Search

Introduction: The purpose of this study was to compare efficacy of a manual and an interactive power toothbrush in orthodontic patients by assessing periodontal indexes and bacterial content of saliva samples., Methods: Forty patients (20 females, 20 males; age range 12-18 years) with fixed orthodontic appliances were included in the study. The patients were randomly divided into two groups in a 1:1 ratio using sealed envelopes: group 1: manual toothbrush (Oral‑B Ortho Brush, Procter&Gamble Company, Dublin, Ireland), group 2: interactive power toothbrush (Oral‑B Genius 8900, Procter&Gamble Company, Marktheidenfeld, Germany). All participants were given the same toothpaste (Colgate Triple Action, Colgate-Palmolive, New York, NY, USA). The brushing procedure for each patient was described in detail, both orally and visually, utilizing a video demonstration. Plaque and bleeding index scores were recorded for both the lower and upper arches at the beginning of the study (T0) and at weeks 6 (T1) and 12 (T2). In addition, the numbers of Streptococcus (S.) mutans, Lactobacillus (L.) casei, and Porphyromonas (P.) gingivalis bacteria were determined using a real-time polymerase chain reaction (PCR) analysis in saliva samples collected at T0, T1, and T2 times. Mann-Whitney U test and Student's t test were used to compare data between the groups, and one-way analysis of variance (ANOVA) and Friedman tests were used to compare data from different time intervals for each group., Results: Plaque index values were greater in group 1 at T1 and T2, although there was no difference between the groups at T0. The gingival index scores of both groups were similar at T0, T1, and T2. While group 2 had a larger number of salivary S. mutans at T0 and T2, there was no significant difference between the groups at T1. At all three time points, there was no significant difference in salivary L. casei levels between the groups., Conclusions: Although the interactive power toothbrush was more effective at removing plaque than the manual toothbrush, the results of the gingival index did not reflect the plaque scores. The number of certain salivary bacteria and brush type did not appear to have a clear relationship., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Lead (Pb 2+ ) exposure cause a potential hazard to human health and the ecological environment; however, prevention and treatment of Pb 2+ toxicity remain problems. The aim of this study is to isolate a novel probiotic lead (Pb 2+ )-resistant Lactobacillus strain from the infant gut microbiota and to determine whether they have the probiotic properties and investigate its preventive and therapeutic effects in the early-life Pb 2+ exposure mouse model. In the present study, a total of 64 Pb 2+ -resistant colonies were isolated from the infant gut microbiota. Of these colonies, SYF-08, identified as Lacticaseibacillus casei, exhibited a Pb 2+ -binding capacity and Pb 2+ tolerance. The in vivo study showed that SYF-08 treatment could effectively reduce Pb 2+ levels in the blood, alleviate Pb 2+ enrichment in bone and brain tissues, and recover the intestinal and brain damage in both dams and offspring. SYF-08 treatment also improved the antioxidant index in the liver and kidney tissues, while increasing the diversity of the intestinal microbiota of the offspring. The results of the in vitro and in vivo studies suggest that SYF-08, isolated from infant fecal samples, is a promising candidate probiotic against Pb 2+ toxicity., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Biosurfactants are microbial surface-active compounds with antimicrobial and antioxidant activities that display a range of physiological functions. In this study, a strain isolated from a Cameroonian fermented milk "pendidam" and identified as Lactobacillus casei subsp. casei TM1B was used for biosurfactants production. The biosurfactants produced by L. casei TM1B with molasses as the substrate had a good surface (40.77 mN/m) and emulsifying (84.50%) activities. The scavenging of the ABTS +• radical (IC 50 value of 0.60 ± 0.03 mg/mL) by the biosurfactants was found to be higher than that of DPPH • radical (IC 50 value of 0.97 ± 0.13 mg/mL). The maximum chelating activity of biosurfactants (82.29%) was observed at 3.5 mg/mL. The biologically active compound of the biosurfactants produced by L. casei TM1B was identified as 2,5-O-methylrhamnofuranosyl-palmitate, a novel rhamnolipid-like biosurfactant by using chemical, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry, and NMR analysis. The biosurfactants were bactericidal against several Gram-negative and Gram-positive pathogens (minimum inhibitory concentration values ranged from 3.22 to 12.83 mg/mL), and scanning electron microscope analysis revealed bacterial cell walls and membranes as main targets., (© 2020 International Union of Biochemistry and Molecular Biology, Inc.)

Probiotics play an important role in health benefits on the host. However, they also possess potentials for infectivity or in situ toxin production; thus, requiring a comprehensive assessment of their safety. In this study, we report genomic characteristics of a newly isolated Lactobacillus casei IDCC 3451 from infant faeces. Phenotypic assays based on enzyme activities and carbohydrate fermentation profiles represented metabolic features of the strain. Safety evaluation for antimicrobial resistance, biogenic amines production and cytotoxicity to a murine mouse model suggested its safe use as a probiotic strain. Our findings on the genetic background of L. casei IDCC 3451 and its potential features provide a promising functional and safe probiotic strain for the human consumption., (© 2021 The Society for Applied Microbiology.)

Improving the nutrition of livestock is an important aspect of global food production sustainability. This study verified whether lactic acid bacteria (LAB) inoculant could promote ensiling characteristics, nutritive value, and in vitro enteric methane (CH 4 ) mitigation of forage sorghum (FS) mixture silage in attacking malnutrition in Zebu beef cattle. The FS at the soft dough stage, Cavalcade hay (CH), and cassava chip (CC) were obtained. The treatments were designed as a 4 × 2 factorial arrangement in a completely randomized design. Factor A was FS prepared without or with CH, CC, and CH + CC. Factor B was untreated or treated with Lactobacillus casei TH14. The results showed that all FS mixture silages preserved well with lower pH values below 4.0 and higher lactic acid contents above 56.4 g/kg dry matter (DM). Adding LAB boosted the lactic acid content of silages. After 24 h and 48 h of in vitro rumen incubation, the CC-treated silage increased in vitro DM digestibility (IVDMD) with increased total gas production and CH 4 production. The LAB-treated silage increased IVDMD but decreased CH 4 production. Thus, the addition of L. casei TH14 inoculant could improve lactic acid fermentation, in vitro digestibility, and CH 4 mitigation in the FS mixture silages.

The volatile components of milks fermented using traditional starter cultures (Streptococcus thermophilus and Lactobacillus bulgaricus) and probiotics (Lactobacillus lactis, Lactobacillus bifidus, Lactobacillus casei, and Lactobacillus plantarum) were investigated by means of gas chromatography-mass spectrometry (GC-MS) combined with simultaneous distillation extraction (SDE). A total of 53 volatile compounds were detected, being 10 aldehydes, 11 ketones, 10 acids, 11 hydrocarbons, 7 benzene derivatives, and 4 other compounds. The starter culture was found to significantly affect the composition of volatile components in the fermented milks. Ketones and hydrocarbons were the dominant compounds in milk before fermentation, while acids were dominant compounds in the fermented samples. Compared with probiotics, there was greater abundance of volatile components in fermented milks with traditional strains. The importance of each volatile compound was assessed on the basis of odor, thresholds, and odor activity values (OAVs). Of the volatile compounds, 31 of them were found to be odor-active compounds (OAV > 1). The component with the highest OAVs in most samples was (E,E)-2,4-decadienal. Heatmap analysis and principal component analysis were employed to characterize the volatile profiles of milks fermented by different starter cultures. The results could help to better understand the influence of starter cultures on the odor quality of milks.

