Virulence determinants in genetically heterogeneous populations of Aeromonads recovered from an urban lagoon

Abstract

The diversity and distribution of Aeromonas spp. associated with virulence profiles from the Rodrigo de Freitas Lagoon were investigated using phylogenetic analysis of gyrB/rpoB gene sequences for speciation. The concatenated gyrB/rpoB gene sequences clustered into five species: Aeromonas punctata/caviae (n ¼ 37), A. hydrophila (n ¼ 10), A. dhakensis (n ¼ 16), A. jandaei (n ¼ 1) andA. enteropelogenes/trota (n ¼ 3). The virulence genes (atc/aerA/hlyA/asp/amp) resulted in 19 virulence profiles, distributed heterogeneously among the five Aeromonas species. Out of the 67 isolates, 16% presented five distinct profiles carrying four virulence genes and 7% showed all genes investigated. The hemolytic genes were detected as follows: act 54% (37/67), aerA 36% (24/67), hlyA 26% (18/67) and proteolytic genes such as asp 36% (24/57) and amp in 85% (57/67) were widely distributed in lagoon sampling stations. Meanwhile, 88% (59/67) and 92% (62/67) of the isolates showed hemolytic and proteolytic activity, respectively. Our results demonstrated that concatenated sequences of the gyrB and rpoB genes showed to be an adequate approach for the Aeromonas speciation and prevalence. The high heterogeneity of virulence genes among the species resulted in several virulence profiles, as well as high percentages of hemolytic and proteolytic activity, demonstrating the necessity of further epidemiological surveys of Aeromonas species pathogenicity in an aquatic recreational lagoon.

Hiding in Plain Sight: Characterization of Aeromonas Species Isolated from a Recreational Estuary Reveals the Carriage and Putative Dissemination of Resistance Genes

“…Indeed, several studies have already reported the transport of ARGs, antimicrobial residues, heavy metals, and other pollutants in this kind of effluent [10,19]. Hence, the isolation of antimicrobial and heavy metal-resistant Aeromonas strains in a recreational environment raises attention to the potential risks associated with human exposure to these waters or the consumption of seafood from this region [20,21]. Although cases of Aeromonas spp.…”

Aeromonas dhakensis: A Zoonotic Bacterium of Increasing Importance in Aquaculture

“…In addition to infecting fish and humans, A. dhakensis isolates have been cultivated from marine mammals [ 18 , 19 ], rodents [ 20 , 21 ], reptiles [ 22 , 23 ] and invertebrates [ 24 , 25 , 26 ]. Moreover, microbiological screens have detected A. dhakensis in otherwise healthy populations of fish [ 7 ] and people [ 27 ], various aquatic environments including river water [ 28 , 29 ], lagoons [ 30 ], drinking water [ 31 ] and wells [ 32 ], as well as sewage [ 33 ] and foodstuffs [ 34 , 35 , 36 ].…”