Objective To establish Surface-enhanced Raman Spectroscopy（SERS） can be used as a rapid and reliable method to distinguish virulent strain and mild strain of L. pneumophila. Methods We isolated and characterized of ...Objective To establish Surface-enhanced Raman Spectroscopy（SERS） can be used as a rapid and reliable method to distinguish virulent strain and mild strain of L. pneumophila. Methods We isolated and characterized of bacterial strains from ATCC and water samples strains, while we analyzed data from SERS technology using gold nanoparticles as a base and cell infections were employed to rapidly detect L. pneumophila strains. Origin 8.0 was used to collect Raman spectra, smooth and homogenize data, and to contrast spectra. Principal component analysis（PCA） was conducted to discriminate differences between groups using the multivariate analysis package Py Chem 3.0.5. Results Our results indicated that the peaks of high virulence strains reached ≥4000. This criterion was verified by subsequent cell experiments. In addition, we also conducted SERS rapid identification on the virulence of several collected clinical strains and obtained accurate results. Conclusion The present study indicates that the established SERS protocol can be used as a rapid and reliable method to distinguish virulent and mildly virulent strains of L. pneumophila, which can be further used in clinical samples.展开更多
Legionella pneumophila is a Gram-negative bacterium ubiquitously present in freshwater environments and causes a serious type of pneumonia called Legionnaires’disease.During infections,L.pneumophila releases over 300...Legionella pneumophila is a Gram-negative bacterium ubiquitously present in freshwater environments and causes a serious type of pneumonia called Legionnaires’disease.During infections,L.pneumophila releases over 300 effector proteins into host cells through an Icm/Dot type IV secretion system to manipulate the host defense system for survival within the host.Notably,certain effector proteins mediate posttranslational modifications(PTMs),serving as useful approaches exploited by L.pneumophila to modify host proteins.Some effectors catalyze the addition of host protein PTMs,while others mediate the removal of PTMs from host proteins.In this review,we summarize L.pneumophila effector-mediated PTMs of host proteins,including phosphorylation,ubiquitination,glycosylation,AMPylation,phosphocholination,methylation,and ADP-ribosylation,as well as dephosphorylation,deubiquitination,deAMPylation,deADP-ribosylation,dephosphocholination,and delipidation.We describe their molecular mechanisms and biological functions in the regulation of bacterial growth and Legionella-containing vacuole biosynthesis and in the disruption of host immune and defense machinery.展开更多
To facilitate survival,replication,and dissemination,the intracellular pathogen Legionella pneumophila relies on its unique type IVB secretion system(T4SS)to deliver over 330 effectors to hijack host cell pathways in a...To facilitate survival,replication,and dissemination,the intracellular pathogen Legionella pneumophila relies on its unique type IVB secretion system(T4SS)to deliver over 330 effectors to hijack host cell pathways in a spatiotemporal manner.The effectors and their host targets are largely unexplored due to their low sequence identity to the known proteins and functional redundancy.The T4SS effector SidN(Lpg1083)is secreted into host cells during the late infection period.However,to the best of our knowledge,the molecular characterization of SidN has not been studied.Herein,we identified SidN as a nuclear envelope-localized effector.Its structure adopts a novel fold,and the N-terminal domain is crucial for its specific subcellular localization.Furthermore,we found that SidN is transported by eukaryotic karyopherin Importin-13 into the nucleus,where it attaches to the N-terminal region of Lamin-B2 to interfere with the integrity of the nuclear envelope,causing nuclear membrane disruption and eventually cell death.Our work provides new insights into the structure and function of an L.pneumophila effector protein,and suggests a potential strategy utilized by the pathogen to promote host cell death and then escape from the host for secondary infection.展开更多
Objective:To investigate the prevalence,isolation,identification,characterization,antibiotic profile and pathogenicity of Legionellae isolated from various set of waters.Methods:A total of 400 water samples were colle...Objective:To investigate the prevalence,isolation,identification,characterization,antibiotic profile and pathogenicity of Legionellae isolated from various set of waters.Methods:A total of 400 water samples were collected from different water sources.Water samples were pretreated using acid treatment followed by concentration and culture on buffered charcoal yeast extract agar.Parameters like ability of Legionella isolates to grow in various p H range,effect of different concentrations of chlorine and effect of different temperature optima were set up.Biochemical tests were performed to separate Legionellae