Isolation and Selection of Potential Probiotic Bacteria from the Pig Gastrointestinal Tract

The present study aimed to isolate bacterial strains from the pig gastrointestinal tract that have antagonistic activity against potential pathogens and are able to produce antimicrobial compounds. That ability would be a first requirement for the strains’ possible use as probiotics. Samples obtained from pig intestinal mucosa and contents were screened for the presence of antagonistic activity against pathogenic indicator strains of Escherichia coli, Salmonella, and Listeria by means of the double-layer technique. Samples displaying the largest inhibitory halos were further studied for the production of inhibitory substances using the agar diffusion and microtitration methods. The three most promising isolates were identified by sequencing of the 16S rRNA gene and showed highest affiliation to Lactobacillus salivarius. Optimal growth conditions and bacteriocin production were recorded in de Man, Rogosa, and Sharpe broth under anaerobic conditions at 37 °C. The antimicrobial substances were found to be sensitive to proteolytic enzymes but showed good stability at pH values below 6. Our findings suggest that these three intestinal strains are able to produce antimicrobial substances capable of inhibiting the growth of potential enteric pathogens and might have potential as probiotic feed additives for the prevention of gastrointestinal diseases.     

Enrofloxacin and Probiotic Lactobacilli Influence PepT1 and LEAP-2 mRNA Expression in Poultry

Expression of peptide transporter 1 (PepT1) and liver-expressed antimicrobial peptide 2 (LEAP-2) in chickens can be influenced by food deprivation, pathological conditions and drug administration. Effect of three putative probiotic Lactobacillus strains and enrofloxacin on the expression of PepT1 and LEAP-2 mRNA was investigated in Ross 308 chickens. One-day-old chicks (n = 24) were allocated to following groups: control (without treatment); group treated with probiotics via feed; group treated with a combination of probiotics and enrofloxacin; and a group given enrofloxacin only. The drug was administered at a dose of 10 mg kg^?1, via drinking water for 5 days. Samples from liver, duodenum and jejunum were collected 126 h after the start of the treatment. Expression levels of PepT1 and LEAP-2 were determined by real-time polymerase chain reaction and were statistically evaluated by Mann–Whitney test. Enrofloxacin administered alone or in combination with probiotics provoked a statistically significant up-regulation of PepT1 mRNA levels in the measured organ sites. These changes can be attributed to a tendency of improvement in utilization of dietary peptide and in body weight gain. LEAP-2 mRNA expression levels did not change significantly in enrofloxacin-treated chickens in comparison with control group.     

Antibacterial,anti-inflammatory and probiotic potential of Enterococcus hirae isolated from the rumen of Bos primigenius

In the present study bacterial strains were isolated from the rumen fluids of Bos primigenius and investigated their in vitro probiotic properties with potent antibacterial activity and anti-inflammatory effects. 9 g positive bacterial isolates were obtained and three isolates could able to tolerate gastric conditions, high bile salt concentrations and exhibited significant bactericidal effect against the enteric pathogens Vibrio cholera, Enterococcus faecalis, Enterobacter aerogens, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi. Moreover it showed above 70 % cell surface hydrophobicity, significant low-invasion ability and potential adherence capacity in Caco-2 cells when compared with the control. The proinflammatory cytokines (TNF-α) was greatly reduced in rumen bacteria treatment and ARBS-1 modulate the immune response by activating the IL-4 secretion in parallel to TNF-α suppression. The 16s rRNA gene sequence of the active isolates were identified as Enterococcus hirae (ARBS-1), Pediococcus acidilactici (ARBS-4) and Bacillus licheniformis (ARBS-7). This study revealed the probiotic bactericidal properties of E. hirae obtained from the rumen of B. primigenius with potential antibacterial and anti-inflammatory effects. Future studies with the strains may yield some novel probiotic product for livestock’s.     

