Biology subjects

Vicente, A. C.

Publications and source records attributed to Vicente, A. C..

4 recordsLinked to original sources

bioRxiv2022

Global genomic epidemiology, resistome, virulome and plasmidome of the Extraintestinal Pathogenic Escherichia coli (ExPEC) ST38 lineage

Most of the extraintestinal human infections worldwide are determined by some specific Extraintestinal Pathogenic Escherichia coli (ExPEC) lineages, which also present a zoonotic character. One of these lineages belongs to ST38, which is considered a uropathogenic/enteroaggregative E. coli hybrid and a high-risk globally disseminated ExPEC. To get insights on the aspects of ST38 epidemiology and evolution as a multidrug resistant and pathogenic lineage, this study performed a global comparative genomic analysis on ST38 genomes. A total of 376 genomes recovered from environments, humans, livestock, wild and domestic animals in all continents throughout three decades were analyzed considering the ST38 phylogenomics, resistome, plasmidome, and virulome. In general, our analyses revealed that, independently of host sources and geographic origin, these genomes were distributed in two clusters comprising clonal and non-clonal genomes. Moreover, the ST38 accessory genome was not strictly associated with clusters and sub-clusters. Interestingly, the High Pathogenicity Island (HPI) prevailed in the major cluster (cluster 2), which comprised most of the genomes from human origin recovered worldwide (2000 to 2020). In addition, the ExPEC ST38 harbors a huge and diverse plasmidome that might contribute to the evolution of this lineage, reflecting in ST38 ability to live in a diversity of niches as a commensal or pathogenic organism.

genomics↗

bioRxiv2021

Conjugative transfer of naturally occurring plasmids in Mycolicibacterium sp.

Conjugation is considered the main horizontal gene transfer (HGT) mechanism in bacterial adaptation and evolution. In the Mycobacteriaceae family, Mycolicibacterium smegmatis has been used as the model organism for the conjugative transfer of hybrid plasmids. However, the natural conjugation process in any bacteria would involve the transfer of naturally occurring plasmids. Currently, there is a gap in this regard in relation to this abundant environmental genus of Mycobacteriaceae. Here, we performed conjugation experiments between wild Mycolicibacterium sp. strains involving naturally occurring plasmids (sizes of 21 and 274 kb), and interestingly, evidence of conjugative transfer was obtained. Thus, it is likely that conjugation occurs in Mycolicibacterium in the natural environment, representing a source of diversification and evolution in this genus of bacteria.

microbiology↗

bioRxiv2021

Emergence of XDR high-risk Pseudomonas aeruginosa ST309 in South America: a global comparative genomic analysis

Pseudomonas aeruginosa has been considered one of the major nosocomial pathogens associated with elevated morbidity and mortality worldwide. Outbreaks have been associated with few high-risk pandemic P. aeruginosa lineages, presenting a remarkable antimicrobial resistance. However, the biological features involved with the persistence and spread of such lineages among clinical settings remain to be unravel. This study reports the emergence of the ST309 P. aeruginosa lineage in South America/Brazil, more precisely, in the Amazon region. Global genomic analyses were performed with the Brazilian strain (PA834) and more 41 complete and draft ST309 genomes publicly available, giving insights about ST309 epidemiology and its resistome and mobilome. Antimicrobial susceptibility tests revealed that the Brazilian PA834 strain presented the XDR phenotype, which was mainly due to intrinsic resistance mechanisms. Genomic analyses revealed a heterogeneous distribution of acquired antimicrobial resistance genes among ST309 genomes, which included blaVIM-2, blaIMP-15 and qnrVC1, all of them associated with class 1 integrons. The mobilome mining showed the presence of Integrative and Conjugative Elements, transposons and genomic islands harbouring a huge arsenal of hevy metal resistance genes. Moreover, these elements also carried genes involved with virulence and adaptive traits. Therefore, the presence of such genes in ST309 lineage possibly accounted for the global spread and persistence of this emerging clone, and for its establishment as a pandemic lineage of clinical importance.

genomics↗

bioRxiv2019

Yellow Fever Vaccine Protects Resistant and Susceptible Mice Against Zika Virus Infection

Zika virus (ZIKV) emerged as an important infectious disease agent in Brazil in 2016. Infection usually leads to mild symptoms but severe congenital neurological disorders and Guillain-Barre syndrome have been reported following ZIKV exposure. The development of an effective vaccine against Zika virus is a public health priority, encouraging the preclinical and clinical studies of different vaccine strategies. Here, we describe the protective effect of an already licensed attenuated yellow fever vaccine (17DD) on type-I interferon receptor knockout mice (A129) and immunocompetent (BALB/c) mice infected with ZIKV. Yellow fever virus vaccination results in robust protection against ZIKV, with decreased mortality in the A129 mice, a reduction in the cerebral viral load in all mice, and weight loss prevention in the BALB/c mice. Despite the limitation of yellow fever (17DD) vaccine to elicit antibody production and neutralizing activity against ZIKV, we found that YF immunization prevented the development of neurological impairment induced by intracerebral virus inoculation in adult. Although we used two vaccine doses in our protocol, a single dose was protective, reducing the cerebral viral load. Different Zika virus vaccine models have been tested; however, our work shows that an efficient and certified vaccine, available for use for several decades, effectively protects mice against Zika virus infection. These findings open the possibility for using an available and inexpensive vaccine to a large-scale immunization in the event of a Zika virus outbreak.

immunology↗