Antibiotic and plasmid profiles of Aeromonashydrophila isolated from clinically infected freshwater fishes (Oreochromismossambicus, Puntiusgonionotus, Leptobarbushoevenii, Pangasiuspangasius, Anabas testudineus, Clariasgariepinus and Cichlasoma sp.)

Aeromonashydrophila is one of the most important aquatic pathogen affecting cultured and feral fishes worldwide. Disease infection resulted in million dollar loses to aquaculture. Antibiotic resistance is increasing among pathogenic bacteria due to the extensive and indiscriminate use of antibiotics and other chemotherapeutants in fish farms. The antibiotics and chemotherapeutants are used either to prevent or cure fish diseases. Both are employed as feed additives or dissolved directly into the water. In present study, it was found that A. hydrophilawas sensitive topeptidyltransferase and most of the aminoglycoside group, while it was resistance to β-lactams group. Present study provided an early warning of antibiotic resistance in A. hydrophila. Significantly, the Multiple Antibiotic Resistance (MAR) Index was 0.45. The current results indicated that the A. hydrophila in these farmed fish might have been indiscriminately and continuously exposed to those antibiotics during their culturing stages. The genetic determinants of antibiotic resistance are located extrachromosomaly and the ability to transfer the drug resistance was used to indicate the presence of R-Plasmids. Plasmids isolation was thus carried out from A. hydrophila. It was found that all of the A. hydrophila strains harboured plasmids. Constant monitoring should be done in order to obtain more information on antibiotic sensitivity of A. hydrophila and other known pathogenic aquatic bacteria species in order to avoid the development of antibiotic resistant superbug

Administration of β-glucan (Saccharomyces cerevisiae) by oral feeding increases survival, growth and immune responses in Oreochromis spp. infected with Aeromonashydrophila

The effects of feeding β-glucan on the survival and immune responses of Oreochromis spp. were investigated. Fish received 3% of (body weight of animal) commercial tilapia pellet diet containing β-glucanat the concentration of 25mg/kg twice a day until day 40th of experiment. Control fish were fed with normal commercial tilapia pellet diet without the test compound at the same schedule. Every 10 days of interval, the fish were weighed and their FCR were recorded. Blood samples were collected from each group on day 7th. Control and test fish were challenged by i.p injection of LD50 concentration of A. hydrophilaon day 41th. Daily mortality was recorded up to day 48th. Haemoglobin (Hb, g/L), packed cell volume (PCV, L/L), erythrocyte (RBCx1012/L), total leukocyte (x109/L), mortality and relative percentage survival (RPS) were determined and calculated. Feeding with 25mg/kg of β-glucan significantly enhanced the RPS and growth of the fish. Test fish injected with the compound also showed a significant increases in the total leukocytes count and Hb level (P <0.05), while there was no significant difference for PCV and RBC amounts. Administration of β-glucan through oral feeding effectively stimulates the immune response, growth and offers protection against A. hydrophila infection in Oreochromisspp. The results indicate that β-glucan could play an important role in the prevention of diseases in fish culture

Structural equation modelling of food safety knowledge, attitude and practices among consumers in Malaysia

Factors contributing to foodborne illnesses in Malaysia were identified as insanitary food handling procedures and lack of hygiene in food preparation area. Food safety at home is a critical point as consumers represent the final step in food preparation and prevention of foodborne diseases. This study aims to investigate the food safety knowledge, attitude and self-reported practices among consumers in Malaysia. An online survey was conducted, and data were analysed using descriptive statistics and exploratory factor analysis. A model linking food safety knowledge and attitude and their direct effects on practices were confirmed using structural equation modelling (SEM). The proposed model fulfilled the goodness of fit indices and is deemed acceptable. Respondents demonstrate good level of food safety knowledge and positive attitudes and self-reported practices. Food safety knowledge has a negative and insignificant relationship with food safety practices (β1 = -0.284, p>0.05) while attitude significantly affects food safety practices (β1 = 0.534, p<0.05). The findings clearly indicate that food safety knowledge does not directly affect food safety practices This is also the first study to provide new empirical findings on thermometer usage among consumers in Malaysia. This study establishes an important point of reference where consumers use visual appearances to determine if food is thoroughly cooked and practice washing raw chicken prior to cooking. Food safety practices at home play a critical role in protecting consumers in reducing risks of foodborne illnesses

FCFS-R5-067: Management of Knowledge Transfer Programme on Good Aquaculture Practices to Seabass Cage Culture Farmers in Tumpat, Kelantan

