Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
dual recombinant lactococcus lactis for enhanced delivery of dna vaccine reporter plasmid pperdby.food grade lactococcus lactis (l. lactis) has been widely used as an antigen and dna delivery vehicle. we had previously reported the use of non-invasive l. lactis for the delivery of newly constructed immunostimulatory dna vaccine reporter plasmid, pperdby. in the present report, we outline the construction of dual recombinant l. lactis expressing internalin a of listeria monocytogenes and harbouring pperdby (ll inla+ pperdby) to enhance the dna delivery efficiency of l. lactis. after confirmat ...201728258689
antimicrobial resistance profiles of listeria monocytogenes and listeria innocua isolated from ready-to-eat products of animal origin in spain.the objective of this work was to investigate the antimicrobial resistance in listeria spp. isolated from food of animal origin. a total of 50 listeria strains isolated from meat and dairy products, consisting of 7 listeria monocytogenes and 43 listeria innocua strains, were characterized for antimicrobial susceptibility against nine antimicrobials. the strains were screened by real-time pcr for the presence of antimicrobial resistance genes: tet m, tet l, mef a, msr a, erm a, erm b, lnu a, and ...201728355096
successful treatment of listeria monocytogenes prosthetic valve endocarditis using rifampicin and benzylpenicillin in combination with valve replacement.introduction.listeria monocytogenes is an uncommon cause of prosthetic valve endocarditis (pve). recommended antimicrobial therapy typically includes intravenous β-lactams with or without synergistic aminoglycosides. in vitro studies have previously identified antagonism when rifampicin has been used in combination with β-lactams. however, in vivo data of rifampicin use are limited despite its enhanced anti-biofilm activity. case presentation. a 63-year-old male presented with fever and back pai ...201728348807
stevia rebaudiana bertoni effect on the hemolytic potential of listeria monocytogenes.the effect of stevia rebaudiana bertoni on the hemolytic potential of listeria monocytogenes was studied by means of the assessment of the listeriolysin o (llo) production. the three factors under study, stevia concentration in the range [0-2.5] % (w/v), incubation temperature (10 and 37°c), and exposure time (0-65h) significantly affected (p≤0.05) the hemolytic activity of l. monocytogenes. results showed that at the lower incubation temperature the hemolytic potential of the bacterium was sign ...201728346877
antimicrobial medium- and long-chain free fatty acids prevent prfa-dependent activation of virulence genes in listeria monocytogenes.the foodborne pathogen listeria monocytogenes is the causative agent of the invasive disease listeriosis. infection by l. monocytogenes involves bacterial crossing of the intestinal barrier and intracellular replication in a variety of host cells. the prfa protein is the master regulator of virulence factors required for bacterial entry, intracellular replication and cell-to-cell spread. prfa-dependent activation of virulence genes occurs primarily in the blood and during intracellular infection ...201728344104
membrane fatty acid composition as a determinant of listeria monocytogenes sensitivity to trans-cinnamaldehyde.trans-cinnamaldehyde, the major compound of cinnamon essential oil, is a potentially interesting natural antimicrobial food preservative. although a number of studies have addressed its mode of action, the factors that determine bacterial sensitivity or tolerance to trans-cinnamaldehyde are poorly understood. we report the detailed characterization of a listeria monocytogenes scott a trans-cinnamaldehyde hypersensitive mutant defective in ilve, which catalyzes the reversible transamination of br ...201728342836
gut symbiotic microbes imprint intestinal immune cells with the innate receptor slamf4 which contributes to gut immune protection against enteric pathogens.interactions between host immune cells and gut microbiota are crucial for the integrity and function of the intestine. how these interactions regulate immune cell responses in the intestine remains a major gap in the field.201728341747
genotypes associated with listeria monocytogenes isolates displaying impaired or enhanced tolerances to cold, salt, acid, or desiccation stress.the human pathogen listeria monocytogenes is a large concern in the food industry where its continuous detection in food products has caused a string of recalls in north america and europe. most recognized for its ability to grow in foods during refrigerated storage, l. monocytogenes can also tolerate several other food-related stresses with some strains possessing higher levels of tolerances than others. the objective of this study was to use a combination of phenotypic analyses and whole genom ...201728337186
listeria monocytogenes endophthalmitis after intermediate uveitis and ppv for retinal detachment. 201728329887
sensing of bacterial cyclic dinucleotides by the oxidoreductase recon promotes nf-κb activation and shapes a proinflammatory antibacterial state.bacterial and host cyclic dinucleotides (cdns) mediate cytosolic immune responses through the sting signaling pathway, although evidence suggests that alternative pathways exist. we used cdn-conjugated beads to biochemically isolate host receptors for bacterial cdns, and we identified the oxidoreductase recon. high-affinity cdn binding inhibited recon enzyme activity by simultaneously blocking the substrate and cosubstrate sites, as revealed by structural analyses. during bacterial infection of ...201728329705
listeria monocytogenes cadc regulates cadmium efflux and fine-tunes lipoprotein localization to escape the host immune response and promote infection.listeria monocytogenes (lm) is a major intracellular human foodborne bacterial pathogen. we previously revealed lm-cadc as highly expressed during mouse infection. here we show that lm-cadc is a sequence-specific, dna-binding and cadmium-dependent regulator of cada, an efflux pump conferring cadmium resistance. cadc, but not cada, is required for lm infection in vivo. interestingly, cadc also directly represses lspb, a gene encoding a lipoprotein signal peptidase whose expression appears detrime ...201728329127
suspected giant cell aortitis : from multiple aortic structural damage to fatal listeria sepsi. a case report.giant cell arteritis ( gca) is an inflammatory vasculopathy affecting large and middle-sized vessels , specifically cranial arteries derived from carotid artery. isolated extracranial vessel involvement can occur. interest in extravascular manifestations is recently increasing because of diffusion of sensitive and specific imaging tools such as 18fdg pet tc . patients have an increased relative risk of severe infection. listeria monocytogenes infection risk is increased, and vascular system invo ...201728323232
impairment of the class iia bacteriocin receptor function and membrane structural changes are associated to enterocin crl35 high resistance in listeria monocytogenes.enterocin crl35 is a class iia bacteriocin with anti-listeria activity. resistance to these peptides has been associated with either the downregulation of the receptor expression or changes in the membrane and cell walls. the scope of the present work was to characterize enterocin crl35 resistant listeria strains with mics more than 10,000 times higher than the mic of the wt sensitive strain.201728323072
