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PubMed1981

Detection of cell-associated or soluble antigens of Legionella pneumophila serogroups 1 to 6, Legionella bozemanii, Legionella dumoffii, Legionella gormanii, and Legionella micdadei by staphylococcal coagglutination tests.

Current methods used for the detection of whole-cell isolates of Legionella or for the detection of Legionella soluble antigens are technically impractical for many clinical laboratories. The purpose of this study was to explore practical alternatives. The results showed that whole cell isolates of Legionella pneumophila serogroups 1 to 6, Legionella bozemanii, Legionella dumoffii, Legionella gormanii, and Legionella micdadei were identified specifically by a simple slide agglutination test or slide coagglutination test in which the reagent antisera are first bound to staphylococcal protein A. Soluble antigens were also identified specifically by the slide coagglutination test and by a sandwich immunofluorescence assay. The latter test may be useful in detecting antigen in body fluids of patients with legionellosis or in environmental samples.

Agglutination Tests↗

PubMed2001

Legionella drozanskii sp. nov., Legionella rowbothamii sp. nov. and Legionella fallonii sp. nov.: three unusual new Legionella species.

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.

Acanthamoeba↗

PubMed1991

Vaccination with the major secretory protein of Legionella induces humoral and cell-mediated immune responses and protective immunity across different serogroups of Legionella pneumophila and different species of Legionella.

In a previous study, we demonstrated that immunization of guinea pigs with the major secretory protein (MSP) of Legionella pneumophila, serogroup 1 induced humoral and cell-mediated immune responses to MSP and protective immunity against lethal aerosol challenge with this serogroup of L. pneumophila. Although serogroup 1 L. pneumophila cause most cases of Legionnaires' disease, other serogroups of L. pneumophila and species of Legionella cause many cases. In this study, we have examined if immunization with MSP induces humoral and cell-mediated immune responses and protective immunity across different serogroups of L. pneumophila and species of Legionella. By immunoblot analysis, MSP from L. pneumophila serogroup 1 (Lp1 MSP), L. pneumophila serogroup 6 (Lp6 MSP), and Legionella bozemanii (Lb MSP) shared common epitopes recognized by guinea pig anti-Lp1 MSP antiserum. These MSP molecules, however, were not identical as they had different apparent m.w. Immunization of guinea pigs with MSP induced strong cell-mediated immune responses across the different serogroups and species, as indicated by splenic lymphocyte proliferation and cutaneous delayed-type hypersensitivity in response to both homologous and heterologous MSP. Immunization with MSP induced strong protective immunity across two serogroups of L. pneumophila; overall, 9 survived aerosol challenge with L. pneumophila serogroup 1 compared to 0 of 12 (0%) sham-immunized control animals (p = 3 x 10(-4), Cochran-Mantel-Haenzel chi 2 statistic for pooled data). Immunization with MSP also induced protective immunity across species of Legionella but protection was species-specific. Whereas immunization with Lb MSP induced protective immunity against L. pneumophila, neither immunization with Lp1 MSP nor immunization with Lb MSP induced protective immunity against L. bozemanii, which produces MSP. Not surprisingly, immunization with MSP did not induce protective immunity against MSP-negative Legionella micdadei. In the case of both L. bozemanii and L. micdadei, immunization with a sublethal dose did confer protective immunity to aerosol challenge indicating that these species do contain immunoprotective components. This study demonstrates that immunization with MSP induces humoral and cell-mediated immune responses across different serogroups of L. pneumophila and species of Legionella, but that the capacity of MSP immunization to induce protective immunity is species-specific. Nevertheless, an MSP vaccine has the potential to induce protective immunity against the great majority of cases of Legionnaires' disease.

Aerosols↗

PubMed1998

A colony based confirmation assay for Legionella and Legionella pneumophila employing the EnviroAmp Legionella system and seroagglutination.

