Search

BACKGROUND: Legionnaires disease is a common cause of adult pneumonia. Outbreaks of legionnaires disease have been well described, but little is known about sporadically occurring legionnaires disease, which accounts for most infections. Exposure to contaminated residential water sources is I plausible means of disease acquisition. METHODS: Employing a matched case-control study design in 15 hospitals in 2 Ohio counties, we prospectively enrolled 146 adults diagnosed as having nonepidemic, community-acquired legionnaires disease and compared each with 2 hospital-based control patients, matched for age, sex, and underlying illness category. An interview regarding potential exposures was followed by a home survey that included sampling residential sources for Legionella. Interview and home survey data were analyzed to estimate the risk of acquiring legionnaires disease associated with various exposures. RESULTS: Multivariate analysis showed that a nonmunicipal water supply (odds ratio [OR], 2.26; 95% confidence interval [CI], 1.17-4.37), recent residential plumbing repair (OR, 2.39; 95% CI, 1.10-5.18), and smoking (OR, 3.48; 95% CI, 2.09-5.79) were independent risk factors for legionnaires disease. Univariate analysis suggested that electric (vs gas) water heaters (OR, 1.97; 95% CI, 1.10-3.52), working more than 40 hours weekly (OR, 2.13; 95% CI, 1.12-4.07), and spending nights away from home before illness (OR, 1.68; 95% CI, 1.03-2.74) were additional possible risk factors. Lower chlorine concentrations in potable water and lower water heater temperatures were associated with residential Legionella colonization. CONCLUSIONS: A proportion of sporadic cases of legionnaires disease may be residentially acquired and are associated with domestic potable water and disruptions in residential plumbing systems. Potential strategies to reduce legionnaires disease risk include consistent chlorination of potable water, increasing water heater temperatures, and limiting exposure to aerosols after domestic plumbing repairs. [ABSTRACT FROM AUTHOR]

Background: Outbreaks of travel-related Legionnaires' disease present a public-health challenge since rapid, sensitive, and specific diagnostic tests are not widely used and because detection of clusters of disease among travellers is difficult. We report an outbreak of Legionnaires' disease among cruise ship passengers that occurred in April, 1994, but that went unrecognised until July, 1994.Methods: After rapid diagnosis of Legionnaires' disease in three passengers by urine antigen testing, we searched for additional cases of either confirmed (laboratory evidence of infection) or probable Legionnaires' disease (pneumonia of undetermined cause). A case-control study was conducted to compare exposures and activities on the ship and in ports of call between each case-passenger and two or three matched control-passengers. Water samples from the ship, from sites on Bermuda, and from the ship's water source in New York City were cultured for legionellae and examined with PCR.Findings: 50 passengers with Legionnaires' disease (16 confirmed, 34 probable) were identified from nine cruises embarking between April 30 and July 9, 1994. Exposure to whirlpool spas was strongly associated with disease (odds ratio 16.2, 95% Cl 2.8-351:7); risk of acquiring Legionnaires' disease increased by 64% (95% Cl 12-140) for every hour spent in the spa water. Passengers spending time around the whirlpool spas, but not in the water, were also significantly more likely to have acquired infection. Legionella pneumophila serogroup 1 was isolated only from the sand filter in the ship's whirlpool spa. This isolate matched a clinical isolate from the respiratory secretions of a case-passenger as judged by monoclonal antibody subtyping and by arbitrarily primed PCR.Interpretation: This investigation shows the benefit of obtaining a recent travel history, the usefulness or urine antigen testing for rapid diagnosis of legionella infection, and the need for improved surveillance for travel-related Legionnaires' disease. New strategies for whirlpool spa maintenance and decontamination may help to minimise transmission of legionellae from these aerosol-producing devices. [ABSTRACT FROM AUTHOR]

Balance relies on several types of sensory information, including somatosensory senses such as touch and position sense (proprioception). As these senses decline in older adults, there is a question of whether shoes limit somatosensory feedback from the floor. Textured insoles are designed to stimulate the soles of the feet to enhance tactile feedback. Textured insoles have shown balance benefits in some populations, but it is unclear if such tactile stimulation improves a person's balance even in cushioned athletic shoes, which dampen proprioceptive signals. Here we ask whether tactile vs. proprioceptive cues contribute differently to balance control in the healthy somatosensory system. We assessed balance in 20 healthy young adults under four footwear conditions: cushioned shoes with regular insoles, cushioned shoes with textured insoles, barefoot, and minimalist shoes. Each condition was evaluated using the Y-Balance Test (YBT) and the Balance Error Scoring System (BESS), validated tests of dynamic and static balance, respectively. YBT is a dynamic reaching test performed on one leg. The BESS includes various stance conditions with eyes closed. The results showed that footwear influenced dynamic balance only, with textured insoles leading to significantly better performance than barefoot and minimalist shoes did in the YBT. These results suggest that at least for dynamic balance, balance benefits of tactile stimulation from the textured insoles offset any dampening of proprioception caused by the athletic shoes' cushioning. Future research on how these conditions compare in older adults may lead to improved footwear recommendations to reduce fall risk and injuries for that population., (Copyright © 2022 Elsevier B.V. All rights reserved.)

A novel Legionella species was identified based on analysis of 16S rRNA and mip (macrophage infectivity potentiator) gene sequences, cellular fatty acids, isoprenoid quinones, biochemical reactions, antigens and quantitative DNA-DNA hybridization. Strain CDC-1796-JAP-E(T) was isolated from well water at the Nagasaki Municipal Medical Center, Japan. Two strains, CDC-3041-AUS-E and CDC-3558-AUS-E, were isolated from water samples during an outbreak of legionellosis in South Australia. Strain CDC-5427-OH-H was isolated from a 66-year-old female patient diagnosed with Legionnaires' disease in the US. Cells from these four strains were gram-negative, non-fluorescent, rod-shaped, and positive for alkaline phosphatase, esterase, leucine arylamidase, catalase, gelatinase, β-lactamase and tyrosine browning assay. Phylogenetic analysis of 16S rRNA and mip genes revealed that the four strains formed a distinct cluster within the genus Legionella. The bacteria contained branched-chain fatty acids and quinones that are typical of members of the genus Legionella. Slide agglutination tests demonstrated no cross-reaction with 52 previously described members of the Legionellaceae. DNA-DNA hybridization studies indicated that DNAs from the four strains were highly related (78-84 %) but they showed 29 % relatedness to Legionella oakridgensis ATCC 33761(T) and less than 10 % to strains of other Legionella species tested. These characterizations suggest that the isolates represent a novel species, for which the name Legionella nagasakiensis sp. nov. is proposed; the type strain is CDC-1796-JAP-E(T) ( = ATCC BAA-1557(T) = JCM 15315(T)).

