Intranasal vaccination with adjuvant-free S. aureus antigens effectively protects mice against experimental sepsis.

Staphylococcus aureus (S. aureus) is a Gram-positive coccal bacterium comprising part of the human skin, nares and gastrointestinal tract normal microbiota. It is also an important cause of nosocomial/community-acquired infections in humans and animals, which can cause a diverse array of infections, including sepsis, which is a progressive systemic inflammation response syndrome that is frequently fatal. The emergence of drug-resistant strains and the high toxicity of the treatments used for these infections point out the need to develop an effective, inexpensive and safe vaccine that can be used prophylactically. In this work, we used an experimental sepsis model to evaluate the effectiveness of whole antigens from S. aureus (SaAg) given by the intranasal route to induce protective immunity against S. aureus infection in mice. BALB/c mice were vaccinated via intranasal or intramuscular route with two doses of SaAg, followed by biocompatibility and immunogenicity evaluations. Vaccinated animals did not show any adverse effects associated with the vaccine, as determined by transaminase and creatinine measurements. Intranasal, but not intramuscular vaccination with SaAg led to a significant reduction in IL-10 production and was associated with increased level of IFN-γ and NO. SaAg intranasal vaccination was able to prime cellular and humoral immune responses and inducing a higher proliferation index and increased production of specific IgG1/IgG2, which contributed to decrease the bacterial load in both liver and the spleen and improve survival during sepsis. These findings present the first evidence of the effectiveness of whole Ag intranasal-based vaccine administration, which expands the vaccination possibilities against S. aureus infection.

Effect of total splenectomy in the lipid profile in mice.

PURPOSE: To analyze total splenectomy effect on the lipid profile - total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), very-low-density lipoprotein cholesterol (VLDL) and triglycerides levels, in Balb/c mice. METHODS: Thirty Balb/c male mice, one (1) month old and average weight 26.2g ± 4.0 were used in the experiment. They were distributed into three groups of 10 animals each: a control group (non-operated), a simulation group (spleen manipulation) and the splenectomy group. The animals were subjected to blood sampling to measure plasma lipid levels, at three different times: before surgery, days 30 and 75 of the experiment. RESULTS: Increased total cholesterol and LDL were observed in the control group from the start to end of the experiment. The simulation group showed increased rates of VLDL and triglycerides at the 30th and 75th days. Splenectomized animals showed no significant change. CONCLUSION: Total splenectomy did not induce increased plasma lipids levels of in Balb/c mice.

Effect of total splenectomy in the lipid profile in mice

PURPOSE: To analyze total splenectomy effect on the lipid profile - total cholesterol, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), very-low-density lipoprotein cholesterol (VLDL) and triglycerides levels, in Balb/c mice. METHODS: Thirty Balb/c male mice, one (1) month old and average weight 26.2g ± 4.0 were used in the experiment. They were distributed into three groups of 10 animals each: a control group (non-operated), a simulation group (spleen manipulation) and the splenectomy group. The animals were subjected to blood sampling to measure plasma lipid levels, at three different times: before surgery, days 30 and 75 of the experiment. RESULTS: Increased total cholesterol and LDL were observed in the control group from the start to end of the experiment. The simulation group showed increased rates of VLDL and triglycerides at the 30th and 75th days. Splenectomized animals showed no significant change. CONCLUSION: Total splenectomy did not induce increased plasma lipids levels of in Balb/c mice. .

Micronucleus test in peripheral blood of rats treated with hyperbaric oxygen after subtotal splenectomy preserving the lower pole.

PURPOSE: To assess the mutagenic potential of the oxygen inhalation therapy (HBO), by means of the micronucleus test, performed in peripheral blood of rats that underwent subtotal splenectomy with lower pole preservation (ESTPI), after HBO sessions or simulations. METHODS: Eighteen male Wistar rats, were distributed into three groups of six animals: group 1 - submitted to ESTPI and HBO sessions; group 2 - submitted to ESTPI and HBO simulations; group 3 - underwent cyclophosphamide administration. In groups 1 and 2, blood samples from the animals' tails were collected before surgery (T0) and immediately after the 13th HBO session or simulation (T1). In group 3, tail blood samples were collected from animals before (T0) and 24 hours after (T1) cyclophosphamide (CP) delivery. The number of micronucleated normochromatic erythrocytes (MNNCE) was determined by blind counting 2000 normochromatic erythrocytes (NCE) per animal. RESULTS: Micronuclei average after CP delivery in group 3 was higher than before its use, thus confirming the mutagenic activity of this drug (p=0.01). In groups 1 and 2, no significant difference in the average of Micronuclei was observed when comparing it to blood samples before and after the 13th HBO session or simulation. CONCLUSION: The treatment protocol used in this study did not induce Micronucleus formation in animals submitted to ESTPI and HBO treatment or simulation.

Micronucleus test in peripheral blood of rats treated with hyperbaric oxygen after subtotal splenectomy preserving the lower pole

PURPOSE: To assess the mutagenic potential of the oxygen inhalation therapy (HBO), by means of the micronucleus test, performed in peripheral blood of rats that underwent subtotal splenectomy with lower pole preservation (ESTPI), after HBO sessions or simulations. METHODS: Eighteen male Wistar rats, were distributed into three groups of six animals: group 1 - submitted to ESTPI and HBO sessions; group 2 - submitted to ESTPI and HBO simulations; group 3 - underwent cyclophosphamide administration. In groups 1 and 2, blood samples from the animals' tails were collected before surgery (T0) and immediately after the 13th HBO session or simulation (T1). In group 3, tail blood samples were collected from animals before (T0) and 24 hours after (T1) cyclophosphamide (CP) delivery. The number of micronucleated normochromatic erythrocytes (MNNCE) was determined by blind counting 2000 normochromatic erythrocytes (NCE) per animal. RESULTS: Micronuclei average after CP delivery in group 3 was higher than before its use, thus confirming the mutagenic activity of this drug (p=0.01). In groups 1 and 2, no significant difference in the average of Micronuclei was observed when comparing it to blood samples before and after the 13th HBO session or simulation. CONCLUSION: The treatment protocol used in this study did not induce Micronucleus formation in animals submitted to ESTPI and HBO treatment or simulation. .