reuteri, affects on streptococcus mutants, colonization of the te

reuteri, affects on streptococcus mutants, colonization of the teeth surface by lactobacilli Less carries after the ingestion of living or oral vaccination with heat-killed lactobacilli Enhanced nutrient value Chr. Hansen (Horsholm, Denmark) Snow Brand Milk Products Co., Ltd (Tokyo, Japan) Institut Rosell (Montreal, Canada) Rhodia, Inc. (Madison, WI) Nebraska Cultures, ERK inhibitor libraries Inc. (Lincoln, NE) L. casei DN014001 (Immunitas) Danone Le Plessis- Robinson (Paris, France) Urex Biotech Inc. (London, Ontario, Canada) L. johnsonii La1 (same as Lj1) Nestlé (Lausanne, Switzerland) Probi AB (Lund, Sweden) L. reuteri SD2112

(same as MM2) Valio Dairy (Helsinki, Finland) Essum AB (Umeå, Sweden) University College (Cork, Ireland) Morinaga Milk Industry Co., Ltd (Zama-City, Japan) L. delbrueckii subsp. bulgaricus 2038 Meiji Milk Products (Tokyo, Japan) Lacteol Laboratory (Houdan, France) Arla Dairy (Stockholm, Sweden) Biocodex Inc. (Seattle, WA) New Zealand Dairy Board The intestinal microbial community is a complex ecosystem, and introducing new organisms into this highly competitive environment is difficult. Thus, organisms that can produce a product that inhibits the growth of existing organisms have a characteristic advantage. The ability of probiotics to establish in the GI

tract is enhanced selleck screening library by their ability to eliminate competitors. Some antimicrobials with producer organisms are enlisted in Table 3. In different studies on humans and animals, beneficial microorganisms are used to improve the colonization resistance on body surfaces, such as GI, the urogenital, and the respiratory tract. Bifidobacteria produce acetic and lactic acids in a molar ratio of 3 : 2 (Desjardins

& Roy, 1990). Lactobacillus acidophilus and Lactobacillus casei produce lactic acid as the main end product of fermentation. In addition to lactic and acetic acids, probiotic organisms produce other acids, such as hippuric and citric acid. Lactic acid bacteria also produce hydrogen peroxide, diacetyl, and bacteriocin as antimicrobial substances. These inhibitory substances create antagonistic environments for foodborne pathogens and spoilage organisms. Yoghurt bacteria are reported to produce bacteriocin against probiotic bacteria and vice versa (Dave & Shah, 1997). Wide-spectrum antibiotic Acidolin, Acidophilin, Histidine ammonia-lyase Lactocidin, Lactocin B L. delbrueckii ssp. bulgaricus L. sake L45, L. sake Lb706 Nisin, Lactostrepsin, Lactocin, Lacticin Pediococcus pentosaceous, P. acidilactis Enterococcus faecium DPC1146 Goldin & Gorbach (1980) reported that the introduction of L. acidophilus into the diet lowers the incidence of chemically induced colon tumors in rats. Later, the same authors also suggested that diet and antibiotics can lower the generation of carcinogens in the colon and reduce chemically induced tumors (Goldin & Gorbach, 1984). These effects appear to be mediated through the intestinal microbial communities.

To investigate the effect of pyrroloquinoline quinone (PQQ) (Mits

To investigate the effect of pyrroloquinoline quinone (PQQ) (Mitsubishi Gas Chemical Company Inc., Tokyo, Japan) for the protein refolding, PQQ at the concentration of 70 μM was added to both the refolding and the dialysis buffers. The reaction mixture (1 mL) contained 2 mM K2S4O6, 200 mM K2SO4, 100 mM β-alanine nitrate buffer (pH 3.0), and 50 μL of enzyme solution in thin glass tubes.