Legionella longbeachae causes most cases of legionellosis in Australia and may be underreported worldwide due to the lack of L. longbeachae-specific diagnostic tests. L. longbeachae displays distinctive differences in intracellular trafficking, caspase 1 activation, and infection in mouse models compared to Legionella pneumophila, yet these two species have indistinguishable clinical presentations in humans. Unlike other legionellae, which inhabit freshwater systems, L. longbeachae is found predominantly in moist soil. In this study, we sequenced and annotated the genome of an L. longbeachae clinical isolate from Oregon, isolate D-4968, and compared it to the previously published genomes of L. pneumophila. The results revealed that the D-4968 genome is larger than the L. pneumophila genome and has a gene order that is different from that of the L. pneumophila genome. Genes encoding structural components of type II, type IV Lvh, and type IV Icm/Dot secretion systems are conserved. In contrast, only 42/140 homologs of genes encoding L. pneumophila Icm/Dot substrates have been found in the D-4968 genome. L. longbeachae encodes numerous proteins with eukaryotic motifs and eukaryote-like proteins unique to this species, including 16 ankyrin repeat-containing proteins and a novel U-box protein. We predict that these proteins are secreted by the L. longbeachae Icm/Dot secretion system. In contrast to the L. pneumophila genome, the L. longbeachae D-4968 genome does not contain flagellar biosynthesis genes, yet it contains a chemotaxis operon. The lack of a flagellum explains the failure of L. longbeachae to activate caspase 1 and trigger pyroptosis in murine macrophages. These unique features of L. longbeachae may reflect adaptation of this species to life in soil.

Approximately 84% of legionellosis cases are due to Legionella pneumophila serogroup 1. Moreover, a majority of L. pneumophila serogroup 1 clinical isolates react positively with monoclonal antibody 2 (MAb2) of the international standard panel. Over 94% of the legionellosis outbreaks investigated by the Centers for Disease Control and Prevention are due to this subset of L. pneumophila serogroup 1. To date, there is no complete explanation for the enhanced ability of these strains to cause disease. To better characterize these organisms, we subtyped 100 clinical L. pneumophila serogroup 1 isolates and 50 environmental L. pneumophila serogroup 1 isolates from the United States by (i) reactivity with MAb2, (ii) presence of a lag-1 gene required for the MAb2 epitope, and (iii) sequence-based typing analysis. Our results showed that the MAb2 epitope and lag-1 gene are overrepresented in clinical L. pneumophila serogroup 1 isolates. MAb2 recognized 75% of clinical isolates but only 6% of environmental isolates. Similarly, 75% of clinical isolates but only 8% of environmental isolates harbored lag-1. We identified three distinct lag-1 alleles, referred to as Philadelphia, Arizona, and Lens alleles, among 79 isolates carrying this gene. The Arizona allele is described for the first time in this study. We identified 59 different sequence types (STs), and 34 STs (58%) were unique to the United States. Our results support the hypothesis that a select group of STs may have an enhanced ability to cause legionellosis. Combining sequence typing and lag-1 analysis shows that STs tend to associate with a single lag-1 allele type, suggesting a hierarchy of virulence genotypes. Further analysis of ST and lag-1 profiles may identify genotypes of L. pneumophila serogroup 1 that warrant immediate intervention.

Background: Legionella species, Mycoplasma pneumoniae, and Chlamydia pneumoniae are recognized as important causes of pneumonia in high-income countries, but their significance in middle-income countries, such as Thailand, is unknown., Methods: Population-based surveillance identified inpatient 3489 cases of clinically-defined pneumonia in a rural Thai province for 1 year. Patients who had a chest radiograph performed (for 2059 cases of pneumonia) were enrolled in an etiology study (which included 755 cases of pneumonia among 738 patients). Paired serum, nasopharyngeal swab, and urine specimens were obtained for diagnostic immunologic and molecular tests. Patients aged <18 years were not systematically tested for Legionella species. We report a lower limit of incidence (observed incidence) and an upper limit extrapolated to persons not tested or not enrolled in the study., Results: The incidence of pneumonia due to Legionella longbeachae requiring hospitalization was 5-29 cases per 100,000 population. No case of Legionella pneumophila pneumonia was observed. The definite C. pneumoniae pneumonia incidence was 3-23 cases per 100,000 population; rates were highest among patients aged <1 year (18-166 cases per 100,000 population) and those aged >or=70 years (23-201 cases per 100,000 population). M. pneumoniae pneumonia had a similar age distribution, with an overall incidence of 6-44 cases per 100,000 population. These pathogens were associated with 15% of all cases of pneumonia. A nonsignificantly higher proportion of patients with pneumonia associated with L. longbeachae, compared with patients with pneumonia associated with M. pneumoniae or C. pneumoniae, required supplemental oxygen or mechanical ventilation (45% vs. 18%; P<.1). Among patients with atypical pneumonia, only 15% received antibiotics with activity against the associated pathogen., Conclusion: M. pneumoniae, C. pneumoniae, and L. longbeachae, but not L. pneumophila, are frequently associated with severe pneumonia in rural Thailand. Few patients receive antibiotics that cover atypical pathogens.

Background: From June to November 2005, 18 cases of community-acquired Legionnaires' disease (LD) were reported in Rapid City South Dakota. We conducted epidemiologic and environmental investigations to identify the source of the outbreak., Methods: We conducted a case-control study that included the first 13 cases and 52 controls randomly selected from emergency department records and matched on underlying illness. We collected information about activities of case-patients and controls during the 14 days before symptom onset. Environmental samples (n = 291) were cultured for Legionella. Clinical and environmental isolates were compared using monoclonal antibody subtyping and sequence based typing (SBT)., Results: Case-patients were significantly more likely than controls to have passed through several city areas that contained or were adjacent to areas with cooling towers positive for Legionella. Six of 11 case-patients (matched odds ratio (mOR) 32.7, 95% CI 4.7-infinity) reported eating in Restaurant A versus 0 controls. Legionella pneumophila serogroup 1 was isolated from four clinical specimens: 3 were Benidorm type strains and 1 was a Denver type strain. Legionella were identified from several environmental sites including 24 (56%) of 43 cooling towers tested, but only one site, a small decorative fountain in Restaurant A, contained Benidorm, the outbreak strain. Clinical and environmental Benidorm isolates had identical SBT patterns., Conclusion: This is the first time that small fountain without obvious aerosol-generating capability has been implicated as the source of a LD outbreak. Removal of the fountain halted transmission.

Background: A long-term care facility (LTCF) reported an outbreak of Legionnaires' disease (LD) in September 2004., Methods: We conducted case finding through enhanced surveillance, medical record review (n = 131), and community surveys (n = 258). We cultured water samples from the LTCF and assayed their outdoor air-intake filters for Legionella DNA. We also investigated a cooling tower, the only nearby outdoor aerosol source., Results: Among 7 confirmed cases, 2 LTCF residents never exited, and 2 community residents never entered the LTCF during the incubation period. Among 63 water and biofilm samples collected from throughout the LTCF, we found no evidence of Legionella colonization, either in the potable water or air-handling systems. Conversely, we isolated a common outbreak-causing strain of Legionella pneumophila serogroup 1 from an industrial cooling tower located 0.4 km from the LTCF and recovered L pneumophila DNA from the LTCF's outdoor air-intake filters, suggesting that aerosolized Legionella from the cooling tower most likely entered the LTCF through the air-intake system or, possibly, through open windows., Conclusion: Residents of LTCFs can acquire LD from community sources. A cluster of LD cases among LTCF residents does not necessarily indicate transmission from within the LTCF.

