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Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments.

Li L, Qin T, Li Y, Zhou H, Song H, Ren H, Li L, Li Y, Zhao D - Int J Environ Res Public Health (2015)

Bottom Line: All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates.One hundred and seventeen isolates were divided into 49 sequence types.Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes.

View Article: PubMed Central - PubMed

Affiliation: Shijiazhuang Center for Disease Control and Prevention, No.3, Likang Street, Shijiazhuang 050011, China. eryanghualv@aliyun.com.

ABSTRACT
Cooling towers are a source of Legionnaires' disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU)/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%), 6 (25, 20.7%), 5 (12, 9.9%), 8 (8, 6.6%), 3 (6, 5.0%) and 9 (2, 1.6%). All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.

No MeSH data available.


Related in: MedlinePlus

Minimum spanning tree analysis of 117 Legionella pneumophila isolates from industrial cooling towers in Shijiazhang, China. In the minimum spanning tree, the sequence types (STs) are displayed as circles. The size of each circle indicates the number of isolates within this particular type, and the STs are shown in the circles. The colors of the halo surrounding the STs denote types that belong to the same clonal group.
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ijerph-12-12605-f003: Minimum spanning tree analysis of 117 Legionella pneumophila isolates from industrial cooling towers in Shijiazhang, China. In the minimum spanning tree, the sequence types (STs) are displayed as circles. The size of each circle indicates the number of isolates within this particular type, and the STs are shown in the circles. The colors of the halo surrounding the STs denote types that belong to the same clonal group.

Mentions: According to the results of our eBURST analysis, 49 STs belonged to 4 CGs and 4 singleton STs (Figure 3). Of the 4 CGs, CG1, which was the prevalent clonal group, included 44 isolates that belonged to ST1, ST296, ST1177, ST-1656 and ST-1662; and the putative ancestor of CG1 was predicted to be ST1. CG4 was the second prevalent clonal group, included 43 isolates that belonged to 31 STs. The reminders were CG3 (ST59, ST60, ST583, ST-1658 and ST1660), which contained 14 isolates; CG2 (ST154, ST595, ST986 and ST1471), which contained 12 isolates. Of the 4 singleton STs, each were detected in one isolate.


Prevalence and Molecular Characteristics of Waterborne Pathogen Legionella in Industrial Cooling Tower Environments.

Li L, Qin T, Li Y, Zhou H, Song H, Ren H, Li L, Li Y, Zhao D - Int J Environ Res Public Health (2015)

Minimum spanning tree analysis of 117 Legionella pneumophila isolates from industrial cooling towers in Shijiazhang, China. In the minimum spanning tree, the sequence types (STs) are displayed as circles. The size of each circle indicates the number of isolates within this particular type, and the STs are shown in the circles. The colors of the halo surrounding the STs denote types that belong to the same clonal group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4626988&req=5

ijerph-12-12605-f003: Minimum spanning tree analysis of 117 Legionella pneumophila isolates from industrial cooling towers in Shijiazhang, China. In the minimum spanning tree, the sequence types (STs) are displayed as circles. The size of each circle indicates the number of isolates within this particular type, and the STs are shown in the circles. The colors of the halo surrounding the STs denote types that belong to the same clonal group.
Mentions: According to the results of our eBURST analysis, 49 STs belonged to 4 CGs and 4 singleton STs (Figure 3). Of the 4 CGs, CG1, which was the prevalent clonal group, included 44 isolates that belonged to ST1, ST296, ST1177, ST-1656 and ST-1662; and the putative ancestor of CG1 was predicted to be ST1. CG4 was the second prevalent clonal group, included 43 isolates that belonged to 31 STs. The reminders were CG3 (ST59, ST60, ST583, ST-1658 and ST1660), which contained 14 isolates; CG2 (ST154, ST595, ST986 and ST1471), which contained 12 isolates. Of the 4 singleton STs, each were detected in one isolate.

Bottom Line: All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates.One hundred and seventeen isolates were divided into 49 sequence types.Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes.

View Article: PubMed Central - PubMed

Affiliation: Shijiazhuang Center for Disease Control and Prevention, No.3, Likang Street, Shijiazhuang 050011, China. eryanghualv@aliyun.com.

ABSTRACT
Cooling towers are a source of Legionnaires' disease. It is important from a public health perspective to survey industrial cooling towers for the presence of Legionella. Prospective surveillance of the extent of Legionella pollution was conducted at factories in Shijiazhuang, China between March 2011 and September 2012. Overall, 35.7% of 255 industrial cooling tower water samples showed Legionella-positive, and their concentrations ranged from 100 Colony-Forming Units (CFU)/liter to 88,000 CFU/liter, with an average concentration of 9100 CFU/liter. A total of 121 isolates were obtained. All isolates were L. pneumophila, and the isolated serogroups included serogroups 1 (68 isolates, 56.2%), 6 (25, 20.7%), 5 (12, 9.9%), 8 (8, 6.6%), 3 (6, 5.0%) and 9 (2, 1.6%). All 121 isolates were analyzed by pulsed-field gel electrophoresis (PFGE) and 64 different patterns were obtained. All 121 isolates were analyzed sequence-based typing (SBT), a full 7-allele profile was obtained from 117 isolates. One hundred and seventeen isolates were divided into 49 sequence types. Two virulence genes, lvh and rtxA, are analyzed by polymerase chain reaction (PCR). 92.6% (112/121) and 98.3% (119/121) isolates carried lvh and rtxA respectively and 90.9% (110/121) of tested isolates carried both genes. Our results demonstrated high prevalence and genetic polymorphism of L. pneumophila in industrial cooling tower environments in Shijiazhang, China, and the SBT and virulence gene PCR results suggested that the isolates were pathogenic. Improved control and prevention strategies are urgently needed.

No MeSH data available.


Related in: MedlinePlus