Bacteriocinogenic activity of Enterococcus faecalis strains from chourico, traditional sausage produced in Southern Portugal

Enterococcus faecalis isolates from chourico (traditional Portugal fermented sausage) were studied here with the main impact on bacteriocin production. In bacteriocin-producing strains phenotypic antibiotic profile was tested to check if they are sensitive or resistant. Lactic acid production ranged from 0.581 mmol/L up to 0.783 mmo/L. Enterococci grew sufficiently in the medium with 1% concentration of oxgall/bile. From 14 E. faecalis, bacteriocin substances (Bs) by 8 strains were found to inhibit the growth at least 1 indicator of 27 (inhibitory zones-10 to 18 mm) by the qualitative method. The effect of Bs of 8 active E. faecalis strains was tested also by the quantitative method; Bs of 6 E. faecalis inhibited the growth at least of 1 indicator; E. faecalis P06/7, P06/13, P06/16 inhibited the growth of Enterococcus avium EA5, Listeria innocua LMG13568, Staphylococcus aureus SA5 (activity: 100 to 1600 AU/ml). The highest activity (1600 AU/ml) showed Bs produced by P06/16 against LMG13568. Taking into account the antibiotic sensitivity and activity in the strain itself, the most promising strains for detailed bacteriocin studies are E. faecalis P06/16, P06/7, P06/13 which are mostly antibiotic sensitive and bacteriocin active

Comparative Genome Analysis of Lactobacillus reuteri and Lactobacillus fermentum Reveal a Genomic Island for Reuterin and Cobalamin Production

Lactobacillus reuteri is a heterofermentative lactic acid bacterium that naturally inhabits the gut of humans and other animals. The probiotic effects of L. reuteri have been proposed to be largely associated with the production of the broad-spectrum antimicrobial compound reuterin during anaerobic metabolism of glycerol. We determined the complete genome sequences of the reuterin-producing L. reuteri JCM 1112T and its closely related species Lactobacillus fermentum IFO 3956. Both are in the same phylogenetic group within the genus Lactobacillus. Comparative genome analysis revealed that L. reuteri JCM 1112T has a unique cluster of 58 genes for the biosynthesis of reuterin and cobalamin (vitamin B12). The 58-gene cluster has a lower GC content and is apparently inserted into the conserved region, suggesting that the cluster represents a genomic island acquired from an anomalous source. Two-dimensional nuclear magnetic resonance (2D-NMR) with 13C3-glycerol demonstrated that L. reuteri JCM 1112T could convert glycerol to reuterin in vivo, substantiating the potential of L. reuteri JCM 1112T to produce reuterin in the intestine. Given that glycerol is shown to be naturally present in feces, the acquired ability to produce reuterin and cobalamin is an adaptive evolutionary response that likely contributes to the probiotic properties of L. reuteri

Characteristic and susceptibility to enterocins of enterococci in pheasants possessing virulence factor genes

With an increasing number of pheasants as gamebirds being reared each year, these species are becoming a more prominent part of the workload of many veterinary practices. Only limited information can be found concerning the microflora of common pheasants. A significant part of the obligate microflora consists of lactic acid bacteria, including enterococci. In this study, faeces were sampled from 60 pheasants aged 16-17 weeks. Enterococcal counts reached 5.48±1.9 (log10) CFU/g. Strains (17) were taxonomically classified to the genus Enterococcus using the Maldi-Tof identification system; they were allotted to the species E. hirae (58.8%), E. faecium (23.5%) and E. faecalis (17.7%) by highly probable species identification or by secure genus identification/probable species identication. Species allocation was also confirmed using conventional biochemical tests. Most strains formed β-hemolysis. Gelatinase active phenotype was found in three E. faecalis strains. Enterococci were β-glucuronidase negative, mostly trypsin negative with slight or moderate production of α-chymotrypsin. EH52b and EF42 strains possessed the highest potential for pathogenicity. Average value of lactic acid was 1.78±0.33 mmo/L. Most strains were tetracycline resistant (82.4%). Polyresistant E. faecalis strains with positive gelatinase phenotype and possessing virulence factor genes confirmed using PCR (gelE, efaAfs, ccf cob, cpd) were sensitive to enterocins (activity 1600-25 600 AU/mL)

Mode of binding of fibrinogen, fibronectin and iron-binding proteins by animal enterococci

Sixty-two animal enterococci were examined for their binding of bovine fibrinogen, porcine fibronectin, bovine lactoferrin, bovine apotransferrin and human holotransferrin in the particle agglutination assay (PAA). Individual strains expressed binding of selected glycoproteins to various degrees (0, 1, 2, 3), whereas bovine fibrinogen binding of enterococci from goats, rabbits and rodents was the strongest (3) in general. Porcine fibronectin was bound weakly (1 or 2) by enterococci from horses, dogs, poultry, rabbits and rodents, while most of the goat isolates and half of the dog feed isolates did not bind fibronectin (0). Bovine lactoferrin was bound especially by the isolates from rodents and rabbits. Bovine apotransferrin was bound very weakly (1) by only a few isolates. Human holotransferrin was bound to a greater extent than apotransferrin by some isolates from rabbits and rodents. Since multiresistant strains are preferred in our binding studies, enterococci were also examined for their antibiotic resistance pattern. Almost all investigated isolates were resistant at least to one antibiotic. However, some strains displayed resistance to five or six antibiotics of 10 antibiotics tested. In a study of the inhibitory effect of heparin, porcine mucin and hyaluronic acid, the greatest effect was observed after heparin treatment of bacterial cells. These observations, as well as the expression of heparin binding by most strains, may suggest that at least one mode of enterococcal attachment utilizes glycosaminoglycan chains present on the surface of adherent cells

