Publications

susceptibility of legionella strains to the chlorinated biocide, monochloramine.	members of the legionella genus find suitable conditions for their growth and survival in nuclear power plant cooling circuits. to limit the proliferation of legionella pathogenic bacteria in nuclear power plant cooling circuits, and ensure that levels remain below regulatory thresholds, monochloramine treatment can be used. although the treatment is highly effective, i.e. it reduces legionella numbers by over 99%, legionella bacteria can still be detected at low concentrations and rapid re-colo ...	2013	24005820
ubiquitin activates patatin-like phospholipases from multiple bacterial species.	phospholipase a2 enzymes are ubiquitously distributed throughout the prokaryotic and eukaryotic kingdoms and are utilized in a wide array of cellular processes and physiological and immunological responses. several patatin-like phospholipase homologs of exou from pseudomonas aeruginosa were selected on the premise that ubiquitin activation of this class of bacterial enzymes was a conserved process. we found that ubiquitin activated all phospholipases tested in both in vitro and in vivo assays vi ...	2014	25404699
ubiquitin activates patatin-like phospholipases from multiple bacterial species.	phospholipase a2 enzymes are ubiquitously distributed throughout the prokaryotic and eukaryotic kingdoms and are utilized in a wide array of cellular processes and physiological and immunological responses. several patatin-like phospholipase homologs of exou from pseudomonas aeruginosa were selected on the premise that ubiquitin activation of this class of bacterial enzymes was a conserved process. we found that ubiquitin activated all phospholipases tested in both in vitro and in vivo assays vi ...	2014	25404699
identification and biochemical characterization of an acid sphingomyelinase-like protein from the bacterial plant pathogen ralstonia solanacearum that hydrolyzes atp to amp but not sphingomyelin to ceramide.	acid sphingomyelinase (asmase) is a human enzyme that catalyzes the hydrolysis of sphingomyelin to generate the bioactive lipid ceramide and phosphocholine. asmase deficiency is the underlying cause of the genetic diseases niemann-pick type a and b and has been implicated in the onset and progression of a number of other human diseases including cancer, depression, liver, and cardiovascular disease. asmase is the founding member of the asmase protein superfamily, which is a subset of the metallo ...	2014	25144372
importance of branched-chain amino acid utilization in francisella intracellular adaptation.	intracellular bacterial pathogens have adapted their metabolism to optimally utilize the nutrients available in infected host cells. we recently reported the identification of an asparagine transporter required specifically for cytosolic multiplication of francisella. in the present work, we characterized a new member of the major super family (msf) of transporters, involved in isoleucine uptake. we show that this transporter (here designated ilep) plays a critical role in intracellular metaboli ...	2014	25332124
importance of branched-chain amino acid utilization in francisella intracellular adaptation.	intracellular bacterial pathogens have adapted their metabolism to optimally utilize the nutrients available in infected host cells. we recently reported the identification of an asparagine transporter required specifically for cytosolic multiplication of francisella. in the present work, we characterized a new member of the major super family (msf) of transporters, involved in isoleucine uptake. we show that this transporter (here designated ilep) plays a critical role in intracellular metaboli ...	2014	25332124
genome sequence and phenotypic analysis of a first german francisella sp. isolate (w12-1067) not belonging to the species francisella tularensis.	francisella isolates from patients suffering from tularemia in germany are generally strains of the species f. tularensis subsp. holarctica. to our knowledge, no other francisella species are known for germany. recently, a new francisella species could be isolated from a water reservoir of a cooling tower in germany.	2014	24961323
reduction of legionella spp. in water and in soil by a citrus plant extract vapor.	legionnaires' disease is a severe form of pneumonia caused by legionella spp., organisms often isolated from environmental sources, including soil and water. legionella spp. are capable of replicating intracellularly within free-living protozoa, and once this has occurred, legionella is particularly resistant to disinfectants. citrus essential oil (eo) vapors are effective antimicrobials against a range of microorganisms, with reductions of 5 log cells ml(-1) on a variety of surfaces. the aim of ...	2014	25063652
microbial peptidyl-prolyl cis/trans isomerases (ppiases): virulence factors and potential alternative drug targets.	initially discovered in the context of immunomodulation, peptidyl-prolyl cis/trans isomerases (ppiases) were soon identified as enzymes catalyzing the rate-limiting protein folding step at peptidyl bonds preceding proline residues. intense searches revealed that ppiases are a superfamily of proteins consisting of three structurally distinguishable families with representatives in every described species of prokaryote and eukaryote and, recently, even in some giant viruses. despite the clear-cut ...	2014	25184565
ankyrin domains across the tree of life.	ankyrin (ank) repeats are one of the most common amino acid sequence motifs that mediate interactions between proteins of myriad sizes, shapes and functions. we assess their widespread abundance in bacteria and archaea for the first time and demonstrate in bacteria that lifestyle, rather than phylogenetic history, is a predictor of ank repeat abundance. unrelated organisms that forge facultative and obligate symbioses with eukaryotes show enrichment for ank repeats in comparison to free-living b ...	2014	24688847
