Biomedical subjects

S Ahrné

Publications and source records attributed to S Ahrné.

At least 19 recordsLinked to original sources

PubMed2006

Rose hip and Lactobacillus plantarum DSM 9843 reduce ischemia/reperfusion injury in the mouse colon.

Ischaemia/reperfusion (I/R) of the colon is an inflammatory condition that leads to tissue injury where reactive oxygen species play a central role. Rose hip is rich in biologically active polyphenols with antioxidative properties, which may be important in prevention of lipid peroxidation. L. plantarum DSM 9843 possesses enzymatic activity towards polyphenols. The objective of this study was to define the effect of oral administration of L. plantarum and rose hip in I/R injury. Administration of rose hip and L. plantarum significantly decreased MDA levels in caecum tissue and Enterobacteriaceae counts in caecum stool. A positive correlation between MDA levels and Enterobacteriaceae counts was found. The results support a synergistic/additive role of rose hip and L. plantarum in reducing lipid peroxidation. Therefore rose hip and L. plantarum may be used as a pretreatment to tissue injuries, e.g. colonic surgery, organ transplantation and vascular surgery.

Animals↗

PubMed2004

T-RFLP combined with principal component analysis and 16S rRNA gene sequencing: an effective strategy for comparison of fecal microbiota in infants of different ages.

The fecal microbiota of two healthy Swedish infants was monitored over time by terminal restriction fragment length polymorphism (T-RFLP) analysis of amplified 16S rRNA genes. Principal component analysis (PCA) of the T-RFLP profiles revealed that the fecal flora in both infants was quite stable during breast-feeding and a major change occurred after weaning. The two infants had different sets of microbiota at all sampling time points. 16S rDNA clone libraries were constructed and the predominant terminal restriction fragments (T-RFs) were identified by comparing T-RFLP patterns in the fecal community with that of corresponding 16S rDNA clones. Sequence analysis indicated that the infants were initially colonized mostly by members of Enterobacteriaceae, Veillonella, Enterococcus, Streptococcus, Staphylococcus and Bacteroides. The members of Enterobacteriaceae and Bacteroides were predominant during breast-feeding in both infants. However, Enterobacteriaceae decreased while members of clostridia increased after weaning. T-RFLP in combination with PCA and 16S rRNA gene sequencing was shown to be an effective strategy for comparing fecal microbiota in infants and pointing out the major changes.

Base Sequence↗

PubMed2003

The Yersinia HPI is present in Serratia liquefaciens isolated from meat.

AIMS: The aim of the study was to screen the Enterobacteriaceae flora of meat for the presence of bacteria harbouring the Yersinia high-pathogenicity island (HPI). METHODS AND RESULTS: Bacteria from 29 meat and 29 liver samples were isolated on violet-red bile glucose agar. A total of 197 isolates were screened for the presence of the irp2 gene, encoded within the HPI, by PCR. One isolate that was positive for irp2 gene was also positive for the fyuA, irp1, ybtP/ybtQ, ybtX/ybtS and int/asn tRNA genes by PCR. The presence of fyuA, irp1 and irp2 genes was confirmed by Southern hybridization. CONCLUSIONS: The isolate was identified as Serratia liquefaciens by sequencing of the 16S rRNA gene and by ribotyping. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of a Serratia harbouring the Yersinia HPI. Serratia is a frequently occurring Enterobacteriaceae genus in chill-stored meat.

Animals↗

PubMed2001

Effects of different probiotic strains of Lactobacillus and Bifidobacterium on bacterial translocation and liver injury in an acute liver injury model.

