Aquaculture Environment Research Articles

IR-based device to acquire real-time online heart ECG signals of fish (Cyprinus carpio) to evaluate the water quality

Water quality monitoring is a challenging task due to continuous pollution. The rapid development of engineering technologies has paved the way for the development of efficient and convenient computer-based online continuous water-quality assessment techniques. Techniques based on biological-responses are gaining attention, worldwide. Different biosensors have been developed in recent years to monitor real-time biological responses to evaluate water-quality. The survival and function of various organs of the organism depends on the cardiac system. Alterations in the cardiac system could signify the occurrence/initiation of stress in the organism. We developed a real-time online cardiac function assessment system-OCFAS to acquire fish ECG-signals. We obtained P-wave, R-wave, T-wave, PR-intervals, QT-intervals and QRS-complex continuously, which did not affect the normal activities of carp. We exposed Cyprinus carpio to different concentrations (National Environmental Quality Standards) of ammonia for 48 h. Our OCFAS has precisely acquired the required ECG-signals. A real-time dataset reveals sensitivity to ammonia in carp ECG-indexes. Compared with the control group the P-wave, R-wave and T-wave were weaker in ammonia-treated groups. In contrast, the PR-intervals, QT-intervals and QRS-complex were prolonged in the ammonia-treatment groups. The self-organizing map signifies that the PR-intervals, the QRS-complex and the QT-intervals are consistent with environmental stress. Linear regression analysis also quantitatively signifies that the PR interval has the highest R2 value and the lowest SSE-value, followed by the QRS complex and the QT interval. A concentration-related effect was observed in the ammonia treated groups. The integrated biomarker response (IBRv2) index was used to determine the overall stress of ammonia on carp heart ECG-indexes. IBRv2 also supports the real-time response of carp to ammonia stress. Ammonia levels in the aquaculture and water environment require special attention to avoid its adverse effects on the health of aquatic biota. Our study emphasizes the importance of online real-time fish ECG for water-quality assessment.

Aquaculture ecosystem microbiome at the water-fish interface: the case-study of rainbow trout fed with Tenebrio molitor novel diets

BackgroundSustainable aquaculture relies on multiple factors, including water quality, fish diets, and farmed fish. Replacing fishmeal (FM) with alternative protein sources is key for improving sustainability in aquaculture and promoting fish health. Indeed, great research efforts have been made to evaluate novel feed formulations, focusing especially on the effects on the fish gut microbiome. Few studies have explored host-environment interactions. In the present study, we evaluated the influence of novel insect-based (Tenebrio molitor) fish diets on the microbiome at the water-fish interface in an engineered rainbow trout (Oncorhynchus mykiss) farming ecosystem. Using 16S rRNA gene metabarcoding, we comprehensively analyzed the microbiomes of water, tank biofilm, fish intestinal mucus, fish cutis, and feed samples.ResultsCore microbiome analysis revealed the presence of a highly reduced core shared by all sample sources, constituted by Aeromonas spp., in both the control and novel feed test groups. Network analysis showed that samples were clustered based on the sample source, with no significant differences related to the feed formulation tested. Thus, the different diets did not seem to affect the environment (water and tank biofilm) and fish (cutis and intestinal mucus) microbiomes. To disentangle the contribution of feed at a finer scale, we performed a differential abundance analysis and observed differential enrichment/impoverishment in specific taxa, comparing the samples belonging to the control diet group and the insect-based diet group.ConclusionsOmic exploration of the water-fish interface exposes patterns that are otherwise undetected. These data demonstrate a link between the environment and fish and show that subtle but significant differences are caused by feed composition. Thus, the research presented here is a step towards positively influencing the aquaculture environment and its microbiome.

