Virulence and antimicrobial susceptibility of clinical and environmental strains of Aeromonas spp. from northeastern Brazil

Abstract

The aims of the present study were to isolate and identify clinical and environmental strains of Aeromonas spp. by means of biochemical tests and the automated method VITEK 2 and to investigate the presence of the virulence genes cytotoxic enterotoxin (act), hemolysin (asa-1), and type III secretion system (ascV), and also the in vitro antimicrobial susceptibility of the strains. From the clinical isolates, 19 Aeromonas hydrophila, 3 Aeromonas veronii bv. sobria, and 1 Aeromonas caviae were identified, while from the environmental strains, 11 A. hydrophila, 22 A. veronii bv. sobria, 1 A. veronii bv. veronii, and 1 A. caviae were recovered. The gene act was detected in 69.5% of clinical isolates, asa-1 in 8.6%, and ascV in 34.7%. In the environmental strains, the detection rates were 51.4%, 45.7%, and 54.2% for the genes act, asa-1, and ascV, respectively. Resistance to amoxicillin-clavulanate and piperacillin-tazobactam was observed in 15 and 3 clinical strains, respectively, and resistance to ceftazidime, meropenem, imipenem, ciprofloxacin, and trimethoprim-sulfamethoxazole was observed in 1 strain for each drug. Resistance to amoxicillin-clavulanate and piperacillin-tazobactam was detected in 17 and 1 environmental strain, respectively. Higher resistance percentages were observed in clinical strains, but environmental strains also showed this phenomenon and presented a higher detection rate of virulence genes. Thus, it is important to monitor the antimicrobial susceptibility and pathogenic potential of the environmental isolates.

Taxonomy, virulence determinants and antimicrobial susceptibility of Aeromonas spp. isolated from bacteremia in southeastern China

“…However, it may be explained by different expression level of the genes or interaction with other virulence factor not included in this study. Inconsistent with previous study [7], no particular pattern of virulence genes was observed in this study.…”

“…The prevalence and dangerousness of Aeromonas infections seems to be underestimated, as they vary among different geographic regions and type of infections [7], but there are not enough fundamental reports in many countries. Wenzhou, a coastal city located in southeast China with subtropical climate, is prone to Aeromonas infection due to the humid weather.…”

Virulence-Associated Genes and Antimicrobial Resistance of Aeromonas hydrophila Isolates from Animal, Food, and Human Sources in Brazil

“…Castelo-Branco et al [28] observed that Aeromonads of clinical origin had fewer virulence genes than those isolated from other sources. In our study, it was possible to observe variations in the relationship between virulence genes and source, thus indicating that the distribution of virulence genes among Aeromonas is not uniform.…”

Characterization of a new strain of Aeromonas dhakensis isolated from diseased pacu fish (Piaractus mesopotamicus) in Brazil

“…dhakensis and A. aquariorum) resistant to cefoxitin were also described by Esteve et al (2012) and Figueras et al (2009), agreeing with the findings of the present study to the South American strain. The resistance to meropenem, on the other hand, is noteworthy, as aeromonads are usually sensitive to carbapenems (Yucel & Erdogan 2010;Liu et al 2013;Adler et al 2014;Huang et al 2015;Perez et al 2015), and only a few strains have been reported as being resistant to this class of antibiotics (Figueira et al 2011;Castelo-Branco Dde et al 2015). The strain of A. dhakensis in the present study was not, however, fully resistant to carbapenems, as susceptibility to imipenem was observed.…”

“…; Castelo‐Branco Dde et al . ). The strain of A. dhakensis in the present study was not, however, fully resistant to carbapenems, as susceptibility to imipenem was observed.…”