into species.Antibiotic sensitivity tests and test for pathogenicity were also conducted on isolated strains.Results:The rates of isolation of Legionella pneumophila(L.pneumophila) in different water sources were found to be 20%(lakes),10%(ponds),8%(water-tanks) and 1%(rivers).Most of the isolates could grow in variable p H 6–8 and it could also survive the normal level of chlorination and even at temperature of 42 C.Isolated species of Legionellae resulted in identification of 5 different species,L.pneumophila being the dominant one.Strains of L.pneumophila were resistant to many antibiotics.Inoculation of Legionellae into intracerebral route of suckling mice revealed that L.pneumophila was the most virulent.Conclusions:Serious and fatal L.pneumophila infections may be transmitted through water.Legionella can survive under various conditions in various water sources.L.pneumophila is the important pathogen causing human disease.Great challenge prevails to health care professionals because these Legionellae acquired antibiotic resistance to many routinely prescribed antibiotics.展开更多
We present the case of a 42-year-old man affected by psoriasis with Staphylococcus Haemolyticus superin-fection of Legionella pneumonia during infliximab therapy. The introduction of compounds that block TNF-α has yi...We present the case of a 42-year-old man affected by psoriasis with Staphylococcus Haemolyticus superin-fection of Legionella pneumonia during infliximab therapy. The introduction of compounds that block TNF-α has yielded great benefits for patients affected by selected autoimmune diseases that fail to respond to classic anti-inflammatory agents, but, on the other hand, has led to an increased susceptibility to infec-tions, in particular of those caused by intracellular pathogens, such as L. Pneumophila. Emerging evi-dence suggests that legionellosis can be complicated by superinfection with other agents, including sap-rophytic microorganisms, among which coagulase- negative staphylococci. To our knowledge, this is the first report of systemic legionellosis with superinfec-tion by S. Haemolyticus, an emerging nosocomial multi-resistant pathogen that commonly causes sep-ticemia, osteomyelitis or endocarditis, but has not so far been associated with necrotizing pneumonia. De-spite the optimal antimicrobial therapy for Staphylo-coccus spp. pneumonia is still controversial, evidence suggests that in patients with confirmed positivity for methicillin resistant strains, particularly if sensitivity to vancomycin is suboptimal, linezolid should be the first choice therapy, being superior to vancomycin and teicoplanin.展开更多
BACKGROUND Legionella pneumophila(L.pneumophila)is a gram-negative intracellular bacillus composed of sixteen different serogroups.It is mostly known to cause pneumonia in individuals with known risk factors as immuno...BACKGROUND Legionella pneumophila(L.pneumophila)is a gram-negative intracellular bacillus composed of sixteen different serogroups.It is mostly known to cause pneumonia in individuals with known risk factors as immunocompromised status,tobacco use,chronic organ failure or age older than 50 years.Although parapneumonic pleural effusion is frequent in legionellosis,pleural empyema is very uncommon.In this study,we report a case of fatal pleural empyema caused by L.pneumophila serogroup 1 in an 81-year-old man with multiple risk factors.CASE SUMMARY An 81-year-old man presented to the emergency with a 3 wk dyspnea,fever and left chest pain.His previous medical conditions were chronic lymphocytic leukemia,diabetes mellitus,chronic kidney failure,hypertension and hyperlipidemia,without tobacco use.Chest X-ray and comouted tomographyscan confirmed a large left pleural effusion,which puncture showed a citrine exudate with negative standard bacterial cultures.Despite intravenous cefotaxime antibiotherapy,patient’s worsening condition after 10 d led to thoracocentesis and evacuation of 2 liters of pus.The patient progressively developed severe hypoxemia and multiorgan failure occurred.The patient was treated by antibiotherapy with cefepime and amikacin and with adequate symptomatic shock treatment,but died of uncontrolled sepsis.The next day,cultures of the surgical pleural liquid samples yielded L.pneumophila serogroup 1,consistent with the diagnosis of pleural legionellosis.CONCLUSION L.pneumophila should be considered in patients with multiple risk factors and undiagnosed pleural empyema unresponsive to conventional antibiotherapy.展开更多
BACKGROUND Diffuse large B-cell lymphoma(DLBCL)is a common non-Hodgkin's lymphoma.R-CHOP is a protocol for long-term chemotherapy for DLBCL patients.Longterm chemotherapy can lead to low immunity and increase the ...BACKGROUND Diffuse large B-cell lymphoma(DLBCL)is a common non-Hodgkin's lymphoma.R-CHOP is a protocol for long-term chemotherapy for DLBCL patients.Longterm chemotherapy can lead to low immunity and increase the risk of opportunistic pathogen infections in immunocompromised patients.CASE SUMMARY We report a case of coinfection with Pneumocystis jirovecii(P.jirovecii)and Legionella pneumophila(L.pneumophila)in a patient with DLBCL.The patient was a 40-year-old female who was diagnosed with DLBCL and was admitted due to pulmonary infection.P.jirovecii and L.pneumophila were detected in her bronchoalveolar lavage fluid by hexamine silver staining,isothermal amplification and metagenomic sequencing.CONCLUSION To the best of our knowledge,this is the first case of P.jirovecii and L.pneumophila coinfection found in a DLBCL patient.Clinicians should be aware of the risk of complicated infection in patients undergoing long-term chemotherapy.展开更多
