The ability to detect an infectious agent in a widespread epidemic is crucial to the success of quarantine efforts in addition to sensitive and accurate screening of potential cases of infection from patients in a clinical setting. Enabling testing outside of sophisticated laboratories broadens the scope of control and surveillance efforts, but also requires robust and simple methods that can be used without expensive instrumentation. Here we report a method to identify SARS-CoV-2 (COVID-19) virus RNA from purified RNA or cell lysis using loop-mediated isothermal amplification (LAMP) using a visual, colorimetric detection. This test was additionally verified using RNA samples purified from respiratory swabs collected from COVID-19 patients in Wuhan, China with equivalent performance to a commercial RT-qPCR test while requiring only heating and visual inspection. This simple and sensitive method provides an opportunity to facilitate virus detection in the field without a requirement for complex diagnostic infrastructure.

To fully decipher the immunogenicity of the SARS-CoV-2 Spike protein, it is essential to assess which part is highly immunogenic in a systematic way. We generate a linear epitope landscape of the Spike protein by analysing the serum IgG response of 1,051 COVID-19 patients with a peptide microarray. We reveal two regions rich in linear epitopes, i.e., CTD and a region close to the S2’ cleavage site and fusion peptide. Unexpectedly, we find that the RBD lacks linear epitope. We reveal that the number of responsive peptides is highly variable among patients and correlates with disease severity. Some peptides are moderately associated with severity and clinical outcome. By immunizing mice, we obtained linear-epitope-specific antibodies; however, no significant neutralizing activity against the authentic virus was observed for these antibodies. This landscape will facilitate our understanding of SARS-CoV-2-specific humoral responses and might be useful for vaccine refinement.

Bacteriophage lysins, the highly evolved specific peptidoglycan hydrolases, have long been demonstrated to be effective enzybiotics in various infectious models. The modular structure of lysins makes it possible to design bioengineered lysins that have desired properties, such as higher activity, or broader killing spectrum. Moreover, lysins can even be engineered to kill Gram-negative bacterial pathogens from without, a property that is not present in natural lysins. In this era of ever increasing multidrug resistant pathogens, engineered lysins represent a new class of enzybiotics that are powerful and readily available to fight antimicrobial resistance.

The increasing emergence of multi-drug resistant streptococci poses a serious threat to public health worldwide. Bacteriophage lysins are promising alternatives to antibiotics; however, their narrow lytic spectrum restricted to closely related species is a central shortcoming to their translational development. Here, we describe an efficient method for rapid screening of engineered chimeric lysins and report a unique “chimeolysin”, ClyR, with robust activity and an extended-spectrum streptococcal host range against most streptococcal species, including S. pyogenes, S. agalactiae, S. dysgalactiae, S. equi, S. mutans, S. pneumoniae, S. suis and S. uberis, as well as representative enterococcal and staphylococcal species (including MRSA and VISA). ClyR is the first lysin that demonstrates activity against the dominant dental caries-causing pathogen as well as the first lysin that kills all four of the bovine mastitis-causing pathogens. This study demonstrates the success of the screening method resulting in a powerful lysin with potential for treating most streptococcal associated infections.

The rapid spread and emergence of multidrug-resistant Acinetobacter baumannii and other pathogenic Gram-negative bacteria spurred scientists and clinicians to look for alternative therapeutic agents to conventional antibiotics. In the present study, an A. baumannii bacteriophage p54 was isolated and characterized. Morphological and genome analysis revealed that bacteriophage p54 belongs to Myoviridae family with a genome size of 165,813 bps. A novel endolysin, namely LysAB54, showing low similarity with other well-known related endolysins, was cloned, expressed, and characterized from the bacteriophage p54. LysAB54 showed significant bactericidal activity against multidrug-resistant A. baumannii and other Gram-negative bacteria, including Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli, in the absence of outer membrane permeabilizers. Based on all those observations, LysAB54 could represent a potential agent for the treatment of multidrug-resistant Gram-negative superbugs.