In the case of purified enzyme, the protein concentration of the solution was 0.1 mg mL−1. The reaction was initiated by adding 50 μL of enzyme solution at 30 °C. After incubating for the appropriate reaction period, the reaction tubes were immediately placed in cold ethanol (−20 °C) with shaking HIF inhibitor for 2 min, followed by boiling for 90 s to stop the reaction. Because elemental sulfur was produced by the reaction, the samples were centrifuged

at 10 000 g for 1 min to remove the byproduct (S0). The enzyme activity was measured by determining the concentration of tetrathionate remaining in the supernatant by cyanolysis (Nor & Tabatabai, 1975). One unit (U) of the activity was defined as the amount of enzyme required for the hydrolysis of 1 μmol tetrathionate min−1. Quinoproteins were detected by staining with nitroblue tetrazolium (NBT) (Paz et al., 1991; TGF-beta inhibitor Rzhepishevska et al., 2007). The NBT solution contained 0.24 mM NBT in 2 M potassium glycinate buffer (pH 10). Protein samples were blotted onto a nitrocellulose membrane and dried at room temperature. The membrane was immersed in the NBT solution for 45 min in the dark, and subsequently dipped into 0.1 M sodium borate (pH 10). Quinoproteins could be specifically detected as purple-blue spots due to NBT reduction to formazan. PQQ (Mitsubishi Gas Chemical Company Inc.), used as a positive control and blotted onto a nitrocellulose membrane, was treated as described above. The plasmid pET4TH encoding the recombinant 4THase without the signal peptide was introduced 4��8C into

E. coli BL21 Star™(DE3). Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the soluble and insoluble fractions revealed the presence of a recombinant protein in the insoluble fraction (Fig. 1, lane 2), suggesting that the protein was synthesized in inclusion bodies. Some proteins derived from host cells were removed by washing the inclusion bodies with the solution containing Triton X-100. As shown in Fig. 1, the recombinant protein prepared from the washed inclusion bodies exhibited a single main band on SDS-PAGE (Fig. 1, lane 3). The refolding experiments of recombinant Af-Tth synthesized in inclusion bodies of E. coli were carried out to obtain the recombinant Af-Tth in the active form. The protein solubilized from inclusion bodies with 6 M guanidine hydrochloride solution containing 10 mM dithiothreitol was used for the refolding experiments. Initially, the effect of pH on the refolding of recombinant Af-Tth was evaluated.

Gilead funded part of this work through an unrestricted education

Gilead funded part of this work through an unrestricted educational grant via their United Kingdom and Ireland Fellowship Programme. The Nintedanib funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. JL and YC received funding for HIV testing from Gilead. JC, SE and FB

have received funding from various pharmaceutical companies to attend conferences and/or been paid to lecture at educational meetings. JW, SM and RT have no conflicts of interest to declare. “
“HIV-associated lipodystrophy is a disorder of fat metabolism that occurs in patients with HIV infection. It can cause metabolic derangements and negative self-perceptions of body image, and result in noncompliance with highly active antiretroviral therapy (HAART). Growth hormone (GH) axis drugs have been evaluated check details for treatment of this disorder, but no systematic review has been conducted previously. The aim of the review was to compare the effects of GH axis drugs vs. placebo in changing visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and lean body mass (LBM) in patients with HIV-associated lipodystrophy. We searched MEDLINE (1996–2009), CENTRAL (Issue 4, 2009), Web of Science, Summons,

Google Scholar, the Food and Drug Administration (FDA) website, and from 13 October 2009 to 7 June 2010. We excluded newspaper articles and book reviews from the Summons search; this was the only search limitation applied. We also manually reviewed references of included articles. Inclusion criteria were as follows: randomized placebo-controlled trial (RCT); study participants with HIV-associated lipodystrophy; intervention

