Encapsulated Bacteria Research Articles

Survival and stability of free and encapsulated probiotic bacteria under simulated gastrointestinal conditions and in pasteurized grape juice

The present study was designed to explicate the effect of encapsulation on the stability of Bifidobacterium bifidum in pasteurized grape juice and in vitro gastrointestinal conditions. Purposely, hydrogel beads were prepared using sodium alginate and K-carrageenan by internal gelation method. Free and encapsulated probiotics were incorporated in pasteurized grape juice samples. The initial count in grape juice samples with free probiotic cells was calculated as 9.35 log cfu/mL that reduced to 6.58 log cfu/mL after 35 days. Likewise, the probiotic count, that is, in samples containing encapsulated probiotics reduced to a level of 8.51 log cfu/mL and 7.09 log cfu/mL after the mentioned storage period. The number of free viable cells in juice samples was lower than (107 cfu/g) the minimum recommend level. Similarly, the free cells showed a poor survival under simulated gastrointestinal conditions. Furthermore, encapsulation affected the physicochemical (pH, acidity, and Brix) and sensorial characteristics of the juice samples. Practical applications The probiotic delivery through carrier food and under hostile gastrointestinal conditions is a great challenge due to their low survival. The encapsulation technology can be used to protect the target delivery of probiotics. The encapsulation technology is a useful tool for delivering the probiotics for both dairy and nondairy food matrices. Encapsulation also ensures the recommended therapeutic level (1107–108 cfu) during transit and storage.

Functional exploration of free and encapsulated probiotic bacteria in yogurt and simulated gastrointestinal conditions.

The core objective of the current study was to evaluate the effect of microencapsulation on the viability and stability of probiotic bacteria in yogurt and simulated gastrointestinal conditions. For this purpose, probiotic bacteria were encapsulated with sodium alginate and carrageenan by encapsulator. Yogurt was prepared with the incorporation of free and encapsulated probiotic bacteria and was analyzed for physicochemical, microbiological, and sensorial attributes. Encapsulation and storage exhibited a significant (p < .05) effect on different parameters of yogurt. An increasing trend in syneresis and acidity while a decreasing trend in viscosity, pH, viability, and stability were observed. The value of syneresis increased from 2.27 ± 0.17 to 2.9 ± 0.14 and acidity from 0.48 ± 0.04 to 0.64 ± 0.01 during 4 weeks of storage. The value of viscosity decreased from 3.68 ± 0.21 to 2.42 ± 0.09 and pH from 4.88 ± 0.31to 4.43 ± 0.36 during 28 days of storage. Unencapsulated (free) cells exhibited poor survival. The viable cell count of probiotic bacteria in the free‐state in yogurt was 9.97 logs CFU/ml at zero‐day that decreased to 6.12 log CFU/ml after 28 days. However, encapsulation improved the viability of the probiotics in the prepared yogurt and GIT. The cell count of probiotics encapsulated with sodium alginate and carrageenan was 9.91 logs CFU/ml and 9.89 logs CFU/ml, respectively, at zero‐day that decreased to 8.74 logs CFU/ml and 8.39 log CFU/ml, respectively. Free cells (unencapsulated) showed very poor survival. Similarly, during in vitro gastrointestinal assay, the survival rate of encapsulated probiotic bacteria in simulated gastric solution and intestinal solutions was higher than that of free cells. In the case of encapsulated bacteria, only 3 logs while for free cells, 7 log reduction was recorded. Sodium alginate microcapsules exhibited better release profile than carrageenan. Conclusively, microencapsulation improved the survival of probiotic bacteria in carrier food as well as in simulated gastrointestinal condition.

The immunity features and defects against primary cytomegalovirus infection post-splenectomy indicate an immunocompromised status: A PRISMA-compliant meta-analysis.

