Here we concentrated in L. johnsonii, a potentially probiotic bacterial species that is of major interest to the pharmaceutical and food industries as it includes several known probiotic strains [25, 28, 29]. We successfully identified and isolated 39 L. johnsonii strains from fecal-bacterial populations of few host species. Strain typing of these isolates together with six additional strains of human origin revealed

AL3818 solubility dmso high levels of genetic variation among the L. johnsonii strains. Both SSR and MLST analyses were found to be effective for typing, providing high-resolution discrimination also among isolates originated in the same animal species. The genetic relationships among the strains inferred by the two analyses were similar, clearly dividing the L. johnsonii strains into three clusters. Selleckchem Temozolomide Each cluster consisted of strains from different diverse hosts, i.e., chickens, humans or mice (Figure 2). These consistent results, obtained by different typing methods, suggest far phylogenetic separation among L. johnsonii isolates presenting host specificity. Such association of particular L. johnsonii strains with the host taxonomy could arise as a result of co-evolution of the host and its GIT microbiota [2, 41–43]. Interestingly, host driven evolution was observed in another

lactobacilli species, L. reuteri[44]. According to the recently suggested “”hologenome theory”" [45], the host and its symbiont microbiota (together defined as the “”holobiont”") are one unit of selection in evolution. Indeed, previous analysis of the L. johnsonii genome showed the absence of genes required for several metabolic pathways [29] emphasizing the high dependence of L. johnsonii on its host and further supports the concept that L. johnsonii and its host are one evolutionary unit of selection. Since chickens, humans and mice are distinct genetic species divided during evolution, L. johnsonii strains associated with them may be evolutionary separated as part of the distinct holobionts. In addition, analysis conducted

on the tRFLP results of 50 host individuals suggest an association of L. intestinalis and E. faecium cluster with host taxonomic 6-phosphogluconolactonase groups (Figure 1), and further support co-evolution of the host and its intestinal bacteria. The E. faecium species cluster was relatively rare in hosts belonging to the Rodentia taxonomic order, and check details alternatively, L. intestinalis was found to be more frequent within that group. These observations may indicate possible competition or a similar function of these two bacteria in the same niche, each within its appropriate microenvironment. Environmental factors, such as diet, are highly important in shaping the host gut’s microbiota composition [4–6, 46]. However, in our study, no correlation was found between the presence of each of the four bacterial species tested and the hosts’ food consumption (herbivore, omnivore and carnivore) or geographical location. Conclusions L.

L. reuteri ATCC 6475 and ATCC PTA 5289 were more adherent then

CF48-3A and ATCC 55730 (ANOVA, p < 0.02). Figure 2 L. reuteri biofilms Repotrectinib concentration were observed by confocal microscopy. Biofilms were cultured in a flow cell supplied with MRS for 48 hours at 37°C in ambient atmosphere. L. reuteri biofilms (green) were stained with acridine orange and observed by confocal microscopy. A single optical section and the stacked optical sections of ATCC 55730 (A and B, respectively) are shown at 630× magnification. These images are representative of 30 microscopic fields obtained in 3 independent experiments. L. reuteri biofilms modulate human TNF production To test the immunomodulatory properties of L. reuteri biofilms, supernatants from the biofilms were added to human monocytoid THP-1 cells in the presence and absence of LPS. LPS was added to the THP-1 cells to stimulate production of pro-inflammatory TNF by THP-1 cells. L. reuteri strains that produced TNF inhibitory factors as planktonic cultures (L. reuteri strains ATCC PTA 6475 and ATCC PTA 5289, 76 and 77%, respectively) (Fig. 3) demonstrated similar abilities to suppress TNF production

