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Social bees harbor a community of gut mutualistic bacteria, among which bifidobacteria occupy an important niche. Recently, four novel species have been isolated from guts of different bumblebees, thus allowing to suppose that a core bifidobacterial population may be present in wild solitary bees. To date there is sparse information about bifidobacteria in solitary bees such as Xylocopa and Osmia spp., this study is therefore focused on the isolation and characterization of bifidobacterial strains from solitary bees, in particular carpenter bee (Xylocopa violacea), builder bee (Osmia cornuta), and red mason bee (Osmia rufa). Among the isolates from Osmia spp. no new species have been detected whereas among Xylocopa isolates four strains (XV2, XV4, XV10, XV16) belonging to putative new species were found. Isolated strains are Gram-positive, lactate- and acetate-producing and possess the fructose-6-phosphate phosphoketolase enzyme. Full genome sequencing and genome annotation were performed for XV2 and XV10. Phylogenetic relationships were determined using partial and complete 16S rRNA sequences and hsp60 restriction analysis that confirmed the belonging of the new strains to Bifidobacterium genus and the relatedness of the strains XV2 and XV10 with XV16 and XV4, respectively. Phenotypic tests were performed for the proposed type strains, reference strains and their closest neighbor in the phylogenetic tree. The results support the proposal of two novel species Bifidobacterium xylocopae sp. nov. whose type strain is XV2 (=DSM 104955 T =LMG 30142 T ), reference strain XV16 and Bifidobacterium aemilianum sp. nov. whose type strain is XV10 (=DSM 104956 T =LMG 30143 T ), reference strain XV4., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

C. jejuni is considered a food safety concern to both public health authorities and consumers since it is the leading bacterial cause of food-borne gastroenteritis in humans. A high incidence of C. jejuni in broiler flocks is often correlated to pathogen recovery in retail poultry meat, which is the main source of human infection. In this work broiler chickens were fed with a synbiotic product mixed with conventional feed using two different administration strategies. The synbiotic was formulated with the microencapsulated probiotic Bifidobacterium longum PCB133 and a xylo-oligosaccharide (XOS). 1-day old chicks were infected with C. jejuni strain M1 (10 5 cells) and the synbiotic mixture was then administered starting from the first and the 14th day of chicken life (for animal groups GrpC and GrpB respectively). The goal of this study was to monitor C. jejuni load at caecum level at different sampling time by real-time PCR, identifying the best administration strategy. The microbiological analysis of the caecal content also considered the quantification of Campylobacter spp., Bifidobacterium spp. and B. longum. The supplemented synbiotic was more successful in reducing C. jejuni and Campylobacter spp. when administered lifelong, compared to the shorter supplementation (GrpB). Bifidobacterium spp. quantification did not show significant differences among treatments and B. longum PCB133 was detected in both supplemented groups evidencing the successful colonization of the strain. Moreover, the samples of the control group (GrpA) and GrpC were analysed with PCR-denaturing gradient gel electrophoresis (PCR-DGGE) to compare the caecal microbial community profiles at the beginning and at the end of the trial. Pattern analysis evidenced the strong influence of the early synbiotic supplementation, although a physiological change in the microbial community, occurring during growth, could be observed. Experimental results demonstrate that the synbiotic approach at farm level can be an effective strategy, combined with biosecurity measures, to improve the safety of poultry meat., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: The effect of intrapartum antibiotic prophylaxis (IAP) for group B Streptococcus (GBS) on bacterial colonization of the infant's gut has not been investigated extensively. We aimed to evaluate the effect of IAP on gut microbiota in healthy term infants, also exploring the influence of type of feeding., Methods: Healthy term infants, whose mothers had been screened for GBS in late gestation, were divided into 2 groups: infants born to GBS-positive mothers who had received IAP versus controls. Neonatal fecal samples were collected at 7 and 30 days of life; DNA was extracted, and quantification of selected microbial groups (Lactobacillus spp, Bifidobacterium spp, and Bacteroides fragilis group) was performed by real-time PCR., Results: A total of 84 infant-mother pairs were recruited. Bifidobacteria count was significantly lower in the IAP group at 7 days of life (median [interquartile range] 6.01 Log colony-forming unit per gram [5.51-6.98] vs 7.80 [6.61-8.26], P = 0.000). No differences in Bifidobacteria count at 30 days or in Lactobacilli and B fragilis counts at any time point were documented. Furthermore, at 7 days of life, infants who had not received IAP and were exclusively human milk-fed had higher counts of Bifidobacteria. Regardless of IAP treatment, infants fed exclusively human milk had higher Lactobacillus spp counts both at 7 and 30 days of life., Conclusions: IAP alters gut microflora by reducing the count of Bifidobacteria, which is further affected in infants receiving formula feeding. Whether these alterations could have long-term consequences on health and disease requires further investigation.