Seabass brackish water cage culture is a very profitable and challenging enterprise. However, the main problem of the culture is high mortality of fish due to factors such as improper management, water quality, environmental and diseases. The fish farming community in Laguna Sri Tujuh, Tumpat, Kelantan, has been continuously facing poor production of seabass due to high mortality of fish (fish kill) and poor aquaculture practices among fish farmers since the start of the cage culture in 2003. Knowledge transfer programme on good aquaculture practices (GAP) was initiated and undertaken by a group of researchers from Universiti Malaysia Kelantan (UMK) in January, 2016. Knowledge on GAP was transferred to the community through onsite training by using the Department of Fisheries (DOF) Malaysia seabass cage culture cluster project site as a model for this community. Guidance on water quality monitoring and methods on improving water quality were demonstrated. Important records such as daily mortality rate, feed consumption, fish stocks, and water physical properties were established. The farmers were taught on proper way of grading fish, feed and feeding management, proper waste disposal, prudent use of drugs, and use of immune enhancers as preventive medicine. In addition, Faculty of Veterinary Medicine, UMK also provides fish disease diagnostic services to the fish farmers. It is envisage that the seabass cage culture farmers who participated in this programme will be able to improve their production and raised their income by reducing fish mortality. The programme also aims to strengthen collaboration among fish farming community, DOF’s authority and researchers of UMK in promoting GAP for sustainable and profitable aquaculture. The programme will also produce a competent graduate intern with knowledge and technical skills in the brackish water cage culture, enhancing her employability in the aquaculture secto

Molecular characterisation of grouper iridovirus isolates from Peninsular Malaysia

Grouper Iriovirus (GIV) is one of the most devastating viral diseases of marine and cultured groupers worldwide. In the current study, 5 presumptive Malaysian GIV isolates were characterised through PCR amplification of the major capsid protein (MCP) gene and phylogenetic analysis of the sequences. The sequences from the five GIV isolates showed 100% homology with each other and a close relationship with grouper iridovirus isolate (GIV_Tn_352), which was clustered in group 1 together with King grouper iridovirus isolate (KGIV_Cy_346), Singapore grouper iridovirus (SGIV), and Crimson snapper iridovirus isolate (CSIV). The phylogenetic tree also showed different degree of relatedness with other Ranavirus strains which were obtained from the blast of GIV MCP gene in the NCBI database. This study confirmed the GIV isolates from Malaysia are related to other isolates that were reported previously

Antibiotics resistance of Vibrio spp. isolated from diseased seabass and tilapia in cage culture

Vibriosis has become one of the most important bacterial diseases in marine cultured organisms in recent years. This study was focusing on isolation and identification of Vibrio spp. isolated from diseased seabass (Lates calcarifer), tilapia (Oreochromis niloticus) and seawater from Sri Tujuh lagoon in East Coast of Malaysia; also determination of antibiotic resistance patterns among Vibrio spp. Vibrio species isolated from diseased seabass in Pantai Sri Tujuh, Tumpat, Kelantan were screened for their antibiotic sensitivity patterns by Kirby-Bauer method. A total of 47 isolates belonging to three different species were identified which are V. parahaemolyticus, V. vulnificus, and V. alginolyticus. In this study, high incidence of erythromycin, chloramphenicol and sulfamethoxazole resistance was observed among the Vibrio isolates, whereas all isolates were susceptible to oxytetracycline. Vibrio isolates were 96% resistant to one or more different classes of antibiotic, and 17 different resistance patterns were identified. The MAR index of 0.4 indicating the Vibrio spp. in these farmed fish might have been indiscriminately and continuously exposed to those antibiotics during culturing stages of the fish. This study showed that multidrug-resistant Vibrio spp. were common in diseased seabass and tilapia cultured at Sri Tujuh lagoon. These essential findings suggested involvement of seafood in transmission of these pathogen to human. In addition, oxytetracycline can be used as a treatment to combat vibriosis in diseased seabass and tilapia

Antibacterial activity and toxicity of Duckweed, Lemna minor L. (Arales: Lemnaceae) from Malaysia

Aims: New therapeutics are needed to ease the prevailing waterborne disease, and one of the alternatives is by exploring the natural compounds with antimicrobial properties. Duckweed, Lemna sp. is recorded as a medicinal herb that known to have antifungal and antibacterial activities towards several fungi and bacteria. Suitability of duckweed (Lemna minor) as an antibacterial resource against selected waterborne bacteria were evaluated in terms of its antibacterial activity and toxicity. Methodology and results: Antibacterial activity of the duckweed methanolic extract was tested against 11 selected waterborne bacteria using disc diffusion, minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) assay. Brine shrimp lethality assay was used to determine the toxicity of this extract. The lethal concentrations of plant extract resulting in 50% mortality of the brine shrimp (LC50) were then determined. Conclusion, significance and impact of study: Results showed that duckweed extract exhibited bacteriostatic and bactericidal against the selected bacteria activity at the concentration of MIC = 1.8-2.0 mg/mL and MBC ≥ 2.0 mg/mL. This study shows that methanolic extract of L. minor may contain bioactive compounds against bacteria and potential therapeutic effect. The crude extract is slightly toxic and may not safe to be used in high concentration but is valuable in further study as a potential antitumor agent