when cultured as biofilms (Fig. 4). When TNF inhibitory factors were obtained directly from L. reuteri biofilms grown in 24-well polystyrene plates, ATCC PTA 6475 and ATCC PTA 5289 also inhibited TNF production by YM155 order 60% and 50%, respectively, when compared to the media control (Fig. 4A). Supernatants of L. reuteri ATCC PTA 5289 biofilms cultured in a flow cell inhibited TNF by 73% compared to the media control (Fig. 4B). L. reuteri strains that did not suppress human TNF in planktonic phase (ATCC 55730 and CF48-3A) (Fig. 3) lacked TNF-inhibitory capabilities when supernatants were obtained from the same strains Farnesyltransferase cultured as biofilms (Fig. 4). Surprisingly, supernatants from ATCC 55730 and CF48-3A biofilms did not induce TNF production by THP-1 cells in the absence of LPS (data not shown) as the supernatants from planktonic cultures did (Fig 3). Interestingly,

the ability of probiotic L. reuteri to regulate human TNF production is strain-specific, and strain-specific TNF inhibition was maintained whether L. reuteri strains were cultured as planktonic cells or biofilms. The relative abilities to suppress human TNF in monocytoid cells were directly correlated with relative abilities to aggregate and form biofilms on polystyrene surfaces (Fig. 1A). Figure 3 Modulation of TNF production by L. reuteri is strain-dependent. Cell-free supernatants from stationary phase L. reuteri cultures (planktonic cells) were added to human monocytoid cells in the presence or absence of E. coli-derived LPS (no LPS-black bars, LPS-gray bars). Selleck BIBF1120 Quantitative ELISAs measured the amounts of human TNF produced by THP-1 cells. In the absence of LPS, supernatants from L.

7 kg), and contains a proprietary blend of ingredients called Alka-Myte®. All of the ANS ingredients are allowed by both the U.S. and World anti-doping agencies (i.e., WADA), while Alka-Myte® itself has been granted New Dietary Ingredient (NDI) recognition Olaparib research buy by the Food and Drug Administration (FDA). Given the clearance by WADA and the FDA’s NDI recognition, it surprising that there are no published controlled studies to evaluate the efficacy of

the performance-related claims stated earlier. Therefore, the purpose of this study was to investigate the potential influence of this alkalizing nutrition supplement on previously validated correlates of cross-country skiing performance (i.e., upper body power) [6], as well as cardiorespiratory and blood lactate responses in well-trained competitive Nordic www.selleckchem.com/products/INCB18424.html skiers both before and after a 7-day loading period. Methods Subjects and study design Competitive Nordic skiers from the surrounding area were recruited

to visit the Movement Science/Human Performance Lab on the Montana State University campus on three separate occasions. Competitive skiers familiar with the test protocols used for this study were recruited to help minimize PD-0332991 datasheet changes expected with athletes performing lab-based performance tests for the first time. All subjects were assigned into a treatment or placebo group, but neither the subjects nor the investigators were aware of the either group’s identity until after all data collection was complete (i.e., double-blind placebo-controlled design). Procedures The first visit familiarized

subjects learn more with the testing protocol to be used for subsequent visits. Dependent measures recorded during the second visit (i.e., pre-testing) served to establish a baseline for both placebo and treatment groups. Following a 7-day supplement loading phase, the same tests were administered and dependent measures collected during the third visit (i.e., post-testing) and then compared directly to the pre-test measures. Dependent measures of interest included measures of upper body power (UBP), as well as cardiorespiratory and blood lactate responses to the UBP tests. During the first visit, subjects read and signed an informed consent document approved by the Montana State University Internal Review Board (IRB). Subjects then practiced with the testing protocols to be used during their second (pre-testing) and third (post-testing) visits to the lab. During the latter two visits, subjects completed a submaximal double poling test (i.e., Constant-Power Test), followed by three trials of a maximal intensity 10-sec upper body power test (UBP10), and then finished with a high intensity 60-sec UBP test (UBP60). An outline of the test protocol administered for both pre- and post-testing is outlined in Figure 1. The third lab visit (i.e., post-testing) occurred within 24 hrs of completing the supplement loading phase and repeated all test measures performed during the second lab visit (Figure 1).