In Vitro Evaluation of the Probiotic Potential of Halotolerant Lactobacilli Isolated from a Ripened Tropical Mexican Cheese

Three halotolerant lactobacilli (Lactobacillus plantarum, L. pentosus, and L. acidipiscis) isolated from a ripened Mexican tropical cheese (double cream Chiapas cheese) were evaluated as potential probiotics and compared with two commercial probiotic strains (L. casei Shirota and L. plantarum 299v) from human origin. All the strains survived the in vitro gastrointestinal simulation from the oral cavity to the ileum. During the stomach simulation, all the strains survived in satiety conditions (60 min, pH 3.0, 3 g/L pepsin, 150 rpm) and only L. pentosus could not survive under fasting conditions (60 min, pH 2.0, 3 g/L pepsin, 150 rpm). All the strains showed a strong hydrophilic character with low n-hexadecane and a variable chloroform affinity. L. plantarum showed a mucin adhesion rate similar to that of L. plantarum 299v and L. casei Shirota, while L. pentosus and L. acidipiscis had a lower mucin adhesion. The isolated halotolerant lactobacilli exhibited similar antimicrobial activity against some gram-positive and gram-negative pathogens in comparison with the two commercial strains. In addition, the proteinaceous character of the antimicrobial agents against the most pathogenic strains was demonstrated. The compounds showed a low molecular weight (less than 10 kDa). Besides, L. plantarum and L. acidipiscis were able to produce the enzyme β-galactosidase. Finally, L. pentosus was able to deconjugate taurocholic, taurodeoxycholic, glycocholic, and glycodeoxycholic acids better than the two commercial strains analyzed. All these results suggest that the halotolerant lactobacilli isolated from this ripened Mexican cheese could be potentially probiotic. This is the first time that halotolerant lactic acid bacteria have been shown to have probiotic properties.     

Identification of Bacillus Strains for Biological Control of Catfish Pathogens

Bacillus strains isolated from soil or channel catfish intestine were screened for their antagonism against Edwardsiella ictaluri and Aeromonas hydrophila, the causative agents of enteric septicemia of catfish (ESC) and motile aeromonad septicaemia (MAS), respectively. Twenty one strains were selected and their antagonistic activity against other aquatic pathogens was also tested. Each of the top 21 strains expressed antagonistic activity against multiple aquatic bacterial pathogens including Edwardsiella tarda, Streptococcus iniae, Yersinia ruckeri, Flavobacterium columnare, and/or the oomycete Saprolegnia ferax. Survival of the 21 Bacillus strains in the intestine of catfish was determined as Bacillus CFU/g of intestinal tissue of catfish after feeding Bacillus spore-supplemented feed for seven days followed by normal feed for three days. Five Bacillus strains that showed good antimicrobial activity and intestinal survival were incorporated into feed in spore form at a dose of 8×10⁷ CFU/g and fed to channel catfish for 14 days before they were challenged by E. ictaluri in replicate. Two Bacillus subtilis strains conferred significant benefit in reducing catfish mortality (P<0.05). A similar challenge experiment conducted in Vietnam with four of the five Bacillus strains also showed protective effects against E. ictaluri in striped catfish. Safety of the four strains exhibiting the strongest biological control in vivo was also investigated in terms of whether the strains contain plasmids or express resistance to clinically important antibiotics. The Bacillus strains identified from this study have good potential to mediate disease control as probiotic feed additives for catfish aquaculture.     

