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the legionella pneumophila incomplete phosphotransferase system (pts) is required for optimal intracellular growth and maximal expression of pmra regulated effectors.the nitrogen phosphotransferase system (pts(ntr)) is a regulatory cascade present in many bacteria, where it controls different functions. this system is usually composed of three basic components: ei(ntr), npr and eiia(ntr) (encoded by the ptsp, ptso and ptsn genes, respectively). in legionella pneumophila, as well as in many other legionella species, the eiia(ntr) component is missing. however, we found that deletion mutations in both ptsp and ptso are partially attenuated for intracellular gr ...201728373357
orange sputum in a kidney transplant patient with legionella micdadei pneumonia. 201727133899
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 ...201627107536
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 ...201626712005
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 ...201626712005
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 ...201626936325
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 ...201626928563
nontuberculous mycobacterial ocular infections: a systematic review of the literature.nontuberculous or atypical mycobacterial ocular infections have been increasing in prevalence over the past few decades. they are known to cause periocular, adnexal, ocular surface and intraocular infections and are often recalcitrant to medical therapy. these infections can potentially cause detrimental outcomes, in part due to a delay in diagnosis. we review 174 case reports and series on nontuberculous mycobacterial (ntm) ocular infections and discuss etiology, microbiology, risk factors, dia ...201526106601
brain abscess following rituximab infusion in a patient with pemphigus vulgaris.immunocompromised patients are at increased risk for developing meningitis or, rarely, brain abscess with opportunistic organisms like listeria monocytogenes.201525659437
a nonhuman primate scrub typhus model: protective immune responses induced by pkarp47 dna vaccination in cynomolgus macaques.we developed an intradermal (id) challenge cynomolgus macaque (macaca fascicularis) model of scrub typhus, the leading cause of treatable undifferentiated febrile illness in tropical asia, caused by the obligate intracellular bacterium, orientia tsutsugamushi. a well-characterized animal model is required for the development of clinically relevant diagnostic assays and evaluation of therapeutic agents and candidate vaccines. we investigated scrub typhus disease pathophysiology and evaluated two ...201525601925
oxidative stress control by apicomplexan parasites.apicomplexan parasites cause infectious diseases that are either a severe public health problem or an economic burden. in this paper we will shed light on how oxidative stress can influence the host-pathogen relationship by focusing on three major diseases: babesiosis, coccidiosis, and toxoplasmosis.201525722976
genomic investigation of a legionellosis outbreak in a persistently colonized hotel.a long-lasting legionellosis outbreak was reported between november 2011 and july 2012 in a hotel in calpe (spain) affecting 44 patients including six deaths. intensive epidemiological and microbiological investigations were performed in order to detect the reservoirs.201526834713
genomic investigation of a legionellosis outbreak in a persistently colonized hotel.a long-lasting legionellosis outbreak was reported between november 2011 and july 2012 in a hotel in calpe (spain) affecting 44 patients including six deaths. intensive epidemiological and microbiological investigations were performed in order to detect the reservoirs.201526834713
atypical presentation of legionella pneumonia among patients with underlying cancer: a fifteen-year review.immunocompromised patients, especially those receiving treatment with corticosteroids and cytotoxic chemotherapy are at increased risk for developing legionella pneumonia.201526496794
atypical presentation of legionella pneumonia among patients with underlying cancer: a fifteen-year review.immunocompromised patients, especially those receiving treatment with corticosteroids and cytotoxic chemotherapy are at increased risk for developing legionella pneumonia.201526496794
prevalence and molecular characteristics of waterborne pathogen legionella in industrial cooling tower environments.cooling towers are a source of legionnaires' disease. it is important from a public health perspective to survey industrial cooling towers for the presence of legionella. prospective surveillance of the extent of legionella pollution was conducted at factories in shijiazhuang, china between march 2011 and september 2012. overall, 35.7% of 255 industrial cooling tower water samples showed legionella-positive, and their concentrations ranged from 100 colony-forming units (cfu)/liter to 88,000 cfu/ ...201526473896
legionella micdadei: a forgotten etiology of growing cavitary nodules: a case report and literature review.background. legionella micdadei is a gram negative bacterium that can stain weakly acid fast. it was first described in 1979 after immunosuppressed patients developed pneumonia at a pittsburgh va, initially given the name pittsburgh pneumonia agent. it is the second most common legionella species causing infection after pneumophila, and typically infects immunocompromised hosts. it is not easy to be cultured which makes diagnosing difficult. case presentation. a 31-year-old female with ulcerativ ...201526451267
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 ...201526292304
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 ...201526236615
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. ...201525926494
