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1.
Lett Appl Microbiol ; 72(6): 750-756, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33651401

RESUMO

Legionella species are the causative agent of Legionnaires' disease, a potentially fatal bacterial pneumonia. New regulations and standards have prioritized the development of water safety plans to minimize the growth and spread of Legionella species in buildings. To determine the presence and type of Legionella in a water system, microbiological culturing is the gold standard method. However, recently new methodologies have been developed that claim to be sensitive and specific for Legionella at the genus or L. pneumophila at the species level. Published and anecdotal reports suggest that one of these newer culture-based, enzyme-substrate methods, the IDEXX Legiolert test, may exhibit false positivity with other microbes common to water sources. We experimentally evaluated the IDEXX Legiolert method using these other waterborne bacteria including Elizabethkingia meningoseptica, Pseudomonas aeruginosa, Proteus mirabilis and Serratia marcescens at real-world environmental concentrations. We saw false-positive results for the Legiolert test with several of these organisms, at sample concentrations as low as 60 CFU per ml. False-positive Legionella results can trigger costly remediation and water-use restrictions, that may be implemented while waiting for additional, confirmatory microbiological testing that could, in this case, yield no L. pneumophila.


Assuntos
Monitoramento Ambiental/métodos , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/prevenção & controle , Reações Cruzadas , Reações Falso-Positivas , Humanos , Legionella pneumophila/classificação , Doença dos Legionários/microbiologia , Água , Microbiologia da Água , Abastecimento de Água
2.
Appl Environ Microbiol ; 87(10)2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33674435

RESUMO

In large-building water systems, Legionella pneumophila is exposed to common environmental stressors such as copper. The aim of this study was to evaluate the susceptibility to copper of L. pneumophila isolates recovered from various sites: two clinical and seven environmental isolates from hot water system biofilm and water and from cooling tower water. After a 1-week acclimation in simulated drinking water, strains were exposed to various copper concentrations (0.8 to 5 mg/liter) for over 672 h. Complete loss of culturability was observed for three isolates following copper exposure to 5 mg/liter for 672 h. Two sequence type 1427 (ST1427)-like isolates were highly sensitive to copper, while the other two, isolated from biofilm samples, maintained higher culturability. The expression of the copper resistance gene copA evaluated by reverse transcription-quantitative PCR (RT-qPCR) was significantly higher for the biofilm isolates. All four ST1427-like isolates were recovered from the same water system during an outbreak. Whole-genome sequencing results confirmed that the four isolates are very close phylogenetically, differing by only 29 single nucleotide polymorphisms, suggesting in situ adaptation to microenvironmental conditions, possibly due to epigenetic regulation. These results indicate that the immediate environment within a building water distribution system influences the tolerance of L. pneumophila to copper. Increased contact of L. pneumophila biofilm strains with copper piping or copper alloys in the heat exchanger might lead to local adaptation. The phenotypic differences observed between water and biofilm isolates from the hot water system of a health care facility warrants further investigation to assess the relevance of evaluating disinfection performances based on water sampling alone.IMPORTANCE Legionella pneumophila is a pathogen indigenous to natural and large building water systems in the bulk and the biofilm phases. The immediate environment within a system can impact the tolerance of L. pneumophila to environmental stressors, including copper. In health care facilities, copper levels in water can vary, depending on water quality, plumbing materials, and age. This study evaluated the impact of the isolation site (water versus biofilm, hot water system versus cooling tower) within building water systems. Closely related strains isolated from a health care facility hot water system exhibited variable tolerance to copper stress, shown by differential expression of copA, with biofilm isolates displaying highest expression and tolerance. Relying on the detection of L. pneumophila in water samples following exposure to environmental stressors such as copper may underestimate the prevalence of L. pneumophila, leading to inappropriate risk management strategies and increasing the risk of exposure for vulnerable patients.


