Loss of Smell and Taste Among Healthcare Personnel Screened for Coronavirus 2019.

Among 283 symptomatic healthcare personnel (HCP) tested for SARS-CoV-2, 51 (18%) were positive. Among those 51 HCP, self reported loss of smell and taste were present in 51% and 52.9%, respectively, with either present in 60.8%. These symptoms had high specificity (93% each, 96% for either) for a positive SARS-CoV-2 test.

Rapid laboratory diagnosis for respiratory infectious diseases by using MALDI-TOF mass spectrometry.

It is still challenging to prevent and treat respiratory infectious diseases. One critical step in the successful treatment of respiratory infections is rapid diagnosis by identifying the causative microorganisms in a timely fashion. However, traditional methods for identification of causative agents could not satisfy the need for rapid and accurate testing due to the limitations of technology-used. In recent years, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) has been validated and used for rapid identification of microorganism and for potential discovery of diseases associated biomarkers. We reviewed recent advances of MALDI-TOF-MS as the laboratory diagnostic tool for the rapid laboratory diagnosis of microorganisms associated with respiratory infectious diseases, with the focus on rapid identification of pathogenic bacteria and molecular markers discovery using MALDI-TOF-MS. With the advanced technologies such as MALDI-TOF, early and targeted therapies based on rapid identification of pathogens and could lead to quick and effective treatment of respiratory infections and better patient management.

Querying automated antibiotic susceptibility testing instruments: a novel population-based active surveillance method for multidrug-resistant gram-negative bacilli.

OBJECTIVE: To describe the implementation of a population-based surveillance system for multidrug-resistant gram-negative bacilli (MDR-GNB). DESIGN: Population-based active surveillance by the Georgia Emerging Infections Program. SETTING: Metropolitan Atlanta, starting November 2010. PATIENTS: Residents with MDR-GNB isolated from urine or a normally sterile site culture. METHODS: Surveillance was implemented in 3 phases: (1) surveying laboratory antibiotic susceptibility testing practices, (2) piloting surveillance to estimate the proportion of GNB that were MDR, and (3) maintaining ongoing active surveillance for carbapenem-nonsusceptible Enterobacteriaceae and Acinetobacter baumannii using the 2010 Clinical and Laboratory Standards Institute (CLSI) breakpoints. Pilot surveillance required developing and installing queries for GNB on the 3 types of automated testing instruments (ATIs), such as MicroScan, in Atlanta's clinical laboratories. Ongoing surveillance included establishing a process to extract data from ATIs consistently, review charts, manage data, and provide feedback to laboratories. RESULTS: Output from laboratory information systems typically used for surveillance would not reliably capture the CLSI breakpoints, but queries developed for the 3 ATIs did. In November 2010, 0.9% of Enterobacteriaceae isolates and 35.7% of A. baumannii isolates from 21 laboratories were carbapenem nonsusceptible. Over a 5-month period, 82 Enterobacteriaceae and 59 A. baumannii were identified as carbapenem nonsusceptible. CONCLUSIONS: Directly querying ATIs, a novel method of active surveillance for MDR-GNB, proved to be a reliable, sustainable, and accurate method that required moderate initial investment and modest maintenance. Ongoing surveillance is critical to assess the burden of and changes in MDR-GNB to inform prevention efforts.

Same day identification and full panel antimicrobial susceptibility testing of bacteria from positive blood culture bottles made possible by a combined lysis-filtration method with MALDI-TOF VITEK mass spectrometry and the VITEK2 system.

Rapid identification and antimicrobial susceptibility testing of microorganisms causing bloodstream infections or sepsis have the potential to improve patient care. This proof-of-principle study evaluates the Lysis-Filtration Method for identification as well as antimicrobial susceptibility testing of bacteria directly from positive blood culture bottles in a clinical setting. A total of 100 non-duplicated positive blood cultures were tested and 1012 microorganism-antimicrobial combinations were assessed. An aliquot of non-charcoal blood culture broth was incubated with lysis buffer briefly before being filtered and washed. Microorganisms recovered from the filter membrane were first identified by using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight VITEK® Mass Spectrometry (VITEK MS). After quick identification from VITEK MS, filtered microorganisms were inoculated to VITEK®2 system for full panel antimicrobial susceptibility testing analysis. Of 100 bottles tested, the VITEK MS resulted in 94.0% correct organism identification to the species level. Compared to the conventional antimicrobial susceptibility testing methods, direct antimicrobial susceptibility testing from VITEK®2 resulted in 93.5% (946/1012) category agreement of antimicrobials tested, with 3.6% (36/1012) minor error, 1.7% (7/1012) major error, and 1.3% (13/1012) very major error of antimicrobials. The average time to identification and antimicrobial susceptibility testing was 11.4 hours by using the Lysis-Filtration method for both VITEK MS and VITEK®2 compared to 56.3 hours by using conventional methods (p<0.00001). Thus, the same-day results of microorganism identification and antimicrobial susceptibility testing directly from positive blood culture can be achieved and can be used for appropriate antibiotic therapy and antibiotic stewardship.

Comparison of heat inactivation and cell disruption protocols for identification of mycobacteria from solid culture media by use of vitek matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Two novel protocols for inactivation and extraction were developed and used to identify 107 Mycobacterium clinical isolates, including Mycobacterium tuberculosis complex, from solid cultures using Vitek matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. The protocol using heat inactivation with sonication and cell disruption with glass beads resulted in 82.2% and 88.8% species and genus level identifications, respectively.