Raw milk contains wide microbial diversity, composed mainly of lactic acid bacteria (LAB), which are used as probiotics in both human and animal husbandry. We isolated, characterized, and evaluated LAB from indigenous Bangladeshi raw milk to assess probiotic potential, including antagonistic activity (against Escherichia coli O157: H7, Enterococcus faecalis, Salmonella Typhimurium, Salmonella Enteritidis, and Listeria monocytogenes), survivability in simulated gastric juice, tolerance to phenol and bile salts, adhesion to ileum epithelial cells, auto- and co-aggregation, hydrophobicity, α-glucosidase inhibitory activity, and antibiotic susceptibility tests. The 4 most promising LAB strains showed probiotic potential and were identified as Lactobacillus casei, Lactobacillus plantarum (which produced plantaricin EF), Lactobacillus fermentum, and Lactobacillus paracasei. These strains inhibited all pathogens tested at various degrees, and competitively excluded pathogens with viable counts of 3.0 to 6.0 log cfu/mL. Bacteriocin, organic acids, and low-molecular-weight substances were mainly responsible for antimicrobial activity by the LAB strains. All 4 LAB strains were resistant to oxacillin and 3 were resistant to vancomycin and streptomycin, with multiple antibiotic resistance indices >0.2. After further in vivo evaluation, these LAB strains could be considered probiotic candidates with application in the food industry., (Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Siraitia grosvenorii fruit (SGF) has been used as a natural sweetener and traditional medicine in China for more than two centuries. This study evaluated the effect of SGF extract supplementation (0.5%, 1%, and 2%) on the chemical, microbial and sensory properties of probiotic yogurt. The antioxidant, angiotensin-converting-enzyme inhibitory (ACE-I) and antibacterial bioactivities were determined. SGF extract supplementation improved some of the chemical and physicochemical characteristics. Probiotic yogurt with the fruit extract had significantly more Lactobacillus casei and Lactobacillus bulgaricus, whereas there was no significant effect on the number of Streptococcus thermophiles. The bioactivities were significantly increased by SGF extract supplementation. Probiotic yogurt with 2% SGF extract showed the highest antioxidant, ACE-I, and antibacterial activities, whereas the one with 1% SGF extract conferred the highest sensory attributes score. Overall, SGF extract offers a promising option as a dietary supplement to produce novel dairy products that have high nutritional and bioactivity values., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: The traditional method of bacterial identification based on 16S rRNA is a widely used and very effective detection method, but this method still has some deficiencies, especially in the identification of closely related strains. A high homology with little differences is mostly observed in the 16S sequence of closely related bacteria, which results in difficulty to distinguish them by 16S rRNA-based detection method. In order to develop a rapid and accurate method of bacterial identification, we studied the possibility of identifying bacteria with other characteristic fragments without the use of 16S rRNA as detection targets., Results: We analyzed the potential of using cas (CRISPR-associated proteins) gene as a target for bacteria detection. We found that certain fragment located in the casx gene was species-specific and could be used as a specific target gene. Based on these fragments, we established a TaqMan MGB Real-time PCR method for detecting bacteria. We found that the method used in this study had the advantages of high sensitivity and good specificity., Conclusions: The casx gene-based method of bacterial identification could be used as a supplement to the conventional 16 s rRNA-based detection method. This method has an advantage over the 16 s rRNA-based detection method in distinguishing the genetic relationship between closely-related bacteria, such as subgroup bacteria, and can be used as a supplement to the 16 s rRNA-based detection method.

Hyperphosphatemia is a secondary issue associated with chronic kidney disorder. Use of phosphate binders and dialysis are the treatments for hyperphosphatemia, albeit with harmful side effects and high cost, respectively. A safer and healthier approach is attempted to administer phosphate-accumulating organisms (PAOs) from probiotics to prevent hyperphosphatemia. However, screening and isolation of PAOs are limited by inefficient enrichment of relevant metabolism and contamination. Therefore, we devised a novel strategy to isolate elite PAOs from Lactobacillus casei JCM 1134 and Bifidobacterium adolescentis JCM 1275 (previously reported PAOs). PAOs were first enriched for phosphate uptake and incubated in low-pH phosphate-free media to dormant non-PAOs, and then purified using Percoll density gradient centrifugation. Subsequently, elite PAOs were isolated from centrifuged pellet on a toluidine blue O-supplemented agar-based media. Using this technique, elite PAOs could not only be isolated, but also semi-quantitatively scored for their phosphate accumulation capabilities. Additionally, these scores correlated well with their accumulated phosphate values. The elite PAOs isolated from L. casei and B. adolescentis showed 0.81 and 0.70 [mg-phosphate/mg-dry cell], respectively (23- and 4.34-fold increase, respectively). Thus, our method can be used to successfully isolate elite PAOs, which might be of use to prevent hyperphosphatemia at early stages.

An aptamer-based strategy was developed for qualitative and quantitative analysis of viable Lactobacillus casei in dairy products. Three highly specific aptamers for L. casei were obtained using systematic evolution of ligands by exponential enrichment protocol using the whole bacterium cell as the target (cell-SELEX) facilitated by polyethyleneglycol and chitosan modified graphene oxide and complementary ring-mediated rolling circle amplification. Two aptamers, one for separating and enriching the L. casei cells and the other for generating fluorescence signals, were employed to develop an aptamer-based strategy, which was demonstrated for the selective detection of L. casei in commercial dairy drinks, with a dynamic range of 10 5 to 10 9 cfu/mL. Viable and nonviable L. casei cells could be discriminated based on the significant difference in fluorescence intensity. This established strategy is of high selectivity and sensitivity, and can be used for rapid analysis of viable L. casei in quality control and food surveillance areas., (Copyright © 2019 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

To validate survival of Lactobacillus casei strain Shirota (LcS) during passage through the gastrointestinal tract of healthy Singaporean young adults, 21 participants (18-25 years old) were asked to consume a 100 ml of fermented milk drink containing 1.0×10 8 cfu/ml of LcS daily for 14 days, and to maintain their dietary habit and life style. During and at the end of the ingestion period, both culture method (identity confirmed by ELISA) and 16s rRNA sequencing results revealed that viable LcS (7.27 and 7.64 log 10 cfu/g of faeces at the ingestion period Day 7 and Day 14, respectively) and Lactobacillus could be recovered from the faeces of all the subjects. The viable LcS count from male and female were comparable for each time point. Before consumption (baseline) and 14 days after cessation of consumption of the fermented milk, LcS was not detected in most of the subjects. In this study condition, the composition of the major gut microbiota (>0.1% in relative abundance of genus) and characteristics of defaecation such as stool consistency and frequency of defecation did not change throughout the study before and after ingestion of LcS. LcS was able to survive passage through the gastrointestinal tract of Singapore adults without sustainable colonisation, but the effect of LcS on microbiota modulation, stool consistency and frequency was not observed under this study condition.

Psychobiotics are probiotic microorganisms that may exert positive influence on the psychological status of the host. Studies have revealed immunological and microbiological correlations of gut microbiota and the gut-brain axis, and have investigated psychobiotics based on the findings of the gut-brain axis. Considering their mode of actions, the present study sets anti-inflammatory effect, neurotransmitter modulation, and gut microbiota modulation as three essential criteria to evaluate Lactobacillus casei ATG-F1 (F1), L. reuteri ATG-F3 (F3), and L. reuteri ATG-F4 (F4) isolated from newborns as psychobiotics candidates in a healthy mouse model and compares the results with a non-treated control group and an ampicillin-induced gut dysbiosis (Amp) group as a negative control. The F3 and F4 strains showed anti-inflammatory effects in vitro in RAW264.7 murine macrophages, and the level of anti-inflammatory cytokine interleukin (IL)-10 increased in ileums of mice orally administered with the F4 strain. Serum dopamine level significantly increased only in the F4-treated group as compared with the control group. Serum serotonin level was unaffected in Lactobacillus -treated groups, while a significant decrease in serum serotonin level was observed in the Amp group. Bacteroidetes population increased in fecal samples of the F4-treated group as compared with the control, and Bacteroidales S24-7 and Prevotellaceae population significantly increased at family level in fecal samples from the F4-treated group as compared with the control. In contrast, the Amp group showed an increase in the level of Proteobacteria and a decrease in the level of Bacteroidetes as compared with the control group. Transcriptome analysis revealed a distinctive clustering in ileums from the F4-treated group as compared to other experimental groups. In addition, the circadian rhythm pathway showed maximum enrichment in ileums of Lactobacillus -treated mice, and the F4-treated group showed the highest fold changes in circadian rhythm-related genes ( Dbp, Per1, Per2 , and Per3 ). Conclusively, L. reuteri ATG-F4 is suggested as a potential psychobiotics through demonstrations of anti-inflammatory effects, serum dopamine modulation, and gut microbiota modulation in a healthy murine model in the present study. Moreover, we carefully suggest gut circadian rhythm modulation as another important criterion of psychobiotics, which may have an important role in the gut-brain axis.