Assuntos
Cobre/toxicidade , Água Potável/microbiologia , Hospitais , Legionella pneumophila , Abastecimento de Água , Adaptação Fisiológica , Biofilmes/efeitos dos fármacos , Tolerância a Medicamentos/genética , Genoma Bacteriano , Legionella pneumophila/efeitos dos fármacos , Legionella pneumophila/genética , Legionella pneumophila/isolamento & purificação , Legionella pneumophila/fisiologia , Filogenia
3.
Biosensors (Basel) ; 11(2)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513950

RESUMO

The detection of water contamination with Legionella pneumophila is of critical importance to manufacturers of water processing equipment and public health entities dealing with water networks and distribution systems. Detection methods based on polymerase chain reaction or biosensor technologies require preconcentration steps to achieve attractive sensitivity levels. Preconcentration must also be included in protocols of automated collection of water samples by systems designed for quasi-continuous monitoring of remotely located water reservoirs for the presence of L. pneumophila. We designed and characterized a water sampling module for filtration and backwashing intended for analysis of low-to-medium contaminated water, typically with L. pneumophila bacteria not exceeding 50 colony-forming units per milliliter. The concentration factors of 10× and 21× were achieved with 0.22 and 0.45 µm filters, respectively, for samples of bacteria prepared in clean saline solutions. However, a 5× concentration factor was achieved with 0.45 µm filters for a heavily contaminated or turbid water typical of some industrial water samples.


Assuntos
Monitoramento Ambiental/métodos , Legionella pneumophila/isolamento & purificação , Microbiologia da Água , Filtração , Água , Poluição da Água/estatística & dados numéricos
4.
PLoS One ; 15(8): e0238479, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866217

RESUMO

The performances of the ImmuView Streptococcus pneumoniae (Sp) and Legionella pneumophila (Lp) urinary antigen test were compared to that of the BinaxNOW Sp and Lp assays, using frozen urine from 166 patients with Legionnaires' disease (LD) and 59 patients with pneumococcal pneumonia. Thirty Sp-positive or contrived cerebrospinal fluids (CSF) were also tested. Test specimens were collected and tested at different sites, with each site testing unique specimens by technologists blinded to expected results. No significant differences in test concordances were detected for the ImmuView and BinaxNOW assays for the Sp or Lp targets for urine from patients with pneumococcal pneumonia or LD when performance from both sites were combined. At one of two test sites the ImmuView Lp assay was more sensitive than the BinaxNOW assay, with no correlation between test performance and Lp serogroup 1 monoclonal type. Urines from six of seven patients with LD caused by Legionella spp. bacteria other than Lp serogroup 1 were negative in both assays. Both tests had equivalent performance for Sp-positive CSF. The clinical sensitivities for pneumococcal pneumonia were 88.1 and 94.4% for the ImmuView and Binax assays, and 87.6 and 84.2% for the Lp assays, respectively. Test specificities for pneumococcal pneumonia were 96.2 and 97.0% for the ImmuView and Binax assays, and 99.6 and 99.1% for the Lp assays. Both assays were highly specific for Sp in pediatric urines from children with nasopharyngeal colonization by the bacterium. ImmuView and BinaxNOW assay performance was equivalent in these studies.


Assuntos
Antígenos de Bactérias/metabolismo , Antígenos de Bactérias/urina , Bioensaio/métodos , Líquido Cefalorraquidiano/microbiologia , Legionella pneumophila/isolamento & purificação , Streptococcus pneumoniae/isolamento & purificação , Urina/microbiologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Testes Imunológicos/métodos , Lactente , Doença dos Legionários/metabolismo , Doença dos Legionários/microbiologia , Doença dos Legionários/urina , Masculino , Meningite/metabolismo , Meningite/microbiologia , Meningite/urina , Pneumonia Pneumocócica/metabolismo , Pneumonia Pneumocócica/microbiologia , Pneumonia Pneumocócica/urina , Sensibilidade e Especificidade , Sorogrupo , Adulto Jovem
5.
Artigo em Inglês | MEDLINE | ID: mdl-32796666

RESUMO

The current systematic review investigates the antibiotic susceptibility pattern of Legionella pneumophila isolates from the 1980s to the present day, deriving data from clinical and/or water samples from studies carried out all over the world. Eighty-nine papers meeting the inclusion criteria, i.e., "Legionella pneumophila" and "resistance to antibiotics", were evaluated according to pre-defined validity criteria. Sixty articles referred to clinical isolates, and 18 articles reported water-related L. pneumophila isolates, while 11 articles included both clinical and water isolates. Several methods have been proposed as suitable for the determination of MICs, such as the E-test, broth and agar dilution, and disk diffusion methods, in vivo and in vitro, using various media. The E-test method proposed by the European Society of Clinical Microbiology and Infectious Diseases (EUCAST) seems to be the second most frequently used method overall, but it is the preferred method in the most recent publications (2000-2019) for the interpretation criteria. Erythromycin has been proved to be the preference for resistance testing over the years. However, in the last 19 years, the antibiotics ciprofloxacin (CIP), erythromycin (ERM), levofloxacin (LEV) and azithromycin (AZM) were the ones that saw an increase in their use. A decrease in the sensitivity to antibiotics was identified in approximately half of the reviewed articles.