Bancroft JD, Stevens A: Theory and practice of histological techniques. 4th edition. London: Churchill Livingstone; 1996. Competing interests The authors have see more declared no competing interests. Authors’ contributions ADP performed all the experiments. KMF carried out the histological analysis. RSD and ASR participated in the collection of immunological data. LLO, CAN and SOP participated in the analysis and interpretation of data. ADP, HCM and SOP participated in the

design of the study. ADP and HCM prepared the manuscript. All authors read and approved the final manuscript.”
“Background Lactococcus lactis – a low-GC Gram-positive model organism, found frequently in both dairy and non-dairy [1] environments, has been extensively studied due to its industrial importance. Major focus of these studies has been on dairy isolates, of which the genomes of three isolates have been sequenced [2–4]. Plant isolates compared to dairy isolates show higher stress-tolerance and have more extensive fermentative abilities [5]. Due to their larger genetic and metabolic repertoire

non-dairy isolates of L. lactis are therefore of interest in dairy food fermentation [6]. Strains used www.selleckchem.com/products/10058-f4.html in dairy starter cultures have presumably evolved from plant strains, where some metabolic capabilities were lost in order to adapt to dairy environments [7]. Recently, the genome of ssp. lactis strain KF147 was fully sequenced [8] and that of strain KF282 was partially sequenced [9]. These two plant L. lactis isolates were reported to possess many genes related to uptake of plant cell-wall degradation products such as arabinose and xylose [9]. Many genes present in these two isolates are new and do not have homologs in the three L. lactis strains IL1403, MG1363 and SK11 of dairy origin [9]. Recently, the genomes of several other L. lactis strains have also been fully

sequenced [10–13]. Furthermore, many L. lactis strains were reported to have plasmids, enriching the genotypic and phenotypic repertoire of this species [3, 14]. L. lactis strains isolated from different niches have been reported to have high genomic sequence divergence Urease [15–17], also at the subspecies level [18]. Their gene content partly reflects their phenotypic properties such as niche adaptation [9, 16, 18]. In general, genomic and phenotypic properties of strains have been studied separately [19, 20], and less frequently possible relations between genes and selleck screening library phenotypes have been studied [21]. Integrative genotype-phenotype matching would facilitate identifying genetic markers relevant for the manifestation of a phenotype. We therefore used an iterative gene selection procedure coined PhenoLink [22] to more accurately determine gene to phenotype relations of 38 L. lactis strains from 3 different subspecies: ssp. lactis, ssp. cremoris and ssp. hordniae (see Table 1). This allowed identifying novel gene-phenotype relations as well as confirming previously reported relations.

10. Rocha HM, Wheeler BEJ: The water balance as an important factor in basidiocarp production by Crinipellis perniciosa , the causal fungus of cocoa witches’ broom. Proc 8th Internat. Cocoa Res. Conf. 1981. Cartagena, Columbia: Cocoa Producers Alliance 1982, 381–386. 11. Rocha HM, Wheeler BEJ: Factors influencing the production of basidiocarps and the deposition and germination of basidiospores of Crinipellis perniciosa , the causal agent of witches’ broom disease on cocoa ( Theobroma cacao ).

Plant Pathol 1985, 34:319–328.CrossRef 12. Stahel G: Contribution to the knowledge of witch broom disease. Surinam Department of Agriculture. Bull. 39. Tropical Agriculture GW786034 purchase 1919, IX:167–176. 13. Purdy LH, Trese AT, Aragundi JA: Proof of pathogenicity of Crinipellis perniciosa to Theobroma cacao by using basidiospores produced in in vitro cultures. Theobroma (Brazil) 1983, 13:157–163. 14. Purdy LH, Dickstein ER: Basidiocarp development on mycelial mats of Crinipellis perniciosa.