Septic complications represent frequent causes of morbidity in liver diseases and following hepatic operations. Most infections are caused by the individual own intestinal microflora. The intestinal microflora composition is important in physiological and pathophysiological processes in the human gastrointestinal tract, but their influence on liver in different situations is unclear. We therefore studied the effect of different Lactobacillus strains and a Bifidobacterium strain on the extent of liver injury, bacterial translocation and intestinal microflora in an acute liver injury model. Sprague-Dawley rats were divided into five groups: acute liver injury control, acute liver injury + B. animalis NM2, acute liver injury + L. acidophilus NMI, acute liver injury + L. rhamnosus ATCC 53103, and acute liver injury + L. rhamnosus DSM 6594 and L. plantarum DSM 9843. The bacteria were administered rectally daily for 8 days. Liver injury was induced on the 8th day by intraperitoneal injection of D-galactosamine (1.1 g/kg BW). Samples were collected 24 h after the liver injury. Liver enzymes and bilirubin serum levels, bacterial translocation (to arterial and portal blood, liver and mesenteric lymph nodes (MLNs)), and intestinal microflora were evaluated. L. acidophilus NM1; L. rhamnosus ATCC 53103, and L. rhamnosus DSM 6594 + L. plantarum DSM 9843 decreased bacterial translocation compared to the liver injury control group. B. animalis NM2 increased bacterial translocation to the mesenteric lymph nodes. The levels of alanine aminotransferase (ALAT) were significantly lower in the L. acidophilus, L. rhamnosus ATCC 53103, L. rhamnosus DSM 6594 + L. plantarum DSM 9843 groups compared to the liver injury group. The L. rhamnosus and L. rhamnosus + L. plantarum groups significantly reduced ALAT levels compared to the B. animalis group. All administered bacteria decreased the Enterobacteriaceae count in the cecum and colon. Administration of different lactobacilli and a Bifidobacterium strain in an acute liver injury rat model, has shown different effects on bacterial translocation and hepatocellular damage. L. acidophilus, L. rhamnosus, and L. rhamnosus + L. plantarum reduced bacterial translocation and hepatocellular damage. B. animalis NM2 increased bacterial translocation to the mesenteric lymph nodes and did not affect hepatocellular damage.

Alanine Transaminase↗

PubMed2001

Randomly amplified polymorphic DNA (RAPD) profiles for the distinction of Lactobacillus species.

Forty-one type and reference strains of Lactobacillus were evaluated using their randomly amplified polymorphic DNA band profiles. Developed bands for each strain were distinct and enabled discrimination. The best correlations were obtained applying the Pearson product moment correlation coefficient (r) together with the unweighted pair group method using arithmetic averages algorithm. All of the strains were clearly differentiated at and below the 72% similarity value. Species discrimination might be possible making use of the distinctly polymorphic bands amplified specific to a strain.

Bacterial Typing Techniques↗

PubMed2001

Identification of enterococcal isolates by temperature gradient gel electrophoresis and partial sequence analysis of PCR-amplified 16S rDNA variable V6 regions.

Based on partial sequence analysis of PCR-amplified 16S rDNA variable V6 regions of 14 enterococcal type strains, Enterococcus faecalis, Enterococcus mundtii, Enterococcus gallinarum, Enterococcus avium, Enterococcus raffinosus and Enterococcus saccharolyticus showed characteristic sequence motifs which made it possible to separate them into six individual species lines. Furthermore, two species cluster groups could be identified, including (i) Enterococcus faecium, Enterococcus durans, Enterococcus hirae, Enterococcus malodoratus, and (ii) Enterococcus casseliflavus/Enterococcus flavescens, Enterococcus pseudoavium, Enterococcus dispar and Enterococcus sulfureus. There were identical DNA sequences in the V6 region within each group. Temporal temperature gradient gel electrophoresis (TTGE) of the PCR products from 16 type strains, 12 enterococcal reference strains and 8 clinical isolates revealed that a single nucleotide divergence in DNA sequences was sufficient for separation, identification and division of the studied enterococcal strains into corresponding TTGE profiles. It was concluded that partial DNA sequence analysis and TTGE profiling of PCR-amplified 16S rDNA variable V6 regions provide useful tools for the identification of clinically important Enterococcus spp.

Bacterial Typing Techniques↗

PubMed2001

Temporal temperature gradient gel electrophoresis (TTGE) as a tool for identification of Lactobacillus casei, Lactobacillus paracasei, Lactobacillus zeae and Lactobacillus rhamnosus.