Background: Increasing evidence suggests that not only genetics, but also environmental factors like gut microbiota dysbiosis play an important role in the pathogenesis of celiac disease (CD)., Aim: The aim of our study was to investigate the effect of two probiotic strains Bifidobacterium breve BR03 and B. breve B632 on serum production of anti-inflammatory cytokine interleukin 10 (IL-10) and pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) in children with CD., Methods: The study was a double-blinded, placebo-controlled trial that included 49 children with CD on gluten-free diet (GFD) randomized into two groups and 18 healthy children in the control group. The first group (24 children with CD) daily received B. breve BR03 and B632 (2 × 10(9) colony-forming units) and the second group (25 children with CD) received placebo for 3 months., Results: TNF-α levels were significantly decreased in the first group after receiving B. breve for 3 months. On follow-up, 3 months after receiving probiotics, TNF-α levels increased again. Children with CD who were on GFD for less than 1 year showed similar baseline TNF-α levels as children who were on GFD for more than 1 year. IL-10 levels were in all groups of patients below detection level., Conclusions: Probiotic intervention with B. breve strains has shown a positive effect on decreasing the production of pro-inflammatory cytokine TNF-α in children with CD on GFD.

Several factors are known to influence the early colonization of the gut in newborns. Among them, the use of antibiotics on the mother during labor, referred to as intrapartum antibiotic prophylaxis (IAP), has scarcely been investigated, although this practice is routinely used in group B Streptococcus (GBS)-positive women. This work is therefore aimed at verifying whether IAP can influence the main microbial groups of the newborn gut microbiota at an early stage of microbial establishment. Fifty-two newborns were recruited: 26 born by mothers negative to GBS (control group) and 26 by mothers positive to GBS and subjected to IAP with ampicillin (IAP group). Selected microbial groups (Lactobacillus spp., Bidobacterium spp., Bacteroides fragilis, Clostridium difficile, and Escherichia coli) were quantified with real-time PCR on DNA extracted from newborn feces. Further analysis was performed within the Bidobacterium genus by using DGGE after amplification with genus-specific primers. Results obtained showed a significant decrease of the bifidobacteria counts after antibiotic treatment of the mother. Bifidobacteria were found to be affected by IAP not only quantitatively but also qualitatively. In fact, IAP determined a decrement in the frequency of Bidobacterium breve, Bidobacterium bifidum, and Bidobacterium dentium with respect to the control group. Moreover, this study has preliminarily evaluated that some bifidobacterial strains, previously selected for use in infants, have antibacterial properties against GBS and are therefore potential candidates for being applied as probiotics for the prevention of GBS infections.

Infant colic is a common gastrointestinal disorder of newborns, mostly related to imbalances in the composition of gut microbiota and particularly to the presence of gas-producing coliforms and to lower levels of Bifidobacteria and Lactobacilli. Probiotics could help to contain this disturbance, with formulations consisting of Lactobacillus strains being the most utilized. In this work, the probiotic strain Bifidobacterium breve B632 that was specifically selected for its ability to inhibit gas-producing coliforms, was challenged against the Enterobacteriaceae within continuous cultures of microbiota from a 2-month-old colicky infant. As confirmed by RAPD-PCR fingerprinting, B. breve B632 persisted in probiotic-supplemented microbiota cultures, accounting for the 64% of Bifidobacteria at the steady state. The probiotic succeeded in inhibiting coliforms, since FISH and qPCR revealed that the amount of Enterobacteriaceae after 18 h of cultivation was 0.42 and 0.44 magnitude orders lower (P < 0.05) in probiotic-supplemented microbiota cultures than in the control ones. These results support the possibility to move to another level of study, that is, the administration of B. breve B632 to a cohort of colicky newborns, in order to observe the behavior of this strain in vivo and to validate its effect in colic treatment.

