Distribution of Virulence Genes and Sequence-Based Types Among Legionella pneumophila Isolated From the Water Systems of a Tertiary Care Hospital in India

K. Sreenath; Rama Chaudhry; E. V. Vinayaraj; A. B. Dey; S. K. Kabra; Bhaskar Thakur; Randeep Guleria

doi:10.3389/fpubh.2020.596463

Distribution of Virulence Genes and Sequence-Based Types Among Legionella pneumophila Isolated From the Water Systems of a Tertiary Care Hospital in India

K. Sreenath, Rama Chaudhry, E. V. Vinayaraj, A. B. Dey, S. K. Kabra, Bhaskar Thakur, Randeep Guleria

Research output: Contribution to journal › Article › peer-review

5 Scopus citations

Abstract

Background: Legionnaires' disease (LD) is a potentially fatal pneumonia predominantly caused by infection due to Legionella pneumophila although more than 50 other Legionella species are described. Water systems contaminated with Legionella spp. are the implicated sources of Legionnaires' disease. In this study, we aimed to assess Legionella contamination in the water sources of a tertiary care hospital and to determine the virulence properties and molecular characteristics of L. pneumophila environmental isolates. Methods: During May 2015 through August 2018, a total of 201 hospital water samples were tested for L. pneumophila by standardized culture procedures; environmental isolates were examined for the presence of two virulence genes: Legionella vir homolog (lvh) and repeats in structural toxin (rtxA) by PCR. The genotyping of isolates was performed by sequence-based typing (SBT) according to the protocol of the European Study Group for Legionella Infections (ESGLI). Results: L. pneumophila was isolated from 38/201 (18.9%) water samples; among the 46 isolates, the lvh locus was present in 45 (97.8%), the rtxA locus was found in 45 (97.8%), and both loci were found in 44 (95.7%) isolates. A total of 23 sequence types (STs) were identified among the 44 isolates (index of discrimination [IOD] of 0.929), and 11/23 (47.8%) STs were new to the ESGLI database. Conclusions: The study results showed genetic diversity in L. pneumophila isolates from the hospital environment along with a high percentage of pathogenicity loci. Besides, certain STs may have an increased ability to cause legionellosis, thus requires specific infection control and prevention strategies whenever identified.

Original language	English (US)
Article number	596463
Journal	Frontiers in Public Health
Volume	8
DOIs	https://doi.org/10.3389/fpubh.2020.596463
State	Published - Nov 23 2020
Externally published	Yes

Keywords

Legionella
environmental surveillance
genotyping
legionellosis
molecular epidemiology
sequence-based typing
virulence

ASJC Scopus subject areas

Public Health, Environmental and Occupational Health

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10.3389/fpubh.2020.596463

Cite this

@article{75227cf0a75341e68da97abc23d0513e,

title = "Distribution of Virulence Genes and Sequence-Based Types Among Legionella pneumophila Isolated From the Water Systems of a Tertiary Care Hospital in India",

abstract = "Background: Legionnaires' disease (LD) is a potentially fatal pneumonia predominantly caused by infection due to Legionella pneumophila although more than 50 other Legionella species are described. Water systems contaminated with Legionella spp. are the implicated sources of Legionnaires' disease. In this study, we aimed to assess Legionella contamination in the water sources of a tertiary care hospital and to determine the virulence properties and molecular characteristics of L. pneumophila environmental isolates. Methods: During May 2015 through August 2018, a total of 201 hospital water samples were tested for L. pneumophila by standardized culture procedures; environmental isolates were examined for the presence of two virulence genes: Legionella vir homolog (lvh) and repeats in structural toxin (rtxA) by PCR. The genotyping of isolates was performed by sequence-based typing (SBT) according to the protocol of the European Study Group for Legionella Infections (ESGLI). Results: L. pneumophila was isolated from 38/201 (18.9%) water samples; among the 46 isolates, the lvh locus was present in 45 (97.8%), the rtxA locus was found in 45 (97.8%), and both loci were found in 44 (95.7%) isolates. A total of 23 sequence types (STs) were identified among the 44 isolates (index of discrimination [IOD] of 0.929), and 11/23 (47.8%) STs were new to the ESGLI database. Conclusions: The study results showed genetic diversity in L. pneumophila isolates from the hospital environment along with a high percentage of pathogenicity loci. Besides, certain STs may have an increased ability to cause legionellosis, thus requires specific infection control and prevention strategies whenever identified.",

keywords = "Legionella, environmental surveillance, genotyping, legionellosis, molecular epidemiology, sequence-based typing, virulence",

author = "K. Sreenath and Rama Chaudhry and Vinayaraj, {E. V.} and Dey, {A. B.} and Kabra, {S. K.} and Bhaskar Thakur and Randeep Guleria",

note = "Funding Information: We thank Dr. Baharak Afshar, Public Health England, London for providing access to the ESGLI SBT database and for assigning the newly identified allele and sequence types. We acknowledge Dr. Arti Kapil, Dr. Bijay Ranjan Mirdha, Dr. Benu Dhawan, and Dr. Urvashi B Singh for their valuable input and suggestions. We also thank Dr. Arvind Valavane for helpful discussions and Dr. Achuthan C Raghavamenon for critical reading of the manuscript. KS acknowledges the Indian Council for Medical Research (ICMR) for providing Senior Research Fellowship (SRF) during the study period. Publisher Copyright: {\textcopyright} Copyright {\textcopyright} 2020 Sreenath, Chaudhry, Vinayaraj, Dey, Kabra, Thakur and Guleria.",

year = "2020",

month = nov,

day = "23",

doi = "10.3389/fpubh.2020.596463",

language = "English (US)",

volume = "8",

journal = "Frontiers in Public Health",

issn = "2296-2565",

publisher = "Frontiers Media S. A.",

}

TY - JOUR

T1 - Distribution of Virulence Genes and Sequence-Based Types Among Legionella pneumophila Isolated From the Water Systems of a Tertiary Care Hospital in India

AU - Sreenath, K.

