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N Bornstein

Publications and source records attributed to N Bornstein.

At least 37 records · Page 2Linked to original sources
PubMed1992

Study of cross-reaction between Coxiella burnetii and Legionella pneumophila using indirect immunofluorescence assay and immunoblotting.

Patients with Q fever and legionellosis may present identical clinical symptom. Differentiation of these diseases is made by serology, mainly the indirect immunofluorescence assay (IFA). Using IFA the authors tested 154 Q fever positive sera from 55 patients with acute Q fever and 28 patients with chronic Q fever for Legionella pneumophila antibodies and 57 sera from 57 patients with legionellosis for Coxiella burnetii antibodies. Of the 211 sera tested, four sera from different patients had antibodies to both C. burnetii and L. pneumophila. Using cross-adsorption studies and protein immunoblotting, no cross-reaction between C. burnetii and L. pneumophila antibodies could be identified. The moderate antibody titers against L. pneumophila in two Q fever patients and vice versa for one legionellosis patient are consistent with the incidence of seroprevalence in healthy blood donors and were not due to cross-reactivity. One patient was identified with concurrent Q fever and legionellosis.

Antibodies, Bacterial↗
PubMed1991

Detection of flagella in 278 Legionella strains by latex reagent sensitized with antiflagellum immunoglobulins.

To determine whether all Legionella species show common flagellum antigen properties, we developed a reagent using latex beads sensitized with flagellin-specific immunoglobulins that could be used in a simple and rapid agglutination reaction to identify Legionella colonies. A total of 278 strains (68 Legionella reference strains and 210 patient and environmental isolates) were tested. The results were compared with those obtained by a direct immunofluorescence assay using an antiflagellum serum and by morphological observations by electron microscopy. The immunological methods based on the use of a flagellum-specific serum have confirmed the presence of a common flagellum antigen for all Legionella species described to date. Flagella were detected for all the legionellae studied except four species: L. oakridgensis, confirmed as a nonflagellate species; L. brunensis; L. cincinnatiensis; and L. longbeachae serogroup 1. However, we noted a remarkable variability in flagellum expression, of greater or lesser degree, according to the species and their origin. A combination of all three methods of flagellum detection revealed that 86.3% of Legionella strains studied were flagellate. The latex test identified 89.6% of these strains, 97.5% of L. pneumophila, and 100% of L. pneumophila serogroup 1.

Antigens, Bacterial↗
PubMed1990

Relationship between free amoeba and Legionella: studies in vitro and in vivo.

In 1980, Robowtham demonstrated that Legionella multiplies in free amoeba cytoplasm and hypothesized that the amoeba could act as a reservoir of virulent bacteria. In this paper we report various aspects of the relationship between amoeba and Legionella. A liquid medium co-culture method was applied to Acanthamoeba sp. and Legionella pneumophila serogroup 1. Within 4 days, Legionella growth increased by 2 log s CFU/ml. Using a direct immunofluorescence assay and electron microscopy, Legionella was shown to grow abundantly inside phagosomes, and bacteria and/or antigen were present on the cytoplasmic membrane of the amoeba. These aspects are very similar to those observed with Legionella-infected alveolar macrophages. The morphology and structure of Legionella cells were modified after 20 days of co-culture: - viable bacteria showed large fatty cytoplasmic inclusions, - gas liquid chromatography analysis demonstrated a decrease in the i16:0 fatty acid ratio. Cystic forms of amoeba were abundant but none contained viable Legionella. In an in-vivo study using a guinea-pig aerosol infection model, we compared the virulence of Legionella in co-culture with Legionella grown on charcoal dialysed yeast extract (CDYE) agar medium. The Legionella obtained by co-culture had an LD 50 (50% lethal dose) similar to that obtained for those grown on CDYE, showing that bacterial virulence is preserved in the cellular model.

Acanthamoeba↗
PubMed1990

Detection of hippurate hydrolysis by Legionella spp. by using a rapid high-performance liquid chromatography method.

A rapid high-performance liquid chromatography method was developed to determine hippurate hydrolysis by Legionella spp. Benzoic acid, an end product of enzymatic activity, was directly detected by high-performance liquid chromatography after 1 and 24 h of incubation in 1% sodium hippurate. Because of its sensitivity, this procedure offers more precise identification of some Legionella spp.