This review is aimed at describing the most recent advances in the gut microbiota composition of newborns and infants with a particular emphasis on bifidobacteria. The newborn gut microbiota is quite unstable, whereas after weaning, it becomes more stable and gets closer to the typical adult microbiota. The newborn and infant gut microbiota composition is impaired in several enteric and non-enteric pathologies. The core of this review is the description of the most recent documented applications of bifidobacteria to newborns and infants for their prevention and treatment. Acute diarrhea is the most studied disease for which bifidobacteria are applied with great success, Bifidobacterium longum and Bifidobacterium breve being the most applied species. Moreover, the most recent updates in the use of bifidobacteria for the prevention and treatment of pathologies typical of newborns, such as necrotizing enterocolitis, colics, and streptococcal infections, are presented. In addition, a number of not strictly enteric pathologies have in recent years evidenced a strict correlation with an aberrant gut microbiota in infants, in particular showing a reduced level of bifidobacteria. These diseases represent new potential opportunities for probiotic applications. Among them, allergic diseases, celiac disease, obesity, and neurologic diseases are described in this review. The preliminary use of bifidobacteria in in vitro systems and animal models is summarized as well as preliminary in vivo studies. Only after validation of the results via human clinical trials will the potentiality of bifidobacteria in the prevention and cure of these pathologies be definitely assessed.

Background: Bifidobacterium represents one of the largest genus within the Actinobacteria, and includes at present 32 species. These species share a high sequence homology of 16S rDNA and several molecular techniques already applied to discriminate among them give ambiguous results., Results: This work illustrates a simple and cheap molecular tool for the identification of Bifidobacterium species. The hsp60 universal primers were used in a simple PCR procedure for the direct amplification of 590 bp of the hsp60 sequence. The in silico restriction analysis of bifidobacterial hsp60 partial sequences allowed the identification of a single endonuclease (HaeIII) able to provide different PCR-restriction fragment length polymorphism (RFLP) patterns in the Bifidobacterium spp. type strains evaluated. The electrophoretic analyses allowed to confirm the different RFLP patterns., Conclusions: The developed PCR-RFLP technique resulted in efficient discrimination of the tested species and subspecies and allowed the construction of a dichotomous key in order to differentiate the most widely distributed Bifidobacterium species as well as the subspecies belonging to B. pseudolongum and B. animalis.

Several studies support the use of probiotics for the treatment of minor gastrointestinal problems in infants. Positive effects on newborn colics have been evidenced after administration of Lactobacillus strains, whereas no studies have been reported regarding the use of bifidobacteria for this purpose. This work was therefore aimed at the characterization of Bifidobacterium strains capable of inhibiting the growth of pathogens typical of the infant gastrointestinal tract and of coliforms isolated from colic newborns. Among the 46 Bifidobacterium strains considered, 16 showed high antimicrobial activity against potential pathogens; these strains were further characterized from a taxonomic point of view, for the presence and transferability of antibiotic resistances, for citotoxic effects and adhesion to nontumorigenic gut epithelium cell lines. Moreover, their ability to stimulate gut health by increasing the metabolic activity and the immune response of epithelial cells was also studied. The examination of all these features allowed to identify three Bifidobacterium breve strains and a Bifidobacterium longum subsp. longum strain as potential probiotics for the treatments of enteric disorders in newborns such as infantile colics. A validation clinical trial involving the selected strains is being planned.