Temporal stability and assembly mechanisms of gut microbiota in sea cucumbers response to nanoplastics treatment

Aquaculture provides essential food for humans, and the health of farmed species is particularly important for the aquaculture industry. Aquaculture environment could be a sink of plastic debris (PDs) due to the enclosed character and heavy use of plastics. Gut microbiota of aquaculture species could respond to the exogenous pollutants and regulate the health of hosts. Here, variations in gut microbiota of Apostichopus japonicus induced by the ingested nanoplastics (NPs) were investigated by a lab experiment. We selected a NPs concentration gradient of 100 mg/kg and 500 mg/kg to simulate microplastic pollution to A. japonicus, and the significant differences in gut microbiota composition after 21 days of NP exposure were evaluated. According to the high-throughput sequencing from time series samples, a decrease of diversity in gut microbiota of A. japonicus with dietary NPs was observed. In addition, the gut microbiota compositions of sea cucumbers with and without NPs exposure were also distinct, expressing as enrichment of Bacteroidota while reducement of Proteobacteria under NPs stresses. Combined the results of network analysis, the less complexity and stability of gut microbiota in sea cucumbers with dietary NPs were proved. Based on the neutral community model, the ingested NPs elevated the contribution of stochastic processes for the gut microbiota assembly in sea cucumbers. Our study showed that substantial variations in gut microbiota of A. japonicus under NPs stresses, and also explored the underlying mechanisms regulating these changes. This research would offer new meaningful insights into the toxicity of NPs on sea cucumbers, contributing a solid fundament to improve the health of sea cucumbers under NPs stresses.

Aquaculture defects recognition via multi-scale semantic segmentation

Aquaculture net pen defects such as biofouling, vegetation, and holes are key challenges to efficient and sustainable fish production in aquaculture. These defects must be monitored to avoid problems with aquaculture net safety as well as fish growth. Recently, deep learning methods have been adopted to solve detection and classification problems in different applications. However, the conventional methods are challenging to meet the demands of high precision and real-time detection of aquaculture net defects in a complex marine environment. Towards this end, this paper proposes an autonomous net pen defect detection system that contains a novel multi-scale semantic segmentation topology for detecting the biofouling, vegetation, and hole problems in the aquaculture environment. In particular, we emphasize fusing the attention maps obtained across different decomposition levels of the network to generate rich feature distributions that enable the accurate extraction of biofouling, vegetation, and holes within aquaculture nets. Moreover, the proposed model is thoroughly tested on two private datasets and two public datasets which were acquired from a real-field fish farms. Across all four datasets, the proposed framework showed remarkable biofouling, vegetation, and hole detection performance, where it outperformed state-of-the-art methods by 6.58%, 3.69%, 6.44%, and 4.78% in terms of mean average precision across LABUST, KU, NDv1, and NDv2 datasets, respectively.

Bacterial community succession and the enrichment of antibiotic resistance genes on microplastics in an oyster farm

Microplastics can be colonized by microorganisms and form plastisphere. However, knowledge of bacterial community succession and the enrichment of antibiotic resistance genes (ARGs) and pathogens on microplastics in aquaculture environments is limited. Here, we conducted a 30-day continuous exposure experiment at an oyster farm. Results showed that the alpha-diversity of communities on most microplastics continuously increased and was higher than in planktonic communities after 14 days. Microplastics could selectively enrich certain bacteria from water which can live a sessile lifestyle and promote colonization by other bacteria. The composition and function of plastisphere communities were distinct from those in the surrounding water and influenced by polymer type and exposure time. Microplastics can enrich ARGs (sul1, qnrS and blaTEM) and harbor potential pathogens (e.g., Pseudomonas aeruginosa). Therefore, microplastic pollution may pose a critical threat to aquaculture ecosystems and human health. Our study provides further insight into the ecological risks of microplastics.