AIMS: To develop a tool for rapid and inexpensive identification of the Lactobacillus casei complex. METHODS AND RESULTS: Lactobacillus casei, Lactobacillus paracasei, Lactobacillus zeae and Lactobacillus rhamnosus were identified by PCR-amplification of the segment between the U1 and U2 regions of 16S rDNA (position 8-357, Escherichia coli numbering) and temporal temperature gradient gel electrophoresis (TTGE). Seven tested Lact. paracasei strains were divided into three TTGE-subgroups. CONCLUSION: TTGE successfully distinguished between the closely-related target species. TTGE is also a powerful method for revealing sequence heterogeneities in the 16S rRNA genes. SIGNIFICANCE AND IMPACT OF THE STUDY: Due to rapid and easy performance, TTGE of PCR-amplified 16S rDNA fragments will be useful for the identification of extended numbers of isolates.

Bacterial Typing Techniques↗

PubMed2000

Temperature-dependent variation in API 50 CH fermentation profiles of Lactobacillus species.

API 50 CH fermentation profiles of 45 Lactobacillus, one Atopobium, and three Weissella strains incubated at 30 degrees C and 37 degrees C were evaluated. Atopobium uli and ten species of Lactobacillus showed stable patterns despite the change in temperature. The rest of the type strains showed discrepancy between the two incubation temperatures: 18 strains lost, 12 additionally fermented another sugar, and 7 others fermented a different one in lieu. The variation was maximum in L. delbrueckii subsp. delbrueckii. L. malefermentans failed to ferment any of the substrates at 37 degrees C. Majority of the food and plant-associated strains (mainly heterofermenters) retained distinctive traits at 30 degrees C, while most of the animal-associated strains (mostly homofermenters) did so at 37 degrees C. No general trend was observed; 30 degrees C appeared to promote heterofermentation, while 37 degrees C favored homofermenters. Use of API 50 CH profiles for taxonomic purpose in most lactobacilli appears reproducible if a specific temperature for a species is strictly followed.

Fermentation↗

PubMed2000

Probiotics and immune response.

Current evidence supports the concept that oral administration of probiotic lactobacilli may be therapeutic in preventing antibiotic-associated diarrhea in children and in reestablishing normal flora in the gastrointestinal tract. Children with human immunodeficiency virus (HIV) infections may have episodes of diarrhea and frequently experience malabsorption associated with possible bacterial overgrowth; together these may interact to produce the growth abnormalities characteristic of this group. The overall objective of this investigation has been to determine whether oral administration of the probiotic Lactobacillus plantarum 299v could improve nutrient status and promote growth in children congenitally exposed to HIV. In addition, the possible beneficial effect of Lactobacillus plantarum 299v in modulating immune response was evaluated. In preliminary results described here, we report on the ability of Lactobacillus plantarum 299v to colonize children with HIV and to elicit specific systemic immune response after oral supplementation.

Child↗

PubMed2000

Phylogenetic evidence for novel and genetically different intestinal spirochetes resembling Brachyspira aalborgi in the mucosa of the human colon as revealed by 16S rDNA analysis.

Intestinal spirochetes (Brachyspira spp.) are causative agents of intestinal disorders in animals and humans. Phylogenetic analysis of cloned 16S rRNA genes from biopsies of the intestinal mucosa of the colon from two Swedish 60-years old adults without clinical symptoms revealed the presence of intestinal spirochetes. Seventeen clones from two individuals and 11 reference strains were analyzed and the intestinal spirochetes could be divided into two lineages, the Brachyspira aalborgi and the Brachyspira hyodysenteriae lineages. All of the clones grouped in the B. aalborgi lineage. Moreover, the B. aalborgi lineage could be divided into three distinct phylogenetic clusters as confirmed by bootstrap and signature nucleotide analysis. The first cluster comprised 6 clones and the type strain B. aalborgi NCTC 11492T. The cluster 1 showed a 16S rRNA gene similarity of 99.4-99.9%. This cluster also harbored the only other strain of B. aalborgi isolated so far, namely strain W1, which was subjected to phylogenetic analysis in this work. The second cluster harbored 9 clones with a 98.7 to 99.5% range of 16S rDNA similarity to the B. aalborgi cluster 1. Two clones branched distinct and early of the B. aalborgi line forming the third cluster and was found to be 98.7% similar to cluster 1 and 98.3-99.1% to cluster 2. Interestingly, this shows that considerable variation of intestinal spirochetes can be found as constituents of the colonic microbiota in humans, genetically resembling B. aalborgi. The presented data aid significantly to the diagnostic and taxonomic work on these organisms.