17-DMAG (Alvespimycin) HCl consisting of GH, growth hormone releasing hormone (GHRH), tesamorelin or insulin-like growth factor-1 (IGF-1); study including at least one primary outcome of interest: change in VAT, SAT or LBM. Two independent reviewers extracted data and assessed study quality using a standardized form. The authors of one study were contacted for missing information. The main effect was calculated as a summary of the mean differences in VAT, SAT and LBM between the intervention and placebo groups in the included studies. Subgroup analyses were performed to assess different GH axis drug classes. Ten RCTs including 1511 patients were included in the review. All had a low risk of bias and passed the test of heterogeneity for each primary outcome. Compared with placebo, GH axis treatments decreased VAT [weighted mean difference (WMD) –25.20 cm2; 95% confidence interval (CI) –32.18 to –18.22 cm2; P<0.001] and increased LBM (WMD 1.31 kg; 95% CI 1.00 to 1.61 kg; P<0.001], but had no significant effect on SAT mass (WMD –3.94 cm2; 95% CI –10.88 to 3.00 cm2; P=0.27]. Subgroup analyses showed that GH had the most significant effects on VAT and SAT, but none on LBM. The drugs were well tolerated but statistically significant side effects included arthralgias and oedema.

The major source of NADH in R erythropolis is the carbon metabol

The major source of NADH in R. erythropolis is the carbon metabolism. Ethanol yields more NADH during this metabolism than glucose and glycerol. The additional NADH enables the cell to increase the flux (or desulfurizing rate) of the 4S pathway, which eventually helps it to increase growth. Extending this, we argue that a carbon source that provides more NADH

is likely to enhance both the growth and the desulfurizing rates of R. erythropolis. As our model predicted some experimental observations successfully, we examined the suitability of additional carbon sources for desulfurizing activity. We studied citrate, ethanol, fructose, gluconate, glucose, glycerol, glutamate, and lactate as possible sole carbon sources. We computed fluxes for each sole source separately with an Erlotinib concentration uptake rate of 20 mg g−1 dcw h−1.

Figure 4 shows the results of our eight simulation runs. The desulfurization and growth rates relative to those of ethanol decrease in the following order: ethanol (0.18 mmol HBP g−1 dcw h−1 as 100% and 1.39 h−1 as 100%)>lactate (67%)>citrate (48%)>glutamate (44%)>glucose=fructose (43%)>glycerol (42%)>gluconate (40%). However, as our model is reduced and has limited scope, this prediction is only qualitative in nature. An experimental verification of this prediction is clearly beyond the scope of this work. As a natural goal of any MK0683 in silico model, our intention is simply to offer a new hypothesis that experimental researchers can verify. Our reconstructed stoichiometric model for sulfur metabolism in R. erythropolis successfully predicted cell growth and several known/unknown phenotypes. Our analysis shows that NADH plays a critical role in desulfurization activity. Any changes in medium design or genetic manipulations that increase NADH regeneration and supply within the cellular metabolism are likely to enhance desulfurization activity. We are in the process of developing a full genome-scale model that can account for host functions other than just sulfur and central 2-hydroxyphytanoyl-CoA lyase metabolism. Table S1. Metabolite and reaction content of the model. Please note: Wiley-Blackwell is not responsible for the

content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. “
“Fusarium species can produce mycotoxins, which can contaminate cereal-based food producing adverse effects for human and animal health. In recent years, the importance of Fusarium poae has increased within the Fusarium head blight complex. Fusarium poae is known to produce trichothecenes, especially nivalenol, a potent mycotoxin able to cause a variety of toxic effects. In this study, a specific primer pair was designed based on the tri7 gene to detect potential nivalenol-producing F. poae isolates. A total of 125 F. poae, four F. cerealis, two F. culmorum, one F. langsethiae, one F. sporotrichioides and seven F.

Pectate lyases, amylases and xylanases are examples of probably t

Pectate lyases, amylases and xylanases are examples of probably the most ubiquitous hydrolytic enzymes secreted by Bacillus species (Priest, 1977; Tjalsma et al., 2004). Bacillus subtilis secretes at least seven different exoproteases including two major proteases (subtilisin and neutral metalloprotease E) and five minor proteases (bacillopeptidase F, Mpr, Epr Npr and Vpr) (Pero & Sloma, 1993, Table S1). These exoproteases digest proteins present in the environment, a response that is induced by low levels of available nitrogen (Hata et al., 2001).