Assuntos
Antibacterianos/farmacologia , Legionella pneumophila/efeitos dos fármacos , Doença dos Legionários/tratamento farmacológico , Antibacterianos/uso terapêutico , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Eritromicina , Humanos , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/diagnóstico , Testes de Sensibilidade Microbiana
6.
Euro Surveill ; 25(30)2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32734857

RESUMO

We report a case of Legionella pneumonia in a dishwasher of a restaurant in Rome, Italy, just after the end of the lockdown that was in place to control the SARS-CoV-2 epidemic. The case highlights the importance of strict monitoring of water and air systems immediately before reopening business or public sector buildings, and the need to consider Legionella infections among the differential diagnosis of respiratory infections after lockdown due to the ongoing COVID-19 pandemic.


Assuntos
Antígenos de Bactérias/urina , Legionella pneumophila/isolamento & purificação , Legionella/isolamento & purificação , Doença dos Legionários/diagnóstico , Levofloxacino/uso terapêutico , Pneumonia/diagnóstico , Administração Intravenosa , Adulto , Anti-Infecciosos Urinários/uso terapêutico , Tosse/etiologia , Febre/etiologia , Cefaleia/etiologia , Humanos , Doença dos Legionários/tratamento farmacológico , Doença dos Legionários/urina , Masculino , Pneumonia/tratamento farmacológico , Pneumonia/urina , Resultado do Tratamento
7.
Zhonghua Jie He He Hu Xi Za Zhi ; 43(7): 557-563, 2020 Jul 12.
Artigo em Chinês | MEDLINE | ID: mdl-32629554

RESUMO

Objective: To describe the clinical characteristics and treatment of severe community-acquired pneumonia(SCAP) caused by Legionella pneumophila with acute respiratory failure and to analyze the risk factors for mortality. Methods: From October 2011 to October 2019, 34 patients were diagnosed with SCAP caused by Legionella pneumophila with acute respiratory failure.There were 25 males and 9 females, aged from 17 to 82 years, with a median age of 61 (48, 69) years. According to the prognosis, the patients were divided into a survival group and a death group for comparative analysis.The survival group included 24 patients, 17 males and 7 females, with a median age of 65 (55, 70) years. There were 10 cases in the death group, 8 males and 2 females, with a median age of 53 (50, 58) years. Multivariable logistic regression analysis was used for risk factors of ICU mortality. Results: The median time of admission to ICU was 7 (5, 11) days, the median time of stay in RICU was 12 (7, 22) days, and the PaO(2)/FiO(2) was 134 (91, 216) mmHg(1 mmHg=0.133 kPa). Ten patients died during ICU hospitalization, with a mortality of 29%. Sequential organ failure assessment (SOFA) of death group was 9 (7, 12), which was significantly higher than that of the survival group [4 (3, 8)], P=0.018. The time from onset of pneumonia symptoms to initiation of targeted treatment of the death group was 10 (7, 14) d, which was significantly longer than that of the survival group of [4 (3, 7) d], P=0.019. Multivariable logistic regression analysis showed that SOFA score (OR=1.461, 95%CI 1.041-2.051, P=0.028) and the time from onset of pneumonia symptoms to initiation of targeted treatment (OR=1.293, 95%CI 1.029-1.625, P=0.027) were independent risk factors for hospital mortality. Conclusions: The ICU mortality of severe legionella pneumonia was high. Critical organ dysfunctions and delayed initial targeted treatment were related with the increase of ICU mortality.