Background: Wheat grains are a rich source of dietary fibres, particularly in the western human diet. Many of the health effects attributed to dietary fibres are believed to be related to their microbial fermentation in the gut. This study evaluated the ability of two potentially probiotic strains, Lactobacillus plantarum L12 and Bifidobacterium pseudocatenulatum B7003, to ferment soluble dietary fibres (SDFs) from modern and ancient durum-type wheat grains., Results: Fibre microbial utilisation was highly variable and dependent on the strain. SDFs from the varieties Svevo and Solex supported the growth of L. plantarum L12 the best, whereas those from the varieties Anco Marzio, Solex and Kamut(®) Khorasan were good carbohydrate substrates for B. pseudocatenulatum B7003. The highest prebiotic activity scores (describing the extent to which prebiotics support selective growth of probiotics) for B7003 were obtained with SDFs from the varieties Solex (0.57), Kamut(®) Khorasan (0.56) and Iride (0.55), whereas for L12 the highest scores were achieved with the varieties Orobel (0.63), Kamut(®) Khorasan (0.56) and Solex (0.53)., Conclusion: The present study has identified some SDFs from durum-type wheat grains as suitable prebiotic substrates for the selective proliferation of B. pseudocatenulatum B7003 and L. plantarum L12 in vitro. The results provide the basis for the potential utilisation of wheat-based prebiotics as a component of synbiotic formulations., (Copyright © 2012 Society of Chemical Industry.)

With the ban of dietary antimicrobial agents, the use of probiotics, prebiotics and synbiotics has attracted a great deal of attention in order to improve intestinal health and control food-borne pathogens, which is an important concern for the production of safe meat and meat products. Recently, Campylobacter jejuni has emerged as a leading bacterial cause of food-borne gastroenteritis in humans, and epidemiological evidences indicate poultry and poultry products as the main source of human infection. This work aimed at the development of a synbiotic mixture capable of modulating the gut microbiota of broiler chickens to obtain an increase of the beneficial bacteria (i.e. bifidobacteria, lactobacilli) and a competitive reduction of C. jejuni. The prebiotic compound used in the mixture was chosen after an in vivo trial: a fructooligosaccharide and a galactooligosaccharide were separately administered to broilers mixed with normal feed at a concentration of 0.5% and 3%, respectively. Quantitative PCR on DNA extracted from fecal samples revealed a significant (p<0.05) increase of Bifidobacterium spp. in broilers treated with the galactooligosaccharide, coupled to a decrease (p<0.05) of Campylobacter spp. The galactooligosaccharide was then combined with a probiotic Bifidobacterium strain (B. longum subsp. longum PCB133), possessing in vitro antimicrobial activity against C. jejuni. The strain was microencapsulated in a lipid matrix to ensure viability into the feed and resistance to stomach transit. Finally, the synbiotic mixture was administered to broiler chickens for 14 days mixed with normal feed in order to have an intake of 10(9)CFU of PCB133/day. Bifidobacterium spp., Lactobacillus spp., Campylobacter spp., B. longum subsp. longum and C. jejuni were quantified in fecal samples. PCB133 was recovered in feces of all animals. C. jejuni concentration in poultry feces was significantly (p<0.05) reduced in chickens administered with the synbiotic mixture. This study allowed to highlight the positive effect of the synbiotic approach for C. jejuni reduction in broiler chickens, which is of fundamental importance for the safety of poultry meat consumers., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The genus Serratia harbors opportunistic pathogenic species, among which Serratia marcescens is pathogenic for honeybees although little studied. Recently, virulent strains of S. marcescens colonizing the Varroa destructor mite's mouth were found vectored into the honeybee body, leading to septicemia and death. Serratia also occurs as an opportunistic pathogen in the honeybee's gut with a low absolute abundance. The Serratia population seems controlled by the host immune system, but its presence may represent a hidden threat, ready to arise when honeybees are weakened by biotic and abiotic stressors. To shed light on the Serratia pathogen, this research aims at studying Serratia's development dynamics in the honeybee body and its interactions with the co-occurring fungal pathogen Vairimorpha ceranae. Firstly, the degree of pathogenicity and the ability to permeate the gut epithelial barrier of three Serratia strains, isolated from honeybees and belonging to different species (S. marcescens, Serratia liquefaciens, and Serratia nematodiphila), were assessed by artificial inoculation of newborn honeybees with different Serratia doses (104, 106, and 108 cells/mL). The absolute abundance of Serratia in the gut and in the hemocoel was assessed in qPCR with primers targeting the luxS gene. Moreover, the absolute abundance of Serratia was assessed in the gut of honeybees infected with V. ceranae at different development stages and supplied with beneficial microorganisms and fumagillin. Our results showed that all tested Serratia strains could pass through the gut epithelial barrier and proliferate in the hemocoel, with S. marcescens being the most pathogenic. Moreover, under cage conditions, Serratia better proliferates when a V. ceranae infection is co-occurring, with a positive and significant correlation. Finally, fumagillin and some of the tested beneficial microorganisms could control both Serratia and Vairimorpha development. Our findings suggest a correlation between the two pathogens under laboratory conditions, a co-occurring infection that should be taken into consideration by researches when testing antimicrobial compounds active against V. ceranae, and the related honeybees survival rate. Moreover, our findings suggest a positive control of Serrata by the environmental microorganism Apilactobacillus kunkeei in a in vivo model, confirming the potential of this specie as beneficial bacteria for honeybees. [ABSTRACT FROM AUTHOR]

