Detection of Legionella spp. by a nested-PCR assay in air samples of a wastewater treatment plant and downwind distances in Isfahan


1 Department of Environmental Health Engineering and Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran

2 Department of Statistics and Epidemiology, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran


Background: Wastewater contains a variety of pathogens and bio -aerosols generated during the wastewater treatment process, which could be a potential health risk for exposed individuals. This study was carried out to detect Legionella spp. in the bio -aerosols generated from different processes of a wastewater treatment plant (WWTP) in Isfahan, Iran, and the downwind distances.
Materials and Methods: A total of 54 air samples were collected and analyzed for the presence of Legionella spp. by a nested- polymerase chain reaction (PCR) assay. A liquid impingement biosampler was used to capture bio -aerosols. The weather conditions were also recorded.
Results: Legionella were detected in 6% of the samples, including air samples above the aeration tank (1/9), belt filter press (1/9), and 250 m downwind (1/9).
Conclusion: The result of this study revealed the presence of Legionella spp. in air samples of a WWTP and downwind distance, which consequently represent a potential health risk to the exposed individuals.


Catalan V, Garcia F, Moreno C, Vila MJ, Apraiz D. Detection of Legionella pneumophila in wastewater by nested polymerase chain reaction. ResMicrobiol 1997;148:71-8.  Back to cited text no. 1
Palmer CJ, Bonilla GF, Roll B, Paszko-Kolva C, Sangermano LR, Fujioka RS. Detection of Legionella species in reclaimed water and air with the EnviroAmp Legionella PCR kit and direct fluorescent antibody staining. Appl Environ Microbiol 1995;61:407-12.  Back to cited text no. 2
Palmer CJ, Tsai Y, Paszko-Kolva C, Mayer C, Sangermano LR. Detection of Legionella species in sewage and ocean water by polymerase chain reaction, direct fluorescent-antibody, and plate culture methods. Appl Environ Microbiol 1993;59:3618-24.  Back to cited text no. 3
Devos L, Boon N, Verstraete W. Legionella pneumophila in the environment: The occurrence of a fastidious bacterium in oligotrophic conditions. Rev Environ SciBiotechnol 2005;4:61-74.  Back to cited text no. 4
Atlas RM. Legionella: From environmental habitats to disease pathology, detection and control. Environ Microbiol 1999;1:283-93.  Back to cited text no. 5
Hilbi H, Jarraud S, Hartland E, Buchrieser C. Update on Legionnaires' disease: Pathogenesis, epidemiology, detection and control. MolMicrobiol 2010;76:1-11.  Back to cited text no. 6
Roll BM, Fujioka RS. Detection of Legionella bacteria in sewage by polymerase chain reaction and standard culture method. Water SciTechnol 1995;31:409-16.  Back to cited text no. 7
Stout JE, Yu VL. Legionellosis. N Engl J Med 1997;337:682-7.  Back to cited text no. 8
Pascual L, Pérez-Luz S, Amo A, Moreno C, Apraiz D, Catalán V. Detection of Legionella pneumophila in bioaerosols by polymerase chain reaction. Can J Microbiol 2001;47:341-7.  Back to cited text no. 9
Huang SW, Hsu BM, Ma PH, Chien KT. Legionella prevalence in wastewater treatment plants of Taiwan. Water SciTechnol 2009;60:1303-10.  Back to cited text no. 10
Bitton G. Wastewater Microbiology. Fourth edition: Wiley -Blackwell; 2011.p. 437-463  Back to cited text no. 11
Kusnetsov J, Neuvonen LK, Korpio T, Uldum SA, Mentula S, Putus T, et al. Two Legionnaires' disease cases associated with industrial waste water treatment plants: A case report. BMC Infect Dis 2010;10:343.  Back to cited text no. 12
Stetzenbach LD, Alvarez AJ, Buttner MP. Rapid detection of targeted airborne micro-organisms using polymerase chain reaction. Biotechnology Risk Assessment 1999.  Back to cited text no. 13
Medema G, Wullings B, Roeleveld P, van der Kooij D. Risk assessment of Legionella and enteric pathogens in sewage treatment works. Water SciTechnol 2004;4:125-32.  Back to cited text no. 14
Lane D. 16S/23S rRNA sequencing. In: Stackebrandt E, Goodfellow M, editors.Nucleic Acid Techniques in Bacterial Systematics. New York: Wiley; 1991.p. 15-117  Back to cited text no. 15
Asghari FB, Nikaeen M, Hatamzadeh M, Hassanzadeh A. Surveillance of Legionella species in hospital water systems: The significance of detection method for environmental surveillance data. J Water Health 2013;11:713-9.  Back to cited text no. 16
Devos L, Clymans K, Boon N, Verstraete W. Evaluation of nested PCR assays for the detection of Legionella pneumophila in a wide range of aquatic samples. J ApplMicrobiol 2005;99:916-25.  Back to cited text no. 17
Alvarez AJ, Buttner MP, Stetzenbach LD. PCR for bioaerosol monitoring: Sensitivity and environmental interference. Appl Environ Microbiol 1995;61:3639-44.  Back to cited text no. 18
Toze S. PCR and the detection of microbial pathogens in water and wastewater. Water Res 1999;33:3545-56.  Back to cited text no. 19
Stellacci P, Liberti L, Notarnicola M, Haas CN. Hygienic sustainability of site location of wastewater treatment plants: A case study.II. Estimating airborne biological hazard. Desalination 2010;253:106-11.  Back to cited text no. 20