Modifications to the EnviroAmp Legionella detection system are described which permit the rapid analysis of bacterial colonies taken from Legionella selective media. Capillary PCR permitted twice the number of samples to be analysed with a single kit. When PCR was positive for Leg. pneumophila, this result was confirmed by seroagglutination. The reverse dot blot hybridization assay was only used where PCR indicated a Legionella sp. other than Leg. pneumophila, permitting further savings on detection system components. This technique and standard confirmation procedures were applied to 133 isolates arising from 63 water samples plated to Legionella isolation media. Results agreed except for two isolates which gave a positive result for Legionella spp. by PCR and hybridization but were negative using standard procedures. Raising the annealing/extension temperature of the PCR by 2 degrees C eliminated the false positive result with these two isolates but did not adversely effect the sensitivity of the assay, as determined by re-testing of 68 environmental isolates and testing of 69 new environmental isolates and 12 Legionella reference species. The modified technique provides a convenient and cost effective alternative to standard confirmation procedures.

Agglutination↗

PubMed2006

Evaluation of the Duopath Legionella lateral flow assay for identification of Legionella pneumophila and Legionella species culture isolates.

Duopath Legionella (Merck KGaA, Darmstadt, Germany) is a new immunochromatographic assay for the simultaneous identification of cultured L. pneumophila and Legionella species other than L. pneumophila. In tests of 89 L. pneumophila strains and 87 Legionella strains other than L. pneumophila representing 41 different species, Duopath and a widely used latex agglutination assay detected L. pneumophila with 100% and 98% accuracy, respectively, whereas the percentages differed significantly for other Legionella spp. (93% versus 37% [P < 0.001]). Since many countries' regulations require the identification of Legionella spp. in water and environmental samples, the use of Duopath Legionella to comply with those regulations could contribute to significantly fewer false-negative results.

Chromatography↗

PubMed1998

Comparison of the Binax Legionella urinary antigen enzyme immunoassay (EIA) with the Biotest Legionella Urin antigen EIA for detection of Legionella antigen in both concentrated and nonconcentrated urine samples.

We evaluated a newly commercial enzyme immunoassay (EIA) (Biotest Legionella Urin Antigen EIA; Biotest AG, Dreieich, Germany) for detection of antigens of all Legionella pneumophila serogroups with a relatively wide spectrum of cross-reactivity as well as antigens of other Legionella spp. by comparing its sensitivity and specificity with those of an EIA for detection of L. pneumophila serogroup 1 antigen (Legionella urinary antigen EIA; Binax, Portland, Maine). Both tests were performed with both concentrated and nonconcentrated urine samples. We also evaluated the capabilities of both EIAs to detect extracted soluble antigens of American Type Culture Collection (ATCC) Legionella strains (L. pneumophila serogroups 1 to 14, L. bozemanii, and L. longbeachae). The sensitivity of the Biotest EIA was 66.66% in nonconcentrated urine and 86.66% in concentrated urine. The sensitivity of the Binax EIA was 63.76% and 88.88% in nonconcentrated and concentrated urine, respectively. The specificity was 100% in nonconcentrated and concentrated urine for both assays. The Binax EIA and Biotest EIA detected extracted soluble antigens of L. pneumophila serogroups 1 to 14 and L. bozemanii ATCC strains. The cross-reactions observed with the Binax EIA were probably due to common epitopes directly related to lipopolysaccharide. Further studies are required to determine the usefulness of the Binax EIA for detection of urinary antigens from Legionella species and serogroups other than L. pneumophila serogroup 1. The Biotest EIA proved to be as rapid, sensitive, and specific as the Binax EIA for the diagnosis of legionellosis. Concentration of antigen present in urine increased the sensitivities of both techniques with no reduction in specificity.

Adult↗

PubMed1987

Legionella micdadei and Legionella dumoffii monoclonal antibodies for laboratory diagnosis of Legionella infections.

