Immune response and protective efficacy of two new adjuvants, Montanide™ ISA 763B VG and Montanide™ GEL02, administered with a Streptococcus agalactiae ghost vaccine in Nile tilapia (Oreochromis niloticus).

Streptococcus agalactiae is one of the most important pathogens infecting tilapia worldwide and causes meningoencephalitis, septicemia and high mortalities with considerable losses. Various types of vaccines have been developed against S. agalactiae infection, such as inactivated vaccines, live attenuated vaccines and subunit vaccines. Bacterial ghosts (BGs) are nonliving, empty cell envelopes and have been reported as novel vaccine candidates. Therefore, the main aims of this study were to develop an S. agalactiae ghost vaccine (SAGV) and to evaluate the immune response and protective effect of SAGV against S. agalactiae with two novel adjuvants, Montanide™ ISA 763B VG and Montanide™ GEL02. Nile tilapia, mean weight 50 g, were divided into four groups as follows; 1) fish injected with PBS as control, 2) fish injected with the SAGV alone; 3) fish injected with the SAGV+Montanide™ ISA 763B VG; and 4) fish injected with SAGV+Montanide™ GEL02. Following vaccination, innate immunity parameters including serum lysozyme, myeloperoxidase, catalase, and bactericidal activity were all significantly enhanced. Moreover, specific serum IgM antibodies were induced and reached their highest level 2-8 weeks post vaccination. Importantly, the relative percent survival of tilapia vaccinated against the SAGV formulated with both adjuvants was 80-93%. Furthermore, the transcription of immune-related genes (IgM, TCRß, IL-1ß, IL-8 and TNFα) were up-regulated in tilapia after vaccination, indicating that both cellular and humoral immune responses were induced by these adjuvanted vaccines. In summary, Montanide™ ISA 763B VG and Montanide™ GEL02 can enhance immunoprotection induced by the SAGV vaccine against streptococcosis, demonstrating that both have value as potential adjuvants of fish vaccines.

Preclinical safety and immunogenicity of Streptococcus pyogenes (Strep A) peptide vaccines.

We have developed two candidate vaccines to protect against multiple strains of Strep A infections. The candidates are combinatorial synthetic peptide vaccines composed of a M protein epitope (J8 or p*17) and a non-M protein epitope (K4S2). To enhance immunogenicity, each peptide is conjugated to the carrier protein CRM197 (CRM) and formulated with aluminium hydroxide adjuvant Alhydrogel (Alum) to make the final vaccines, J8-CRM + K4S2-CRM/Alum and p*17-CRM + K4S2-CRM/Alum. The safety and toxicity of each vaccine was assessed. Sprague Dawley rats were administered three intramuscular doses, over a six-week study with a 4-week recovery period. A control group received CRM only formulated with Alum (CRM/Alum). There was no evidence of systemic toxicity in the rats administered either vaccine. There was an associated increase in white blood cell, lymphocyte and monocyte counts, increased adrenal gland weights, adrenocortical hypertrophy, and increased severity of granulomatous inflammation at the sites of injection and the associated inguinal lymph nodes. These changes were considered non-adverse. All rats administered vaccine developed a robust and sustained immunological response. The absence of clinical toxicity and the development of an immunological response in the rats suggests that the vaccines are safe for use in a phase 1 clinical trial in healthy humans.

Preclinical safety study of a recombinant Streptococcus pyogenes vaccine formulated with aluminum adjuvant.

A recombinant vaccine composed of a fusion protein formulated with aluminum hydroxide adjuvant is under development for protection against diseases caused by Streptococcus pyogenes. The safety and local reactogenicity of the vaccine was assessed by a comprehensive series of clinical, pathologic and immunologic tests in preclinical experiments. Outbred mice received three intramuscular injections of 1/5th of the human dose (0.1 ml) and rabbits received two injections of the full human dose. Control groups received adjuvant or protein antigen. The vaccine did not cause clinical evidence of systemic toxicity in mice or rabbits. There was a transient increase of peripheral blood neutrophils after the third vaccination of mice. In addition, the concentration of acute phase proteins serum amyloid A and haptoglobin was significantly increased 1 day after injection of the vaccine in mice. There was mild transient swelling and erythema of the injection site in both mice and rabbits. Treatment-related pathology was limited to inflammation at the injection site and accumulation of adjuvant-containing macrophages in the draining lymph nodes. In conclusion, the absence of clinical toxicity in two animal species suggest that the vaccine is safe for use in a phase I human clinical trial. Copyright © 2016 John Wiley & Sons, Ltd.

