Direct immunofluorescent detection of Legionella pneumophila in respiratory specimens

Abstract

Respiratory secretions from patients with clinically suspected Legionnaires pneumonia were examined by direc immunofluorescent tests at the Medical Center Hospital of Vermont and at the Center for Disease Control. No fluorescent bacteria were found by either laboratory in eight specimens from eight patients who were seronegative. Twenty specimens were obtained from seven patients who had serologically confirmed Legionnaires disease. Four of the seven cases were identified at the Medical Center Hospital of Vermont, and six of the seven were identified at the Center for Disease Control. Of 20 specimens, 8 were positive at the Center for Disease Control (six or more bacilli per slide), and 7 specimens were suspicious (one to five bacilli per slide); at the Medical Center Hospital of Vermont, 4 of 20 specimens were positive, and 2 were suspicious. The inclusion of a rhodamine-conjugated counterstain at the Center for Disease Control facilitated the examination and may have improved the sensitivity. Smears from transtracheal aspirates, bronchoscopic aspirates, transcutaneous lung aspirates, pleural fluids, and tracheal aspirate-expectorated sputum produced positive results. Several specimens contained fluorescing bacilli when stained for serogroup 2 as well as serogroup 1, perhaps reflecting the presence of cross-reacting antigens in vivo.

Diagnosis of pneumonitis in immunocompromised patients by open lung biopsy

“…It may now be possible to make the diagnosis of Legionella pneumonia in many instances without resorting to the invasive methods. [12][13] The most notable difference between transplant and oncologic patients was the frequency of bacterial disease between the two groups. Among transplant recipients ' Over 70% of these patients had leukemia or lymphoma, while only 7% were transplant recipients.…”

Cross-reactions between Legionella pneumophila (serogroup 1) and twenty-eight other bacterial species, including other members of the family Legionellaceae

“…Antigen no. 66 resembled in precipitin morphology, mobility, and staining density antigen no. 0.57 in the Joly and Kenny Legionella XIE study (38).…”

“…1 was previously shown by us to be a very heatstable antigen on the surface of heat-killed L. pneumophila cells. Therefore, it may participate in antigen-antibody reactions during microagglutination, indirect immunofluorescent, or direct fluorescent antibody tests for L. pneumophila and thus be responsible for the cross-reactions reported between members of the Legionellaceae or between L. pneumophila and other gram-negative bacteria by these methods (13,39,49,(65)(66)(67).…”

“…Several serological studies have described cross-reactions between serogroups (SGs) of Legionella pneumophila and between L. pneumophila and other bacteria, leading to speculations concerning SG-specific antigens, Legionella-common antigens and antigens common to Legionella spp. and other bacterial species (13,39,49,(65)(66)(67). SG-specific antigens have been demonstrated by five different groups of investigators, all using precipitation reactions, but each using different antigen extraction methods (11,16,38,56,58).…”

Rapid culture‐based detection of Legionella pneumophila using isothermal microcalorimetry with an improved evaluation method

“…Besides this, there are several other techniques known for the detection of L. pneumophila : for instance, urinary antigen tests (UAT) (Bibb et al , 1984; Samuel et al , 1988; Dominguez et al , 1996), indirect and direct fluorescent antibody (IDFA) staining (Winn et al , 1980; Makin and Hart, 1989; Alary and Joly, 1992), a high number of different qualitative and quantitative polymerase chain reaction (PCR) approaches (Starnbach et al , 1989; Bej et al , 1991; Catalan et al , 1994; Matsiotabernard et al , 1994; MatsiotaBernard et al , 1997; Ballard et al , 2000; van der Zee et al , 2002; Fiume et al , 2005; Boss et al , 2018) and a variety of biosensors like surface plasmon resonance (SPR) immunosensor, electrochemical as well as genosensors etc. (Oh et al , 2003; Li et al , 2012; Mobed et al , 2019).…”