Two different monoclonal antibodies directed against Legionella micdadei and L. dumoffii (Genetic Systems Corp., Seattle, Wash.) were evaluated for their specificity and ability to detect L. micdadei and L. dumoffii in human and animal clinical samples and bacterial isolates in an indirect immunofluorescence assay. All three frozen sputum samples and all three Formalin-fixed sputum and liver samples from patients with culture-documented L. micdadei pneumonia were positive when tested with the L. micdadei monoclonal antibody. A Formalin-preserved lung sample from a patient with culture-documented L. dumoffii pneumonia was positive with its homologous monoclonal antibody. No cross-staining reactions were found with either monoclonal antibody on any of 25 human sputum samples tested from patients without Legionella infections. A total of 66 Legionella strains and 56 non-Legionella strains including 22 Pseudomonas strains and 34 other bacterial strains were studied. No cross-staining reactions were found except in Staphylococcus aureus Cowan 1 ATCC 12598. The lower limit of detection in seeded sputum samples was about 7 X 10(4) cells per ml for both monoclonal antibodies. Lung and tracheal lavage specimens from L. micdadei- or L. dumoffii-infected guinea pigs showed specific staining only with their respective monoclonal antibodies. The monoclonal antibodies stained homologous bacteria slightly less intensely than did the polyclonal antisera, but the signal-to-noise ratio was considerably higher for the monoclonal antibodies. No differences in sensitivity of staining of clinical specimens or bacterial isolates were noted between the monoclonal antibodies and the polyclonal reagents for L. micdadei and L. dumoffii (Centers for Disease Control, Atlanta, Ga., and BioDx, Denville, N.J. These monoclonal antibodies ae sensitive and specific, making them good candidates for laboratory diagnostic purposes.

Animals↗

PubMed2001

Detection of Legionella pneumophila antigen in urine samples by the BinaxNOW immunochromatographic assay and comparison with both Binax Legionella Urinary Enzyme Immunoassay (EIA) and Biotest Legionella Urin Antigen EIA.

The new BinaxNOW Immunochromatographic (ICT) Assay for the detection of Legionella pneumophila antigens was used to test 535 urine specimens from patients with and without Legionnaires' disease. The specificity, calculated by testing 112 samples from patients with pneumonia of aetiologies other than Legionella infection, and 167 urine specimens from urinary tract infections, was found to be 97.1% if the manufacturer's guidelines were followed. However, it was determined that the 'false positive' results characterised by very weak bands could be discounted by re-examination of the results at 60 min, yielding a specificity of 100%. With this minor modification of the procedure applied to examination of urine samples from 117 patients with legionellosis confirmed by isolation of L. pneumophila and 70 patients who had seroconverted to L. pneumophila serogroup 1, sensitivity was calculated to be 79.7%. In comparison, the sensitivities of the Binax Urinary Antigen Enzyme Immunoassay (EIA) and Biotest Urin Antigen EIA were estimated to be 79.1 and 83.4%, respectively. Eleven cases (5.9%) were positive by BinaxNOW assay but negative by Binax or Biotest EIA, or both. The sensitivities of all assays increased to c. 94% if only diagnosis of cases confirmed by isolation of serogroup 1 L. pneumophila was considered, although the sensitivity for infections caused by L. pneumophila serogroup 1 monoclonal antibody (MAb) subgroup Bellingham was significantly lower than for other MAb subgroups. The Biotest EIA recognised 10 (45%) of the 22 cases not caused by L. pneumophila serogroup 1, whereas the two Binax kits detected only three each. The ICT assay BinaxNOW can be recommended as a rapid specific test for the diagnosis of Legionnaires' diseases caused by L. pneumophila serogroup 1, although very weak bands should be interpreted cautiously.

Antibodies, Monoclonal↗

PubMed1994

Chemical characterization of lipopolysaccharides from Legionella feeleii, Legionella hackeliae and Legionella jordanis.

Lipopolysaccharides (LPS) from Legionella feeleii serogroup 1, L. hackeliae serogroup 1 and L. jordanis were subjected to chemical analysis. All three LPS contained D-mannose, D-glucose, D-glucosamine, L-glycero-D-manno-heptose, 2-keto-3-deoxyoctonic acid and glycerol. In addition the LPS of L. feeleii was characterized by L-quinovose (tentatively identified) and L-fucosamine, L. hackeliae LPS by D-quinovosamine, D-galactosamine and D-galacturonic acid, and L. jordanis LPS by D-quinovosamine. Phosphorylated sugars were detected in all three LPS. The backbone sugar of the lipid A part was in each case 2,3-diamino-2,3-dideoxy-D-glucose substituted with a complex pattern of fatty acid, including 20-22 different amide-linked (non-branched and methyl-branched) 3-hydroxy fatty acids of chain-length ranging from 12 to 23 carbon atoms. The fatty acid patterns included also ester-linked nonhydroxylated entities and the uncommon 27-oxo-octacosanoic acid and 29-oxotriacontanoic acid. The LPS of L. hackeliae and L. jordanis also contained heptacosane-1,27-dioic and nonacosane-1,29-dioic acid, and their 2-hydroxy analogues were characteristic of L. jordanis LPS. SDS-PAGE patterns of the three LPS were distinctly different. Both L. feeleii and L. jordanis produced smooth-form LPS with characteristic ladder patterns, whereas L. hackeliae LPS were of more rough-type character.