mistaken identity: legionella micdadei appearing as acid-fast bacilli on lung biopsy of a hematopoietic stem cell transplant patient.legionella micdadei is a potential cause of invasive lung infections in immunocompromised hosts. on biopsy specimens, it can appear as an acid-fast bacillus (afb) and can be mistaken for a member of genus mycobacterium. as legionella requires selective media to grow in culture, and the commonly used, commercially available urine antigen test for legionella only detects legionella pneumophila serogroup-1, but not l. micdadei, it is important to consider this organism in the differential diagnosis ...201525573597
microbial contamination of drinking water and human health from community water systems.a relatively short list of reference viral, bacterial and protozoan pathogens appears adequate to assess microbial risks and inform a system-based management of drinking waters. nonetheless, there are data gaps, e.g. human enteric viruses resulting in endemic infection levels if poorly performing disinfection and/or distribution systems are used, and the risks from fungi. where disinfection is the only treatment and/or filtration is poor, cryptosporidiosis is the most likely enteric disease to b ...201525821716
role of innate t cells in anti-bacterial immunity.innate t cells are a heterogeneous group of αβ and γδ t cells that respond rapidly (<2 h) upon activation. these innate t cells also share a non mhc class i or ii restriction requirement for antigen recognition. three major populations within the innate t cell group are recognized, namely, invariant nkt cells, mucosal associated invariant t cells, and gamma delta t cells. these cells recognize foreign/self-lipid presented by non-classical mhc molecules, such as cd1d, mr1, and cd1a. they are acti ...201526124758
15(th) annual southern hospital medicine conference abstracts. 201525829893
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 ...201526658918
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 ...201425184565
role of brevundimonas vesicularis in supporting the growth of legionella in nutrient-poor environments.in 1986, we encountered the first case of legionella micdadei pneumonia in japan. in the follow-up study to determine the infection route of l. micdadei, we isolated brevundimonas vesicularis from the shower hose of the patient�s home. this motivated us to explore the symbiosis between b. vesicularis and legionella in this study. b. vesicularis type strain, b. vesicularis kobe strain, legionella pneumophila serogroup 1 type strain, and l. micdadei kobe strain were used. b. vesicularis was inocul ...201424531169
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.201425870746
pulmonary infection by rhodococcus equi presenting with positive ziehl-neelsen stain in a patient with human immunodeficiency virus: a case report.patients with human immunodeficiency virus carry a significant risk of contracting opportunistic infections. the worldwide increased incidence of tuberculosis has instituted pulmonary tuberculosis as an important diagnostic consideration in patients with human immunodeficiency virus presenting with lower respiratory tract infection. a positive result on the readily-available ziehl-neelsen stain usually leads to the initiation of antituberculous treatment, since tuberculosis may exert a rapid and ...201425495684
14(th) annual southern hospital medicine conference abstracts. 201424688348
γδ t cells and their potential for immunotherapy.vγ9vδ2 (also termed vγ2vδ2) t cells, a major human peripheral blood γδ t cell subset, recognize microbial (e)-4-hydroxy-3-methylbut-2-enyl diphosphate and endogenous isopentenyl diphosphate in a tcr-dependent manner. the recognition does not require specific accessory cells, antigen uptake, antigen processing, or mhc class i, class ii, or class ib expression. this subset of t cells plays important roles in mediating innate immunity against a wide variety of infections and displays potent and bro ...201424520210
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 ...201425469776
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.201425370836
toxoplasma effector maf1 mediates recruitment of host mitochondria and impacts the host response.recent information has revealed the functional diversity and importance of mitochondria in many cellular processes including orchestrating the innate immune response. intriguingly, several infectious agents, such as toxoplasma, legionella, and chlamydia, have been reported to grow within vacuoles surrounded by host mitochondria. although many hypotheses have been proposed for the existence of host mitochondrial association (hma), the causes and biological consequences of hma have remained unansw ...201424781109
round pneumonia in an elderly woman.we describe a case of pneumococcal round pneumonia in an elderly smoker and it demonstrates the role of inflammatory biomarkers and follow-up imaging in ruling out more ominous diagnoses.201325356230
round pneumonia in an elderly woman.we describe a case of pneumococcal round pneumonia in an elderly smoker and it demonstrates the role of inflammatory biomarkers and follow-up imaging in ruling out more ominous diagnoses.201325356230
high seroprevalence of mycoplasma pneumoniae igm in acute q fever by enzyme-linked immunosorbent assay (elisa).q fever is serologically cross-reactive with other intracellular microorganisms. however, studies of the serological status of mycoplasma pneumoniae and chlamydophila pneumoniae during q fever are rare. we conducted a retrospective serological study of m. pneumoniae and c. pneumoniae by enzyme-linked immunosorbent assay (elisa), a method widely used in clinical practice, in 102 cases of acute q fever, 39 cases of scrub typhus, and 14 cases of murine typhus. the seropositive (57.8%, 7.7%, and 0%, ...201324147043
legionella micdadei brain abscess.we describe an immunocompromised patient who developed a large frontal brain abscess caused by legionella micdadei. this is, to our knowledge, a rare case of culture-proven legionella central nervous system infection.201323224082