Snapshot of resistome, virulome and mobilome in aquaculture

Aquaculture environments can be hotspots for resistance genes through the surrounding environment. Our objective was to study the resistome, virulome and mobilome of Gram-negative bacteria isolated in seabream and bivalve molluscs, using a WGS approach. Sixty-six Gram-negative strains (Aeromonadaceae, Enterobacteriaceae, Hafniaceae, Morganellaceae, Pseudomonadaceae, Shewanellaceae, Vibrionaceae, and Yersiniaceae families) were selected for genomic characterization. The species and MLST were determined, and antibiotic/disinfectants/heavy metals resistance genes, virulence determinants, MGE, and pathogenicity to humans were investigated. Our study revealed new sequence-types (e.g. Aeromonas spp. ST879, ST880, ST881, ST882, ST883, ST887, ST888; Shewanella spp. ST40, ST57, ST58, ST60, ST61, ST62; Vibrio spp. ST206, ST205). >140 different genes were identified in the resistome of seabream and bivalve molluscs, encompassing genes associated with β-lactams, tetracyclines, aminoglycosides, quinolones, sulfonamides, trimethoprim, phenicols, macrolides and fosfomycin resistance. Disinfectant resistance genes qacE-type, sitABCD-type and formA-type were found. Heavy metals resistance genes mdt, acr and sil stood out as the most frequent. Most resistance genes were associated with antibiotics/disinfectants/heavy metals commonly used in aquaculture settings. We also identified 25 different genes related with increased virulence, namely associated with adherence, colonization, toxins production, red blood cell lysis, iron metabolism, escape from the immune system of the host. Furthermore, 74.2 % of the strains analysed were considered pathogenic to humans. We investigated the genetic environment of several antibiotic resistance genes, including blaTEM-1B, blaFOX-18, aph(3″)-Ib, dfrA-type, aadA1, catA1-type, tet(A)/(E), qnrB19 and sul1/2. Our analysis also focused on identifying MGE in proximity to these genes (e.g. IntI1, plasmids and TnAs), which could potentially facilitate the spread of resistance among bacteria across different environments. This study provides a comprehensive examination of the diversity of resistance genes that can be transferred to both humans and the environment, with the recognition that aquaculture and the broader environment play crucial roles as intermediaries within this complex transmission network.

The Effectiveness of Lactic Acid Bacteria on the Immune System of Vannamei Shrimp Infected with Bacteria Vibrio Parahaemolyticus

Diseases are a major obstacle in shrimp farming because they can cause relatively high mortality and decrease the quality of the aquaculture environment. One dangerous shrimp disease is caused by Vibrio bacteria. Today, people are turning to biological control methods by utilizing lactic acid bacteria that live as microflora in the digestive tract of aquaculture animals. This study aimed to analyze the potential of lactic acid bacteria isolates from the gut of vannamei shrimp as probiotic candidates and to analyze selected lactic acid bacteria isolates that were effective in increasing the immune response and survival of vannamei shrimp infected with Vibrio parahaemolyticus bacteria. Four BAL isolates were isolated, designated as 8A, 11B, F1, and G2. BAL isolates showed antibacterial activity against Vibrio parahaemolyticus bacteria with an inhibition zone of up to 11.5 mm, capable of living at acidic to alkaline pH (1.5-7.2), bile salts (3000 ppm) and negative catalase. The characterization of several tests such as gram-positive, inhibition test and sugar fermentation test and comparison of LAB characterization showed that LAB isolates (G2) from the intestine of vannamei shrimp were classified as Pediococcus acidilactici. The application of probiotics, namely LAB (G2) to vannamei shrimp through feed can stimulate the vaname shrimp immune system after being challenged with V. parahaemolyticus, as indicated by an increase in the number of hemocytes (THC), phagocytosis activity, and suppressing the population of V. parahaemolyticus in vannamei shrimp.