Wild-type strains of B. subtilis that are deficient in the production of these extracellular proteolytic activities are also unable to swarm or form biofilms (Pero & Sloma, 1993; Connelly et al., 2004). The other active EPS category includes proteins click here that interact with substrates of different chemical nature that can be secreted during nutrient deprivation. Bacillus subtilis strains secrete many proteins involved in the degradation of a variety of molecules such as lipids, glutathione, phytic acid and extracellular nucleic acids to cope with conditions of low nitrogen (Priest, 1977; Tjalsma et al., 2004). Among the proteins active in

the formation of the exopolymeric matrix, special attention needs to be drawn to the recently identified selleck chemicals TasA protein. This protein is encoded by tasA, a gene expressed at the onset of sporulation in B. subtilis (Branda et al., 2006). TasA is required for the structural integrity of the matrix as well as biofilm development: it has been proposed that TasA forms amyloid fibers that bind cells together in the biofilm (Romero et al., 2010). TasA localization within the exopolymeric matrix is dependent on a functional yqxM gene, but the

role of YqxM in biofilm development is still unknown, another area that requires further investigation (Branda et al., 2006). The presence and role of extracellular DNA in B. subtilis strains is another topic that is poorly understood. In the close relative Bacillus cereus, biofilm formation requires DNA as part of the extracellular polymeric matrix (Vilain et al., 2009). DNA in biofilms may be involved in events of recombination that take place in natural environments (Spoering & Gilmore, 2006). Further studies on extracellular Mannose-binding protein-associated serine protease DNA in B. subtilis biofilms will help elucidate its role in natural environments. Microorganisms in nature are subject to sudden changes in the environmental conditions such as nutrient deprivation, desiccation, osmotic stress, action of antibiotic molecules released by other microorganisms, UV radiation and temperature variations. Bacillus subtilis can survive these environmental fluctuations, which are typical for soils, through several defense mechanisms (Setlow, 1992). Although spore formation is the main mechanism for long-term survival for B.

mompa is a vacuole-mediated process The basidiomycete fungus Hel

mompa is a vacuole-mediated process. The basidiomycete fungus Helicobasidium mompa Tanaka causes severe violet root rot diseases of fruit trees (Ito, 1949). Previous research has attempted to develop a biological control mechanism (virocontrol) to protect against violet root rot, that is, a virocontrol agent based on a hypovirulent mycovirus is used to reduce the pathogenicity of the fungal pathogen (Ghabrial & Suzuki, 2009). However, in H. mompa, the heterogenic incompatibility system (i.e. the system

that rejects genetically incompatible hyphae) prevents mycoviruses from spreading among different fungal strains (Esser, 2006). For successful introduction of mycoviruses into a given fungal strain, it is therefore important to understand

the mechanism responsible for heterogenic selleck kinase inhibitor incompatibility system in H. mompa. When an individual mycelium encounters mycelia belonging to the same species, the mycelia attract each other and try to fuse by anastomosis; each hypha is capable of recognizing both self and nonself hyphae (Esser & Blaich, 1973; Esser, 2006). When the hyphal cell recognizes nonself hyphae, programmed cell death (PCD) is triggered to protect the hypha from invasion by potentially deleterious organisms or cell structures such as mycoviruses see more and malignant mitochondria (Caten, 1972). All types of cells undergo PCD, a process which is mediated by an intracellular program found in metazoans, plants, and fungi (Ranganath & Nagashree, 2001; Ramsdale, 2008). PCD is an integral control mechanism involved in normal homeostasis and development. In addition, the ability of PCD to eliminate unwanted cells seems to be an evolved defense mechanism against other organisms (Mittler & Lam, 1996). Given the importance of PCD, researchers have studied these phenomena. They have discovered a range of mechanisms, including apoptotic type I cell