Assuntos
Infecções Comunitárias Adquiridas/diagnóstico , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/diagnóstico , Pneumonia Bacteriana/diagnóstico , Insuficiência Respiratória , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções Comunitárias Adquiridas/microbiologia , Infecções Comunitárias Adquiridas/mortalidade , Infecções Comunitárias Adquiridas/terapia , Feminino , Humanos , Unidades de Terapia Intensiva , Doença dos Legionários/mortalidade , Doença dos Legionários/terapia , Masculino , Pessoa de Meia-Idade , Pneumonia Bacteriana/mortalidade , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
8.
Int J Infect Dis ; 97: 374-379, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32534142

RESUMO

OBJECTIVES: To report atypical pathogens from clinical trial data comparing delafloxacin to moxifloxacin in the treatment of adults with community-acquired bacterial pneumonia (CABP). METHODS: Multiple diagnostic methods were employed to diagnose atypical infections including culture, serology, and urinary antigen. RESULTS: The microbiological intent-to-treat (MITT) population included 520 patients; 30% had an atypical bacterial pathogen identified (156/520). Overall, 13.1% (68/520) had a monomicrobial atypical infection and 2.3% (12/520) had polymicrobial all-atypical infections. Among patients with polymicrobial infections, Streptococcus pneumoniae was the most frequently occurring co-infecting organism and Chlamydia pneumoniae was the most frequently occurring co-infecting atypical organism. For Mycoplasma pneumoniae and Legionella pneumophila, serology yielded the highest number of diagnoses. Delafloxacin and moxifloxacin had similar in vitro activity against M. pneumoniae and delafloxacin had greater activity against L. pneumophila. Two macrolide-resistant M. pneumoniae isolates were recovered. No fluoroquinolone-resistant M. pneumoniae were isolated. The rates of microbiological success (documented or presumed eradication) at test-of-cure were similar between the delafloxacin and moxifloxacin groups. There was no evidence of a correlation between minimum inhibitory concentration (MIC) and outcome; a high proportion of favorable outcomes was observed across all delafloxacin baseline MICs. CONCLUSIONS: Delafloxacin may be considered a treatment option as monotherapy for CABP in adults, where broad-spectrum coverage including atypical activity is desirable.


Assuntos
Antibacterianos/administração & dosagem , Infecções Comunitárias Adquiridas/tratamento farmacológico , Fluoroquinolonas/administração & dosagem , Moxifloxacina/administração & dosagem , Pneumonia Bacteriana/tratamento farmacológico , Adulto , Infecções Comunitárias Adquiridas/microbiologia , Feminino , Humanos , Legionella pneumophila/efeitos dos fármacos , Legionella pneumophila/crescimento & desenvolvimento , Legionella pneumophila/isolamento & purificação , Macrolídeos/administração & dosagem , Masculino , Testes de Sensibilidade Microbiana , Mycoplasma pneumoniae/efeitos dos fármacos , Mycoplasma pneumoniae/crescimento & desenvolvimento , Mycoplasma pneumoniae/isolamento & purificação , Pneumonia Bacteriana/microbiologia , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/isolamento & purificação , Adulto Jovem
9.
J Mycol Med ; 30(3): 100985, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32418638

RESUMO

Aspergillus fumigatus can cause a wide range of diseases, from hypersensitivity to invasive infection. Invasive disease usually occurs in severely immunocompromised patients with deep and prolonged neutropenia. It is a less well-recognized complication in critically ill patients without traditional risk factors. We describe a case of early invasive pulmonary aspergillosis (IPA) secondary to Legionella pneumophila serogroup 1 pneumonia in a patient on an intensive care unit (ICU). In addition to commonly accepted risk factors for IPA in ICU patients, we hypothesis that L. pneumophilia pneumonia could enhance this type of infection. We also reviewed all published cases of coinfection with L. pneumophila and A. fumigatus to assess whether Legionnaires' disease could be a risk factor for IPA.


Assuntos
Estado Terminal , Aspergilose Pulmonar Invasiva/complicações , Aspergilose Pulmonar Invasiva/diagnóstico , Doença dos Legionários/complicações , Doença dos Legionários/diagnóstico , Idoso , Aspergillus fumigatus/isolamento & purificação , Diagnóstico Diferencial , França , Humanos , Unidades de Terapia Intensiva , Aspergilose Pulmonar Invasiva/microbiologia , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/microbiologia , Masculino
10.
Artigo em Inglês | MEDLINE | ID: mdl-32245064