Chromatography, High Pressure Liquid↗
PubMed1990

Nosocomial infection with Legionella pneumophila serogroup 1 and 8 in a neonate.

A case of pneumonia related to 2 serogroups (1 and 8) of Legionella pneumophila (Lp) in a 10-day-old boy is described together with the epidemiological survey in the maternity ward which made it possible to establish its nosocomial origin. Rodshaped bacteria reacting with an Lp genus-specific monoclonal antibody and serogroup 1 and 8 polyclonal sera were detected in bronchoalveolar lavages (BAL) collected on day 13. Serogroups 1 and 8 were recovered from cultures of BAL collected on days 12 and 13. Fourfold or more antibody rises to serogroups 1, 5, 8 and 10 of Lp were observed in sequential serum specimens. Water samples collected from the tank and mixer of the maternity ward grew serogroups 1 and 8 of Lp. Serogroup 1 was detected in large amounts in water samples taken at several points of the hot water supply system and from the oxygen nebulizers and the feeding-bottle heater. Analysis of the Lp serogroup 1 strains isolated from the water by subgroup-specific monoclonal antibodies revealed the presence of 4 different subgroups, one of which was identical to the Lp 1 subgroup isolated from the neonate's BAL. This latter subgroup, reactive with McKinney monoclonal antibody Mab 2, has been described as highly virulent. No other case of legionellosis was recorded in the maternity ward.

Cross Infection↗
PubMed1989

Legionella gratiana sp. nov. isolated from French spa water.

During an epidemiologic survey, an unidentified strain of Legionella was isolated from water of a thermal spa in France. The strain (Lyon 8420412) had the cultural and biochemical characteristics typical of the genus Legionella. In direct immunofluorescence tests, the strain reacted weakly with fluorescein-conjugated antisera prepared against L. bozemanii serogroups 1 and 2, L. longbeachae serogroups 1 and 2 and L. anisa, and failed to react with sera prepared against 36 other species or serogroups. A fluorescein-conjugated antiserum prepared against strain Lyon 8420412 reacted strongly with the homologous strain and only weakly with the above-mentioned species. The cell-wall fatty acid profile, with a predominance of hexadecenoic (16:1) and hexadecanoic (16:0) acids, ubiquinone Q10 as the major quinone and a characteristic protein electrophoresis profile suggested that the isolate was different from other Legionella species. In DNA-DNA hybridization experiments, the strain was distinct from all named Legionella species, and from all unnamed species currently under study at the Centers for Disease Control. The name Legionella gratiana is proposed for the new species (type strain Lyon 8420412; CDC 1242). A serologic survey of antibodies reacting against L. gratiana indicated that personnel or patients at the spa therapy centre where the organism was isolated had higher antibody titres than a control population.

Antibodies↗
PubMed1989

Exposure to Legionellaceae at a hot spring spa: a prospective clinical and serological study.

Following the occurrence of five cases of Legionnaires' disease among patients and therapists at a French hot spring spa, a series of cleansing procedures and an epidemiological study were undertaken. During a 3-month period, the spring water was repeatedly sampled. Serum samples were taken from 689 randomly selected patients, 230 therapists, 134 administrative staff and a control group of 904 blood donors. Legionellaceae were present in the spring water at concentrations of 10(3)-10(5) colony forming units/l. Fifteen different species or serogroups were isolated with Legionella pneumophila serogroups 3 and 1 predominating. No clinical cases of Legionnaires disease were observed during the study. However, 11% of the therapists and 5% of the patients either had a high titre of antibody (greater than or equal to 256) to at least one species or serogroup or seroconverted during the study. Mean antibody titres in the three study groups were significantly higher than those in the blood donors against 11 of the 32 legionella antigens tested. Nine of these 11 antigens corresponded to species or serogroups isolated from the spring water. The highest mean antibody titres in all three study groups were against L. pneumophila serogroup 3, the most common legionella in the spring water. These findings have important implications for the maintenance of adequate standards of hygiene, bacteriological sampling and clinical surveillance in this and similar establishments.

Adult↗
PubMed1989

Pleural infection caused by Legionella anisa.