Rucaparib cost death, autophagic type II cell death, and necrotic type III cell death (Zakeri et al., 1995). The PCD mechanism varies greatly among tissue types and taxonomic groups. PCD in filamentous fungi has been reported during basidiocarp development (Lu, 2006) and as a result of heterogenic incompatibility (Saupe, 2000; Glass & Kaneko, 2003; Esser, 2006). Typical apoptotic features, such as cytoplasmic shrinkage and DNA fragmentation by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL), have been observed during basidiocarp development; because they occurred during meiosis, they were confined to the basidial cells (Lu et al., 2003). Heterogenic incompatibility involves restrictions not only in mating competence but also in heterokaryon formation in vegetative cells; the incompatibility is controlled by the genes MAT (mating type), het (heterokaryon incompatibility), and vic (vegetative incompatibility) (Saupe, 2000; Esser, 2006).

0 Hz and a resolution of 512 × 512 pixels Mycobacterium smegmati

0 Hz and a resolution of 512 × 512 pixels. Mycobacterium smegmatis culture was grown for 14–16 h at 37 °C and the culture was either treated with 0.8 mM of decanol for 2 h or left untreated. Cells were harvested, washed with Bortezomib phosphate-buffered saline (PBS) and treated with 4 μg mL−1 acridine orange for 15 min. Thereafter, cells were washed with PBS and treated with 4 μg mL−1 ethidium bromide. Cells were viewed under a fluorescence microscope. Each well of a six-well polysterene Petri dish of 9.6 cm2 was poured with 2 mL of Middlebrook 7H9 medium. Each well was inoculated with M. smegmatis mc2155 culture grown for 48 h (106 CFU mL−1) and

incubated at 37 °C for 4 days to allow biofilm formation. Thereafter, planktonic cells were pipetted out carefully and the adhered biofilm was stained with 4 μg mL−1 of acridine orange in PBS for 15 min and viewed under a fluorescence microscope. For crystal violet (CV) assay, 200 μL of a saturated culture of M. smegmatis was added to each well of a 96-well plate and incubated at 37 °C 48 h. Thereafter, culture broths from the wells were discarded.

Wells were washed with mQ water and to each well, 200 μL of 0.4% CV was added. CV was allowed to adsorb to the biofilm components for 15 min at room temperature. Next, each well was washed with mQ water Selleckchem HSP inhibitor to remove any unadsorbed CV from the wells. Then, 33% acetic acid was added to dissolve the CV adsorbed to the biofilm and the amount was measured by determining its absorbance in a microplate reader at 630 nm (Molecular Devices, Sunnyvale, CA). Long-chain fatty alcohols are long known to exhibit antimicrobial activity. To test the activity of long-chain fatty alcohols against mycobacteria, primarily the antimycobacterial activity of alcohols containing 5–13 carbons

in their chain were assessed by the disc diffusion method in an agar plate against M. smegmatis as described. The radius of zone of inhibition increased almost linearly with the number of carbon atoms in the chain from 1-hexanol to 1-decanol (Fig. 1a). Alkanols with more than 10 carbon atoms showed a drastic reduction in activity (Fig. 1a). In contrast, long-chain hydrocarbons starting from n-hexane to n-decane showed no inhibitory action against M. smegmatis. Alcohols with a different number of carbon molecules starting from pentanol to tridecanol show not only a wide range of molecular weight but also a variable degree of polarity. The ability to diffuse in the agar plate depends strongly on their polarity, viscosity and other physical properties, and thus can influence its antimicrobial activity in a plate assay. To overcome solubility and diffusion problems of different alcohols with the agar diffusion method the alcohols were solubilized in a universal solvent such as DMSO (70%) and subjected to determination of MIC by the BDS method. Table 1 summarizes the antimicrobial activities of long-chain fatty alcohols on M. smegmatis mc2155 and M.

