2022

Infections by antibiotic-resistant bacteria are a significant and complex global health issue. In this context, Acinetobacter baumannii is particularly important because of its ability to withstand treatments by β-lactams, such as carbapenem. The objective of this work was to investigate, through systematic analysis and meta-analysis, the chance of resistance to carbapenem in A. baumannii strains. For this, a search was conducted for the PubMed and Cochrane databases based on the keywords: “Acinetobacter baumannii” AND “beta-lactam” OR “penicillin” OR “cephalosporin” OR “cephamycin” OR “carbapenem” OR “monobactam”. The initial search resulted in a total of 90,475 articles. It was filtered based on eligibility criteria, and eight articles were selected for analysis. An odds ratio value equivalent to 3.55 was obtained, indicating a high chance of resistance to the carbapenem of strains of the species. Therefore, it is supposed that A. baumannii infection cases have a high probability of not responding adequately to treatments based on carbapenem.

Xanthomonas bacteria are known phytopathogens difficult to control in the field, which cause great losses in many economically important crops. Genomic islands are fragments acquired by horizontal transference that are important for evolution and adaptation to diverse ecological niches. Virulence and pathogenicity islands (PAIs) enhance molecular mechanisms related to host adaptation. In this work, we have analyzed 81 genomes belonging to X. campestris, and a complex group of X. citri, X. axonopodis, and X. fuscans belonging to nine different pathovars and three subspecies, to analyze and compare their genomic contents. Xanthomonas pan-genome is open and has a massive accessory genome. Each genome showed between three and 15 exclusive PAIs, well conserved through strains of the same pathovar or subspecies. X. axonopodis pv. anacardii had higher general similarity to X. citri subsp. citri and X. fuscans subsp. aurantifolii, with which a few PAIs were shared. Genomic synteny was even for almost all strains, with few rearrangements found in X. axonopodis pv. anacardii. The prophage regions identified in the genomes were mostly questionable or incomplete, and PAI13 in X. campestris pv. campestris ATCC33913 matched a prophage region of 19 transposable elements. Finally, PAIs in Xanthomonas are pathovar-specific, requiring individual strategies of combat.

Probiotics are health-beneficial microorganisms with mainly immunomodulatory and anti-inflammatory properties. Lactobacillus delbrueckii species is a common bacteria used in the dairy industry, and their benefits to hosting health have been reported. This study analyzed the core genome of nine strains of L. delbrueckii species with documented probiotic properties, focusing on genes related to their host health benefits. For this, a combined methodology including several software and databases (BPGA, SPAAN, BAGEL4, BioCyc, KEEG, and InterSPPI) was used to predict the most important characteristics related to L. delbrueckii strains probiose. Comparative genomics analyses revealed that L. delbrueckii probiotic strains shared essential genes related to acid and bile stress response and antimicrobial activity. Other standard features shared by these strains are surface layer proteins and extracellular proteins-encoding genes, with high adhesion profiles that interacted with human proteins of the inflammatory signaling pathways (TLR2/4-MAPK, TLR2/4-NF-κB, and NOD-like receptors). Among these, the PrtB serine protease appears to be a strong candidate responsible for the anti-inflammatory properties reported for these strains. Furthermore, genes with high proteolytic and metabolic activity able to produce beneficial metabolites, such as acetate, bioactive peptides, and B-complex vitamins were also identified. These findings suggest that these proteins can be essential in biological mechanisms related to probiotics’ beneficial effects of these strains in the host.