Colistin Resistance in Aquaculture Environment: An Emerging Challenge

AbstractThe emergence of colistin resistance is one of the most serious future issues since it is a last‐resort antibiotic used to treat infections caused by multidrug‐resistant (MDR) gram‐negative bacteria, particularly those resistant to carbapenems. The aquatic environment acts as a reservoir for the emergence and spread of colistin resistant pathogens. The emergence and transmission of a plasmid mediated mcr gene is one of the most important mechanism of colistin resistance in gram negative bacteria. Several mcr variants have been identified in zoonotic pathogens of aquatic origin that may easily transmit this gene to human pathogens. Currently, very few studies have been conducted to test colistin susceptibility in aquaculture associated bacteria. This may be attributed to a limited technical resource for screening colistin‐resistant microorganisms. As a result, to reduce the emergence and spread of colistin resistance in human and animal health, as well as in the environment, the One Health strategy and laboratory methodologies must be expanded.

A method for detecting uneaten feed based on improved YOLOv5

In order to increase feed utilization and reduce rearing costs, it is crucial to accurately detect remaining pellets in real-time and optimize feeding mechanisms for precise feeding in intensive aquaculture. Machine vision and acoustic methods, which are widely used for the detection of residual particles, fail to adequately address scenarios such as the detection of overlapping, conjoined, faraway and dense particles, as well as particles with interference from water surface ripples and fish motion. To address these issues, this paper proposed a model for uneaten feed detection based on You Only Look Once (YOLO)-v5 network, which was built as follows: (1) The last C3 module of the backbone network is introduced into the coordinated attention (CA) mechanism, which evolves into a coordinated feature attention extraction (CFAE) module to obtain global information. (2) The GSConv module, and the VoVGSCSP module which was the aggregative mode of GSConv module, were adopted in the neck network part. (3) The shallow feature map was spliced with the deep feature map, and the tiny target detection layer (DL) was added for detection. The model elucidates the true condition of the detected residual particles by enhancing detection accuracy and minimizing model complexity, enabling precise and rapid identification of the pellet. This article employs seven sets of data to conduct a comparative analysis of the outcomes achieved before and after enhancing the three major components of the network. The experimental results showed that the YOLOv5s-CAGSDL model achieved an accuracy of 94.1% for feed particles detection, effectively solving the above problems in the actual rearing environment. Meanwhile, compared with the YOLOv5s model, AP50and FPS of the YOLOv5s-CAGSDL model were increased by 6.30% and 10.80% respectively, bringing potential environmental and economic benefits in the actual aquaculture environment. The source codes and datasets are available at: https://github.com/AAAArmstrong/YOLOv5s-CAGSDL.

A fish image segmentation methodology in aquaculture environment based on multi-feature fusion model

Underwater fish image processing is one of the key technologies to realize intelligent aquaculture. However, due to the complexity of marine environments, underwater fish images usually have the characteristics of color cast, unbalanced contrast, and blur. Current underwater fish image segmentation methods lack adaptive models and have low segmentation accuracy. Hence, this paper constructs a convolutional neural network-based image segmentation model. This paper first proposes a fish image preprocessing method based on pixel threshold segmentation. To enhance the important features in a fish image, this method uses the minimum Euclidean distance between the original image peaks to redefine the threshold and fuses the thresholded image with the original image. Second, to strengthen the extraction of high-level semantic features of images, the multiscale attentional feature extraction module (MAFEM), which fuses the adaptive channel attention mechanism with the hybrid dilated convolutional pyramid pooling module, is proposed. In this paper, a data set in voc format is produced based on underwater fish images, and this data set is used to verify the model in this paper. The mean intersection over union (MIoU) reaches 92.6%. Compared with other traditional segmentation models, the MIoU, mean pixel accuracy (MPA), and balanced F score (F1-score) of the segmentation results of the model in this paper are increased by averages of 1.84%, 0.785%, and 1.18%, respectively. The experimental results show that this model has a better segmentation effect than other models and provides a theoretical basis for intelligent monitoring of underwater fish body length measurement, weight estimation, and discrimination of growth and health statuses.