Preclinical immunogenicity and safety of a Group A streptococcal M protein-based vaccine candidate.

Streptococcus pyogenes (group A streptococcus, GAS) causes a wide range of clinical manifestations ranging from mild self-limiting pyoderma to invasive diseases such as sepsis. Also of concern are the post-infectious immune-mediated diseases including rheumatic heart disease. The development of a vaccine against GAS would have a large health impact on populations at risk of these diseases. However, there is a lack of suitable models for the safety evaluation of vaccines with respect to post-infectious complications. We have utilized the Lewis Rat model for cardiac valvulitis to evaluate the safety of the J8-DT vaccine formulation in parallel with a rabbit toxicology study. These studies demonstrated that the vaccine did not induce abnormal pathology. We also show that in mice the vaccine is highly immunogenic but that 3 doses are required to induce protection from a GAS skin challenge even though 2 doses are sufficient to induce a high antibody titer.

Streptococcus pneumoniae: distribución de serotipos, sensibilidad antibiótica, factores de riesgo y mortalidad en Galicia en un periodo de 2 años / Streptococcus pneumoniae: Serotype distribution, antimicrobial susceptibility, risk factors and mortality in Galicia over a two year-period

INTRODUCCIÓN: Para conocer la epidemiología de la infección neumocócica en Galicia (España) tras la incorporación de la vacuna conjugada antineumocócica, se determinaron durante los años 2011 y 2012 la distribución de serotipos, sensibilidad antibiótica, factores de riesgo y mortalidad asociada de los casos de enfermedad neumocócica invasiva (ENI). MÉTODOS: Se estudiaron todas las cepas causantes de ENI en Galicia. El serotipado se realizó por aglutinación y reacción de Quellung. Se determinó la sensibilidad a penicilina, cefotaxima, eritromicina, vancomicina y levofloxacino. Se consideraron factores de riesgo la patología respiratoria crónica, la patología cardíaca, la patología hepática, la patología renal, la diabetes mellitus y la inmunodeficiencia no VIH y VIH. RESULTADOS: Se recogieron 555 cepas. Se encontraron 43 serotipos diferentes, los más frecuentes: serotipo 3 (17,5%), serotipo 7F (12,6%), serotipo 19A (9,4%), serotipo 14 (4,1%), serotipo 6C (4,1%), serotipo 11A (4%) y serotipo 22F (3,8%). El 57,1% de los serotipos aislados estaban incluidos en VNC-13V. Se encontraron 2 cepas no sensibles a penicilina y otras 2 a cefotaxima. El 24,7% de las cepas fueron no sensibles a eritromicina (26,9% en 2011 y 22,5% en 2012). La tasa de letalidad fue del 16,5%, llegando al 23,3% en mayores de 75 años. Las patologías con riesgo de morir que mostraron significación estadística fueron: hepática, renal e inmunodeficiencia no VIH. CONCLUSIONES: El serotipo 3 fue el mayoritario en Galicia. Se encontraron muy pocas cepas no susceptibles a penicilina y un descenso de resistencia a eritromicina de 2011 a 2012. Se observó un incremento de letalidad en relación con la edad del paciente. Padecer patología hepática, renal o inmunodeficiencia no VIH aumentó el riesgo de muerte