listeria monocytogenes meningitis preceded by acute cholangitis.listeria monocytogenes is a well-known cause of meningitis in immunocompromised patients. this organism has a growing significance for community-acquired meningitis, which should have ampicillin added to the usual regimen. we describe a case of l. monocytogenes meningitis preceded by cholangitis. this case suggests gastrointestinal symptoms preceding meningitis may be a clue of listeriosis. it is important for physicians to consider l. monocytogenes as a cause of bacterial meningitis in patients ...201728320704
efficacy of a sonicating swab for removal and capture of listeria monocytogenes in biofilm on stainless steel.listeria monocytogenes is of great concern in food processing facilities because it persists in biofilms, potentiating biotransfer. stainless steel is commonly used for food contact surfaces and transport containers. l. monocytogenes biofilm on stainless steel served as a model system for surface sampling to test the performance of a sonicating swab in comparison to a standard cotton swab. swab performance and consistency were determined using total viable counts. stainless steel coupons sampled ...201728314729
bacterial detection using peptide-based platform and impedance spectroscopy.antimicrobial peptides have the ability to function as bio-recognition elements in the detection of bacteria. for instance, we showed that leucocin a, an antimicrobial peptide from class iia bacteriocins, binds gram-positive listeria monocytogenes with higher affinity than other gram-positive bacteria like s. aureus, l. innocua, and e. faecalis. the binding was detected using impedance spectroscopy when leucocin a immobilized on impedance electrodes binds bacteria from a sample. here we highligh ...201728299684
anti-listeria activity of lactic acid bacteria in two traditional sicilian cheeses.listeria monocytogenes is a pathogen frequently found in dairy products, and its growth is difficult to control. bacteriocin-like inhibitory substances (blis), produced by lactic acid bacteria (lab), having proven in vitro anti-listeria activity, could provide an innovative approach to control l. monocytogenes; however, this application needs to be evaluated in vivo. in this study, twenty lab strains isolated from different sicilian dairy environments were tested for control of growth of l. mono ...201728299290
biofilm-producing ability of listeria monocytogenes isolates from brazilian cheese processing plants.the persistence of listeria monocytogenes in food industry environments has been associated to the ability of specific isolates to produce biofilms. this study aimed to evaluate the biofilm production of 85 l. monocytogenes strains previously isolated from samples of cheese, brine and the environment of two cheese processing plants located in são paulo, brazil. the l. monocytogenes isolates belonged to serotypes 4b, 1/2b and 1/2c, yielded 30 different pulsotypes by pulsed-field gel electrophores ...201728290331
metabolic determinants in listeria monocytogenes anaerobic listeriolysin o production.listeria monocytogenes is a human pathogen and a facultative anaerobe. to better understand how anaerobic growth affects l. monocytogenes pathogenesis, we first showed that anaerobic growth led to decreased growth and changes in surface morphology. moreover, compared to aerobically grown bacteria, anaerobically grown l. monocytogenes established higher level of invasion but decreased intracellular growth and actin polymerization in cultured cells. the production of listeriolysin o (llo) was sign ...201728289786
control of recombination directionality by the listeria phage a118 protein gp44 and the coiled-coil motif of its serine integrase.the serine integrase of phage a118 catalyzes integrative recombination between attp on the phage and a specific attb locus on the chromosome of listeriamonocytogenes but is unable to promote excisive recombination between the hybrid attl and attr sites found on the integrated prophage without assistance from a recombination directionality factor (rdf). we have identified and characterized the phage-encoded rdf, gp44, which activates the a118 integrase for excision and inhibits integration. gp44 ...201728289084
listeria monocytogenes ability to survive desiccation: influence of serotype, origin, virulence, and genotype.listeria monocytogenes, a bacterium that is responsible for listeriosis, is a very diverse species. desiccation resistance has been rarely studied in l. monocytogenes, although it is a stress that is largely encountered by this microorganism in food-processing environments and that could be managed to prevent its presence. the objective of this study was to evaluate the resistance of 30 l. monocytogenes strains to moderate desiccation (75% relative humidity) and evaluate the correlation of such ...201728288399
intractable neck pain in an oncologic palliative care setting: is cancer always the answer?refractory pain is a common manifestation in an oncologic palliative care setting and represents a major challenge for health care professionals involved in care provision. the underlying neoplasm and its dissemination are the foremost pathophysiologic mechanism for the development of pain in patients with advanced cancer. nonetheless, other etiologies such as trauma and infections need to be considered by clinicians in this particular care setting. the authors present the case of a patient with ...201728287358
efficient control of chronic lcmv infection by a cd4 t cell epitope-based heterologous prime-boost vaccination in a murine model.cd4(+) t cells are essential for sustaining cd8(+) t cell responses during a chronic infection. the adoptive transfer of virus-specific cd4(+) t cells has been shown to efficiently rescue exhausted cd8(+) t cells. however, the question of whether endogenous virus-specific cd4(+) t cell responses can be enhanced by certain vaccination strategies and subsequently reinvigorate exhausted cd8(+) t cells remains unexplored. in this study, we developed a cd4(+) t cell epitope-based heterologous prime-b ...201728287115
teriyaki sauce with carvacrol or thymol effectively controls escherichia coli o157:h7, listeria monocytogenes, salmonella typhimurium, and indigenous flora in marinated beef and marinade.an effective bactericidal cold-marinating method for beef products is described, exploiting the synergism between soy sauce and natural compounds (carvacrol, cv or thymol, tm) to reduce microbiological risks. beef slices inoculated with escherichia coli o157:h7, listeria monocytogenes, and salmonella typhimurium (3.1-3.5logcfu/g) were marinated in a teriyaki sauce with or without cv and tm (0.3 and 0.5%). after 1, 3, and 7days at 4°c, indigenous microflora population, color, lipid oxidation, mar ...201728285115
