Detection of A2142G, A2142C and A2143G clarithromycin mutations in Helicobacter pylori in Alexandria University Pediatric Hospital

Background: Helicobacter pylori (H. pylori)colonizes the stomach and affect almost 50% of the world’s population. Clarithromycin is considered a cornerstone for H. pylori treatment. Emergence of clarithromycin resistance (CLR-R) has played a major role in failure of H. pylori eradication both in adults and children.  Clarithromycin resistance is mostly due to mutations in 23S rRNA gene: A2142G, A2142C, and A2143G. The aim of the current study is to determine the prevalence of CLR-R among H. pylori infected children with prior clarithromycin treatment. Materials and Methods: Multiple endoscopic gastric biopsies were collected from 50 H. pylori infected children after cessation of clarithromycin-based treatment. Samples were subjected to histopathological examinations, rapid urease test (RUT) and simultaneous molecular detection of H. pylori infection as well as CLR-R by multiplex Real-Time polymerase chain reaction (PCR). Results: Histopathological examinations and RUT revealed H. pylori in 74% and 92% of samples respectively. Molecular detection of CLR-R showed that 62.5% positive H. pylori cases were not harboring any of the tested mutations, while 25% harbored 2143A-G single mutation. Double mutations (2142A-C and 2143A-G) were detected in only 4 cases. Statistical significant correlation existed between both RUT and PCR results as well as between histopathological findings and PCR test results. Conclusions: A combination of histopathogy, RUT and multiplex PCR procedures offers a real benefit in the simultaneous diagnosis of H. pylori infection along with clarithromycin resistance status. Other mechanisms of clarithromycin resistance need to be investigated to explain treatment failure in absence of the previously detected mutations

A computational approach identifies two regions of Hepatitis C Virus E1 protein as interacting domains involved in viral fusion process

<p>Abstract</p> <p>Background</p> <p>The E1 protein of Hepatitis C Virus (HCV) can be dissected into two distinct hydrophobic regions: a central domain containing an hypothetical fusion peptide (FP), and a C-terminal domain (CT) comprising two segments, a pre-anchor and a trans-membrane (TM) region. In the currently accepted model of the viral fusion process, the FP and the TM regions are considered to be closely juxtaposed in the post-fusion structure and their physical interaction cannot be excluded. In the present study, we took advantage of the natural sequence variability present among HCV strains to test, by purely sequence-based computational tools, the hypothesis that in this virus the fusion process involves the physical interaction of the FP and CT regions of E1.</p> <p>Results</p> <p>Two computational approaches were applied. The first one is based on the co-evolution paradigm of interacting peptides and consequently on the correlation between the distance matrices generated by the sequence alignment method applied to FP and CT primary structures, respectively. In spite of the relatively low random genetic drift between genotypes, co-evolution analysis of sequences from five HCV genotypes revealed a greater correlation between the FP and CT domains than respect to a control HCV sequence from Core protein, so giving a clear, albeit still inconclusive, support to the physical interaction hypothesis.</p> <p>The second approach relies upon a non-linear signal analysis method widely used in protein science called Recurrence Quantification Analysis (RQA). This method allows for a direct comparison of domains for the presence of common hydrophobicity patterns, on which the physical interaction is based upon. RQA greatly strengthened the reliability of the hypothesis by the scoring of a lot of cross-recurrences between FP and CT peptides hydrophobicity patterning largely outnumbering chance expectations and pointing to putative interaction sites. Intriguingly, mutations in the CT region of E1, reducing the fusion process <it>in vitro</it>, strongly reduced the amount of cross-recurrence further supporting interaction between this region and FP.</p> <p>Conclusion</p> <p>Our results support a fusion model for HCV in which the FP and the C-terminal region of E1 are juxtaposed and interact in the post-fusion structure. These findings have general implications for viruses, as any visualization of the post-fusion FP-TM complex has been precluded by the impossibility to obtain crystallised viral fusion proteins containing the trans-membrane region. This limitation gives to sequence based modelling efforts a crucial role in the sketching of a molecular interpretation of the fusion process. Moreover, our data also have a more general relevance for cell biology as the mechanism of intracellular fusion showed remarkable similarities with viral fusion</p

