The antibacterial activity of erythrocytes from Clarias fuscus associated with phagocytosis and respiratory burst generation

ABSTRACTThe objectives of this study were to investigate the antibacterial activity of G. verrucosa extract in test inhibitory zone with different concentrations (500, 1000, 1500, and 2000 mg/L) and to examine G. verrucosa extract with different dosage (0.5, 1.0, 1.5, 2.0 g/kg) in feed on immune responses (total hemocytes count, phagocytic activity, phenoloxidase activity, respiratory burst) and survival rate in the Litopenaeus vannamei against the pathogenic Vibrio harveyi. Pacific white shrimp with an initial body weight of 5.25±0.55 g was reared in the aquarium (60×30×30 cm3) with a density of 10 shrimp/aquarium. Pacific white shrimp had been fed three times a day as much as 3% in at satiation for 14 days after challenged with V. harveyi. The first results of the inhibitory test showed that all the concentration of G. verrucosa extract was able to inhibit the growth of V. harveyi and the second result showed that the extract of G. verrucosa can increase the immune responses of shrimp. In the result of survival showed that shrimp fed with 0.5, 1.0, 1.5, and 2.0 g/kg has 80, 73, 70, and 70%, respectively. In conclusion, the seaweed extract of G. verrucosa has antibacterial activity and can induce the immune responses and resistance of Pacific white shrimp against V. harveyi infection.Keywords: Gracilaria verrucosa, seaweed, Vibrio harveyi, vibriosis, Litopenaeus vannamei ABSTRAKTujuan dari penelitian ini adalah untuk menguji aktivitas antibakteri ekstrak G. verrucosa dalam uji zona hambat dengan konsentrasi yang berbeda (yaitu 500, 1000, 1500, dan 2000 mg/L) dan studi perlakuan pengobatan untuk menguji ekstrak G. verrucosa pada pakan dengan dosis yang berbeda (yaitu 0,5; 1,0; 1,5; dan 2,0 g/kg) pada respons imun (yaitu jumlah total hemosit, aktivitas fagositik, aktivitas fenoloksidase, respiratory burst) dan tingkat kelangsungan hidup pada udang vaname terhadap bakteri patogen Vibrio harveyi. Udang vaname dengan berat badan awal 5,25 ± 0,55 g dipelihara di akuarium (60 × 30 × 30 cm3) dengan kepadatan 10 udang/akuarium. Udang vaname pasifik diberi makan tiga kali sehari 3% at satiation selama 14 hari setelah di uji tantang V. harveyi. Hasil pertama dari uji zona hambat menunjukkan bahwa semua konsentrasi ekstrak G. verrucosa mampu menghambat pertumbuhan V. harveyi dan hasil kedua menunjukkan bahwa pemberian ektrak G. verrucosa dapat meningkatkan respon imun udang. Hasil tingkat kelangsungan hidup menunjukkan bahwa perlakuan pakan udang dengan dosis 0,5; 1,0; 1,5; dan 2,0 g/kg memiliki tingkat kelangsungan hidup masing-masing 80, 73, 70, dan 70%. Kesimpulannya, ekstrak rumput laut G. verrucosa memiliki aktivitas antibakteri dan dapat menginduksi respons imun & ketahanan udang terhadap infeksi V. harveyi.Kata kunci: Gracilaria verrucosa, rumput laut, Vibrio harveyi, vibriosis, udang vaname

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The Antibacterial Activity of Erythrocytes From Goose (Anser domesticus) Can Be Associated With Phagocytosis and Respiratory Burst Generation

Frontiers in Immunology ◽

10.3389/fimmu.2021.766970 ◽

2022 ◽

Vol 12 ◽

Author(s):

Youcheng Yang ◽

Jiajun Chen ◽

Linqing Lu ◽

Zizheng Xu ◽

Feng Li ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antibacterial Activity ◽

Respiratory Burst ◽

Bacterial Infections ◽

Pathogenic Bacteria ◽

Inflammatory Factors ◽

Total Blood ◽

Wide Range ◽

Avian Erythrocytes ◽

Adhesion Activity

In the lumen of blood vessels, there are large numbers of erythrocytes, which are approximately 95% of the total blood cells. Although the function of erythrocytes is to transport oxygen in the organism, recent studies have shown that mammalian and teleost erythrocytes are involved in the immune response against bacterial infections. However, the immune mechanisms used by avian erythrocytes are not yet clear. Here, we demonstrated that erythrocytes from goose have the ability to phagocytose as well as conduct antimicrobial activity. Firstly, we revealed the phagocytosis or adhesion activity of goose erythrocytes for latex beads 0.1-1.0 μm in diameter by fluorescence microscopy, and scanning and transmission electron microscopy. The low cytometry results also proved that goose erythrocytes had a wide range of phagocytic or adhesion activity for different bacteria. Followed, the low cytometry analysis data further explored that the goose erythrocytes contain the ability to produce reactive oxygen species (ROS) and inducible nitric oxide synthase (iNOS) in response to bacterial stimulation, and also up-regulated the expression of NOX family includes NOX1 and NOX5. Finally, we also found that goose erythrocytes showed a powerful antibacterial activity against all the three bacteria, meanwhile the stimulation of three kinds of bacteria up-regulated the expression of inflammatory factors, and increased the production of antioxidant enzymes to protect the cells from oxidative damage. Herein, our results demonstrate that goose Erythrocytes possess a certain phagocytic capacity and antioxidant system, and that the antimicrobial activity of erythrocytes can occurred through the production of unique respiratory burst against foreign pathogenic bacteria, which provides new clues to the interaction between bacteria and avian erythrocytes.

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