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.