Background:To evaluate if splenectomy results in severely impaired immune responses against primary cytomegalovirus (CMV) infection compared to the general immunocompetent population.Methods:We performed a systemic literature review to study CMV infections in splenectomized individuals, a special population group presently considered immunocompetent to viral infections. We retrieved 30 cases with established CMV infection post-splenectomy and we recorded their disease manifestations, laboratory findings, immunological studies, and histopathology reports. In addition, we retrieved numerous multidisciplinary articles in view of post-splenectomy immunology defects, as well as of immune responses to primary invading CMV in the absence of the spleen. Two clinical studies directly comparing splenectomized with nonsplenectomized individuals under severe iatrogenic immunosuppression as well as the numerically largest review articles of CMV infections in immunocompetent were retained.Results:Splenectomy results in the loss of spleen's ability to fend-off blood-borne pathogens and impairs the link between innate and adaptive immunity. The major post-splenectomy immune-defects against CMV are: weakened, delayed or absent anti-CMV IgM, and compensatory marked IgG response; severely impaired B-cell and CD4+, CD8+ T-cells function responses; and post-splenectomy, bone marrow compensates for the absence of spleen's immune responses against CMV, mimicking a monoclonal T-cell lymphoproliferative process.Conclusion:The puzzled diagnosis of the CMV syndrome post-splenectomy is of the most challenging and misleading, resulting in risky and costly interventions and a subsequent prolonged hospitalization (2 months). The mounting multi-disciplinary literature evidence renders us to suggest that splenectomized individuals are not only prone to encapsulated bacteria but also behave as immunocompromised to CMV.

Serologic response to meningococcal vaccination in patients with cold agglutinin disease (CAD) in the novel era of complement inhibition

Cold agglutinin disease (CAD) is a rare, potentially life-threatening acquired autoimmune hemolytic anemia characterized by hemagglutination and hemolysis due to immunoglobulin-mediated (usually IgMκ) classic complement pathway activation. Complement inhibition (CI) represents a novel treatment option to control hemolysis. Due to CI patients (pts) are susceptible to encapsulated bacteria e.g. N. meningitidis. Therefore, meningococcal vaccination on CI is mandatory. In this study serologic response to the tetravalent conjugate vaccine Menveo® was analyzed in CAD pts on eculizumab treatment (DECADE trial) using rabbit serum as complement source (rSBA). Protective rSBA titers varied for meningococcal serogroups and over time reflecting an early decline to even non-protective rSBA titers. These data highlight the importance of serologic analyses under chronic CI. Currently, re-vaccination with a tetravalent meningococcal conjugate vaccine every 3 years is recommended on chronic CI. However, re-vaccination on CI might further rely on serologic analyses, implying even early booster vaccinations similar to adults with (functional) asplenia.

Pengaruh Pemberian Probiotik Terenkapsulasi Pada Pakan Ayam Petelur Terhadap Kolesterol telur Ayam

This study aims to determine the effect of probiotic administration encapsulated on the cholesterol content of egg laying eggs. Probiotics are given to laying hens (phase layer), once a day for 4 weeks orally. In this study a completely randomized design (CRD) was used with three treatments, namely, probiotic encapsulated lactic acid bacteria (BAL) (E1), commercial probiotics (E2), and without probiotics (E0) with 4 replications. The variables observed in this study were encapsulated probiotic viability, egg weight (g), egg index (%), and total egg cholesterol content (mg / g). The results showed that the viability of probiotic bacteria decreased by 3.34 cfu / g after 4 weeks of storage at 4OC. Average egg weight at E0; E1; and E2 are 62.63 g, 62.67 g, and 64.15 g. Average egg index at E0; E1; and E2 are 71.13%, 75.54%, and 77.2%. The average cholesterol content at E0; E1; and E2 is 3.75 mg / g, 3.25 mg / g and 3.25 mg / g. The administration of encapsulated probiotics did not affect the quality of egg weight but it affected the egg index and total cholesterol content of egg laying eggs.

IN VITRO EVALUATION OF ENCAPSULATED PROBIOTIC BACTERIA SUPPLEMENTATION TO RUMINANT RATIONS

The aim of this study was to in vitro evaluate encapsulated probiotic supplementation to ruminant rationson degradation and fermentation parameters. The ration consisted of 40% alfalfa hay and 60% concentrate feed mixture. Encapsulated and not encapsulated probiotic were supplemented with level of 106cfu/kg of the total dry matter of ration (DM) and compared with encapsulation media (Sodium Alginate, SA) and control (not supplemented ration). DM and OM degradation and total gas production as well as fermentation parameters of the incubated samples were determined after 24 h of fermentation. Significant (P<0.01) increases in in-vitro DM degradability was observed for the experimental ration supplemented with encapsulated or not encapsulated probiotics at levels (106 CFU/ kg DM) and SA treatment compared to control ration. Also, significant (P<0.05) improvement in OM degradability was recorded for the ration supplemented with not encapsulated probiotics bacteria compared to the other treatments. Moreover no significant differences were observed between the control ration and the rations supplemented with encapsulated probiotics or SA only, as well as no significant difference was recorded between the ration supplemented with encapsulated probiotics and the ration supplemented with SA only. Probiotics bacteria supple mentation in the form of not encapsulated probiotic resulted significant increases in in vitro total gas production per sample and per g DM, OM, dDM, NDF and ADF after 24 hours incubation period compared to the other experimental rations (control, encapsulated probiotic and SA). While significant increase in total gas production per g dOM was observed for not encapsulated probiotic compared to encapsulated probiotic only. It could be concluded that, using encapsulated probiotics bacteria had no significant effect on DM degradability and may be induce decrease in gas production and fermentation parameters.