composition of the dna-uptake complex of vibrio cholerae.	natural competence for transformation is a developmental program that allows certain bacteria to take up free extracellular dna from the environment and integrate this dna into their genome. thereby, natural transformation acts as mode of horizontal gene transfer and impacts bacterial evolution. the number of genes induced upon competence induction varies significantly between organisms. however, all of the naturally competent bacteria possess competence genes that encode so-called dna-uptake ma ...	2014	24558639
a type iv translocated legionella cysteine phytase counteracts intracellular growth restriction by phytate.	the causative agent of legionnaires' pneumonia, legionella pneumophila, colonizes diverse environmental niches, including biofilms, plant material, and protozoa. in these habitats, myo-inositol hexakisphosphate (phytate) is prevalent and used as a phosphate storage compound or as a siderophore. l. pneumophila replicates in protozoa and mammalian phagocytes within a unique "legionella-containing vacuole." the bacteria govern host cell interactions through the icm/dot type iv secretion system (t4s ...	2014	25339170
bacteria, the endoplasmic reticulum and the unfolded protein response: friends or foes?	the unfolded protein response (upr) is a cytoprotective response that is aimed at restoring cellular homeostasis following physiological stress exerted on the endoplasmic reticulum (er), which also invokes innate immune signalling in response to invading microorganisms. although it has been known for some time that the upr is modulated by various viruses, recent evidence indicates that it also has multiple roles during bacterial infections. in this review, we describe how bacteria interact with ...	2014	25534809
bacteria, the endoplasmic reticulum and the unfolded protein response: friends or foes?	the unfolded protein response (upr) is a cytoprotective response that is aimed at restoring cellular homeostasis following physiological stress exerted on the endoplasmic reticulum (er), which also invokes innate immune signalling in response to invading microorganisms. although it has been known for some time that the upr is modulated by various viruses, recent evidence indicates that it also has multiple roles during bacterial infections. in this review, we describe how bacteria interact with ...	2014	25534809
a new oligonucleotide microarray for detection of pathogenic and non-pathogenic legionella spp.	legionella pneumophila has been recognized as the major cause of legionellosis since the discovery of the deadly disease. legionella spp. other than l. pneumophila were later found to be responsible to many non-pneumophila infections. the non-l. pneumophila infections are likely under-detected because of a lack of effective diagnosis. in this report, we have sequenced the 16s-23s rrna gene internal transcribed spacer (its) of 10 legionella species and subspecies, including l. anisa, l. bozemanii ...	2014	25469776
comparative analyses of legionella species identifies genetic features of strains causing legionnaires' disease.	the genus legionella comprises over 60 species. however, l. pneumophila and l. longbeachae alone cause over 95% of legionnaires’ disease. to identify the genetic bases underlying the different capacities to cause disease we sequenced and compared the genomes of l. micdadei, l. hackeliae and l. fallonii (llap10), which are all rarely isolated from humans.	2014	25370836
gene flow in environmental legionella pneumophila leads to genetic and pathogenic heterogeneity within a legionnaires' disease outbreak.	legionnaires' disease is a severe form of pneumonia caused by the environmental bacterium legionella pneumophila. outbreaks commonly affect people with known risk factors, but the genetic and pathogenic complexity of l. pneumophila within an outbreak is not well understood. here, we investigate the etiology of the major legionnaires' disease outbreak that occurred in edinburgh, uk, in 2012, by examining the evolutionary history, genome content, and virulence of l. pneumophila clinical isolates.	2014	25370747
intragenic recombination has a critical role on the evolution of legionella pneumophila virulence-related effector sidj.	sidj is a dot/icm effector involved in the trafficking or retention of er-derived vesicles to legionella pneumophila vacuoles whose mutation causes an observable growth defect, both in macrophage and amoeba hosts. given the crucial role of this effector in l. pneumophila virulence we investigated the mechanisms shaping its molecular evolution. the alignment of sidj sequences revealed several alleles with amino acid variations that may influence the protein properties. the identification of hgt e ...	2014	25299187
the legionella longbeachae icm/dot substrate sidc selectively binds phosphatidylinositol 4-phosphate with nanomolar affinity and promotes pathogen vacuole-endoplasmic reticulum interactions.	legionella spp. cause the severe pneumonia legionnaires' disease. the environmental bacteria replicate intracellularly in free-living amoebae and human alveolar macrophages within a distinct, endoplasmic reticulum (er)-derived compartment termed the legionella-containing vacuole (lcv). lcv formation requires the bacterial icm/dot type iv secretion system (t4ss) that translocates into host cells a plethora of different "effector" proteins, some of which anchor to the pathogen vacuole by binding t ...	2014	25024371
coexistence of legionella pneumophila bacteria and free-living amoebae in lakes serving as a cooling system of a power plant.	the study was aimed at determining whether potentially pathogenic free-living amoebae (fla) and legionella pneumophila can be found in lakes serving as a natural cooling system of a power plant. water samples were collected from five lakes forming the cooling system of the power plants pątnów and konin (poland). the numbers of investigated organisms were determined with the use of a very sensitive molecular method-fluorescence in situ hybridization (fish). the result of the present study shows t ...	2014	25132694