Cell Lineage↗

PubMed2000

Alteration of intestinal microflora is associated with reduction in abdominal bloating and pain in patients with irritable bowel syndrome.

OBJECTIVE: The influence of the gastrointestinal (GI) microflora in patients with irritable bowel syndrome (IBS) has not been clearly elucidated. This study was undertaken to see if patients with IBS have an imbalance in their normal colonic flora, as some bacterial taxa are more prone to gas production than others. We also wanted to study whether the flora could be altered by exogenous supplementation. In a previous study we have characterized the mucosa-associated lactobacilli in healthy individuals and found some strains with good colonizing ability. Upon colonization, they seemed to reduce gas formation. METHODS: The study comprised 60 patients with IBS and a normal colonoscopy or barium enema. Patients fulfilling the Rome criteria, without a history of malabsorption, and with normal blood tests underwent a sigmoidoscopy with biopsy. They were randomized into two groups, one receiving 400 ml per day of a rose-hip drink containing 5 x 10(7) cfu/ml of Lactobacillus plantarum (DSM 9843) and 0.009 g/ml oat flour, and the other group receiving a plain rose-hip drink, comparable in color, texture, and taste. The administration lasted for 4 wk. The patients recorded their own GI function, starting 2 wk before the study and continuing throughout the study period. Twelve months after the end of the study all patients were asked to complete the same questionnaire regarding their symptomatology as at the start of the study. RESULTS: All patients tolerated the products well. The patients receiving Lb. plantarum had these bacteria on rectal biopsies. There were no major changes of Enterobacteriaceae in either group, before or after the study, but the Enterococci increased in the placebo group and remained unchanged in the test group. Flatulence was rapidly and significantly reduced in the test group compared with the placebo group (number of days with abundant gas production, test group 6.5 before, 3.1 after vs 7.4 before and 5.6 after for the placebo group). Abdominal pain was reduced in both groups. At the 12-month follow-up, patients in the test group maintained a better overall GI function than control patients. There was no difference between the groups regarding bloating. Fifty-nine percent of the test group patients had a continuous intake of fermented products, whereas the corresponding figure for the control patients was 73%. CONCLUSIONS: The results of the study indicate that the administration of Lb. plantarum with known probiotic properties decreased pain and flatulence in patients with IBS. The fiber content of the test solution was minimal and it is unlikely that the fiber content could have had any effect. This type of probiotic therapy warrants further studies in IBS patients.

Abdominal Pain↗

PubMed1999

Genomic relationships between Enterococcus faecium strains from different sources and with different antibiotic resistance profiles evaluated by restriction endonuclease analysis of total chromosomal DNA using EcoRI and PvuII.

Forty-seven Enterococcus faecium strains from different sources were evaluated by restriction endonuclease analysis (REA) of total chromosomal DNA. Strains from chicken, pork, and humans were clearly divided into separate clusters, whereas strains from different countries, strains with different antibiotic resistance profiles, or clinical and healthy-subject strains were not.

Animals↗

PubMed1998

Survival of Lactobacillus plantarum DSM 9843 (299v), and effect on the short-chain fatty acid content of faeces after ingestion of a rose-hip drink with fermented oats.