Plant Dis 1990, 74:493–496.CrossRef 15. Niella G, Resende ML, Castro HA, de Carvalho GA, Silva LHCP: Aperfeiçoamento da metodologia de produção artificial de basidiocarpos de Crinipellis perniciosa. Fitop Brasileira 1999, 24:523–527. 16. Macagnan D, Romeiro RS, Souza J, Pomella AWV: Isolation of actinomycetes and endospore-forming bacteria from the cacao https://www.selleckchem.com/products/arn-509.html pod surface and their activity against the witches’ broom and black pod pathogens. Phytoparasitica 2006, 34:122–132.CrossRef 17. Kues U, Liu Y: Fruiting body production in basidiomycetes. Appl Microbiol Biotechnol 2000, 54:141–152.PubMedCrossRef 18. Massicotte HB, Melville LH, Peterson RL: Building a basidiocarp: a case study of Laccaria spp. fruitbodies in the extraradical mycelium of Pinus ectomycorrhizas. Mycologist 2005, 19:141–149.CrossRef 19. Kues U: Life history and developmental processes in the basidiomycete Coprinus cinereus. Microbiol Mol Biol Rev 2000, 64:316–353.PubMedCrossRef Arachidonate 15-lipoxygenase 20. Almeida LC, Bastos CN, Ferreira NP: Produção de basidiocarpos de Crinipellis perniciosa

em dois sistemas de cultivo de cacaueiro. Fitopat Brasileira 1995, 20:60–64. 21. Evans HC, Bastos CN: Basidiospore germination as a means of assessing resistance to Crinipellis perniciosa (Witches’ broom disease) in cocoa cultivars. Trans Br Mycol Soc 1980, 89:525–536.CrossRef 22. Evans HC: Witches’ broom disease – A case study. Cocoa Growers Bulletin 1981, 32:5–19. 23. Delgado JC, Cook AA: Nuclear condition of basidia, basidiospores, and mycelium of Marasmius perniciosus. Canad J Blasticidin S molecular weight Botany 1976, 54:66–72.CrossRef 24. Muse RB, Collin HA, Isaac S, Hardwick K: Effects of the fungus Crinipellis perniciosa , causal agent of witches’ broom disease, on cell and tissue cultures of cocoa ( Theobroma cacao L.). Plant Pathol 1996, 45:145–154.CrossRef 25. Kilaru A, Hasenstein KH: Development and pathogenicity of the fungus Crinipellis perniciosa on interaction with cacao leaves. Phytopathology 2005, 95:101–107.

Apart from the listed metabolites used for mass spectrometry analyses, the Streptomyces strains produced further compounds which resulted in the following SNS-032 solubility dmso numbers of peaks: AcM9, five; AcM11, nine; AcM20, eight; AcM29, eleven; AcM30, six. Table 2 Chemical diversity of Norway spruce mycorrhiza associated Streptomyces Strain Medium Substance based on UV–vis Measured [M + H]+ Theoretical [M + H]+ Confirmed AcM9 SGG Unknown 180,1 n. a. n. a. AcM11 OM Cycloheximide 282,1 282,169825 Yes AcM11 OM Actiphenol 276,1 276,123525 Yes AcM11 OM Acta 2930 B1 1007,5

1008,507825 No AcM11 OM Ferulic acid 195 195,065735 Yes AcM11 OM Unknown 292 n. a. n. a. AcM11 OM Unknown 407 n. a. n. a. AcM11 OM Unknown 387 n. a. n. a. AcM20 SGG Unknown 180,1 n. a. n. a. AcM20 OM Unknown 298 n. a. n. a. AcM29 SGG Desferrioxamine B 561,5 561,691825 Yes AcM29 SGG Unknown 180 n. a. n. a. AcM29 SGG Unknown 340 n. a. n. a. AcM29 SGG Unknown 523 n. a. n. a. AcM29 SGG Unknown 482 n. a. n. a. AcM29 OM Ferulic acid 195,1 195,065735 Yes AcM29 OM Unknown 298,3 n. a. n. a. AcM29 OM Unknown 477,3 n. a. n. a. AcM29 OM Unknown 151,1 n. a. n. a. AcM29 OM Unknown 217,2 n. a. n. a. AcM30 SGG Anthranilic acid 138 138,054825 Yes AcM30 SGG Silvalactam 637,6 637,427825 Yes The metabolite spectra of five selected buy SU5416 Streptomyces strains were investigated. The bacteria were grown on oat meal (OM) and starch-glucose-glycerol (SGG) media. The substances