Pollinators, including solitary bees, are drastically declining worldwide. Among the factors contributing to this decline, bee pathogens and different land uses are of relevance. The link between the gut microbiome composition and host health has been recently studied for social pollinators (e.g. honeybees), whereas the information related to solitary bees is sparse. This work aimed at the characterization of the gut microbiome of the solitary bees Xylocopa augusti, Eucera fervens and Lasioglossum and attempted to correlate the gut microbial composition with the presence and load of different pathogens and land uses. Solitary bees were sampled in different sites (i.e. a farm, a natural reserve, and an urban plant nursery) showing different land uses. DNA was extracted from the gut, 16S rRNA gene amplified and sequenced. Eight pathogens, known for spillover from managed bees to wild ones, were quantified with qPCR. The results showed that the core microbiome profile of the three solitary bees significantly varied in the different species. Pseudomonas was found as the major core taxa in all solitary bees analyzed, whereas Lactobacillus, Spiroplasma and Sodalis were the second most abundant taxa in X. augusti, E. fervens and Lasioglossum, respectively. The main pathogens detected with qPCR were Nosema ceranae, Nosema bombi and Crithidia bombi, although differently abundant in the different bee species and sampling sites. Most microbial taxa did not show any correlation with the land use, apart from Snodgrassella and Nocardioides, showing higher abundances on less anthropized sites. Conversely, the pathogens species and load strongly affected the gut microbial composition, with Bifidobacterium, Apibacter, Serratia, Snodgrassella and Sodalis abundance that positively or negatively correlated with the detected pathogens load. Therefore, pathogens presence and load appear to be the main factor shaping the gut microbiome of solitary bees in Argentina. [ABSTRACT FROM AUTHOR]

Fourier transform infrared (FTIR) spectroscopy, a technology traditionally used in chemistry to determine the molecular composition of a wide range of sample types, has gained growing interest in microbial typing. It is based on the different vibrational modes of the covalent bonds between atoms of a given sample, as bacterial cells, induced by the absorption of infrared radiation. This technique has been largely used for the study of pathogenic species, especially in the clinical field, and has been proposed also for the typing at different subspecies levels. The high throughput, speed, low cost, and simplicity make FTIR spectroscopy an attractive technique also for industrial applications, in particular, for probiotics. The aim of this study was to compare FTIR spectroscopy with established genotyping methods, pulsed-field gel electrophoresis (PFGE), whole-genome sequencing (WGS), and multilocus sequence typing (MLST), in order to highlight the FTIR spectroscopy potential discriminatory power at strain level. Our study focused on bifidobacteria, an important group of intestinal commensals generally recognized as probiotics. For their properties in promoting and maintaining health, bifidobacteria are largely marketed by the pharmaceutical, food, and dairy industries. Strains belonging to Bifidobacterium longum subsp. longum and Bifidobacterium animalis subsp. lactis were taken into consideration together with some additional type strains. For B. longum subsp. longum , it was possible to discriminate the strains with all the methods used. Although two isolates were shown to be strictly phylogenetically related, constituting a unique cluster, based on PFGE, WGS, and MLST, no clustering was observed with FTIR. For B. animalis subsp. lactis group, PFGE, WGS, and MLST were non-discriminatory, and only one strain was easily distinguished. On the other hand, FTIR discriminated all the isolates one by one, and no clustering was observed. According to these results, FTIR analysis is not only equivalent to PFGE, WGS, and MLST, but also for some strains, in particular, for B. animalis subsp. lactis group, more informative, being able to differentiate strains not discernible with the other two methods based on phenotypic variations likely deriving from certain genetic changes. Fourier transform infrared spectroscopy has highlighted the possibility of using the cell surface as a kind of barcode making tracing strains possible, representing an important aspect in probiotic applications. Furthermore, this work constitutes the first investigation on bifidobacterial strain typing using FTIR spectroscopy. [ABSTRACT FROM AUTHOR]