Legionella pneumophila infection can cause Legionnaires’disease,a severe form of pneumonia.Extrapulmonary manifestations of Legionella infections include myocarditis,pericarditis,and endocarditis.We present a rare ca...Legionella pneumophila infection can cause Legionnaires’disease,a severe form of pneumonia.Extrapulmonary manifestations of Legionella infections include myocarditis,pericarditis,and endocarditis.We present a rare case of pneumonia caused by Legionella pneumophila with a possible etiologic link to a recently recovered culture-negative infective endocarditis.展开更多
Legionellosis is the generic term used to describe infections caused by different varieties of Legionella spp.,including Legionnaires'disease(LD),a severe and potentially fatal form of pneumonia,and Pontiac fever,...Legionellosis is the generic term used to describe infections caused by different varieties of Legionella spp.,including Legionnaires'disease(LD),a severe and potentially fatal form of pneumonia,and Pontiac fever,a self-limited flu-like illness.Legionellosis is usually acquired through inhalation or aspiration of aerosols containing Legionella spp.These bacteria can cause acute consolidating pneumonia in susceptible patients who are at an advanced age,have underlying debilitating diseases,or are immunodeficient.The main natural reservoir for Legionella is water and this pathogen colonizes many different natural and man-made freshwater environments such as water networks,cooling towers,and water systems in buildings and hospitals.In recent years,various laboratory diagnostic tests for Legionella infections have changed significantly.Although the sequencing method is nowadays considered the fastest and most reliable method for differentiation and detection of different Legionella species,the isolation of these bacteria from clinical specimens is the golden standard for diagnosis of Legionnaires'disease.Today the urinary antigen test as the most rapid and inexpensive method is routinely used for diagnosis of LD caused by Legionella pneumophila serogroup 1.The macrolides and fluoroquinolones are still the mainstays for the treatment of Legionella infections.For the prevention of spreading the contaminated water aerosols and controlling Legionella infections,an effective water treatment procedure is necessary.This review describs and summarizes the latest available information about all aspects of Legionella and Legionnaires'disease.展开更多
In this study the authors compared the sequence types （STs） designed by sequence based typing （SBT） of 4 clinical and 12 environmental strains of Legionella pneumophila serogroup 1 （LP1） which were isolated from...In this study the authors compared the sequence types （STs） designed by sequence based typing （SBT） of 4 clinical and 12 environmental strains of Legionella pneumophila serogroup 1 （LP1） which were isolated from hospital facilities for the mentally disabled. The strains were selected after a retrospective surveillance of 565 clinical records （2002-2009） and investigations of water circuit. It was possible to correlate two clinical strains with the corresponding environment, which were collected from showers that had exposed the patients （ST685, ST16） and two clinical strains present in the same structure （STI）. The other environmental strains were isolated from water in the department with confirmed or suspected clinical cases. All the strains （seven） from the first structure had ST188; two from the second structure had ST34; and the last from the third structure, gave an ST694. The results were compared with the European Working Group for Legionella Infections （EWGLI） database： the ST 1, 16, 34 and 188 were already known in literature, among clinical and nosocomial cases, especially for ST 1, the most distributed worldwide. Two STs were new to the database. ST685 was isolated both from a patient and from the water; ST694, which was found exclusively in the environmental compartment of a control structure （no cases of legionellosis and low number of nosocomial pneumonia）, was unknown in the literature and the authors could only speculate on its possible minor virulence and/or distribution. The implementation of SBT and international comparisons may be useful to gain genotypic knowledge of circulating environmental strains, also verifying their presence in the clinical setting.展开更多