RESUMO

Determination of Legionella concentrations in water networks is useful for predicting legionellosis risks. The standard culture technique using concentration with membranes filters is the most commonly used method for environmental surveillance of Legionella. The aim of this study was to verify whether filtration with different filter pore sizes (0.2 and 0.45 µm) according to (ISO) 11731:2017, followed by directly placing them on culture media, can influence Legionella detection. Three laboratories participated in an experimental study that tested a known suspension of Legionella pneumophila (Lpn) serogroup 1 (ATCC 33152) (approximate final cell density of 15 CFU/mL). E. coli (ATCC 11775) and Pseudomonas aeruginosa (ATCC 25668) were included as control tests. The average (95% CI) percentage of recovery of Lpn was 65% using 0.45-µm filters and 15% using 0.2-µm filters (p < 0.0001). For control tests, the average (95% CI) percentage of recovery was higher with 0.45 vs. 0.2 µm filters: 97% vs. 64% for Escherichia coli (p < 0.00001) and 105% vs. 97% (p = 0.0244) for P. aeruginosa. Our results showed that the 0.45-µm filters provided the greatest detection of Legionella. Because the current national guidelines leave the choice of membrane porosity to the operator, experimental studies are important for directing operators towards a conscious choice to standardize Legionella environmental surveillance methods.


Assuntos
Legionella pneumophila , Microbiologia da Água , Meios de Cultura , Escherichia coli/isolamento & purificação , Humanos , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/epidemiologia , Água , Abastecimento de Água
11.
Int J Infect Dis ; 93: 300-304, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32147537

RESUMO

OBJECTIVE: The feasibility of the decontamination procedure for Legionella pneumophila of water systems in healthcare facilities varies by water purification and disinfection methods in each country. We evaluated the efficacy of feasible decontamination strategies in Japan. METHODS: This study was conducted at Tokyo Medical University Hospital (1015 beds) between 2015 and 2018. Samples from the water system and cooling tower were cultured periodically. Hyper-chlorination of cool tap water (>0.2 ppm), increases in the temperature of hot water (>55 °C), and flushing were used as decontamination strategies. The case of healthcare-associated legionellosis was surveyed. Environmental and clinical isolates were genotyped. RESULTS: 1439 environmental samples were collected; 19 (1.3%) samples tested positive for L. pneumophila from water faucets of patient rooms, toilets, waste rooms, and water sourced from wells. Genotyping of 12 isolates confirmed that the same strains were present in eight environmental isolates and two isolates from patients over three years. Although the environmental contamination of the water system was persistent, the number of positive locations of hospital environments gradually decreased; eight in 2015, four in 2016, three in 2017, and four in 2018, respectively. CONCLUSIONS: Monitoring contamination, hyper-chlorination, controlling temperature, and flushing were effective as a Legionella decontamination strategy.


Assuntos
Equipamentos e Provisões Hospitalares/microbiologia , Legionella pneumophila/isolamento & purificação , Centros de Atenção Terciária , Microbiologia da Água , Purificação da Água/métodos , Abastecimento de Água , Desinfecção/métodos , Estudos de Viabilidade , Humanos , Japão , Legionelose/diagnóstico , Estudos Prospectivos
12.
Acta Crystallogr F Struct Biol Commun ; 76(Pt 3): 138-144, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32133999

RESUMO

Legionella pneumophila encodes an extracellular secreted phospholipase A named PlaA that is translocated by the type II secretion system. It plays an essential role in maintaining the integrity of Legionella-containing vacuoles in L. pneumophila pathogenesis. Here, it is shown that PlaA has a main lysophospholipase activity to hydrolyze fatty-acyl groups in lysophospholipids. Although it has a very low phospholipase A activity to catalyze the hydrolysis of fatty-acyl groups in phospholipids, PlaA can bind phospholipids such as 1,2-dipalmitoylphosphatidylcholine with a dissociation constant of 11.1 µM. Sequence-alignment analysis combined with activity assays revealed that PlaA contains a distinct substrate-binding site among the known structures of the phospholipase A family, implying that PlaA may present a novel mechanism for substrate recognition. Native PlaA and its selenomethionine (SeMet)-substituted form were purified and crystallized by vapour diffusion in hanging drops at 296 K. Diffraction data were collected to a resolution of 2.0 Šfor native PlaA protein and to a resolution of 2.7 Šfor SeMet-substituted PlaA protein. The crystals of native PlaA belonged to the monoclinic space group P21, while the crystals of SeMet-substituted PlaA belonged to the primitive orthorhombic space group P212121. Initial phases for PlaA were obtained from SeMet SAD data sets.