development of a dna microarray method for detection and identification of all 15 distinct o-antigen forms of legionella pneumophila.legionella is ubiquitous in many environments. at least 50 species and 70 serogroups of the gram-negative bacterium have been identified. of the 50 species, 20 are pathogenic, and legionella pneumophila is responsible for the great majority (approximately 90%) of the legionnaires' disease cases that occur. furthermore, of the 15 l. pneumophila serogroups identified, o1 alone causes more than 84% of the legionnaires' disease cases that occur worldwide. rapid and reliable assays for the detection ...201323974134
high prevalence, genetic diversity and intracellular growth ability of legionella in hot spring environments.legionella is the causative agent of legionnaires' disease, and hot springs are a major source of outbreaks of this disease. it is important from a public health perspective to survey hot spring environments for the presence of legionella.201323527075
identification of legionella spp. in environmental water samples by scanvit-legionella™ method in spain.rapid and more sensitive methods for the detection and quantification of viable legionella cells have been developed. in this paper, a comparative analysis of environmental water samples using the scanvit-legionella™ method and the traditional "gold standard" method of culturing is realised indicating the usefulness of the scanvit method. the scanvit-legionella™ method was performed on environmental water samples from different locations of huesca region (spain). legionella micro-colonies should ...201324426100
cell extract-containing medium for culture of intracellular fastidious bacteria.the culture of fastidious microorganisms is a critical step in infectious disease studies. as a proof-of-concept experiment, we evaluated an empirical medium containing eukaryotic cell extracts for its ability to support the growth of coxiella burnetii. here, we demonstrate the exponential growth of several bacterial strains, including the c. burnetii nine mile phase i and phase ii strains, and c. burnetii isolates from humans and animals. low-oxygen-tension conditions and the presence of small ...201323740722
rapid pcr detection of mycoplasma hominis, ureaplasma urealyticum, and ureaplasma parvum.objective. we compared laboratory developed real-time pcr assays for detection of mycoplasma hominis and for detection and differentiation of ureaplasma urealyticum and parvum to culture using genitourinary specimens submitted for m. hominis and ureaplasma culture. methods. 283 genitourinary specimens received in the clinical bacteriology laboratory for m. hominis and ureaplasma species culture were evaluated. nucleic acids were extracted using the total nucleic acid kit on the magna pure 2.0. 5 ...201326904723
showers, sweating and suing: legionnaires' disease and 'new' infections in britain, 1977-90.legionnaires' disease is now routinely discussed as an 'emerging infectious disease' (eid) and is said to be one of the earliest such diseases to be recognised. it first appeared in 1976 and its cause was identified in 1977, the same year that ebola fever, hantaan virus and campylobacter jejuni arrived. the designation of legionnaires' disease as an eid was retrospective; it was not and could not be otherwise as the category only gained currency in the early 1990s. in this article we reflect on ...201223752984
legionella micdadei prosthetic valve endocarditis complicated by brain abscess: case report and review of the literature.legionella endocarditis is extremely uncommon, and embolic phenomena have never been reported. we report the first case of legionella micdadei prosthetic valve endocarditis complicated by brain abscess. a 57-y-old immunocompromised woman with a history of mitral valve replacement developed confusion and left-sided weakness. brain magnetic resonance imaging showed a 3-cm peripheral-enhancing mass. transoesophageal echocardiography suggested a perivalvular abscess. blood cultures and valve culture ...201222235842
detection of legionella bozemanae, a new cause of septic arthritis, by pcr followed by specific culture.legionella bozemanae is a rare isolate in clinical specimens. we describe a case of joint infection due to l. bozemanae in an immunocompromised patient with dermatomyositis. without the use of pcr screening or culture on specialized medium, the organism would not have been detected.201223052316
legionnaires' disease caused by legionella londiniensis.legionella londiniensis has been isolated from aqueous environments. however, to our knowledge, this organism has never been isolated from clinical specimens. a case of legionnaires' disease in a hematopoietic stem cell transplant recipient caused by this organism is described, which confirms that l. londiniensis can be an opportunistic pathogen.201223052303
implication of proteins containing tetratricopeptide repeats in conditional virulence phenotypes of legionella pneumophila.legionella pneumophila, the causative agent of legionnaires' disease, is a ubiquitous freshwater bacterium whose virulence phenotypes require a type iv secretion system (t4ss). l. pneumophila strain jr32 contains two virulence-associated t4sss, the dot/icm and lvh t4sss. defective entry and phagosome acidification phenotypes of dot/icm mutants are conditional and reversed by incubating broth-grown stationary-phase cultures in water (ws treatment) prior to infection, as a mimic of the aquatic env ...201222563053
legionella cardiaca sp. nov., isolated from a case of native valve endocarditis in a human heart.a gram-negative, rod-shaped bacterium, designated h63(t), was isolated from aortic valve tissue of a patient with native valve endocarditis. 16s rrna gene sequencing revealed that h63(t) belongs to the genus legionella, with its closest neighbours being the type strains of legionella brunensis (98.8% similarity), l. londiniensis (97.0%), l. jordanis (96.8%), l. erythra (96.2%), l. dresdenensis (96.0%) and l. rubrilucens, l. feeleii, l. pneumophila and l. birminghamensis (95.7%). dna-dna hybridiz ...201222286905