The faecal microbiota composition of infants born to mothers receiving intrapartum antibiotic prophylaxis with ampicillin against group B Streptococcus was compared with that of control infants, at day 7 and 30 of life. Recruited newborns were both exclusive breastfed and mixed fed, in order to also study the effect of dietary factors on the microbiota composition. Massive parallel sequencing of the V3-V4 region of the 16S rRNA gene and qPCR analysis were performed. Antibiotic prophylaxis caused the most marked changes on the microbiota in breastfed infants, mainly resulting in a higher relative abundance of Enterobacteriaceae, compared with control infants (52% vs. 14%, p = 0.044) and mixed-fed infants (52% vs. 16%, p = 0.13 NS) at day 7 and in a lower bacterial diversity compared to mixed-fed infants and controls. Bifidobacteria were also particularly vulnerable and abundances were reduced in breastfed (p = 0.001) and mixed-fed antibiotic treated groups compared to non-treated groups. Reductions in bifidobacteria in antibiotic treated infants were also confirmed by qPCR. By day 30, the bifidobacterial population recovered and abundances significantly increased in both breastfed (p = 0.025) and mixed-fed (p = 0.013) antibiotic treated groups, whereas Enterobacteriaceae abundances remained highest in the breastfed antibiotic treated group (44%), compared with control infants (16%) and mixed-fed antibiotic treated group (28%). This study has therefore demonstrated the short term consequences of maternal intrapartum antibiotic prophylaxis on the infant faecal microbial population, particularly in that of breastfed infants. [ABSTRACT FROM AUTHOR]

Different factors are known to influence the early gut colonization in newborns, among them the perinatal use of antibiotics. On the other hand, the effect on the baby of the administration of antibiotics to the mother during labor, referred to as intrapartum antibiotic prophylaxis (IAP), has received less attention, although routinely used in group B Streptococcus positive women to prevent the infection in newborns. In this work, the fecal microbiota of neonates born to mothers receiving IAP and of control subjects were compared taking advantage for the first time of high-throughput DNA sequencing technology. Seven different 16S rDNA hypervariable regions (V2, V3, V4, V6 + V7, V8, and V9) were amplified and sequenced using the Ion Torrent Personal Genome Machine. The results obtained showed significant differences in the microbial composition of newborns born to mothers who had received IAP, with a lower abundance of Actinobacteria and Bacteroidetes as well as an overrepresentation of Proteobacteria. Considering that the seven hypervariable regions showed different discriminant ability in the taxonomic identification, further analyses were performed on the V4 region evidencing in IAP infants a reduced microbial richness and biodiversity, as well as a lower number of bacterial families with a predominance of Enterobacteriaceae members. In addition, this analysis pointed out a significant reduction in Bifidobacterium spp. strains. The reduced abundance of these beneficial microorganisms, together with the increased amount of potentially pathogenic bacteria, may suggest that IAP infants are more exposed to gastrointestinal or generally health disorders later in age. [ABSTRACT FROM AUTHOR]