Objective:To investigate the presence of Legionella pneumophila(L.pneumophila)in domestic water in Bitlis province and to determine the in vitro susceptibility of the isolates against several antibiotics.Methods:A tot...Objective:To investigate the presence of Legionella pneumophila(L.pneumophila)in domestic water in Bitlis province and to determine the in vitro susceptibility of the isolates against several antibiotics.Methods:A total of 320 tap water samples were collected from the urban areas and villages of Bitlis province during the period from May to December 2010.All samples were cultured on plates of buffered charcoal yeast extract agar.L.pneumophila strains were tested for antimicrobial susceptibility by the disk diffusion method.Results:L.pneumophila strains were isolated from six(1.9%)domestic water samples.All isolates were typed as L.pneumophila serogroup 1 by latex agglutination test.Four of strains were isolated in July and two of them were detected in August.Antibiotic susceptibility testing was carried out on six L.pneumophila serogroup 1 isolates.Of the six strains,two was resistant to erythromycin and streptomycin,four were resistant to ampicillin and gentamicin,but all were sensitive to chloramphenicol and doxycycline.Conclusions:Our results indicate that L.pneumophila serogroup 1 is the most common type in the domestic water samples and threats public health.This is the first report of L.pneumophila in domestic water samples from Bitlis province.展开更多
Legionellae are found in freshwater environments or wet soil, but the major reservoirs are man-made aquatic environments, particularly warm water systems. Our aim was to study the occurrence of Legionella contaminatio...Legionellae are found in freshwater environments or wet soil, but the major reservoirs are man-made aquatic environments, particularly warm water systems. Our aim was to study the occurrence of Legionella contamination in hot potable water supply systems in apartment and public buildings. Correlations between Legionella spp. positive cases and water source, sampling point and temperature of hot water at the point of consumption were studied. A total of 149 hot water samples were collected in 16 cities and districts of Latvia. Only Legionella pneumophila was isolated. L. pneumophila was found in 63 out of 149 （42%） hot water samples. From all Legionella spp. positive samples, 17% represented L. pneumophila serogroup 1 and 78% L. pneumophila serogroups 2-14 （15）. In 5% of Legionella spp. positive samples, both serogroups 1 and 2-14（15） were isolated. Statistically significant differences were observed in the distribution of L. pneumophila serogroup 1 in samples from various water sources. L. pneumophila was found in 45% of samples from private apartments and in 27% of samples from public buildings. Data analysis confirmed that the temperature of hot water significantly affects the frequency of L. pneumophila positive cases （p 〈 0.05）. Data showed that 85% of consumers received hot water at a temperature below 50°C.展开更多
Legionella is a causative agent of legionellosis or Legionnaires’disease.Infection with Legionella spp.is an important cause of community and hospital-acquired pneumonia.Moreover,infection with Legionella is one of t...Legionella is a causative agent of legionellosis or Legionnaires’disease.Infection with Legionella spp.is an important cause of community and hospital-acquired pneumonia.Moreover,infection with Legionella is one of the most common causes of severe pneumonia in community settings,and Legionella is isolated in 40%of hospital-acquired pneumonia cases.The clinical features of legionellosis or Legionnaires’disease are not unique,which makes the diagnosis challenging.Macrolides andfluoroquinolones are the most widely used drugs in treatment.Early recognition,treatment and effective measures for prevention and control of the disease are important and required.Although there have been a lot of methods for diagnosis of Legionella infection,they were often time-consuming or complex,not suitable for clinical purposes.This review summarizes available information regarding the microbiology,taxonomy,epidemiology,pathogenesis and diagnosis of Legionnaires’disease,with an emphasis on the laboratory diagnosis of infection with Legionella spp.展开更多
Sixty six water samples were collected from inlets, inside and outlets of cooling towers （22 samples each, once a week）. Samples were screened for bacterial colonization with special focus on Legionella. Percentage ...Sixty six water samples were collected from inlets, inside and outlets of cooling towers （22 samples each, once a week）. Samples were screened for bacterial colonization with special focus on Legionella. Percentage occurrence of predominant bacteria present in water samples collected from inlets included： Klebsiella （95.45%）, Enterobacter （90.9%）, Pseudomonas （86.36%）, Escherichia coli （81.81%）, and Legionella （72.72%）. While those predominant in water inside cooling towers were： Pseudomonas （100%）, Staphylococci （81.81%）, Legionella （81.81%） and Bacillus （72.72%）. Incidence of Legionella recovered from inside and outlets of cooling towers sites was similar. Four species of Legionella were identified in water samples collected from inlets, inside and outlets of cooling towers, in the following consecutive frequencies L. pneumophila （72.72%, 81.81% and 81.81%）, L. jordans （18.18%, 36.36% and 27.27%）, L. dumffii （9.09%, 22.72% and 22.72%） and L. oekidegenes （4.54%, 13.63% and 18.18%）. The increased percentage occurrence of Legionella in water collected from inlets and inside cooling towers, as well as those of Pseudomonas and Staphylococci suggest that Legionella is also a hardy organism, being potentially survive as free organism despite water disinfection.展开更多