The objective of this study was to evaluate the probiotic properties of Lactobacillus casei and Lactobacillus fermentum strains, as well as to select novel and safe strains for future development of functional fermented products. The in vitro auto-aggregation, co-aggregation, hydrophobicity, β-galactosidase production, survival to gastrointestinal tract (GIT), and antibiotic susceptibility were evaluated. The selected strains were additionally tested by the presence of genes encoding adhesion, aggregation and colonization, virulence factors, antibiotic resistance, and biogenic amine production, followed by the evaluation of acidifying kinetic parameters in milk, and survival of the strains under simulated GIT conditions during refrigerated storage of fermented milk. Most strains of both species showed high auto-aggregation; some strains showed co-aggregation ability with other lactic acid bacteria (LAB) and/or pathogens, and both species showed low hydrophobicity values. Seven L. casei and six L. fermentum strains produced β-galactosidase enzymes, and ten strains survived well the simulation of the GIT stressful conditions evaluated in vitro. All strains were resistant to vancomycin, and almost all the strains were resistant to kanamycin. L. casei SJRP38 and L. fermentum SJRP43 were distinguished among the other LAB strains by their higher probiotic potential. L. fermentum SJRP43 presented fewer genes related to virulence factors and antibiotic resistance and needed more time to reach the maximum acidification rate (V max ). The other kinetic parameters were similar. Both strains survived well (> 8 log 10 CFU/mL) to the GIT-simulated conditions when incorporated in fermented milk. Therefore, these strains presented promising properties for further applications in fermented functional products.

The use of selected autochthonous mesophilic lactic acid bacteria as starter cultures was investigated according to the traditional protocol for making Pecorino Crotonose (PC). Leuconostoc mesenteroides subsp. mesenteroides 2A, Lactobacillus casei 23C and Lactobacillus plantarum 18C (Autochthonous Starter, AS1) and Leuc. mesenteroides subsp. mesenteroides 2A, and L. casei 25D and 16A (AS2) were isolated and identified from aged ewes' milk PC cheeses, selected based on several enzymatic activities, and used as starter cultures. As shown by the in vitro kinetic of acidification, selected starter cultures had suitable capabilities to acidify. The manufacture of PC cheeses was carried out at an industrial plant scale. A control cheese (CC) was also made, using commercial starters consisting of mesophilic and thermophilic species. Ripening lasted 105 days at 10 °C. A poly-phasic approach was used to compare cheeses during manufacture and ripening, mainly based on pyrosequencing of the 16S rRNA targeting DNA, proteolysis and volatile component analyses. Compared to CC, both autochthonous starter cultures slightly affected the gross chemical composition of PC cheese. The cell density of thermophilic starters of CC progressively decreased throughout ripening. Plate count and RAPD-PCR showed that the cell number of autochthonous lactobacilli cultures of PC cheeses, made with AS1 and AS2, was almost constant throughout ripening and abundantly higher than that observed in CC. As shown by culture-independent analysis, the OTUs found during ripening varied depending on the manufacture with or without autochthonous starter cultures. The major chemical differences among cheeses were the concentration of free amino acids and the synthesis of some key volatile components (e.g., 2-methyl-1-propanol, 2-methyl-1-butanol, isobutyric, isovaleric, and isocaproic acids). Compared to CC, the use of AS1 positively affected the overall cheese quality., (Copyright © 2018. Published by Elsevier Ltd.)

Bacterial membrane vesicles have been implicated in a broad range of functions in microbial communities from pathogenesis to gene transfer. Though first thought to be a phenomenon associated with Gram-negative bacteria, vesicle production in Staphylococcus aureus, Lactobacillus plantarum, and other Gram-positives has recently been described. Given that many Lactobacillus species are Generally Regarded as Safe and often employed as probiotics, the engineering of Lactobacillus membrane vesicles presents a new avenue for the development of therapeutics and vaccines. Here we characterize and compare the membrane vesicles (MVs) from three different Lactobacillus species (L. acidophilus ATCC 53544, L. casei ATCC 393, and L. reuteri ATCC 23272), with the aim of developing future strategies for vesicle engineering. We characterize the vesicles from each Lactobacillus species comparing the physiochemical properties and protein composition of each. More than 80 protein components from Lactobacillus-derived MVs were identified, including some that were enriched in the vesicles themselves suggesting vesicles as a vehicle for antimicrobial delivery. Additionally, for each species vesicular proteins were categorized based on biological pathway and examined for subcellular localization signals in an effort to identify possible sorting mechanisms for MV proteins.

Background and Objective: Coconut flour is known to be highly nutritious flour and contains high dietary fiber. The aim of this study was to make "bio-yoghurt beverage grafted with coconut flour and containing probiotic bacteria which is recommended as a functional milk product., Materials and Methods: Chemical, phytochemical studies and antimicrobial activity have been performed on coconut flour which was used to make the beverage. Bio-yoghurt beverages made with different ratios of coconut flour (0, 2, 4 and 6%) were chemical, microbiological and sensory tested when fresh and during storage for 15 days of cold storage., Results: Chemical composition of coconut flour showed reasonable contents of moisture, ash, fat, fatty acids, protein, crude fiber, total solids, total phenols and antioxidants. Coconut flour showed antibacterial activity against some foodborne pathogenic bacteria. The addition of coconut flour to make bio-yoghurt beverages increased its contents of total solids, protein, ash, fiber, acidity, antioxidant activity, total phenols, improved yoghurt sensory and rheological properties especially when probiotic bacteria were used. The results did not reveal any significant differences (p>0.05), between the bacterial counts of yoghurt starter culture, Lactobacillus rhamnosus, Lactobacillus casei in yoghurt control (without coconut) and bio-yoghurt treatments (with coconut), during cold storage. Moulds and yeasts were not detected in all bio-yoghurt treatments; meanwhile they appeared in yoghurt control after 15 days indicating coconut antifungal activity and subsequently a period of time to save more for this drink. All bio-yoghurt beverages with different ratios of coconut flour were sensory accepted and showed more favorable properties, particularly for the viscosity., Conclusion: A new functional dairy product of bio-yoghurt beverage contain coconut flour high fiber content was prepared with probiotic bacteria and showed good chemical, microbiological and sensory/rheological properties.

Objective: Monitoring selected key species related to health or disease may facilitate caries risk assessment and discovery of novel ecological preventive and therapeutic approaches. This study aimed at quantifying Actinomyces naeslundii, Bifidobacterium spp., Lactobacillus acidophilus, Lactobacillus casei group, Streptococcus gordonii, Mitis group and Streptococcus mutans by quantitative polymerase chain reaction (qPCR) in dental biofilm from Brazilian children with different stages of early childhood caries (ECC)., Design: Seventy-five preschool children were clinically evaluated by ICDAS criteria and divided into groups: caries-free (CF; n = 20), enamel caries lesions (ECL; n = 17) and dentine caries lesions (DCL; n = 38). Plaque samples from all children were collected for detection and quantification of the selected bacteria., Results: L. acidophilus and L. casei group were absent in almost all plaque samples. No differences in relative proportions of A. naeslundii, Mitis group and S. gordonii were observed in any stage of caries. However, S. mutans and Bifidobacterium spp. were present at higher concentrations in the biofilm of children with DCL (p < 0.001). Multivariate analysis showed that S. mutans and Bifidobacterium spp. were strongly associated with biofilm in children with DCL., Conclusion: Differences were observed in the proportion of acidogenic and aciduric bacteria with dental caries progression. The data indicate that S. mutans and Bifidobacterium spp. in dental biofilm may be involved in some progression processes for ECC., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Bacteria in Lactobacillus casei group, including Lactobacillus casei (L. casei), Lactobacillus paracasei (L. paracasei), and Lactobacillus rhamnosus (L. rhamnosus) are important lactic acid bacteria in the production of fermented dairy products and are faced with the controversial nomenclatural status due to their close phylogenetic similarity. To probe the evolution and phylogeny of L. casei group, 100 isolates of lactic acid bacteria originated from naturally fermented dairy products in Tibet of China were subjected to multilocus sequence typing (MLST). The MLST scheme, based on analysis of the housekeeping genes fusA, ileS, lepA, leuS, pyrG, recA and recG, revealed that all the isolates belonged to a group containing the L. paracasei reference strains and were clearly different from the strains of L. casei and L. rhamnosus. Although nucleotide diversity (π) was low for the seven genes (ranging from 0.00341 for fusA to 0.01307 for recG), high genetic diversity represented by 83 sequence types (STs) with a discriminatory index of 0.98 was detected. A network-like structure based on split decomposition analysis, and the high values of the relative effect of recombination and mutation in the diversification of the lineages (r/m = 4.76) and the relative frequency of occurrence of recombination and mutation (ρ/θ = 2.62) indicated that intra-species recombination occurred frequently and homologous recombination played a key role in generating genotypic diversity amongst L. paracasei strains in Tibet. The discovery of 51 new STs and the results of STRUCTURE analysis suggested that the L. casei group in Tibet had an individual and particular population structure in comparison to European isolates. Overall, this research might be the first report about genetic diversity and population structure of Lactobacillus populations isolated from naturally fermented dairy products in Tibet based on MLST scheme.