INTRODUCTION: To examine the epidemiology of pneumococcal infection in Galicia (Spain) after the incorporation of the pneumococcal conjugate vaccine, and to determine serotype distribution, antibiotic susceptibility, risk factors and associated mortality in cases of invasive pneumococcal disease (IPD) during 2011 and 2012. METHODS: All strains causing IPD in Galicia were studied. Serotyping was performed by agglutination and Quellung reaction. Antibiotic sensitivity to penicillin, cefotaxime, erythromycin, vancomycin, and levofloxacin was determined. The risk factors considered were chronic respiratory disease, heart disease, liver disease, kidney disease, diabetes mellitus, and HIV and non-HIV immunodeficiency. RESULTS: A total of 555 strains were collected, with 43 different serotypes being found. The most frequently isolated ones were: serotype 3 (17.5%), serotype 7F (12.6%), serotype 19A (9.4%), serotype 14 (4.1%), serotype 6C (4.1%), serotype 11A (4%) and serotype 22F (3.8%). 57.1% of isolates were serotypes included in VNC-13V. Two non-penicillin-sensitive strains and two others were not sensitive to cefotaxime, and 24.7% of the strains were not susceptible to erythromycin (26.9% in 2011 and 22.5% in 2012). The case fatality rate was 16.5%, reaching 23.3% in patients over 75 years. Diseases with a statistically significant risk of mortality were: liver, kidney and immunodeficiency without HIV. CONCLUSIONS: Serotype 3 was the most frequent in Galicia. Very few strains were not susceptible to penicillin. Erythromycin resistance decreased from 2011 to 2012. It is highlighted that mortality increases with age. Liver disease, renal disease and non-HIV immunodeficiency increases the mortality risk

Homologous whole bacterin vaccination is not able to reduce Streptococcus suis serotype 9 strain 7997 transmission among pigs or colonization.

Streptococcus suis (S. suis) is an important porcine pathogen worldwide, and antibiotics are often applied to treat or prevent clinical signs. Vaccination could be an alternative measure to reduce the abundant use of antimicrobials. The aim of this study was to determine the effect of vaccination with homologues whole bacterin vaccine containing S. suis serotype 9 strain 7997 on transmission of this serotype among pigs and on mucosal colonization. Caesarean derived, colostrum deprived pigs (N=50) were housed pair wise. Thirteen pairs were vaccinated intramuscularly with 2-3×10(9) colony forming units (CFU) inactivated S. suis serotype 9 per dose and α-tocopherolactetaat as adjuvant at 3 and 5 weeks of age; twelve pairs served as non-vaccinated controls. At 7 weeks of age, one pig of each pair was intranasally inoculated with 1-2×10(9)CFU of the homologues strain, whereas the other pig of each pair was contact-exposed. Tonsil brushings and saliva swabs were collected for 4 weeks, and tested for the presence of S. suis by bacteriological culture. No differences in number of S. suis in the tonsils or saliva samples or in clinical signs were observed between vaccinated and control pigs. In all pairs, transmission between inoculated and contact exposed pigs occurred, and no difference was observed in rate at which this occurred. The estimated transmission rate parameter ß between vaccinated pigs was ß(v)=5.27/day, and for non-vaccinated pigs ß(nv)=2.77/day (P=0.18). It was concluded that vaccination against S. suis serotype 9 did not reduce transmission, nor colonization and that there were no indications that protection against clinical signs was induced.

Enhancement of anti-allergic effects mediated by the Kampo medicine Shoseiryuto (Xiao-Qing-Long-Tang in Chinese) with lysed Enterococcus faecalis FK-23 in mice.