In a controlled and randomised double-blind study, 26 healthy adult volunteers consumed, for 21 d, 400 ml of a rose-hip drink containing oats (0.7 g/100ml) fermented with Lactobacillus plantarum DSM 9843 (RHL; containing 5 x 10(7) cfu ml(-1)), and 22 volunteers in a second group the same amount of a pure rose-hip drink (RH). Significant increases in the total faecal concentration of carboxylic acids (P < 0.05 after 1 week and P < 0.01 after 3 weeks of intake), acetic acid (P < 0.01 after 3 weeks of intake) and propionic acid (P < 0.01 after 3 weeks of intake and P < 0.05 eight days after intake ceased) were recorded in the RHL group, indicating increased fermentation in the colon. In both groups a significant increase was obtained in the concentration of faecal lactic acid (P < 0.001 after 1 and 3 weeks of intake). No changes were seen in the concentration of faecal butyrate. The numbers of faecal bifidobacteria and lactobacilli increased significantly in both groups after 3 weeks of intake. Sulphite-reducing clostridia rapidly decreased in the group receiving the product with Lb. plantarum DSM 9843 after 1 week of intake, and then also in the pure rose-hip group after 3 weeks of intake. No changes were seen in the numbers of total anaerobes, gram-negative anaerobes or total aerobes during administration. Lb. plantarum DSM 9843 was recovered in faeces from all volunteers in the RHL group. Median amounts were 7.0 (5.0-8.8) log10 cfu g(-1) after one week of intake, and 6.7 (5.0-8.9) log10 cfu g(-1) after 3 weeks, respectively. The strain was still recovered from faeces of five volunteers 8 d after administration ceased (> 4.8 log10 cfu g(-1)). During the period of intake the volunteers in the RHL group experienced a significant increase in stool volume, a significant decrease in flatulence and slightly softer stools. Volunteers in the RH group experienced a slight but significant decrease in stool volume.

Adult↗

PubMed1998

Enterobacteriaceae found in high numbers in fish, minced meat and pasteurised milk or cream and the presence of toxin encoding genes.

Enterobacteriaceae were found in high numbers after storage at 7 degrees C in 6% of consumers packs of pasteurised milk or cream, in 31% of retailed fish and in 100% of retail packs of minced meat. Seventy two fresh-water fishes, 40 packs of minced meat and 430 milk packs were sampled. One hundred and eighty four isolates were randomly picked from Tryptone glucose extract (TGE) agar (30 degrees C for 3d) or Violet red bile glucose (VRBG) agar (37 degrees C for 1d). In minced meat, Serratia liquefaciens, Hafnia alvei, Rahnella aquatilis were frequently encountered. On fish, the most frequently found species were R. aquatilis, and in milk, the dominating species were S. liquefaciens, H. alvei and R. aquatilis. One to three isolates of Citrobacter freundii were found in all three food categories. Using a polymerase chain reaction (PCR) technique, the gene of Escherichia coli heat-labile toxin (lt) was indicated in one fish isolate of R. aquatilis whereas heat-stable toxin genes (s.t.) were indicated in four H. alvei isolates, two originating from fish and two from minced meat. Positive PCR-reaction for vero cytotoxin genes were found in one H. alvei strain originating from fish (vt1), in two S. liquefaciens strains from minced meat (vt2), and in a C. freundii reference strain. One of the st-positive H. alvei strains from meat harboured the eaeA gene involved in the attaching phenotype of enteropathogenic E. coli.

Animals↗

PubMed1998

Identification of clinically important species of Enterococcus within 1 day with randomly amplified polymorphic DNA (RAPD).

The use of randomly amplified polymorphic DNA (RAPD) for rapid, reliable, and easily interpreted identification of enterococci was evaluated. Nineteen type strains of Enterococcus, 12 reference strains, and 114 clinical isolates of Enterococcus were analyzed. Discrimination was obtained between most type strains, the exceptions being Ent. casseliflavus and Ent. flavescens, which had relatively similar RAPD-profiles. Ent. faecalis and Ent. faecium were readily separated, and Ent. gallinarum and Ent. durans could also be identified. Extracts to be used in the polymerase chain reaction (PCR) were prepared directly from agar plate colonies, which made it possible to complete the identification procedure in one day. RAPD was proved to be a fast and reliable method for identification of most Enterococcus spp. of clinical significance.

