SARS-CoV-2 infection virological diagnosis.

SARS-CoV-2 infection has to be confirmed by virological diagnosis. Multiple diagnostic tests are available without enough perspective on their reliability. Therefore, it is important to choose the most suitable test according to its sensitivity and specificity but also to the stage of the disease. Currently, the RT-PCR detection of the viral genome in respiratory samples is the most reliable test to confirm the diagnosis of an acute SARS-CoV-2 infection. It has to be done in Class II biological safety laboratory. However, it may lack sensitivity, particularly in the advanced phase of infection, and depends closely on the samples' quality. Rapid PCR by cartridge system reduces response times but is not suitable for laboratories with high throughput of requests. Detection of virus antigens on respiratory samples is a quick and easy to use technique; however it has not good specificity and sensitivity and cannot be used for diagnosis and patient management. The detection of specific antibodies against SARS-CoV-2 is better used for epidemiological analyses. Research should be encouraged to overcome the limits of the currently available diagnostic tests.

Molecular profile of carbapenemase-producing Enterobacterales in burn patients.

BACKGROUND: Carbapenemase-producing Enterobacterales (CPE) present a threat to public health worldwide. AIM: To study their prevalence at the Trauma and Burn Center's Burn Unit and investigate their molecular characteristics and their associated antibiotics resistance patterns. METHODS: This is a retrospective study conducted at the Trauma and Burn Center's laboratory between july 2017 and december 2018. It included all patients hospitalized in the Trauma and Burn Center's Burn Unit infected with Enterobacterales resistant to carbapenems. The search of the carbapenemases genes was performed by PCR amplification GeneXpert® IV (Cepheid, Sunnyvale, CA, USA) by Xpert® Carba-R kit. RESULTS: During the study period, among 574 Enterobacterales, 64 strains (11.1%) were resistant to carbapenems, 58 strains (90.6%) of which were CPE. K. pneumoniae was the most predominant bacteria (n=50) fllowed by E. cloacae (n=7), P. mirabilis (n=3), E. aerogenes (n=2), E. coli (n=1) and P. rettgeri (n=1). The most common carbapenemase gene was blaNDM gene (58.6%) followed by blaOXA48 (24.1%). The co-existence of these two genes was identified in ten strains (17.3%). For the 58 CPE, resistance to ertapenem, imipenem and meropenem was 100%, 18.4% and 36.2%, respectively. The highest resistance rates were found to third-generation-cephalosporins (100%), ciprofloxacin (95%) and gentamicin (89.7%). Fosfomycin and colistin had the best susceptibility in vitro with only 5.2% and 4.8% of resistance, respectively. CONCLUSION: The high prevalence of CPE in our center requires continued screening and reinforcement of hygiene measures.

Science is a gateway for democracy.

The Arab Spring of 2011 has highlighted an unprecedent fact in the region: it was the young and educated population who established the spearheading of change, and led their countries to democracy. In this paper, we try to analyze how science has been a key factor in these moves, in Tunisia as well as in Egypt, and how it can help to anchor democracy in these countries.

Constitutive over-expression of pectinases in Penicillium occitanis CT1 mutant is transcriptionally regulated.

The CT1 mutant of Penicillium occitanis hyperproduces extracellular pectinases constitutively since it secretes pectinases even on glucose-containing medium. We show here that all other hydrolytic enzymes remain at low activities in CT1, confirming the specificity of the regulatory mutation towards pectinases. We isolated, by RT-PCR and through the construction of a cDNA library, three fragments coding for: a pectin lyase (pnl1), a polygalacturonase (pga1) and a pectate lyase (pal1). These fragments were used as probes in Northern blots analysis of the wild type strain CL100 and the CT1 mutant of P. occitanis grown in three culture conditions. The CT1 mutant showed a very high amount of pnl1, pga1 and pal1 mRNA either in pectin, glucose or glycerol grown cells while in the wild type CL100 strain, all transcripts were undetectable even on pectin. These results suggest that the CT1 mutation affects a trans-regulatory transcriptional factor regulating pectinase expression.

Identification and sequencing of ESTs from the halophyte grass Aeluropus littoralis.

Aeluropus littoralis (Gouan) Parl. is a C4 perennial halophyte monocotyledonous plant belonging to the same family as wheat. Growing as weed in dry salty areas or marshes, it is salt-secreting, rhizomatous and is used as forage. It is diploid (2n=2X=14) and has a relative small genome of around 342 Mb. A. littoralis is highly salt-tolerant since this plant has the ability to secrete salt. Thus, A. littoralis has the potential to become an important genetic resource for biotechnological strategies to improve salt and drought tolerance in economically important crops such as wheat. We have constructed SSH (Suppression Subtractive Hybridization) cDNA libraries from root (RSD45) and leaf (LSD45) tissues of 45 days old plants grown in the presence of 300 mM NaCl. We have also constructed full-length cDNA library from 15 days old salt stressed (300 mM NaCl) roots (RSTL15). Sequencing revealed 25 and 42 independent transcripts from the RSD45 and LSD45 cDNA libraries respectively, in both cases this was less than 25% of the clones sequenced. In contrast, 425 (60%) of the clones from the RSTL15 library revealed independent transcripts. After comparison with protein databases using BlastX, 335 (68%) ESTs (Expressed Sequence Tag) were classified into putative known functions and unclassified proteins, 59 (12%) have homology only to unidentified homologous sequences. A total of 98 (20%) of the ESTs have no homologies to known sequences in the protein databases which can be considered as novel.