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Recent studies investigated the endurance of symptoms and occurrence of complications three months after SARS-CoV-2 infection. This study aims to examine the prevalence, variation, and severity of continual symptoms in the post-COVID-19 using a single-center questionnaire.The questionnaire was distributed among population in Saudi Arabia who recovered from COVID-19 between April 1, 2020 and December 31, 2021.A total of 744 participants completed the questionnaire, 318 (42.8%) recovered less than 3 months, 75 (10.1%) recovered 3-6 months, while 351 (47.2%) recovered more than 6 months. About half of the participants 353 (47.5%) had incessant symptoms and of those patients, more than half had two or more symptoms. Common symptoms included fatigue 189 (25.4%), headache 118 (15.9%), and myalgia 63 (8.5%). Of the participants, 189 (21.4%) experienced continual symptoms including anxiety in 98 (13.2%) and depression in 70 (9.5%).The current study showed a high proportion of individuals with long-COVID-19 symptoms. Thus, proper assessment of the individuals in the post-recovery period can guide the patients to the relevant clinics for rehabilitation. Moreover, there is a great importance to decrease COVID-19 infection, populations should be targeted to boost vaccine efficiency.

Contamination of aquatic systems with heavy metals (HM) is of great concern owing to their deleterious impact on living organism. The current research is focused on application of silica particles with new functionalized properties (magnetic silica; SiMag or Nanoporous silica; SiNPs) and their efficacy to mitigate lead (pb) toxicity in Nile tilapia. One thousand fingerlings were distributed: two control groups (negative; without pb toxicity (NC) positive (with pb toxicity) and other four groups received two silica sources (SiMag or SiNPs) with two levels (400 and 600 mg/kg diet) for 56 days then exposed to pb for 30 days. Before toxicity exposure, maximum growth, and most improved feed conversion ratio and biochemical parameters were noticed with higher SiMag or SiNPs levels. Serum antioxidant enzymes and their transcriptional levels in muscle and liver were boosted in groups received SiMag or SiNPs. After toxicity exposure, hematological and antioxidants biomarkers maintained at adequate levels in SiMag or SiNPs. Prominent reduction of residual pb in gills, liver, kidney, and muscle was observed in SiNPs then SiMag groups. Interestingly, the maximum down-regulation of P450, caspase-3 and HSP-70 and MT were observed in groups received 600 mg/kg diet of SiMag or SiNPs. The higher level of P53 in liver and gills was detected in PC, inversely reduced in SiMag or SiNPs. Severity of the histopathological alterations in examined organs greatly reduced in groups received SiMag or SiNPs, unlike it were induced in PC group. In conclusion, higher SiMag or SiNPs levels not only mitigate negatives impact of pb toxicity in fish but also ensure its safety for human consumption.

Two distinct type IV secretion systems (T4SSs) can be identified in certain Helicobacter pylori strains, encoded on mobile genetic elements termed tfs3 and tfs4. Although their function remains unknown, both have been implicated in clinical outcomes of H. pylori infection. Here we provide evidence that the Tfs3 T4SS is required for activity of the pro-inflammatory Ser/Thr kinase protein, CtkA, in a gastric epithelial cell infection model. Previously, purified recombinant CtkA protein has been shown to upregulate NF-kappaB signalling and induce TNF-alpha and IL-8 cytokine secretion from cultured macrophages suggesting that it may potentiate the H. pylori-mediated inflammatory response. In this study, we show that CtkA expressed from its native host, H. pylori has a similar capacity for stimulation of a pro-inflammatory response from gastric epithelial cells. CtkA interaction was found to be dependent upon a complement of tfs3 T4SS genes, but independent of the T4SSs encoded by either tfs4 or the cag pathogenicity island. Moreover, the availability of CtkA for host cell interaction was shown to be conditional upon the carboxyl-terminus of CtkA, encoding a putative conserved secretion signal common to other variably encoded Tfs3 proteins. Collectively, our observations indicate a role for the Tfs3 T4SS in CtkA-mediated pro-inflammatory signalling by H. pylori and identify CtkA as a likely Tfs3 T4SS secretion substrate.

Background: The complement of factors involved in mobilization of the Helicobacter pylori disease-associated tfs4 genomic island are presently unknown. Results: tfs4 encodes a VirD2-like relaxase with distinctive DNA binding and nicking activity. Conclusion: Tfs4 VirD2 probably initiates mobilization of tfs4 by specific interaction at a chromosomal transfer origin sequence. Significance: Tfs4 VirD2-mediated mobilization of tfs4 may increase pathogenic potential of H. pylori strains., Four different type IV secretion systems are variously represented in the genomes of different Helicobacter pylori strains. Two of these, encoded by tfs3 and tfs4 gene clusters are contained within self-transmissible genomic islands. Although chromosomal excision of tfs4 circular intermediates is reported to be dependent upon the function of a tfs4-encoded XerD tyrosine-like recombinase, other factors required for transfer to a recipient cell have not been demonstrated. Here, we characterize the functional activity of a putative tfs4-encoded VirD2-like relaxase protein. Tfs4 VirD2 was purified as a fusion to maltose-binding protein and demonstrated to bind and nick both supercoiled duplex DNA and oligonucleotides in vitro in a manner dependent upon the presence of Mg2+ but independently of any auxiliary proteins. Unusually, concentration-dependent nicking of duplex DNA appeared to require only transient protein-DNA interaction. Although phylogenetically distinct from established relaxase families, site-specific cleavage of oligonucleotides by Tfs4 VirD2 required the nick region sequence 5′-ATCCTG-3′ common to transfer origins (oriT) recognized by MOBP conjugative relaxases. Cleavage resulted in covalent attachment of MBP-VirD2 to the 5′-cleaved end, consistent with conventional relaxase activity. Identification of an oriT-like sequence upstream of tfs4 virD2 and demonstration of VirD2 protein-protein interaction with a putative VirC1 relaxosome component indicate that transfer initiation of the tfs4 genomic island is analogous to mechanisms underlying mobilization of other integrated mobile elements, such as integrating conjugative elements, requiring site-specific targeting of relaxase activity to a cognate oriT sequence.