implementing hospital-based surveillance for severe acute respiratory infections caused by influenza and other respiratory pathogens in new zealand.	recent experience with pandemic influenza a(h1n1)pdm09 highlighted the importance of global surveillance for severe respiratory disease to support pandemic preparedness and seasonal influenza control. improved surveillance in the southern hemisphere is needed to provide critical data on influenza epidemiology, disease burden, circulating strains and effectiveness of influenza prevention and control measures. hospital-based surveillance for severe acute respiratory infection (sari) cases was esta ...	2014	25077034
the bacterial aetiology of adult community-acquired pneumonia in asia: a systematic review.	community-acquired pneumonia (cap) is a major cause of adult mortality in asia. appropriate empirical treatment depends on knowledge of the pathogens commonly responsible. however, assessing the aetiological significance of identified organisms is often difficult, particularly with sputum isolates that might represent contamination with oropharyngeal flora.	2014	24781376
genomic diversification in strains of rickettsia felis isolated from different arthropods.	rickettsia felis (alphaproteobacteria: rickettsiales) is the causative agent of an emerging flea-borne rickettsiosis with worldwide occurrence. originally described from the cat flea, ctenocephalides felis, recent reports have identified r. felis from other flea species, as well as other insects and ticks. this diverse host range for r. felis may indicate an underlying genetic variability associated with host-specific strains. accordingly, to determine a potential genetic basis for host speciali ...	2014	25477419
genomic diversification in strains of rickettsia felis isolated from different arthropods.	rickettsia felis (alphaproteobacteria: rickettsiales) is the causative agent of an emerging flea-borne rickettsiosis with worldwide occurrence. originally described from the cat flea, ctenocephalides felis, recent reports have identified r. felis from other flea species, as well as other insects and ticks. this diverse host range for r. felis may indicate an underlying genetic variability associated with host-specific strains. accordingly, to determine a potential genetic basis for host speciali ...	2014	25477419
multiplex real-time pcr assay for detection and differentiation of bordetella pertussis and bordetella parapertussis.	rapid diagnosis of pertussis is important for the timely isolation of the infection source and early prevention measures among the contact persons, especially among non-vaccinated infants for whom pertussis is life-threatening.	2014	25870746
correlation between acrb trimer association affinity and efflux activity.	the majority of membrane proteins function as oligomers. however, it remains largely unclear how the oligomer stability of protein complexes correlates with their function. understanding the relationship between oligomer stability and activity is essential to protein research and to virtually all cellular processes that depend on the function of protein complexes. proteins make lasting or transient interactions as they perform their functions. obligate oligomeric proteins exist and function excl ...	2014	24854514
etiologies and resistance profiles of bacterial community-acquired pneumonia in cambodian and neighboring countries' health care settings: a systematic review (1995 to 2012).	community-acquired pneumonia (cap) is one of the most important causes of morbidity and mortality worldwide. etiological data for cambodia is scarce. we aimed to describe the main etiological agents causing cap, and their resistance patterns in cambodia and the greater mekong region.	2014	24626053
combined proteomic and transcriptomic interrogation of the venom gland of conus geographus uncovers novel components and functional compartmentalization.	cone snails are highly successful marine predators that use complex venoms to capture prey. at any given time, hundreds of toxins (conotoxins) are synthesized in the secretory epithelial cells of the venom gland, a long and convoluted organ that can measure 4 times the length of the snail's body. in recent years a number of studies have begun to unveil the transcriptomic, proteomic and peptidomic complexity of the venom and venom glands of a number of cone snail species. by using a combination o ...	2014	24478445
ards with septic shock due to legionella longbeachae pneumonia in a patient with polymyalgia rheumatica.	legionella longbeachae is a very uncommon cause of community acquired pneumonia in western countries. l. longbeachae does not grow on blood agar media and is usually not detected by sputum gram stain or blood culture. furthermore legionella urinary antigen testing fails to detect it. in this report we described a 79-year-old man with polymyalgia rheumatica under systemic corticosteroid treatment without other additional risk factors who developed a cultured-proven l. longbeachae community-acquir ...	2014	25024993
isolation and expression analysis of novel silicon absorption gene from roots of mangrove (rhizophora apiculata) via suppression subtractive hybridization.	silicon (si) is the second most abundant element in soil after oxygen. it is not an essential element for plant growth and formation but plays an important role in increasing plant tolerance towards different kinds of abiotic and biotic stresses. the molecular mechanism of si absorption and accumulation may differ between plants, such as monocotyledons and dicotyledons. silicon absorption and accumulation in mangrove plants are affected indirectly by some proteins rich in serine and proline amin ...	2014	24516858
