Search

Objectives Escherichia coli producing metallo-β-lactamases with penicillin-binding protein 3 (PBP3) insertions have reduced susceptibility to aztreonam–avibactam and cefiderocol. Here, we analysed high-quality E. coli genomes for PBP3 insertions. Methods E. coli genomes (n  = 167 518) were retrieved from EnteroBase with CheckM2 for quality control, fastANI for species confirmation, multi-locus sequencing typing for sequence type (ST) determination and AMRFinderPlus for resistance gene identification. For PBP3 insertion analysis, we used Prokka for predicting coding sequences, BLAST+ for comparing resulted protein sequences and SnpEff for annotating variants. Results Among the included 159 341 genomes, PBP3 insertions with 11 variants were found in 2.01% (n  = 3198). The predominant variant is a duplication of 334–337 amino acids (aa) (94.75%, n  = 3030), comprising YRIN (65.92%, n  = 2108) and its single-aa-variant YRIK (28.83%, n  = 922), followed by a similar PYRI duplication of 333–336 (4.16%, n  = 133). The less common ones are a TIPY duplication of 331–334 (n  = 24) and its single-aa-variant TVPY's duplication: TVVPY (n  = 1), TVPYTVPY (n  = 1) and TVPYPVPY (n  = 1). Rare duplications include VGDR of 106–109 (n  = 3), ANALNIPL of 114–121 (n  = 3), AL of 567–568 (n  = 1) and TG of 584–585 (n  = 1). Insertion variants were detected across 62 countries on six continents, primarily in human samples, and associated with 85 STs, concentrated in high-risk clones ST410 (29.18%, n  = 1923), ST167 (23.40%, n  = 1740) and ST405 (10.56%, n  = 1334), with 83.32% (n  = 2218) encoding metallo-β-lactamase NDM. Conclusions Global spread of E. coli harbouring PBP3 insertion, often with NDM β-lactamase, high-risk ST410, ST167 and ST405 clones and various hosts, underscores the escalating antimicrobial resistance crisis and the urgency for a 'One Health' strategy. [ABSTRACT FROM AUTHOR]

Background: Respiratory syncytial virus (RSV) causes the most common type of severe lower respiratory tract infection worldwide, and the fusion (F) protein is a target for neutralizing antibodies and vaccine development. This study aimed to investigate the immunogenicity and efficacy of an mRNA-based RSV vaccine with an F protein sequence. Methods: We designed an mRNA construct encoding a modified RSV F protein, which was further developed into an LNP-encapsulated mRNA vaccine (LVRNA007). LVRNA007 was administered to mice and cotton rats, followed by immunogenicity analysis and viral challenge studies. Protection of rodents from the viral infection was evaluated based on the presence of the virus in the lung and pathological examination of respiratory tissues. Results: LVRNA007 induced robust humoral and cellular immune responses in both mice and cotton rats, with neutralization antibody levels in the immunized animals maintained at high levels for over one year. Vaccination of LVRNA007 also protected the rodents from RSV challenge, judged by the much decreased virus titer and the pathological score in the lung tissue. In addition, no vaccine-enhanced disease (VED) phenomenon was observed with LVRNA007 vaccination. Conclusions: Based on the preclinical immunogenicity and efficacy data, LVRNA007 could be a potential promising vaccine for prophylaxis of RSV infection. [ABSTRACT FROM AUTHOR]

Aiming at the problem of tracking failure caused by rotation, occlusion and deformation of moving target in video sequence, a tracking method based on multi-region segmentation of target was proposed. The target is divided into multiple overlapping regions, and then multiple regions that are relatively stable in the tracking process are selected for positioning, and then different target region weights are used to update different template updating strategies for the tracked target. In this way, the anti-blocking and anti-rotation ability of the algorithm can be increased. Experimental results show that the proposed method is adaptive to occlusion and rotation.