Background: During March 2004, a large outbreak of legionnaires disease and Pontiac fever occurred among hotel guests in Oklahoma. An investigation was conducted to identify the source and evaluate the utility of the Legionella urine antigen assay and serologic testing for the identification of Pontiac fever., Methods: A retrospective cohort investigation of hotel guests and employees and an environmental evaluation were performed. Participants were interviewed, and clinical specimens were collected from consenting individuals., Results: Six cases of legionnaires disease and 101 cases of Pontiac fever were identified. Exposure to the indoor pool and hot tub area was associated with legionellosis (relative risk, 4.4; 95% confidence interval, 2.8-6.9). Specimens from the pool and hot tub tested positive for Legionella pneumophila serogroup 1 by polymerase chain reaction. For Pontiac fever, the sensitivity and positive predictive value were 35.7% and 100%, respectively, for the urine antigen assay, and 46.4% and 90%, respectively, for serologic testing. The specificity and negative predictive value were 100% and 47.8%, respectively, for the urine antigen assay, and 89.3% and 45.5%, respectively, for serologic testing., Conclusions: Urine antigen testing, with or without serologic testing, can be used to confirm outbreak-associated cases of Pontiac fever caused by L. pneumophila serogroup 1.

Aims: To validate identification methods for Legionella pneumophila strains that cannot be serotyped into the known serogroups and to characterize their antigenic diversity., Methods and Results: Fifty L. pneumophila strains that could not be serogrouped, but which had been confirmed as L. pneumophila by mip gene sequencing, were further identified phenotypically. We used (i) MONOFLUO anti-Legionella Staining Reagent (Bio-Rad) (50/50), (ii) an in-house prepared immunoblot assay for the detection of L. pneumophila- specific Mip protein epitope (50/50), (iii) fatty acid analysis using the Microbial Identifications System (MIDI) (47/50) and (iv) Oxoid agglutination tests (44/50). The serological diversity was further characterized by testing with five serogroup-cross-reactive monoclonal antibodies, resulting in nine phenons., Conclusions: The division of L. pneumophila into 15 serogroups does not reflect the serogroup heterogeneity. Results of these tests indicate that there are more serogroups., Significance and Impact of the Study: MONOFLUO anti-Legionella Staining Reagent is the only commercially available tool for identifying atypical strains of L. pneumophila. If necessary for epidemiological purposes, the antigenic heterogeneity of these strains can be analysed by monoclonal antibodies.

Objectives: To characterize illness and identify the etiology for two nursing home outbreaks of respiratory illness., Design: Multisite outbreak investigations; cohort., Setting: Two nursing homes in Pennsylvania., Participants: Facility A residents (n = 170), Facility B residents (n = 124), and employees (n = 91)., Measurements: Medical records for Facility A and B residents were reviewed, and employees from Facility B self-administered a questionnaire to identify risk factors for illness. Serological, oropharyngeal, and nasopharyngeal specimens were collected for both outbreaks, and testing for respiratory pathogens was performed., Results: In Facility A, 40 (24%) of 170 residents were identified with respiratory illness; 13 (33%) case-patients had radiographically confirmed pneumonia, 15 (38%) were taken to a hospital, and two (5%) died. Of 10 specimens collected from symptomatic Facility A case-patients, four (40%) tested positive using reverse transcription polymerase chain reaction for rhinovirus. In Facility B, 77 (62%) of 124 residents had respiratory illness, and 40 (52%) had radiographically confirmed pneumonia; 12 (16%) case-patients were hospitalized, and five (6%) died. Of 19 respiratory specimens collected from symptomatic Facility B case-patients, six (32%) were positive for rhinovirus; one was from an employee. Five (50%) of 10 rhinovirus-positive cases in both outbreaks had clinical and radiographic evidence of pneumonia., Conclusion: These investigations suggest that rhinoviruses may be an underrecognized cause of respiratory outbreaks in nursing homes, capable of causing pneumonia and perhaps death.

We investigated 3 cases of legionnaires disease (LD) that developed in travelers who stayed at a hotel in the United States Virgin Islands where cases of LD occurred in 1981-1982 and in 1998. The temperature of the potable water at the hotel was in a range that could optimally support the growth of Legionella species, and the potable water was colonized with Legionella pneumophila in 1981-1982 and in 2002-2003.

In response to the emergence of severe acute respiratory syndrome (SARS), the United States established national surveillance using a sensitive case definition incorporating clinical, epidemiologic, and laboratory criteria. Of 1,460 unexplained respiratory illnesses reported by state and local health departments to the Centers for Disease Control and Prevention from March 17 to July 30, 2003, a total of 398 (27%) met clinical and epidemiologic SARS case criteria. Of these, 72 (18%) were probable cases with radiographic evidence of pneumonia. Eight (2%) were laboratory-confirmed SARS-coronavirus (SARS-CoV) infections, 206 (52%) were SARS-CoV negative, and 184 (46%) had undetermined SARS-CoV status because of missing convalescent-phase serum specimens. Thirty-one percent (124/398) of case-patients were hospitalized; none died. Travel was the most common epidemiologic link (329/398, 83%), and mainland China was the affected area most commonly visited. One case of possible household transmission was reported, and no laboratory-confirmed infections occurred among healthcare workers. Successes and limitations of this emergency surveillance can guide preparations for future outbreaks of SARS or respiratory diseases of unknown etiology.

This case-control study investigated a cluster of respiratory illness among patrons of a restaurant. Of 173 patrons interviewed, 117 (68%) were ill. Symptoms included myalgias (93%), headache (87%), and fatigue (79%). The mean incubation period was 49 h and the mean duration of illness was 71 h. Patrons aged >15 years were more likely to have been ill than younger patrons (odds ratio [OR], 2.96; P=.002); 58% of persons who were ill sat near a large fountain, compared with 18% of respondents who were not ill (OR, 7.5; P=.005). Legionella anisa was cultured from water samples obtained from the fountain pool. Of 22 individuals who were ill, 11 (50%) had a > or =4-fold increase in the titer of antibody to that strain of L. anisa from acute-phase to convalescent-phase serum samples; 3 others (14%) had persistently elevated titers of > or =512; of a group of 20 individuals who had not been exposed to the restaurant, none had titers of >128. Pontiac fever should be considered as a diagnosis during acute outbreaks of influenza-like illness with a high attack rate and no other identified etiology.