contrasting effects of singlet oxygen and hydrogen peroxide on bacterial community composition in a humic lake.	light excitation of humic matter generates reactive oxygen species (ros) in surface waters of aquatic ecosystems. abundant ros generated in humic matter rich lakes include singlet oxygen ((1)o2) and hydrogen peroxide (h2o2). because these ros differ in half-life time and toxicity, we compared their effects on microbial activity ((14)c-leucine incorporation) and bacterial community composition (bcc) in surface waters of humic lake grosse fuchskuhle (north-eastern germany). for this purpose, exper ...	2014	24667441
legionnaires' disease caused by legionella longbeachae in taiwan, 2006-2010.	the aim of the present study was to investigate the epidemiology of legionnaires' disease (ld) caused by legionella longbeachae in taiwan during 2006-2010. a total of six cases were identified prospectively, accounting for 1.6% of all laboratory-confirmed ld cases and 4.4% of culture-positive ld cases. all six cases occurred between april and august. the male to female ratio was 0.5. these six ld patients had a higher median age than those with ld due to legionella pneumophila. four of the six p ...	2014	24269651
legionella spp. in uk composts--a potential public health issue?	over the past 5 years, a number of cases of legionellosis in scotland have been associated with compost use; however, studies investigating sources of infection other than water systems remain limited. this study delivers the first comprehensive survey of composts commonly available in the uk for the presence of legionella species. twenty-two store-bought composts, one green-waste compost and one home-made compost were tested for legionella by culture methods on bcye-α medium, and the findings w ...	2014	24165476
ocular involvement in a patient with legionella longbeachae 1 infection.		2014	24650007
compost and legionella longbeachae: an emerging infection?	human disease caused by legionella species is dominated by legionella pneumophila, the main causative agent in cases of legionnaires' disease. however, other species are known to cause infection, for example, legionella longbeachae causes an equivalent number of cases of disease as l. pneumophila in australia and new zealand. infection with l. longbeachae is commonly associated with exposure to composts and potting soils, and cases of infection with this organism have been increasing in europe o ...	2015	26543151
detection of novel chlamydiae and legionellales from human nasal samples of healthy volunteers.	chlamydiae are intracellular bacterial parasites of eukaryotes, ranging from amoebae to humans. they comprise many novel members and are investigated as emerging pathogens. environmental studies highlighted similarities between the ecologies of chlamydiae and legionellae, both groups being important agents of respiratory infections. herein, we analyzed nasal samples from healthy persons, searching for the presence of amoebae, chlamydiae and legionellae. from a total of 25 samples, we recovered b ...	2015	25697709
cutaneous legionella longbeachae infection in immunosuppressed woman, united kingdom.	we report a rare case of cutaneous legionella longbeachae infection in a patient receiving long-term corticosteroids for immune thrombocytopenia. such infections cannot be identified by using legionella urinary antigen testing but are commonly seen after exposure to commercial potting compost, particularly in immunocompromised patients.	2015	26197048
legionellosis outbreak associated with a hotel fountain.	background. in august 2012, the chicago department of public health (cdph) was notified of acute respiratory illness, including 1 fatality, among a group of meeting attendees who stayed at a chicago hotel during july 30-august 3, 2012. suspecting legionnaires' disease (ld), cdph advised the hotel to close their swimming pool, spa, and decorative lobby fountain and began an investigation. methods. case finding included notification of individuals potentially exposed during july 16-august 15, 20 ...	2015	26716104
exploiting the ubiquitin and phosphoinositide pathways by the legionella pneumophila effector, sidc.	intracellular bacterial pathogens use secreted effector proteins to alter host cellular processes, with the goal of subverting host defenses and allowing the infection to progress. one such pathogen, legionella pneumophila, secretes ~300 proteins into its host to alter a number of pathways including intracellular trafficking, phosphoinositide metabolism, and cell signaling. the legionella effector sidc was previously found to bind to pi(4)p and was responsible for the enrichment of er proteins a ...	2015	26433729
exploiting the ubiquitin and phosphoinositide pathways by the legionella pneumophila effector, sidc.	intracellular bacterial pathogens use secreted effector proteins to alter host cellular processes, with the goal of subverting host defenses and allowing the infection to progress. one such pathogen, legionella pneumophila, secretes ~300 proteins into its host to alter a number of pathways including intracellular trafficking, phosphoinositide metabolism, and cell signaling. the legionella effector sidc was previously found to bind to pi(4)p and was responsible for the enrichment of er proteins a ...	2015	26433729
short-term and long-term survival and virulence of legionella pneumophila in the defined freshwater medium fraquil.	legionella pneumophila (lp) is the etiological agent responsible for legionnaires' disease, a potentially fatal pulmonary infection. lp lives and multiplies inside protozoa in a variety of natural and man-made water systems prior to human infection. fraquil, a defined freshwater medium, was used as a highly reproducible medium to study the behaviour of lp in water. adopting a reductionist approach, fraquil was used to study the impact of temperature, ph and trace metal levels on the survival and ...	2015	26406895