Use of saliva to monitor meningococcal vaccine responses: proposing a threshold in saliva as surrogate of protection

BackgroundMucosal antibodies against capsular polysaccharides offer protection against acquisition and carriage of encapsulated bacteria like Neisseria meningitidis serogroup C. Measurements of salivary antibodies as replacement for blood testing has important (cost-effective) advantages, particular in studies that assess the impact of large-scale vaccination or in populations in which blood sampling is difficult. This study aimed to estimate a threshold for meningococcal IgG salivary antibody levels to discriminate between unprotected and protected vaccinated individuals.MethodsMenA-, MenC-, MenW- and MenY-polysaccharide (PS) specific IgG levels in serum and saliva from participants in a meningococcal vaccination study were measured using the fluorescent-bead-based multiplex immunoassay. Functional antibody titers in serum against the four serogroups were measured with serum bactericidal assay using rabbit complement (rSBA). A threshold for salivary IgG was determined by analysis of ROC curves using a serum rSBA titer ≥128 as correlate of protection. The area under the curve (AUC) was calculated to quantify the accuracy of the salivary test and was considered adequate when ≥0.80. The optimal cut-off was considered adequate when salivary IgG cut-off levels provided specificity of ≥90%. True positive rate (sensitivity), positive predictive value, and negative predictive value were calculated to explore the possible use of salivary antibody levels as a surrogate of protection.ResultsThe best ROC curve (AUC of 0.95) was obtained for MenC, with an estimated minimum threshold of MenC-PS specific salivary IgG ≥3.54 ng/mL as surrogate of protection. An adequate AUC (> 0.80) was also observed for MenW and MenY with an estimated minimal threshold of 2.00 and 1.82 ng/mL, respectively. When applying these thresholds, all (100%) samples collected 1 month and 1 year after the (booster) meningococcal vaccination, that were defined as protective in the saliva test for MenC, MenW and MenY, corresponded with concomitant serum rSBA titer ≥128 for the respective meningococcal serogroups.ConclusionThe saliva test offers an alternative screening tool to monitor protective vaccine responses up to one year after meningococcal vaccination against MenC, MenW and MenY. Future (large) longitudinal vaccination studies evaluating also clinical protection against IMD or carriage acquisition are required to validate the currently proposed threshold in saliva.

EF-Tu From Non-typeable Haemophilus influenzae Is an Immunogenic Surface-Exposed Protein Targeted by Bactericidal Antibodies.

Non-typeable Haemophilus influenzae (NTHi), a commensal organism in pre-school children, is an opportunistic pathogen causing respiratory tract infections including acute otitis media. Adults suffering from chronic obstructive pulmonary disease (COPD) are persistently colonized by NTHi. Previous research has suggested that, in some bacterial species, the intracellular elongation factor thermo-unstable (EF-Tu) can moonlight as a surface protein upon host encounter. The aim of this study was to determine whether EF-Tu localizes to the surface of H. influenzae, and if such surface-associated EF-Tu is a target for bactericidal antibodies. Using flow cytometry, transmission immunoelectron microscopy, and epitope mapping, we demonstrated that EF-Tu is exposed at the surface of NTHi, and identified immunodominant epitopes of this protein. Rabbits immunized with whole-cell NTHi produced significantly more immunoglobulin G (IgG) directed against EF-Tu than against the NTHi outer membrane proteins D and F as revealed by enzyme-linked immunosorbent assays. Chemical cleavage of NTHi EF-Tu by cyanogen bromide (CNBr) followed by immunoblotting showed that the immunodominant epitopes were located within the central and C-terminal regions of the protein. Peptide epitope mapping by dot blot analysis further revealed four different immunodominant peptide sequences; EF-Tu41−65, EF-Tu161−185, EF-Tu221−245, and EF-Tu281−305. These epitopes were confirmed to be surface-exposed and accessible by peptide-specific antibodies in flow cytometry. We also analyzed whether antibodies raised against NTHi EF-Tu cross-react with other respiratory tract pathogens. Anti-EF-Tu IgG significantly detected EF-Tu on unencapsulated bacteria, including the Gram-negative H. parainfluenzae, H. haemolyticus, Moraxella catarrhalis and various Gram-positive Streptococci of the oral microbiome. In contrast, considerably less EF-Tu was observed at the surface of encapsulated bacteria including H. influenzae serotype b (Hib) and Streptococcus pneumoniae (e.g., serotype 3 and 4). Removal of the capsule, as exemplified by Hib RM804, resulted in increased EF-Tu surface density. Finally, anti-NTHi EF-Tu IgG promoted complement-dependent bacterial killing of NTHi and other unencapsulated Gram-negative bacteria as well as opsonophagocytosis of Gram-positive bacteria. In conclusion, our data demonstrate that NTHi EF-Tu is surface-exposed and recognized by antibodies mediating host innate immunity against NTHi in addition to other unencapsulated respiratory tract bacteria.