In the present study we investigated the pro-inflammatory and anti-inflammatory effect of Lactobacillus casei following infection with multi-drug resistant enteropathogenic Escherichia coli infection in experimental rabbits. For this purpose, 40 adult rabbits were divided into different groups and were infected with multi-drug resistant E. coli AZ1 strain except the control groups. The rabbits were orally administered with L. casei SABA6 strain in two different ways i.e. pre-treatment and post-treatment and both were continued for 7 days. The rabbits were sacrificed sequentially at 0, 4, 7 and 10 days post infection (dpi). Serum and intestinal tissue samples were collected from each rabbit. Intestinal tissue samples were subjected to histopathological examination that showed microscopic lesions at 4 and 7 dpi among infected group. The serum samples were processed for determination of Interleukin-6 (IL-6, pro-inflammatory) and Interleukin-10 (IL-10, anti-inflammatory) using ELISA. It was found that oral administration of L. casei SABA6 reduces the eruption of intestinal epithelial cells and reduces the incidence of diarrhea. Further, L. casei SABA6 also resulted in immuno modulation by significant increase in concentration of IL-6 and IL-10 particularly at 4 and 7 dpi and protects against E. coli AZ1 infection. Altogether, it was concluded that increased IL-6 and IL-10 levels were responsible for protection against EPEC infections. The sequential sacrifice of experimental animals could be adopted for future studies to find out pathogenesis and virulence mechanism of EPEC infections along with protective efficacy of different probiotics.

To investigate the effects of inoculants and environmental temperature on fermentation quality and bacterial diversity of alfalfa silage, first-cut alfalfa was ensiled with or without two screened lactic acid bacteria (LAB) strains, Lactobacillus plantarum, LP, and Lactobacillus casei, LC. Each treatment was divided into three parts and stored at 20°C, 30°C, 40°C, respectively. After 60 days ensiling, fermentation characteristics were measured and bacterial diversity was investigated by 16S ribosomal RNA gene sequencing using Illumina MiSeq platform. LP and LC decreased pH, coliform bacteria counts and increased lactic acid content at 20°C, and the two strains decreased pH, ammonia-N concentration, coliform bacteria counts at 30°C. When the environmental temperature was 40°C, silage treated with LC showed lower LAB and coliform bacteria counts and higher lactic acid content than the untreated and LP treated silages. Butyric acid mainly appeared in silages stored at 40°C. The relative abundance of Lactobacillus in alfalfa silages stored at 20°C and 30°C was highest and increased after LP and LC were added. Garciella was another dominant genus in silages stored at 40°C. In conclusion, LP and LC improved fermentation quality of alfalfa silage by increasing Lactobacillus proportions at 20°C and 30°C; ensiling alfalfa at 40°C was difficult because of Garciella., (© 2018 Japanese Society of Animal Science.)

Two Gram-stain-positive, rod-shaped, non-motile, catalase-negative and facultative anaerobic strains, NCYUAS T and BCRC 18859 (=NRIC 1947), were isolated from cow manure of Taiwan and coconut juice of Philippines, respectively. Comparative sequence analysis of 16S rRNA gene revealed that the novel strains were members of the genus Lactobacillus. These two strains had 100% of 16S rRNA gene sequence similarity and 98.6% of average nucleotide identity (ANI) value based on whole genome sequences. On the basis of 16S rRNA gene sequence similarity, the type strains of Lactobacillus casei (99.6% similarity), Lactobacillus paracasei subsp. paracasei (99.1%), L. paracasei subsp. tolerans (99.1%), Lactobacillus rhmnosus (99.0%) and 'Lactobacillus zeae' (99.7%) were the closest neighbors to these novel strains. The results of phenotypic and chemotaxonomic characterization, multilocus sequence analysis (MLSA) based on the sequences of three housekeeping genes (dnaK, pheS and yycH), whole-genome sequence (WGS)-based comparison by ANI and in silico DNA-DNA hybridization (isDDH), species-specific PCR and whole-cell MALDI-TOF MS spectral pattern analyses demonstrated that the novel two strains represented a single, novel species within the L. casei group, for which the name Lactobacillus chiayiensis sp. nov., is proposed. The type strain is NCYUAS T (=BCRC 81062 T =NBRC 112906 T )., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Lactic acid bacteria have been categorized as probiotics and play a crucial role in human health by stimulating the supply of nutrients, shaping the immune system, and preventing the colonization of pathogenic microbes. This study investigated the mechanisms for the action of three potential probiotic Lactobacillus strains: Lactobacillus casei SR1, Lactobacillus casei SR2, and Lactobacillus paracasei SR4 isolated from human breast milk. These Lactobacillus strains were identified via 16S DNA sequencing and characterized via biochemical assays including acid resistance, bile resistance, antioxidant activity, and antibiotic susceptibility. The bioactivity of the cell-free culture supernatant (CFCS) secreted by these strains on the cervix cancer (HeLa) cell line was also evaluated via cytotoxicity assay and apoptosis analysis. The mechanism of anticancer activity was also investigated via RT-qPCR and western blotting. The results demonstrated that these newly isolated Lactobacillus strains from human milk displayed noticeable probiotic characteristics such as excellent antibiotic susceptibility, outstanding antioxidant activity, and promising resistance to low pH and high concentration of bile salts. The results of the conducted bioactivity assays verified that the CFCSs had acceptable anticancer effects on cervix cancer (HeLa) cells by upregulating the expression of apoptotic genes BAX, BAD, caspase3, caspase8, and caspase9 and by downregulating the expression of the BCl-2 gene. Overall, these results indicate that the Lactobacillus strains isolated from human breast milk could be considered as a topical medication with a potential therapeutic index due to their efficacy against cervix cancer cells.

The bacterial diversity and community structure involved in Chinese sauerkraut is one of the most important factors shaping the final characteristics of traditional foods. In this research, Lactobacillus casei 11MZ-5-1 was applied in Chinese sauerkraut fermentation as a starter culture. Illumina Miseq sequencing analysis was used to reveal the bacterial diversity and community structure during Chinese sauerkraut fermentation. A total of 177 283 high-quality reads of 16S rRNA V4 regions were obtained. The inoculation of L. casei 11MZ-5-1 decreased considerably the bacterial richness and bacterial diversity. This inoculum led to the replacement of Lactococcus by Lactobacillus. The levels of Pseudomonas and Enterobacter bacteria decreased. These findings reveal the evolution of important bacterial groups that are involved in fermentation and will facilitate improvements in the Chinese sauerkraut fermentation process., Significance and Impact of the Study: This research thoroughly revealed the effects of Lactobacillus casei 11MZ-5-1 starter cultures on bacterial communities during Chinese sauerkraut fermentation. Illumina Miseq sequencing was effective technique to monitor the bacterial diversity and community structure. The inoculation of L. casei 11MZ-5-1 led to the decline of bacterial richness and diversity together with a consistent predominance of Lactobacillus during spontaneous fermentation. The result collectively suggested L. casei 11MZ-5-1 is a promising starter in Chinese sauerkraut manufacturing., (© 2017 The Society for Applied Microbiology.)

