Pathogenic Bacteria in Oreochromis Niloticus Var. Stirling Tilapia Culture

Abstract

Tilapia Oreochromis niloticus is an aquaculture resource that represents one of the most popular crops in the world. However, species cultivation presents health problems, which are associated with the presence of pathogenic bacteria and causes high economic losses. The aim of this study was to determine the diversity of these bacteria at the genus level in the species O. niloticus var. Styrling during growing stage in the fattening and pre-fattening phases. Tilapia samples were collected and analyzed; each sample was subjected to a macroscopic external and internal observation of organs and tissues. Subsequently, samples were evaluated by microbiological tests using Trypticase Soy Agar (TSA), Thiosulfate Citrate Bile Salts Sucrose Agar (TCBS) and selective media (Pseudomonas sp. Group), and conventional biochemical tests aimed at the production of glucose, sucrose, lactose, oxidase, catalase, indole, ornithine and Gram staining. External analysis revealed clinical signs of disease such as skin bleeding, body ulceration, corneal opacity, and intestine and vesicle inflammation. Microbiological and biochemical analysis showed the presence of eleven bacterial genera known as Arthrobacter sp., Enterococcus sp., Staphylococcus sp., Micrococcus sp., Streptococcus sp., Aeromonas sp., Pseudomonas sp., Edwardsiella sp., Flexibacter sp. and Flavobacterium sp., with a predominance of 55% Gram-negative bacilli in tilapia crops. According to the results, it is necessary to take preventive and corrective measures in order to avoid possible risks during production cycles, mainly when handling organisms. It is also important to promote good crop management practices and quality systems in production units to benefit the aquaculture sector.

Molecular identification of Streptococcus sp. and antibiotic resistance genes present in Tilapia farms (Oreochromis niloticus) from the Northern Pacific region, Costa Rica

“…This could be explained because aquaculture environments have been described as reservoirs of ARGs, due to the constant application of antibiotics (Harnisz et al 2015) and the presence of other opportunistic bacteria such as Flavobacterium columnare, Edwardsiella sp. (Huicab-Pech et al 2017), Aeromonas sp. (Liu et al 2020), Francisella sp.…”

Prevalence and Antibiogram of Vibrio parahaemolyticus and Aeromonas hydrophila in the Flesh of Nile Tilapia, with Special Reference to Their Virulence Genes Detected Using Multiplex PCR Technique

“…In general, seafood is a notable source of pathogenic microorganisms infectious to humans [5,6]. Cultivation of fish may pose some fish health problems due to contamination by pathogenic bacteria, which leads to high economic Antibiotics 2021, 10, 654 2 of 16 losses [7]. Contamination can occur at any time during the collection, storage or distribution of seafood and may come from water, facilities, machinery and handlers.…”

The effect of dietary honey prebiotic on microbiota diversity in the digestive tract of Nile tilapia (Oreochromis niloticus) and its growth performance

“…The Nile tilapia is one of the generally cultured commodities around the world and the most investigated in terms of aquaculture (Food and Agriculture Organization (FAO) of the United Nations, 2017). Emerging as the major commodity of aquaculture in most parts of the world due to being an easily cultured species, the Nile tilapia can adapt well to various environmental conditions, tolerate high stocking density (Pech et al., 2016), grow at a rapid rate, easily accept natural diets and diet supplements, and have disease resistance (Pech et al., 2017). As much as 72% of Nile tilapia total production in the world is yielded in Southeast Asia (Ye et al., 2011).…”