No Demonstrable Benefit of Penicillin in a Vaccinated Population of Children with Sickle Cell Disorder

UK and many National guidelines advise on the use of prophylactic antibiotics, immunisation and patient education to minimise the risk of severe infections by encapsulated organisms in patients with Sickle Cell Disorder. The UK vaccination schedule for sickle cell anaemia patients includes Pneumococcal, Meningococcal and Haemophilus influenzae type B (Hib) immunisation. Prophylactic Penicillin V is recommended as additional protection against Streptococcus pneumoniae (S.pneumoniae).In light of the findings in the papers by Oligbu et al, 2017, and Martin et al 2018, we aimed to retrospectively compare compliance with prophylactic Penicillin V against infection rates by S.pneumoniae,Neisseria meningitidis (N.meningitidis) and Hib . We hypothesised that the incidence of infections with IPD and other encapsulated organisms would be greater in patients who were not adherent with Penicillin V. Patients were considered compliant with prophylactic Penicillin V if 75% or more of their urine samples gave positive results.The study population consisted of 52 Sickle Cell patients, ranging from age 3 to 20years.Three patients were excluded as no urine samples had been collected from them in the 5 year period. Of the remaining 49 patients only 9 patients (18%) were had good adherence with Penicillin V over a 5 year period.100% of patients received prevenar vaccination (PCV-7 or PCV 13).73% received additional pneumovax.We retrospectively reviewed microbiology culture reports over a five year period. All microbiology reports were reviewed from the period, with the virulent encapsulated organisms of S.pneumoniae,N.meningitidis and Hib recorded, alongside any other bacterial infections.No patients had microbiological evidence of infection by virulent encapsulated bacteria. Six patients had cultures positive for other organisms: two Staphylococcus aureus positive sputum cultures, one Salmonella positive stool culture, two urine cultures positive for Escherichia coli, and one skin wound swab positive for Streptococcus pyogenes.Of the 6 organisms identified, 3 occurred in patients compliant with Penicillin V, and 3 occurred in patients who were non-compliant. Patients compliant with Penicillin V formed a small cohort (n=9), resulting in an apparently high incidence of infection (33%). In the non-compliant cohort (n=40), 8% had shown infection. Analysis by Fisher's Exact Test confirmed no significant difference in the incidence of infection between the two groups (p= 0.06).In a sickle cell disorder population where 82% of the patients were not 100% compliant with prophylactic Penicillin V, no significant encapsulated bacteria (S.pneumoniae,N.meningitidis or Hib) were cultured in a 5 year period in our cohort. Non-compliance with prophylactic Penicillin V was not associated with an increased incidence of infections by encapsulated organisms.The UK study (Oligbu et al) on IPD was performed in the PCV13 era and states a 49x increased risk of developing IPD and a 5x increase in mortality in children with sickle cell compared to their peers. However, most IPD cases were due to non-vaccine serotypes. A similar study from the US (Martin et al) found deaths only in the PCV7 cohort, it does not state if the patients were vaccinated with pneumovax 23.In conclusion 82% of children did not adhere to penicillin. We have not demonstrated any benefit in adhering to prophylactic penicillin. Adherence is poor and alternative approaches of standby antibiotics should be considered. We suggest focusing on vaccination as a preventative strategy is of more benefit. Martin OO, Moquist KL, Hennessy,JM, Nelson SC. Invasive pneumococcal disease in children with sickle cell disease in the pneumococcal conjugate vaccine era. Pediatr Blood Cancer. 2018;65:e26713. https://doi.org/10.1002/pbc.26713Oligbu G, Collins S , Streetly A, Dick, M, Ladhany, S. Risk of invasive pneumococcal disease in children with sickle cell disease in England: National observational cohort study, 2010 - 2015. Arch Dis Child 2017;102(Suppl1):A4-A4 DisclosuresNo relevant conflicts of interest to declare.

