Development and design of CRISPR-based diagnostic for Acinetobacter baumannii by employing off-target gene editing of sgRNA

Abstract

Acinetobacter baumannii is widely recognized as a human opportunistic pathogen in nosocomial infections. The proliferation of multidrug-resistant strains of A. baumannii has presented an array of difficulties for clinical anti-infective therapies and diagnostic procedures, owing to the existence of numerous variations. The development of therapy utilizing CRISPR/Cas9 for treatment and diagnosis necessitates an in-depth study of potential off-target consequences. The objective of this work is to assess potential off-target effects associated with a single guide RNA (sgRNA) designed to identify several variants present in A. baumannii. The current investigation involved the identification of Cas12 nuclease-specific protospacer adjacent motif (PAM) and downstream target sequences. This was achieved by utilizing computational tools and software to analyze conserved sections of the A. baumannii siderophore protein gene. Further, the in-silico expression vector was created with the SnapGene software. A total of 24 potential off-target sequences were identified in these sequences with 100% query identity with 96 different A. baumannii strains. In addition, a target-specific oligonucleotide single-guide RNA (sgRNA) template was synthesized by appending an additional nucleotide 'G' to the 5′ end. This research uses A. baumannii as an example of a problem that affects all treatments and diagnosis procedures to illustrate the significance of screening off-targets in different variants of a pathogen. Our findings may impact the safety and effectiveness of CRISPR/Cas9, which may have wider implications for additional targets that are currently being used therapeutically.