Korean Journal of Microbiology (미생물학회지)

The Microbiological Society of Korea (한국미생물학회)
권호 표지
DOI QR코드

DOI QR Code

Meta-Analysis of Risk Factors for Contamination of Environmental Waters by Legionella

환경수계 레지오넬라균 오염 지표의 메타분석

  • Received : 2013.12.11
  • Accepted : 2013.12.24
  • Published : 2013.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

To identify risk factors for Legionella contamination, water quality variables routinely measured in examination of natural and city waters were meta-analyzed for significance of correlation to Legionella incidences. For evaluation of abundance of Escherichia coli as a risk factor, which is currently used as an indicator of Legionella contamination in an official guideline in Korea, odds ratio (OR) of above-cutoff total coliform counts for Legionella presence/absence was used as the effect size in the meta-analysis. The OR was estimated as 1.05 (0.36-3.12, 95% CI), and the probability of having identical odds reached 0.92. Also, ORs from individual studies showed significant heterogeneity (P=0.008), which contributed to 63% of total variance of the ORs. In the case of heterotrophic plate count (HPC), the OR for Legionella presence/absence was 2.72 (2.04-3.63) with highly significant deviation from identical odds (P<0.0001). ORs from different studies were seemingly homogeneous ($Q_{df=8}$=12.7, P=0.12). Turbidity and concentrations of chlorine, iron ion and cupper ion were other routine variables that could be considered as risk factors. However, statistical measures from different studies were not uniform enough to develop an appropriate effect size while the number of studies reporting the variables was also small (3-5). In conclusion, HPC appeared to be appropriate as indicator of Legionella contamination, rather than fecal bacteria contamination. HPC may imply abundance of habitats (amoebas and biofilms) of Legionella in water. This result warrants further studies for standardizing protocols and cutoff values to infer Legionella risks from HPC.

레지오넬라균에 의한 자연환경의 수체 및 각종 시설 용수의 오염도를 조사하는데 적용할 수 있는 오염도 지표를 통상적으로 측정되는 수질항목 중에서 선정하려는 목적으로, 다양한 수체에 적용된 수질항목들이 레지오넬라균 오염도와 어느 정도 유의한 상관관계를 맺는 지에 관한 메타분석을 실시하였다. 환경부의 수질관리 지침에서 레지오넬라균 오염도의 위험지수로 사용되고 있는 대장균의 경우, 총대장균군 항목과 레지오넬라균 검출여부의 교차비(odds ratio; OR)로 분석하였는데, 교차비는 1.05(0.36-3.12, 95% CI)로, 오즈의 차이가 없을 확률이 0.92에 달하였다. 또한, 총대장균군 자료는 유의한 수준의 자료간 이질성을 보였으며(P=0.008), 무작위적인 자료간 이질성이 전체 교차비 변량의 63%를 차지하였다. 종속영양세균수(HPC)의 교차비가 2.72(2.04-3.63)로 1 보다 매우 유의하게 높았고(P<0.0001), 자료간 이질성이 없었다($Q_{df=8}$=12.7, P=0.12). 탁도와 염소농도, 철과 구리 이온의 농도 등이 레지오넬라균 검출여부와 함께 조사되는 통상적 수질항목이었으나, 자료수의 부족과 정량 자료의 통일성 부족으로 적절한 메타분석이 수행 될 수 없었다. 결론적으로, 분변균의 오염도 보다, 수중 레지오넬라균 서식지(아메바와 생물막)의 양을 표현하는 종속영양세균수가 레지오넬라균의 오염도 지표로 활용될 수 있을 것으로 사료되며, 실험 방법의 표준화와 경계값을 판단하는 후속 연구가 필요하다.