Serologic Response to Meningococcal Vaccination in Patients with Cold Agglutinin Disease (CAD) in the New Era of Complement Inhibition

BACKGROUND: Cold agglutinin disease (CAD) is an ultra-rare and potentially life-threatening, acquired autoimmune hemolytic anemia. It is characterized by hemagglutination and hemolysis due to immunoglobulin-mediated (usually IgMᴋ) classic complement pathway activation aggravated by infections and exposure to cold environmental temperatures. As conventional approaches are largely ineffective or short term in controlling hemolysis, complement inhibition (CI) (eculizumab-C5, BIVV009-C1s, and APL-2-C3) represents a novel and promising treatment option in these patients (pts). However, due to inhibition of complement cascade, pts are susceptible to encapsulated bacteria, especially N. meningitidis. Therefore, meningococcal vaccination is mandatory on CI to reduce the risk of infection.PATIENTS/METHODS: In this systematic study serologic response to the quadrivalent meningococcal polysaccharide conjugate vaccine (Menveo®) in pts with CAD (n=9; 8 females; mean age, 73 yrs (range 64-80 yrs)) was analyzed prior to vaccination and initiation of CI (eculizumab, DECADE Trial (Röth et. al, Blood 2015; 126:274)) and after vaccination at two distinct time intervals (median, 42 days (range 18-60 days) and median, 193 days (range 156-200 days) by measuring serum bactericidal antibody titers with external rabbit complement (rSBA) against meningococcal serogroups A, C, W135 and Y. In one pt rSBA titers were not assessable at the first interval following vaccination. By definition, serologic protection is defined by a rSBA titer ≥1:8 or a fourfold rise pre- to postvaccination.RESULTS: Serologic response in terms of protective rSBA titers to Menveo® after vaccination varied in CAD pts for the meningococcal serogroups and the different time points: A 25% (2/8), C 25% (2/8), W135 50% (4/8), Y 62% (5/8) at first observation compared to: A 0% (0/9), C 22% (2/9), W135 33% (3/9), Y 44% (4/9) at second rSBA titer measurement, reflecting an early decline in protective rSBA titers to non-protective titers over time (Fig. 1). However, no meningococcal infections have been observed in the analyzed cohort under CI. In pts. with a fourfold rise in rSBA titers pre- to postvaccination the beneficial role of conjugated meningococcal vaccinations in contrast to unconjugated vaccines, resembled by increased immunity with booster vaccinations and an anticipated enhanced duration of protection, might further be supported.SUMMARY/CONCLUSIONS: Efficiency of meningococcal vaccines for the different serogroups in CAD pts varies significantly and serological response analyses, especially in the currently recruiting CAD-Trials (BIVV009 and APL-2) addressing CI, are useful. By now, revaccination with the tetravalent conjugate vaccine (Menveo®) every 3 years is recommended. However, the associated risks with long-term CI are presently unknown and might be individually based on serologic response analyses to vaccination, which might even imply additional booster vaccination in pts on chronic CI. Physicians and pts must be vigilant for meningococcal infections at all times. A stand-by therapy with ciprofloxacin 750 mg p.o. in case of signs of meningococcal infection should be recommended with immediate medical evaluation and treatment. The availability of the novel vaccines covering serogroup B (Bexsero®, Trumenba®) may further reduce the risk of infections and should be mandatory in these pts, despite no current test exists to measure serologic response to meningococcal serogroup B on chronic CI. [Display omitted] DisclosuresDuehrsen:AbbVie: Consultancy, Honoraria; Amgen: Research Funding; Celgene: Honoraria, Research Funding; Gilead: Consultancy, Honoraria; Roche: Honoraria, Research Funding; Janssen: Honoraria. Röth:Novartis: Consultancy, Honoraria, Research Funding; Amgen: Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Bioverativ: Consultancy, Honoraria; Alexion Pharmaceuticals, Inc.: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding.