The relationship between the surface color and astaxanthin concentration of different fillet parts of Atlantic salmon under mariculture and freshwater farming modes

The cultivate method has a significant impact on the quality of fish, such as the accumulation of nutritive substances, the surface glossiness and so on. Comparison of surface color profile and astaxanthin (AST) accumulation in Atlantic salmon between marian and freshwater was systematically discussed in this study. Mariculture was much easier to accumulate color than the freshwater farming. Meanwhile, regardless of aquaculture environment, different muscle parts of Atlantic salmon showed various chromaticity value. And the dorsal muscle was the best one, followed by the tail and abdomen. Specifically, AST content was determined. An orthogonal experiment, L9(33), was applied to optimize the extraction conditions. Under optimized conditions, AST concentration reached 15.56 μg/g, an 80.51 % increase than before. Interestingly, color value was not positively correlated with AST concentration in various muscle parts of the same fish. Compared to the dorsal part, the tail part showed lower color and higher AST content. However, the AST content in mariculture was higher than that in freshwater farming overall. These results provided a better understanding of the relationship between color and AST concentration in Atlantic salmon.

Occurrence of digenean parasites in freshwater snails in the Murrumbidgee catchment area, Australia

Freshwater snails are important hosts in the life cycles of many medically important parasites, particularly for digenetic trematodes such as liver flukes and schistosomes. The current study was conducted to determine the infection of freshwater snails with parasites that can potentially be transmitted to humans within the Murrumbidgee catchment area which is an area of widespread intensive aquaculture in Australia. A total of 116 freshwater snails, belonging to three species (Isidorella hainesii, Glyptophysa novaehollandica and Bullastra lessoni), were examined for the presence of parasites in both man-made and natural environments. The analysis of sequence data, including the internal transcribed spacers (ITS) of nuclear ribosomal DNA, small subunit (18S) ribosomal DNA, and large subunit (28S) ribosomal DNA, indicated that the collected parasites belonged to two distinct genera, namely Clinostomum and Echinostoma. It is noteworthy that species of both of these digenean parasites have the potential to be zoonotic. Cercariae of both Clinostomum and Echinostoma were observed in snails collected from aquaculture settings. It is important to highlight that infectious stages of Clinostomum has been previously detected in edible fish within Australia. This information raises concerns regarding the potential transmission of these parasites to humans through the consumption of contaminated fish. These findings emphasize the importance of monitoring and controlling the presence of Clinostomum and Echinostoma in aquaculture environments to minimise the risk of zoonotic infections and ensure food safety. Further research and surveillance are needed to better understand the prevalence, transmission dynamics, and potential public health implications associated with these parasites in the context of aquaculture in Australia.

Editorial: Aquaculture environment regulation and system engineering

Editorial: Aquaculture environment regulation and system engineering

In-situ SERS detection of quinolone antibiotic residues in aquaculture water by multifunctional Fe3O4@mTiO2@Ag nanoparticles

Antibiotic residues in aquaculture environments disrupt the ecosystem balance and pose a potential hazard to human health when entering the food chain. Therefore, ultra-sensitive detection of antibiotics is necessary. In this study, a multifunctional Fe3O4@mTiO2@Ag core–shell nanoparticle (NP), synthesized using a layer-by-layer method, was demonstrated to be useful as an enhanced substrate for in-situ surface-enhanced Raman spectroscopy (SERS) detection of various quinolone antibiotics in aqueous environments. The results showed that the minimum detectable concentrations of the six investigated antibiotics were 1 × 10−9 mol/L (ciprofloxacin, danofloxacin, enoxacin, enrofloxacin, and norfloxacin) and 1 × 10−8 mol/L (difloxacin hydrochloride) under the enrichment and enhancement of Fe3O4@mTiO2@Ag NPs. Additionally, there was a good quantitative relationship between the antibiotics concentrations and SERS peak intensities within a certain detection range. The results of the spiked assay of actual aquaculture water samples showed that the recoveries of the six antibiotics ranged from 82.9% to 113.5%, with relative standard deviations ranging from 1.71% to 7.24%. In addition, Fe3O4@mTiO2@Ag NPs achieved satisfactory results in assisting the photocatalytic degradation of antibiotics in aqueous environments. This provides a multifunctional solution for low concentration detection and efficient degradation of antibiotics in aquaculture water.