Kampo is a traditional Japanese medicine originating from ancient Chinese medicine which included the administration of herbal prescription, lifestyle advice and acupuncture. Orally administered Kampo prescriptions are believed to be influenced by diet and intestinal microbiota. However, reports on the Kampo administration effects are still limited. Shoseiryuto (TJ-19), which has anti-allergic and anti-inflammatory properties, is a Kampo prescription used clinically for the treatment of allergic bronchial asthma. We examined whether Shoseiryuto administration is affected by a probiotic product, lysed Enterococcus faecalis FK-23 (LFK). BALB/c mice were sensitized with cedar pollen allergen, and the peritoneal accumulation of eosinophils was induced. During a sensitization period of 21 days, varying amounts of Shoseiryuto (and saline as a control) were administered to the mice. The accumulation of eosinophils was significantly reduced by 30 mg/day doses of Shoseiryuto but not by 3 or 9 mg/day doses. Similarly, 3 mg/day Shoseiryuto, 30 mg/day LFK, 3 mg/day of Shoseiryuto co-administered with 30 mg/day of LFK, and saline control were compared. A significant reduction in the accumulation of eosinophils was observed at 3 mg/day Shoseiryuto co-administered with 30 mg/day of LFK. These results suggest that Shoseiryuto-mediated anti-allergic effects are enhanced by the probiotic (LFK). Although not significant statistically, serum allergen-specific and total IgE levels in the treatment group exposed to the mixed agent (ie. Shoseiryuto and LFK) were generally lower than those receiving either one alone. The results indicate a synergistic effect of a Kampo medicine (Shoseiryuto, Xiao-Qing-Long-Tang in Chinese) and lysed Enterococcus faecalis FK-23 on allergic responses in mice.

A vaccine against S. pyogenes: design and experimental immune response.

Streptococcus pyogenes causes severe invasive infections: the post-streptococcal sequelae of acute rheumatic fever (RF) and rheumatic heart disease (RHD), acute glomerulonephritis, and uncomplicated pharyngitis and pyoderma. Efforts to produce a vaccine against S. pyogenes began several decades ago, and different models have been proposed. Here, we describe the methodology used in the development of a new vaccine model, consisting of both T and B protective epitopes constructed as synthetic peptides and recombinant proteins. Two adjuvants were tested in an experimental inbred mouse model: a classical Freund's adjuvant and a new adjuvant (AFCo1) that induces mucosal immune responses and is obtained by calcium precipitation of a proteoliposome derived from the outer membrane of Neisseria meningitides B. The StreptInCor vaccine epitope co-administrated with AFCo1 adjuvant induced mucosal (IgA) and systemic (IgG) antibodies as preferential Th1-mediated immune responses. No autoimmune reactions were observed, suggesting that the vaccine epitope is safe.

StreptAvax (ID Biomedical).

ID Biomedical, under license from the University of Tennessee, is developing StreptAvax, a potential subunit vaccine against group A streptococcal infection. By January 2005, analysis of data from phase II clinical trials conducted in adults was completed. Pediatric trials are not expected to begin before 2007.

Effects of various adjuvants on efficacy of a vaccine against Streptococcus bovis and Lactobacillus spp in cattle.

OBJECTIVE: To determine efficacy of vaccines incorporating QuilA, alum, dextran combined with mineral oil, or Freund adjuvant for immunization of feedlot cattle against Streptococcus bovis and Lactobacillus spp. ANIMALS: 24 steers housed under feedlot conditions. PROCEDURE: Steers were randomly assigned to 4 experimental groups and a control group. Animals in experimental groups were inoculated on days 0 and 26 with vaccines containing Freund adjuvant (FCA), QuilA, dextran combined with mineral oil (Dex), or alum as adjuvant. Serum anti-S bovis and anti-Lactobacillus IgG concentrations were measured, along with fecal pH, ruminal fluid pH, and number of S bovis and Lactobacillus spp in ruminal fluid. RESULTS: Throughout the study, serum anti-S bovis and anti-Lactobacillus IgG concentrations for animals in the Dex, QuilA, and alum groups were similar to or significantly higher than concentrations for animals in the FCA group. Serum anti-S bovis and anti-Lactobacillus IgG concentrations were significantly increased on days 26 through 75 in all 4 experimental groups, and there was a linear relationship between anti-S bovis and anti-Lactobacillus IgG concentrations. For animals in the QuilA and Dex groups, mean pH of feces throughout the period of experiment were significantly higher and numbers of S bovis and Lactobacillus spp in ruminal fluid on day 47 were significantly lower than values for control cattle. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that immunization of feedlot steers against S bovis and Lactobacillus spp with vaccines incorporating Freund adjuvant, QuilA, dextran, or alum as an adjuvant effectively induced high, long-lasting serum anti-S bovis and anti-Lactobacillus IgG concentrations. Of the adjuvants tested, dextran may be the most effective.