were identified based on their UV–vis spectra and on their molecular mass, determined by ESI-LC-MS. Obeticholic Acid The term “Confirmed” refers to verification of compound identity by comparison with the purified substance. Apart from the listed metabolites the Streptomyces strains produced

the following numbers of other peaks: AcM9, five; AcM11, nine; AcM20, eight; AcM29, eleven; AcM30, six. Figure 3 The strong antagonist of fungi, Streptomyces AcM11, produces several antifungal metabolites. Total ion chromatogram (a) and UV/Vis spectra of the peaks A-D (b-e), extracted from AcM11 oat meal suspension culture. The identities of the metabolites were determined based on their retention times, UV–vis spectra, mass spectrometry, and comparisons to reference compounds. Varying sensitivity of Heterobasidion spp. to cycloheximide is reflected in bioassays with the cycloheximide Lonafarnib cost producer Streptomyces sp. AcM11 The plant pathogenic fungus H. abietinum was more strongly inhibited by AcM11 than H. annosum in co-culture. The identification of cycloheximide as an AcM11 produced substance enabled us to assess the tolerance of each fungus to cycloheximide. Cycloheximide concentration in the suspension culture medium was estimated as 10.2 nmol x ml-1 (10.2 μM). Based on this finding, a concentration series of cycloheximide was applied. H. abietinum was inhibited by 10-fold lower concentrations of cycloheximide than H. annosum (Additional file 4).

J Bacteriol 1998, 180:5567–5573.PubMed 62. Palma M, Zurita J, Ferreras JA, Worgall S, Larone DH, Shi L, Campagne F, Quadri LE: Pseudomonas aeruginosa SoxR does not conform to the archetypal paradigm for SoxR-dependent regulation of the bacterial oxidative stress AP24534 ic50 adaptive response. Infect Immun 2005, CP673451 in vivo 73:2958–2966.PubMedCrossRef Competing interests The authors declare that they have no competing interests. Authors’ contributions LQ conceived the study. ET, SC, PM, UE and SA carried out the experiments. LQ, ET, SC, and DC analyzed results and drafted the manuscript. All authors read and approved the final manuscript.”
“Background

Concrete corrosion of wastewater collection systems is a significant cause of deterioration and premature failure. In the U.S., costs associated with maintaining an estimated 800,000 miles of wastewater collection infrastructure are approximately $4.5 billion per year [1]. Many systems may be beyond their design life and must be replaced because they cannot be rehabilitated [2]. Failure to adequately address the deteriorating infrastructure networks threatens our environment, public health, and safety. In wastewater collection systems microbial-induced concrete corrosion (MICC) may occur in areas under higher concentrations of hydrogen sulfide (H2S) [3–5]. The primary source of sulfur is sulfate (SO4 2-) which can

be reduced by sulfate-reducing bacteria (SRB) to hydrogen sulfide (H2S) under anaerobic conditions. H2S is transferred across the air-water interface to the sewer atmosphere where chemoautotrophic see more bacteria on the pipe surface, including sulfide-oxidizing bacteria (SOB), convert the H2S to biogenic sulfuric acid (H2SO4). Biogenic sulfuric acid (H2SO4) can be generated by various microbial LY294002 species [6–9]. While many of the microorganisms and general mechanism involved in MICC has been known for decades, and recent studies using molecular-based approaches have more accurately described the microbial ecology of these engineered systems [6, 8, 9], a better understanding

of the metabolic processes and functional capabilities is needed to develop new approaches to mitigate MICC and its associated effects. The objective of this study was to characterize the microbial community of concrete wastewater biofilms and their functional capability based on molecular analyses of metagenome libraries and to compare it with 16S rRNA gene sequences from previously generated clone libraries [7–11]. Specifically, we sampled biofilms from two sections of a severely corroded concrete wastewater pipe to obtain a better understanding of microbial community colonization processes and mechanisms of concrete deterioration. To our knowledge this is the first published report utilizing metagenomics to elucidate microbial community functional capabilities involved in MICC in wastewater collection systems.