subversion of cell-autonomous immunity and cell migration by legionella pneumophila effectors.	bacteria trigger host defense and inflammatory processes, such as cytokine production, pyroptosis, and the chemotactic migration of immune cells toward the source of infection. however, a number of pathogens interfere with these immune functions by producing specific so-called "effector" proteins, which are delivered to host cells via dedicated secretion systems. air-borne legionella pneumophila bacteria trigger an acute and potential fatal inflammation in the lung termed legionnaires' disease. ...	2015	26441958
utility of pcr, culture, and antigen detection methods for diagnosis of legionellosis.	the goal of this retrospective study was to evaluate the performance of different diagnostic tests for legionnaires' disease in a clinical setting where legionella pneumophila pcr had been introduced. electronic medical records at the cleveland clinic were searched for legionella urinary antigen (uag), culture, and pcr tests ordered from march 2010 through december 2013. for cases where two or more test methods were performed and at least one was positive, the medical record was reviewed for rel ...	2015	26292304
effect of common drinking water disinfectants, chlorine and heat, on free legionella and amoebae-associated legionella.	chlorine and thermal treatments are the most commonly used procedures to control and prevent legionella proliferation in drinking water systems of large buildings. however, cases of legionellosis still occur in facilities with treated water. the purpose of this work was to model the effect of temperature and free chlorine applied in similar exposure conditions as in drinking water systems on five legionella spp. strains and two amoebal strains of the genera acanthamoeba. inactivation models obta ...	2015	26241039
legionellosis on the rise: a review of guidelines for prevention in the united states.	reported cases of legionellosis more than tripled between 2001 and 2012 in the united states. the disease results primarily from exposure to aerosolized water contaminated with legionella.	2015	25203696
dot/icm effector translocation by legionella longbeachae creates a replicative vacuole similar to that of legionella pneumophila despite translocation of distinct effector repertoires.	legionella organisms are environmental bacteria and accidental human pathogens that can cause severe pneumonia, termed legionnaires' disease. these bacteria replicate within a pathogen-derived vacuole termed the legionella-containing vacuole (lcv). our understanding of the development and dynamics of this vacuole is based on extensive analysis of legionella pneumophila. here, we have characterized the legionella longbeachae replicative vacuole (longbeachae-lcv) and demonstrated that, despite imp ...	2015	26216429
isothermal detection of mycoplasma pneumoniae directly from respiratory clinical specimens.	mycoplasma pneumoniae is a leading cause of community-acquired pneumonia (cap) across patient populations of all ages. we have developed a loop-mediated isothermal amplification (lamp) assay that enables rapid, low-cost detection of m. pneumoniae from nucleic acid extracts and directly from various respiratory specimen types. the assay implements calcein to facilitate simple visual readout of positive results in approximately 1 h, making it ideal for use in primary care facilities and resource-p ...	2015	26179304
the tetracycline destructases: a novel family of tetracycline-inactivating enzymes.	enzymes capable of inactivating tetracycline are paradoxically rare compared with enzymes that inactivate other natural-product antibiotics. we describe a family of flavoenzymes, previously unrecognizable as resistance genes, which are capable of degrading tetracycline antibiotics. from soil functional metagenomic selections, we discovered nine genes that confer high-level tetracycline resistance by enzymatic inactivation. we also demonstrate that a tenth enzyme, an uncharacterized homolog in th ...	2015	26097034
rash, disseminated intravascular coagulation and legionella: episode 10 and a rewind into the past.	legionella pneumophila is the most common cause of legionellosis and is one of the organisms causing atypical pneumonia. we report the presentation of disseminated intravascular coagulation (dic) and skin rash in a single case of severe legionella pneumonia. the unique clinical presentation of a diffuse rash diagnosed as purpura fulminans and the unpredictable variations encountered during the diagnostic work-up of the case make this write-up crucial. this article synthesizes all reported cases ...	2015	26236615
microbiological and clinical studies of legionellosis in 33 patients with cancer.	legionella, a large group of environmental gram-negative bacteria, represents an occasional cause of pneumonia. we analyzed the microbiological and clinical features of 33 consecutive cases of legionella infections that occurred at the university of texas md anderson cancer center, houston, tx, from 2002 to 2014. the legionella strains were isolated from bronchoscopy specimens (32 strains) and a blood culture (1 strain) and were identified by sequencing analysis of the full-length 16s rrna gene. ...	2015	25926494
lpg0393 of legionella pneumophila is a guanine-nucleotide exchange factor for rab5, rab21 and rab22.	legionella pneumophila, a human intracellular pathogen, encodes about 290 effector proteins that are translocated into host cells through a secretion machinery. some of these proteins have been shown to manipulate or subvert cellular processes during infection, but functional roles of a majority of them remain unknown. lpg0393 is a newly identified legionella effector classified as a hypothetical protein. through x-ray crystallographic analysis, we show that lpg0393 contains a vps9-like domain, ...	2015	25821953