listeria monocytogenes in fresh produce: outbreaks, prevalence and contamination levels.listeria monocytogenes, a member of the genus listeria, is widely distributed in agricultural environments, such as soil, manure and water. this organism is a recognized foodborne pathogenic bacterium that causes many diseases, from mild gastroenteritis to severe blood and/or central nervous system infections, as well as abortion in pregnant women. generally, processed ready-to-eat and cold-stored meat and dairy products are considered high-risk foods for l. monocytogenes infections that cause h ...201728282938
the complement anaphylatoxins c5a and c3a suppress ifn-β production in response to listeria monocytogenes by inhibition of the cyclic dinucleotide-activated cytosolic surveillance pathway.listeria monocytogenes is an intracellular gram-positive bacterium that induces expression of type i ifns (ifn-α/ifn-β) during infection. these cytokines are detrimental to the host during infection by priming leukocytes to undergo l. monocytogenes-mediated apoptosis. our previous studies showed that c5ar1(-/-) and c3ar(-/-) mice are highly susceptible to l. monocytogenes infection as a result of increased ifn-β-mediated apoptosis of major leukocyte cell populations, including cd4(+) and cd8(+) ...201728275134
virulence genes and genetic relationship of l. monocytogenes isolated from human and food sources in brazil.the herein presented assay provided a bacteriological and molecular characterization of 100 samples of l. monocytogenes isolated from human (43) and food (57) sources, from several regions of brazil, and collected between 1975 and 2013. antigenic characterization defined 49% of serotype 4b samples, followed by 28% of serotype 1/2b, 14% of serotype 1/2c, 8% of serotype 1/2a, and 1% of serotype 3b. both type of samples from human and food origin express the same serotype distribution. multiplex pc ...201728274807
inactivation of listeria monocytogenes on frozen red raspberries by using uv-c light.in this study, the efficacy of uv-c treatment was determined on the reduction of foodborne pathogens on artificially contaminated frozen food surfaces. at first, the uv-c inactivation rates on 100 μl of the respective cocktails of escherichia coli o157:h7, salmonella , and listeria monocytogenes covered underneath 0.5-cm-thick ice were examined. simultaneously, the energy percentage of uv-c transmitted through the ice was determined. the experiments showed that more than 65% of the uv-c light en ...201728272923
genetic characterization of listeria monocytogenes isolates from industrial and retail ready-to-eat meat-based foods and their relationship with clinical strains from human listeriosis in portugal.listeria monocytogenes isolates (n = 81) recovered from ready-to-eat meat-based food products (rtemp) collected in industrial processing plants and retail establishments were genetically characterized for comparison with those from human clinical cases of listeriosis (n = 49). the aim was to assess rtemp as a possible food source for human infection. l. monocytogenes was detected in 12.5% of the rtemp samples, and in some cases, counts were above the european food safety criteria. all isolates w ...201728272920
in situ generation of chlorine dioxide for surface decontamination of produce.fresh fruits and vegetables are frequently contaminated with bacterial pathogens and implicated in foodborne illnesses. the objective of this study was to develop a unique surface decontamination method for produce using sodium chlorite and an acid in a sequential treatment. the surfaces of cantaloupe rinds, peels of cucumbers, stem scars of grape tomatoes, and leaves of baby spinach were inoculated with salmonella or listeria monocytogenes at 5 to 6 log cfu/g, submerged in 1.6 to 4% sodium chlo ...201728272919
listeria monocytogenes internalizes in romaine lettuce grown in greenhouse conditions.listeria monocytogenes has been implicated in a number of outbreaks involving fresh produce, including an outbreak in 2016 resulting from contaminated packaged salads. the persistence and internalization potential of l. monocytogenes in romaine lettuce was evaluated, and the persistence of two l. monocytogenes strains was assessed on three romaine lettuce cultivars. seeds were germinated, and plants grown in three soil types (i.e., standard potting mix, autoclaved potting mix, and top soil) and ...201728271926
a 3-year multi-food study of the presence and persistence of listeria monocytogenes in 54 small food businesses in ireland.the problem of assessing the occurrence of the food-borne pathogen listeria monocytogenes in the food chain, and therefore the risk of exposure of the human population, is often challenging because of the limited scope of some studies. in this study the occurrence of l. monocytogenes in food from four major food groups, dairy products, meats, seafood and vegetables, and associated food processing environments in ireland was studied over a three-year period. fifty-four small food businesses parti ...201728271853
structural insights into glutathione-mediated activation of the master regulator prfa in listeria monocytogenes. 201728271443
listeria monocytogenes induces an interferon-enhanced activation of the integrated stress response that is detrimental for resolution of infection in mice.type i interferons (ifns) induce a detrimental response during listeria monocytogenes (l. monocytogenes) infection. we were interested in identifying mechanisms linking ifn signaling to negative host responses against l. monocytogenes infection. herein we found that infection of myeloid cells with l. monocytogenes led to a coordinated induction of type i ifns and activation of the integrated stress response (isr). infected cells did not induce xbp1 splicing or bip upregulation, indicating that t ...201728267207
the position of prenylation of isoflavonoids and stilbenoids from legumes (fabaceae) modulates the antimicrobial activity against gram positive pathogens.the legume plant family (fabaceae) is a potential source of antimicrobial phytochemicals. molecular diversity in phytochemicals of legume extracts was enhanced by germination and fungal elicitation of seven legume species, as established by rp-uhplc-uv-ms. the relationship between phytochemical composition, including different types of skeletons and substitutions, and antibacterial properties of extracts was investigated. extracts rich in prenylated isoflavonoids and stilbenoids showed potent an ...201728254012
microbial survey of ready-to-eat salad ingredients sold at retail reveals the occurrence and the persistence of listeria monocytogenes sequence types 2 and 87 in pre-packed smoked salmon.as the preparation of salads involves extensive handling and the use of uncooked ingredients, they are particularly vulnerable to microbial contamination. this study aimed to determine the microbial safety and quality of pre-packed salads and salad bar ingredients sold in singapore, so as to identify public health risks that could arise from consuming salads and to determine areas for improvement in the management of food safety.201728245788
apoptotic cells enhance pathogenesis of listeria monocytogenes.infections by pathogenic microorganisms elicit host immune responses, which crucially limit those infections. pathogens employ various strategies to evade host immunity. we have identified the exploitation of the repertoire of potent immunosuppressive responses elicited normally by apoptotic cells ("innate apoptotic immunity"; iai) as one of these strategies. in the case of listeria monocytogenes, an environmentally ubiquitous, foodborne bacterial pathogen capable of causing life-threatening inv ...201728242425
