High rate of Clostridioides difficile colonization in patients admitted to intensive care: A prospective cohort study.

Here, we evaluated the frequency of C. difficile colonization and its impact on clinical outcomes in patients admitted to intensive care units in Brazil. From ninety-two patients screened 16 (17.3%) were colonized by C. difficile. Colonized patients had higher Simplified Acute Physiology Score III (SAPS III), however there was no association between C. difficile colonization with diarrhea or mortality. The C. difficile strains sequenced belonged to clade 1 and presented high vancomycin-resistant rates.

RT-qPCR half-reaction optimization for the detection of SARS-CoV-2.

INTRODUCTION: The main laboratory test for the diagnosis of coronavirus disease 2019 (COVID-19) is the reverse transcription real-time polymerase chain reaction (RT-qPCR). However, RT-qPCR is expensive because of the number of tests required. This study aimed to evaluate an alternative to the RT-qPCR approach for the detection of sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that is half of the total volume currently recommended by the US Centers for Disease Control and Prevention. METHODS: The analytical limit of detection (LoD) and the reaction efficiency using half volumes of the RT-qPCR assay were evaluated for the N1 and N2 regions using a synthetic control RNA. A panel of 76 SARS-CoV-2-positive and 26 SARS-CoV-2-negative clinical samples was evaluated to establish clinical sensitivity and specificity. RESULTS: The RT-qPCR assay efficiency was 105% for the half and standard reactions considering the N2 target and 84% (standard) and 101% (half) for N1. The RT-qPCR half-reaction LoD for N1 and N2 were 20 and 80 copies/µL, respectively. The clinical sensitivity and specificity were 100%. The half reaction presented a decrease of up to 5.5 cycle thresholds compared with standard RT-qPCR. CONCLUSIONS: The use of the RT-qPCR half-reaction proved feasible and economic for the detection of SARS-CoV-2 RNA.

SARS-CoV-2 nucleic acid shedding is variable for every person.

INTRODUCTION: Considering the persistent positivity on RT-qPCR tests, the results of SARS-CoV-2 were monitored to evaluate the viral RNA shedding period. METHODS: Between March and June 2020, the sequential results of 29 healthcare workers' were monitored using RT-qPCR. RESULTS: More than 50% of the individuals remained RT-qPCR positive after 14 days. Furthermore, this is the first study to describe positive RT-qPCR for SARS-CoV-2 in a healthcare worker with mild symptoms 95 days after the first positive test. CONCLUSIONS: Sequential RT-qPCR results were heterogeneous, and the viral RNA shedding period is unique for each person.

Rapid Detection of Carbapenemase Production Directly from Blood Culture by Colorimetric Methods: Evaluation in a Routine Microbiology Laboratory.

The aim of this study was to evaluate the two rapid colorimetric methods (CNPt-Direct and Blue-Carba) for the detection of carbapenemase production directly from blood culture in a routine microbiology laboratory. The methods were initially evaluated on spiked blood cultures with 61 carbapenemase-positive isolates. Afterwards, they were used in blood cultures (314 samples were evaluated) obtained from patients in a routine microbiology laboratory during a period of 6 months. The colorimetric methods were compared to the conventional culture of blood. The results of the spiked blood cultures indicated that both colorimetric methods presented positive results for the vast majority (95%) of the isolates harboring KPC, NDM, and IMP genes. However, the assay failed to detect many GES- and OXA-48-like-positive isolates (65% positive results). In the second part of the study, a total of 314 blood cultures from patients were evaluated, and 33 yielded Enterobacteriaceae isolates resistant to meropenem (30 isolates were positive for carbapenemases according to PCR). The colorimetric tests correctly detected 24 out of the 30 carbapenemase-positive isolates directly from the blood vial (80% positive results). Overall positive percent agreement and negative percent agreement were 80% and 100%, respectively. The colorimetric assays are simple and cost-effective methods that can be implemented in a routine microbiology laboratory, diminishing the time necessary to detect carbapenemase-producing isolates from 24 to 48 h to 3 to 5 h. Moreover, according to our results, the positive colorimetric test results do not need to be confirmed and can be immediately provided to the attending physician.