Changes in the liver of Tinca tinca under successive domestication using an integrated multi-omics approach

Domestication is the process of modifying the phenotype of a population through anthropic selection from human perspectives. Successive generations of domestication have influenced the physiological characteristics of tench Tinca tinca. In current study, we investigated gene and protein expression alterations in the liver of fifth-generation (F5). A total of 420 genes were found to be upregulated and 351 genes were downregulated, while 410 proteins were upregulated and 279 proteins were downregulated in domesticated T. tinca (DT). The integrated analysis of omics data revealed a total of 55 genes/proteins exhibiting consistent upregulation and 12 genes/proteins displaying consistent downregulation in DT. The upregulated genes/proteins in DT, such as SSR1, DERLIN2, OS9, DNAJB11, and HYOU1, exhibit enrichment in the protein processing in the endoplasmic reticulum pathway. Additionally, upregulated genes/proteins such as IL2RB, F13B, and IRF3 are associated with immune response. Conversely, downregulated genes/proteins in DT, including HSD11B1, CYP24A1, and COMT, play roles in hormone metabolism. These findings indicate that domestication can have a substantial impact on the physiological modifications related to protein processing, immune response, and hormone metabolism in DT. These adaptations potentially enhance their ability to thrive in artificial aquaculture environments, leading to improved growth and development. The exploration of genetic changes in DT will not only improve aquaculture practices but also provide significant insights into the broader process of domestication and its effects on physiological functions.

Environmental irradiance and nitrogen source variability trigger the intracellular carbon and nitrogen reallocation of Gracilariopsis lemaneiformis (Rhodophyta)

A rhodophyte Gracilariopsis lemaneiformis is widely cultivated for food, carbon sequestration and bioproducts, and commonly experiences changing irradiance levels and nitrogen sources that might influence the productivity and biochemical composition of the alga. To explore optimal culture conditions or manipulations to gain best yield of carbohydrates and amino acids of G. lemaneiformis during mariculture, we cultured G. lemaneiformis in four conditions including high irradiance and low irradiance coupled with nitrate and ammonium (denoted as HI-NO3−, LI-NO3−, HI-NH4+ and LI-NH4+). The results showed that irradiance, nitrogen source and their interactions significantly regulated the intracellular carbon and nitrogen metabolism of G. lemaneiformis and the influence of irradiance was greater than of nitrogen source. High irradiance promoted more carbon accumulation of G. lemaneiformis, which was confirmed by higher growth rate, net photosynthesis rates and contents of soluble carbohydrate, carbon and C/N ratios. In contrast, low irradiance is conductive to nitrogen accumulation, as revealed by high contents of nitrogen, phycoerythrin, soluble protein and amino acids. Furthermore, we found nitrate coupled with high irradiance significantly promoted carbon sequestration of G. lemaneiformis, and the ammonium combined with low irradiance significantly promoted nitrogen assimilation and transformation. In addition, arginine exhibited a higher nitrogen storage capacity than phycoerythrin, as evidenced by the higher content of arginine and correspondingly higher nitrogen reserves in G. lemaneiformis under low light coupled with ammonium and nitrogen- enriched environments. Moreover, the content of proline was higher under low irradiance conditions, but its proportion among the eighteen free amino acids was upregulated by high irradiance, indicating its important role in responding to high-light aquaculture environments. These findings demonstrate that irradiance and nitrogen source influence the carbon and nitrogen reallocation of G. lemaneiformis and that the combination of these two variables can induce the production of chemical products for biotechnological, aquaculture, and nutraceutical industry.