Carbohydrates↗

PubMed1994

Composition of 2,3-dihydroxy fatty acid-containing lipopolysaccharides from Legionella israelensis, Legionella maceachernii and Legionella micdadei.

Lipopolysaccharides (LPS) from Legionella israelensis, L. maceachernii and L. micdadei were analysed for chemical composition. The main sugar of the lipid A fractions was in each case 2,3-diamino-2,3-dideoxy-D-glucose. Lipid A of L. israelensis also contained a substantial amount of D-glucosamine. In each lipid A fraction a complex fatty acid pattern was detected. This comprised at least 19 different 3-hydroxy fatty acids (amide-linked), three 2,3-dihydroxy fatty acids (amide-linked), non-hydroxy fatty acids (ester-linked) as well as long-chain (omega-1)-oxo, (omega-1)-hydroxy and (1,omega)-dioic fatty acids (ester-linked). In addition, L. maceachernii and L. micdadei contained alpha-hydroxylated long-chain (omega-1)-oxo and (1,omega)-dioic fatty acids. The polysaccharide parts of L. maceachernii and L. micdadei LPS were similar and contained mainly L-rhamnose, L-fucose, D-mannose, D-glucose, L-fucosamine, D-glucosamine, 2-keto-3-deoxy-octonic acid (Kdo) as well as the rare octose yersiniose A. The corresponding composition of L. israelensis LPS was simpler and consisted mainly of L-rhamnose and 3-amino-3,6-dideoxy-D-mannose. LPS of L. israelensis and L. micdadei contained, in addition, 2-keto-octonic acid linked to Kdo. Phosphorylated sugar constituents were detected in all three LPS, whereas ethanolamine was found only in LPS from L. maceachernii. The SDS-PAGE band pattern of L. micdadei differed from the two others in a higher proportion of the low molecular mass constituents.

Carbohydrate Conformation↗

PubMed2006

Evaluation of two new immunochromatographic assays (Rapid U Legionella antigen test and SD Bioline Legionella antigen test) for detection of Legionella pneumophila serogroup 1 antigen in urine.

We evaluated two new immunochromatographic assays for their abilities to detect Legionella pneumophila serogroup 1 antigen in urine. The results were compared with those obtained by the Binax NOW urinary antigen test. The sensitivities and specificities were estimated to be 71.2% and 96.6%, respectively, for the Rapid U test; 31.5% and 98.9%, respectively, for the SD Bioline test; and 91.8% and 100%, respectively, for the Binax NOW test.

Antigens, Bacterial↗

PubMed2007

Legionella impletisoli sp. nov. and Legionella yabuuchiae sp. nov., isolated from soils contaminated with industrial wastes in Japan.

In this study, we tried to isolate legionellae from nine Legionella DNA-positive soil samples collected from four different sites contaminated with industrial wastes in Japan. Using culture methods with or without Acanthamoeba culbertsoni, a total of 22 isolates of legionellae were obtained from five of the nine samples. Identification of species and/or serogroups (SGs), performed by DNA-DNA hybridization and agglutination tests, revealed that the 22 isolates consisted of ten isolates of Legionella pneumophila including five SGs, five Legionella feeleii, and one each of Legionella dumoffii, Legionella longbeachae, and Legionella jamestownensis. The species of the remaining four isolates (strains OA1-1, -2, -3, and -4) could not be determined, suggesting that these isolates may belong to new species. The 16S rDNA sequences (1476-1488bp) of the isolates had similarities of less than 95.0% compared to other Legionella species. A phylogenetic tree created by analysis of the 16S rRNA (1270bp) genes demonstrated that the isolates formed distinct clusters within the genus Legionella. Quantitative DNA-DNA hybridization tests on the OA1 strains indicated that OA1-1 should be categorized as a new taxon, whereas OA1-2, -3, and -4 were also genetically independent in another taxon. Based on the evaluated phenotypic and phylogenetic characteristics, it is proposed that one of these isolates from the soils, OA1-1, be classified as a novel species, Legionella impletisoli sp. nov.; the type strain is strain OA1-1(T) (=JCM 13919(T)=DSMZ 18493(T)). The remaining three isolates belong to another novel Legionella species, Legionella yabuuchiae sp. nov.; the type strain is strain OA1-2(T) (=JCM 14148(T)=DSMZ 18492(T)). This is the first report on the isolation of legionellae from soils contaminated with industrial wastes.

