scholarly journals Comparative Pathogenicity of Aeromonas spp. in Cultured Red Hybrid Tilapia (Oreochromis niloticus × O. mossambicus)

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1192
Author(s):  
Mohamad Azzam-Sayuti ◽  
Md Yasin Ina-Salwany ◽  
Mohd Zamri-Saad ◽  
Salleh Annas ◽  
Mohd Termizi Yusof ◽  
...  
Keyword(s):  
Carbon Source ◽  
Freshwater Fish ◽  
Oreochromis Niloticus ◽  
Sole Carbon Source ◽  
Bacterial Suspension ◽  
Pathogenic Species ◽  
Histopathological Changes ◽  
Chronic Infections ◽  
Motile Aeromonas Septicaemia ◽  
Experimental Disease

The genus Aeromonas has been recognised as an important pathogenic species in aquaculture that causes motile Aeromonas septicaemia (MAS) or less severe, chronic infections. This study compares the pathogenicity of the different Aeromonas spp. that were previously isolated from freshwater fish with signs of MAS. A total of 124 isolates of Aeromonas spp. were initially screened for the ability to grow on M9 agar with myo-inositol as a sole carbon source, which is a discriminatory phenotype for the hypervirulent A. hydrophila (vAh) pathotype. Subsequently, LD50 of six selected Aeromonas spp. were determined by intraperitoneal injection of bacterial suspension containing 103, 105, and 107 CFU/mL of the respective Aeromonas sp. to red hybrid tilapias. The kidneys, livers and spleens of infected moribund fish were examined for histopathological changes. The screening revealed that only A. dhakensis 1P11S3 was able to grow using myo-inositol as a sole carbon source, and no vAh strains were identified. The LD50–240h of A. dhakensis 1P11S3 was 107 CFU/mL, while the non-myo-inositol utilizing A. dhakensis 4PS2 and A. hydrophila 8TK3 was lower at 105 CFU/mL. Similarly, tilapia challenged with the myo-inositol A. dhakensis 1P11S3 showed significantly (p < 0.05) less severe signs, gross and histopathological lesions, and a lower mortality rate than the non-myo-inositol A. dhakensis 4PS2 and A. hydrophila 8TK3. These findings suggested that myo-inositol utilizing A. dhakensis 1P11S3 was not a hypervirulent Aeromonas sp. under current experimental disease challenge conditions, and that diverse Aeromonas spp. are of concern in aquaculture farmed freshwater fish. Therefore, future study is warranted on genomic level to further elucidate the influence of myo-inositol utilizing ability on the pathogenesis of Aeromonas spp., since this ability correlates with hypervirulence in A. hydrophila strains.

Rhamnolipids stabilize quorum sensing mediated cooperation in Pseudomonas aeruginosa

2020 ◽  
Vol 367 (10) ◽  
Author(s):  
Rodolfo García-Contreras ◽  
Daniel Loarca ◽  
Caleb Pérez-González ◽  
J Guillermo Jiménez-Cortés ◽  
Abigail Gonzalez-Valdez ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Carbon Source ◽  
Public Goods ◽  
Sole Carbon Source ◽  
Regulatory Genes ◽  
Chronic Infections ◽  
Toxic Metabolites ◽  
Serial Cultivation ◽  
Selection Of

ABSTRACT Pseudomonas aeruginosa is one of the main models to study social behaviors in bacteria since it synthesizes several exoproducts, including exoproteases and siderophores and release them to the environment. Exoproteases and siderophores are public goods that can be utilized by the individuals that produce them but also by non-producers, that are considered social cheaters. Molecularly exoprotease cheaters are mutants in regulatory genes such as lasR, and are commonly isolated from chronic infections and selected in the laboratory upon serial cultivation in media with protein as a sole carbon source. Despite that the production of exoproteases is exploitable, cooperators have also ways to restrict the growth and selection of social cheaters, for instance by producing toxic metabolites like pyocyanin. In this work, using bacterial competitions, serial cultivation and growth assays, we demonstrated that rhamnolipids which production is regulated by quorum sensing, selectively affect the growth of lasR mutants and are able to restrict social cheating, hence contributing to the maintenance of cooperation in Pseudomonas aeruginosa populations.

The effect of vaccination in controling bacterial disease caused by Aeromonas hydrophila in nile tilapia (Oreochromis niloticus)

2014 ◽  
pp. 27
Author(s):  
Arne A Ratulangi ◽  
Reiny Tumbol ◽  
Hengky Manoppo ◽  
Henneke Pangkey
Keyword(s):  
Survival Rate ◽  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Bacterial Disease ◽  
Immersion Method ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Different Ages ◽  
Motile Aeromonas Septicaemia