IDSA guidelines Vadimezan represent an important reference for the management of intra-abdominal infections. WSES guidelines represent a further contribution on this debated topic TSA HDAC by specialists worldwide. The recommendations are formulated and graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) hierarchy of evidence [2, 3] summarized in Table 1. Table 1 Grading of recommendations from Guyatt and colleagues [2] Grade of recommendation Clarity of risk/benefit

Quality of supporting evidence Implications 1A       Strong recommendation, high-quality evidence Benefits clearly outweigh risk and burdens, or vice versa RCTs without important limitations or overwhelming evidence from observational studies Strong recommendation, can apply to most patients in most circumstances without reservation 1B       Strong recommendation, moderate-quality evidence Benefits clearly outweigh risk and burdens, or vice versa RCTs with important limitations (inconsistent results, methodological flaws, indirect or imprecise) or exceptionally strong evidence from observational studies Strong selleck chemical recommendation, can apply to most patients in most circumstances without reservation 1C       Strong recommendation, low-quality or very low-quality evidence Benefits clearly outweigh risk and burdens, or vice versa Observational studies or case series Strong recommendation but may change when higher quality

evidence becomes available 2A       Weak recommendation, high-quality evidence Benefits closely

balanced with risks and burden RCTs without important limitations or overwhelming evidence from observational studies Weak recommendation, best action may differ depending on circumstances or patient or societal values 2B       Weak recommendation, moderate-quality evidence Benefits closely balanced with risks and burden RCTs with important limitations (inconsistent results, methodological flaws, indirect or imprecise) or exceptionally strong evidence from observational studies Weak recommendation, best action may differ depending on circumstances or patient or societal values 2C       Weak recommendation, Low-quality or very low-quality evidence Uncertainty in the estimates of benefits, risks, and burden; benefits, risk and burden may be closely balanced Observational studies or Amrubicin case series Very weak recommendation; other alternatives may be equally reasonable Principles of sepsis management Severe sepsis and septic shock are the leading causes of multiple organ failure and mortality in noncoronary intensive care units (ICUs) [4, 5]. Unfortunately, despite tremendous basic and clinical research efforts, mortality from septic shock remains unchanged at greater than 50%. In an effort to improve sepsis-related mortality, several organizations have outlined evidence-based guidelines (EBGs) for the management of severe sepsis and septic shock [6]. Physicians have known about the existence of sepsis for centuries.

Plasmid profiles The plasmid profiles of four transconjugants from each cross were visualized on agarose gels according to the protocol described by Hynes and McGregor [26]. DNA isolation and manipulation Plasmid DNA was isolated using the High Pure Plasmid Isolation Kit (Roche) according to the manufacturer’s

instructions. Restriction and ligation reactions were performed under the conditions selleck specified by the enzyme manufacturer (Fermentas). PCR was performed using Platinum High Fidelity Taq Platinum Polymerase or ThermalAce™ DNA Polymerase (Invitrogen). PCR products were cloned using the TOPO TA Cloning Kit (Invitrogen). Plasmid incompatibility The incompatibility properties of the constructs were determined as described in Ramírez-Romero et al. [7]. Plasmid replication in R. etli To determine the replication capabilities of the pDOP derivatives in R. etli, the plasmids were introduced into CFNX107 by conjugation. The plasmid profiles of at least four transconjugants from each cross were analyzed. A recombinant plasmid was considered capable of replicating in R. etli if the plasmid profiles of the transconjugants showed a new band of the expected size. Plasmid copy-number determination