Acanthamoeba↗

PubMed1997

Development of a new seminested PCR method for detection of Legionella species and its application to surveillance of legionellae in hospital cooling tower water.

The presence of PCR inhibitors in water samples is well known and contributes to the fact that a practical PCR assay has not been developed for legionella surveillance. In this study, we devised a new seminested PCR assay for detection of Legionella spp. in water samples as a means of overriding the PCR inhibitors without loss of sensitivity. The seminested PCR assay utilized primers to amplify the 16S rRNA gene (LEG primers) of 39 Legionella spp. The assay was specific to legionellae, and the sensitivity was 1 fg of extracted Legionella DNA in laboratory examination. To evaluate the feasibility and sensitivity of the PCR assay in identifying the presence of legionellae, it was used to survey Legionella contamination in the water of 49 cooling towers of 32 hospitals. A commercially available EnviroAmp Legionella kit and a culture method were also used in the survey for comparison with the seminested PCR assay. The detection rates of legionellae in the samples were 91.8% (45 of 49) by the PCR assay and 79.5% (39 of 49) by the culture method. The EnviroAmp kit revealed that 30.6% of the water samples (15 of 49) contained inhibitors of the PCR amplification. However, the seminested PCR assay could produce the Legionella-specific DNA bands in 14 of the 15 samples. Although 8 of the 14 samples were positive in the first-step PCR, 6 of the 14 samples became positive in the second-step PCR. These results suggest that the effect of PCR inhibitors in samples, if any, can be reduced because of the dilution of the sample in the second-step PCR and that sensitivity of detection can be increased by the second-step PCR. Thus, the seminested PCR assay with LEG primers to amplify the 16S rRNA gene of 39 Legionella spp. was a practical and sensitive method to detect Legionella spp. in water samples.

Air Conditioning↗

PubMed2005

Isolation of pathogenic Legionella species and legionella-laden amoebae in dental unit waterlines.

Legionella released into the air during treatment are a potential source of infection. Water stagnation in dental unit waterlines (DUWLs) creates biofilms and promotes the proliferation of these micro-organisms. This study investigated the presence of amoeba infected with legionella, L. pneumophila and other pathogenic Legionella species in a dental teaching hospital. Water samples were collected in the morning and afternoon from 99 dental units and 16 taps connected to the municipal water supply. Samples were plated on selective media and tested for legionella using the direct immunofluorescent antibody technique and the latex agglutination test. Legionella were found in 33% of the DUWLs and in 47% of the mains taps supplying these units. Legionella-laden amoebae occurred in one mains tap sample and in 20% of DUWLs in a clinic of the teaching hospital. L. micdadei was the predominant species isolated from this clinic. L. pneumophila serogroups 2-14 predominated in the mains water, whereas L. pneumophila serogroup 1 was found in approximately half of the contaminated DUWLs and mains taps irrespective of the time of sampling. Pathogenic Legionella species seeded by municipal water into DUWLs is a potential source of legionella infection for both dental personnel and patients during prolonged dental treatment. This problem is compounded by the presence of legionella-laden amoebae which may contain levels of organism well within the infective dose. The interaction of legionella with amoebae is an important ecological factor that may significantly increase the risk of legionellosis, and thus should be given further consideration in the refinement of risk assessment models.

