration. A total of 39 patients were included in the cohort. The median duration of therapy was 27 days. Seven patients (18%) developed neutropenia while on ceftaroline therapy. Four (10%) of the neutropenic patients had an ANC of <500 cells/mm(3). The median first neutropenic day was day 17, with the median ANC nadir of 432 cells/mm(3) on day 24. We determined that extended ceftaroline infusion is associated with the development of neutropenia. We recommend obtaining a complete blood count (CBC) with differential at the onset of therapy and weekly thereafter. Should the ANC fall below 2,500 cells/mm(3), then twice-weekly CBCs should be monitored for the duration of ceftaroline therapy, and therapy should be discontinued if the ANC falls to 1,500 cells/mm(3) or less.

Characterization of small-colony-variant Stenotrophomonas maltophilia isolated from the sputum specimens of five patients with cystic fibrosis.

Cystic fibrosis (CF) patients are predisposed to chronic respiratory infection by nonfermentative gram-negative bacilli, including Stenotrophomonas maltophilia. S. maltophilia is highly resistant to most antibiotics, with the exception of sulfamethoxazole-trimethoprim (SXT). SXT-resistant S. maltophilia has been reported, but the mechanism of resistance is not well defined. Repeated findings of suspected small-colony-variant (SCV) S. maltophilia isolates from the sputa of five CF patients were confirmed by partial 16S rRNA gene sequencing. The SCV S. maltophilia isolates were the only S. maltophilia isolates in these cultures, and none were clonally related. DNA fingerprint analysis confirmed that once established, the SCV S. maltophilia strains persisted. Nutritional studies of SCV S. maltophilia have suggested auxotrophy in hemin, methionine, and thymidine associated with resistance to multiple antibiotics, including SXT. The phenotypic switch from wild-type to SCV S. maltophilia was reproducible in vitro by exposure to SXT, suggesting that prolonged exposure to antibiotics may select for both the SCV S. maltophilia phenotype and SXT resistance by interference with the dihydrofolate reductase pathway. Recovery of SCV S. maltophilia from the sputum of CF patients has implications for both laboratory testing and patient management.