This study aims to apply vaccination against bacterial disease. The purpose of vaccination is to trigger the immune respone both non-specific and specific of fish against bacteria Motile Aeromonas Septicaemia (MAS) caused by Aeromonas hydrophila. The vaccination for fish with different ages: 2-3 weeks and 5 weeks were done using immersion method. The fish were re-vaccinated (booster) after two weeks of the first vaccination. The survival rate was < 50 % for juveniles 2-3 weeks and > 50% for juveniles 5 weeks. Survival rate for juveniles 5 weeks was higher than juveniles of 2-3 weeks. This shows that organs of juveniles of 5 weeks were more complete than the 2-3 weeks juveniles. The age of fish is one of the important factors for successfully vaccination. Penelitian ini bertujuan untuk melakukan penerapan vaksinasi terhadap penyakit bakterial. Vaksinasi ditujukan untuk merangsang respon kekebalan non- spesifik dan spesifik pada tubuh ikan terhadap penyakit Motile Aeromonas Septicaemia (MAS) yang disebabkan oleh bakteri Aeromonas hydrophila. Vaksin diberikan pada benih ikan nila yang berbeda umur yaitu 2-3 minggu dan 5 minggu dengan menggunakan metode perendaman. Ikan divaksinasi ulang (booster) setelah 2 (dua) minggu dari vaksinasi yang pertama. Prosentase kelangsungan hidup < 50 % untuk benih umur 2-3 minggu dan > 50% untuk benih umur 5 minggu. Jumlah kematian benih umur 2-3 minggu lebih tinggi dari 5 minggu. Hal ini menunjukkan bahwa fungsi organ benih umur 5 minggu telah lebih lengkap dari pada benih umur 2-3 minggu. Umur ikan merupakan salah satu faktor penting penentu keberhasilan suatu kegiatan vaksinasi.

scholarly journals Pandrug-resistant Pseudomonas sp. expresses New Delhi metallo-β-lactamase-1 and consumes ampicillin as sole carbon source

2020 ◽  
Author(s):  
Vivek Kumar Ranjan ◽  
Shriparna Mukherjee ◽  
Subarna Thakur ◽  
Krutika Gupta ◽  
Ranadhir Chakraborty
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
New Delhi ◽  
Pseudomonas Sp

scholarly journals Study of a plugging microbial consortium using crude oil as sole carbon source

2008 ◽  
Vol 5 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Jing Wang ◽  
Guiwen Yan ◽  
Mingquan An ◽  
Jieli Liu ◽  
Houming Zhang ◽  
...  
Keyword(s):  
Carbon Source ◽  
Crude Oil ◽  
Sole Carbon Source ◽  
Microbial Consortium

scholarly journals Mutants affecting histidine utilization inAspergillus nidulans

1975 ◽  
Vol 25 (2) ◽  
pp. 119-135 ◽  
Author(s):  
Meryl Polkinghorne ◽  
M. J. Hynes
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Sole Carbon Source ◽  
Nitrogen Sources ◽  
Limiting Factor ◽  
Sole Nitrogen Source ◽  
Wild Type ◽  
Exogenous Substrate ◽  
Growth Properties ◽  
Type Strains

SUMMARYWild-type strains ofAspergillus nidulansgrow poorly onL-histidine as a sole nitrogen source. The synthesis of the enzyme histidase (EC. 4.3.1.3) appears to be a limiting factor in the growth of the wild type, as strains carrying the mutantareA102 allele have elevated histidase levels and grow strongly on histidine as a sole nitrogen source.L-Histidine is an extremely weak sole carbon source for all strains.Ammonium repression has an important role in the regulation of histidase synthesis and the relief of ammonium repression is dependent on the availability of a good carbon source. The level of histidase synthesis does not respond to the addition of exogenous substrate.Mutants carrying lesions in thesarA orsarB loci (suppressor ofareA102) have been isolated. The growth properties of these mutants on histidine as a sole nitrogen source correlate with the levels of histidase synthesized. Mutation at thesarA andsarB loci also reduces the utilization of a number of other nitrogen sources. The data suggest that these two genes may code for regulatory products involved in nitrogen catabolism. No histidase structural gene mutants were identified and possible explanations of this are discussed.

Description of Freshwater Fish Traditional Smoking in the Western Region, Cameroon

2021 ◽  
Vol 14 (1) ◽  
pp. 61-64
Author(s):  
Felix Meutchieye ◽  
Henri Grisseur Djoukeng ◽  
Youssouf Jamilou Ngouyamsa ◽  
Yacouba Manjeli
Keyword(s):  
Ethnic Group ◽  
Freshwater Fish ◽  
Oreochromis Niloticus ◽  
Clarias Gariepinus ◽  
Small Scale ◽  
African Catfish ◽  
Economic Activities ◽  
Fresh Fish ◽  
Hygiene Measures ◽  
Average Quantity

Western Cameroon is one of the regions most in needs of innovative and healthy solutions for freshwater fish conservation. This study aimed at evaluating the socio-economical characteristics of fish smokers and technical factors on the species smoked in the Noun Division. A total of 91 fish smokers were chosen. The socio-economic data were on age, gender, religion, number of dependents, marital status, ethnic group, education level, economic activities, smoking goals and workforce. The results of this study showed that fish smoking is practiced mainly by women (70%) which is common in Sub Sahara Africa small scale fish sector. The smokers are aged from 20 to 50 years (80%), married (92.2%) and taking care of a family of 1 to 10 persons (80%). These smokers are Muslim (74%), belonging to the Bamoun ethnic group (81%). They were also involved in other activities: agriculture (29%) and trade (1%). About 67% of the sampled smokers’ population had an experience of more than 10 years in the domain. The Purpose of smoking was largely sales (97%) and subsistence (3%). Nile tilapia (Oreochromis niloticus) was the most smoked species (36%), followed by African catfish (Clarias gariepinus) with a proportion of 32%. The average quantity of fresh fish smoked was 110 kg/day/smoker, with Oreochromis niloticus being more produced (60±4.74 kg/day/smoker). With regard to the smoking techniques used, hygiene measures were poorly respected. The major constraints revealed by the survey were that freshwater’s traditional fish smoking activities in Noun Division are influenced by gender, economic and cultural background. There is a lack of technical support material and financial means. Any implications for future investigations on health and food safety will be suitable for fresh fish smokers and the entire consumers.

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