Amoeba↗

PubMed2006

Development of an improved PCR-ICT hybrid assay for direct detection of Legionellae and Legionella pneumophila from cooling tower water specimens.

A novelly improved polymerase chian reaction and immunochromatography test (PCR-ICT) hybrid assay comprising traditional multiplex-nested PCR and ICT, (a lateral-flow device) was developed for direct detection of Legionella bacteria from environmental cooling tower samples. The partial 16S rDNA (specific for Legionella spp.) and dnaJ (specific for Legionella pneumophila) genes from Legionella chromosome were first specifically amplified by multiplex-nested PCR, respectively, followed by detection using ICT strip. Reading of results was based on presence or absence of the two test lines on the strips. Presence of test line 1 indicated existence of Legionella spp. specific 16S rDNA and identified Legionella spp. Presence of test line 2 further indicated existence of dnaJ and thus specifically identified L. pneumophila. In contrast, for non-Legionellae bacteria no test line formation was observed. Results of direct detection of Legionella bacteria and L. pneumophila from water tower specimens by this assay showed 100% sensitivity, and 96.6% and 100% specificity, respectively compared with traditional culture, biochemical and serological identification methods. The PCR-ICT hybrid assay does not require sophisticated equipment and was proved to be practically useful in rapid and direct Legionellae detection from environmental water samples.

Base Sequence↗

PubMed2003

Prevalence of legionella waterline contamination and Legionella pneumophila antibodies in general dental practitioners in London and rural Northern Ireland.

OBJECTIVES: To determine the prevalence of legionellae in dental unit waterlines (DUWL) in general dental practices in London and rural Northern Ireland and whether the organism occurs at a high enough frequency and magnitude in DUWL to represent a threat to dentists' health. MATERIALS AND METHOD: Two hundred and sixty six (166 London, 100 Northern Ireland) randomly selected dental surgeries were recruited. Standardised 250 ml water samples were taken from the DUWL and 1 litre samples from the surgery cold water tap to measure the prevalence of legionellae. The dentists provided a blood sample for legionella serology. RESULTS: The prevalence of legionellae was very low (0.37%). Legionellae were not isolated from DUWL or surgery basin taps in Northern Ireland. Legionella spp were isolated from the DUWL and surgery basin of one practice in London and from the cold water supply of a further three practices. The prevalence of Legionella pneumophila antibodies was less than that seen in a comparable group of London blood donors. CONCLUSION: The risk to dentists' health from potential exposure to legionellae in this cohort of dentists was very low and this was confirmed by the very low seroprevalence and antibody titres to legionella detected in the dentists.

Antibodies, Bacterial↗

PubMed1995

Detection of Legionella species in reclaimed water and air with the EnviroAmp Legionella PCR kit and direct fluorescent antibody staining.

Reclaimed water is an important resource for areas with inadequate water supplies. However, there have been few studies on the variety of microorganisms found in this type of water, since typically reclaimed water is examined only for the presence of coliform bacteria. Many microorganisms, including the legionellae, are known to be more resistant to chlorine than are coliform bacteria. Previously, we detected > 10(3) Legionella cells per ml in primary and secondary sewage effluents and observed no significant reduction in population numbers throughout the treatment process. In this study, we detected Legionella spp. in chlorinated effluent by using an EnviroAmp Legionella PCR kit and direct fluorescent antibody (DFA) staining. However, we were not able to isolate Legionella spp. from either natural or seeded reclaimed water samples. This suggests that the Legionella spp. detected by the PCR and DFA methods may be injured or viable but nonculturable after exposure to the high residual chlorine levels typically found in this type of water source. The numbers of coliform bacteria were low (< 2 cells per 100 ml) in most reclaimed water samples and were not correlated with the presence or absence of Legionella spp. We also collected air samples from above a secondary aeration basin and analyzed them by using the PCR, DFA, and plate culture methods. Legionella spp. were detected in the air obtained from above the secondary basin with all three methods. We concluded that the PCR was superior to the culture and DFA methods for detecting Legionella spp. in environmental water samples.

Air Microbiology↗

PubMed1996

Legionella waltersii sp. nov. and an unnamed Legionella genomospecies isolated from water in Australia.

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).

Agglutination Tests↗