Antibiotics Resistance of Vibrio spp. Isolated from Diseased Seabass and Tilapia in Cage Culture

Vibriosis has become one of the most important bacterial diseases in marine cultured organisms in recent years. This study was focusing on isolation and identification of Vibrio spp. isolated from diseased seabass (Lates calcarifer), tilapia (Oreochromis niloticus) and seawater from Sri Tujuh lagoon in East Coast of Malaysia; also determination of antibiotic resistance patterns among Vibrio spp. Vibrio species isolated from diseased seabass in Pantai Sri Tujuh, Tumpat, Kelantan were screened for their antibiotic sensitivity patterns by Kirby-Bauer method. A total of 47 isolates belonging to three different species were identified which are V. parahaemolyticus, V. vulnificus, and V. alginolyticus. In this study, high incidence of erythromycin, chloramphenicol and sulfamethoxazole resistance was observed among the Vibrio isolates, whereas all isolates were susceptible to oxytetracycline. Vibrio isolates were 96% resistant to one or more different classes of antibiotic, and 17 different resistance patterns were identified. The MAR index of 0.4 indicating the Vibrio spp. in these farmed fish might have been indiscriminately and continuously exposed to those antibiotics during culturing stages of the fish. This study showed that multidrug-resistant Vibrio spp. were common in diseased seabass and tilapia cultured at Sri Tujuh lagoon. These essential findings suggested involvement of seafood in transmission of these pathogen to human. In addition, oxytetracycline can be used as a treatment to combat vibriosis in diseased seabass and tilapia

Antimicrobial polymers:The potential replacement of existing antibiotics?

Antimicrobial resistance is now considered a major global challenge; compromising medical advancements and our ability to treat infectious disease. Increased antimicrobial resistance has resulted in increased morbidity and mortality due to infectious diseases worldwide. The lack of discovery of novel compounds from natural products or new classes of antimicrobials, encouraged us to recycle discontinued antimicrobials that were previously removed from routine use due to their toxicity, e.g., colistin. Since the discovery of new classes of compounds is extremely expensive and has very little success, one strategy to overcome this issue could be the application of synthetic compounds that possess antimicrobial activities. Polymers with innate antimicrobial properties or that have the ability to be conjugated with other antimicrobial compounds create the possibility for replacement of antimicrobials either for the direct application as medicine or implanted on medical devices to control infection. Here, we provide the latest update on research related to antimicrobial polymers in the context of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens. We summarise polymer subgroups: compounds containing natural peptides, halogens, phosphor and sulfo derivatives and phenol and benzoic derivatives, organometalic polymers, metal nanoparticles incorporated into polymeric carriers, dendrimers and polymer-based guanidine. We intend to enhance understanding in the field and promote further work on the development of polymer based antimicrobial compounds

The effects of Vitex trifolia, Strobilanthes crispus and Aloe vera herbal-mixed dietary supplementation on growth performance and disease resistance in red hybrid tilapia (Oreochromis sp.)

Herbs and herb mixtures have been used as a growth promotant in livestock and aquaculture production. The objective of the study was to evaluate the effect of a dietary herbal mix comprised of Vitex trifolia (VTE), Strobilanthes crispus (SCE) and Aloe vera (AVE) on the growth performance, disease resistance and histology of Oreochromis sp. for 60 days. The fishes were divided into i) control, infected fish, fed with normal diet and infected fishes treated with different herbal-mixed supplementation diets of ii) VTE and SCE iii) SCE and AVE iv) AVE and VTE. All experimental groups were challenged using with Streptococcus agalactiae (1 × 107 cfu/mL) via intraperitoneal route on day 46. On day 46th (pre-challenge) and 60th (post-challenge), five fish were randomly chosen from each tank for each experimental and control groups to blood collection. The cumulative mortality and survival rate were assessed every day. Tissues from kidney, liver and spleen were examined. The fish supplemented with herbal-mix with the combination of VTE and SCE and AVE and VTE showed improved growth performance. For haematological assays, RBC, Hb, and WBC were higher (P<0.05) in fish supplemented with these herb mix, while the alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were significantly affected by mixed-herbal supplementation. Histopathological examination of the organs revealed no negative effects in tissues. In conclusion, this study suggested that methanolic extracts of herbal mix composed of V. trifolia, S. crispus and A. vera extracts were effective as growth promoters and bacterial disease treatment in Oreochromis sp. when supplemented in daily diet