Comparison of synbiotic beverages produced from riceberry malt extract using selected free and encapsulated probiotic lactic acid bacteria

There has been much recent interest in probiotic products for lactose-intolerant consumers. This research developed a non-dairy synbiotic beverage from riceberry malt extract (RME). The objectives of the study were to select suitable lactic acid bacteria (LAB) and to compare the stabilities of products produced from free and encapsulated cells. Five LAB (Enterococcus faecalis N1-33, Lactobacillus acidophilus TISTR450, Lactobacillus johnsonii KUN119-2, Lactobacillus plantarum TC24 and Lactobacillus reuteri KUB-AC5) were tested for their ability to grow in RME, their survival under simulated gastrointestinal tract conditions and their antimicrobial activity. L. plantarum TC24 had the greatest probiotic potential. Comparisons of free versus encapsulated cell growth rates and their respective stabilities were carried out at two storage temperatures (8 °C and 30 °C) for 31 d. Calcium alginate encapsulation improved the survivability of L. plantarum TC24 under gastrointestinal tract conditions. However, the same treatment did not affect survivability under fermentation and storage conditions. Both free and encapsulated cell products could be stored at 8 °C for 15 d and the products retained viable cells at a level of 9 log colony forming units/mL. The encapsulated cell product was less preferable in consumer tests than the free cell product. The results suggested that RME has potential as a raw material for the production of nondairy synbiotic items for human consumption.

Two Vaccines for Staphylococcus aureus Induce a B-Cell-Mediated Immune Response.

Staphylococcus aureus causes severe disease in humans for which no licensed vaccine exists. A novel S.aureus vaccine (SA4Ag) is in development, targeting the capsular polysaccharides (CPs) and two virulence-associated surface proteins. Vaccine-elicited antibody responses to CPs are efficacious against serious infection by other encapsulated bacteria. Studies of natural S.aureus infection have also shown a role for TH17 and/or TH1 responses in protection. Single-antigen vaccines, including CPs, have not been effective against S.aureus; a multiantigen vaccine approach is likely required. However, the impact of addition of protein antigens on the immune response to CPs has not been studied. Here, the immune response induced by a bivalent CP conjugate vaccine (to model the established mechanism of action of vaccine-induced protection against Gram-positive pathogens) was compared to the response induced by SA4Ag, which contains both CP conjugates and protein antigens, in cynomolgus macaques. Microengraving, flow cytometry, opsonophagocytic assays, and Luminex technology were used to analyze the B-cell, T-cell, functional antibody, and innate immune responses. Both the bivalent CP vaccine and SA4Ag induced cytokine production from naive cells and antigen-specific memory B-cell and functional antibody responses. Increases in levels of circulating, activated T cells were not apparent following vaccination, nor was a TH17 or TH1 response evident. However, our data are consistent with a vaccine-induced recruitment of T follicular helper (TFH) cells to lymph nodes. Collectively, these data suggest that the response to SA4Ag is primarily mediated by B cells and antibodies that abrogate important S.aureus virulence mechanisms.IMPORTANCEStaphylococcus aureus causes severe disease in humans for which no licensed vaccine exists. A novel vaccine is in development that targets multiple elements of the bacteria since single-component vaccines have not shown efficacy to date. How these multiple components alter the immune response raised by the vaccine is not well studied. We found that the addition of two protein components did not alter substantially the antibody responses raised with respect to function or mobilization of B cells. There was also not a substantial change in the activity of T cells, another part of the adaptive response. This study showed that protection by this vaccine may be mediated primarily by antibody protection.

Development of alginate-pectin microparticles with dairy whey using vibration technology: Effects of matrix composition on the protection of Lactobacillus spp. from adverse conditions

In this study, lactic acid bacteria with probiotic potential, including Lactobacillus plantarum ATCC8014, L. paracasei ML33 and L. pentosus ML82, were encapsulated with whey-alginate-pectin (WAP) or whey permeate-alginate-pectin (PAP) by an extrusion process using vibrational technology, with the resulting microparticles assessed for their resistance to adverse conditions. The aim was to assess the effect of the encapsulation wall materials on the viability of microorganisms, the encapsulation, refrigerated storage and simulated gastrointestinal tract conditions, the kinetic parameters of acidification, and the morphology of microparticles. The bacteria encapsulated with the WAP wall material were adequately protected. Furthermore, after three months of storage at 4 °C, the encapsulated bacteria exhibited a cell viability of >6 log CFU mL−1. In addition, the encapsulated L. plantarum ATCC8014 and L. pentosus ML82 isolates exhibited the highest viability at the end of the storage period among the assayed isolates. Encapsulated bacteria showed greater resistance to acidic conditions than unencapsulated bacteria when exposed to simulated gastrointestinal tract conditions. The maximum rate of milk acidification by encapsulated Lactobacillus spp. was approximately three-fold lower than that observed for unencapsulated bacteria. The resulting size of the microparticles generated using both combinations of wall materials used was approximately 150 μm. The cheese whey and whey permeate combined with alginate and pectin to adequately encapsulate and protect Lactobacillus spp. from the adverse conditions of the simulated gastrointestinal tract and from refrigeration storage temperatures. Furthermore, the sizes of the obtained microparticles indicated that the encapsulated materials are suitable for being incorporated into foods without changing their sensory properties.

