Using PCR-Based Detection and Genotyping to Trace Streptococcus salivarius Meningitis Outbreak Strain to Oral Flora of Radiology Physician Assistant

We recently investigated three cases of bacterial meningitis that were reported from a midwestern radiology clinic where facemasks were not worn during spinal injection of contrast agent during myelography procedures. Using pulsed field gel electrophoresis we linked a case strain of S. salivarius to an oral specimen of a radiology physician assistant (RPA). We also used a real-time PCR assay to detect S. salivarius DNA within a culture-negative cerebrospinal fluid (CSF) specimen. Here we extend this investigation through using a nested PCR/sequencing strategy to link the culture-negative CSF specimen to the case strain. We also provide validation of the real-time PCR assay used, demonstrating that it is not solely specific for Streptococcus salivarius, but is also highly sensitive for detection of the closely related oral species Streptococcus vestibularis. Through using multilocus sequence typing and 16S rDNA sequencing we further strengthen the link between the CSF case isolate and the RPA carriage isolate. We also demonstrate that the newly characterized strains from this study are distinct from previously characterized S. salivarius strains associated with carriage and meningitis

Evaluation of viral co-infections among patients with community-associated Clostridioides difficile infection.

We assessed viral co-infections in 155 patients with community-associated Clostridioides difficile infection in five U.S. sites during December 2012-February 2013. Eighteen patients (12%) tested positive for norovirus (n = 10), adenovirus (n = 4), rotavirus (n = 3), or sapovirus (n = 1). Co-infected patients were more likely than non-co-infected patients to have nausea or vomiting (56% vs 31%; p = 0.04), suggesting that viral co-pathogens contributed to symptoms in some patients. There were no significant differences in prior healthcare or medication exposures or in CDI complications

Prescriber perceptions of fluoroquinolones, extended-spectrum cephalosporins, and Clostridioides difficile infection

Background: Fluoroquinolones (FQs) and extended-spectrum cephalosporins (ESCs) are associated with higher risk of Clostridioides difficile infection (CDI). Decreasing the unnecessary use of FQs and ESCs is a goal of antimicrobial stewardship. Understanding how prescribers perceive the risks and benefits of FQs and ESCs is needed.Methods: We conducted interviews with clinicians from 4 hospitals. Interviews elicited respondent perceptions about the risk of ESCs, FQs, and CDI. Interviews were audio recorded, transcribed, and analyzed using a flexible coding approach.Results: Interviews were conducted with 64 respondents (38 physicians, 7 nurses, 6 advance practice providers, and 13 pharmacists). ESCs and FQs were perceived to have many benefits, including infrequent dosing, breadth of coverage, and greater patient adherence after hospital discharge. Prescribers stated that it was easy to make decisions about these drugs, so they were especially appealing to use in the context of time pressures. They described having difficulty discontinuing these drugs when prescribed by others due to inertia and fear. Prescribers were skeptical about targeting specific drugs as a stewardship approach and felt that the risk of a negative outcome from under treatment of a suspected bacterial infection was a higher priority than the prevention of CDI.Conclusions: Prescribers in this study perceived many advantages to using ESCs and FQs, especially under conditions of time pressure and uncertainty. In making decisions about these drugs, prescribers balance risk and benefit, and they believed that the risk of CDI was acceptable in compared with the risk of undertreatment

Improved Phenotype-Based Definition for Identifying Carbapenemase Producers among Carbapenem-Resistant Enterobacteriaceae

Preventing transmission of carbapenemase-producing, carbapenem-resistant Enterobacteriaceae (CP-CRE) is a public health priority. A phenotype-based definition that reliably identifies CP-CRE while minimizing misclassification of non–CP-CRE could help prevention efforts. To assess possible definitions, we evaluated enterobacterial isolates that had been tested and deemed nonsusceptible to >1 carbapenem at US Emerging Infections Program sites. We determined the number of non-CP isolates that met (false positives) and CP isolates that did not meet (false negatives) the Centers for Disease Control and Prevention CRE definition in use during our study: 30% (94/312) of CRE had carbapenemase genes, and 21% (14/67) of Klebsiella pneumoniae carbapenemase–producing Klebsiella isolates had been misclassified as non-CP. A new definition requiring resistance to 1 carbapenem rarely missed CP strains, but 55% of results were false positive; adding the modified Hodge test to the definition decreased false positives to 12%. This definition should be considered for use in carbapenemase-producing CRE surveillance and prevention

Multilocus allele and 16S rRNA gene sequence designation depicting comparison of <i>S. salivarius</i> strain from meningitis patient to oral carriage isolates recovered from radiology physician assistant and technician.^a

a<p>The 8 housekeeping gene targets <i>glcK</i>, <i>ddlA</i>, <i>pepO</i>, <i>ilvC</i>, <i>thrS</i>, <i>pyrE</i>, <i>dnaE</i>, and <i>sodA</i> refer to the <i>S. salivarius</i>group MLST scheme described in reference 5 and the alleles correspond to the same ones listed in reference 5 except where in bold and italicized. The 7 remaining housekeeping gene targets (<i>rpoB</i>, <i>sodA2</i>, <i>pyk</i>, <i>ppaC</i>, <i>tuf</i>, <i>pfl</i>, <i>map</i>) refer to the viridans streptococcal MLST/speciating scheme available at <a href="http://viridans.emlsa.net/" target="_blank">http://viridans.emlsa.net/</a> (5). All bold/italicized designations correspond to sequences not found in the GenBank that were found in these isolates. GenBank accessions for the sequences corresponding to all of the underlined numbers are supplied in the Methods. The 8 following <i>S. salivarius</i> sequences have been previously documented by other investigators and are listed along with their GenBank accession numbers: <i>rpoB1</i>/GU556187, <i>sodA2-1</i>/AB200166, <i>ppaC1</i>/GU556189, <i>pyk2</i>/CP002888, <i>tuf1</i>/GU556190, <i>tuf2</i>/CP002888, 16S <i>rrnA2</i>/CP002888, and 16S <i>rrnA1</i>/GU175444.</p>b<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032169#s3" target="_blank">Results</a> shared between two isolates from case CSF.</p>c<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032169#s3" target="_blank">Results</a> shared between three carriage isolates (dorsal tongue and saliva).</p>d<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032169#s3" target="_blank">Results</a> shared between two carriage isolates (dorsal tongue and saliva).</p