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Fulltext Occurrence of virulent genes among environmental isolates of Legionella pneumophila serogroup 1 strains from various parts of peninsular Malaysia

Arushothy R, Ahmad N

Trop Biomed, 2008 Dec;25(3):259-61.
PMID: 19287368

Legionella pneumophila are intracellular pathogens, associated with human disease, attributed to the presence and absence of certain virulent genes. In this study, virulent gene loci (lvh and rtxA regions) associated with human disease were determined. Thirty-three cooling tower water isolates, isolated between 2004 to 2006, were analyzed for the presence of these genes by PCR method. Results showed that 19 of 33 (57.5%) of the L. pneumophila serogroup 1 isolates have both the genes. Six (18.2%) of the isolates have only the lvh gene and 2 (6.1%) of the isolates have only the rtxA gene. However, both genes were absent in 6 (18.2%) of the L. pneumophila isolates. The result of our study provides some insight into the presence of the disease causing L. pneumophila serogroup 1 in the environment. Molecular epidemiological studies will provide better understanding of the prevalence of the disease in Malaysia.

Matched MeSH terms: Legionella pneumophila/classification; Legionella pneumophila/genetics*; Legionella pneumophila/pathogenicity
Fulltext Isolation of Legionella pneumophila from hospital cooling towers in Johor, Malaysia

Abdul Samad BH, Suhaili MR, Baba N, Rajasekaran G

Med J Malaysia, 2004 Aug;59(3):297-304.
PMID: 15727373 MyJurnal

Water-based cooling towers and their water supply at two hospitals in Johor were surveyed for the presence Legionella pneumophila. L. pneumophila were grown from 19 (76%) out of 25 collected water samples. One hospital cooling tower was contaminated with L. pneumophila serogroup 1.

Matched MeSH terms: Legionella pneumophila/isolation & purification*
Isolation of Legionella from cooling towers and potable water systems in hospital and non-medical buildings in a university campus

Chin KS, Rosli AA, Wee CSL, Ngeow YF

JUMMEC, 2005;8:23-27.

Six cooling towers and eleven sources of potable water in a university campus in Kuala Lumpur were surveyed for the presence of legionellae. One nonmedical building cooling tower and three hot water systems from one ward of the hospital tested positive for Legionella, two of which contained Legionella pneumophila serogroup 1. The identification of Legionella was based on isolation, immunofluorescence and polymerase chain reaction (PCR).

Matched MeSH terms: Legionella pneumophila
Detection of Legionella pneumophila antigens in patients' sera using monoclonal antibodies

Normaznah Y, Saniah K, Noor Rain A, Norazah A, Azizah MR, Sabiha P

Malays J Pathol, 1998 Dec;20(2):95-8.
PMID: 10879269

Three monoclonal antibodies (McAb) were produced against soluble antigens of Legionella pneumophila serogroup 1 which was cultured on BCYE agar. The McAbs were all of the IgM isotype. The McAbs were used in the McAb-based ELISA for detection of circulating L. pneumophila antigens in 186 sera collected from patients with symptoms and signs suggestive of atypical pneumonia. The normal reference optical (OD) density value of each of the McAbs was determined using 44 sera collected from healthy blood donors. The antigen positivity rates for the McAbs 1C7.2B, 2B2.10F and 2B2.11E were 11.3%, 7.7% and 22.2% respectively. Antigen positivity of the McAb 2B2.10F was significantly higher in the younger age group (p < 0.05). There is no significant association between the antigen positivity with age and sex for all the McAbs. There was no cross-reaction demonstrated between the McAbs with other bacterial antigens.

Matched MeSH terms: Legionella pneumophila/immunology*; Legionella pneumophila/isolation & purification
Fulltext Molecular Detection of Legionella: Moving on From mip

Yong SF, Tan SH, Wee J, Tee JJ, Sansom FM, Newton HJ, et al.

Front Microbiol, 2010;1:123.
PMID: 21687766 DOI: 10.3389/fmicb.2010.00123

The detection of Legionella pneumophila in environmental and clinical samples is frequently performed by PCR amplification of the mip and/or 16S rRNA genes. Combined with DNA sequencing, these two genetic loci can be used to distinguish different species of Legionella and identify L. pneumophila. However, the recent Legionella genome sequences have opened up hundreds of possibilities for the development of new molecular targets for detection and diagnosis. Ongoing comparative genomics has the potential to fine tune the identification of Legionella species and serogroups by combining specific and general genetic targets. For example, the coincident detection of LPS biosynthesis genes and virulence genes may allow the differentiation of both pathogen and serogroup without the need for nucleotide sequencing. We tested this idea using data derived from a previous genomic subtractive hybridization we performed between L. pneumophila serogroup 1 and L. micdadei. Although not yet formally tested, these targets serve as an example of how comparative genomics has the potential to improve the scope and accuracy of Legionella molecular detection if embraced by laboratories undertaking Legionella surveillance.