The first case of infection caused by Legionella anisa with isolation of the organism is reported here. The presence of L. anisa in the water supply of the hospital and the isolation of this species in the pleural fluid of a patient suffering from nosocomial pleurisy confirm the potential pathogenicity of this Legionella species.

Adult↗
PubMed1988

An electron microscopy study of Legionella pneumophila after in vitro and in vivo culture.

The ultrastructure of Legionella pneumophila serogroup 1 (Philadelphia Strain) was studied by Scanning Transmission Electron Microscopy (STEM) following in vitro and in vivo culture. The results obtained were identical for all the samples tested; the structure belonged to the prokaryotic type, with features consistent with the known structure of Gram-negative rods. A characteristic feature is the loose undulated outer membrane, a peptidoglycan layer which was difficult to visualize and was better seen in lysed bacteria. The outermost layer was stained by ruthenium red for polysaccharides. In guinea-pig lung tissue and in chick embryo yolk sac membranes, the bacteria were more often intracellular in intracytoplasmic ribosome-studded vacuoles.

Animals↗
PubMed1988

Comparative efficacy of five antibiotics on experimental airborne legionellosis in guinea-pigs.

The efficacy of preventive and curative treatment of experimental airborne legionellosis in guinea-pigs was studied for erythromycin, rifampicin, minocycline, doxycycline and pefloxacin. The aerosol was produced from a strain of Legionella pneumophila serogroup 1 and dispersed in a chamber maintained below atmospheric pressure. Guinea-pigs were exposed for 30 min to 1 or 10 LD50 (10(3) or 10(4) viable inhaled organisms). Treatment was preventive or curative. Antibiotic concentrations in lungs and serum were evaluated during treatment. The action of the antibiotics on guinea-pigs infected by 1 LD50 resulted in 100% survival. For the 10 LD50 infection, pefloxacin, minocycline and erythromycin were more active (with 87.5% survivors) than doxycycline (75%) and rifampicin (62.5%). Preventive treatment with pefloxacin or doxycycline gave 100% protection, compared with 87.5% for rifampicin, 50% for erythromycin and 37.5% for minocycline. In this study, treatment of experimental legionellosis was improved, compared with previous publications, by early administration of antibiotics and increased dosage and duration.

Animals↗
PubMed1988

Efficacy of spiramycin on experimental airborne legionellosis in guinea pigs.

The effect of preventive and curative spiramycin therapy was studied in guinea pigs infected by aerosol with the experimental model previously tested. The infectious aerosol was obtained from a virulent strain of Legionella pneumophila (Philadelphia ATCC 33 152). Male guinea pigs (Dunkin-Hartley) weighing 250-300 g were exposed for 30 min to an aerosol of 1 or 10 LD50 (10(3) or 10(4) viable inhaled organisms). Spiramycin was administered intraperitoneally (150 mg/kg/day) 18 h after infection for five days for curative therapy; for preventive therapy it was administered on the day before and on the day of aerosol administration (10 LD50). The animals were observed during seven days for weight and temperature and 28 days for survival; bacterial (lungs, spleen) and serological tests were performed. Spiramycin levels (lungs, serum) were evaluated during treatment by a microbiological method. The survival rate in the treated guinea pigs after inhalation of 1 LD50 was 100%. For the 10 LD50 aerosol, curative and preventive therapy gave a survival rate of 87.5%; these results are significant when compared with results of non-treated animals, P less than 0.05. Spiramycin merits further study in experimental and human legionellosis.

Animals↗
PubMed1988

[Identification of Legionella by gas phase chromatography of fatty acids and high performance liquid chromatography of ubiquinones].

The fatty acids and ubiquinones of 44 reference strains corresponding to species of Legionella and 3 strains of Legionella isolated in the environment have been evaluated. The analysis of fatty acids profiles allows a classification of 22 species into 4 groups depending on the predominance of some branched-chain fatty acids of linear fatty acids. As for ubiquinones our results for the 22 species corroborate the classification in 5 groups established by Moss in 1983 based on the study of 10 species of Legionella. The analysis of fatty acids composition combined with ubiquinones content has allowed us to identify the antigenically similar strains which cannot be differentiated by direct immunofluorescence on one hand (strain 1) and on the other a more precise approach to the identification, before DNA-ADN hybridization of strains of new species (strains 2).