Genetic differ in TLR4 gene polymorphisms and expression involved in Salmonella natural and artificial infection respectively in Chinese native chicken breeds

Salmonella enteritidis (SE) is a foodborne pathogen that negatively affects both animal and human health. Genetic variations in response to pathogenic SE colonization or to SE vaccination were measured in chicken resource populations. Toll-like receptor 4 (TLR4) is part of a group of evolutionarily conserved pattern recognition receptors involved in the activation of the immune system in response to various pathogens and in the innate defense against infection. In this study, TLR4 was investigated the association of TLR4 gene polymorphisms with Salmonella natural infection situation of birds from two distinct Chinese genetic breeds. One SNP G1894C in the second intron of chicken TLR4 (chTLR4) was scanned in the two hens breed, which showed significant association with Salmonella natural infection situation (P < 0.05). Genetic variations in response to pathogenic SE colonization also existed in distinct Chinese chicken resource population. In this study, mRNA expression of TLR4 was detected to investigate the association with the effect of artificial SE challenge in heterophil granulocytes and spleen of chicks from two distinct Chinese genetic breeds at 1, 3 and 10 day post-infection during the acute infection period. It clearly showed that young chicks’ response to SE infection was regulated by TLR4 mRNA expression. The results suggest that genetics, time, gender, and interactions among these factors, play important roles in TLR4 mRNA basic values and copies modulation of SE mediated immune response in distinct Chinese chickens.     

Simultaneous and rapid detection of enteric pathogens from raw milk by multiplex PCR

Enteroinvasive Escherichia coli (EIEC), heat-labile enterotoxin (LT) E. coli, Shigella spp., and Salmonella spp. are common enteric pathogens, which cause food-borne diseases if consumed in contaminated milk products. The rapid and reliable methods for detecting are imperative for reduction in hazard of infection. In this study, we selected primers, optimized the polymerase chain reaction (PCR) conditions, and analyzed the sensitivity and specificity of the multiplex PCR assay to screen raw milk from these enteric bacteria. Furthermore, EIEC, LT-E. coli, Shigella spp., Salmonella spp., and 11 non-targeted pathogenic strains were performed for the specificity of the multiplex PCR. Specific bands showed in EIEC, LT-E. coli, Shigella spp., and Salmonella spp. but no bands showed in other 11 pathogenic strains. The sensitivity of multiplex PCR was relatively high, was rounded to 200 CFU/ml (Shigella spp. and EIEC), 320 CFU/ml (Salmonella spp.), and 100 CFU/ml (LT-E. coli). This method for simultaneous and rapid detection of enteric pathogens (EIEC, LT-E. coli, Shigella spp., and Salmonella spp.) in raw milk showed high sensitivity and specificity, and led to faster track to report results.     

<Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> as a Probiotic Potential from Kouzeh Cheese (Traditional Iranian Cheese) and Its Antimicrobial Activity

The aim of this study is to isolate and identify Lactobacillus plantarum isolates from traditional cheese, Kouzeh, and evaluate their antimicrobial activity against some food pathogens. In total, 56 lactic acid bacteria were isolated by morphological and biochemical methods, 12 of which were identified as Lactobacillus plantarum by biochemical method and 11 were confirmed by molecular method. For analyzing the antimicrobial activity of these isolates properly, diffusion method was performed. The isolates were identified by 318 bp band dedicated for L. plantarum. The isolated L. plantarum represented an inhibitory activity against four of the pathogenic bacteria and showed different inhibition halos against each other. The larger halos were observed against Staphylococcus aureus and Staphylococcus epidermidis (15 ± 0.3 and 14.8 ± 0.7 mm, respectively). The inhibition halo of Escherichia coli was smaller than that of other pathogen and some L. plantarum did not show any inhibitory activity against E. coli, which were resistant to antimicrobial compounds produced by L. plantarum. The isolated L. plantarum isolates with the antimicrobial activity in this study had strong probiotic properties. These results indicated the nutritional value of Kouzeh cheese and usage of the isolated isolates as probiotic strains.     