Matched MeSH terms: Legionella pneumophila
A Hospital-based Study on the Local Epidemiology of Pneumonia Including the Contribution of Legionella Pneumonia

Lourdesamy Anthony AI, Zam Z, Hussin N

Malays J Med Sci, 2020 Dec;27(6):79-88.
PMID: 33447136 DOI: 10.21315/mjms2020.27.6.8

Background: In real-life practice, only 20% of hospitalised pneumonia cases have an identified etiology. The usage of Legionella urine antigen test (LUAT) in developed nations revolutionised case detection rates. Accordingly, our objectives were to study the microbiological etiology for hospitalised pneumonia patients and the diagnosis of Legionella pneumonia.
Methods: A prospective, observational single-centre study was conducted where all 504 cases that were consecutively admitted for pneumonia were enrolled. Blood and sputum samples obtained were used to identify pathogens using standard microbiological culture methods. The urine samples collected were tested using the ImmunocatchTMLegionella immunochromatographic (ICT) urine antigen test.
Results: A microbiological diagnosis was only achieved in 104 cases (20.6%) and a Gram-negative infection predominance was observed. Culture-positive cases required longer hospitalisation (8.46 days versus 5.53 days; P < 0.001) and the higher usage of antipseudomonal antibiotics (23.1% versus 8.3%; P < 0.001). Only 3 cases (0.6%) were diagnosed with Legionella pneumonia.
Conclusion: The local pathogen distribution is diverse compared to other regions. Culture-negative pneumonia is common and significantly differs from culture-positive pneumonia. Legionella pneumophila serotype 1 is not a common cause of pneumonia and LUAT did not help demystify the cause of culture-negative pneumonia.

Matched MeSH terms: Legionella pneumophila
Fulltext Development of multiplex real-time PCR for the rapid detection of five bacterial causes of community acquired pneumonia

Al-Marzooq F, Imad MA, How SH, Kuan YC

Trop Biomed, 2011 Dec;28(3):545-56.
PMID: 22433883 MyJurnal

Establishing a microbial diagnosis for patients with community-acquired pneumonia (CAP) is still challenging and is often achieved in only 30-50% of cases. Polymerase chain reaction (PCR) has been shown to be more sensitive than conventional microbiological methods and it could help to increase the microbial yield for CAP patients. This study was designed to develop, optimize and evaluate multiplex real-time PCR as a method for rapid differential detection of five bacterial causes of CAP namely Streptococcus pneumoniae, Burkholderia pseudomallei and atypical bacterial pathogens, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella pneumophila. Duplex and triplex real-time PCR assays were developed using five sets of primers and probes that were designed based on an appropriate specific gene for each of the above CAP pathogens. The performance of primers for each organism was tested using SYBR Green melt curve analysis following monoplex realtime PCR amplification. Monoplex real-time PCR assays were also used to optimize each primers-probe set before combining them in multiplex assays. Two multiplex real-time PCR assays were then optimized; duplex assay for the differential detection of S. pneumoniae and B. pseudomallei, and triplex assay for the atypical bacterial pathogens. Both duplex and triplex real-time PCR assays were tested for specificity by using DNA extracted from 26 related microorganisms and sensitivity by running serial dilutions of positive control DNAs. The developed multiplex real-time PCR assays shall be used later for directly identifying CAP causative agents in clinical samples.

Matched MeSH terms: Legionella pneumophila/genetics; Legionella pneumophila/isolation & purification
Detection of IgM antibodies against Legionella pneumophila serogroup 1 in Malaysian blood donors and patients with respiratory illnesses: evaluation of enzyme-linked immunosorbent assay and indirect immunofluorescence assay

Tay ST, Lakhbeer Singh HK, Ramasame SD, Vadivelu J

Jpn J Infect Dis, 2009 Sep;62(5):409-10.
PMID: 19762997
Matched MeSH terms: Legionella pneumophila/immunology*
Fulltext Detection of enterotoxin targeted entFM and hblA genes by inoculating Bacillus cereus (Strain BC1) into ready-to-eat food (RTF) and drink samples using polymerase chain reaction (PCR)

Nooratiny, I., Sahilah, A.M.

