Potential pathogenicity ofAeromonas hydrophilacomplex strains isolated from clinical, food, and environmental sources

Abstract

Aeromonas are autochthonous inhabitants of aquatic environments, including chlorinated and polluted waters, although they can also be isolated from a wide variety of environmental and clinical sources. They cause infections in vertebrates and invertebrates and are considered to be an emerging pathogen in humans, producing intestinal and extra-intestinal diseases. Most of the clinical isolates correspond to A. hydrophila, A. caviae, and A. veronii bv. Sobria, which are described as the causative agents of wound infections, septicaemia, and meningitis in immunocompromised people, and diarrhoea and dysenteric infections in the elderly and children. The pathogenic factors associated with Aeromonas are multifactorial and involve structural components, siderophores, quorum-sensing mechanisms, secretion systems, extracellular enzymes, and exotoxins. In this study, we analysed a representative number of clinical and environmental strains belonging to the A. hydrophila species complex to evaluate their potential pathogenicity. We thereby detected their enzymatic activities and antibiotic susceptibility pattern and the presence of virulence genes (aer, alt, ast, and ascV). The notably high prevalence of these virulence factors, even in environmental strains, indicated a potential pathogenic capacity. Additionally, we determined the adhesion capacity and cytopathic effects of this group of strains in Caco-2 cells. Most of the strains exhibited adherence and caused complete lysis.

Isolation, Identification and Characteristics of Aeromonas veronii From Diseased Crucian Carp (Carassius auratus gibelio)

“…A pair of primer gyrB-F: 5 -GAAGTCATCATGACCGTTCTGCA(TC)GC(TCAG)GG(TCA G)GG(TCAG)AA(AG)TT(TC)GA-3 and gyrB-R: 5 -AGCAGGGTACGGATGTGCGAGCC(AG)TC(TCAG)AC(AG) TC(TCAG)GC(AG)TC(TCAG)GTCAT-3 (Yamamoto and Harayama, 1995) was used for amplification of the gyrB gene. PCR amplification was performed using a Biometra TProfessional Thermocycler (TaKaRa, Japan) according to a previous report (Albarral et al, 2016). The amplified products were observed and then sequenced at Sangon (Shanghai, China).…”

Potentially pathogenic bacteria isolated from diverse habitats in Spitsbergen, Svalbard

“…The expression of hemolysins has infrequently been assessed in bacterial isolates from environmental samples (Bevivino et al 2002;González-Rodríguez et al 2007;Albarral et al 2016) and much less is known about the hemolytic activity of Arctic species. As warming global temperatures are favoring the geographic expansion of pathogens and increasing the risk of human exposure to infectious disease (Revich et al 2012;IPCC 2014), it is increasingly important to study the presence of potential pathogens in Arctic environments and the expression of virulent phenotypes.…”

N-Acylhomoserine Lactones (AHLs), QseB/C Gene Detection, Virulence Factors and Antibiotics Resistance of <i>Aeromonas hydrophila</i>

“…Bacterial biofilm formation is a complicated multifaceted mechanism, associated with attachment, quorum sensing, cell wall synthesis, metabolism, and stress response [32]. The increasing antimicrobial resistance and virulence of bacterial species are due to their ability to produce biofilms [7]. All the isolates from our study are strong biofilm producers.…”

“…The pathogenic virulence factors of A. hydrophila include adhesions, cytotoxins, hemolysins, and proteases, and are able to form biofilms and alter gene expression and metabolic pathways under various host environments [5] [6]. Over the years, research on A. hydrophila has shown that they stick to hard exteriors and establish biofilms on the glass exteriors, polystyrene, polyvinyl chloride, and stainless steel [7]. Biofilms are considered as the leading root of perpetual infection and drug resistance, largely because of their ability to align with the visceral organs and other material surfaces [8].…”