基金supported by National Key Technologies Research and Development Program of China(2013ZX10004-610)China Ministry of Science and Technology(MOST)Project 973(2012CB955501)WL is a principal investigator of the NSFC Innovative Research Group(Grant No.81321063)
文摘Objective To establish Surface-enhanced Raman Spectroscopy（SERS） can be used as a rapid and reliable method to distinguish virulent strain and mild strain of L. pneumophila. Methods We isolated and characterized of bacterial strains from ATCC and water samples strains, while we analyzed data from SERS technology using gold nanoparticles as a base and cell infections were employed to rapidly detect L. pneumophila strains. Origin 8.0 was used to collect Raman spectra, smooth and homogenize data, and to contrast spectra. Principal component analysis（PCA） was conducted to discriminate differences between groups using the multivariate analysis package Py Chem 3.0.5. Results Our results indicated that the peaks of high virulence strains reached ≥4000. This criterion was verified by subsequent cell experiments. In addition, we also conducted SERS rapid identification on the virulence of several collected clinical strains and obtained accurate results. Conclusion The present study indicates that the established SERS protocol can be used as a rapid and reliable method to distinguish virulent and mildly virulent strains of L. pneumophila, which can be further used in clinical samples.
基金funded by the National Natural Science Foundation of China(32170185,22011530161,31801166,and 91854101)the Natural Science Foundation of Chongqing,China(cstc2021jcyj-msxmX0030 and CSTB2022NSCQ-MSX0463)+2 种基金the Venture Innovation Support Program for Chongqing Overseas Returnees(cx2022066)the Fundamental Research Funds for the Central Universities(2022CDJYGRH-002)the National Training Program of Innovation and Entrepreneurship for Undergraduates(202210611088).
文摘Legionella pneumophila is a Gram-negative bacterium ubiquitously present in freshwater environments and causes a serious type of pneumonia called Legionnaires’disease.During infections,L.pneumophila releases over 300 effector proteins into host cells through an Icm/Dot type IV secretion system to manipulate the host defense system for survival within the host.Notably,certain effector proteins mediate posttranslational modifications(PTMs),serving as useful approaches exploited by L.pneumophila to modify host proteins.Some effectors catalyze the addition of host protein PTMs,while others mediate the removal of PTMs from host proteins.In this review,we summarize L.pneumophila effector-mediated PTMs of host proteins,including phosphorylation,ubiquitination,glycosylation,AMPylation,phosphocholination,methylation,and ADP-ribosylation,as well as dephosphorylation,deubiquitination,deAMPylation,deADP-ribosylation,dephosphocholination,and delipidation.We describe their molecular mechanisms and biological functions in the regulation of bacterial growth and Legionella-containing vacuole biosynthesis and in the disruption of host immune and defense machinery.
基金supported by grants from the National Natural Science Foundation of China(31970103 to H.G.and 32071158 to X.Q.)China Postdoctoral Science Foundation(2021M700178 to X.C.)the Natural Science Foundation of Department of Education of Anhui Province(K120462017 to X.C.).
文摘To facilitate survival,replication,and dissemination,the intracellular pathogen Legionella pneumophila relies on its unique type IVB secretion system(T4SS)to deliver over 330 effectors to hijack host cell pathways in a spatiotemporal manner.The effectors and their host targets are largely unexplored due to their low sequence identity to the known proteins and functional redundancy.The T4SS effector SidN(Lpg1083)is secreted into host cells during the late infection period.However,to the best of our knowledge,the molecular characterization of SidN has not been studied.Herein,we identified SidN as a nuclear envelope-localized effector.Its structure adopts a novel fold,and the N-terminal domain is crucial for its specific subcellular localization.Furthermore,we found that SidN is transported by eukaryotic karyopherin Importin-13 into the nucleus,where it attaches to the N-terminal region of Lamin-B2 to interfere with the integrity of the nuclear envelope,causing nuclear membrane disruption and eventually cell death.Our work provides new insights into the structure and function of an L.pneumophila effector protein,and suggests a potential strategy utilized by the pathogen to promote host cell death and then escape from the host for secondary infection.