Agricultural crops can be used either to remediate selenium-contaminated soils or to increase the daily selenium intake of consumers after soil supplementation using inorganic or organic selenium sources. In this study, four agricultural crops were examined for potential selenium enhancement. Soils containing tomato, strawberry, radish, and lettuce plants were supplemented with either an inorganic or an organic form of selenium. Two different soils, i.e., low Se and high Se containing, were also used. Statistically significant differences in appearance, fruit production, and fresh weights of the fruit produced were studied. Next, the amount of selenium retained in the edible fruits, nonedible plant, and soil for each was analyzed by acid digestion followed by hydride generation atomic absorption analysis. Finally, inhibition effects on the seeds of the agricultural plants were studied. The results show that supplementation with an inorganic form of selenium led to higher retention in the plants, with a maximum of 97.5% retained in the edible portion of lettuce plants.

Previous work has established the possibility of using known coordinating agents supported on silica gel in the removal of heavy metals such as lead, copper, cadmium, and nickel from aqueous media. Functionalized silica gel has been used in the removal of heavy metals with notable success. Silica gel is currently being used as a support for various monofunctional aliphatic amines as coordinating ligands. The current study reports the results of an investigation involving the use of saturated, straight chain primary amines as coordinating ligands in the removal of copper(II), cadmium(II), lead(II), nickel(II), and silver(I) ions from aqueous solutions of known concentration. Primary amines used in this investigation were n-butylamine, n-hexylamine, n-octylamine, n-decylamine, and n-hexadecylamine.

New diagnostic tests and empirical therapy for pneumonia may have important ramifications for the identification, treatment, and control of legionnaires disease (LD). To determine trends in the epidemiology of LD, we analyzed data for 1980-1998 from the passive surveillance system of the Centers for Disease Control and Prevention. During this time period, there were 6757 confirmed cases of LD (median annual number, 360 cases/year). Diagnosis by culture and by direct fluorescent antibody and serologic testing decreased significantly; diagnosis by urine antigen testing increased from 0% to 69%. The frequency of isolates other than Legionella pneumophila serogroup 1 (LP1) decreased from 38% to 4% (P=.003). The case-fatality rate decreased significantly, from 34% to 12% (P<.001) for all cases, from 46% to 14% (P<.0001) for nosocomial cases, and from 26% to 10% (P=.05) for community-acquired cases. LD-related mortality has decreased dramatically. The decrease in culture-based diagnosis limits the recognition of non-LP1 disease and impairs outbreak investigation, because fewer Legionella isolates are provided for further examination.

The bioterrorism-associated human anthrax epidemic in the fall of 2001 highlighted the need for a sensitive, reproducible, and specific laboratory test for the confirmatory diagnosis of human anthrax. The Centers for Disease Control and Prevention developed, optimized, and rapidly qualified an enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) antibodies to Bacillus anthracis protective antigen (PA) in human serum. The qualified ELISA had a minimum detection limit of 0.06 micro g/mL, a reliable lower limit of detection of 0.09 micro g/mL, and a lower limit of quantification in undiluted serum specimens of 3.0 micro g/mL anti-PA IgG. The diagnostic sensitivity of the assay was 97.8%, and the diagnostic specificity was 97.6%. A competitive inhibition anti-PA IgG ELISA was also developed to enhance diagnostic specificity to 100%. The anti-PA ELISAs proved valuable for the confirmation of cases of cutaneous and inhalational anthrax and evaluation of patients in whom the diagnosis of anthrax was being considered.

Saturated, straight chain mercaptans were attached to silica gel and used as coordinating agents for removal of cadmium(II), copper(II), lead(II), and nickel(II) ions from standard solutions. It is believed that the mercaptans become wedged in the silica pores, but are available for reaction. Four thiols were used, viz., 1-hexanethiol, 1-dodecanethiol, 1-hexadecanethiol, and 1-octadecanethiol. Standard solutions of metals (1.57 mM) were stirred with the supported mercaptans for two hours, and at 25 degrees C, and the sample supernatants were analyzed using atomic absorption spectrometry. At pH = 8, the percent removal was 99 (Cd), 91.5 (Cu), 80.8 (Pb), and 97 (Ni). It was possible to acidify the metal-containing solids, and regenerate the supported chelating agents.

Investigation of lead levels in Delaney Creek, which flows through a former lead-acid battery manufacturing and disposal site in Tampa, FL, revealed low but significant lead levels in the water and sediments along the creek, Known phytoaccumulator plants populate certain locations within the creek and adjacent wetlands. Three representative plants from the study site--cattail (Typha domingensis Pers.), hydrilla (Hydrilla verticillata Royle), and duckweed (Lemna obscura L.)--were investigated for their potential to remove lead from contaminated waters under the controlled conditions of a phytotron room. The plants were collected at the site and cultured in hydroponic medium under conditions that mimicked their natural environment (26 degrees C and 80% humidity). Results indicate that, of the three species, duckweed and hydrilla achieve high lead removal efficiencies after a short exposure period (98% removal using hydrilla, 97% with duckweed after one week of exposure) while cattail appears to be less efficient than the other two species. The kinetic rates of lead removal were studied for Lemna obscura.

There is still a low level of clinical awareness regarding Legionnaires' disease 25 years after it was first detected. The causative agents, legionellae, are freshwater bacteria with a fascinating ecology. These bacteria are intracellular pathogens of freshwater protozoa and utilize a similar mechanism to infect human phagocytic cells. There have been major advances in delineating the pathogenesis of legionellae through the identification of genes which allow the organism to bypass the endocytic pathways of both protozoan and human cells. Other bacteria that may share this novel infectious process are Coxiella burnetti and Brucella spp. More than 40 species and numerous serogroups of legionellae have been identified. Most diagnostic tests are directed at the species that causes most of the reported human cases of legionellosis, L. pneumophila serogroup 1. For this reason, information on the incidence of human respiratory disease attributable to other species and serogroups of legionellae is lacking. Improvements in diagnostic tests such as the urine antigen assay have inadvertently caused a decrease in the use of culture to detect infection, resulting in incomplete surveillance for legionellosis. Large, focal outbreaks of Legionnaires' disease continue to occur worldwide, and there is a critical need for surveillance for travel-related legionellosis in the United States. There is optimism that newly developed guidelines and water treatment practices can greatly reduce the incidence of this preventable illness.

Travel-associated outbreaks of legionnaires disease (LD) and combined outbreaks of LD and Pontiac fever (PF) are rarely identified. During one travel-associated combined outbreak at a hotel, a cohort study of potentially exposed persons and an environmental investigation were performed. Two LD and 22 PF cases were identified. Legionella pneumophila serogroup 6 (Lp6) isolates from the index patient and the hotel whirlpool spa were found to be identical by amplified fragment-length polymorphism typing. Disease occurred in 10 of 26 guests who were exposed to the spa versus 2 of 29 guests who were exposed only to the pool area (38% vs. 7%; P=.005). Immunoglobulin M (IgM) antibody to the outbreak Lp6 strain was more common among persons with PF (4 of 9) than among non-ill persons (2 of 32) (44% vs. 6%; P=.02). Spa exposure correlated with disease (P=.001) and IgM seropositivity (P=.007). New laboratory techniques facilitate outbreak investigation; to expedite outbreak interruption and measure the impact of travel-associated legionellosis, surveillance must be improved.

