Responses of monosex nile tilapia (Oreochromis niloticus) to intraperitoneal challenge by Streptococcus iniae after vaccination with ghosts of the bacterium

Abstract

The vaccine potential of Streptococcus iniae ghosts produced by gene E mediated lysis was investigated using tilapia (Oreochromis niloticus). Tilapia immunized with S. iniae ghosts (SIG) and formalin killed S. iniae (FKC) vaccines showed significantly higher serum agglutination titres than control fish. Fish immunized with SIG showed no significant differences with fish immunized with FKC in serum agglutination titres, but showed significantly higher bactericidal activity than fish immunized with FKC. Furthermore, fish immunized with SIG showed higher protection than fish immunized with FKC. As this promising type of a non-living whole cell envelope preparation seems to be favorable over conventional vaccines, we suggest S. iniae ghosts as a new vaccine candidate. (Bangl. vet.

Generation of a Novel Staphylococcus aureus Ghost Vaccine and Examination of Its Immunogenicity against Virulent Challenge in Rats

“…These data indicated that immunization with SAGs orally, subcutaneously, or intravenously efficiently produced bacterium-killing antibodies after a challenge. Recently, it has also been reported that S. iniae ghost vaccine stimulated higher serum bactericidal antibody levels than formalin-killed vaccine and protected experimental animals from a subsequent challenge with S. iniae (13). An earlier report showed that peptidoglycan induces strong bactericidal antibodies capable of eradicating the bacterial pathogen (21).…”

“…Serum bactericidal activity (SBA) was determined as described previously (13,18), with some modifications. In brief, 100 l of a bacterial suspension (1 ϫ 10 6 CFU/ml) was added to 25 l of serum and incubated at room temperature for 1 h. After incubation, the mixture was spread onto selective medium and incubated at 37°C for 48 h. For the control, serum was replaced with PBS.…”

“…Interestingly, Ra et al (12) have demonstrated that Escherichia coli/Streptococcus iniae glyceraldehyde 3-phosphate dehydrogenase ghosts, produced with a double-cassette vector system, protected aquatic fish from streptococcal diseases. Exceptionally, S. iniae ghosts produced by E gene-mediated lysis were being suggested as a potential vaccine candidate (13). However, a number of studies have demonstrated that the lysis efficiency of genetically inactivated BGs was 99.9% (10,14), suggesting a potential risk of their use as a vaccine.…”

Dietary supplementation of garlic ( Allium sativum ) modulates gut microbiota and health status of tilapia ( Oreochromis niloticus ) against Streptococcus iniae infection

“…An overnight culture of S. iniae in nutrient broth (NB) was harvested to approximately 10 6 CFU/ml and suspended in phosphate-buffer saline (PBS) (Rahman et al, 2017). Fish were anaesthetized to some extent by 60 mg/L solution of MS-222 (Sigma-Aldrich, USA) and 100 μl (10 6 CFU/ml) of bacterial suspension was intramuscularly injected at the dorsal side of each fish (Garcia, Müller, Freitas & Silva, 2010;Hossain et al, 2012).…”

“…The incidence of drug-resistant Streptococcus spp. in culture fish and pond has frequently been reported in Bangladesh (Hossain, Ehsan, Rahman, Chowdhury & Haq, 2012). Consequently, screening of medicinal plant parts for herbal recovery has long been studied as an alternative of commercial drugs (Awad & Awaad, 2017;Ramudu & Dash, 2013).…”