Prediction of the pathogens that are the cause of pneumonia by the battlefield hypothesis.Commensal organisms are frequent causes of pneumonia. However, the detection of these organisms in the airway does not mean that they are the causative pathogens; they may exist merely as colonizers. In up to 50% cases of pneumonia, the causative pathogens remain unidentified, thereby hampering targeting therapies. In speculating on the role of a commensal organism in pneumonia, we devised the battlefield hypothesis. In the "pneumonia battlefield," the organism-to-human cell number ratio may be ...201121909436
the acid phosphatase acpa is secreted in vitro and in macrophages by francisella spp.francisella tularensis is a remarkably infectious facultative intracellular pathogen that causes the zoonotic disease tularemia. essential to f. tularensis spp. pathogenesis is its ability to escape the destructive phagosomal environment and inhibit the host cell respiratory burst. f. tularensis spp. encode a series of acid phosphatases, which have been reported to play important roles in francisella phagosomal escape, inhibition of the respiratory burst and intracellular survival. however, rigo ...201122184418
q fever: current state of knowledge and perspectives of research of a neglected zoonosis.q fever is an ubiquitous zoonosis caused by an resistant intracellular bacterium, coxiella burnetii. in certain areas, q fever can be a severe public health problem, and awareness of the disease must be promoted worldwide. nevertheless, knowledge of coxiella burnetii remains limited to this day. its resistant (intracellular and environmental) and infectious properties have been poorly investigated. further understanding of the interactions between the infected host and the bacteria is necessary. ...201122194752
identification of legionella pneumophila serogroups and other legionella species by mip gene sequencing.the virulence factor known as the macrophage infectivity potentiator (mip) is responsible for the intracellular survival of legionella species. in this study, we investigated the potential of the mip gene sequence to differentiate isolates of different species of legionella and different serogroups of legionella pneumophila. we used 35 clinical l. pneumophila isolates and one clinical isolate each of legionella micdadei, legionella longbeachae, and legionella dumoffii (collected from hospitals a ...201122015397
the occurrence of legionella species other than legionella pneumophila in clinical and environmental samples in denmark identified by mip gene sequencing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry.clin microbiol infect abstract: in denmark, several laboratories use pcr as a routine diagnostic method for legionnaires' disease, and almost all pcr-positive samples are investigated by culture. from 1993 to 2010, isolates of legionella species other than legionella pneumophila were obtained from respiratory samples from 33 patients, and from 1997 to 2010, 42 isolates of legionella non-pneumophila species were obtained and saved from water samples from 39 different sites in denmark. macrophage ...201122070605
the surfactant of legionella pneumophila is secreted in a tolc-dependent manner and is antagonistic toward other legionella species.when legionella pneumophila grows on agar plates, it secretes a surfactant that promotes flagellum- and pilus-independent "sliding" motility. we isolated three mutants that were defective for surfactant. the first two had mutations in genes predicted to encode cytoplasmic enzymes involved in lipid metabolism. these genes mapped to two adjacent operons that we designated bbcabcdef and bbcghijk. backcrossing and complementation confirmed the importance of the bbc genes and suggested that the legio ...201121890700
Analytical performance of the Roche LightCycler® Mycobacterium Detection Kit for the diagnosis of clinically important mycobacterial species.The LightCycler® Mycobacterium Detection Kit based on real-time PCR technology for the detection of Mycobacterium tuberculosis, Mycobacterium avium and Mycobacterium kansasii was recently developed. This study evaluated its analytical sensitivity, specificity and reproducibility.201121961045
activities of tigecycline and comparators against legionella pneumophila and legionella micdadei extracellularly and in human monocyte-derived macrophages.the activity of tigecycline against legionellae, which are intracellular pathogens, was evaluated intracellularly in human phagocytes and extracellularly, and compared to the activities of erythromycin and levofloxacin. clinical isolates of l. pneumophila serogroups 1, 5, and 6 and l. micdadei were tested in time-kill experiments. extracellular experiments were done using buffered yeast extract broth. for intracellular assays, monolayers of human monocyte-derived macrophages (mdm) were infected ...201121146719
in vitro antibacterial activity of modithromycin, a novel 6,11-bridged bicyclolide, against respiratory pathogens, including macrolide-resistant gram-positive cocci.the in vitro activities of modithromycin against gram-positive and -negative respiratory pathogens, including macrolide-resistant cocci with different resistance mechanisms, were compared with those of other macrolide and ketolide agents. mics were determined by the broth microdilution method. all 595 test strains used in this study were isolated from japanese medical facilities. the erm (ribosome methylase) and/or mef (efflux pump) gene, which correlated with resistance to erythromycin as well ...201121220534
pcr methods for the rapid detection and identification of four pathogenic legionella spp. and two legionella pneumophila subspecies based on the gene amplification of gyrb.a total of 25 gyrb gene sequences from 20 legionella pneumophila subsp. pneumophila strains and five l. pneumophila subsp. fraseri strains were obtained and analyzed, and a multiplex pcr for the simultaneous detection of legionella bozemanae, legionella longbeachae, legionella micdadei and legioenella pneumophila, and two single pcrs for the differentiation of l. pneumophila subsp. pneumophila and l. pneumophila subsp. fraseri were established. the multiplex pcr method was shown to be highly spe ...201121626022