Rapid identification of bacteria and yeasts from positive-blood-culture bottles by using a lysis-filtration method and matrix-assisted laser desorption ionization-time of flight mass spectrum analysis with the SARAMIS database.

Rapid identification of microorganisms causing bloodstream infections directly from a positive blood culture would decrease the time to directed antimicrobial therapy and greatly improve patient care. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) is a fast and reliable method for identifying microorganisms from positive culture. This study evaluates the performance of a novel filtration-based method for processing positive-blood-culture broth for immediate identification of microorganisms by MALDI-TOF with a Vitek MS research-use-only system (VMS). BacT/Alert non-charcoal-based blood culture bottles that were flagged positive by the BacT/Alert 3D system were included. An aliquot of positive-blood-culture broth was incubated with lysis buffer for 2 to 4 min at room temperature, the resulting lysate was filtered through a membrane, and harvested microorganisms were identified by VMS. Of the 259 bottles included in the study, VMS identified the organisms in 189 (73%) cultures to the species level and 51 (19.7%) gave no identification (ID), while 6 (2.3%) gave identifications that were considered incorrect. Among 131 monomicrobic isolates from positive-blood-culture bottles with one spot having a score of 99.9%, the IDs for 131 (100%) were correct to the species level. In 202 bottles where VMS was able to generate an ID, the IDs for 189 (93.6%) were correct to the species level, whereas the IDs provided for 7 isolates (3.5%) were incorrect. In conclusion, this method does not require centrifugation and produces a clean spectrum for VMS analysis in less than 15 min. This study demonstrates the effectiveness of the new lysis-filtration method for identifying microorganisms directly from positive-blood-culture bottles in a clinical setting.

Probability of negative mycobacterium tuberculosis complex cultures based on time to detection of positive cultures: a multicenter evaluation of commercial-broth-based culture systems.

We conducted a multicenter study to determine whether Mycobacterium tuberculosis complex (MTBC) cultures in automated broth-based systems could reliably be considered negative sooner than 6 weeks. Laboratory sites used Bactec MGIT or BacT/Alert and tracked results of time to detection of all mycobacteria (TTD-all, n = 1547) and of MTBC (TTD-MTBC, n = 466) over 6-month periods from primarily (93%) respiratory specimens. Cumulative percentages by day detected and median TTD of initial and follow-up specimens were analyzed. The median TTD-MTBC for MGIT (n = 6 sites) was 14 days. For laboratories using standard processing procedures, 100% of MTBC were detected from initial and follow-up specimens in 28 and 35 days, respectively, and no yield of MTBC on solid or MGIT liquid media was observed after 5 weeks. The median TTD-MTBC for BacT/Alert (n = 3 sites) was 18 days, with 95% and 100% detected within 37 and 42 days, respectively. Analysis of TTD of positive MTBC cultures in broth can predict the probability of culture negativity at defined time points. Receipt of interim negative reports earlier than 6 weeks could assist clinicians in considering alternative diagnoses and could alter the timing and prioritization of public health interventions. Laboratories should analyze their own TTD data to inform protocol decisions. Laboratories using MGIT could issue reports of no growth of MTBC on initial specimens as early as 4 weeks and for patients undergoing treatment as early as 5 weeks postinoculation.

Multilaboratory evaluation of real-time PCR tests for hepatitis B virus DNA quantification.

The performance characteristics of four different assays for hepatitis B virus (HBV) quantification were assessed: the Abbott RealTime HBV IUO, the Roche Cobas AmpliPrep/Cobas TaqMan HBV test, the Roche Cobas TaqMan HBV test with HighPure system, and the Qiagen artus HBV TM ASR. Limit of detection (LOD), linear range, reproducibility, and agreement were determined using a serially diluted plasma sample from a single chronically infected subject. Each assay was tested by at least three laboratories. The LOD of the RealTime and two TaqMan assays was approximately 1.0 log(10) IU/ml; for artus HBV (which used the lowest volume of extracted DNA), it was approximately 1.5 log(10) IU/ml. The linear range spanned 1.0 to at least 7.0 log(10) IU/ml for all assays. Median values were consistently lowest for artus HBV and highest for Cobas AmpliPrep/Cobas TaqMan HBV. Assays incorporating automated nucleic acid extraction were the most reproducible; however, the overall variability was minor since the standard deviations for the means of all tested concentrations were ≤0.32 log(10) IU/ml for all assays. False-positive results were observed with all assays; the highest rates occurred with tests using manual nucleic acid extraction. The performance characteristics of these assays suggest that they are useful for management and therapeutic monitoring of chronic HBV infection.

In vitro activity of tigecycline and comparators on Acinetobacter spp. isolates collected from patients with bacteremia and MIC change during the Tigecycline Evaluation and Surveillance Trial, 2004 to 2008.

The Tigecycline Evaluation and Surveillance Trial is a global surveillance study established in 2004 to monitor the activity of tigecycline, a new glycylcycline, and several comparators against an array of important Gram-positive and Gram-negative pathogens. In this study, we examined 1591 isolates of Acinetobacter from blood samples collected from 352 centers globally between 2004 and 2008. Tigecycline showed an MIC(90) (1 microg/mL) globally, with a maximum regional value of 4 microg/mL (Middle East) reported. Antimicrobial susceptibility was notably higher among nonintensive care unit (non-ICU) isolates than isolates collected from ICUs. Carbapenem-resistant Acinetobacter were more prevalent in the Middle East, Latin America, and Asia/Pacific rim than in Europe or North America. Tigecycline creep was noted between 2004 and 2007, corresponding closely to changes in MIC(90).