基金Supported by Rockefeller Foundation,USA(Grant No.External-R.F-2396725281-2015-16)
文摘Objective:To investigate the prevalence,isolation,identification,characterization,antibiotic profile and pathogenicity of Legionellae isolated from various set of waters.Methods:A total of 400 water samples were collected from different water sources.Water samples were pretreated using acid treatment followed by concentration and culture on buffered charcoal yeast extract agar.Parameters like ability of Legionella isolates to grow in various p H range,effect of different concentrations of chlorine and effect of different temperature optima were set up.Biochemical tests were performed to separate Legionellae into species.Antibiotic sensitivity tests and test for pathogenicity were also conducted on isolated strains.Results:The rates of isolation of Legionella pneumophila(L.pneumophila) in different water sources were found to be 20%(lakes),10%(ponds),8%(water-tanks) and 1%(rivers).Most of the isolates could grow in variable p H 6–8 and it could also survive the normal level of chlorination and even at temperature of 42 C.Isolated species of Legionellae resulted in identification of 5 different species,L.pneumophila being the dominant one.Strains of L.pneumophila were resistant to many antibiotics.Inoculation of Legionellae into intracerebral route of suckling mice revealed that L.pneumophila was the most virulent.Conclusions:Serious and fatal L.pneumophila infections may be transmitted through water.Legionella can survive under various conditions in various water sources.L.pneumophila is the important pathogen causing human disease.Great challenge prevails to health care professionals because these Legionellae acquired antibiotic resistance to many routinely prescribed antibiotics.
文摘We present the case of a 42-year-old man affected by psoriasis with Staphylococcus Haemolyticus superin-fection of Legionella pneumonia during infliximab therapy. The introduction of compounds that block TNF-α has yielded great benefits for patients affected by selected autoimmune diseases that fail to respond to classic anti-inflammatory agents, but, on the other hand, has led to an increased susceptibility to infec-tions, in particular of those caused by intracellular pathogens, such as L. Pneumophila. Emerging evi-dence suggests that legionellosis can be complicated by superinfection with other agents, including sap-rophytic microorganisms, among which coagulase- negative staphylococci. To our knowledge, this is the first report of systemic legionellosis with superinfec-tion by S. Haemolyticus, an emerging nosocomial multi-resistant pathogen that commonly causes sep-ticemia, osteomyelitis or endocarditis, but has not so far been associated with necrotizing pneumonia. De-spite the optimal antimicrobial therapy for Staphylo-coccus spp. pneumonia is still controversial, evidence suggests that in patients with confirmed positivity for methicillin resistant strains, particularly if sensitivity to vancomycin is suboptimal, linezolid should be the first choice therapy, being superior to vancomycin and teicoplanin.
文摘BACKGROUND Legionella pneumophila(L.pneumophila)is a gram-negative intracellular bacillus composed of sixteen different serogroups.It is mostly known to cause pneumonia in individuals with known risk factors as immunocompromised status,tobacco use,chronic organ failure or age older than 50 years.Although parapneumonic pleural effusion is frequent in legionellosis,pleural empyema is very uncommon.In this study,we report a case of fatal pleural empyema caused by L.pneumophila serogroup 1 in an 81-year-old man with multiple risk factors.CASE SUMMARY An 81-year-old man presented to the emergency with a 3 wk dyspnea,fever and left chest pain.His previous medical conditions were chronic lymphocytic leukemia,diabetes mellitus,chronic kidney failure,hypertension and hyperlipidemia,without tobacco use.Chest X-ray and comouted tomographyscan confirmed a large left pleural effusion,which puncture showed a citrine exudate with negative standard bacterial cultures.Despite intravenous cefotaxime antibiotherapy,patient’s worsening condition after 10 d led to thoracocentesis and evacuation of 2 liters of pus.The patient progressively developed severe hypoxemia and multiorgan failure occurred.The patient was treated by antibiotherapy with cefepime and amikacin and with adequate symptomatic shock treatment,but died of uncontrolled sepsis.The next day,cultures of the surgical pleural liquid samples yielded L.pneumophila serogroup 1,consistent with the diagnosis of pleural legionellosis.CONCLUSION L.pneumophila should be considered in patients with multiple risk factors and undiagnosed pleural empyema unresponsive to conventional antibiotherapy.