Keywords

References

  1. Allen, M.J., Edberg, S.C., and Reasoner, D.J. 2004. Heterotrophic plate count bacteria?-what is their significance in drinking water? Int. J. Food Microbiol. 92, 265-274. https://doi.org/10.1016/j.ijfoodmicro.2003.08.017
  2. Bargellini, A., Marchesi, I., Righi, E., Ferrari, A., Cencetti, S., Borella, P., and Rovesti, S. 2011. Parameters predictive of Legionella contamination in hot water systems: association with trace elements and heterotrophic plate counts. Water Res. 45, 2315-2321. https://doi.org/10.1016/j.watres.2011.01.009
  3. Borenstein, M., Hedges, L., Higgins, J., and Rothstein, H. 2005. Comprehensive Meta-Analysis. Biostat, Englewood, NJ, USA.
  4. CDC Korea. 2012. Guideline for Management of Legionnaires' Disease. Center for Disease Control and Prevention, Korea, Osong, Korea.
  5. Cho, K.S., Kim, S.B., Park, D.S., Ahn, T.Y., and Yu, B.C. 2011. Development of Surveillance Technology for Harmful Microorganisms in Environments under Climate Change. National Institute of Environemental Research Korea, Incheon, Korea.
  6. Diederen, B.M.W. 2008. Legionella spp. and Legionnaires' disease. J. Infect. 56, 1-12. https://doi.org/10.1016/j.jinf.2007.09.010
  7. Edagawa, A., Kimura, A., Doi, H., Tanaka, H., Tomioka, K., Sakabe, K., Nakajima, C., and Suzuki, Y. 2008. Detection of culturable and nonculturable Legionella species from hot water systems of public buildings in Japan. J. Appl. Microbiol. 105, 2104-2114. https://doi.org/10.1111/j.1365-2672.2008.03932.x
  8. Hsu, B.M., Chen, C.H., Wan, M.T., and Cheng, H.W. 2006. Legionella prevalence in hot spring recreation areas of Taiwan. Water Res. 40, 3267-3273. https://doi.org/10.1016/j.watres.2006.07.007
  9. Hsu, B.M., Lin, C.L., and Shih, F.C. 2009. Survey of pathogenic free-living amoebae and Legionella spp. in mud spring recreation area. Water Res. 43, 2817-2828. https://doi.org/10.1016/j.watres.2009.04.002
  10. Huang, S.W., Hsu, B.M., Ma, P.H., and Chien, K.T. 2009. Legionella prevalence in wastewater treatment plants of Taiwan. Water Sci. Technol. 60, 1303-1310. https://doi.org/10.2166/wst.2009.410
  11. Kim, K.Y., Kim, Y.S., Song, J.C., Lee, S.J., Kim, S.U., Choi, T.Y., Park, W.S., and Lee, C.M. 2003. Comparison of methods for identification and the effects on Legionella pneumophila of the cooling towers in Seoul. J. Korean Soc. Occup. Environ. Hyg. 13, 1-19.
  12. Lee, I.S. and Zo, Y.G. 2013. Quantitative microbiological risk analysis of Legionella infection of children from recreational activities in interactive fountains. Korean J. Microbiol. submitted.
  13. Ministry of Environment Korea. 2010. Guideline for Management of Water Quality in Interactive Waterscape Facilities.
  14. Mouchtouri, V., Velonakis, E., Tsakalof, A., Kapoula, C., Goutziana, G., Vatopoulos, A., Kremastinou, J., and Hadjichristodoulou, C. 2007. Risk factors for contamination of hotel water distribution systems by Legionella species. Appl. Environ. Microbiol. 73, 1489-1492. https://doi.org/10.1128/AEM.02191-06
  15. Park, H.K., Jung, E.Y., Jung, J.M., and Yu, P.J. 2007. Detection and distribution of bacterial pathogens in raw water and during water treatment process by polymerase chain reaction. J. Life Sci. (Korea) 17, 1374-1380. https://doi.org/10.5352/JLS.2007.17.10.1374
  16. Qin, T., Yan, G., Ren, H., Zhou, H., Wang, H., Xu, Y., Zhao, M., Guan, H., Li, M., and Shao, Z. 2013. High prevalence, genetic diversity and intracellular growth ability of Legionella in hot spring environments. PLoS One 8, e59018. https://doi.org/10.1371/journal.pone.0059018
  17. Reasoner, D.J. 2004. Heterotrophic plate count methodology in the United States. Int. J. Food Microbiol. 92, 307-315. https://doi.org/10.1016/j.ijfoodmicro.2003.08.008
  18. Sartory, D.P. 2004. Heterotrophic plate count monitoring of treated drinking water in the UK: a useful operational tool. Int. J. Food Microbiol. 92, 297-306. https://doi.org/10.1016/j.ijfoodmicro.2003.08.006
  19. Serrano-Suarez, A., Dellunde, J., Salvado, H., Cervero-Arago, S., Mendez, J., Canals, O., Blanco, S., Arcas, A., and Araujo, R. 2013. Microbial and physicochemical parameters associated with Legionella contamination in hot water recirculation systems. Environ. Sci. Pollut. Res. Int. 20, 5534-5544. https://doi.org/10.1007/s11356-013-1557-5
  20. Viechtbauer, W. 2010. Conducting meta-analyses in R with the metafor package. J. Stat. Software 36, 1-48.

Cited by

  1. An Enzyme-linked Immunosorbent Assay Strip Sensor for the Detection of Legionella Pneumophila vol.25, pp.5, 2014, https://doi.org/10.14478/ace.2014.1083