Assuntos
Proteínas de Bactérias/genética , Cristalização/métodos , Regulação Bacteriana da Expressão Gênica , Legionella pneumophila/genética , Proteínas/genética , Sequência de Aminoácidos , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/isolamento & purificação , Humanos , Legionella pneumophila/isolamento & purificação , Legionella pneumophila/metabolismo , Proteínas/isolamento & purificação , Proteínas/metabolismo
13.
J Infect Chemother ; 26(5): 411-417, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32081644

RESUMO

Legionella species are consistently identified as some of the most common causative agents of severe community-acquired pneumonia (CAP) or nosocomial pneumonia. Although the number of reported Legionella infection cases is gradually increasing in Japan, most cases are diagnosed by a urinary antigen test, which identifies only L. pneumophila serogroup 1. Therefore, assessment of pneumonia-causing Legionella species and serogroups would be important. The Japan Society for Chemotherapy Legionella committee has collected the isolates and clinical information on cases of sporadic community-acquired Legionella pneumonia throughout Japan. Between December 2006 and March 2019, totally 140 sporadic cases were identified, in which L. pneumophila was the most frequently isolated species (90.7%) followed by L. bozemanae (3.6%), L. dumofii (3.6%), L. micdadei (1.4%), and L. longbeachae (0.7%). Among 127 isolates of L. pneumophila, 111 isolates were of serogroup 1, two of serogroup 2, four of serogroup 3, one of serogroup 4, one of serogroup 5, seven of serogroup 6, and one was of serogroup 10. We also assessed in vitro activity of antibiotics against these isolates and showed that quinolones and macrolides have potent anti-Legionella activity. Our study showed that pneumonia-causing Legionella species and serogroup distribution was comparable to that reported in former surveillances. L. pneumophila was the most common etiologic agent in patients with community-acquired Legionella pneumonia, and L. pneumophila serogroup 1 was the predominant serogroup.


Assuntos
Legionella/classificação , Legionella/isolamento & purificação , Legionelose/microbiologia , Pneumonia Bacteriana/microbiologia , Idoso , Antibacterianos/uso terapêutico , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/microbiologia , Feminino , Humanos , Japão , Legionella pneumophila/classificação , Legionella pneumophila/isolamento & purificação , Legionelose/tratamento farmacológico , Doença dos Legionários/tratamento farmacológico , Doença dos Legionários/microbiologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Pneumonia Bacteriana/tratamento farmacológico , Sorogrupo , Sorotipagem
14.
MMWR Morb Mortal Wkly Rep ; 69(8): 207-211, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32106217

RESUMO

In January 2018, the Wisconsin Department of Health Services, Division of Public Health (DPH), received a report of a culture-confirmed case of Legionnaires' disease. The patient, who was immunocompromised, had died at a local hospital 10 days after being admitted. DPH and an infection preventionist from the hospital investigated to determine the source of the infection and prevent additional cases. Because the case was suspected to be nosocomial, health care facility water samples were tested for Legionella. When these samples were negative, water sources in the patient's home were tested. These tested positive for Legionella pneumophila, and the bacteria remained after an attempt to remediate. The patient and home isolates were identified as L. pneumophila serogroup 3, sequence type 93, by whole-genome multilocus sequence typing. A second resident of the home did not become ill. This case highlights the potential for immunocompromised persons and others at risk for Legionnaires' disease to be exposed to Legionella through home water systems containing the bacteria and demonstrates the difficulty of home remediation. This case also illustrates the role of lower respiratory tract specimens in the identification of less common Legionella infections (e.g., L. pneumophila serogroup 3) and confirmation of the infection source.


Assuntos
Exposição Ambiental/efeitos adversos , Habitação , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/diagnóstico , Idoso , Evolução Fatal , Humanos , Legionella pneumophila/classificação , Sorotipagem , Wisconsin
15.
Lett Appl Microbiol ; 70(4): 232-240, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31904109

