Aeromonas spp.: An Emerging Nosocomial Pathogen

Abstract

Aeromonads are hallophillic, nonacid fast, nonspore forming, Gram-negative rods which are widely distributed in the soil, foodstuffs, and aquatic environment. Since times immemorial, they are important zoonotic pathogens of poikilotherms but are now emerging as important human pathogens. These emerging enteric pathogens flourish in the water distribution system by forming biofilms. They possess large number of virulence factors including inherent resistance to various antibiotics and ability to form biofilms using quorum sensing. These properties make them easy pathogens for human infections. Aeromonads are important enteric pathogens, but, with the growing level of immunosuppression in the population, they have been associated with various extraintestinal infections, such as skin and soft-tissue infections, traumatic wound infections, and lower respiratory tract/urinary tract infections. The average annual incidence of bacteremia in Southern Taiwan due to Aeromonas spp. was 76 cases/million inhabitants between 2008 and 2010. However, the incidence reported from Western countries is much lower. The case fatality rate among patients with Aeromonas bacteremia ranges from 27.5 to 46%. Aeromonads are universally resistant to the narrow-spectrum penicillin group of antibiotics such as penicillin, ampicillin, carbenicillin, and ticarcillin. They are however susceptible to piperacillin, azlocillin, second and third generation cephalosporins, and carbapenems. Most of the Aeromonas species are susceptible to aminoglycosides, tetracycline, chloramphenicol, trimethoprim-sulfamethoxazole, quinolones, and monobactams. This manuscript is a comprehensive systematic review of the literature available on Aeromonas spp.

Aeromonas

“…However, in a study performed in Valencia (Spain) the average annual incidence was reported to be 20 cases per million inhabitants (Esteve et al, 2015). Overall estimates of regional prevalence are summarized in Table 1. In Asia Aeromonas seems to be more frequent, for instance in a 3-year study (2008 to 2010) performed by Wu et al (2014) in South Taiwan they found 76 cases of Aeromonas bacteremia per million population, while in studies performed in the UK and the United States indicated an incidence of 1.5 cases per million population (Janda and Abbot, 2010;Batra et al, 2016). We have to consider that normally hospitals do not use a specific culture media for the recovery of Aeromonas, being generally discovered by chance from media dedicated to recover other bacterial pathogens.…”

“…Aeromonas cases have been described from all over the world, although the incidence of gastroenteritis appears higher in undeveloped or developing regions. In relation to bacteremia or septicemia the incidence is higher in Asian countries, probably due to a higher incidence of cirrhosis, which is an important underlying condition link to Aeromonas bacteremia (Figueras and Beaz-Hidalgo, 2015;Batra et al, 2016).…”

First hybrid complete genome ofAeromonas veroniireveals chromosome-mediated novel structural variantmcr-3.19from human clinical specimen

“…Aeromonas spp are ubiquitous and were known to cause gastroenteritis, wound infections, and septicemia, commonly known as "Jack of all trades". Aeromonads had been universally resistant to the penicillin group of antibiotics (penicillin, ampicillin, carbenicillin, and ticarcillin) and are generally susceptible to tetracyclines and quinolones [1]. Recently, increasing resistance to third-generation cephalosporins and carbapenems are reported [2,3].…”

Genes de virulencia en Aeromonas spp. (Aeromonadales: Aeromonadaceae) aisladas de Oreochromis spp. (Perciformes: Cichlidae) para consumo humano en México

“…Esta bacteria es considerada un patógeno entérico emergente que además se asocia a infecciones de heridas, en sistema hepatobiliar, tracto respiratorio, tejidos blandos y septicemia en humanos (Janda & Abbott, 2010;Figueras & Beaz-Hidalgo, 2015;Batra Mathur, & Misra, 2016).…”

“…El género Aeromonas posee una variedad de factores de virulencia como componentes estructurales y toxinas, además el género Aeromonas tiene la capacidad de capturar e integrar factores de virulencia en su genoma (Palma-Martínez et al, 2016) mismos que están involucrados en la colonización, invasión y proliferación de la bacteria conduciendo al desarrollo de la infección (Figueras & Beaz-Hidalgo, 2015;Batra et al, 2016). Las manifestaciones clínicas en infecciones por Aeromonas sugieren que múltiples factores de virulencia actúan en conjunto, por lo que la virulencia podría ser específica de cada cepa que interviene evadiendo el sistema inmunitario mediante sus propias estrategias (Yu et al, 2005;Tomás, 2012).…”