comparative phenotypic and genotypic analysis of swiss and finnish listeria monocytogenes isolates with respect to benzalkonium chloride resistance.reduced susceptibility of listeria monocytogenes to benzalkonium chloride (bc), a quaternary ammonium compound widely used in food processing and hospital environments, is a growing public health and food safety concern. the minimal inhibitory concentration of bc on 392 l. monocytogenes strains from switzerland (ch) and finland (fin) was determined. within this strain collection, benzalkonium chloride resistance was observed in 12.3% (24/195) of swiss and 10.6% (21/197) of finnish strains. in bo ...201728386248
local outbreak of listeria monocytogenes serotype 4b sequence type 6 due to contaminated meat pâté.in january and february 2016, five cases of confirmed and two cases of probable infection due to listeria monocytogenes serotype 4b, sequence type (st) 6 belonging to a single pulsed-field gel electrophoresis pulsotype pattern were registered in a region of southern switzerland. l. monocytogenes was detected in blood samples (four cases) and pleural fluid (one case). furthermore, l. monocytogenes 4b st6 was detected in a stool sample of an asymptomatic person exposed to a common food. forthwith, ...201728379731
listeriolysin s is a streptolysin s-like virulence factor that targets exclusively prokaryotic cells in vivo.streptolysin s (sls)-like virulence factors from clinically relevant gram-positive pathogens have been proposed to behave as potent cytotoxins, playing key roles in tissue infection. listeriolysin s (lls) is an sls-like hemolysin/bacteriocin present among listeria monocytogenes strains responsible for human listeriosis outbreaks. as lls cytotoxic activity has been associated with virulence, we investigated the lls-specific contribution to host tissue infection. surprisingly, we first show that l ...201728377528
listeria monocytogenes infection associated with alemtuzumab - - a case for better preventive strategies.the mortality of septicaemia, meningitis and encephalitis caused by listeria monocytogenes is 20-40%. twenty-one cases of invasive listeriosis associated with alemtuzumab, including at least 16 in patients with multiple sclerosis, have been published or reported to the world health organization case safety reports database. three cases were fatal, including at least one patient treated for multiple sclerosis in 2016.201728376817
whey protein isolate/cellulose nanofibre/tio2 nanoparticle/rosemary essential oil nanocomposite film: its effect on microbial and sensory quality of lamb meat and growth of common foodborne pathogenic bacteria during refrigeration.the use of biodegradable nanocomposite films in active packaging is of great importance since they can have a controlled release of antimicrobial compounds. this study was conducted to evaluate the efficacy of whey protein isolate (wpi)/cellulose nanofibre (cnf) nanocomposite films containing 1.0% (w/w) titanium dioxide (tio2) and 2.0% (w/v) rosemary essential oil (reo) in preserving the microbial and sensory quality of lamb meat during the storage at 4±1°c. initially, the best concentration of ...201728376399
contamination by salmonella spp., campylobacter spp. and listeria spp. of most popular chicken- and pork-sausages sold in reunion island.one of the most popular meat products of the local "cuisine" is sausage composed with 100% chicken or 100% pork. in this study, we aimed to determine the presence of salmonella spp., campylobacter spp. and listeria spp. in chicken- and pork-sausages, quantify salmonella spp. population and identify the factors that could be associated with contamination in the outlets. two hundred and three batches of pork and chicken sausages were randomly collected from 67 local outlets (supermarkets, grocerie ...201728371717
the prevalence of listeria monocytogenes and staphylococcus aureus and their virulence genes in bulk tank milk in kosovo.milk is considered to be a healthy, nutritious food product. microbiological quality is an important aspect in evaluating the quality of milk.201728368859
listeria monocytogenes cadc regulates cadmium efflux and fine-tunes lipoprotein localization to escape the host immune response and promote infection.listeria monocytogenes (lm) is a major intracellular human foodborne bacterial pathogen. we previously revealed lm-cadc as highly expressed during mouse infection. here we show that lm-cadc is a sequence-specific, dna-binding and cadmium-dependent regulator of cada, an efflux pump conferring cadmium resistance. cadc, but not cada, is required for lm infection in vivo. interestingly, cadc also directly represses lspb, a gene encoding a lipoprotein signal peptidase whose expression appears detrime ...201728368435
listeria monocytogenes: a rare cause of endophthalmitis, a case report.listeria monocytogenes is a known cause of gastroenteritis. invasive disease can follow bacteremia causing meningoencephalitis, endocarditis and spontaneous miscarriages in immunocompromised patients and pregnant women respectively. we present the first case in england of endogenous endophthalmitis caused by l. monocytogenes following acute gastroenteritis in an immunocompetent host. a 50-year-old south asian female presented with acute painful unilateral visual loss occurring shortly after an e ...201728367407
comparative effects of untreated and 3-methacryloxypropyltrimethoxysilane treated zno nanoparticle reinforcement on properties of polylactide-based nanocomposite films.polylactide (pla) nanocomposites characterized by antimicrobial properties are gaining increasing attention for food packaging. in this contribution, the pla based nanocomposite films with multifunctional end-use properties were achieved by incorporating zno nanoparticles (nps) [untreated: zno(ut) and 3-methacryloxypropyltrimethoxysilane treated: zno(st)] into polymer matrix via solvent casting method. the zno(st) prevented the degradation of pla at higher temperature and improved the mechanical ...201728366847
a type i ifn-dependent dna damage response regulates the genetic program and inflammasome activation in macrophages.macrophages produce genotoxic agents, such as reactive oxygen and nitrogen species, that kill invading pathogens. here we show that these agents activate the dna damage response (ddr) kinases atm and dna-pkcs through the generation of double stranded breaks (dsbs) in murine macrophage genomic dna. in contrast to other cell types, initiation of this ddr depends on signaling from the type i interferon receptor. once activated, atm and dna-pkcs regulate a genetic program with diverse immune functio ...201728362262
peritonitis as the first presentation of disseminated listeriosis in a patient on peritoneal dialysis-a case report.infections with listeria monocytogenes are uncommon but serious, with mortality rate approaching 30% in cases of systemic involvement despite first-line therapy. they are usually caused by ingestion of contaminated foods, but spontaneous infections have also been described. listeria monocytogenes is a rare cause of peritonitis, and most of the published cases are in patients with cirrhosis and ascites. there are a few reported cases of listeria peritonitis associated with peritoneal dialysis (pd ...201728360372