structural insight into how bacteria prevent interference between multiple divergent type iv secretion systems.	prokaryotes use type iv secretion systems (t4sss) to translocate substrates (e.g., nucleoprotein, dna, and protein) and/or elaborate surface structures (i.e., pili or adhesins). bacterial genomes may encode multiple t4sss, e.g., there are three functionally divergent t4sss in some bartonella species (vir, vbh, and trw). in a unique case, most rickettsial species encode a t4ss (rvh) enriched with gene duplication. within single genomes, the evolutionary and functional implications of cross-system ...	2015	26646013
an update on iron acquisition by legionella pneumophila: new pathways for siderophore uptake and ferric iron reduction.	iron acquisition is critical for the growth and pathogenesis of legionella pneumophila, the causative agent of legionnaires' disease. l. pneumophila utilizes two main modes of iron assimilation, namely ferrous iron uptake via the feob system and ferric iron acquisition through the action of the siderophore legiobactin. this review highlights recent studies concerning the mechanism of legiobactin assimilation, the impact of c-type cytochromes on siderophore production, the importance of legiobact ...	2015	26000653
a side by side comparison of bruker biotyper and vitek ms: utility of maldi-tof ms technology for microorganism identification in a public health reference laboratory.	matrix-assisted laser desorption ionization-time of flight mass spectrometry (maldi-tof ms) has emerged as a rapid, highly accurate, and cost-effective method for routine identification of a wide range of microorganisms. we carried out a side by side comparative evaluation of the performance of bruker biotyper versus vitek ms for identification of a large and diverse collection of microorganisms. most difficult and/or unusual microorganisms, as well as commonly encountered microorganisms were se ...	2015	26658918
relationship between heat-labile enterotoxin secretion capacity and virulence in wild type porcine-origin enterotoxigenic escherichia coli strains.	heat-labile enterotoxin (lt) is an important virulence factor secreted by some strains of enterotoxigenic escherichia coli (etec). the prototypic human-origin strain h10407 secretes lt via a type ii secretion system (t2ss). we sought to determine the relationship between the capacity to secrete lt and virulence in porcine-origin wild type (wt) etec strains. sixteen wt etec strains isolated from cases of severe diarrheal disease were analyzed by gm1ganglioside enzyme-linked immunosorbent assay to ...	2015	25768732
marine amoebae with cytoplasmic and perinuclear symbionts deeply branching in the gammaproteobacteria.	amoebae play an important ecological role as predators in microbial communities. they also serve as niche for bacterial replication, harbor endosymbiotic bacteria and have contributed to the evolution of major human pathogens. despite their high diversity, marine amoebae and their association with bacteria are poorly understood. here we describe the isolation and characterization of two novel marine amoebae together with their bacterial endosymbionts, tentatively named 'candidatus occultobacter ...	2015	26303516
a coxiella-like endosymbiont is a potential vitamin source for the lone star tick.	amblyomma americanum (lone star tick) is an important disease vector in the united states. it transmits several human pathogens, including the agents of human monocytic ehrlichiosis, tularemia, and southern tick-associated rash illness. blood-feeding insects (class insecta) depend on bacterial endosymbionts to provide vitamins and cofactors that are scarce in blood. it is unclear how this deficiency is compensated in ticks (class arachnida) that feed exclusively on mammalian blood. a bacterium r ...	2015	25618142
the eukaryotic translation initiation regulator cdc123 defines a divergent clade of atp-grasp enzymes with a predicted role in novel protein modifications.	deciphering the origin of uniquely eukaryotic features of sub-cellular systems, such as the translation apparatus, is critical in reconstructing eukaryogenesis. one such feature is the highly conserved, but poorly understood, eukaryotic protein cdc123, which regulates the abundance of the eukaryotic translation initiation eif2 complex and binds one of its components eif2γ. we show that the eukaryotic protein cdc123 defines a novel clade of atp-grasp enzymes distinguished from all other members o ...	2015	25976611
trypanosoma cruzi differentiates and multiplies within chimeric parasitophorous vacuoles in macrophages coinfected with leishmania amazonensis.	the trypanosomatids leishmania amazonensis and trypanosoma cruzi are excellent models for the study of the cell biology of intracellular protozoan infections. after their uptake by mammalian cells, the parasitic protozoan flagellates l. amazonensis and t. cruzi lodge within acidified parasitophorous vacuoles (pvs). however, whereas l. amazonensis develops in spacious, phagolysosome-like pvs that may enclose numerous parasites, t. cruzi is transiently hosted within smaller vacuoles from which it ...	2016	26975994
molecular detection of acanthamoeba spp., naegleria fowleri and vermamoeba (hartmannella) vermiformis as vectors for legionella spp. in untreated and solar pasteurized harvested rainwater.	legionella spp. employ multiple strategies to adapt to stressful environments including the proliferation in protective biofilms and the ability to form associations with free-living amoeba (fla). the aim of the current study was to identify legionella spp., acanthamoeba spp., vermamoeba (hartmannella) vermiformis and naegleria fowleri that persist in a harvested rainwater and solar pasteurization treatment system.	2016	27724947