Novel Legionella-like isolates, strains Montbéliard A1T and Gréoux 11 D13T, isolated from two different French water sources, were studied taxonomically and phylogenetically. Morphological and biochemical characterization revealed that they were Gram-negative, aerobic, non-spore-forming bacilli with a cut-glass appearance that grew only on L-cysteine-supplemented buffered charcoal yeast extract agar. Phenotypic characterization using fatty acid and ubiquinone profiles and SDS-PAGE analysis confirmed that they were closely related, but distinct from, other species of the genus Legionella, since serotyping could not relate them to any existing serogroup. Genotypic profiles generated by randomly amplified polymorphic DNA and 16S-23S rDNA spacer region PCR analyses were unique for each of these isolates. DNA-DNA relatedness values of strains Montbéliard A1T and Gréoux 11 D13T to each other and to other Legionella type strains were less than 25%. Phylogenetic affiliation of these organisms obtained by 16S rDNA sequence comparisons confirmed that they were distinct from any other known Legionella species. All the above results confirm that these strains constitute two novel species for which the names Legionella gresilensis sp. nov. (type strain Gréoux 11 D13T = ATCC 700509T = CIP 106631T) and Legionella beliardensis sp. nov. (type strain Montbéliard A1T = ATCC 700512T = CIP 106632T) are proposed.

Seven strains of Legionella-like amoebal pathogens (LLAPs) were characterized on the basis of their cultural and staining characteristics, biochemical reactions, serology, cellular fatty acids (CFAs), isoprenoid quinone composition, total DNA relatedness, analysis of 16S rRNA and macrophage infectivity potentiator (mip) gene sequence analyses. All seven strains exhibited limited growth on buffered charcoal yeast extract alpha (BCYE) agar, required cysteine for growth and contained branched-chain CFAs and quinones typical of Legionella species. The bacilli were Gram-negative and catalase-positive. There were varying degrees of serological cross-reactions between these LLAP strains and other previously described Legionella species. Results from the various tests revealed that four LLAP strains represent three unusual new species of Legionella: Legionella drozanskii sp. nov., type strain LLAP-1T; Legionella rowbothamii sp. nov., type strain LLAP-6T; and Legionella fallonii sp. nov., type strain LLAP-10T. Three other LLAP strains, designated LLAP-7FL, LLAP-7NF and LLAP-9, were shown to be members of the species Legionella lytica. The deductions made from the phenetic characteristics of these bacteria were consistent with the phylogenetic relationships inferred from 16S rRNA and mip gene sequence analyses. This study is the first to speciate LLAP strains on the basis of data including quantitative DNA hybridization.

This work explores surface interactions between stabilized gypsum and nitric oxide. Gypsum is a common air-borne mineral particulate that has a potential two-fold relationship to the air pollution problem: as a particulate pollutant and as a catalyst or adsorbent for pollutant gases. Nitric Oxide is found in stack gases and automotive exhausts. Isotherms of nitric oxide adsorbed on stabilized gypsum were studied at 24 degrees C, 0 degree C, and -78 degrees C. Coverages were related to a monolayer based upon a surface area of 17.0 m2/g as determined from a nitrogen adsorption isotherm and the B.E.T. method. Multilayer coverages containing both reversible and irreversible adsorption were observed for nitric oxide adsorbed on stabilized hydrated calcium sulfate. An irreversible coverage of 41% at 24 degrees C and 61% at 0 degree C of the nitrogen monolayer was observed for nitric oxide adsorbed on hydration stabilized gypsum. The heat of adsorption at zero coverage was found to be 80.4 kJ/mol for nitric oxide on stabilized hydrated calcium sulfate for the irreversible adsorption and 7.5 kJ/mol for the reversible adsorption.

An epidemiological and microbiological investigation of a cluster of eight cases of Legionnaires' disease in Los Angeles County in November 1997 yielded conflicting results. The epidemiological part of the investigation implicated one of several mobile cooling towers used by a film studio in the centre of the outbreak area. However, water sampled from these cooling towers contained L. pneumophila serogroup 1 of another subtype than the strain that was recovered from case-patients in the outbreak. Samples from two cooling towers located downwind from all of the case-patients contained a Legionella strain that was indistinguishable from the outbreak strain by four subtyping techniques (AP-PCR, PFGE, MAb, and MLEE). It is unlikely that these cooling towers were the source of infection for all the case-patients, and they were not associated with risk of disease in the case-control study. The outbreak strain also was not distinguishable, by three subtyping techniques (AP-PCR, PFGE, and MAb), from a L. pneumophila strain that had caused an outbreak in Providence, RI, in 1993. Laboratory cross-contamination was unlikely because the initial subtyping was done in different laboratories. In this investigation, microbiology was helpful for distinguishing the outbreak cluster from unrelated cases of Legionnaires' disease occurring elsewhere. However, multiple subtyping techniques failed to distinguish environmental sources that were probably not associated with the outbreak. Persons investigating Legionnaires' disease outbreaks should be aware that microbiological subtyping does not always identify a source with absolute certainty.

Background: Recognized outbreaks of Legionnaires' disease (LD) are rare; when they occur, they provide opportunities to understand the epidemiology of the illness and improve prevention strategies. We investigated a population-based outbreak., Methods: After the confirmation of LD in October 1996 in five people in neighbouring towns in southwest Virginia, active surveillance for additional cases was undertaken. A case-control study was conducted to identify exposures associated with illness, followed by a cohort study among employees of the facility at which the source of the outbreak was located in order to assess unrecognized exposure and illness. Samples of likely sources of LD in the facility were cultured for LEGIONELLA:, Results: In all, 23 laboratory-confirmed cases of LD were eventually identified. Of the 15 cases in the case-control study, 14 (93%) reported visiting a home-improvement store, compared with 12 (27%) of 45 controls (matched odds ratio [MOR] = 23.3; 95% CI : 3-182). Among home-improvement centre patrons, 10 (77%) of 13 cases questioned recalled either visiting or walking by a display whirlpool spa, compared with 3 (25%) of 12 controls (MOR = 5.5; 95% CI : 0.7-256.0). Two cases' sputum isolates were an exact match, by monoclonal antibody subtyping and arbitrarily primed polymerase chain reaction, to a whirlpool spa filter isolate from the store. Employees reporting more exposure to the display spas were more likely to report symptoms of LD or to have an elevated titre., Conclusions: This investigation shows that LD can be transmitted from a whirlpool spa used for display only, and highlights the need for minimizing the risk of transmission of LD from all water-filled spas. Key messages This paper describes an investigation of a population-based outbreak of Legionnaires' disease (LD). A case-control study first identified a home-improvement store as the likely source of the outbreak. An environmental investigation later confirmed that finding, as two cases' sputum isolates were an exact match, by monoclonal antibody subtyping and arbitrarily primed polymerase chain reaction, to a whirlpool spa filter isolate from the store. The spa was intended and used for display only.