Evaluation of probiotic properties of Lactobacillus plantarum strains isolated from Chinese sauerkraut

Lactobacillus plantarum strains isolated and identified from naturally-fermented Chinese sauerkraut were examined in vitro for potential probiotic properties and in vivo for cholesterol-lowering effect in mice. Among 7 isolated L. plantarum strains, strains S2-5 and S4-1 were found to possess desirable probiotic properties including ability to survive at pH 2.0 for 60 min, tolerate pancreatin and bile salts, adhere to Caco-2 cells, produce high β-galactosidase activity and antimicrobial activity against Escherichia coli O157 and Shigella flexneri CMCC(B). In addition, strains S2-5 and S4-1 were susceptible to several antibiotics, and capable of reducing cholesterol level in MRS medium by assimilation of cholesterol at 20.39 and 22.28 μg ml^?1, respectively. The in vivo study with L. plantarum S4-1 showed that feeding with fermented milk containing this strain was able to effectively reduce serum cholesterol level in mice, demonstrating its potential as an excellent probiotic candidate for applications in functional products.     

Investigation of antibacterial activity of Bacillus spp. isolated from the feces of Giant Panda and characterization of their antimicrobial gene distributions

Bacillus group is a prevalent community of Giant Panda’s intestinal flora, and plays a significant role in the field of biological control of pathogens. To understand the diversity of Bacillus group from the Giant Panda intestine and their functions in maintaining the balance of the intestinal microflora of Giant Panda, this study isolated a significant number of strains of Bacillus spp. from the feces of Giant Panda, compared the inhibitory effects of these strains on three common enteric pathogens, investigated the distributions of six universal antimicrobial genes (ituA, hag, tasA, sfp, spaS and mrsA) found within the Bacillus group by PCR, and analyzed the characterization of antimicrobial gene distributions in these strains using statistical methods. The results suggest that 34 strains of Bacillus spp. were isolated which has not previously been detected at such a scale, these Bacillus strains could be classified into five categories as well as an external strain by 16S rRNA; Most of Bacillus strains are able to inhibit enteric pathogens, and the antimicrobial abilities may be correlated to their categories of 16S rRNA; The detection rates of six common antimicrobial genes are between 20.58 %(7/34) and 79.41 %(27/34), and genes distribute in three clusters in these strains. We found that the antimicrobial abilities of Bacillus strains can be one of the mechanisms by which Giant Panda maintains its intestinal microflora balance, and may be correlated to their phylogeny.     

Multiplex PCR and DNA array for the detection of Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella spp. targeting virulence-related genes

A multiplex PCR and DNA array for quick detection of Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella spp. was developed using specific genetic markers derived from virulence-related genes. The genetic markers of cytK, sei, prfA, rfB, and hilA gene specifically amplified DNA fragments of 320 bp, 500 bp, 700 bp, 1.0 kb and 1.2 kb from B. cereus, S. aureus, L. monocytogenes, E. coli O157:H7, and Salmonella spp., respectively. These markers are specific for the detection of the corresponding target pathogens. The sensitivity of the genetic markers was down to ～0.5 fg genomic DNA and ～10¹ CFU/ml (one bacterial cell per reaction) of bacterial culture. The combination of mPCR and DNA macroarray hybridization sensitively and specifically detected B. cereus, S. aureus, L. monocytogenes, E. coli O157:H7, and Salmonella spp., in complex mixed cultures and food matrices. Thus, this mPCR and macroarray-based approach serves as rapid and reliable diagnostic tool for the detection of these five pathogens.     

In vitro evaluation of the antimicrobial activity of a range of probiotics against pathogens: Evidence for the effects of organic acids

