Aeromonas caviae alters the activities of ecto-enzymes that hydrolyze adenine nucleotides in fish thrombocytes

Use of Probiotic Bacteria and Bacteriocins as an Alternative to Antibiotics in Aquaculture

In addition to their use in human medicine, antimicrobials are also used in food animals and aquaculture, and their use can be categorized as therapeutic against bacterial infections. The use of antimicrobials in aquaculture may involve a broad environmental application that affects a wide variety of bacteria, promoting the spread of bacterial resistance genes. Probiotics and bacteriocins, antimicrobial peptides produced by some types of lactic acid bacteria (LAB), have been successfully tested in aquatic animals as alternatives to control bacterial infections. Supplementation might have beneficial impacts on the intestinal microbiota, immune response, development, and/or weight gain, without the issues associated with antibiotic use. Thus, probiotics and bacteriocins represent feasible alternatives to antibiotics. Here, we provide an update with respect to the relevance of aquaculture in the animal protein production sector, as well as the present and future challenges generated by outbreaks and antimicrobial resistance, while highlighting the potential role of probiotics and bacteriocins to address these challenges. In addition, we conducted data analysis using a simple linear regression model to determine whether a linear relationship exists between probiotic dose added to feed and three variables of interest selected, including specific growth rate, feed conversion ratio, and lysozyme activity.

Bacteriological, Clinical and Virulence Aspects of Aeromonas-associated Diseases in Humans

Aeromonads have been isolated from varied environmental sources such as polluted and drinking water, as well as from tissues and body fluids of cold and warm-blooded animals. A phenotypically and genotypically heterogenous bacteria, aeromonads can be successfully identified by ribotyping and/or by analysing gyrB gene sequence, apart from classical biochemical characterization. Aeromonads are known to cause scepticemia in aquatic organisms, gastroenteritis and extraintestinal diseases such as scepticemia, skin, eye, wound and respiratory tract infections in humans. Several virulence and antibiotic resistance genes have been identified and isolated from this group, which if present in their mobile genetic elements, may be horizontally transferred to other naive environmental bacteria posing threat to the society. The extensive and indiscriminate use of antibiotics has given rise to many resistant varieties of bacteria. Multidrug resistance genes, such as NDM1, have been identified in this group of bacteria which is of serious health concern. Therefore, it is important to understand how antibiotic resistance develops and spreads in order to undertake preventive measures. It is also necessary to search and map putative virulence genes of Aeromonas for fighting the diseases caused by them. This review encompasses current knowledge of bacteriological, environmental, clinical and virulence aspects of the Aeromonas group and related diseases in humans and other animals of human concern.