Intranasal immunisation with recombinant Lactococcus lactis displaying either anchored or secreted forms of Proteus mirabilis MrpA fimbrial protein confers specific immune response and induces a significant reduction of kidney bacterial colonisation in mice

Nasal immunization with attenuated Salmonella Typhimurium expressing an MrpA–TetC fusion protein significantly reduces Proteus mirabilis colonization in the mouse urinary tract

“…As in previous works, no significant individual correlation was found between reduction in bacterial counts and antibody levels (Scavone et al, 2007;Pellegrino et al, 2003). The protective role of serum antibodies against mucosal pathogens is still debatable.…”

“…recovered from bladders of vaccinated mice compared to the PBS-treated mice. This had not been achieved when another live vaccination approach based on MrpA expression by Lactococcus lactis was used (Scavone et al, 2007). In all other immunized groups of animals, the numbers of P. mirabilis c.f.u.…”

“…Different degrees of protection have been achieved using different fimbrial proteins, such as MrpA or the fimbrial adhesin MrpH (Li et al, 2004), and also diverse delivery systems have been analysed (Pellegrino et al, 2003;Scavone et al, 2007).…”

“…Three hundred microlitres 26 sample buffer was added and the tubes were boiled for 5 min for SDS-PAGE and subsequent Western blot analysis. For Western blotting, an MrpA rabbit polyclonal antiserum previously generated in our laboratory (Scavone et al, 2007) and a rabbit polyclonal anti-TetC antiserum (kindly provided by C. M. Khan, Newcastle University) were used.…”

Oral administration of recombinantNeisseria meningitidisPorA genetically fused toH. pyloriHpaA antigen increases antibody levels in mouse serum, suggesting that PorA behaves as a putative adjuvant

“…The protocol was adapted from Gu et al 71 and Scavone et al 72 Five groups of 7 female BALB/c mice each, aged 7-9 weeks, were separated as follows: Control group 1, PBS group orally immunized with 6 doses of 200 ml of buffer (PBS:7.5% NaHCO3 in 4:1 ratio); Control group 2, pSEC group immunized with L. lactis carrying only the pSEC cloning vector lacking the nisin promoter, with 3 primary daily doses (approximately 1-5 £ 10 9 CFU/mice) given in the first week and 3 similar booster doses one days 15, 16 and 17; HpaA control group 3 immunized with L. lactis expressing the H. pylori HpaA antigen cloned in pSEC and induced with 10 ng/ml nisin; PorA 351 -HpaA hybrid group 4 immunized with L. lactis expressing the larger hybrid cloned in pSEC; and PorA 222 -Hpa hybrid group 5 expressing the smaller hybrid. All oral immunizations, except group 1, were performed using the L. lactis grown under the same conditions, induced with nisin, suspended in a solution of PBS:7.5% NaHCO 3 (4:1), administered in a volume of 200 ml using an orogastric Tygon tubing.…”