Human apolipoprotein E as a reservoir of cryptic bioactive peptides: The case of ApoE 133-167.

Bioactive peptides derived from the receptor-binding region of human apolipoprotein E have previously been reported. All these peptides, encompassing fragments of this region or designed on the basis of short repeated cationic sequences identified in the same region, show toxic activities against a broad spectrum of bacteria and interesting immunomodulatory effects. However, the ability of these molecules to exert antibiofilm properties has not been described so far. In the present work, we report the characterization of a novel peptide, corresponding to residues 133 to 167 of human apolipoprotein E, here named ApoE (133-167). This peptide, besides presenting interesting properties comparable with those reported for other ApoE-derived peptides, such as a direct killing activity against a broad spectrum of bacteria or the ability to downregulate lipopolysaccharide-induced cytokine release, is also endowed with significant antibiofilm properties. Indeed, the peptide is able to strongly affect the formation of the extracellular matrix and also the viability of encapsulated bacteria. Noteworthy, ApoE (133-167) is not toxic toward human and murine cell lines and is able to assume ordered conformations in the presence of membrane mimicking agents. Taken together, collected evidences about biological and structural properties of ApoE (133-167) open new perspectives in the design of therapeutic agents based on human-derived bioactive peptides.

Industrially-Scalable Microencapsulation of Plant Beneficial Bacteria in Dry Cross-Linked Alginate Matrix.

Microencapsulation of plant-beneficial bacteria, such as pink pigmented facultative methylotrophs (PPFM), may greatly extend the shelf life of these Gram-negative microorganisms and facilitate their application to crops for sustainable agriculture. A species of PPFM designated Methylobacterium radiotolerans was microencapsulated in cross-linked alginate microcapsules (CLAMs) prepared by an innovative and industrially scalable process that achieves polymer cross-linking during spray-drying. PPFM survived the spray-drying microencapsulation process with no significant loss in viable population, and the initial population of PPFM in CLAMs exceeded 1010 CFU/g powder. The PPFM population in CLAMs gradually declined by 4 to 5 log CFU/g over one year of storage. The extent of alginate cross-linking, modulated by adjusting the calcium phosphate content in the spray-dryer feed, did not influence cell viability after spray-drying, viability over storage, or dry particle size. However, particle size measurements and light microscopy of aqueous CLAMs suggest that enhanced crosslinking may limit the release of encapsulated bacteria. This work demonstrates an industrially scalable method for producing alginate-based inoculants that may be suitable for on-seed or foliar spray applications.

Development and physico-chemical characterization of microencapsulated bifidobacteria in passion fruit juice: A functional non-dairy product for probiotic delivery

The aim of this study was to produce a powdered probiotic passion fruit juice, in order to develop a new non-dairy probiotic beverage. For this purpose, passion fruit juice added with Bifidobacterium animalis ssp. lactis BB-12 was microencapsulated by spray drying using maltodextrin and/or inulin as encapsulating agents. The microcapsules obtained were characterized in relation to their morphological, physical and thermogravimetric properties after spray drying. The viability of probiotic microorganism, as well as the powders’ moisture content, water activity, solubility and color were evaluated throughout 30 days of storage at 25 °C and 4 °C. The storage at 4 °C resulted in a better maintenance of probiotic viability throughout the storage period. During storage at 25 °C, the sample made only with maltodextrin showed loss of viability of the bifidobacteria while the sample made with inulin offered better protection to the encapsulated bacteria. The different carrier agents affected the morphology and the particle size of the microcapsules. All the probiotic juice powders had similar flow characteristics. The use of maltodextrin resulted in higher values for moisture content and water activity. Throughout storage, an increase in moisture content and water activity was noted for all the samples. All the powders showed high solubility indexes. An increase in luminosity and a concurrent reduction in b* values throughout storage was noted for all the juice powder formulations at both temperatures, but more markedly at 25 °C. The results of the thermal analysis showed that both encapsulating agents improved the stability of the passion fruit juice.