corrigendum: uncovering listeria monocytogenes hypervirulence by harnessing its biodiversity. 201728358126
stochastic and differential activation of σ(b) and prfa in listeria monocytogenes at the single cell level under different environmental stress conditions.during host infection, the foodborne pathogen listeria monocytogenes must sense and respond to rapidly changing environmental conditions. two transcriptional regulators, the alternative sigma factor b (σ(b)) and the positive regulatory factor a (prfa), are key contributors to the transcriptomic responses that enable bacterial survival in the host gastrointestinal tract and invasion of host duodenal cells. increases in temperature and osmolarity induce activity of these proteins; such conditions ...201728352251
acute fetal demise with first trimester maternal infection resulting from listeria monocytogenes in a nonhuman primate model.infection with listeria monocytogenes during pregnancy is associated with miscarriage, preterm birth, and neonatal complications, including sepsis and meningitis. while the risk of these conditions is thought to be greatest during the third trimester of pregnancy, the determinants of fetoplacental susceptibility to infection, the contribution of gestational age, and the in vivo progression of disease at the maternal-fetal interface are poorly understood. we developed a nonhuman primate model of ...201728223455
listeria monocytogenes in smoked salmon and other smoked fish at retail in italy: frequency of contamination and strain characterization in products from different manufacturers.seven hundred seventy-eight samples of packaged smoked fish (774 smoked salmon and 4 smoked swordfish) on sale in italy, from 50 different manufacturers located in 12 european union countries, were purchased from the italian market between may and december 2011. the surface temperatures of the samples on sale ranged from 0 to 13°c (3.4 ± 1.5°c, mean ± sd). six hundred eighty (87.4%) of 778 samples were stored at ≤4°c. one hundred fifty-seven samples (20.2%, 95% confidence interval 17.5 to 23.1%) ...201728221976
fate of listeria monocytogenes , pathogenic yersinia enterocolitica , and escherichia coli o157:h7 gfp(+) in ready-to-eat salad during cold storage: what is the risk to consumers?in this study, we investigated the fate of listeria monocytogenes , pathogenic yersinia enterocolitica , and escherichia coli o157:h7 gfp(+) inoculated in low numbers into ready-to-eat baby spinach and mixed-ingredient salad (baby spinach with chicken meat). samples were stored at recommended maximum refrigerator temperature (8°c in sweden) or at an abuse temperature (15°c) for up to 7 days. mixed-ingredient salad supported considerable growth when stored at 15°c during shelf life (3 days), with ...201728221975
listeria monocytogenes 10403s arginine repressor argr finely tunes arginine metabolism regulation under acidic conditions.listeria monocytogenes is able to colonize human and animal intestinal tracts and to subsequently cross the intestinal barrier, causing systemic infection. for successful establishment of infection, l. monocytogenes must survive the low ph environment of the stomach. l. monocytogenes encodes a functional argr, a transcriptional regulator belonging to the argr/ahrc arginine repressor family. we aimed at clarifying the specific functions of argr in arginine metabolism regulation, and more importan ...201728217122
monocytes are the predominant cell type associated with listeria monocytogenes in the gut, but they do not serve as an intracellular growth niche.after foodborne transmission of the facultative intracellular bacterial pathogen listeria monocytogenes, most of the bacterial burden in the gut is extracellular. however, we previously demonstrated that intracellular replication in an as yet unidentified cell type was essential for dissemination and systemic spread of l. monocytogenes in this article, we show that the vast majority of cell-associated l. monocytogenes in the gut were adhered to ly6c(hi) monocytes, a cell type that inefficiently ...201728213502
high hydrostatic pressure effects on listeria monocytogenes and l. innocua: evidence for variability in inactivation behaviour and in resistance to pediocin bacha-6111-2.the effect of high hydrostatic pressure (hhp) on the survival of 14 strains of listeria monocytogenes from food or clinical origins, selected to represent different pheno and genotypes, was evaluated. stationary phase cells were submitted to 300, 400 and 500 mpa at 10 °c, for 5 min. a high variability in the resistance of l. monocytogenes to pressure was observed, and particularly two strains isolated from food were significantly more baroresistant than the rest. strains of l. monocytogenes resi ...201728213030
inactivation of escherichia coli o157:h7, salmonella typhimurium, and listeria monocytogenes in ready-to-bake cookie dough by gamma and electron beam irradiation.this study was conducted to investigate the efficacy of gamma and electron beam irradiation to inactivate foodborne pathogens in ready-to-bake cookie dough and to determine the effect on quality by measuring color and texture changes. cookie dough inoculated with escherichia coli o157:h7, salmonella typhimurium, or listeria monocytogenes was subjected to gamma and electron beam irradiation, with doses ranging from 0 to 3 kgy. as the radiation dose increased, the inactivation effect increased amo ...201728213023
prevalence, genetic diversity and antimicrobial resistance of listeria monocytogenes isolated from fresh and smoked fish in poland.a total of 57 out of 301 (18.9%) fresh and smoked fish samples in poland were positive for listeria monocytotgenes. the bacteria were most frequently identified in fresh and smoked salmon (32.0% and 33.8% respectively) as well as in fresh cod (31.8%). only three samples of smoked salmon were contaminated with the bacteria above 100 cfu/g. four molecular serogroups were identified and the most prevalent, 1/2a-3a (40 isolates; 70.2%), was present in samples from both marine (33 strains; 71.7%) and ...201728213022
pathogen biofilm formation on cantaloupe surface and its impact on the antibacterial effect of lauroyl arginate ethyl.pathogen biofilm at fruit surface may pose a particular risk to food safety. in this study, the biofilms of listeria monocytogenes v7 and salmonella enterica serovar typhimurium atcc 13311 on cantaloupe fruit surface were visualized, and the resistance of biofilms against lauroyl arginate ethyl (lae, an antibacterial compound) was evaluated. each bacterium was inoculated on isolated cantaloupe rind surfaces at 10(5)-10(6) cfu/cm(2) and after incubation for 2, 12, 24, and 48 h, the surfaces were ...201728213018
assessment of the antimicrobial activity of olive leaf extract against foodborne bacterial pathogens.olive leaf extract (ole) has been used traditionally as a herbal supplement since it contains polyphenolic compounds with beneficial properties ranging from increasing energy levels, lowering blood pressure, and supporting the cardiovascular and immune systems. in addition to the beneficial effects on human health, ole also has antimicrobial properties. the aim of this work was to investigate the antimicrobial effect of ole against major foodborne pathogens, including listeria monocytogenes, esc ...201728210244