The aim of this study was to investigate the antimicrobial properties of fifteen selected strains belonging to the Lactobacillus, Bifidobacterium, Lactococcus, Streptococcus and Bacillus genera against Gram-positive and Gram-negative pathogenic bacteria.In vitro antibacterial activity was initially investigated by an agar spot method. Results from the agar spot test showed that most of the selected strains were able to produce active compounds on solid media with antagonistic properties against Salmonella Typhimurium, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and Clostridium difficile. These results were also confirmed when cell-free culture supernatants (CFCS) from the putative probiotics were used in an agar well diffusion assay. Neutralization of the culture supernatants with alkali reduced the antagonistic effects. These experiments are able to confirm the capacity of potential probiotics to inhibit selected pathogens. One of the main inhibitory mechanisms may result from the production of organic acids from glucose fermentation and consequent lowering of culture pH. This observation was confirmed when the profile of organic acids was analysed demonstrating that lactic and acetic acid were the principal end products of probiotic metabolism.Furthermore, the assessment of the haemolytic activity and the susceptibility of the strains to the most commonly used antimicrobials, considered as basic safety aspects, were also studied.The observed antimicrobial activity was mainly genus-specific, additionally significant differences could be observed among species.     

Anti-salmonella properties of kefir yeast isolates: An in vitro screening for potential infection control

The rise of antibiotic resistance has increased the need for alternative ways of preventing and treating enteropathogenic bacterial infection. Various probiotic bacteria have been used in animal and human. However, Saccharomyces boulardii is the only yeast currently used in humans as probiotic. There is scarce research conducted on yeast species commonly found in kefir despite its claimed potential preventative and curative effects. This work focused on adhesion properties, and antibacterial metabolites produced by Kluyveromyces lactis and Saccharomyces unisporus isolated from traditional kefir grains compared to Saccharomyces boulardii strains. Adhesion and sedimentation assay, slide agglutination, microscopy and turbidimetry assay were used to analyze adhesion of Salmonella Arizonae and Salmonella Typhimurium onto yeast cells. Salmonella growth inhibition due to the antimicrobial metabolites produced by yeasts in killer toxin medium was analyzed by slab on the lawn, turbidimetry, tube dilution and solid agar plating assays. Alcohol and antimicrobial proteins production by yeasts in killer toxin medium were analyzed using gas chromatography and shotgun proteomics, respectively. Salmonella adhered onto viable and non-viable yeast isolates cell wall. Adhesion was visualized using scanning electron microscope. Yeasts-fermented killer toxin medium showed Salmonella growth inhibition. The highest alcohol concentration detected was 1.55%, and proteins with known antimicrobial properties including cathelicidin, xanthine dehydrogenase, mucin-1, lactadherin, lactoperoxidase, serum amyloid A protein and lactotransferrin were detected in yeasts fermented killer medium. These proteins are suggested to be responsible for the observed growth inhibition effect of yeasts-fermented killer toxin medium. Kluyveromyces lactis and Saccharomyces unisporus have anti-salmonella effect comparable to Saccharomyces boulardii strains, and therefore have potential to control Salmonella infection.     

Using In Vitro Immunomodulatory Properties of Lactic Acid Bacteria for Selection of Probiotics against Salmonella Infection in Broiler Chicks

Poultry is known to be a major reservoir of Salmonella. The use of lactic acid bacteria has become one of successful strategies to control Salmonella in poultry. The purpose of this study was to select lactic acid bacteria strains by their in vitro immunomodulatory properties for potential use as probiotics against Salmonella infection in broiler chicks. Among 101 isolated lactic acid bacteria strains, 13 strains effectively survived under acidic (pH 2.5) and bile salt (ranging from 0.1% to 1.0%) conditions, effectively inhibited growth of 6 pathogens, and adhered to Caco-2 cells. However, their in vitro immunomodulatory activities differed significantly. Finally, three strains with higher in vitro immunomodulatory properties (Lactobacillus plantarum PZ01, Lactobacillus salivarius JM32 and Pediococcus acidilactici JH231) and three strains with lower in vitro immunomodulatory activities (Enterococcus faecium JS11, Lactobacillus salivarius JK22 and Lactobacillus salivarius JM2A1) were compared for their inhibitory effects on Salmonella adhesion and invasion to Caco-2 cells in vitro and their antimicrobial effects in vivo. The former three strains inhibited Salmonella adhesion and invasion to Caco-2 cells in vitro, reduced the number of Salmonella in intestinal content, spleen and liver, reduced the levels of lipopolysaccharide-induced TNF-α factor (LITAF), IL-1β, IL-6 and IL-12 in serum and increased the level of IL-10 in serum during a challenge study in vivo more efficiently than the latter three strains. These results suggest that in vitro immunomodulatory activities could be used as additional parameters to select more effective probiotics as feed supplements for poultry.     