Background & Objectives: Despite advancements in molecular-based methods, the composition of the human ileal microbiota and the effects of synbiotics/probiotics on its microbes remain poorly understood. The aim of this study was to determine the composition of the mucus microbiota in the human ileum and to assess the effects of oral administration of synbiotics on the microbiota., Methods: As part of a clinical trial for synbiotics treatment and surgical infection, ileal mucus was sampled when resection of the ileocecal portion was required. The microbiota composition was examined using 16S rRNA-targeted real-time-quantitative polymerase chain reaction., Results: A total of 33 samples from the synbiotics group and 39 from the control group were analyzed. Total numbers of bacteria in the ileum were 10 8.5 cells/g in the synbiotics group and 10 8.4 cells/g in the control group, in which obligate anaerobes were dominant over facultative anaerobes. The level of Enterobacteriaceae was significantly lower in the synbiotics group than in the control group. The administered probiotics species Lactobacillus casei strain Shirota and Bifidobacterium breve strain Yakult were detected in 42 and 76 per cent of the synbiotics group, respectively. No significant correlations were observed between tumour stage/size and the various microbes present, except for a negative correlation between tumour size and Bifidobacterium., Interpretation & Conclusions: The present analysis of a substantial number of samples from surgically resected intestines showed an abundance of obligate anaerobes as a characteristic feature of the ileal mucus microbiota. Our results also indicated that the synbiotics intervention induced a prominent reduction in Enterobacteriaceae in the ileal microbiota., Competing Interests: S. Komatsu, E. Sakamoto and M. Nagino have no conflict of interest to declare. T. Asahara and K. Nomoto are researchers of Yakult Honsha Co., Ltd, Japan.

Long ripened cheeses, such as Grana Padano (GP), a Protected Designation of Origin (PDO) Italian cheese, harbor a viable microbiota mainly composed of non-starter lactic acid bacteria (NSLAB), which contribute to the final characteristics of cheese. The NSLAB species Lactobacillus rhamnosus, Lb. casei and Lb. paracasei are frequently found in GP, and form a closely related taxonomic group (Lb. casei group), making it difficult to distinguish the three species through 16S rRNA sequencing. SpxB, a metabolic gene coding for pyruvate oxidase in Lb. casei group, was recently used to distinguish the species within this bacterial group, both in pure cultures and in cheese, where it could provide an alternative energy source through the conversion of pyruvate to acetate. The aim of this work was to study the evolution of the metabolically active microbiota during different stages of GP ripening, targeting 16S rRNA to describe the whole microbiota composition, and spxB gene to monitor the biodiversity within the Lb. casei group. Furthermore, activation of pyruvate oxidase pathway was measured directly in cheese by reverse transcription real time PCR (RT-qPCR). The results showed that Lb. casei group dominates throughout the ripening and high-throughput sequencing of spxB allowed to identify four clusters inside the Lb. casei group. The dynamics of the sequence types forming the clusters were followed during ripening. Pyruvate oxidase pathway was expressed in cheese, showing a decreasing trend over ripening time. This work highlights how the composition of the microbiota in the early manufacturing stages influences the microbial dynamics throughout ripening, and how targeting of a metabolic gene can provide an insight into the activity of strains relevant for dairy products., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Lactobacillus casei,Lactobacillus paracasei and Lactobacillusrhamnosus form a closely related taxonomic group (the L. casei group) within the facultatively heterofermentative lactobacilli. Strains of these species have been used for a long time as probiotics in a wide range of products, and they represent the dominant species of nonstarter lactic acid bacteria in ripened cheeses, where they contribute to flavour development. The close genetic relationship among those species, as well as the similarity of biochemical properties of the strains, hinders the development of an adequate selective method to identify these bacteria. Despite this being a hot topic, as demonstrated by the large amount of literature about it, the results of different proposed identification methods are often ambiguous and unsatisfactory. The aim of this study was to develop a more robust species-specific identification assay for differentiating the species of the L. casei group. A taxonomy-driven comparative genomic analysis was carried out to select the potential target genes whose similarity could better reflect genome-wide diversity. The gene mutL appeared to be the most promising one and, therefore, a novel species-specific multiplex PCR assay was developed to rapidly and effectively distinguish L. casei, L. paracasei and L. rhamnosus strains. The analysis of a collection of 76 wild dairy isolates, previously identified as members of the L. casei group combining the results of multiple approaches, revealed that the novel designed primers, especially in combination with already existing ones, were able to improve the discrimination power at the species level and reveal previously undiscovered intraspecific biodiversity.

The purpose of this work was to study the potential of gas chromatography-ion mobility spectrometry (GC-IMS) to differentiate lactic acid bacteria (LAB) through target identification and fingerprints of volatile metabolites. The LAB selected were used as reference strains for their influence in the flavour of cheese. The four strains of LAB can be distinguished by the fingerprints generated by the volatile organic compounds (VOCs) emitted. 2-butanone, 2-pentanone, 2-heptanone and 3-methyl-1-butanol were identified as relevant VOCs for Lactobacillus casei and Lactobacillus paracasei subsp. paracasei. 2-Butanone and 3-methyl-1-butanol were identified in Lactococcus lactis subsp. lactis and Lactococcus cremoris subsp. cremoris. The IMS signals monitoring during a 24-30h period showed the growth of the LAB in vitro. The results demonstrated that GC-IMS is a useful technology for bacteria recognition and also for screening the aromatic potential of new isolates of LAB., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A laboratory-built high-sensitivity flow cytometer (HSFCM) was employed for the rapid and accurate detection of lactic acid bacteria (LAB) and their viability in probiotic products. LAB were stained with both the cell membrane-permeable SYTO 9 green-fluorescent nucleic acid stain and the red-fluorescent nucleic acid stain, propidium iodide, which penetrates only bacteria with compromised membranes. The side scatter and dual-color fluorescence signals of single bacteria were detected simultaneously by the HSFCM. Ultra-high temperature processing milk and skim milk spiked with Lactobacillus casei were used as the model systems for the optimization of sample pretreatment and staining. The viable LAB counts measured by the HSFCM were in good agreement with those of the plate count method, and the measured ratios between the live and dead LAB matched well with the theoretical ratios. The established method was successfully applied to the rapid quantification of live/dead LAB in yogurts and fermented milk beverages of different brands. Moreover, the concentration and viability status of LAB in ambient yogurt, a relatively new yet popular milk product in China, are also reported.

To demonstrate the gastrointestinal survival of Lactobacillus casei strain Shirota (LcS) in healthy Vietnamese adults, a fermented milk drink containing LcS was administered daily for 14 days. Twenty-six healthy Vietnamese adults took part in the study. Each participant consumed 65 mL of a fermented milk drink containing LcS daily for 14 days. The drink contained a dose of 10 8 CFU/mL LcS. Fecal samples were collected before, during and after consuming the fermented milk drink. LcS was confirmed by culture and ELISA. After 7 and 14 days of ingesting fermented milk drink, LcS was recovered from fecal samples at average of 5.0×10 7 CFU/g feces (n=26) and 5.4×10 7 CFU/g feces (n=26), respectively. LcS persisted in 8 voluteers until day 42 (after 14 days stopping fermented milk drink) at 0.0033×10 7 CFU/g feces (n=8). We confirmed survival of LcS after passage through the gastrointestinal tract of Vietnamese adults.

The antidiabetic effects of Lactobacillus. paracasei subsp. paracasei G15 and Lactobacillus. casei Q14 in high fat diet and streptozotocin-induced type 2 diabetic (T2D) rats were evaluated in this study. The strains were separated from Chinese traditional fermented dairy food. Administration of G15 and Q14 for 6 weeks significantly improved the glucose tolerance and reduced the HbA1c levels in T2D rats. The probiotic treatment reduced the intestinal mucosal permeability and improved the epithelial barrier function through modification of the gut microbiota, which in turn lowered circulating LPS and inflammation cytokines, including IL-1β and IL-8, and eventually alleviated the inflammatory status and islet β-cell dysfunction. Combination of Q14 and metformin reversed the thymic atrophy and both G15 and Q14 lowered the circulating IL-6 level, indicating the immune-modulating potential of the strains. Lactobacillus. paracasei subsp. paracasei G15 and Lactobacillus. casei Q14 provide an insight into the biotherapy application of traditional fermented foods and their functional ingredients in the treatment of diabetes.