yope specific cd8+ t cells provide protection against systemic and mucosal yersinia pseudotuberculosis infection.prior studies indicated that cd8+ t cells responding to a surrogate single antigen expressed by y. pseudotuberculosis, ovalbumin, were insufficient to protect against yersiniosis. herein we tested the hypothesis that cd8+ t cells reactive to the natural yersinia antigen yope would be more effective at providing mucosal protection. we first confirmed that immunization with the attenuated ksga- strain of y. pseudotuberculosis generated yope-specific cd8+ t cells. these t cells were protective agai ...201728207901
growth of listeria monocytogenes in thawed frozen foods.the growth characteristics of listeria monocytogenes inoculated onto frozen foods (corn, green peas, crabmeat, and shrimp) and thawed by being stored at 4, 8, 12, and 20°c were investigated. the growth parameters, lag-phase duration (lpd) and exponential growth rate (egr), were determined by using a two-phase linear growth model as a primary model and a square root model for egr and a quadratic model for lpd as secondary models, based on the growth data. the egr model predictions were compared w ...201728207303
nanoengineered eggshell-silver tailored copolyester polymer blend film with antimicrobial properties.in this study, the reinforcement effect of different proportions of eggshell/silver (es-ag) nanomaterial on the structural and antimicrobial properties of 70/30 poly(butylene-co-adipate terephthalate)/polylactic acid (pbat/pla) immiscible blends was investigated. the es-ag was synthesized using a single step ball milling process and characterized with x-ray diffraction (xrd), x-ray photoelectron spectroscopy (xps), and transmission electron microscopy (tem). these results confirmed the existence ...201728206760
tim-3 inhibits macrophage control of listeria monocytogenes by inhibiting nrf2.t cell immunoglobulin mucin-3 (tim-3) is an immune checkpoint inhibitor and its dysregulation has been related to t cell tolerance and many immune disorders, such as tumors and infection tolerance. however, the physiopathology roles of tim-3 in innate immunity remain elusive. here, we demonstrate that tim-3 inhibits macrophage phagocytosis of l. monocytogenes by inhibiting the nuclear erythroid 2-related factor 2 (nrf2) signaling pathway and increases bacterial burden. tim-3 signaling promotes n ...201728205579
requirement of the rna-binding protein smpb during intracellular growth of listeria monocytogenes.bacterial trans-translation is the main quality control mechanism employed to relieve stalled ribosomes. trans-translation is mediated by the small protein b (smpb) and transfer-mrna (tmrna) ribonucleoprotein complex, which interacts with translational complexes stalled at the 3' end of non-stop mrnas to release the stalled ribosomes thereby targeting the nascent polypeptides and truncated mrnas for degradation. the trans-translation system exists with a few exceptions in all bacteria. in the pr ...201728202229
morphological change and decreasing transfer rate of biofilm-featured listeria monocytogenes egde.listeria monocytogenes , a lethal foodborne pathogen, has the ability to resist the hostile food processing environment and thus frequently contaminates ready-to-eat foods during processing. it is commonly accepted that the tendency of l. monocytogenes ' to generate biofilms on various surfaces enhances its resistance to the harshness of the food processing environment. however, the role of biofilm formation in the transferability of l. monocytogenes egde remains controversial. we examined the g ...201728199146
n-terminomics identifies prli42 as a membrane miniprotein conserved in firmicutes and critical for stressosome activation in listeria monocytogenes.to adapt to changing environments, bacteria have evolved numerous pathways that activate stress response genes. in gram-positive bacteria, the stressosome, a cytoplasmic complex, relays external cues and activates the sigma b regulon. the stressosome is structurally well-characterized in bacillus, but how it senses stress remains elusive. here, we report a genome-wide n-terminomic approach in listeria that strikingly led to the discovery of 19 internal translation initiation sites and 6 miniprot ...201728191904
assessing the capacity of growth, survival, and acid adaptive response of listeria monocytogenes during storage of various cheeses and subsequent simulated gastric digestion.different physicochemical and microbiological characteristics of cheeses may affect listeria monocytogenes potential to grow, survive, or exhibit an acid adaptive response during storage and digestion. the objectives of the present study were to assess: i) the survival or growth potential of l.monocytogenes on various cheeses during storage, ii) the effect of initial indigenous microbiota on pathogen growth in comparison to expected growth curves retrieved by existing predictive models, and iii) ...201728189900
invited review: hispanic-style cheeses and their association with listeria monocytogenes.the rise in consumption of hispanic-style cheeses (hsc), due in large part to the increasing hispanic population in the united states, has not been met with advances in food safety sufficient to prevent the numerous outbreaks and recalls due to listeria monocytogenes. hispanic-style cheeses are typically high moisture and have low salt content and low acidity from being subjected to little to no ripening. these conditions necessitate refrigeration to maintain safety and quality, as the majority ...201728189316
32-phosphorus selectively delivered by listeria to pancreatic cancer demonstrates a strong therapeutic effect.our laboratory has developed a novel delivery platform using an attenuated non-toxic and non-pathogenic bacterium listeria monocytogenes that infects tumor cells and selectively survives and multiplies in metastases and primary tumors with help of myeloid-derived suppressor cells (mdsc) and immune suppression in the tumor microenvironment (tme). 32p was efficiently incorporated into the listeria bacteria by starvation of the bacteria in saline, and then cultured in phosphorus-free medium complem ...201728186976
100k pathogen genome project: 306 listeria draft genome sequences for food safety and public health.listeria monocytogenes is a food-associated bacterium that is responsible for food-related illnesses worldwide. this is the initial public release of 306 l. monocytogenes genome sequences as part of the 100k pathogen genome project. these isolates represent global genomic diversity in l. monocytogenes.201728183778
comparative analysis of the bacterial membrane disruption effect of two natural plant antimicrobial peptides.in the medicago truncatula genome about 700 genes code for nodule-specific cysteine-rich (ncr) small peptides that are expressed in the symbiotic organ, the root nodule, where they control terminal differentiation of the endosymbiotic rhizobium bacteria to nitrogen-fixing bacteroids. cationic ncr peptides were predicted to have antimicrobial activities. here antibacterial activities of ncr247, ncr335, polymyxin b (pmb), and streptomycin were investigated and compared on two foodborne pathogens s ...201728167938