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Virulence Factors and Antifungal Susceptibility Profile of C. tropicalis Isolated from Various Clinical Specimens in Alexandria, Egypt

Background: The incidence of candidiasis caused by non-albicans Candida (NAC) species is increasing. Candida tropicalis has emerged as one of the most important NAC species. This study aims to examine the antifungal susceptibility profile and some virulence factors of C. tropicalis isolated from various clinical specimens. Methods: A total of 71 C. tropicalis isolates from various clinical specimens (69.01%, 18.31%, 9.86%, and 2.82% of isolates were collected from urine, respiratory samples, blood, and skin and soft tissue infections, respectively) from ICU patients in Alexandria, Egypt. The isolates were identified at species level by CHROMagar Candida and VITEK 2 compact system. Furthermore, the antifungal susceptibility was determined using the VITEK 2 system AST-YS07 card containing different antifungals. Hemolysin, phospholipase, and proteinase activity and biofilm formation were also tested as virulence factors. Results: Only 30 isolates (42.25%) were non-susceptible (MIC ≥ 4 µg/mL) to fluconazole, of which 28 isolates showed non-susceptibility (MIC ≥ 0.25 µg/mL) to voriconazole. All isolates showed both hemolysin and proteinase activities, while only 9 isolates (12.68%) showed phospholipase production and 70 isolates (98.59%) demonstrated biofilm formation. Strong biofilm production was observed among the blood culture isolates (85.71%), followed by the respiratory and urinary isolates (61.54% and 46.94%, respectively). Conclusions: This study sought to provide useful data on the antifungal susceptibility of C. tropicalis isolates from ICU patients suffering from invasive infections with an increased trend towards elevated MICs levels of both fluconazole and voriconazole. Due to the high incidence of systemic candidiasis and antifungal resistance, C. tropicalis is emerging as a serious root of infections. Therefore, early and accurate identification of Candida species along with susceptibility testing is of utmost importance

Relation between some environmental pollutants and recurrent spontaneous abortion

Reproductive health is exquisitely sensitive to characteristics of an individual’s environment including physical, biological, behavioral, cultural and socioeconomic factors. This study was launched to elucidate the effect of the exposure to chemical pollutants as aromatic amines viz. (benzidine, mono-acetyl benzidine, diacetyl benzidine, α,β-naphthylamine) as well as the biological pollutants e.g., human cytomegalovirus (HCMV) as risk factors for recurrent spontaneous abortion (RSA) through determination of MDA as a marker of oxidative stress and determination of some antioxidant markers. The results of the current study revealed that the aborter mothers were being exposed to environmental pollutants as aromatic amines which were manifested by the presence of benzidine, mono-acetyl-benzidine, di-acetyl-benzidine, α,β-naphthylamine in most of their urine samples, where the level of aromatic amines were more 13.6, 10, 15, and 4-folds than the control group, respectively. Also, the data suggest that in early pregnancy failure there is an increase in markers of oxidative stress and a probable decrease in maternal antioxidant defenses (22 nmol/ml and 17 mg/l, 550 U/l, respectively). Generation of ROS in large quantities, in the first trimester placenta which has limited antioxidant defenses may cause DNA damage, oxidation of protein and lipid resulting in extensive cell death. Also, it was demonstrated that high elevation of HCMV inhibits cytotrophoblasts proliferation, migration invasion and matrix metalloproteins (MMP) expression. Obviously, placental toxicological responses are partly due to pharmaco/toxico dynamic responses to the chemicals. Conclusively, the aforementioned findings emphasis that, the exposures to environmental chemical and/or biological risk factors are implicated in the pathogenesis of recurrent spontaneous abortion

High seroprevalence of antibodies to human herpesvirus-8 in Egyptian children: evidence of nonsexual transmission

man herpesvirus-8 (HHV-8) appears to be transmitted mainly by sexual con-tact. To evaluate the role of other trans-mission routes, especially in developing countries, we estimated the seropreva-lence of HHV-8 in Egyptian children, who, if seropositive, would have ac-quired the virus through a nonsexual route. Methods: Sera from 196 children (&lt;1–12 years of age), 20 adolescents (13–20 years of age), and 30 young adults (21–25 years of age) attending a vaccination program in Alexandria, Egypt, were studied. Immunofluores-cence assays were used to detect anti