Enterococcus↗

PubMed1998

Antibiotic-resistant strains of Enterococcus isolated from Swedish and Danish retailed chicken and pork.

Two hundred and seventy-seven Enterococcus isolates representing the predominating enterococcal flora of retailed chicken and pork were identified by phenotypical features, and by random amplified polymorphic DNA. The resistance to nine different antibiotics was determined. Enterococcus faecium was the most frequently occurring species in both Swedish and Danish chicken. Enterococcus faecalis and unidentified groups of Enterococcus dominated in pork. Seventy-three per cent of the Enterococcus isolates from Swedish chicken were resistant to one or more of the tested antibiotics. The corresponding values for Swedish pork, Danish chicken and Danish pork were 9%, 55% and 14%, respectively. Tetracycline resistance was most frequent in isolates from Danish pork and Swedish chicken, while erythromycin resistance was most frequent in Danish chicken. Strains with acquired vancomycin resistance, mainly Ent. faecium, were found only on Danish chicken, except for one isolate from Danish pork. All vancomycin-resistant isolates contained the vanA gene. Vancomycin resistance could be transferred to a vancomycin-sensitive Ent. faecium strain from four of nine tested donor strains.

Animals↗

PubMed1998

The normal Lactobacillus flora of healthy human rectal and oral mucosa.

The Lactobacillus flora of the rectal and oral mucosa was sampled from 42 healthy volunteers. Species identification was carried out by numerically comparing API 50CH fermentation patterns with type strains, using an SJ-similarity cut-off level of 79%. For the largest groups, identity was further confirmed by DNA-DNA hybridizations against the type strain of the species. Seventeen lactobacilli clusters were defined, of which most were found both on rectal and oral mucosa. The largest taxa were Lactobacillus plantarum, Lact. rhamnosus and Lact. paracasei ssp. paracasei, which were isolated from 52%, 26% and 17% of the individuals, respectively. Most isolates were tested for their capacity to adhere to the human colonic cell line HT-29 in the absence and presence of methyl-alpha-D-mannoside. Mannose-sensitive adherence to HT-29 cells was encountered in two-thirds of the Lact. plantarum isolates, but infrequently among isolates of other taxa. The results suggest that Lact. plantarum is a major colonizer of the human gastrointestinal mucosa, and that its capacity to adhere to mannose-containing receptors may be of some ecological importance.

Adult↗

PubMed1997

[Animal husbandry and food handling today. Current food preservation has changed the intestinal flora].

In the modern world, as refrigerated storage has replaced lactic acid fermentation methods of food preservation, we no longer ingest large quantities of live lactobacilli with our food, but relatively large numbers of potentially pathogenic Gram-negative bacteria instead. In the brave new world, antibiotics are used as growth-promoting additives in animal feed in every country but Sweden. The antibiotics used in Europe at low dosages, and exempt from prescription requirements, include macrolides, streptogramins and nitro-imidazoles. There is reason to believe that avoparcin, recently banned in Europe as an antibiotic animal feed additive, has contributed to the occurrence of vancomycin-resistant enterococci in humans. Animal foodstuffs production in Europe and the USA is so intensive that it provides very favourable conditions for the spread of bacteria. Pig, cattle and poultry breeding in Europe are beset by formidable difficulties in the form of Salmonella infections, which constitute not only a hygiene but also a clinical problem. Sweden, the bravest of brave new worlds, faces an increase in the influx of domestic animals and foodstuffs from other countries, and in general less restrictive regulations concerning food production and animal husbandry, but reduced powers of control. Thus, we may expect problems both with pathogens (traditional ones such as Salmonella, and potential ones such as food-spoilage Gram-negative bacteria), and with antibiotic-resistant bacteria in our food-stuffs, to become greater.

Animal Husbandry↗