proteomics paves the way for q fever diagnostics.abstract: q fever is a worldwide zoonosis caused by coxiella burnetii. the disease most frequently manifests clinically as a self-limited febrile illness, as pneumonia (acute q fever) or as a chronic illness that presents mainly as infective endocarditis. the extreme infectivity of the bacterium results in large outbreaks, and the recent outbreak in the netherlands underlines its impact on public health. recent studies on the bacterium have included genome sequencing, the investigation of host-b ...201121801463
legionella micdadei, a new cause of prosthetic joint infection.extrapulmonary infections caused by legionella spp. other than legionella pneumophila are rare. we report what is, to our knowledge, the first description of a prosthetic joint infection due to legionella spp. systematic testing of samples with suspected prosthetic infection by molecular biology techniques was essential. legionella micdadei should be added to the list of microorganisms causing prosthetic joint infection.201121715591
circadian clock proteins in prokaryotes: hidden rhythms?circadian clock genes are vital features of eukaryotes that have evolved such that organisms can adapt to our planet's rotation in order to anticipate the coming day or night as well as unfavorable seasons. this circadian clock uses oscillation as a timekeeping element. however, circadian clock mechanisms exist also in prokaryotes. the circadian clock of cyanobacteria is well studied. it is regulated by a cluster of three genes: kaia, kaib, and kaic. in this review, we will discuss the circadian ...201021687756
microfluidic platform versus conventional real-time polymerase chain reaction for the detection of mycoplasma pneumoniae in respiratory specimens.rapid, accurate diagnosis of community-acquired pneumonia (cap) due to mycoplasma pneumoniae is compromised by low sensitivity of culture and serology. polymerase chain reaction (pcr) has emerged as a sensitive method to detect m. pneumoniae dna in clinical specimens. however, conventional real-time pcr is not cost-effective for routine or outpatient implementation. here, we evaluate a novel microfluidic real-time pcr platform (advanced liquid logic, research triangle park, nc) that is rapid, po ...201020227222
stress-induced synthesis of phosphatidylinositol 3-phosphate in mycobacteria.phosphoinositides play key roles in regulating membrane dynamics and intracellular signaling in eukaryotic cells. however, comparable lipid-based signaling pathways have not been identified in bacteria. here we show that mycobacterium smegmatis and other actinomycetes bacteria can synthesize the phosphoinositide, phosphatidylinositol 3-phosphate (pi3p). this lipid was transiently labeled with [(3)h]inositol. sensitivity of the purified lipid to alkaline phosphatase, headgroup analysis by high-pr ...201020364020
exploitation of conserved eukaryotic host cell farnesylation machinery by an f-box effector of legionella pneumophila.farnesylation involves covalent linkage of eukaryotic proteins to a lipid moiety to anchor them into membranes, which is essential for the biological function of ras and other proteins. a large cadre of bacterial effectors is injected into host cells by intravacuolar pathogens through elaborate type iii-vii translocation machineries, and many of these effectors are incorporated into the pathogen-containing vacuolar membrane by unknown mechanisms. the dot/icm type iv secretion system of legionell ...201020660614
distribution of legionella species from environmental water sources of public facilities and genetic diversity of l. pneumophila serogroup 1 in south korea.a total of 560 legionella species were isolated from environmental water sources from public facilities from june to september 2008 throughout south korea. the distribution of legionella isolates was investigated according to geographical region, facility type, and sample type. the genetic diversity of 104 isolates of legionella pneumophila serogroup 1 (sg 1) was analyzed by sequence-based typing (sbt). l. pneumophila was distributed broadly throughout korea, accounting for 85.0% of the isolates ...201020693456
legionella pneumophila strain 130b possesses a unique combination of type iv secretion systems and novel dot/icm secretion system effector proteins.legionella pneumophila is a ubiquitous inhabitant of environmental water reservoirs. the bacteria infect a wide variety of protozoa and, after accidental inhalation, human alveolar macrophages, which can lead to severe pneumonia. the capability to thrive in phagocytic hosts is dependent on the dot/icm type iv secretion system (t4ss), which translocates multiple effector proteins into the host cell. in this study, we determined the draft genome sequence of l. pneumophila strain 130b (wadsworth). ...201020833813
rifampin combination therapy for nonmycobacterial infections.the increasing emergence of antimicrobial-resistant organisms, especially methicillin-resistant staphylococcus aureus (mrsa), has resulted in the increased use of rifampin combination therapy. the data supporting rifampin combination therapy in nonmycobacterial infections are limited by a lack of significantly controlled clinical studies. therefore, its current use is based upon in vitro or in vivo data or retrospective case series, all with major limitations. a prominent observation from this r ...201020065324
dual detection of legionella pneumophila and legionella species by real-time pcr targeting the 23s-5s rrna gene spacer region.although the majority of cases of legionnaires' disease (ld) are caused by legionella pneumophila, an increasing number of other legionella species have been reported to cause human disease. there are no clinical presentations unique to ld and hence accurate laboratory tests are required for early diagnosis. therefore, we designed a real-time pcr assay that targets the 23s-5s rrna intergenic spacer region (23s-5s pcr) and allows for detection of all legionella species and discrimination of l. pn ...201019438641