rhombencephalitis caused by listeria monocytogenes in a pastured bull.a pastured 2-y-old cross-breed bull developed brainstem encephalitis (rhombencephalitis); listeria monocytogenes was isolated from the brain. in the brainstem, there was perivascular cuffing, multiple microabscesses, and positive immunostaining for l. monocytogenes. samples of bovine feces, water, feedstuffs, milking parlor soil, and bulk tank milk were collected from the dairy farm. seven isolates of the genus listeria were obtained, 6 of l. innocua and 1 of l. monocytogenes, which was found in ...201728166691
assessing the genome level diversity of listeria monocytogenes from contaminated ice cream and environmental samples linked to a listeriosis outbreak in the united states.a listeriosis outbreak in the united states implicated contaminated ice cream produced by one company, which operated 3 facilities. we performed single nucleotide polymorphism (snp)-based whole genome sequencing (wgs) analysis on listeria monocytogenes from food, environmental and clinical sources, identifying two clusters and a single branch, belonging to pcr serogroup iib and genetic lineage i. wgs cluster i, representing one outbreak strain, contained 82 food and environmental isolates from f ...201728166293
activation and exhaustion of antigen-specific cd8(+) t cells occur in different splenic compartments during infection with plasmodium berghei.the spleen is the major organ in which t cells are primed during infection with malaria parasites. however, little is known regarding the dynamics of the immune responses and their localization within the splenic tissue during malaria infection. we examined murine cd8(+) t cell responses during infection with plasmodium berghei using recombinant parasites expressing a model antigen ovalbumin (ova) protein and compared the responses with those elicited by listeria monocytogenes expressing the sam ...201728163249
hot topic: antilisterial activity by endolysin plyp100 in fresh cheese.our objective was to assess the antimicrobial efficacy of a listeria bacteriophage endolysin that may address limitations of current antilisterial processes for fresh cheeses. listeria monocytogenes is highly problematic in the manufacture and processing of ready-to-eat foods due to its environmental persistence and its ability to grow under refrigerated storage. special care must be taken to prevent listerial contamination during the production of fresh cheeses, as their delicate flavor and tex ...201728161174
survival of listeria monocytogenes with different antibiotic resistance patterns to food-associated stresses.the ongoing rise of antibiotic resistant microbial pathogens has become one of the major public health threats worldwide. despite all the effort and actions taken so far, a proliferation of antibiotic resistant (ar) and multi-antibiotic resistant (mar) strains is still observed, including in foodborne pathogens. this trend has been also noted recently for isolates of listeria monocytogenes, a species that, although remaining largely sensitive to clinically relevant antimicrobials, has been repor ...201728157581
listeriolysin s: a bacteriocin from epidemic listeria monocytogenes strains that targets the microbiota.listeria monocytogenes is a gram-positive food-borne pathogen that in humans may traverse the intestinal, placental and blood/brain barriers, causing gastroenteritis, abortions and meningitis. crossing of these barriers is dependent on the bacterial ability to enter host cells, and several l. monocytogenes surface and secreted virulence factors are known to facilitate entry and the intracellular lifecycle. the study of l. monocytogenes strains associated to human listeriosis epidemics has reveal ...201728156183
phloretin attenuates listeria monocytogenes virulence both in vitro and in vivo by simultaneously targeting listeriolysin o and sortase a.the critical roles of sortase a (srta) and listeriolysin o (llo) in listeria monocytogenes pathogenicity render these two virulence factors as ideal targets for the development of anti-virulence agents against l. monocytogenes infection. additionally, the structures of srta and llo are highly conserved among the members of sortase enzyme family and cholesterol dependent toxin family. here, phloretin, a natural polyphenolic compound derived from apples and pears that has little anti-l. monocytoge ...201728154809
diversity and persistence of listeria monocytogenes within the gorgonzola pdo production chain and comparison with clinical isolates from the same area.listeria monocytogenes causes invasive syndromes with high fatality rates in specific population groups. cheeses have been commonly implicated in outbreaks worldwide. gorgonzola is a cheese only produced in northwestern italy (it is the third italian cheese in terms of production and export) and l. monocytogenes is frequently isolated from the production chain. the aims of this study were to assess the distribution of l. monocytogenes virulence types (vts) in isolates collected in gorgonzola pro ...201728153561
diagnosis and treatment of listeria monocytogenes endophthalmitis: a systematic review.describe patient characteristics, treatment, and vision outcomes of listeria monocytogenes endophthalmitis, an exceedingly rare form of listeriosis.201728145786
activity of the pore-forming virulence factor listeriolysin o is reversibly inhibited by naturally occurring s-glutathionylation.cholesterol-dependent cytolysins (cdcs) represent a family of homologous pore-forming proteins secreted by many gram-positive bacterial pathogens. cdcs mediate membrane binding partly through a conserved c-terminal undecapeptide, which contains a single cysteine residue. while mutational changes to other residues in the undecapeptide typically have severe effects, mutation of the cysteine residue to alanine has minor effects on overall protein function. thus, the role of this highly conserved re ...201728138025
case report: when two and ½ men go camping….in patients, rapid identification of bacterial species may help to guide treatment at early stages. new protocols for the identification directly from positive blood culture flasks significantly helped in the presented case report.201728137306
axonal invasion of listeria monocytogenes: implications for early diagnosis with magnetic resonance imaging. 201728131231
mathematical modelling of growth of listeria  monocytogenes in raw chilled pork.the aim of this study was to analyse the growth kinetics of listeria monocytogenes in naturally contaminated chilled pork. a cocktail of 26 meat-borne l. monocytogenes was inoculated to raw or sterile chilled pork to observe its growth at 4, 10, 16, 22 and 28°c respectively. the growth data were fitted by the baranyi model and ratkowsky square-root model. results showed that the baranyi model and ratkowsky square-root model could describe the growth characteristics of l. monocytogenes at differe ...201728129445
stevia-based sweeteners as a promising alternative to table sugar: the effect on listeria monocytogenes and salmonella typhimurium growth dynamics.sugar is commonly substituted with stevia-based products in food industry and in our daily-life. this substitution results in a change in food product characteristic formula and properties that may affect the growth dynamics of food pathogenic and spoilage bacteria. this work studies the effect of table sugar (ts), laboratory sucrose (ls), commercial stevia (st) and steviol glycosides (sg) on the growth dynamics of salmonella typhimurium and listeria monocytogenes. experiments were carried out i ...201728126702