文摘BACKGROUND Diffuse large B-cell lymphoma(DLBCL)is a common non-Hodgkin's lymphoma.R-CHOP is a protocol for long-term chemotherapy for DLBCL patients.Longterm chemotherapy can lead to low immunity and increase the risk of opportunistic pathogen infections in immunocompromised patients.CASE SUMMARY We report a case of coinfection with Pneumocystis jirovecii(P.jirovecii)and Legionella pneumophila(L.pneumophila)in a patient with DLBCL.The patient was a 40-year-old female who was diagnosed with DLBCL and was admitted due to pulmonary infection.P.jirovecii and L.pneumophila were detected in her bronchoalveolar lavage fluid by hexamine silver staining,isothermal amplification and metagenomic sequencing.CONCLUSION To the best of our knowledge,this is the first case of P.jirovecii and L.pneumophila coinfection found in a DLBCL patient.Clinicians should be aware of the risk of complicated infection in patients undergoing long-term chemotherapy.
文摘Legionella pneumophila infection can cause Legionnaires’disease,a severe form of pneumonia.Extrapulmonary manifestations of Legionella infections include myocarditis,pericarditis,and endocarditis.We present a rare case of pneumonia caused by Legionella pneumophila with a possible etiologic link to a recently recovered culture-negative infective endocarditis.
文摘Legionellosis is the generic term used to describe infections caused by different varieties of Legionella spp.,including Legionnaires'disease(LD),a severe and potentially fatal form of pneumonia,and Pontiac fever,a self-limited flu-like illness.Legionellosis is usually acquired through inhalation or aspiration of aerosols containing Legionella spp.These bacteria can cause acute consolidating pneumonia in susceptible patients who are at an advanced age,have underlying debilitating diseases,or are immunodeficient.The main natural reservoir for Legionella is water and this pathogen colonizes many different natural and man-made freshwater environments such as water networks,cooling towers,and water systems in buildings and hospitals.In recent years,various laboratory diagnostic tests for Legionella infections have changed significantly.Although the sequencing method is nowadays considered the fastest and most reliable method for differentiation and detection of different Legionella species,the isolation of these bacteria from clinical specimens is the golden standard for diagnosis of Legionnaires'disease.Today the urinary antigen test as the most rapid and inexpensive method is routinely used for diagnosis of LD caused by Legionella pneumophila serogroup 1.The macrolides and fluoroquinolones are still the mainstays for the treatment of Legionella infections.For the prevention of spreading the contaminated water aerosols and controlling Legionella infections,an effective water treatment procedure is necessary.This review describs and summarizes the latest available information about all aspects of Legionella and Legionnaires'disease.
文摘In this study the authors compared the sequence types （STs） designed by sequence based typing （SBT） of 4 clinical and 12 environmental strains of Legionella pneumophila serogroup 1 （LP1） which were isolated from hospital facilities for the mentally disabled. The strains were selected after a retrospective surveillance of 565 clinical records （2002-2009） and investigations of water circuit. It was possible to correlate two clinical strains with the corresponding environment, which were collected from showers that had exposed the patients （ST685, ST16） and two clinical strains present in the same structure （STI）. The other environmental strains were isolated from water in the department with confirmed or suspected clinical cases. All the strains （seven） from the first structure had ST188; two from the second structure had ST34; and the last from the third structure, gave an ST694. The results were compared with the European Working Group for Legionella Infections （EWGLI） database： the ST 1, 16, 34 and 188 were already known in literature, among clinical and nosocomial cases, especially for ST 1, the most distributed worldwide. Two STs were new to the database. ST685 was isolated both from a patient and from the water; ST694, which was found exclusively in the environmental compartment of a control structure （no cases of legionellosis and low number of nosocomial pneumonia）, was unknown in the literature and the authors could only speculate on its possible minor virulence and/or distribution. The implementation of SBT and international comparisons may be useful to gain genotypic knowledge of circulating environmental strains, also verifying their presence in the clinical setting.