Oral infections such as periodontitis and tooth decay are the most common diseases of humankind. Oleoresins from different copaifera species display antimicrobial and anti-inflammatory activities. Copaifera reticulata is the commonest tree of this genus and grows abundantly in several Brazilian states, such as Pará, Amazonas, and Ceará. The present study has evaluated the chemical composition and antimicrobial potential of the Copaifera reticulata oleoresin (CRO) against the causative agents of tooth decay and periodontitis and has assessed the CRO cytotoxic potential. Cutting edge analytical techniques (GC-MS and LC-MS) aided the chemical characterization of CRO. Antimicrobial assays included determination of the Minimum Inhibitory Concentration (MIC), determination of the Minimum Bactericidal Concentration (MBC), determination of the Minimum Inhibitory Concentration of Biofilm (MICB50), Time Kill Assay, and Checkerboard Dilution. Conduction of XTT assays on human lung fibroblasts (GM07492-A cells) helped to examine the CRO cytotoxic potential. Chromatographic analyses revealed that the major constituents of CRO were β-bisabolene, trans-α-bergamotene, β-selinene, α-selinene, and the terpene acids ent-agathic-15-methyl ester, ent-copalic acid, and ent-polyalthic acid. MIC and MBC results ranged from 6.25 to 200 μg/mL against the tested bacteria. The time-kill assay conducted with CRO at concentrations between 50 and 100 μg/mL showed bactericidal activity against Fusobacterium nucleatum (ATCC 25586) and Streptococcus mitis (ATCC 49456) after 4 h, Prevotella nigrescens (ATCC 33563) after 6 h, Porphyromonas gingivalis (ATCC 33277) and Lactobacillus casei (clinical isolate) after 12 h, and Streptococcus salivarius (ATCC 25975) and Streptococcus mutans (ATCC 25175) after 18 h. The fractional inhibitory concentration indexes (FICIs) revealed antagonistic interaction for Lactobacillus casei (clinical isolate), indifferent effect for Porphyromonas gingivalis (ATCC 33277), Fusobacterium nucleatum (ATCC 25586), Prevotella nigrescens (ATCC 33563), and Streptococcus salivarius (ATCC 25975), and additive effect for Streptococcus mutans (ATCC 25175) and Streptococcus mitis (ATCC 49456). Treatment of GM07492-A cells with CRO demonstrated that concentrations up to 39 μg/mL significantly reduced cell viability as compared to the negative control, being IC50 equal to 51.85 ± 5.4 μg/mL. These results indicated that CRO plays an important part in the search for novel sources of agents that can act against oral pathogens., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A selective culture medium containing acid-hydrolyzed gliadins as the sole nitrogen source was used in the search for sourdough-indigenous lactic acid bacteria (LAB) with gliadin-metabolizing activity. Twenty gliadin-degrading LAB strains were isolated from 10 sourdoughs made in different ways and from different geographical regions. Fifteen of the 20 isolated strains were identified as Lactobacillus casei, a species usually reported as subdominant in sourdough populations. The other 5 gliadin-degrading strains belonged to the more commonly encountered sourdough species Leuconostoc mesenteroides and Lactobacillus plantarum. All these strains were shown to be safe in terms of their resistance to antimicrobial agents. When individually incubated with the α2-gliadin-derived immunotoxic 33-mer peptide (97.5 ppm), half of the L. casei strains metabolized at least 50% of it within 24 h. One strain metabolized 82% of the 33-mer peptide within 8 h and made it fully disappear within 12 h. These results reveal for the first time the presence in sourdough of proteolytic L. casei strains with the capacity to individually metabolize the coeliac-disease-related 33-mer peptide.

Aim of the present study was to characterise and evaluate probiotic potential of lactobacilli isolated from indigenous poultry. Lactobacilli were isolated from poultry droppings and identified by genus specific polymerase chain reaction and 16S rRNA gene sequencing. Isolates were characterised in vitro by their ability to tolerate low pH and bile salts, phytase activity, antimicrobial activity, antibiotic susceptibility profile, and autoaggregation and coaggregation with poultry gut pathogens. In vivo evaluation of selected isolates was done by their effect on the body weight gain and immune response of broiler chicks. Total of 90, one-day old chicks, were randomly divided in 9 groups and given selected lactobacilli alone and in combinations (10 8 cfu/bird, daily) from day 7 to day 35. Body weight gain and humoral immune response to New Castle Disease Virus (NDV) vaccine were determined weekly. Three lactobacilli isolates (SMP52, SMP64 and SMP70) were selected as potentially probiotic bacteria on the basis of in vitro characterisation and identified as Lactobacillus crispatus, Lactobacillus casei and L. crispatus, respectively. Chicks supplemented with 'SMP52', 'SMP64', 'SMP70' and 'SMP64+SMP70' and a commercial probiotic product (Protexin) showed significantly higher mean weight gain per bird (1,584±35.2, 1,629±30.6, 1,668±34.7, 1,619±29.5 and 1,576±31.7 g/bird, respectively) as compared to negative control group (1,394±26.7 g/bird), on day 35. SMP 70 also showed significantly higher geometric mean titre against NDV vaccine at day 21 as compared to negative control. It is concluded that L. crispatus SMP52, L. casei SMP64 and L. crispatus SMP70 are potential probiotic candidates which alone or in different combinations may increase body weight of broilers.

Background: Gut microbiota has a significant role in the pathogenesis of diabetes. Colonic microflora modulation using an antibiotic might have an emerging role to treat the metabolic disorders. The present study was aimed to optimize the Moxifloxacin loaded chitosan microspheres (MCMs) by emulsion cross linking method for colon targeted delivery to alter the microflora., Methods: Preliminary optimization of MCMs was carried out using Placket-Burman design (PBD) following by final optimization with Box-Behnken design (BBD). Optimized MCMs were evaluated for yield, particle size, entrapment efficiency and in vitro/ in vivo antimicrobial activities., Results: FTIR spectroscopy of MCMs confirms the absence of chemical interactions during the formulation. MCMs were found to be smooth, spherical with particle size around 20μm. An enteric coating of MCMs prevented the drug release in the acidic environment of the stomach and ileum with complete release at the colon. MCMs had followed the korsmeyer - peppas model of drug release, indicating the drug release by non-fickian diffusion pattern. MCMs showed significant in vitro antimicrobial activity against Lactobacillus casei and Escherichia coli. In vivo results of MCMs exhibited prolonged antimicrobial effect of drug in the cecal content of rats. Significant protective activity observed in the ileum and colon histology in rats treated with MCMs compared to the pure drug., Conclusion: MCMs were formulated by emulsion cross linking method using QBD approach. An enteric coating around the microspheres prevented the premature drug release at upper gastrointestinal tract, while chitosan cross linking has provided the sustain release of the drug in the colonic region over the time.