These environmental factors were the only triggers in the case of

These environmental factors were the only triggers in the case of Burkholderia and nifH genes while, in the case of Alphaproteobacteria, their influence was generally overcome

by the biogeographical effect, and this also explains why samples of Burkholderia and nifH cluster more tightly than Alphaproteobacteria based on sampling location. Our results suggest that these bacterial groups are differentially shaped by geography and habitat and that the Alphaproteobacteria in Lobaria are maintained across space and evolve across time. As stated above, Alphaproteobacteria are the dominant lichen-associated bacterial group, whereas other taxa, including Burkholderia, are present at lower abundances. Our results demonstrate a differential effect of habitat and geography on the composition of these groups of the lichen-associated bacteria. The this website structure of Alphaproteobacteria correlated well with geography, whereas this effect could not be observed in Burkholderia and, surprisingly, also in nifH genes. Our results shed light on the ecological significance of

different bacterial groups of the lichen microbiome, indicating which taxa are maintained across space, thus suggesting a necessary involvement in the lichen symbiosis. Fierer (2008) suggested that both dispersal and colonization success depend on the original density of the population. We suppose that when Pexidartinib vegetative lichen propagules are dispersed, the high-abundant Alphaproteobacteria are maintained for successful colonization of the new site; on the contrary, the original species of both Burkholderia and nitrogen fixers will be lost, and local, better adapted competitors will be uploaded from the new environment. This work was funded by the Austrian Science Foundation FWF to G.B. and M.G. and by a grant of the Austrian Exchange Service OeAD to J.V. We warmly thank Lucia Muggia (Graz) for contributing to the early stage organization of the manuscript and for a critical screening of part of the data. “
“The Lancefield

group C α-hemolytic Streptococcus dysgalactiae ssp. dysgalactiae (GCSD) causes systemic granulomatous inflammatory disease and high mortality rates in infected fish. Superantigen and streptolysin S genes are the most important virulence tuclazepam factors contributing to an invasive streptococcal infection. PCR amplification revealed that all strains isolated from moribund fish harbored the streptolysin S structural gene (sagA). GCSD fish isolates were PCR negative for emm, speA, speB, speC, speM, smeZ, and ssa. However, the size of the streptococcal pyrogenic exotoxin G (spegg) locus, a superantigen, in positive S. dysgalactiae fish and pig strains was variable. The ORF of the spegg locus of 26 GCSD fish strains and one GCSD pig strain was inserted with IS981SC. Interestingly, the ORF of the spegg locus of two fish strains of GCSD collected in Malaysia was inserted with an IS981SC–IS1161 hybrid IS element.

This is less a ′call to arms′, and more a ′call to apps′; althoug

This is less a ′call to arms′, and more a ′call to apps′; although in reality these are one and the same. Apps are the modern-day weaponry being used to ′conquer′ the hearts and minds of the population, and their potential for health is no less than in other areas. The time is right for the use of the most appropriate ′modern-day weaponry′ against Afatinib datasheet the chronic diseases we are observing in people with HIV. The lessons that we learn by improving screening in this motivated population can be more widely applied to other disease groups, and also to the healthy ageing population. Conflicts of interest: BP has received research grant funding, and sponsorship to attend

conferences or advisory boards from Abbott Laboratories, ViiV Pharmaceuticals and Merck Laboratories. “
“The durability of combination antiretroviral therapy (cART) regimens selleck screening library can be measured as time to discontinuation because of toxicity or treatment failure, development of clinical disease or serious long-term

adverse events. The aim of this analysis was to compare the durability of nevirapine, efavirenz and lopinavir regimens based on these measures. Patients starting a nevirapine, efavirenz or lopinavir-based cART regimen for the first time after 1 January 2000 were included in the analysis. Follow-up started ≥3 months after initiation of treatment if viral load was <500 HIV-1 RNA copies/mL. Durability was measured as discontinuation rate or development/worsening of clinical markers. A total of 603 patients (21%) started nevirapine-based cART, 1465 (51%) efavirenz, and 818 (28%) lopinavir. After adjustment there was no significant difference in the risk of discontinuation for any reason between