RESUMO

Unregulated private wells are understudied potential sources of community-acquired Legionnaires' disease. Here we conducted a comprehensive survey of 44 homes supplied by private wells in Wake County, North Carolina, quantifying Legionella spp. DNA, Legionella pneumophila DNA, and total bacterial 16S rRNA genes via real-time polymerase chain reaction in hot and cold drinking water samples, along with culturable L. pneumophila via IDEXX Legiolert in cold drinking water samples. Legionella spp. DNA, L. pneumophila DNA and culturable L. pneumophila were detected in 100, 65·5 and 15·9% of the 44 homes, respectively, and culturable levels were comparable to some municipal surveys applying the same methods. Total coliforms and Escherichia coli were monitored as representative faecal indicators and were found in 20·4 and 0·0% of homes. Within certain sample types, Legionella spp. and L. pneumophila gene copy numbers were positively associated with total bacteria (i.e. total 16S rRNA genes) and water softener use, but were not associated with faecal indicator bacteria, inorganic water parameters or other well characteristics. These findings confirm that occurrence of Legionella and L. pneumophila is highly variable in private wells. SIGNIFICANCE AND IMPACT OF THE STUDY: Legionella is the leading identified cause of waterborne disease outbreaks associated with US municipal water systems. While Legionella is known to occur naturally in groundwater, prior efforts to characterize its occurrence in unregulated private wells are limited to sampling at the wellhead and not in the home plumbing where Legionella can thrive. This work documents much higher levels of Legionella in home plumbing versus water directly from private wells and examines factors associated with higher Legionella occurrence.


Assuntos
Água Potável/microbiologia , Legionella pneumophila/isolamento & purificação , DNA Bacteriano/genética , Humanos , Legionella pneumophila/classificação , Legionella pneumophila/genética , Doença dos Legionários/microbiologia , North Carolina , RNA Ribossômico 16S/genética , Engenharia Sanitária , Microbiologia da Água , Abastecimento de Água
16.
Artigo em Inglês | MEDLINE | ID: mdl-31947755

RESUMO

Legionnaires' disease (LD) is a severe pneumonia with a mortality rate of about 10%. The illness remains largely underdiagnosed with outbreaks occurring with alarming incidence. In this study, we assessed the frequency of Legionnaires' disease among pneumonia cases treated at a large community hospital over a summer season. We invited all admitted patients diagnosed with pneumonia, able to provide a urine sample for an antigen test, presenting from May to October 2018, to enroll in our study; 35 patients were tested for the presence of Legionella. Out of 33 patients tested, 9 (28%) were positive for Legionella. Three sets of the 9 Legionella cases exhibited spatiotemporal clustering indicative of LD outbreaks. Only one of the 9 Legionella UAT-positive patients presented a sporadic case of LD. The number of pneumonia cases in our community confirmed to be LD was strikingly high (28%), compared to other survey studies that report between 3.7% and 14%. These results are consistent with previous knowledge that LD is underdiagnosed and support that routine testing should be considered for all possible LD cases, particularly in the summer months. Such testing is likely to prevent further cases of community acquired LD.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Hospitais Comunitários/estatística & dados numéricos , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/diagnóstico , Doença dos Legionários/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Ontário/epidemiologia
17.
Int J Infect Dis ; 91: 174-176, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31707135

RESUMO

Three cases of pneumonia caused by Legionella pneumophila serogroup 1 (Lp1) in immunosuppressed patients with repeated hospitalization were suspected as a healthcare-associated cluster. The environmental investigation did not reveal the presence of legionellae in the hospital patient rooms. Water samples collected from the homes of two patients were also negative for Legionella spp. In the absence of environmental strains potentially involved in the infections, we proceeded to genotype environmental Lp1 strains isolated in the hospital during routine water sampling during the decade 2009-2019 and recovered after long-term storage at -20°C. These 'historical' strains exhibited a high grade of similarity and stability over time, regardless of the disinfection systems. The different molecular profiles shown among the clinical and environmental strains excluded a nosocomial outbreak. The study suggests that the application of molecular typing may be a useful tool to discriminate hospital vs community-acquired cases, mostly for severely immunosuppressed patients in whom the symptomatology could be insidious and the incubation period could be prolonged. Moreover, the genotyping allowed us to exclude any link between the cases.