The Binax and the Biotest urinary antigen kits for the detection of Legionnaires' disease caused by organisms other than Legionella pneumophila were compared by testing 45 urine samples from non-Legionella pneumophila serogroup 1 patients previously positive in a broad-spectrum enzyme-linked immunosorbent assay (ELISA). Eighteen were positive with the Binax kit, and 13 were positive with the Biotest. Although neither kit is as sensitive as ELISA, these results extend the number of serogroups and species of Legionella that can be diagnosed with the Binax or Biotest kit.

Objective: To investigate an increase in reports of legionnaires' disease by multiple hospitals in San Antonio, Texas, and to study risk factors for nosocomial transmission of legionnaires' disease and determinants for Legionella colonization of hospital hot-water systems., Setting: The 16 largest hospitals in the cities of San Antonio, Temple, and Austin, Texas., Design: Review of laboratory databases to identify patients with legionnaires' disease in the 3 years prior to the investigation and to determine the number of diagnostic tests for Legionella performed; measurement of hot-water temperature and chlorine concentration and culture of potable water for Legionella. Exact univariate calculations, Poisson regression, and linear regression were used to determine factors associated with water-system colonization and transmission of Legionella., Results: Twelve cases of nosocomial legionnaires' disease were identified; eight of these occurred in 1996. The rise in cases occurred shortly after physicians started requesting Legionella urinary antigen tests. Hospitals that frequently used Legionella urinary antigen tests tended to detect more cases of legionnaires' disease. Legionella was isolated from the water systems of 11 of 12 hospitals in San Antonio; the 12th had just experienced an outbreak of legionnaires' disease and had implemented control measures. Nosocomial legionellosis cases probably occurred in 5 hospitals. The number of nosocomial legionnaires' disease cases in each hospital correlated better with the proportion of water-system sites that tested positive for Legionella (P=.07) than with the concentration of Legionella bacteria in water samples (P=.23). Hospitals in municipalities where the water treatment plant used monochloramine as a residual disinfectant (n=4) and the hospital that had implemented control measures were Legionella-free. The hot-water systems of all other hospitals (n=11) were colonized with Legionella. These were all supplied with municipal drinking water that contained free chlorine as a residual disinfectant. In these contaminated hospitals, the proportion of sites testing positive was inversely correlated with free residual chlorine concentration (P=.01). In all hospitals, hot-water temperatures were too low to inhibit Legionella growth., Conclusions: The increase in reporting of nosocomial legionnaires' disease was attributable to increased use of urinary antigen tests; prior cases may have gone unrecognized. Risk of legionnaires' disease in hospital patients was better predicted by the proportion of water-system sites testing positive for Legionella than by the measured concentration of Legionella bacteria. Use of monochloramine by municipalities for residual drinking water disinfection may help prevent legionnaires' disease.

Objective: To investigate a cluster of cases of legionnaires' disease among patients at a hospital., Setting: A university hospital that is a regional transplant center., Design: Retrospective review of microbiology and serology data from the hospital laboratories and prospective surveillance via the radiology department; a case-control study and environmental sampling within the hospital and from nearby cooling towers., Results: Diagnosis of seven cases of legionnaires' disease in the first 9 months of 1996 led to recognition of a nosocomial outbreak that may have begun as early as 1979. Review of charts from 1987 through September 1996 identified 25 culture-confirmed cases of nosocomial or possibly nosocomial legionnaires' disease, including 18 in bone marrow and heart transplant patients. Twelve patients (48%) died. During the first 9 months of 1996, the attack rate was 6% among cardiac and bone marrow transplant patients. For cases that occurred before 1996, intubation was associated with increased risk for disease. High-dose corticosteroid medication was strongly associated with the risk for disease, but other immunosuppressive therapy or cancer chemotherapy was not. Several species and serogroups of Legionella were isolated from numerous sites in the hospital's potable water system. Six of seven available clinical isolates were identical and were indistinguishable from environmental isolates by pulsed-field gel electrophoresis. Initial infection control measures failed to interrupt nosocomial acquisition of infection. After extensive modifications to the water system, closely monitored repeated hyperchlorinations, and reduction of patient exposures to aerosols, transmission was interrupted. No cases have been identified since September 1996., Conclusions: Legionella can colonize hospital potable water systems for long periods of time, resulting in an ongoing risk for patients, especially those who are immunocompromised. In this hospital, nosocomial transmission possibly occurred for more than 17 years and was interrupted in 1996, after a sudden increase in incidence led to its recognition. Hospitals specializing in the care of immunocompromised patients (eg, transplant centers) should prioritize surveillance for cases of legionnaires' disease. Aggressive control measures can interrupt transmission of this disease successfully.

Background: In 1994, a hospital reported an increase in nosocomial legionnaires' disease after implementing use of a rapid urinary antigen test for Legionella pneumophila serogroup 1 (Lp-1). This hospital was the site of a previous nosocomial legionnaires' disease outbreak during 1980 to 1982., Methods: Infection control records were reviewed to compare rates of nosocomial pneumonia and the proportion of cases attributable to legionnaires' disease during the 1994 outbreak period with those during the same period in 1993. Water samples were collected for Legionella culture from the hospital's potable water system and cooling towers, and isolates were subtyped by monoclonal antibody (MAb) testing and arbitrarily primed polymerase chain reaction (AP-PCR)., Results: Nosocomial pneumonia rates were similar from April through October 1993 and April through October 1994: 5.9 and 6.6 per 1,000 admissions, respectively (rate ratio [RR], 1.1; P=.56); however, 3.2% of nosocomial pneumonias were diagnosed as legionnaires' disease in 1993, compared with 23.9% in 1994 (RR, 9.4; P<.001). In 1994, most legionnaires' disease cases were detected by the urinary antigen testing alone. MAb testing and AP-PCR demonstrated identical patterns among Lp-1 isolates recovered from a patient's respiratory secretions, the hospital potable water system, and stored potable water isolates from the 1980 to 1982 outbreak., Conclusions: There may have been persistent transmission of nosocomial legionnaires' disease at this hospital that went undiscovered for many years because there was no active surveillance for legionnaires' disease. Introduction of a rapid urinary antigen test improved case ascertainment. Legionella species can be established in colonized plumbing systems and may pose a risk for infection over prolonged periods.

There are currently 42 described species of legionellae representing 64 serogroups in the family Legionellaceae and the genus Legionella. The phenotypic characteristics of legionellae are described, including growth requirements, and biochemical characteristics. Identification of legionellae by biochemical tests, fatty acid analysis, ubiquinones, protein profiles, carbohydrate analysis, serology, monoclonal antibodies, and molecular techniques is described. The occurrence and description of Legionella-like amebic pathogens are discussed. The problems of identification to the species level are discussed, along with the need for further evaluations of additional strains from all known species using biochemical and molecular techniques.

