Characterization of pathogenic Aeromonas veronii bv. veronii associated with ulcerative syndrome from Chinese longsnout catfish (Leiocassis longirostris Günther)

Abstract

ABSTRACT273 bacterial strains were isolated from 20 Chinese longsnout catfish samples. The biochemical characteristics of all strains conformed to the species description of Aeromonas veronii bv. veronii on the basis of Vitek GNI+ card. Furthermore, 16S rDNA, gyrB and rpoD sequences of the representative strain PY50 were sequenced and showed high similarity with A. veronii bv. veronii in Genbank. Antibioticresistance of the representative strain PY50 was assessed by the Kirby-Bauer disk diffusion method, and the results showed it was susceptible and moderately susceptible to 13 and 4 of the 21 antimicrobial agents tested. Extracellular products of strain PY50 contained gelatinase, lecithinase, elastase, most of lipase and lipopolysaccharide. Virulence of strain PY50 and extracellular products to Chinese longsnout catfish were also tested, and LD 50 were about 3.47×10 4 CFU per fish and 11.22 g per fish in intraperitoneal injection respectively. This is the first report that A. veronii bv. veronii was the pathogenic agent of ulcerative syndrome in Chinese longsnout catfish.

Characterization of Aeromonas sobria Isolated from Fish Rohu (Labeo rohita) Collected from Polluted Pond

“…Edwardsiella tarda indicated 98% probability in Vitek System 2 test which is in consonance with the present study [37]. Similarly, the results from the Vitek database indicated that the percent probabilities of identification of A. veronii were 95 to 99%, however the percent probabilities of identification of A. hydrophila, A. caviae and A. sorbia were only 69 to 83% [38] and A. sobria was 93% [17].…”

Structural Studies of the Lipopolysaccharide from the Fish Pathogen Aeromonas veronii Strain Bs19, Serotype O16

“…Amongst mesophilic and motile species, A. hydrophila , A. caviae , A. sobria , and A. veronii have been described as important fish pathogens. They cause chronic disease with open dermal ulcers and other pathological lesions or acute systemic infection referred to as motile aeromonad septicemia (MAS) [5,6,7]. …”

“…sobria septicemia incidences in immunocompromised patients [22,23]. Nevertheless, this species is commonly known as fish pathogen, especially associated with ulcerative syndrome [6,7]. In the light of the increased Aeromonas infection incidence rate and the economic importance of these diseases in fish farms as well as possible public health effects, it is essential to characterize the virulence factors of these bacteria.…”

Antibacterial potential of phytochemicals alone or in combination with antimicrobials against fish pathogenic bacteria

“…Aeromonas veronii is a highly pathogenic species to fish, presenting several virulence factors (Sun et al 2016). It has been described as species has antibiotic resistance genes and also as responsible for ulcerative syndrome in Chinese longsnout catfish (Leiocassis longirostris) (Cai et al 2012;Sreedharan et al 2012). Bacteria of the genus Aeromonas are recognized for their capacity of haemolysis and biofilm formation, factors that interfere in the strain virulence (Millezi et al 2013;Sutili et al 2014).…”