Sequence based typing and pre-absorption test in retrospective analysis of a pseudo-outbreak of Legionella infections differentiates true cases of legionellosis

Katarzyna Pancer 1, Karina Jahnz-Różyk 2, Aleksandra Kucharczyk 3, Włodzimierz Gut 1, Piotr Kucharczyk 2, Pernille L Elverdal 4, Bogumiła Litwińska 1
1 - National Institute of Public Health-National Institute of Hygiene, Warsaw, Poland
2 - Department of Immunology and Clinical Allergology, Military Institute of Medicine, Warsaw, Poland
3 - Department of Immunology and Clinical Allergology, Military Institute of Medicine, Warsaw, Poland
4 - Serum Production, SSI Diagnostica, Statens Serum Institute, Hillerod, Denmark
Ann Agric Environ Med
2012; 19 (3):
ICID: 1010965
Article type: Original article
 
 
The aim of this study was elimination of false positive results obtained by the Chlamylege kit. Two serological kits (IgM ELISA L.pneumophila sgs1-7; ImmuViewTM L.pneumophila sg1/sg3) and pre-absorption tests (with L.pneumophila sg1 and sg3 reference strains antigens) were used. 153 sera (79 patients) were examined. The high correlations were found between the results by both tests. Positive results by ELISA (sgs1-7) were found in 19/79 patients; by ImmuViewTM (sg1+sg3) in 16/63. In 8 patients, the dynamics of the IgM in pairs of sera was high (ratio ≥2). In 5/8 of those patients seroconversion was determined. Selected pre-absorbed sera (15 pairs) were tested simultaneously by the same tests. In 8/15 pairs of sera, the reduction of IgM levels in pre-absorbed sera was higher than 10. The reduction of IgM differed in sg1 and sg3 tests. The probability of infections due to L.pneumophila sg3 (7 patients) and L.pneumophila sg1 (5 patients) was based on the results of pre-absorption tests. The correlation between ELISA and ImmuViewTM tests of pre-absorbed sera was statistically significant (Po=0.0389). Moreover, genotyping of L.pneumophila (SBT) directly in the sera of selected 15 patients (high IgM reduction) was carried out. Completed 7 alleles profile (ST36) was determined in one patient. However, a second patient had the same profile of 5 alleles, and similar reactions in pre-absorption tests. At least 4 sources of infections were suggested on the base of genotyping and pre-absorption results.
Conclusions: Positive results obtained by molecular techniques (eg.PCR) in the diagnosis of Legionella infections should be supplemented by other tests for confirmation of legionellosis. The sequence based typing carried out directly in clinical specimens seems to be a promising method.
PMID 23020036 - click here to show this article in PubMed
  FULL TEXT STATS

Recommend this article to:

Name:
E-mail:
From:
Language:


Related articles in IndexCopernicus™
     legionellosis [10 related records]
     pseudo-outbreak [0 related records]
     false positive results [0 related records]
     Legionella serology [0 related records]
     pre-absorption test [0 related records]
     sequence base typing [0 related records]



 

Related articles

A Figas, M Wieczorek,
Detection of Polioviruses in Sewage Using ...
The work presented here demonstrates the utility of a two-step algorithm for environmental poliovirus surveillance based on: preselection of sewage samples tested for the presence of enteroviral genetic material-RT-PCR assay and detection of infectio...
ABSTRACT
Z Gut,
SELECTED APPLICATION OF ELECTRICAL CAPACITANCE TOM...
 The article describes experimental studies using electrical Capacitance tomography (eCt) in monitoring the combustion processes. the main goal of the study was to develop a new diagnostic method suitable for monitoring flame and the combustio...
ABSTRACT
E Więsik-Szewczyk, K Jahnz-Różyk,
Autoimmune connective tissue diseases and vaccinat...
The idea that infectious agents can induce autoimmune diseases in genetically susceptible subjects has been a matter of discussion for years. Moreover, increased incidence of autoimmune diseases and introduction of prophylactic vaccinations from earl...
ABSTRACT