There are numerous in vitro studies documenting the multiplication of Legionella species in free-living amoebae and other protozoa. It is believed that protozoa serve as host cells for the intracellular replication of certain Legionella species in a variety of environmental settings. This study describes the isolation and characterization of a bacterium initially observed within an amoeba taken from a soil sample. In the laboratory, the bacterium multiplied within and was highly pathogenic for Acanthamoeba polyphaga. Extracellular multiplication was observed on buffered charcoal yeast extract agar but not on a variety of conventional laboratory media. A 16S rRNA gene analysis placed the bacterium within the genus Legionella. Serological studies indicate that it is distinct from previously described species of the genus. This report also describes methods that should prove useful for the isolation and characterization of additional Legionella-like bacteria from free-living amoebae. In addition, the characterization of bacterial pathogens of amoebae has significant implications for understanding the ecology and identification of other unrecognized bacterial pathogens.

In July 1995 we investigated a pneumonia outbreak in a Pennsylvania town. We conducted epidemiological and molecular microbiological studies to determine the outbreak source and interrupt transmission of disease. Legionnaires' disease (LD) was quickly identified by urine antigen testing, and a newly developed immunohistochemical stain confirmed nosocomial transmission to a hospital inpatient. LD was confirmed in 22 patients. Case-patients were more likely than controls to have been within 1,000 feet of the hospital (matched odds ratio, 21.0; 95% confidence interval, 2.9-368) during the 2 weeks prior to illness. Legionella pneumophila serogroup 1 (Lp-1) was isolated from hospital cooling towers (CTs) and rooftop air samples but not from hospital potable water or community CTs. Hospital CT and air Lp-1 isolates matched all five patient isolates by monoclonal antibody, arbitrarily primed polymerase chain reaction, and pulsed-field gel electrophoresis subtyping. Strategies to prevent LD must include minimizing transmission from CTs.

Pathogenesis of Legionnaires>> disease is strictly related to the ability of the legionellae to infect phagocytic cells, yet surface markers of virulence in Legionella isolates are currently unknown. Rabbit antibodies raised against purified flagella of Legionella pneumophila serogroup 1 recognized a total of 24 of 30 laboratory-maintained isolates of L. pneumophila serogroups 1-15 and 16 of 24 other Legionella species tested by rapid immunoblot and indirect immunofluorescence assay. All isolates possessing flagella detectable with these anti-flagella antibodies, regardless of species, were capable of infecting Hartmannella vermiformis. Isolates lacking immunologic cross-reactivity were shown to lack purifiable flagella. The majority of aflagellate isolates were not motile and failed to multiply intracellularly in co-culture with Hartmannella vermiformis. Some isolates characterized as aflagellate when harvested from BCYE agar were able to multiply in amoebae, and flagella were subsequently detectable by immunologic methods. These data suggest that lack of immunologic recognition of flagella in laboratory-maintained isolates of Legionella is due to their attenuation and a corresponding loss of expression of flagella. More importantly, the presence of flagella can serve as a positive predictive marker for strain virulence and is useful in determining the virulence status of Legionella isolates.

An outbreak of community-acquired Legionnaires' disease (LD) occurred in Providence, R.I., in fall 1993. To find the outbreak source, exposures of 17 case patients were compared to those of 33 matched controls. Case patients were more likely than controls to have visited a section of downtown (area A) during the 2 weeks before illness (11 [65%] versus 9 [27%]; matched odds ratio, 6.5; P = 0.01). Water samples were cultured from 27 aerosol-producing devices within area A. Legionella pneumophila serogroup 1 isolates underwent monoclonal antibody (MAb) subtyping and arbitrarily primed PCR (AP-PCR). All four L. pneumophila serogroup 1 isolates available from case patients who visited area A had identical MAb and AP-PCR patterns. Among 14 environmental isolates, 5 had MAb patterns that matched the case patient isolates, but only 1 had a matching AP-PCR pattern. This investigation implicates a cooling tower in area A as the outbreak source and illustrates the usefulness of AP-PCR for identifying sources of LD outbreaks.

Twenty-two urine samples positive for Legionella pneumophila serogroup 1 antigen by EQUATE radioimmunoassay (RIA) (Binax, Portland, ME, USA) were stored at various temperatures and the RIA repeated at 1, 7, 30, 90, and 120 days to evaluate stability of the urinary antigens. The mean ratios of patient/negative control remained stable. Although there was a 10% decrease in the mean ratios after 1 month, changes were not significant. However, individual samples with ratios close to 3 may fall to < 3.

Two Legionella-like organisms were isolated from water samples obtained in Adelaide, Australia. One organisms was isolated from a drinking water distribution system, and the other was isolated from a cooling tower at a sewage treatment plant. Both strains required L-cysteine for growth and contained cellular branched-chain fatty acids and ubiquinones typical of the genus Legionella. These strains were serologically distinct from each other as determined by a slide agglutination test. STrain 2074-AUS-ET (T = type strain) was serologically distinct from all previously described Legionella species and serotypes. Strain 2055-AUS-E could not be differentiated biochemically or serologically from Legionella quinlivanii. Both strains were shown by DNA hybridization studies (Hydroxyapatite method) to be members of new Legionella species. Legionella waltersii sp. nov. is the name proposed for strain 2074-AUS-ET (= ATCC 51914T). L. waltersii was less than 10% related to other Legionella species. Strain 2055-AUS-E (= ATCC 51913) was informally named Legionella genomospecies 1, since it could not be phenotypically distinguished from L. quinlivanii. Legionella genomospecies 1 was closely related to L. quinlivanii strains (53 to 69% related with 4.5 to 6.5% divergence at 60 degrees C and 31 to 52% related at 75 degrees C).

The Legionella Urinary Antigen EIA kit (Binax, Portland, Maine) was compared with the EQUATE RIA Legionella Urinary Antigen kit (Binax) for its ability to detect the presence of urinary antigens to Legionella pneumophila serogroup 1. Urine specimens from patients without Legionnaires' disease (n = 33) were negative by both methods (specificity, 100%). Twenty (77%) of 26 urine specimens from patients with Legionnaires' disease positive by the radioimmunoassay kit were also positive by the enzyme immunoassay (EIA) kit. If the cutoff for a positive EIA result were lowered to a ration of > or = 2.5, 23 of 26 (88%) urine specimens would have been positive by EIA and the specificity would remain 100%. Use of the EIA kit is an acceptable method for detecting L. pneumophila serogroup 1 urinary antigens by laboratories that do not want to handle radioactive materials.

