The CRISPR-Cas system in clinical strains of Acinetobacter baumannii: an in-silico analysis

Acinetobacter baumannii is a relevant bacterium due to its high-resistance profile. It is well known that antimicrobial resistance is primarily linked to mutations and the acquisition of external genomic material, such as plasmids or phages, to which the Clustered Regularly Interspaced Short Palindromic Repeats associated with Cas proteins, or CRISPR-Cas, system is related. It is known that the system can influence the acquisition of foreign genetic material and play a role in various physiological pathways. In this study, we conducted an in-silico analysis using 91 fully assembled genomes of clinical strains obtained from the NCBI database. Among the analyzed genomes, the I-F1 subtype of the CRISPR-Cas system was detected showcasing variations in architecture and phylogeny. Using bioinformatic tools, we determined the presence, distribution, and specific characteristics of the CRISPR-Cas system. We found a possible association of the system with resistance genes but not with virulence determinants. Analysis of the system's components, including spacer sequences, suggests its potential role in protecting against phage infections, highlighting its protective function.

Markers of pathogenicity islands in strains of Aeromonas species of clinical and environmental origin

The aim of this study was to investigate the presence of markers of pathogenicity islands that may be informative to detect the virulent PAI carriers of clinical and environmental strains of Aeromonas spp. isolated in Mexico. virB2, virB9 and virB11 genes were found in Aeromonas strains isolated from environmental and clinical sources while cagE and tfc16 genes were only in strains of environmental origin. Having performed the wide screening presented in this study, we now have a set of strains to map and confirm the presence of a pathogenicity island in Aeromonas strains isolated in Mexico.