the groups Cediranib (AZD2171) on nevirapine and efavirenz (P=0.43) or lopinavir (P=0.13). Compared with the nevirapine group, those on efavirenz had a 48% (P=0.0002) and those on lopinavir a 63% (P<0.0001) lower risk of discontinuation because of treatment failure and a 31% (P=0.01) and 66% (P<.0001) higher risk, respectively, of discontinuation because of toxicities or patient/physician choice. There were no significant differences in the incidence of non-AIDS-related events, worsening anaemia, severe weight loss, increased aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels or increased total cholesterol. Compared with patients on nevirapine, those on lopinavir had an 80% higher incidence of high-density lipoprotein (HDL) cholesterol decreasing below 0.9 mmol/L (P=0.003), but there was no significant difference in this variable between those on nevirapine and those on efavirenz (P=0.39). The long-term durability of nevirapine-based cART, based on risk of all-cause discontinuation and development of long-term adverse events, was comparable to that of efavirenz or lopinavir, in patients in routine clinical practice across Europe who initially tolerated and virologically responded to their regimen.

2b) At 8 μg mL−1 apigenin, the α-hemolysin could not be detected

2b). At 8 μg mL−1 apigenin, the α-hemolysin could not be detected in the culture supernatant. Alpha-hemolysin is encoded by the hla gene, which is regulated by the Agr two-component system. Consequently, a real-time RT-PCR p38 MAPK activity assay was performed to examine whether apigenin can affect the transcription

of the hla and agrA genes. As shown in Fig. 2c and d, the transcription of hla and agrA was remarkably inhibited when increasing concentrations of apigenin were added. When cells were co-cultured with 8 μg mL−1 apigenin, the transcriptional levels of the hla and agrA genes were reduced 14.03- and 9.13-fold, respectively. Human A549 alveolar epithelial cells are widely used in pulmonary disease models (Nizet et al., 1996; Hirst et al., 2002). Previous studies have demonstrated that α-hemolysin can cause A549 cell injury in a dose-dependent manner (Liang et al., 2009). Therefore, apigenin was assayed for its ability to protect A549 cells from α-hemolysin-mediated cell injury. In this study, A549 cells Doxorubicin solubility dmso were co-cultured with S. aureus and different concentrations of apigenin. Cells were strained with a live/dead (green/red) reagent. As shown in Fig. 3a, uninfected cells retained a green fluorophore, while dead cells were red (Fig. 3b). As

shown in Fig. 3c, apigenin conferred significant protection from cell injury at the concentration of 8 μg mL−1. Furthermore, a LDH release assay was performed to quantify cell injury, and as shown in Fig 3e, apigenin provided a dose-dependent protection to co-cultures of A549 cells with concentrations from 1 to 8 μg mL−1. Alpha-hemolysin has been established as the main virulence factor in mouse models of S. aureus pneumonia (McElroy et al., 2002; Gomez et al., 2004). Alpha-hemolysin has also been shown to damage the air–blood dipyridamole barrier in a rat model of S. aureus lung infection (McElroy et al., 1999). On the foundation of in vitro research that apigenin can reduce the expression of α-hemolysin at very low concentrations, a S. aureus-mediated mouse pneumonia model was used to investigate

the in vivo protective effects of apigenin. Mice were infected intranasally with a 30-μL S. aureus 8325-4 suspension as described in the ‘Materials and methods’. Next, mice were subcutaneously administered either PBS or 50 mg kg−1 apigenin. The hla− strain DU1090 was used as a negative control. The bacteria burden was quantified to evaluate the influence of apigenin on the survival in the lungs. As shown in Fig. 4a, the CFUs of lungs from infected mice treated with 50 mg kg−1 were remarkably lower than those treated with PBS. The lung tissues of S. aureus 8325-4-infected mice that had been treated with apigenin were pink and spongy. However, the lung tissues of mice that were treated with PBS were kermesinus and had a firm texture (Fig. 4b).