Identifying Lactobacillus casei and its closely related taxa at the species and strain level using only phenotypic and genotypic (16S rDNA sequence homology analysis) techniques often yields inaccurate results. In this study, the dnaJ chaperone gene was investigated as a molecular target for inter- and intraspecies discrimination within the Lb. casei group as well as for the development of specific primers for species identification. The results showed that most of the examined strains could be clearly distinguished from closely related species based on the sequenced fragments. At the interspecies level, the dnaJ sequence similarities were 81.7%-85.5%. However, at the intraspecies level, the dnaJ sequence similarities were 96.2-100% and could be assigned to different haplotypes in Lactobacillus paracasei and Lactobacillus rhamnosus, respectively. Compared to the 16S rRNA gene, the dnaJ sequence showed greater variation at both the species and strain level. Thus, the dnaJ gene can be proposed as an alternative marker for the Lb. casei group that provides higher discriminatory power than the 16S rRNA gene. In addition, species-specific primers were developed and subsequently employed in two-plex minisequencing analysis and shown to be specific for Lb. paracasei and Lb. rhamnosus. Our data indicate that phylogenetic relationships in the Lb. casei group can be resolved using comparative sequence analysis of the dnaJ gene and that the Lb. paracasei and Lb. rhamnosus species can be simultaneously identified using a novel species-specific minisequencing assay., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Free radicals are connected with the increased risk of certain diseases, especially cancers. There is some scientific evidence that antioxidant-rich diet may inhibit the negative impact of free radicals. The aim of the present study was to analyse the antioxidant capacity of the selected commercial natural and flavoured fermented milks offered in Poland, derived from different producers., Methods: The following commercially available natural fermented milks: 12 yoghurts, 12 kefirs, 2 butter milks, 2 cultured milks, Turkish yoghurt drink (ayran) and the following flavoured fermented milks: 22 yoghurts, 2 acidophillus milks, 2 kefirs, butter milk and vegetable flavoured fermented milk were analysed for their antioxidant potential. The antioxidant capacity was assessed, in two replicates and twice for each product, by means of ferric reducing antioxidant power (FRAP) and DPPH radical scavenging ability (expressed as ARP - anti radical power) methods., Results: Among all analysed plain products, yoghurts and kefirs were characterised by the highest antioxidant activity. The presence of probiotic Lactobacillus casei strains in the product positively affected both FRAP and ARP values. Antioxidant capacity of the flavoured fermented milks was primarily affected by the type and quality (e.g. fruit concentration) of the added flavouring preparation. The most valuable regarding the estimated parameters were chocolate, coffee, grapefruit with green tea extract as well as bilberry, forest fruits, strawberry and cherry with blackcurrant fillings., Conclusions: Protein content, inclusion of probiotic microflora as well as type and quality of flavouring preparations are the main factors affecting antioxidant properties of fermented milks.

Background: Goat milk production in Shaanxi province is dominant in China, but the product is mainly infant formula and adult milk powder; product homogeneity is serious and has no goat yoghurt with probiotic culture., Methods: The effect of bacteria proportion (1:3:1, 1:2:1, 1:1:1, 2:1:1, 3:1:1) on pH, acidity, and viable counts and sensory evaluation of goat milk fermented by probiotics including L. acidophilus, B. bifidum  or L. casei besides, S. thermophilus and L. bulgaricus for developing AB-goat yoghurt and BC-goat yoghurt was investigated., Results: The optimum bacteria proportion of L. acidophilus : B. bifidum : S. thermophilus and L. bulgaricus for AB-goat yoghurt and B. bifidum : L. casei : S. thermophilus and L. bulgaricus for BC-goat yoghurt were both 2:1:1. The pH, acidity, the viable counts of L. acidophilus and B. bifidum, the total viable counts were respectively 4.60, 7.73 (g/L), 3.50×107 cfu/mL, 3.40×107 cfu/mL and 2.30×109 cfu/mL in AB-goat yoghurt. The pH, acidity, the viable counts of B. bifidum and L. casei, the total viable counts were respectively  4.61, 8.16 (g/L), 7.60×107 cfu/mL, 5.60×107 cfu/mL and 2.04×109 cfu/mL in BC-goat yoghurt., Conclusions: The bacteria proportion had a significant effect on fermentation of AB- and BC-goat yoghurt, the results are beneficial for developing AB-goat yoghurt and BC-goat yoghurt.

Aim: To determine those organisms of the genus Candida associated with dental caries by investigating samples from active carious lesions. Within the genus Candida, the species Candida albicans and Candida dubliniensis are capable of forming chlamydospores and germ tubes. Until it became possible in 1995 to differentiate between the two species taxonomically, C. dubliniensis was falsely identified as C. albicans. Whilst the importance of C. albicans for rapidly progressing early childhood caries (ECC) has been recognised, so far there have been only reports about C. dubliniensis in connection with children/mothers who have been infected with HIV or already developed AIDS. In the present study, C. dubliniensis was for the first time isolated from plaque and carious dentine of a healthy five-year-old boy., Methods: As part of the investigation, a number of samples were collected from individual children affected by active dental caries. Amongst the samples, one in particular indicated that Candida species might be involved. The patient was a five-year-old boy with ECC of the primary dentition, scheduled for restorative treatment under general anaesthesia. Before treatment, a salivary, plaque (region of 54/55) and soft carious dentine sample from the tooth 51 was taken before extraction. The counts of yeasts, lactobacilli (LB) and mutans streptococci were determined in the samples., Results: The boy's dmft was 11, which was dominated by the d component. In the saliva of the boy, LB and mutans streptococci (MS) were detected. In plaque and carious dentine, MS and most interestingly C. dubliniensis were present. The yeasts were visualised in carious dentine by means of scanning electron micrographs., Conclusions: Plaque and carious dentine may be a further habitat of C. dubliniensis.

Background: The ability of lactobacilli to adhere to the surface of the intestine is an important functional characteristic which can largely determine the effective colonization of the intestinal tract by probiotics. The following study compares the adhesion efficiency of the twenty strains of Lactobacillus genus belonging to Casei group to the Caco-2 cells and gastrointestinal mucus., Methods: Twenty isolates of lactobacilli belonging to Casei group were tested. The ability of bacterial cells to adhere to mucus was examined using adhesion assay to gastrointestinal mucus. Obtained results were compared with adhesion efficiency to Caco-2 cells. Phylogenetic relationship between isolates was analysed by rep-PCR., Results: The results showed large differences in adhesion efficiency between strains, as well as differences in the efficiency of adhesion to the intestinal epithelial cells and mucus. Group similarity highlighted by a rep-PCR technique does not correspond with groups of similarity in terms of the characteristics of the ability to adhere to mucus or the epithelial cells of intestinal tract., Conclusions: Strains having a high adhesion efficiency to enterocytes do not always show a high adhesion efficiency to the mucus. This may indicate the presence of different and multiple factors responsible for adhesion efficiency of Lactobacillus group Casei strains to epithelial cells and mucus.

In August 2003, the 284-bed community hospital Pierre-Le Gardeur (PLGH) in Quebec experienced a major outbreak associated with the Clostridium difficile NAP1/027/BI strain. Augmented standard preventive measures (SPMs) were not able to control this outbreak. It was decided in February 2004 to give to every adult inpatient on antibiotics, without any exclusion, a probiotic (Bio-K+: Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2) within 12 hours of the antibiotic prescription. Augmented SPMs were continued. The use of the probiotic in addition to SPMs was associated with a marked reduction of C. difficile infection (CDI). During the 10 years of observation, 44 835 inpatients received Bio-K+, and the CDI rate at PLGH declined from 18.0 cases per 10,000 patient-days and remained at low mean levels of 2.3 cases per 10,000 patient-days. Additionally, 10-year data collected by the Ministry of Health in Quebec comparing the CDI rate between Quebec hospitals showed that CDI rates at PLGH were consistently and continuously lower compared with those at similar hospitals. Blood cultures were monitored at PLGH for Lactobacillus bacteremia through the 10 years' experience, and no Lactobacillus bacteremias were detected. Despite the limitation of an observational study, we concluded that the probiotic Bio-K+ was safe and effective in decreasing our primary CDI rate., (© The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

