Culture-Dependent and Culture-Independent Methods in Evaluation of Emission of Enterobacteriaceae from Sewage to the Air and Surface Water

Abstract

The number of Enterobacteriaceae, with particular attention given to the presence of Escherichia coli and Klebsiella pneumoniae, was determined in hospital effluents and municipal wastewater after various stages of purification. The emission of these microorganisms to the ambient air near wastewater treatment plant (WWTP) facilities and to the river water, which is a receiver of the WWTP effluent, was also studied using fluorescence in situ hybridization (FISH) and cultivation methods. The number of Enterobacteriaceae determined by cultivation and fluorescence methods in different kinds of sewage sample ranged from 0.5 × 103 to 2.9 × 106 CFU/ml and from 2.2 × 105 to 1.3 × 108 cells/ml, respectively. Their removal rates during treatment processes were close to 99 %, but the number of these bacteria in the WWTP outflow was quite high and ranged from 5.9 × 103 to 3.5 × 104 CFU/ml and from 1.1 × 105 to 6.1 × 105 cells/ml, respectively. In the river water and the air samples, the number of Enterobacteriaceae was also high and ranged from 4.1 × 103 to 7.9 × 103 CFU/ml and from 3 to 458 CFU/m3, respectively. The numbers of these microorganisms obtained from fluorescence and cultivation methods were statistically and significantly correlated; however, the analysis of the studied samples indicated that the FISH method gave values up to 103-fold times greater than those obtained by the cultivation method. From a sanitary point of view, this means that the number of viable fecal bacteria is systematically underestimated by traditional culture-based methods. Thus, the FISH proves to be a method that could be used to estimate bacterial load, particularly in air samples and less contaminated river water.

Bacterial-aerosol emission from wastewater treatment plant

“…Previous study showed that cell lysis of many gram-negative bacteria produces toxic lipopolysaccharides (LPS) called endotoxins also some strains like E. coli generate verotoxins, and heat-labile enterotoxins, that bring on immune responses [33]. Melbostad et al (1994) surveyed 12 participants from five different WWTP in East Norway.…”

Site-related and seasonal variation of bioaerosol emission in an indoor wastewater treatment station: level, characteristics of particle size, and microbial structure

“…Enterobacter sp. was an important pathogenic bacterium that causes infectious diseases including skin soft tissue infection, respiratory infection, urinary tract infection, and sepsis because of the widespread use of antibiotics (Brodka et al 2012;Korzeniewska and Harnisz 2012). Future studies should focus more on the potential health risk of exposure to Acinetobacter, S. saprophyticus, and Enterobacter sp.…”

The Global Dispersion of Pathogenic Microorganisms by Dust Storms and Its Relevance to Agriculture

“…The combined use of microscopy along with immunology or genetic methods allows identification to the species level. Fluorescence in situ hybridization may allow phylogenetic identification of bacteria (Amann et al, 1996;Korzeniewska and Harnisz, 2012). Electron microscopy has been used to enumerate smaller particles such as viruses and allows their classification based on their morphology (Hanssen et al, 2010;Kim et al, 2013;Whon et al, 2012;Yamaguchi et al, 2012).…”