Trends in and Future Research Direction of Antimicrobial Resistance in Global Aquaculture Systems: A Review

The accelerated development of antibiotic resistance genes (ARGs) and antimicrobial resistance (AMR) in aquaculture environments due to the overuse of antibiotics is a global concern. To systematically understand the research trends in and key concepts of ARGs and AMR in aquaculture systems, this study employed the bibliometrix R-package to conduct a bibliometric analysis of the publication characteristics of ARGs and AMR in aquaculture systems from the Web of Science, published from 2000 to 2021. The results revealed that China has produced the most papers. China and the northern hemisphere countries work closely together. Collaboration and multidisciplinary research helped to better understand the impact of AMR in aquaculture on food security and human health. Antibiotic-resistant bacteria and ARGs in aquaculture, as well as the relationship between water environmental variables, antibiotic residuals, and ARGs, are the current research focus. One of the future directions is to establish a conclusive link among water environmental variables, antibiotics, and ARGs. Another future direction is the development of new economical and environmentally friendly technologies to treat AMR in aquaculture wastewater. Collectively, our findings investigate the development directions of AMR research in global aquaculture systems and provide future perspectives.

Anomaly Detection on Univariate Sensing Time Series Data for Smart Aquaculture Using Deep Learning

Abstract Aquaculture plays a significant role in both economic development and food production. Maintaining an ecological environment with good water quality is essential to ensure the production efficiency and quality of aquaculture. Effective management of water quality can prevent abnormal conditions and contribute significantly to food security. Detecting anomalies in the aquaculture environment is crucial to ensure that the environment is maintained correctly to meet healthy and proper requirements for fish farming. This article focuses on the use of deep learning techniques to detect anomalies in water quality data in the aquaculture environment. Four deep learning anomaly detection techniques, including Autoencoder, Variational Autoencoder, Long-Short Term Memory Autoencoder, and Spectral-Residual Convolutional Neural Network, were analysed using multiple real-world sensor datasets collected from IoT aquaculture systems. Extensive experiments were conducted for temperature, dissolved oxygen, and pH parameters, and the evaluation analysis revealed that the Long-Short Term Memory Autoencoder anomaly detection method showed promising results in detecting anomalies for the temperature and oxygen datasets, while the Spectral-Residual Convolutional Neural Network demonstrated the best performance on the pH datasets.

Aquaculture environment changes fish behavioral adaptability directly or indirectly through personality traits: a case study

Aquaculture environment changes fish behavioral adaptability directly or indirectly through personality traits: a case study

Prevalence and antibiotic resistant Escherichia coli isolated from abattoir and aquaculture environment in Ebonyi State, South East Nigeria.

Background: The present study was carried out to evaluate the distribution and antibiotics profile of Escherichia coli from abattoir and aquaculture.Methods: Abattoir and aquaculture effluents were randomly collected from various parts of Abakaliki in Ebonyi State. Bacterial detection was conducted using cultural and biochemical analysis. Susceptibility of the E. coli to antimicrobials was investigated using the Kirby- Bauer disk diffusion method.Results: The microbial load from abattoirs ranges from 0.26±0.11x107 to 4.08±0.11x107 cfu/ml and aquacultures 0.40±0.04x107 to 4.06±2.74x107 cfu/ml differ significantly (P<0.05). Out of the total 44 E. coli isolates from abattoir, drainage shows the highest E. coli isolates (40.9 %) and waste water least (22.7 %), while of the 18 E. coli isolates from aquaculture, 55.6 % were from concrete pond, while 44.4 % were from earthen pond. The E. coli isolates showed reasonable susceptibility to cefeprime (62.5 %), followed by imipenem (50. 0 %). However, all the E. coli isolates were resistant to amoxicillin/clavulanic acid, cefixime, cefotaxime and tobramycin. E. coli MAR index range from 0.4 - 0.9.Conclusion: The high microbial load, antibiotic resistance and higher MAR index >2 is of public health concern and further demonstrates the need for adequate treatment and disposal of waste generated from abattoir and aquaculture.