Investigation of the Antimicrobial Activity of Bacillus licheniformis Strains Isolated from Retail Powdered Infant Milk Formulae

This study investigated the potential antimicrobial activity of ten Bacillus licheniformis strains isolated from retail infant milk formulae against a range of indicator (Lactococcus lactis, Lactobacillus bulgaricus and Listeria innocua) and clinically relevant (Listeria monocytogenes, Staphylococcus aureus, Streptococcus agalactiae, Salmonella Typhimurium and Escherichia coli) microorganisms. Deferred antagonism assays confirmed that all B. licheniformis isolates show antimicrobial activity against the Gram-positive target organisms. PCR and matrix-assisted laser desorption ionization time-of-flight mass spectrometry analyses indicated that four of the B. licheniformis isolates produce the bacteriocin lichenicidin. The remaining six isolates demonstrated a higher antimicrobial potency than lichenicidin-producing strains. Further analyses identified a peptide of ~1,422 Da as the most likely bioactive responsible for the antibacterial activity of these six isolates. N-terminal sequencing of the ~1,422 Da peptide from one strain identified it as ILPEITXIFHD. This peptide shows a high homology to the non-ribosomal peptides bacitracin and subpeptin, known to be produced by Bacillus spp. Subsequent PCR analyses demonstrated that the six B. licheniformis isolates may harbor the genetic machinery needed for the synthesis of a non-ribosomal peptide synthetase similar to those involved in production of subpeptin and bacitracin, which suggests that the ~1,422 Da peptide might be a variant of subpeptin and bacitracin.     

Calcium-dependent antibacterial activity of donkey’s milk against <Emphasis Type="Italic">Salmonella</Emphasis>

The aim of this study was to examine the antibacterial activity of raw donkey’s milk (DM) against Salmonella Enteritidis and Salmonella Typhimurium as well as to determine the dependence of this antibacterial activity on calcium, lysozyme and lactoferrin content. Antibacterial assays were conducted in DM artificially contaminated with these Salmonella serotypes and then incubated at 38 °C for 8 hours. Calcium concentration was found to have a strong influence on the antibacterial activity of the contaminated DM samples supplemented with CaCl₂ and EDTA. The antibacterial activity of DM against the tested Salmonella strains was observed to be strongly calcium dependent, with the addition of CaCl₂ to DM samples improving its antibacterial potential against both pathogens. Salmonella Enteritidis appeared to be less sensitive to the antimicrobial agents in DM than S. Typhimurium. One explanation is the calcium-dependant antibacterial activity of DM is attributable to the calcium-binding ability of its lysozyme. Lysozyme may be the main antibacterial agent, most probably via a nonenzymatic mode of action against tested Salmonella strains.     

Sensitivity to Enterocins of Biogenic Amine-Producing Faecal Enterococci from Ostriches and Pheasants

Enterococci are widespread bacteria forming the third largest genus among lactic acid bacteria. Some possess probiotic properties or they can produce beneficial proteinaceous antimicrobial substances called enterocins. On the other hand, some enterococci produce biogenic amines (BAs), so this study is focused on the sensitivity to enterocins of biogenic amine-producing faecal enterococci from ostriches and pheasants. Altogether, 60 enterococci isolated from faeces of ostriches and pheasants were tested for production of BAs. This target of the identified enterococci involved 46 strains selected from 140 ostriches and 17 from 60 pheasants involving the species Enterococcus hirae, E. faecium, E. faecalis, and E. mundtii. Although BAs histamine, cadaverine, putrescine, and tryptamine were not detected in the enterococci tested, in general high BA production by the tested enterococci was noted. The species E. hirae formed the majority of the enterococcal strains from ostrichs faeces (34 strains). High production of tyramine (TYM) was measured with an average amount of 958.16 ± 28.18 mg/ml. Among the enterococci from pheasants, the highest was production of TYM compared to phenylethylamine, spermidine, and spermine. Enterococci featured high BA production; however, they were sensitive to seven enterocins with inhibition activity ranging from 100 up to 25,600 AU/ml.     

