Aeromonas spp.: fatores de virulência e perfis de resistência a antimicrobianos e metais pesados

Abstract

RESUMOAs bactérias do gênero Aeromonas spp. são considerados como patógenos oportunistas carreadores de múltiplos fatores de virulência. O fenômeno da resistência aos antimicrobianos e metais pesados constitui outro problema, podendo ocorrer por diferentes fatores, dentre eles o uso indiscriminado de agentes antimicrobianos, poluição ambiental e a presença de mecanismos de resistência, como bombas de efluxo, sendo que muitos destes podem ser transmitidos por elementos genéticos móveis como os plasmídeos. O objetivo desse artigo é fazer uma revisão bibliográfica sobre os fatores de virulência, resistência a antimicrobianos e metais pesados, bem como os mecanismos que podem intervir nessa resistência e sua transferência entre bactérias do gênero Aeromonas. Os estudos dos fatores envolvidos no mecanismo de surgimento da resistência, aliado aos estudos de biologia molecular, fornecem subsídios para elaboração de métodos de controle e profilaxia dessas enfermidades de impacto aos organismos aquáticos, seres humanos e meio ambiente. PALAVRAS-CHAVE: Micro-organismos, fatores de virulência, plasmídeo, bomba de efluxo.ABSTRACT AEROMONAS SPP.: VIRULENCE FACTORS AND RESISTANCE PATTERNS TO ANTIMICROBIAL AND HEAVY METALS. Bacteria from Aeromonas spp. genus are considered as opportunistic pathogens that can carry many virulence factors. The resistance phenomenon to antimicrobial drugs and heavy metals is another problem and may occurs by several factors, as the indiscriminate usage, environmental pollution and the presence of resistance determinants as efflux pumps, being many of them transmitted by genetic mobile elements as plasmid. The purpose of this article is to review about the virulence factors, antimicrobial and heavy metal resistance, as well as the mechanisms that can help its transfer among Aeromonas genus bacteria. Studies of the resistance mechanisms associated to molecular biology could produce information about control and prophylaxis methods to this disease of impact on aquatic organisms, man and environment.

<b>Aquatic microbiota diversity in the culture of Nile tilapia (<i>Oreochromis niloticus</i>) using bioflocs or periphyton: virulence factors and biofilm formation

“…In this treatment only two virulence profiles were observed. In the case of environmental unbalance or the use of inadequate procedures in the culture, diseases might appear, causing high mortality rates and economic losses, since these genera are known for possessing various opportunistic pathogenic species (Peixoto, Sá, Gordiano, & Costa, 2012). The strains isolated from Treatment 4 presented up to four of the six virulence factors, while also being positive for biofilm formation (Table 1).…”

“…Sung and Hong (1997) isolated Aeromonas and Pseudomonas from freshwater shrimp Macrobrachium rosembergii and identified that these bacteria were able to produce four and five extracellular products, respectively. The virulence of Aeromonas is considered multifactorial, as it is practically impossible to establish a hierarchy in the classification of its virulence factors according to their part in the disease process, and the following factors have been identified as virulence indicators: hemolysins, proteases, lipases, enterotoxins, gelatinases, elastases, among others (Rabaan, Gryllos, Tomas, & Shaw, 2001;Nam & John, 2007;Peixoto et al, 2012;Yadav, Verma, Pradhan, Dobriyal, & Sood, 2014).…”

QUALIDADE HIGIÊNICO-SANITÁRIA DE TAMBAQUI (Colossoma macropomum) COMERCIALIZADO NA CIDADE DE SÃO LUÍS - MA

“…Das cinco espécies de Aermonas identificadas, merece destaque a espécie A. hydrophila, pois frequentemente está associada à deterioração do pescado, além de ser de grande importância para a saúde pública. Segundo Peixoto et al (33) , espécies de A. hydrophila estão entre as cinco de grande relevância clínica, principalmente por serem patogênicas para os peixes e também para os seres humanos e por terem capacidade de produzir exotoxinas. Segundo Figueira et al (34) , peixes e outros frutos do mar podem se tornar fontes de contaminação para seres humanos devido ao fato de algumas vezes abrigarem espécies potencialmente patogênicas como, A. hydrophila, A. sobria, A. caviae e A. media.…”

Genetic markers for detection of Escherichia coli K-12 harboring ampicillin-resistance plasmid from an industrial wastewater treatment effluent pond

“…In addition, this work contributes to our understanding of antibiotic resistance in aquatic environments and the public health risks due to exposure to microorganisms in these environments. However, less attention is given to the aquatic environments than to the management and monitoring of the use of antibiotics (Watkinson et al, 2007a,b;Peixoto et al, 2012). In relation to the presence of Aeromonas spp, which are opportunistic pathogens, there are reports related to multi-resistance to antibiotics, among them from aquatic environments (Peixoto et al, 2012).…”

“…However, less attention is given to the aquatic environments than to the management and monitoring of the use of antibiotics (Watkinson et al, 2007a,b;Peixoto et al, 2012). In relation to the presence of Aeromonas spp, which are opportunistic pathogens, there are reports related to multi-resistance to antibiotics, among them from aquatic environments (Peixoto et al, 2012). Another bacterial genus identified was Chromobacterium spp, from which the most important species is the C. violaceum.…”