Chromatography, Gas↗
PubMed1987

Prevalence of legionellosis among adults: a study of community-acquired pneumonia in France.

Over a 24-month period, 274 patients with community-acquired pneumonia were hospitalized in Departments of Medicine at hospitals in Bordeaux, Lyon, Marseille, and Toulouse. Etiology of the pneumonia was determined either by organism identification or by indirect immunofluorescence in only 139 cases (51%). The most frequently isolated etiological agents were Streptococcus pneumoniae (34 cases), Legionella pneumophila (29 cases) and Mycoplasma pneumoniae (24 cases). The majority of patients with legionellosis were male (79%), middle aged (mean age: 53 years), and living in urban areas (69%). Their clinical features were atypical and did not differ from those of other pneumonias. Four patients with legionellosis (13.8%) died. L. pneumophila was isolated directly in only three instances. The study confirms the high prevalence of legionellosis (20%) among pneumonias of identified etiology. The fact that these cases had an atypical clinical presentation and that isolation of the organism was difficult reinforce the need to apply the CDC criteria for the interpretation of positive serological titers.

Age Factors↗
PubMed1987

Bacteriological and serological diagnosis of community-acquired acute pneumonia, specially Legionnaire's disease. Multicentric prospective study of 274 hospitalized patients.

In 1982 and 1983 a prospective study was carried out involving 274 adult patients hospitalized with community-acquired acute pneumonia. The results of the bacteriological and serological diagnoses are presented here. Conventional and standardized bacteriological methods were used. All the serodiagnoses of LD were carried out with the 13 antigens produced by the "Centre National de Référence" (L. pneumophila 1, 2, 3, 4, 5, 6; L. micdadei; L. bozemanii, L. dumoffii, L. jordanis; L. gormanii; L. longbeachae 1 and 2). Standardized criteria were used for the interpretation of results. Conventional methods were used for the other serodiagnoses. Because the laboratory results had been interpreted very rigorously, an etiological diagnosis was established only in 51% of pneumonia cases. Other reasons, such as the frequent prescription of antibiotics prior to hospitalization, may explain why no aetiology could be determined in 49% of cases. The microbial agents responsible were: S. pneumoniae, Legionella and M. pneumoniae in 62% of cases; H. influenzae, K. pneumoniae, Chlamydia and S. aureus in 21.6%; and viruses in 8.6%. 29 (10%) of the 274 pneumonia cases were caused by Legionella, being second to S. pneumoniae. The preponderance of L. pneumophila was striking (22 cases), 3 Legionella strains were isolated (L. pneumophila serogroup 1:2 strains, serogroup 6:1 strain). Three associated or successive infections were observed (influenza, Leptospirosis, Coxiella infection). As regards the other bacteria, implication of the strain isolated was based on its multiple occurrence in several samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1987

Effect of culture medium on morphology and virulence of Legionella pneumophila serogroup 1.

In a preliminary study, the preparation of a modified charcoal yeast extract by predialysis of yeast extract (CDYE) allowed us to obtain short non filamentous forms of Legionella pneumophila ser 1 (Philadelphia) found to be more virulent in the chick embryo than the long forms grown on conventional media. We confirmed these findings in guinea pigs inoculated by either intraperitoneal injection or aerosol inhalation. LD50s were calculated using the method of Reed and Muench. Survival curves were established using Liddell's method. If for chick embryo the most virulent organisms were those derived from yolk sac culture, organisms grown on CDYE agar were more virulent than those grown on the other media. There was a significant positive correlation between the mean length of the bacilli and the log 10 of the LD50 (r = 0.96; 0.02 less than p less than 0.05). For guinea pigs by either intraperitoneal injection or inhalation we confirmed that the bacteria cultured on CDYE were more virulent than those grown on other solid media. Thus for the guinea pig inoculated intraperitoneally, the LD50s of the CDYE and BCYE cultures were 1.4 X 10(7) and greater than 3 X 10(9) CFU, respectively. The mortality of guinea pigs inoculated by aerosol with CDYE cultures was significantly higher than that of guinea pigs infected with BCYE cultures using suspensions of 10(8) and 10(9) CFU/ml (p less than 0.01) and 10(10) CFU/ml (p less than 0.05).

Aerosols↗