The plasmid copy numbers of the CFNX107 transconjugants containing pDOP derivatives were evaluated as follows: the total DNA of each transconjugant was isolated, digested with HindIII endonuclease, resolved in a 1% agarose gel and transferred to Hybond-N+ membranes (Amersham). The blot was then simultaneously hybridized with an Ω- spectinomycin cassette Reverse transcriptase located within the recA gene (chromosome-encoded) and with a fragment of pDOP; both probes were of the same size and GC selleckchem content. The hybridization signals were quantified with a PhosphorImager SI (Molecular Dynamics). The plasmid copy-number was calculated from the ratio of the integrated hybridization signal of the recombinant plasmid and the integrated hybridization signal of the chromosome. Bioinformatics APR-246 solubility dmso Alignments were performed with Clustal-W [27] at the WWW service of the European Bioinformatics Institute http://​www2.​ebi.​ac.​uk/​clustalw. Protein secondary structure predictions were made with PSIPRED [28] at the WWW service of

the Bioinformatics Group, UCL Department Of Computer Science http://​bioinf.​cs.​ucl.​ac.​uk/​psipred/​. The DNA duplex helical stability profile was calculated using WEB-THERMODYN: sequence analysis software for profiling DNA helical stability http://​www.​gsa.​buffalo.​edu/​dna/​dk/​WEBTHERMODYN/​[29]. Results The oriV of p42d is located within the repC coding sequence The basic replicon of Rhizobium etli p42d, defined as the smallest DNA region that contains all of the elements required to replicate with the same stability and plasmid copy-number as the parental plasmid, consists of the complete repABC operon plus 500 bp downstream of the repC stop codon (inc-beta region, containing parS) and 86 bp upstream of the repA initiation codon [8] (Figure 1).

This is in line with other large cohort studies which reported either a gradual increase or BVD-523 chemical structure decrease in risk ratios for higher physical activity categories [12, 14]. In this study, physical activity was not significantly associated with fall risk. Three other cohort studies reported an increased fall risk in men [12] and a decreased fall risk in women [14] or in persons living in a residential care setting [13] in higher physical activity categories as compared with the lowest category. Perhaps lack of an association in our study is

due to an interaction with sex. However, the interaction term for physical activity by sex was not significant (p = 0.89). A second explanation may be that in our study, participants with high levels of physical activity were underrepresented causing an underestimation of the actual relationship. However, our sample is representative for the community-dwelling older population Staurosporine purchase in the Netherlands. Third, these three studies and the current study differed in population (men [12] vs women [14] vs residential care setting [13]), physical activity measures (validated questionnaires [12] vs operational definitions

[14]), and outcome measures (4-month fall risk [12] vs proportion fallers [14]). It is likely that the contrasting findings are explained by differences in population and methodology. The association between physical activity and recurrent falling check details has been studied only once before. A study among persons (70+ years) living in a residential care setting showed that the risk of recurrent falling decreased at higher levels of physical cAMP activity [13]. Our findings in community-dwelling older persons are in line with this study: an increase of 100 units led to a 4% lower risk of recurrent falling. One hundred units equal 30 min per day of walking, 20 in of swimming, or 40 min

of billiards. Thus, if all older persons increase their physical activity level with 100 units, 4% may be prevented to become recurrent fallers. In addition, given the beneficial effects of physical activity on other health outcomes, it is important to observe that, other than expected in the literature, highly active persons do not have an increased risk of falling. Clinical trials are necessary to test whether increasing physical activity leads to a decrease in falls. Two recently published systematic reviews showed that multiple component exercise programs did reduce the fall risk in community-dwelling older persons [34, 35]. Increasing daily physical activity may be an important component of these exercise programs. It has been suggested that in this type of study adjustment should be made for baseline mobility [9]. Like physical performance and functional limitations, mobility is a measure of physical functioning. In the current study, physical functioning did not modify the relationship between physical activity and (recurrent) falling.