Assuntos
Técnicas de Genotipagem , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/microbiologia , Idoso , Idoso de 80 Anos ou mais , Infecção Hospitalar/microbiologia , Surtos de Doenças , Feminino , Humanos , Imunossupressão , Legionella pneumophila/classificação , Legionella pneumophila/genética , Doença dos Legionários/epidemiologia , Doença dos Legionários/terapia , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , Sorogrupo
18.
Clin Microbiol Infect ; 26(4): 514.e1-514.e6, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31525518

RESUMO

OBJECTIVE: Legionella pneumophila serogroup 1 (Lp1) sequence type (ST) 1 is globally widespread in the environment and accounts for a significant proportion of Legionella infections, including nosocomial Legionnaires' disease (LD). This study aimed to design a sensitive and specific detection method for Lp ST1 that will underpin epidemiological investigations and risk assessment. METHODS: A total of 628 Lp genomes (126 ST1s) were analyzed by comparative genomics. Interrogation of more than 900 accessory genes revealed seven candidate targets for specific ST1 detection and specific primers and hydrolysis probes were designed and evaluated. The analytical sensitivity and specificity of the seven primer and probe sets were evaluated on serially diluted DNA extracted from the reference strain CIP107629 and via qPCR applied on 200 characterized isolates. The diagnostic performance of the assay was evaluated on 142 culture-proven clinical samples from LD cases and a real-life investigation of a case cluster. RESULTS: Of seven qPCR assays that underwent analytical validation, one PCR target (lpp1868) showed higher sensitivity and specificity for ST1 and ST1-like strains. The diagnostic performance of the assay using respiratory samples corresponded to a sensitivity of 95% (19/20) (95% CI (75.1-99.9)) and specificity of 100% (122/122) (95% CI (97-100)). The ST1 PCR assay could link two out of three culture-negative hospitalized LD cases to ST1 during a real-time investigation. CONCLUSION: Using whole genome sequencing (WGS) data, we developed and validated a sensitive and specific qPCR assay for the detection of Lp1 belonging to the ST1 clonal complex by amplification of the lpp1868 gene. The ST1 qPCR is expected to deliver an added value for Lp control and prevention, in conjunction with other recently developed molecular assays.


Assuntos
Legionella pneumophila/classificação , Doença dos Legionários/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Proteínas de Bactérias/genética , Primers do DNA/genética , Sondas de DNA , Genoma Bacteriano , Genômica , Genótipo , Humanos , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/microbiologia , Tipagem Molecular/métodos , Sensibilidade e Especificidade , Análise de Sequência de DNA , Sorogrupo , Sequenciamento Completo do Genoma
19.
Appl Microbiol Biotechnol ; 104(1): 405-415, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31832709

RESUMO

Recently Legionella pneumophila is the main causative waterborne organism of severe respiratory infections. Additionally, other Legionella species are documented as human pathogens. In our work, we describe a rapid detection method which combines two advantages for sensitive and specific detection of the genus Legionella: the fast isothermal amplification method "Loop-mediated isothermal AMPlification" (LAMP), and a colorimetric detection method using the metal indicator hydroxynaphtol blue (HBN) which allows to determine an optical signal with a simple readout (with the naked eye). Moreover, we present two approaches for minimizing the assay volume using a stationary microchip LAMP and droplet digital-based LAMP (ddLAMP) as promising highly sensitive setups.


Assuntos
Legionella pneumophila/isolamento & purificação , Legionella/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/métodos , Colorimetria , Primers do DNA/genética , Naftalenossulfonatos/metabolismo , Sensibilidade e Especificidade , Temperatura
20.
Epidemiol Infect ; 147: e326, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31858932

RESUMO

A cluster of Legionnaires' disease (LD) with 10 confirmed, three probable and four possible cases occurred in August and September 2016 in Dendermonde, Belgium. The incidence in the district was 7 cases/100 000 population, exceeding the maximum annual incidence in the previous 5 years of 1.5/100 000. Epidemiological, environmental and geographical investigations identified a cooling tower (CT) as the most likely source. The case risk around the tower decreased with increasing distance and was highest within 5 km. Legionella pneumophila serogroup 1, ST48, was identified in a human respiratory sample but could not be matched with the environmental results. Public health authorities imposed measures to control the contamination of the CT and organised follow-up sampling. We identified obstacles encountered during the cluster investigation and formulated recommendations for improved LD cluster management, including faster coordination of teams through the outbreak control team, improved communication about clinical and environmental sample analysis, more detailed documentation of potential exposures obtained through the case questionnaire and earlier use of a geographical information tool to compare potential sources and for hypothesis generation.


Assuntos
Surtos de Doenças , Legionella pneumophila/isolamento & purificação , Doença dos Legionários/epidemiologia , Microbiologia da Água , Adulto , Idoso , Bélgica/epidemiologia , Feminino , Humanos , Incidência , Doença dos Legionários/microbiologia , Doença dos Legionários/prevenção & controle , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
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