We examined the role of the flagella of Legionella pneumophila in the infection of amoebae and human monocyte-like cells. Insertional mutants were constructed with mini-Tn10. Ten mutants (F-) which did not react with polyclonal L. pneumophila antiflagellar antisera were identified. Ten randomly selected mutants (F+) that did react with the polyclonal antiflagellar antiserum were also identified. The infectivity of these 20 mutants in Hartmannella vermiformis and human U937 cells was characterized. Seven of the 10 F- mutants were attenuated in their ability to multiply in the amoebae during the first 3 days of coincubation and failed to multiply in U937 cells. Three of the 10 F- mutants multiplied as well as the wild-type parent strain did in amoebae and to a limited degree in U937 cells. None of the 10 F+ mutants were attenuated in either the amoebae or U937 cells. While the flagellar structure is not essential for virulence, the ability of L. pneumophila to infect amoebae and human phagocytic cells appears to be linked to flagellar expression. We believe that the attenuated F- mutants contain insertions in genes critical to both flagellum expression and the infection process.

Arbitrarily primed PCR (AP-PCR) and pulsed-field gel electrophoresis (PFGE) subtyping were applied to clinical and environmental isolates from seven unrelated outbreaks of Legionnaires' disease. The patterns observed with each method matched patient isolates and the epidemiologically linked source of disease for each of the seven outbreaks. PFGE allowed more discrimination among various isolates, although AP-PCR usually gave comparable results. With both methods, certain patterns appeared to predominate in the comparison of the seven outbreaks. Of five clinical isolates not associated with the outbreaks, three gave profiles distinct from those observed in the outbreaks by both methods. This suggests that there are at least two predominant subtypes of Legionella pneumophila serogroup 1 associated with outbreaks. Investigations of outbreaks of legionellosis should employ either PFGE or AP-PCR in addition to monoclonal antibody analysis.

We report two cases of pneumonia caused by Legionella cincinnatiensis, a species previously identified as a pathogen in only one other instance. Both infections occurred in renal transplant recipients who were receiving only moderate doses of immunosuppressive drugs several years after transplantation; both patients had no recent episodes of rejection. Their clinical courses varied from mild symptoms to multisystem organ failure and death. Species identification by direct fluorescent antibody testing was misleading; initial results revealed infection due to Legionella longbeachae for one patient and infection due to Legionella dumoffii for the other patient. Slide agglutination testing eventually identified both isolates as L. cincinnatiensis. Infection with Legionella species, including L. cincinnatiensis, should be considered not only in the first months after transplantation but also later in the posttransplantation period as either a nosocomial or community-acquired infection.

Arbitrarily primed polymerase chain reaction (AP-PCR) was used to characterize Legionella pneumophila serogroup 1. Cells from a single colony could be subtyped by AP-PCR within a few hours. The discrimination between strains of L. pneumophila serogroup 1 by AP-PCR was equivalent to that by monoclonal antibody analysis and ribotyping. Four strains representing the monoclonal antibody pattern most frequently associated with outbreaks all yielded unique amplicon patterns by AP-PCR.

Fourteen Legionella-like strains isolated from aquatic sources have been characterized serologically, biochemically, and in terms of DNA relatedness. The strains grew on buffered charcoal-yeast extract agar but not on blood agar and displayed phenotypic characteristics typical of the family Legionellaceae, including a requirement for cysteine, cellular fatty acid compositions in which branched-chain acids predominate, and the possession of isoprenoid quinones of the ubiquinone series with more than 10 isoprene units in their side chains. All were nonfermentative, lacked urease, were incapable of nitrate reduction, and reacted positively with a DNA probe specific for the Legionellaceae. DNA hybridization studies in which the hydroxyapatite method was used demonstrated that the strains represented five new species of the genus Legionella. Nine of the strains were more than 90% interrelated, and the name Legionella londiniensis sp. nov. is proposed for this group. Two strains formed a second hybridization group, for which the name Legionella nautarum sp. nov. is proposed, while the three remaining species, Legionella geestiana sp. nov., Legionella quateirensis sp. nov., and Legionella worsleiensis sp. nov., are each represented by a single strain. The levels of relatedness of the new species to each other are 23% or less, and the levels of relatedness to other members of the genus ranged from 0 to 36%. L. geestiana, L. nautarum, and L. londiniensis are serologically unrelated to all other known Legionella species. L. worsleiensis cannot be separated from Legionella pneumophila serogroup 4 by serological methods and is also serologically indistinguishable from L. quateirensis; distinctions may be made on the basis of fatty acid composition and biochemical reactions.

A Legionella-like organism, strain 1677-MI-H, was isolated from the bronchoscopy washings of a patient with pneumonia who had a 2-year history of progressive, chronic lymphocytic leukemia. The growth characteristics, cellular fatty acids, and ubiquinone content of the isolate were consistent with those for Legionella spp. The isolate was serologically distinct in the slide agglutination test with absorbed antisera. DNA hybridization studies showed that strain 1677-MI-H (ATCC 49751) represents a new Legionella species which is named Legionella lansingensis.

A Legionella-like organism (strain 214T [T = type strain]) was isolated from a cooling tower in Stratford-upon-Avon, England. This strain required L-cysteine and contained cellular branched-chain fatty acids that are typical of the genus Legionella. Strain 214T produced pink colonies on buffered charcoal-yeast extract agar. Ubiquinone Q-12 was the major quinone. Strain 214T was serologically distinct from other legionellae as determined by a slide agglutination test. The results of DNA hybridization studies showed that strain 214T (= ATCC 49655T) is a member of a new Legionella species, Legionella shakespearei.

From 10 October through 13 November 1989, 33 patients were hospitalized with legionnaires' disease in Bogalusa, Louisiana. A case-control study revealed case-patients were more likely than controls to have shopped at grocery store A (93% vs. 52%; odds ratio [OR], 11.6; 95% confidence interval [CI], 2.3-78.7) in the 10 days before illness. Among those who shopped at grocery store A, case-patients were more likely to shop for greater than 30 min (OR, 18.0; CI, 2.0-407.8) and to buy produce items located close to an ultrasonic mist machine (OR, 7.4; CI, 1.3-56.2). Employees of grocery store A were more likely than employees of other grocery stores in Bogalusa to have antibody titers of greater than or equal to 1:128 to Legionella pneumophila serogroup 1 (Lp-1; relative risk, 2.9; CI, 1.3-6.8). Lp-1 was isolated from water in the reservoir of the mist machine. The monoclonal antibody subtype of the isolate was identical to organisms identified in two patients. Viable Lp-1 was isolated from mist produced by the machine. Aerosols from a grocery store mist machine were the source of this outbreak.

A Legionella-like organism (strain 1762-AUS-E) was isolated from a cooling tower of an air-conditioning system in Adelaide, South Australia, Australia. The isolate was presumptively identified as a Legionella strain by its growth requirement for L-cysteine and its cellular branched-chain fatty acids. Strain 1762-AUS-E was serologically distinct in the slide agglutination test with absorbed antisera. DNA hybridization confirmed that it is a new Legionella species for which the name Legionella adelaidensis is proposed.