USE OF WHEY PROTEIN FOR ENCAPSULATION AND CONTROLLED RELEASE OF PROBIOTIC FROM PROTEIN MICROENCAPSULE IN EX VIVO PORCINE GASTROINTESTINAL CONTENTS

The aim of this study was to evaluate the efficacy of whey protein isolate (WPI) as an encapsulation matrix for improvement of L. fermentum 39-183 viability to low pH and bile and releasing the encapsulated bacteria in ex vivo porcine gastrointestinal (GI) contents. 1g of protein microcapsules (≈ 108 CFU of L. fermentum 39-183 or E. coli GFP+) were incubated in ex vivo porcine GI contents (9 mL) under anaerobic conditions at 370C. Results showed that there was higher than 86% cell survival for encapsulated L. fermentum 39-183 after 3 h incubation in pH 2.0, whereas free cell experienced complete viability loss. Encapsulated L. fermentum 39-183 showed only about 0.86 log reduction for all bile salt levels tested (0.5 ÷ 2.0%), while 3.34 log decrease of free cell after 6 h of incubation. There was almost a complete release (3.9 x 108 CFU) of microencapsulated bacteria in the ileal contents within 2 h, while there was no significant release of encapsulated bacteria in the gastric contents even after 8 h of incubation. This study led to the development and design of a protein capsulation for reinforced probiotic protection during the stressful conditions of gastric and controlled release at a defined location.

Can partial splenectomy preserve humoral immunity in pediatric patients? Risks and benefits of partial splenectomy

The spleen plays an important role in re-moving normal and abnormal cells from the blood and in providing an immuno-logic response to encapsulated bacteria. Surgical splenectomy provides effective treatment for several pediatric disorders, such as congenital and acquired hemolytic anemias, abdominal traumas and immu-nological and metabolic disorders, but it is associated with an immediate and life-long risk of overwhelming infection. An alternative to conventional splenectomy is partial splenectomy, recommended espe-cially in children younger than 5 years of age. Recommendations for the prevention of overwhelming post-total splenectomy infection include: Pneumococcal, Haemo-philus influenzae type B and Meningococ-cal immunizations, antimicrobial prophy-laxis and prompt antibiotic treatment of acute febrile illness; conversely, there is no clear evidence indicating&nbsp;which preven-tion measures are to be performed in pa-tients undergoing partial splenectomy.

Application of expanded perlite encapsulated bacteria and growth media for self-healing concrete

Self-healing concrete based on calcium carbonate precipitation induced through bacterial activity has been investigated in recent years by teams around the world. For the first time, optimisation of the self-healing performance was considered in terms of the number of bacterial spores required, the concentration and composition of nutrients and precursors, and whether a two-component system was likely to efficiently produce self-healing in concrete. This information is required if efficient and cost-effective self-healing systems based on bacterial activity are to be implemented. For this research, coated expanded perlite was used to immobilise bacterial spores and encapsulate nutrients as two separate components for self-healing concrete. Self-healing capacity was evaluated by imaging and by initial surface absorption of water. The results indicated that healing could be achieved when coated expanded perlite containing self-healing agents was used as a 20% replacement of fine aggregate and if a suitable ratio of spores to calcium acetate was provided. This research is the first to show that self-healing is not simply a requirement of having sufficient healing compounds (e.g. calcium acetate) but that a minimal number of bacterial spores are also required to ensure that sufficient cells take part in the healing process.

Development of a multiplexed opsonophagocytic killing assay (MOPA) for group B Streptococcus

ABSTRACTGroup B Streptococcus (GBS) is a leading cause of sepsis in infants as well as chorioamnionitis in pregnant women. Opsonophagocytic killing assays (OPAs) are an essential technique in vaccine studies of encapsulated bacteria for estimating serotype-specific functional antibody levels in vitro. Here, we developed a three-fold multiplexed OPA (MOPA) to enable practical, large-scale assessment of GBS vaccine immunogenicity, including against serotypes Ia, III, and V. First, three target bacteria strains resistant to streptomycin, spectinomycin, or kanamycin were generated by natural selection through exposure to increasing antibiotic concentrations. Since a high level of nonspecific killing (NSK) of serotype V was observed in a 12.5% baby rabbit complement (BRC) solution, the BRC concentration was optimized. The final GBS-MOPA BRC concentration was 9%, which resulted in less than 20% NSK. The specificity was measured by preabsorbing serum with inactivated GBS. The opsonic index (OI) of preabsorbed serum with the homologous serotype GBS was significantly reduced in all three serotypes tested. The accuracy of the MOPA was compared with that of a single OPA (SOPA) with 35 serum samples. The OIs of the MOPA correlated well with those of the SOPA, and the r2 values were higher than 0.950 for all three serotypes. The precision of the MOPA assay was assessed in five independent experiments with five serum samples. The inter-assay precision of the GBS-MOPA was 12.5% of the average coefficient of variation. This is the first report to develop and standardize a GBS-MOPA, which will be useful for GBS vaccine development and evaluation.