coxiella detection in ticks from wildlife and livestock in malaysia.	recent studies have shown that ticks harbor coxiella-like bacteria, which are potentially tick-specific endosymbionts. we recently described the detection of coxiella-like bacteria and possibly coxiella burnetii in ticks found from rural areas in malaysia. in the present study, we collected ticks, including haemaphysalis bispinosa, haemaphysalis hystricis, dermacentor compactus, dermacentor steini, and amblyomma sp. from wildlife and domesticated goats from four different locations in malaysia. ...	2016	27763821
mechanistic insights into c-di-gmp-dependent control of the biofilm regulator fleq from pseudomonas aeruginosa.	bacterial biofilm formation during chronic infections confers increased fitness, antibiotic tolerance, and cytotoxicity. in many pathogens, the transition from a planktonic lifestyle to collaborative, sessile biofilms represents a regulated process orchestrated by the intracellular second-messenger c-di-gmp. a main effector for c-di-gmp signaling in the opportunistic pathogen pseudomonas aeruginosa is the transcription regulator fleq. fleq is a bacterial enhancer-binding protein (bebp) with a ce ...	2016	26712005
mechanistic insights into c-di-gmp-dependent control of the biofilm regulator fleq from pseudomonas aeruginosa.	bacterial biofilm formation during chronic infections confers increased fitness, antibiotic tolerance, and cytotoxicity. in many pathogens, the transition from a planktonic lifestyle to collaborative, sessile biofilms represents a regulated process orchestrated by the intracellular second-messenger c-di-gmp. a main effector for c-di-gmp signaling in the opportunistic pathogen pseudomonas aeruginosa is the transcription regulator fleq. fleq is a bacterial enhancer-binding protein (bebp) with a ce ...	2016	26712005
diverse mechanisms of metaeffector activity in an intracellular bacterial pathogen, legionella pneumophila.	pathogens deliver complex arsenals of translocated effector proteins to host cells during infection, but the extent to which these proteins are regulated once inside the eukaryotic cell remains poorly defined. among all bacterial pathogens, legionella pneumophila maintains the largest known set of translocated substrates, delivering over 300 proteins to the host cell via its type ivb, icm/dot translocation system. backed by a few notable examples of effector-effector regulation in l. pneumophila ...	2016	27986836
mtor-driven metabolic reprogramming regulates legionella pneumophila intracellular niche homeostasis.	vacuolar bacterial pathogens are sheltered within unique membrane-bound organelles that expand over time to support bacterial replication. these compartments sequester bacterial molecules away from host cytosolic immunosurveillance pathways that induce antimicrobial responses. the mechanisms by which the human pulmonary pathogen legionella pneumophila maintains niche homeostasis are poorly understood. we uncovered that the legionella-containing vacuole (lcv) required a sustained supply of host l ...	2016	27942021
legionella shows a diverse secondary metabolism dependent on a broad spectrum sfp-type phosphopantetheinyl transferase.	several members of the genus legionella cause legionnaires' disease, a potentially debilitating form of pneumonia. studies frequently focus on the abundant number of virulence factors present in this genus. however, what is often overlooked is the role of secondary metabolites from legionella. following whole genome sequencing, we assembled and annotated the legionella parisiensis dsm 19216 genome. together with 14 other members of the legionella, we performed comparative genomics and analysed t ...	2016	27904811
presence and persistence of viable, clinically relevant legionella pneumophila bacteria in garden soil in the netherlands.	garden soils were investigated as reservoirs and potential sources of pathogenic legionella bacteria. legionella bacteria were detected in 22 of 177 garden soil samples (12%) by amoebal coculture. of these 22 legionella-positive soil samples, seven contained legionella pneumophila several other species were found, including the pathogenic legionella longbeachae (4 gardens) and legionella sainthelensi (9 gardens). the l. pneumophila isolates comprised 15 different sequence types (sts), and eight ...	2016	27316958
active and adaptive legionella crispr-cas reveals a recurrent challenge to the pathogen.	clustered regularly interspaced short palindromic repeats with crispr-associated gene (crispr-cas) systems are widely recognized as critical genome defense systems that protect microbes from external threats such as bacteriophage infection. several isolates of the intracellular pathogen legionella pneumophila possess multiple crispr-cas systems (type i-c, type i-f and type ii-b), yet the targets of these systems remain unknown. with the recent observation that at least one of these systems (ii-b ...	2016	26936325
determination of viable legionellae in engineered water systems: do we find what we are looking for?	in developed countries, legionellae are one of the most important water-based bacterial pathogens caused by management failure of engineered water systems. for routine surveillance of legionellae in engineered water systems and outbreak investigations, cultivation-based standard techniques are currently applied. however, in many cases culture-negative results are obtained despite the presence of viable legionellae, and clinical cases of legionellosis cannot be traced back to their respective con ...	2016	26928563
legionella pneumophila s1p-lyase targets host sphingolipid metabolism and restrains autophagy.	autophagy is an essential component of innate immunity, enabling the detection and elimination of intracellular pathogens. legionella pneumophila, an intracellular pathogen that can cause a severe pneumonia in humans, is able to modulate autophagy through the action of effector proteins that are translocated into the host cell by the pathogen's dot/icm type iv secretion system. many of these effectors share structural and sequence similarity with eukaryotic proteins. indeed, phylogenetic analyse ...	2016	26831115
