The spread of SARS-CoV-2 variants of concern (VOCs) is of great importance since genetic changes may increase transmissibility, disease severity and reduce vaccine effectiveness. Moreover, these changes may lead to failure of diagnostic measures. Therefore, variant-specific diagnostic methods are essential.
View Article and Find Full Text PDFFundamental key processes in viral infection cycles generally occur in distinct cellular sites where both viral and host factors accumulate and interact. These sites are usually termed viral replication organelles, or viral factories (VF). The generation of VF is accompanied by the synthesis of viral proteins and genomes and involves the reorganization of cellular structure.
View Article and Find Full Text PDFThe life-threatening disease tularemia is caused by Francisella tularensis, an intracellular Gram-negative bacterial pathogen. Due to the high mortality rates of the disease, as well as the low respiratory infectious dose, F. tularensis is categorized as a Tier 1 bioterror agent.
View Article and Find Full Text PDFThe current monkeypox virus global spread and lack of data regarding clinical specimens' infectivity call for examining virus infectivity, and whether this correlates with results from PCR, the available diagnostic tool. We show strong correlation between viral DNA amount in clinical specimens and virus infectivity toward BSC-1 cell line. Moreover, we define a PCR threshold value (Cq ≥ 35, ≤ 4,300 DNA copies/mL), corresponding to negative viral cultures, which may assist risk-assessment and decision-making regarding protective-measures and guidelines for patients with monkeypox.
View Article and Find Full Text PDFAs of July 2022, more than 16,000 laboratory-confirmed monkeypox (MPX) cases have been reported worldwide. Until recently, MPX was a rare viral disease seldom detected outside Africa. MPX virus (MPXV) belongs to the Orthopoxvirus (OPV) genus and is a genetically close relative of the Variola virus (the causative agent of smallpox).
View Article and Find Full Text PDFThe spike glycoprotein mediates virus binding to the host cells and is a key target for vaccines development. One SARS-CoV-2 vaccine is based on vesicular stomatitis virus (VSV), in which the native surface glycoprotein has been replaced by the SARS-CoV-2 spike protein (VSV-ΔG-spike). The titer of the virus is quantified by the plaque forming unit (PFU) assay, but there is no method for spike protein quantitation as an antigen in a VSV-based vaccine.
View Article and Find Full Text PDFPlague, caused by the human pathogen , is a severe and rapidly progressing lethal disease that has caused millions of deaths globally throughout human history and still presents a significant public health concern, mainly in developing countries. Owing to the possibility of its malicious use as a bio-threat agent, is classified as a tier-1 select agent. The prompt administration of an effective antimicrobial therapy, essential for a favorable patient prognosis, requires early pathogen detection, identification and isolation.
View Article and Find Full Text PDFSARS-CoV-2, the etiologic agent of the COVID-19 pandemic, emerged as the cause of a global crisis in 2019. Currently, the main method for identification of SARS-CoV-2 is a reverse transcription (RT)-PCR assay designed to detect viral RNA in oropharyngeal (OP) or nasopharyngeal (NP) samples. While the PCR assay is considered highly specific and sensitive, this method cannot determine the infectivity of the sample, which may assist in evaluation of virus transmissibility from patients and breaking transmission chains.
View Article and Find Full Text PDFRecently, numerous diagnostic approaches from different disciplines have been developed for SARS-CoV-2 diagnosis to monitor and control the COVID-19 pandemic. These include MS-based assays, which provide analytical information on viral proteins. However, their sensitivity is limited, estimated to be 5 × 10 PFU/ml in clinical samples.
View Article and Find Full Text PDFCoronavirus disease (COVID-19) is a contagious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This case report presents a patient who had difficulty eradicating the corona virus due to being treated with Rituximab, which depletes B lymphocyte cells and therefore disables the production of neutralizing antibodies. The combined use of external anti-viral agents like convalescent plasma, IVIG and Remdesivir successfully helped the patient's immune system to eradicate the virus without B-cell population recovery.
View Article and Find Full Text PDFPublic health experts emphasize the need for quick, point-of-care SARS-CoV-2 detection as an effective strategy for controlling virus spread. To this end, many "antigen" detection devices were developed and commercialized. These devices are mostly based on detecting SARS-CoV-2's nucleocapsid protein.
View Article and Find Full Text PDFSARS-CoV-2, the etiologic agent of the COVID-19 pandemic, emerged as the cause of a global crisis. Rapid and reliable clinical diagnosis is essential for effectively controlling transmission. The gold standard assay for SARS-CoV-2 identification is the highly sensitive real-time quantitative polymerase chain reaction (RT-qPCR); however, this assay depends on specialized reagents and may suffer from false results.
View Article and Find Full Text PDFRicin, a protein derived from the seeds of the castor bean plant (), is a highly lethal toxin that inhibits protein synthesis, resulting in cell death. The widespread availability of ricin, its ease of extraction and its extreme toxicity make it an ideal agent for bioterrorism and self-poisoning. Thus, a rapid, sensitive and reliable method for ricin identification in clinical samples is required for applying appropriate and timely medical intervention.
View Article and Find Full Text PDFThe genetic identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is based on viral RNA extraction prior to RT-qPCR assay. However, recent studies have supported the elimination of the extraction step. This study was performed to assess the necessity for the RNA extraction, by comparing the efficacy of RT-qPCR in several direct approaches versus the gold standard RNA extraction, in the detection of SARS-CoV-2 in laboratory samples, as well as in clinical oro-nasopharyngeal SARS-CoV-2 swabs.
View Article and Find Full Text PDFRicin, a plant-derived toxin extracted from the seeds of Ricinus communis (castor bean plant), is one of the most toxic proteins known. Ricin's high toxicity, widespread availability, and ease of its extraction make it a potential agent for bioterrorist attacks. Most ricin detection methods are based on immunoassays.
View Article and Find Full Text PDFRicin and abrin are ribosome-inactivating proteins leading to inhibition of protein synthesis and cell death. These toxins are considered some of the most potent and lethal toxins against which there is no available antidote. Digital holographic microscopy (DHM) is a time-lapse, label-free, and noninvasive imaging technique that can provide phase information on morphological features of cells.
View Article and Find Full Text PDFNontyphoidal (NTS) are important human enteric pathogens globally. Among the different serovars associated with human NTS disease, . Newport (a serogroup C-C) accounts for a measurable proportion of cases.
View Article and Find Full Text PDFThe early symptoms of tularemia and plague, which are caused by and infection, respectively, are common to other illnesses, resulting in a low index of suspicion among clinicians. Moreover, because these diseases can be treated only with antibiotics, rapid isolation of the bacteria and antibiotic susceptibility testing (AST) are preferable. Blood cultures of patients may serve as a source for bacteria isolation.
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