ABSTRACT
In order to evaluate the risk of bacterial infection to workers from the sludge in a sewage pit of UOEH Hospital, a bacterial flora analysis based on the molecular-technique using the 16S rRNA gene was performed. Sludge samples taken from five different points in the pit were used. Bacterial numbers of each sludge sample were detected in the range of 1.9 X 10(7) cells/g to 4.4 x 10(8) cells/g. The results of bacterial flora analysis showed that the proportion of known bacteria (similarities of 16S rDNA sequences to that of type strain being 97% or more) and that of unclassified bacteria in the sludge samples were about 20 and 80%, respectively. Regarding the pathogenic bacteria, two Legionella species were detected in two samples, and one Mycobacterium species was detected in one sample. Since the frequency of pathogenic bacteria was equivalent to normal soil, it was concluded that the risk of bacterial infection from the sludge was low.
Subject(s)
Bacterial Infections/prevention & control , Environmental Monitoring/methods , Hospital Design and Construction , Hospitals, University , Legionella/isolation & purification , Mycobacterium/isolation & purification , Occupational Exposure , Risk Assessment , Sewage/microbiology , Soil Microbiology , Japan , Legionella/genetics , Mycobacterium/genetics , Nucleic Acid Amplification Techniques , RNA, Ribosomal, 16S/geneticsABSTRACT
The bacterial flora of 8 sediment samples taken from Doukai Bay in Kitakyushu City in May, 2006 was analyzed by using the culture-independent molecular method. The total bacterial numbers determined by epifluorescence microscopic method were in the range of 2.6 x 10(8) to 6.4 x 10(8) cells/g. The results of bacterial flora analysis suggested that unknown bacterium comprised over 80% of total bacterial flora in the sea sediment samples. Regarding the pathogenic bacteria, although 8 of the Vibrio species, 1 of the Staphylococcus species, and 2 of the Mycobacterium species were detected in the sediment samples, their frequency was low. A large proportion of bacteria related to sulfur circulation, such as sulfur-oxidizing bacteria (10.9 to approximately 30.5%) and sulfate-reducing bacteria (19.6 to approximately 25.1%), was detected in all of the samples from sea sediment. A remarkable difference in bacterial flora between ground soil and sea sediment was clarified by this experiment.