compost facilities as a reservoir of legionella pneumophila and other legionella species.data on the presence of legionellae outside the aquatic environment are scarce. alternative ecosystems that could act as a reservoir for legionella spp. have been investigated to identify unconventional contaminated substrates that are able to produce bioaerosols. we considered eight green waste collection sites including three composting facilities. legionella pneumophila sg 1-15, legionella bozemanii, legionella cincinnatiensis, legionella jamestowniensis, legionella micdadei and l. oakridgens ...201019645762
growth in acanthamoeba sp. and antibiotic susceptibility of legionella micdadei isolated from hot spring water samples.as part of an epidemiological study on legionellosis, we attempted to isolate legionella spp. from hot spring water samples, and were able to isolate legionella micdadei from 3 (5.5%) of 55 samples. all of these isolates were able to grow within acanthamoeba sp., suggesting that the isolates will be pathogens. we also confirmed that the k-2 strain from hot spring water grew in guinea pig monocytes. sensitivity tests using 10 drugs showed that the isolates were most sensitive to imipenem, with th ...200920055224
potentially pathogenic bacteria in shower water and air of a stem cell transplant unit.potential pathogens from shower water and aerosolized shower mist (i.e., shower aerosol) have been suggested as an environmental source of infection for immunocompromised patients. to quantify the microbial load in shower water and aerosol samples, we used culture, microscopic, and quantitative pcr methods to investigate four shower stalls in a stem cell transplant unit at barnes-jewish hospital in st. louis, mo. we also tested membrane-integrated showerheads as a possible mitigation strategy. i ...200919581474
phagocytosis inhibits f-actin-enriched membrane protrusions stimulated by fractalkine (cx3cl1) and colony-stimulating factor 1.cryptococcus neoformans is the only encapsulated human-pathogenic fungus and a facultative intracellular pathogen that can reside in macrophages without host cell lysis. in the present study, we investigated how phagocytosis of c. neoformans affected the macrophage response to chemoattractants such as fractalkine (fkn) (cx3cl1) and colony-stimulating factor 1 (csf-1). phagocytosis of immunoglobulin g (igg)-opsonized c. neoformans and igg- or c3bi-opsonized sheep erythrocytes was performed using ...200919620351
mutational meltdown in primary endosymbionts: selection limits muller's ratchet.primary bacterial endosymbionts of insects (p-endosymbionts) are thought to be undergoing the process of muller's ratchet where they accrue slightly deleterious mutations due to genetic drift in small populations with negligible recombination rates. if this process were to go unchecked over time, theory predicts mutational meltdown and eventual extinction. although genome degradation is common among p-endosymbionts, we do not observe widespread p-endosymbiont extinction, suggesting that muller's ...200919305500
inhibition of the human neutrophil nadph oxidase by coxiella burnetii.coxiella burnetii is an obligate intracellular gram-negative pathogen. a notable feature of c. burnetii is its ability to replicate within acidic phagolysosomes; however, the mechanisms utilized in evading host defenses are not well defined. here, we investigated human neutrophil phagocytosis of c. burnetii (nine mile, phase ii; nmii) and the effect of phagocytosed organisms on neutrophil reactive oxygen species (ros) production. we found that opsonization with immune serum substantially enhance ...200919379824
simultaneous detection of cdc category "a" dna and rna bioterrorism agents by use of multiplex pcr & rt-pcr enzyme hybridization assays.assays to simultaneously detect multiple potential agents of bioterrorism are limited. two multiplex pcr and rt-pcr enzyme hybridization assays (mpcr-eha, mrt-pcr-eha) were developed to simultaneously detect many of the cdc category "a" bioterrorism agents. the "bio t" dna assay was developed to detect: variola major (vm), bacillus anthracis (ba), yersinia pestis (yp), francisella tularensis (ft) and varicella zoster virus (vzv). the "bio t" rna assay (mrt-pcr-eha) was developed to detect: ebola ...200920224751
development of real-time multiplex nucleic acid sequence-based amplification for detection of mycoplasma pneumoniae, chlamydophila pneumoniae, and legionella spp. in respiratory specimens.real-time multiplex isothermal nucleic acid sequence-based amplification (nasba) was developed to detect mycoplasma pneumoniae, chlamydophila pneumoniae, and legionella spp. in respiratory specimens using the nuclisens basic kit (biomérieux, boxtel, the netherlands). oligonucleotide primers were derived from the m. pneumoniae, c. pneumoniae, and legionella pneumophila 16s rrna. for real-time detection, molecular beacons were used. specificity was established on a panel of bacterial strains. the ...200818032625
development of real-time multiplex nucleic acid sequence-based amplification for detection of mycoplasma pneumoniae, chlamydophila pneumoniae, and legionella spp. in respiratory specimens.real-time multiplex isothermal nucleic acid sequence-based amplification (nasba) was developed to detect mycoplasma pneumoniae, chlamydophila pneumoniae, and legionella spp. in respiratory specimens using the nuclisens basic kit (biomérieux, boxtel, the netherlands). oligonucleotide primers were derived from the m. pneumoniae, c. pneumoniae, and legionella pneumophila 16s rrna. for real-time detection, molecular beacons were used. specificity was established on a panel of bacterial strains. the ...200818032625
pneumonia research to reduce childhood mortality in the developing world.pneumonia is an illness, usually caused by infection, in which the lungs become inflamed and congested, reducing oxygen exchange and leading to cough and breathlessness. it affects individuals of all ages but occurs most frequently in children and the elderly. among children, pneumonia is the most common cause of death worldwide. historically, in developed countries, deaths from pneumonia have been reduced by improvements in living conditions, air quality, and nutrition. in the developing world ...200818382741