evaluation of ta10 broth for recovery of listeria monocytogenes from ground beef.in 2009, the enrichment broth ta10 was released for simultaneous recovery of salmonella spp., listeria monocytogenes, and escherichia coli o157:h7. this medium was compared with other salmonella enrichment broths [lactose (lac) broth, buffered peptone water (bpw), and universal pre-enrichment (up) broth] for the recovery of heat- and freeze-injured salmonella spp. in beef by the conventional culture method. there was a significant difference between ta10 and lac enrichment broths for detecting i ...201728118577
l-glutamine induces expression of listeria monocytogenes virulence genes.the high environmental adaptability of bacteria is contingent upon their ability to sense changes in their surroundings. bacterial pathogen entry into host poses an abrupt and dramatic environmental change, during which successful pathogens gauge multiple parameters that signal host localization. the facultative human pathogen listeria monocytogenes flourishes in soil, water and food, and in ~50 different animals, and serves as a model for intracellular infection. l. monocytogenes identifies hos ...201728114430
an unusual presentation of listeria monocytogenes rhombencephalitis.we describe a case of 52-year-old woman with a medical history of crohn's disease presented abrupt fever, asymmetrical multiple cranial nerve palsies and focal neurological symptoms localized to the brainstem. the patient was initially diagnosed with ischaemic stroke, because of acute clinical course and results of neuroimaging. cerebrospinal fluid analysis revealed mild infection with negative gram staining and culture. final diagnosis of listeria monocytogenes brainstem infection (rhombencepha ...201728110853
listeria monocytogenes isolation from urine: a series of 15 cases and review. 201728110052
naturally occurring inlb variants that support intragastric listeria monocytogenes infection in mice.listeria monocytogenes is a causative agent of foodborne infection in humans and animals. the virulence factor inlb interacts with mammalian receptor c-met via its internalin domain to provide l. monocytogenes invasion in non-professional phagocytes. naturally occurring inlb internalin domain variants form four subclusters on the maximal likelihood tree. four variants belonging to distinct subclusters were cloned into the vector carrying 3΄ and 5΄-flanking sequences to restore full length inlb a ...201728104777
glutathione and glutathione transferase omega 1 as key posttranslational regulators in macrophages.macrophage activation during phagocytosis or by pattern recognition receptors, such as toll-like receptor 4, leads to the accumulation of reactive oxygen species (ros). ros act as a microbicidal defense mechanism, promoting clearance of infection, allowing for resolution of inflammation. overproduction of ros, however, overwhelms our cellular antioxidant defense system, promoting oxidation of protein machinery, leading to macrophage dysregulation and pathophysiology of chronic inflammatory condi ...201728102119
effect of humidity and temperature on the survival of listeria monocytogenes on surfaces.listeria monocytogenes is a pathogenic bacterium, with human disease and infection linked to dairy products, seafood, ready-to-eat meat and raw & undercooked meats. stainless steel is the most common food preparation surface and therefore, it is important to understand how food storage conditions such as surface materials, temperature and relative humidity can affect survival of l. monocytogenes. in this study, survival of l. monocytogenes on stainless steel was investigated at three temperature ...201728101930
the influence of the toxin/antitoxin mazef on growth and survival of listeria monocytogenes under stress.a major factor in the resilience of listeria monocytogenes is the alternative sigma factor b (σ(b)). type ii toxin/antitoxin (ta) systems are also known to have a role in the bacterial stress response upon activation via the clpp or lon proteases. directly upstream of the σ(b) operon in l. monocytogenes is the ta system mazef, which can cleave mrna at uacmu sites. in this study, we showed that the mazef ta locus does not affect the level of persister formation during treatment with antibiotics i ...201728098783
distinct neurotoxicity profile of listeriolysin o from listeria monocytogenes.cholesterol-dependent cytolysins (cdcs) are protein toxins that originate from gram-positive bacteria and contribute substantially to their pathogenicity. cdcs bind membrane cholesterol and build prepores and lytic pores. some effects of the toxins are observed in non-lytic concentrations. two pathogens, streptococcus pneumoniae and listeria monocytogenes, cause fatal bacterial meningitis, and both produce toxins of the cdc family-pneumolysin and listeriolysin o, respectively. it has been demons ...201728098781
c-di-amp modulates listeria monocytogenes central metabolism to regulate growth, antibiotic resistance and osmoregulation.cyclic diadenosine monophosphate (c-di-amp) is a conserved nucleotide second messenger critical for bacterial growth and resistance to cell wall-active antibiotics. in listeria monocytogenes, the sole diadenylate cyclase, daca, is essential in rich, but not synthetic media and δdaca mutants are highly sensitive to the β-lactam antibiotic cefuroxime. in this study, loss of function mutations in the oligopeptide importer (oppabcdf) and glycine betaine importer (gbuabc) allowed δdaca mutants to gro ...201728097715
functional constituents of wild and cultivated goji (l. barbarum l.) leaves: phytochemical characterization, biological profile, and computational studies.goji (lycium barbarum l.) leaves are emphasized as a functional tea or as dietary supplements. the phenolic compound profile, antioxidant, enzyme inhibitory, antimicrobial, and antimutagenic activities of leaf extracts from two selected cultivars in comparison with wild-growing plants have been evaluated. hplc-dad/esi-tof-ms analysis revealed the presence of phenolic acids and flavonoids with chlorogenic acid and rutin being the dominant compounds in the cultivated plants, whereas rutin and kaem ...201728095717
acquired central hypoventilation following listeria monocytogenes rhombencephalitis. 201728087753
bcap inhibits proliferation and differentiation of myeloid progenitors in the steady state and during demand situations.b-cell adaptor for phosphatidylinositol 3-kinase (bcap) is a signaling adaptor expressed in mature hematopoietic cells, including monocytes and neutrophils. here we investigated the role of bcap in the homeostasis and development of these myeloid lineages. bcap(-/-) mice had more bone marrow (bm) monocytes than wild-type (wt) mice, and in mixed wt:bcap(-/-) bm chimeras, monocytes and neutrophils skewed toward bcap(-/-) origin, showing a competitive advantage for bcap(-/-) myeloid cells. bcap was ...201728087538
Refresh
firstprev
12345678910...
nextlast
Displaying items 101 - 200 of 16792