文摘Objective:To investigate the presence of Legionella pneumophila(L.pneumophila)in domestic water in Bitlis province and to determine the in vitro susceptibility of the isolates against several antibiotics.Methods:A total of 320 tap water samples were collected from the urban areas and villages of Bitlis province during the period from May to December 2010.All samples were cultured on plates of buffered charcoal yeast extract agar.L.pneumophila strains were tested for antimicrobial susceptibility by the disk diffusion method.Results:L.pneumophila strains were isolated from six(1.9%)domestic water samples.All isolates were typed as L.pneumophila serogroup 1 by latex agglutination test.Four of strains were isolated in July and two of them were detected in August.Antibiotic susceptibility testing was carried out on six L.pneumophila serogroup 1 isolates.Of the six strains,two was resistant to erythromycin and streptomycin,four were resistant to ampicillin and gentamicin,but all were sensitive to chloramphenicol and doxycycline.Conclusions:Our results indicate that L.pneumophila serogroup 1 is the most common type in the domestic water samples and threats public health.This is the first report of L.pneumophila in domestic water samples from Bitlis province.
文摘Legionellae are found in freshwater environments or wet soil, but the major reservoirs are man-made aquatic environments, particularly warm water systems. Our aim was to study the occurrence of Legionella contamination in hot potable water supply systems in apartment and public buildings. Correlations between Legionella spp. positive cases and water source, sampling point and temperature of hot water at the point of consumption were studied. A total of 149 hot water samples were collected in 16 cities and districts of Latvia. Only Legionella pneumophila was isolated. L. pneumophila was found in 63 out of 149 （42%） hot water samples. From all Legionella spp. positive samples, 17% represented L. pneumophila serogroup 1 and 78% L. pneumophila serogroups 2-14 （15）. In 5% of Legionella spp. positive samples, both serogroups 1 and 2-14（15） were isolated. Statistically significant differences were observed in the distribution of L. pneumophila serogroup 1 in samples from various water sources. L. pneumophila was found in 45% of samples from private apartments and in 27% of samples from public buildings. Data analysis confirmed that the temperature of hot water significantly affects the frequency of L. pneumophila positive cases （p 〈 0.05）. Data showed that 85% of consumers received hot water at a temperature below 50°C.
基金supported by the National Standardization Committee(No.20081021-T-361)the Ministry of Science and Technology of China(No.2008ZX10004-006).
文摘Legionella is a causative agent of legionellosis or Legionnaires’disease.Infection with Legionella spp.is an important cause of community and hospital-acquired pneumonia.Moreover,infection with Legionella is one of the most common causes of severe pneumonia in community settings,and Legionella is isolated in 40%of hospital-acquired pneumonia cases.The clinical features of legionellosis or Legionnaires’disease are not unique,which makes the diagnosis challenging.Macrolides andfluoroquinolones are the most widely used drugs in treatment.Early recognition,treatment and effective measures for prevention and control of the disease are important and required.Although there have been a lot of methods for diagnosis of Legionella infection,they were often time-consuming or complex,not suitable for clinical purposes.This review summarizes available information regarding the microbiology,taxonomy,epidemiology,pathogenesis and diagnosis of Legionnaires’disease,with an emphasis on the laboratory diagnosis of infection with Legionella spp.
文摘Sixty six water samples were collected from inlets, inside and outlets of cooling towers （22 samples each, once a week）. Samples were screened for bacterial colonization with special focus on Legionella. Percentage occurrence of predominant bacteria present in water samples collected from inlets included： Klebsiella （95.45%）, Enterobacter （90.9%）, Pseudomonas （86.36%）, Escherichia coli （81.81%）, and Legionella （72.72%）. While those predominant in water inside cooling towers were： Pseudomonas （100%）, Staphylococci （81.81%）, Legionella （81.81%） and Bacillus （72.72%）. Incidence of Legionella recovered from inside and outlets of cooling towers sites was similar. Four species of Legionella were identified in water samples collected from inlets, inside and outlets of cooling towers, in the following consecutive frequencies L. pneumophila （72.72%, 81.81% and 81.81%）, L. jordans （18.18%, 36.36% and 27.27%）, L. dumffii （9.09%, 22.72% and 22.72%） and L. oekidegenes （4.54%, 13.63% and 18.18%）. The increased percentage occurrence of Legionella in water collected from inlets and inside cooling towers, as well as those of Pseudomonas and Staphylococci suggest that Legionella is also a hardy organism, being potentially survive as free organism despite water disinfection.
