RT-PCRs to detect SARS-CoV-2 RNA is key to manage the COVID-19 pandemic. We analyzed SARS-CoV-2 viral loads from 22′323 RT-PCR results according to samples types, gender, age, and health units. Viral ...load did not show any difference across age and appears to be a poor predictor of disease outcome. SARS-CoV-2 viral load showed similar high viral loads than the one observed for RSV and influenza B. The importance of viral load to predict contagiousness and to assess disease progression is discussed.
Abstract
Until recently, microbial identification in clinical diagnostic laboratories has mainly relied on conventional phenotypic and gene sequencing identification techniques. The development of ...matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) devices has revolutionized the routine identification of microorganisms in clinical microbiology laboratories by introducing an easy, rapid, high throughput, low-cost, and efficient identification technique. This technology has been adapted to the constraint of clinical diagnostic laboratories and has the potential to replace and/or complement conventional identification techniques for both bacterial and fungal strains. Using standardized procedures, the resolution of MALDI-TOF MS allows accurate identification at the species level of most Gram-positive and Gram-negative bacterial strains with the exception of a few difficult strains that require more attention and further development of the method. Similarly, the routine identification by MALDI-TOF MS of yeast isolates is reliable and much quicker than conventional techniques. Recent studies have shown that MALDI-TOF MS has also the potential to accurately identify filamentous fungi and dermatophytes, providing that specific standardized procedures are established for these microorganisms. Moreover, MALDI-TOF MS has been used successfully for microbial typing and identification at the subspecies level, demonstrating that this technology is a potential efficient tool for epidemiological studies and for taxonomical classification.
Use of MALDI-TOF mass spectrometry in routine microbial identification increased much during last years and it is time to summarize and review all available data, to help clinical microbiologist to use this quantum leap technology.
Chlamydia pneumoniae infection cases have usually accounted for <1.5% of community-acquired respiratory tract infections. Currently, Lausanne, Switzerland is experiencing a notable upsurge in cases, ...with 28 reported within a span of a few months. This upsurge in cases highlights the need for heightened awareness among clinicians.
Development of rapid and multiplexed diagnostic tools is a top priority to address the current epidemic problem of sexually transmitted diseases. Here we introduce a novel nanoplasmonic biosensor for ...simultaneous detection of the two most common bacterial infections: Chlamydia trachomatis and Neisseria gonorrhoeae. Our plasmonic microarray is composed of gold nanohole sensor arrays that exhibit the extraordinary optical transmission (EOT), providing highly sensitive analysis in a label-free configuration. The integration in a microfluidic system and the precise immobilization of specific antibodies on the individual sensor arrays allow for selective detection and quantification of the bacteria in real-time. We achieved outstanding sensitivities for direct immunoassay of urine samples, with a limit of detection of 300 colony forming units (CFU)/mL for C. trachomatis and 1500CFU/mL for N. gonorrhoeae. The multiplexing capability of our biosensor was demonstrated by analyzing different urine samples spiked with either C. trachomatis or N. gonorrhoeae, and also containing both bacteria. We could successfully detect, identify and quantify the levels of the two bacteria in a one-step assay, without the need for DNA extraction or amplification techniques. This work opens up new possibilities for the implementation of point-of-care biosensors that enable fast, simple and efficient diagnosis of sexually transmitted infections.
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•Plasmonic microarray for multiplexed diagnosis of sexually transmitted infections.•Plasmonic nanohole arrays enable highly sensitive and label-free biosensing.•Bacterial infections detected directly in urine, without amplification steps.•Different bacteria are identified in a one-step assay at physiological levels.
Atopic dermatitis (AD) has a well-established association with skin colonization or infection by Staphylococcus aureus, which can exacerbate the disease. However, a causal relationship between ...specific changes in skin colonization during the first years of life and AD development still remains unclear. In this prospective birth cohort study, we aimed to characterize the association between skin colonization and AD development in 149 white infants with or without a family history of atopy. We assessed infants clinically and collected axillary and antecubital fossa skin swabs for culture-based analysis at birth and at seven time points over the first 2 years of life. We found that at age 3 months, S. aureus was more prevalent on the skin of infants who developed AD later on. S. aureus prevalence was increased on infants’ skin at the time of AD onset and also 2 months before it, when compared with age-matched, unaffected infants. Furthermore, at AD onset, infants testing positive for S. aureus were younger than uncolonized subjects. In conclusion, our results suggest that specific changes in early-life skin colonization may actively contribute to clinical AD onset in infancy.
An ammonium chloride erythrocyte-lysing procedure was used to prepare a bacterial pellet from positive blood cultures for direct matrix-assisted laser desorption-ionization time of flight (MALDI-TOF) ...mass spectrometry analysis. Identification was obtained for 78.7% of the pellets tested. Moreover, 99% of the MALDI-TOF identifications were congruent at the species level when considering valid scores. This fast and accurate method is promising.
Insight in the biology of Chlamydia-related bacteria Bayramova, Firuza; Jacquier, Nicolas; Greub, Gilbert
Microbes and infection,
August-September 2018, 2018 Aug - Sep, 2018-08-00, 20180801, Letnik:
20, Številka:
7-8
Journal Article
Recenzirano
Odprti dostop
The Chlamydiales order is composed of obligate intracellular bacteria and includes the Chlamydiaceae family and several family-level lineages called Chlamydia-related bacteria. In this review we will ...highlight the conserved and distinct biological features between these two groups. We will show how a better characterization of Chlamydia-related bacteria may increase our understanding on the Chlamydiales order evolution, and may help identifying new therapeutic targets to treat chlamydial infections.
Administration of probiotics to premature newborns has been shown to prevent necrotizing enterocolitis and reduce all-cause mortality. In our hospital, we documented 2 cases of Bifidobacterium longum ...subspecies infantis bacteremia in newborns receiving probiotics. By comparative genomics, we confirmed that the strains isolated from each patient originated from the probiotics.
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