Investigation On Legionella Pneumophila Contamination Condition And Gene Detection In Central Air Conditioning Recycled Water And Bath Water In Large Hotels Of An Urban District In Beijing

Legionella widely exists in water and solid in nature, but the one which is found in artificial water systems has potential hazard to human health. Legionnaires’ disease is an acute respiratory infection often caused by inhalation of aerosols containing Legionella. The disease has a high mortality and is easy to outbreak. In this study, the following three parts are focus on the research on Legionella pollution investigation and genetic testing analysis in central air conditioning recycled water and bath water in large hotels of an urban district in Beijing, in order to understand the current Legionella contamination status and health management situation, which provides the basis for the health administrative departments to improve legislation and strengthen supervision and management.Part One:Investigation on Legionella Contamination Condition in Central Air Conditioning Recycled Water and bath water in Large Hotels of An Urban District in BeijingObjective to investigate the Legionella contamination condition in central air conditioning recycled water and bath water of large hotels of an urban district in Beijing. Methods29three-star and above hotels in this area were selected by random sampling for the detection of LP and87water samples were collected including45cooling water,13condensed water and29bath water. Use the Legionella diagnostic antisera reagents to identify serotype of Legionella. Results LP was isolated from17hotels of the all (58.62%),and the positive rate of LP in cooling water was40%, which was7.7%in condensed water and24.1%in bath water; the predominant strain was LP serum group1(50%) which occupied14.3%in bath water and14.3%in bath water. Conclusion The contamination condition of LP is not optimistic. It’s necessary to improve legislation and strengthen punishment as well as training to prevent the outbreak of Legionella. Part Two:Investigation on sanitary administration in Central Air Conditioning Recycled Water and bath water in Large Hotels of An Urban District in BeijingObjective to understand the level of sanitary administration in central air conditioning recycled water system of large hotels of an urban district in Beijing. Methods29three-star and above hotels in this area were selected by random sampling for the questionnaire survey of sanitation administration in central air conditioning recycled water system. Do statistical analysis basing on the results of the questionnaire by the SPSS software. Results Legionella detective frequency in cooling water and the sanitation in the engine room have impact on Legionella contamination condition.79.3%of the hotels that were surveyed didn’t disinfect the bath water, so the bath water is a risk factor that had been ignored by both the supervision authority and the hotels. Health supervision should evaluate the level of central air conditioning sanitation administration from multiple aspects and strengthen targeted supervision and monitoring. Improvement of legislation and training is also need to prevent the outbreak of Legionella. Part Three:Detection and Characteristic Analysis of Legionella Gene in Central Air Conditioning in Large Hotels of An Urban District in BeijingObjective to understand the genetic characteristics and hereditary background of experimental strains in central air conditioning recycled water system of large hotels of an urban district in Beijing. Methods29three-star and above hotels in this area were selected by random sampling in central air conditioning recycled water system.29LP and9suspicious strains were collected by LP isolation. Use PCR to amplify the16S RNA in Legionella and detect the gene sequencing and make comparison of amplification. Results37experimental strains had been successfully sequenced of38strains, including34Legionella,1Neisseriaceae and2Francisella. Verified from the genetic level that the contamination condition of Legionella was not optimistic.