two related occupational cases of legionella longbeachae infection, quebec, canada.	two patients with no exposure to gardening compost had related legionella longbeachae infections in quebec, canada. epidemiologic investigation and laboratory results from patient and soil samples identified the patients' workplace, a metal recycling plant, as the likely source of infection, indicating a need to suspect occupational exposure for l. longbeachae infections.	2016	27314946
analysis of bacterial communities associated with potting media.	potting media are commonly used by growers in different parts of the world for potted plants, raising seedlings and for improving soil characteristics. this study was conducted to characterize bacterial communities occurring in 13 commercial potting media products originating from seven countries.	2016	26844021
public health implications of acanthamoeba and multiple potential opportunistic pathogens in roof-harvested rainwater tanks.	a study of six potential opportunistic pathogens (acanthamoeba spp., legionella spp., legionella longbeachae, pseudomonas aeruginosa, mycobacterium avium and mycobacterium intracellulare) and an accidental human pathogen (legionella pneumophila) in 134 roof-harvested rainwater (rhrw) tank samples was conducted using quantitative pcr (qpcr). all five opportunistic pathogens and accidental pathogen l. pneumophila were detected in rainwater tanks except legionella longbeachae. concentrations ranged ...	2016	27336236
simultaneous detection of legionella species and l. anisa, l. bozemanii, l. longbeachae and l. micdadei using conserved primers and multiple probes in a multiplex real-time pcr assay.	legionnaires' disease is a severe respiratory disease that is estimated to cause between 8,000 and 18,000 hospitalizations each year, though the exact burden is unknown due to under-utilization of diagnostic testing. although legionella pneumophila is the most common species detected in clinical cases (80-90%), other species have also been reported to cause disease. however, little is known about legionnaires' disease caused by these non-pneumophila species. we designed a multiplex real-time pcr ...	2016	27107536
molecular diagnosis of legionella infections--clinical utility of front-line screening as part of a pneumonia diagnostic algorithm.	urinary antigen testing for legionella pneumophila serogroup 1 is the leading rapid diagnostic test for legionnaires' disease (ld); however other legionella species and serogroups can also cause ld. the aim was to determine the utility of front-line l. pneumophila and legionella species pcr in a severe respiratory infection algorithm.	2016	26632328
metabolism of myo-inositol by legionella pneumophila promotes infection of amoebae and macrophages.	legionella pneumophila is a natural parasite of environmental amoebae and the causative agent of a severe pneumonia termed legionnaires' disease. the facultative intracellular pathogen employs a bipartite metabolism, where the amino acid serine serves as the major energy supply, while glycerol and glucose are mainly utilized for anabolic processes. the l. pneumophila genome harbors the cluster lpg1653 to lpg1649 putatively involved in the metabolism of the abundant carbohydrate myo-inositol (her ...	2016	27287324
environmental factors affecting the survival of soil dwelling legionella longbeachae in water.	legionella longbeachae, a causative agent of legionnaire's disease, has often been associated with potting soil and gardening, a feature quite distinct from other legionella species. the precise transmission mechanism is still unknown, although due to the ecological coherence of the soil and water there is a potential risk of infection by contaminated stagnant water in the garden.	2016	27660867
legionnaires' disease caused by legionella longbeachae: clinical features and outcomes of 107 cases from an endemic area.	legionella longbeachae is a predominant cause of legionnaires' disease in some parts of the world, particularly in australasia. clinical reports of l. longbeachae infection are limited to case reports or small case series, and culture-confirmed cases.	2016	27199169
a non-fatal pneumonia due to legionella longbeachae in a patient with systemic lupus erythematosus.		2016	27068117
comparison of legionella longbeachae and legionella pneumophila cases in scotland; implications for diagnosis, treatment and public health response.	the reported incidence of legionnaires' disease caused by legionella longbeachae has increased since 2008 in scotland. while microbiological and epidemiological studies have identified exposure to growing media as a risk factor for infection, little is known about the differences regarding disease risk factors, clinical features and outcomes of infection with l. longbeachae when compared with l. pneumophila. a nested case-case study was performed comparing 12 l. longbeachae cases with 25 confirm ...	2016	26704297
incorporating time-dose-response into legionella outbreak models.	a novel method was used to incorporate in vivo host-pathogen dynamics into a new robust outbreak model for legionellosis. dose-response and time-dose-response (tdr) models were generated for legionella longbeachae exposure to mice via the intratracheal route using a maximum likelihood estimation approach. the best-fit tdr model was then incorporated into two l. pneumophila outbreak models: an outbreak that occurred at a spa in japan, and one that occurred in a melbourne aquarium. the best-fit td ...	2017	27228068
legionella longbeachae is immunologically silent and highly virulent in vivo.	legionella longbeachae (llo) and legionella pneumophila (lpn) are the most common pneumonia-causing agents of the genus. although both species can be lethal to humans and are highly prevalent, little is known about the molecular pathogenesis of llo infections. in murine models of infection, lpn infection is self-limited, whereas llo infection is lethal.	2017	27932612