AU - Chaudhry, Rama

AU - Vinayaraj, E. V.

AU - Dey, A. B.

AU - Kabra, S. K.

AU - Thakur, Bhaskar

AU - Guleria, Randeep

N1 - Funding Information: We thank Dr. Baharak Afshar, Public Health England, London for providing access to the ESGLI SBT database and for assigning the newly identified allele and sequence types. We acknowledge Dr. Arti Kapil, Dr. Bijay Ranjan Mirdha, Dr. Benu Dhawan, and Dr. Urvashi B Singh for their valuable input and suggestions. We also thank Dr. Arvind Valavane for helpful discussions and Dr. Achuthan C Raghavamenon for critical reading of the manuscript. KS acknowledges the Indian Council for Medical Research (ICMR) for providing Senior Research Fellowship (SRF) during the study period. Publisher Copyright: © Copyright © 2020 Sreenath, Chaudhry, Vinayaraj, Dey, Kabra, Thakur and Guleria.

PY - 2020/11/23

Y1 - 2020/11/23

N2 - Background: Legionnaires' disease (LD) is a potentially fatal pneumonia predominantly caused by infection due to Legionella pneumophila although more than 50 other Legionella species are described. Water systems contaminated with Legionella spp. are the implicated sources of Legionnaires' disease. In this study, we aimed to assess Legionella contamination in the water sources of a tertiary care hospital and to determine the virulence properties and molecular characteristics of L. pneumophila environmental isolates. Methods: During May 2015 through August 2018, a total of 201 hospital water samples were tested for L. pneumophila by standardized culture procedures; environmental isolates were examined for the presence of two virulence genes: Legionella vir homolog (lvh) and repeats in structural toxin (rtxA) by PCR. The genotyping of isolates was performed by sequence-based typing (SBT) according to the protocol of the European Study Group for Legionella Infections (ESGLI). Results: L. pneumophila was isolated from 38/201 (18.9%) water samples; among the 46 isolates, the lvh locus was present in 45 (97.8%), the rtxA locus was found in 45 (97.8%), and both loci were found in 44 (95.7%) isolates. A total of 23 sequence types (STs) were identified among the 44 isolates (index of discrimination [IOD] of 0.929), and 11/23 (47.8%) STs were new to the ESGLI database. Conclusions: The study results showed genetic diversity in L. pneumophila isolates from the hospital environment along with a high percentage of pathogenicity loci. Besides, certain STs may have an increased ability to cause legionellosis, thus requires specific infection control and prevention strategies whenever identified.

AB - Background: Legionnaires' disease (LD) is a potentially fatal pneumonia predominantly caused by infection due to Legionella pneumophila although more than 50 other Legionella species are described. Water systems contaminated with Legionella spp. are the implicated sources of Legionnaires' disease. In this study, we aimed to assess Legionella contamination in the water sources of a tertiary care hospital and to determine the virulence properties and molecular characteristics of L. pneumophila environmental isolates. Methods: During May 2015 through August 2018, a total of 201 hospital water samples were tested for L. pneumophila by standardized culture procedures; environmental isolates were examined for the presence of two virulence genes: Legionella vir homolog (lvh) and repeats in structural toxin (rtxA) by PCR. The genotyping of isolates was performed by sequence-based typing (SBT) according to the protocol of the European Study Group for Legionella Infections (ESGLI). Results: L. pneumophila was isolated from 38/201 (18.9%) water samples; among the 46 isolates, the lvh locus was present in 45 (97.8%), the rtxA locus was found in 45 (97.8%), and both loci were found in 44 (95.7%) isolates. A total of 23 sequence types (STs) were identified among the 44 isolates (index of discrimination [IOD] of 0.929), and 11/23 (47.8%) STs were new to the ESGLI database. Conclusions: The study results showed genetic diversity in L. pneumophila isolates from the hospital environment along with a high percentage of pathogenicity loci. Besides, certain STs may have an increased ability to cause legionellosis, thus requires specific infection control and prevention strategies whenever identified.

KW - Legionella

KW - environmental surveillance

KW - genotyping

KW - legionellosis

KW - molecular epidemiology

KW - sequence-based typing

KW - virulence

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DO - 10.3389/fpubh.2020.596463

M3 - Article

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AN - SCOPUS:85097400335

SN - 2296-2565

VL - 8

JO - Frontiers in Public Health

JF - Frontiers in Public Health

M1 - 596463

ER -

Distribution of Virulence Genes and Sequence-Based Types Among Legionella pneumophila Isolated From the Water Systems of a Tertiary Care Hospital in India

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