Effect of combined administration of enterocin 4231 and sage in rabbits

Enterocin (Ent) 4231, produced by non-rabbit origin strain Enterococcus faecium CCM 4231 was used in combination with sage plant extract in rabbits with the aim to check their antimicrobial activity against microbiota, their effect on immunological, biochemical blood parameters, values of volatile fatty acids in caecum, Eimeria sp. oocysts occurrence and selected parameters of rabbits meat. The animals were divided into three experimental groups (EG1-Ent 4231; EG2- sage; EG3- Ent 4231 with sage) and control group (CG); 24 rabbits in each. Natural substances (NS) were administered for 21 days. The experiment lasted for 42 days. The reduction of microbiota in faeces was observed in EG3 at day 21 by a decrease in the numer of coagulase-positive staphylococci (P<0.01) in comparison with that determined in CG. The bacterial counts in the caecum were lower than those found in faeces. A decrease in the numer of Pseudomonas-like sp. in caeca of the experimental groups was observed at days 21 and 42 (difference in range 0.40-1.87 log cycles) comparing with that determined in CG. At day 21, a significant increase in phagocytic activity (PA, P<0.001) was found in blood of rabbits from EG2 comparing with that observed in CG. At day 42, a significant increase in PA (P<0.001) was determined in all experimental groups in comparison with CG. At day 21, in caecal content of EG3 significantly higher values of lactic acid were observed (P<0.05) in comparison with those found in CG. The reduction of Eimeria sp. oocysts was demonstrated after application of each of NS. Addition of NS did not influence biochemical parameters, meat quality of the animals and does not influence negatively the health status of rabbits

Combined administration of bacteriocin-producing, probiotic strain Enterococcus faecium CCM7420 with Eleutherococcus senticosus and their effect in rabbits

The effect of Enterococcus faecium CCM7420 (EF) – enterocin-producing and probiotic strain of rabbit origin, Eleutherococcus senticosus extract (ES) and their combination (ES+EF) was determined on selected bacteria in faeces and caecum content, leukocytes phagocytosis, blood biochemistry and growth performance. Ninety-six weaned rabbits were divided into 3 experimental (ES, EF, ES+EF) and control group (CG). The rabbits in the groups ES and EF+ES were fed commercial diet enriched with E. senticosus extract (30 g/100 kg feed), rabbits in groups EF and CG were fed untreated diet. The rabbits in the EF and ES+EF groups were administered with an overnight culture of E. faecium CCM7420 strain (500 μl/animal/day into water, 109 CFU/ml). The treatment period lasted 21 days. The microbiological examinations in faecal samples confirmed the presence of E. faecium CCM7420 strain. In groups EF and ES+EF, the reduction of faecal coliforms, Pseudomonas-like sp., Clostridium-like sp. and S. aureus was recorded. Leucocyte phagocytosis significantly increased in all experimental groups (P<0.0001) compared to CG. The lowest GPx values were measured in the ES+EF group. Higher total protein, triglycerides and calcium concentrations were detected in experimental groups compared to CG. The cholesterol concentration decreased in the ES group. The highest average daily gain was recorded in EF group; in ES+EF the better feed conversion ratio and no mortality was recorded. These results indicated that the dietary supplementation with the E. faecium CCM7420 and E. senticosus extract stimulate the leukocytes phagocytosis and reduces the potential pathogens in rabbits digestive tract without oxidative stress and improve the growth performance

Effect of thyme oil on small intestine integrity and antioxidant status, phagocytic activity and gastrointestinal microbiota in rabbits

The effects of 0.5 g thyme oil per kg dry matter (DM) of diet on duodenal tissue integrity, antioxidant status, phagocytic activity and selected microbiota in the caecum and faeces of rabbits were studied. Twenty-four rabbits were divided into two groups and were fed a commercial granulated diet for growing rabbits (CD) with access to water ad libitum. The first group was fed the CD, while to the CD of the second group thyme oil was added. Intestinal integrity was tested by measuring the transepithelial electrical resistance (TEER). Thyme oil significantly increased the value of total antioxidant status (TAS) in the blood plasma and glutathione peroxidase (GPx) activity in the liver, and it decreased malondialdehyde (MDA) concentration in the duodenal tissue. Thyme oil resulted in strengthened intestinal integrity, as the essential oil supplementation significantly increased TEER values in the experiment. The faecal microbiota of rabbits was almost completely balanced in both groups, and only a slight decrease was found in the microbial population at day 42 of the trial. In both groups, the bacterial counts were generally lower in the caecum than in the faecal samples. In conclusion, dietary supplementation with 0.5 g/kg DM thyme oil may improve intestinal integrity, and it may have an antioxidant effect. A tendency was also found for thyme oil to stimulate the abundance of some microbes beneficial in the rabbit gut