International Food Research Journal, 2013;20(4):1895-1899.
MyJurnal

Detection of enterotoxin by targeting entFM and hblA genes in Bacillus cereus BC1 strain inoculated into ready to eat food (RTF) and drink samples using polymerase chain reaction (PCR) was conducted. The B. cereus BC1 strain was confirmed as a Bacillus diarrhoeal enterotoxin (BDE) when tested by a commercially available Enzyme-linked immunosorbent assay-BDE immunoassay (ELISA-BDE immunoassay, TECRA). In the specificity study, both enterotoxin genes were detected on chromosomal DNA of B. cereus BC1 strain by showing a specific band of 1269 bp (entFM) and 874 bp (hblA), respectively. However, none of the target genes were detected for the other 15 genomic DNA bacteria (B. cereus (ATCC 11779), B. subtilis (ATCC 6633), Campylobacter jejuni (ATCC 29428), C. coli (Jabatan Kimia Malaysia, JKM), Clostridium perfringen (ATCC 13124), Enterobacter sakazaki (ATCC 51329), Escherichia coli (ATCC 43888), E. coli (ATCC 11735), Legionella pneumophila (ATCC 33152), Listeria monocytogenes (ATCC 35967), Salmonella typhi (IMR), S. enteritidis (ATCC 13076), S. typhimurium (ATCC 14028), Shigella flexeneri (ATCC 12022) and Vibrio cholerae bengal (Institute Medical Research (IMR), Malaysia) examined. The detection limit of both genes was 0.1 ng of genomic DNA. Thus, in the presence study it is evidence that the PCR analysis targeting enterotoxin of entFM and hblA genes are suitable and useful in detecting enterotoxic B. cereus in RTFs and drinks contaminated sample.

Matched MeSH terms: Legionella pneumophila
Fulltext Frequency of Mycoplasma pneumoniae, Legionella pneumophila and Chlamydia spp. among patients with atypical pneumonia in Tehran

Noori Goodarzi N, Pourmand MR, Rajabpour M, Arfaatabar M, Mosadegh M, Syed Mohamad SA

New Microbes New Infect, 2020 Sep;37:100744.
PMID: 32953125 DOI: 10.1016/j.nmni.2020.100744

Mycoplasma pneumoniae, Legionella pneumophila and Chlamydia pneumoniae are the most common bacterial agents, which account for 15-40%, 2-15% and 5-10% of atypical community-acquired pneumonia (CAP) respectively. These agents are mostly associated with infection in the outpatient setting. The aim of this study was to evaluate the frequency of these pathogens among patients with CAP attending outpatient clinics in Tehran. A cross-sectional study was carried out of 150 patients attending to educational hospitals in Tehran with CAP. M. pneumoniae, L. pneumophila and Chlamydia spp. were detected by PCR assay, targeting the P1 adhesion gene, macrophage infectivity potentiator (mip) gene and 16S rRNA gene respectively from throat swabs obtained from each patient. A total of 86 (57.3%) of 150 patients were women; median age was 50 years (interquartile range, 35-65 years). M. pneumoniae, L. pneumophila and Chlamydia spp. were detected in 37 (24.7%), 25 (16.7%) and 11 (7.3%) patients respectively; of these, 66 patients (44%) were infected at least by one of these three pathogens. The frequency of L. pneumophila was significantly higher among patients over 60 years old (p 0.03). Coinfection was detected in seven patients (4.7%); six were infected by M. pneumoniae and L. pneumophila, and only one was infected by L. pneumophila and Chlamydia spp. M. pneumoniae was the most prevalent agent of atypical CAP, and L. pneumophila was more likely to infect elderly rather than younger people. Further studies on the prevalence of CAP and its aetiologic agents are needed to improve the diagnosis and treatment of CAP patients.

Matched MeSH terms: Legionella pneumophila
An Asian study on the prevalence of atypical respiratory pathogens in community-acquired pneumonia

Ngeow YF, Suwanjutha S, Chantarojanasriri T, Wang F, Saniel M, Alejandria M, et al.

Int J Infect Dis, 2005 May;9(3):144-53.
PMID: 15840455

In many parts of Asia, the inaccessibility and high cost of diagnostic tests have hampered the study of community-acquired pneumonia (CAP) caused by atypical respiratory pathogens.

Matched MeSH terms: Legionella pneumophila/isolation & purification*