The capability of ten commercial fibers of selectively stimulating the growth of four Bifidobacterium strains were studied with the purpose of developing a synbiotic product for infants. Two galacto-oligosaccharides (GOS), one fructo-oligosaccharide (sc-FOS), four inulins with different polymerization degree (DP), a gluco-oligosaccharide, an arabinogalactan and a hydrolyzed guar gum were used (10 gl −1 ). The prebiotic score was calculated comparing the capability of the fibers of stimulating the growth of bifidobacteria compared to infant pathogens. GOS, sc-FOS, low DP inulin (oligofructose) and the gluco-oligosaccharide could stimulate growth. However, the fibers showing the highest prebiotic score were oligofructose (Orafti ® HIS), sc-FOS (Actilight ® 950P) and the GOS Vivinal ® . Lyophilized strain survival in simulated gastro-intestinal conditions was also assayed to define suitable ways of administration. Survival in gastric juice at pH 2.5 was poor, whereas it was higher at pH 4, a value closer to newborn pH. Microencapsulation in a lipid matrix ensured strain survival also at pH 2.5. Survival to 1 gl −1 bile salts was acceptable. The results allowed to conclude that Bifidobacterium breve B632 strain, in a lyophilized or microencapsulated form, has the potential for use in synbiotic products targeted to infants coupled to a mixture of GOS and FOS or oligofructose. [ABSTRACT FROM AUTHOR]

The growing concern on the antibiotic resistance spreading among bacteria has stimulated the search for valuable alternatives from plant sources. This study dealt with the potential use of hemp (Cannabis sativa L.) seeds extract to inhibit the growth of selected pathogenic enterobacteria and the biofilm formation by Staphylococcus aureus , representing severe risks of food-borne illnesses. Effects on probiotic bacteria were also examined. A double-staining viability/mortality assay was used to examine potential S. aureus membrane damage. Our results highlighted a selective antimicrobial activity of C. sativa extract against pathogenic strains and no inhibitory effects on the growth of probiotic strains belonging to the Bifidobacterium and Lactobacillus genera. This selective inhibition is of outmost importance for the maintenance of healthy gut microbiota. The double-staining assay showed that the C. sativa extract was capable of inhibiting the biofilm producer S. aureus ATCC 35556 strain; this antibacterial action was only partially linked to membrane damage. Biofilm formation was inhibited as well; inhibition occurs at lower concentration with respect to planktonic cells (0.5 mg/ml vs 1 mg/ml, respectively). Therefore, hemp seeds extracts represent a new exploitable and valuable antimicrobial and antibiofilm agent for the food and nutraceutical industry as a possible alternative to antibiotics/antibacterial compounds. Image 1 • Cannabis sativa L. seeds showed antimicrobial and antibiofilm activity. • C. sativa L. seeds selectively inhibit the growth of potentially pathogenic strains. • C. sativa L. seeds did not exert antimicrobial activity against probiotic bacteria. • C. sativa L. seeds inhibit the biofilm formation by Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Abstract: Campylobacteriosis is at present the most frequent zoonosis in humans and the main source is poultry meat contaminated by Campylobacter jejuni. An alternative and effective approach to antibiotic administration to livestock to reduce bacterial contamination is the use of probiotics, which can help to improve the natural defence of animals against pathogenic bacteria. In this study 55 lactic acid bacteria and bifidobacteria were screened for desirable properties for their application as probiotics against Campylobacter in poultry. All bacteria were examined for their antimicrobial activity against three C. jejuni strains. Strains exhibiting the highest anti-Campylobacter activity were examined for their survival in the gastro intestinal tract (low pH and presence of bile salts) and food/feed processing conditions (high temperature, high NaCl concentration and starvation) and basic safety aspects such as antibiotic susceptibility and hemolytic activity were studied. On the basis of these activities, two strains, namely Lactobacillus plantarum PCS 20 and Bifidobacterium longum PCB 133, were chosen for an in vivo trial in poultry. They were separately administered to healthy chickens in order to evaluate their capability of colonizing the GI tract of poultry and to estimate their effect on C. jejuni population. The results evidenced that L. plantarum PCS 20 was not present in poultry feces at detectable concentration, whereas B. longum PCB 133 significantly increased after two weeks of daily administration and its amount was still high after a wash-out period of 6days. In the same period, C. jejuni concentration in poultry feces was significantly reduced in chickens administered with B. longum PCB 133. Therefore, B. longum PCB 133, possessing interesting probiotic properties and a marked anti-Campylobacter activity both in vitro and in vivo, is an excellent candidate for being employed as additives to feed for poultry for the reduction of food-borne campylobacteriosis in humans. [Copyright &y& Elsevier]