A specific probiotic formulation composed of Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+) has been marketed in North America since 1996. The strains and the commercial products have been evaluated for safety, identity, gastrointestinal survival, and stability throughout shelf life. The capacity of both the fermented beverages and the capsules to reduce incidences of antibiotic-associated diarrhea and Clostridium difficile infection (CDI) has been demonstrated in human clinical trials. Individual strains and the finished products have shown antimicrobial activity against C. difficile and toxin A/B neutralization capacity in vitro. The use of this specific probiotic formulation as part of a bundle of preventive measures to control CDI in healthcare settings is discussed., (© The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Outbreaks of food-borne disease associated with the consumption of fresh and minimally processed fruits and vegetables have increased dramatically over the last few years. Traditional chemical sanitizers are unable to completely eradicate or kill the microorganisms on fresh produce. These conditions have stimulated research to alternative methods for increasing food safety. The use of protective cultures, particularly lactic acid bacteria (LAB), has been proposed for minimally processed products. However, the application of bioprotective cultures has been limited at the industrial level. From this perspective, the main aims of this study were to select LAB from minimally processed fruits and vegetables to be used as biocontrol agents and then to evaluate the effects of the selected strains, alone or in combination with natural antimicrobials (2-(E)-hexenal/hexanal, 2-(E)-hexenal/citral for apples and thyme for lamb's lettuce), on the shelf-life and safety characteristics of minimally processed apples and lamb's lettuce. The results indicated that applying the Lactobacillus plantarum strains CIT3 and V7B3 to apples and lettuce, respectively, increased both the safety and shelf-life. Moreover, combining the selected strains with natural antimicrobials produced a further increase in the shelf-life of these products without detrimental effects on the organoleptic qualities., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Lactobacillus casei group (Lcs) consists of three phylogenetically closely related species (L. casei, L. paracasei, and L. rhamnosus), which are widely used in the dairy and probiotic industrial sectors. Strategies to easily and rapidly characterize Lcs are therefore of interest. To this aim, we developed a method according to a technique known as high resolution melting analysis (HRMa), which was applied to a 150 bp groEL gene fragment. The analysis was performed on 53 Lcs strains and 29 strains representatives of species that are commonly present in dairy and probiotic products and can be most probably co-isolated with Lcs strains. DNA amplification was obtained only from Lcs strains, demonstrating the specificity of the groEL primers designed in this study. The HRMa clustered Lcs strains in three groups that exactly corresponded to the species of the L. casei group. A following HRMa separated the 39 L. paracasei strains in two well distinct intraspecific groups, indicating the possible existence of at least two distinct genotypes inside the species. Nonetheless, the phenotypic characterization demonstrated that the genotypes do not correspond to the two L. paracasei subspecies, namely paracasei and tolerans. In conclusion, the melting curve analysis developed in this study is demonstrably a simple, labor-saving, and rapid strategy obtain the genotyping of a bacterial isolate and simultaneously potentially confirm its affiliation to the L. casei group of species. The application of this method to a larger collection of strains may validate the possibility to use the proposed HRMa protocol for the taxonomic discrimination of L. casei group of species. In general, this study suggests that HRMa can be a suitable technique for the genetic typization of Lactobacillus strains., (Copyright © 2015 Elsevier GmbH. All rights reserved.)

The correct identification and characterisation of bacteria is essential for several reasons: the classification of lactic acid bacteria (LAB) has changed significantly over the years, and it is important to distinguish and define them correctly, according to the current nomenclature, avoiding problems in the interpretation of literature, as well as mislabelling when probiotic are used in food products. In this study, species-specific PCR and HRM (high-resolution melting) analysis were developed to identify strains belonging to the Lactobacillus casei group and to classify them into L. casei, Lactobacillus paracasei and Lactobacillus rhamnosus. HRM analysis confirmed to be a potent, simple, fast and economic tool for microbial identification. In particular, 201 strains, collected from International collections and attributed to the L. casei group, were examined using these techniques and the results were compared with consolidated molecular methods, already published. Seven of the tested strains don't belong to the L. casei group. Among the remaining 194 strains, 6 showed inconsistent results, leaving identification undetermined. All the applied techniques were congruent for the identification of the vast majority of the tested strains (188). Notably, for 46 of the strains, the identification differed from the previous attribution., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

We investigated the potential probiotic properties of indigenous lactic acid bacteria (LAB) isolated from Serbian homemade cheese. Seventeen LAB strains were isolated and characterised using standard protocols. One of the strains showed several probiotic properties: survival at low pH and in bile salts solution, antimicrobial activity, susceptibility to antibiotics and adhesion to hexodecane. DNA analysis identified the isolate as Lactobacillus casei, hereafter named L. casei 5s. The lipid lowering effect of L. casei 5s was evaluated in vivo using a hyperlipidemic rat model. Orally administered L. casei 5s significantly decreased the elevated total serum cholesterol and triglycerides, and attenuated macro vesicular steatosis in the liver. Moreover, L. casei 5s improved the intestinal microbial balance in favour of lactobacilli, while decreasing the number of Escherichia coli cells. The bacteria were re-isolated and identified from the surface of the intestinal mucosa and from the faecal samples of treated animals, indicating adhesiveness and colonisation ability. The results of an acute oral toxicity study in mice and the absence of translocation to other organs demonstrated the safety of the strain. In conclusion, L. casei 5s demonstrated promising probiotic potential and might be a good candidate for more detailed investigations.

Ready-to-eat foods have nowadays become a significant portion of the diet. Accordingly, nutritional composition of these food categories should be well-known, in particular its folate content. However, there is a broad lack of folate data in food composition tables and databases. A total of 21 fresh-cut vegetable and fruit packed products were analysed for total folate (TF) content using a validated method that relies on the folate-dependent growth of chloramphenicol-resistant Lactobacillus casei subspecies rhamnosus (NCIMB 10463). Mean TF content ranged from 10.0 to 140.9μg/100g for the different matrices on a fresh weight basis. Higher TF quantity, 140.9-70.1μg/100g, was found in spinach, rocket, watercress, chard and broccoli. Significant differences were observed between available data for fresh vegetables and fruits from food composition tables or databases and the analysed results for fresh-cut packed products. Supplied data support the potential of folate-rich fresh-cut ready-to-eat vegetables to increase folate intake significantly., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Gut microbiota (GM) dysbiosis has been linked to obesity and its metabolic complications such as cardiovascular disease (CVD). The risk of developing CVD increases with elevated concentration of serum triacylglycerol (TAG). In a blinded, randomised two-arm parallel human intervention study we have previously found that four weeks of supplementation with Lactobacillus paracasei subsp. paracasei L. casei W8® (L. casei W8) compared to placebo reduced the concentration of TAG in 64 young healthy adults, an effect, likely mediated by a decreased stearoyl- CoA desaturase-1 (SCD1) activity. In the present study we analysed faecal samples obtained during the intervention study to investigate whether this effect was related to the ability of L. casei W8 to colonise the human gut after supplementation of L. casei W8 (1010 cfu daily) as determined by qPCR specific for L. paracasei and L. casei (L. casei group); whether L. casei W8 consumption affected GM composition as determined by 16S rRNA gene targeted 454/FLX amplicon sequencing; and whether these changes were associated with changes in TAG concentration and SCD1 activity. Faecal samples were collected at baseline, after four weeks supplementation and two weeks after the supplementation was ended, and fasting blood samples were collected at baseline and after 4 weeks. Four weeks supplementation with L. casei W8 did not affect the overall composition of the GM; however, an increase in the relative abundance of the L. casei group from 8.48×10-6% of the total GM compared to 2.83×10-3% at baseline (P<0.001) was observed. Two weeks after supplementation ended, the relative abundance of the L. casei group was still increased 14 times compared to before the intervention (P<0.01). However, neither the increase in the abundance of the L. casei group nor overall GM composition correlated with changes in blood lipids or SCD1 activity.

Background: In the present investigation, the effect of Aloe vera gel powder on angiotensin-converting enzyme (ACE) inhibitory activity, extent of proteolysis during fermentation and survival of Lactobacillus casei NCDC19 during storage of fermented milk was studied., Results: Among the different cultures screened for ACE inhibitory activity, Lactobacillus casei NCDC 19 exhibited the highest ACE inhibition (approx. 40%) as well as extent of proteolysis (0.37, Abs₃₄₀). In the presence of Aloe vera (0.5% and 1% w/v) an increase in extent of proteolysis (0.460 ± 0.047 and 0.480 ± 0.027) and percent ACE inhibitory activity (44.32 ± 2.83 and 47.52 ± 1.83) was observed in comparison to control. Aloe vera powder addition also led to an increase in viable counts (>11 log cfu mL⁻¹) of L. casei NCDC 19 in fermented milk during storage for 7 days and the counts were maintained in sufficiently higher numbers., Conclusion: The study suggests Aloe vera to be a good functional ingredient which can be further explored for different health attributes., (© 2014 Society of Chemical Industry.)