significant role for ladc in initiation of legionella pneumophila infection.previously, we identified ladc in a cohort of genes that were present in legionella pneumophila but absent in other legionella species. here we constructed a ladc mutant of l. pneumophila and assessed its ability to replicate in mammalian cell lines and acanthamoeba castellanii. the ladc mutant was recovered in significantly lower numbers than wild-type l. pneumophila at early time points, which was reversed upon transcomplementation with ladc but not ladc(n430a/r434a), encoding a putative catal ...200818426879
detection of 11 common viral and bacterial pathogens causing community-acquired pneumonia or sepsis in asymptomatic patients by using a multiplex reverse transcription-pcr assay with manual (enzyme hybridization) or automated (electronic microarray) detection.community-acquired pneumonia (cap) and sepsis are important causes of morbidity and mortality. we describe the development of two molecular assays for the detection of 11 common viral and bacterial agents of cap and sepsis: influenza virus a, influenza virus b, respiratory syncytial virus a (rsv a), rsv b, mycoplasma pneumoniae, chlamydophila pneumoniae, legionella pneumophila, legionella micdadei, bordetella pertussis, staphylococcus aureus, and streptococcus pneumoniae. further, we report the ...200818650351
legionella eukaryotic-like type iv substrates interfere with organelle trafficking.legionella pneumophila, the causative agent of legionnaires' disease, evades phago-lysosome fusion in mammalian and protozoan hosts to create a suitable niche for intracellular replication. to modulate vesicle trafficking pathways, l. pneumophila translocates effector proteins into eukaryotic cells through a type ivb macro-molecular transport system called the icm-dot system. in this study, we employed a fluorescence-based translocation assay to show that 33 previously identified legionella euka ...200818670632
the guinea pig as a model of infectious diseases.the words 'guinea pig' are synonymous with scientific experimentation, but much less is known about this species than many other laboratory animals. this animal model has been used for approximately 200 y and was the first to be used in the study of infectious diseases such as tuberculosis and diphtheria. today the guinea pig is used as a model for a number of infectious bacterial diseases, including pulmonary, sexually transmitted, ocular and aural, gastrointestinal, and other infections that t ...200818724774
use of flow cytometry to monitor legionella viability.legionella viability was monitored during heat shock treatment at 70 degrees c by a flow cytometric assay (fca). after 30 min of treatment, for 6 of the 12 strains tested, the fca still detected 10 to 25% of cells that were viable but nonculturable (vbnc). these vbnc cells were able to produce atp and to be resuscitated after culture on amoebae.200818849449
the incidence and clinical implication of sputum with positive acid-fast bacilli smear but negative in mycobacterial culture in a tertiary referral hospital in south korea.although it is not rare to find sputum that is positive acid-fast bacilli (afb) smear but subsequent culture fails to isolate mycobacteria in clinical practice, the incidence and clinical implication of those sputa from new patients has not been clearly elucidated. the aim of this study was to determine the incidence and clinical implication of sputum with positive afb smear but negative in mycobacterial culture. all sputa that were positive afb smear requested during diagnostic work up for new ...200818955779
rickettsia conorii transcriptional response within inoculation eschar.rickettsia conorii, the causative agent of the mediterranean spotted fever, is transmitted to humans by the bite of infected ticks rhipicephalus sanguineus. the skin thus constitutes an important barrier for the entry and propagation of r. conorii. given this, analysis of the survival strategies used by the bacterium within infected skin is critical for our understanding of rickettsiosis.200818997861
high prevalence of antibodies to legionella spp. in danish blood donors. a study in areas with high and average incidence of legionnaires' disease.the incidence of legionnaires' disease has an uneven geographical distribution in denmark, ranging from 3 to 70 notified cases per million inhabitants per year in different towns. we investigated the prevalence of antibodies to legionella in the one town with a consistently high incidence (randers, aarhus county) and compared it with that of an area of average incidence (vejle, vejle county). blood samples were collected from healthy blood donors in randers (n=308) and in vejle (n=400), and anal ...200817475092
high prevalence of antibodies to legionella spp. in danish blood donors. a study in areas with high and average incidence of legionnaires' disease.the incidence of legionnaires' disease has an uneven geographical distribution in denmark, ranging from 3 to 70 notified cases per million inhabitants per year in different towns. we investigated the prevalence of antibodies to legionella in the one town with a consistently high incidence (randers, aarhus county) and compared it with that of an area of average incidence (vejle, vejle county). blood samples were collected from healthy blood donors in randers (n=308) and in vejle (n=400), and anal ...200817475092
community-acquired lung abscess caused by legionella micdadei in a myeloma patient receiving thalidomide treatment.legionella infection causes 2 to 14% of community-acquired pneumonia (cap). legionella micdadei constitutes <1% of these infections. we describe a case of cavitary l. micdadei cap in a myeloma patient receiving thalidomide treatment. the importance of considering pneumonia and problems in diagnosing pneumonia caused by l. micdadei in this patient population are reviewed.200717609324