Selection of Potential Probiotic <Emphasis Type="Italic">Lactobacillus</Emphasis> with Inhibitory Activity Against <Emphasis Type="Italic">Salmonella</Emphasis> and Fecal Coliform Bacteria

Three hundred and sixty presumptive lactic acid bacteria (LAB) isolated from pregnant sows, newborn, suckling, and weaned piglets were preliminarily screened for anti-Salmonella activity. Fifty-eight isolates consisting of Lactobacillus reuteri (n = 32), Lactobacillus salivarius (n = 10), Lactobacillus mucosae (n = 8), Lactobacillus johnsonii (n = 5), and Lactobacillus crispatus (n = 3) were selected and further characterized for probiotic properties including production of antimicrobial substances, acid and bile tolerance, and cell adherence to Caco-2 cells. Eight isolates including Lact. johnsonii LJ202 and Lact. reuteri LR108 were identified as potential probiotics. LJ202 was selected for further use in co-culture studies of two-bacterial and multiple-bacterial species to examine its inhibitory activity against Salmonella enterica serovar Enteritidis DMST7106 (SE7106). Co-culture of LJ202 and SE7106 showed that LJ202 could completely inhibit the growth of SE7106 in 10 h of co-culture. In co-culture of multiple-bacterial species, culturable fecal bacteria from pig feces were used as representative of multiple-bacterial species. The study was performed to examine whether interactions among multiple-bacterial species would influence antagonistic activity of LJ202 against SE7106 and fecal coliform bacteria. Co-culture of SE7106 with different combinations of fecal bacteria and probiotic (LJ202 and LR108) or non-probiotic (Lact. mucosae LM303) strains revealed that the growth of SE7106 was completely inhibited either in the presence or in the absence of probiotic strains. Intriguingly, LJ202 exhibited notable inhibitory activity against fecal coliform bacteria while LR108 did not. Taken together, the results of co-culture studies suggested that LJ202 is a good probiotic candidate for further study its inhibitory effects against pathogen infections in pigs.     

Potential probiotic properties of phytase-producing Lactobacillus salivarius FC113

Probiotics have known efficacy as dietary supplements. Here, Lactobacillus strain F113 was characterized for probiotic use. Strain FC113 was selected as having the highest phytase activity (403.6 U) among tested strains showing acid tolerance and nitrite production. FC113 was tentatively identified as Lactobacillus salivarius based on an API 50 CHL assay and 16S rRNA gene analysis. The production of interleukin (IL)-1α and tumor necrosis factor (TNF)-α was measured in in vitro culture experiments. Cytokine production by L. salivarius FC113 at 1?×?10⁷ CFU/ml was approximately 175.5?±?36.40 pg/mL IL-1α and 353.5?±?61.79 pg/mL TNF-α. L. salivarius FC113 was profoundly resistant to artificial gastric juice (pH 2.5, 1 % pepsin), and persisted for 24 h in artificial bile acid. According to results obtained with an API ZYM kit, L. salivarius FC113 did not generate carcinogenic enzymes. L. salivarius F113 had an inhibitory effect on food-borne pathogens, and adhered strongly to HT-29 human intestinal epithelial cell lines. These results show that L. salivarius FC113 has probiotic characteristics, and exhibits high feed bioavailability in the host animal, in addition to an immune-stimulating effect.