increased rainfall is associated with increased risk for legionellosis.legionnaires' disease (ld) is caused by legionella species, most of which live in water. the mid-atlantic region experienced a sharp rise in ld in 2003 coinciding with a period of record-breaking rainfall. to investigate a possible relationship, we analysed the association between monthly legionellosis incidence and monthly rainfall totals from january 1990 to december 2003 in five mid-atlantic states. using negative binomial model a 1-cm increase in rainfall was associated with a 2.6% (rr 1.026 ...200717121693
increased rainfall is associated with increased risk for legionellosis.legionnaires' disease (ld) is caused by legionella species, most of which live in water. the mid-atlantic region experienced a sharp rise in ld in 2003 coinciding with a period of record-breaking rainfall. to investigate a possible relationship, we analysed the association between monthly legionellosis incidence and monthly rainfall totals from january 1990 to december 2003 in five mid-atlantic states. using negative binomial model a 1-cm increase in rainfall was associated with a 2.6% (rr 1.026 ...200717121693
molecular typing of a legionella pneumophila outbreak in ontario, canada.an outbreak of legionnaires' disease at a long-term care facility in ontario, canada from september to october 2005 resulted in the death of 23 residents and the illness of 112 other people. in response, molecular methods were developed to detect legionella pneumophila in clinical lung samples and to subtype isolates from clinical and environmental samples. the targeted genetic loci included legionella-specific virulence determinants (mip, icmo, sida and lida) and core bacterial determinants (ft ...200717314363
outbreak of legionnaires' disease on a cruise ship linked to spa-bath filter stones contaminated with legionella pneumophila serogroup 5.in january 2003, two cases of legionnaires' disease associated with a ship's cruise were registered in the database of national epidemiological surveillance of infectious diseases. a 70-year-old male heavy smoker with mild emphysema contracted the disease during a cruise. legionella pneumophila serogroup (sg) 5 was isolated from the patient's sputum and the ship's indoor spa. the isolate from the spa matched the patient's isolate by genotyping performed by pulsed-field gel electrophoresis (pfge) ...200616490144
outbreak of legionnaires' disease on a cruise ship linked to spa-bath filter stones contaminated with legionella pneumophila serogroup 5.in january 2003, two cases of legionnaires' disease associated with a ship's cruise were registered in the database of national epidemiological surveillance of infectious diseases. a 70-year-old male heavy smoker with mild emphysema contracted the disease during a cruise. legionella pneumophila serogroup (sg) 5 was isolated from the patient's sputum and the ship's indoor spa. the isolate from the spa matched the patient's isolate by genotyping performed by pulsed-field gel electrophoresis (pfge) ...200616490144
identification of legionella pneumophila-specific genes by genomic subtractive hybridization with legionella micdadei and identification of lpne, a gene required for efficient host cell entry.legionella pneumophila is a ubiquitous environmental organism and a facultative intracellular pathogen of humans. to identify genes that may contribute to the virulence of l. pneumophila, we performed genomic subtractive hybridization between l. pneumophila serogroup 1 strain 02/41 and l. micdadei strain 02/42. a total of 144 l. pneumophila-specific clones were sequenced, revealing 151 genes that were absent in l. micdadei strain 02/42. low-stringency southern hybridization was used to determine ...200616495539
pontiac fever: an operational definition for epidemiological studies.pontiac fever is usually described in epidemic settings. detection of pontiac fever is a marker of an environmental contamination by legionella and should thereby call for prevention measures in order to prevent outbreak of legionnaire's disease. the objective of this study is to propose an operational definition of pontiac fever that is amenable to epidemiological surveillance and investigation in a non epidemic setting.200616646972
compensatory functions of two alkyl hydroperoxide reductases in the oxidative defense system of legionella pneumophila.legionella pneumophila expresses two catalase-peroxidase enzymes that exhibit strong peroxidatic but weak catalatic activities, suggesting that other enzymes participate in decomposition of hydrogen peroxide (h2o2). comparative genomics revealed that l. pneumophila and its close relative coxiella burnetii each contain two peroxide-scavenging alkyl hydroperoxide reductase (ahpc) systems: ahpc1, which is similar to the helicobacter pylori ahpc system, and ahpc2 ahpd (ahpc2d), which is similar to t ...200616923890
detection of coccidioides species in clinical specimens by real-time pcr.coccidioides spp. are dimorphic fungal pathogens endemic to the semiarid regions of north, central, and south america. currently, direct smear and culture are the most common means of identifying coccidioides spp. while these methods offer relatively sensitive and specific means of detecting coccidioides spp., growth in culture may take up to 3 weeks, potentially delaying the diagnosis and initiation of appropriate antifungal therapy. in addition, growth of the organism represents a significant ...200617108077
detection of coccidioides species in clinical specimens by real-time pcr.coccidioides spp. are dimorphic fungal pathogens endemic to the semiarid regions of north, central, and south america. currently, direct smear and culture are the most common means of identifying coccidioides spp. while these methods offer relatively sensitive and specific means of detecting coccidioides spp., growth in culture may take up to 3 weeks, potentially delaying the diagnosis and initiation of appropriate antifungal therapy. in addition, growth of the organism represents a significant ...200617108077
60 years of progress--cdc and infectious diseases. 200616845775
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