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  1. Fulltext Legionella species isolated from cooling towers in Kuala Lumpur
    Ngeow YF, Tan CH, Lim SY
    Med J Malaysia, 1992 Mar;47(1):15-9.
    PMID: 1387443
    Three building complexes in Kuala Lumpur were surveyed for the presence of legionellae in cooling towers. The organisms were grown from 12 out of 46 samples of water collected from 30 towers. L. pneumophila serogroups 1 and 7 were the commonest serogroups isolated. None belonged to the Pontiac subgroup of L. pneumophila serogroup 1.
    Matched MeSH terms: Legionella/isolation & purification*
  2. Fulltext The Blood Microbiome and Health: Current Evidence, Controversies, and Challenges
    Cheng HS, Tan SP, Wong DMK, Koo WLY, Wong SH, Tan NS
    Int J Mol Sci, 2023 Mar 15;24(6).
    PMID: 36982702 DOI: 10.3390/ijms24065633
    Blood is conventionally thought to be sterile. However, emerging evidence on the blood microbiome has started to challenge this notion. Recent reports have revealed the presence of genetic materials of microbes or pathogens in the blood circulation, leading to the conceptualization of a blood microbiome that is vital for physical wellbeing. Dysbiosis of the blood microbial profile has been implicated in a wide range of health conditions. Our review aims to consolidate recent findings about the blood microbiome in human health and to highlight the existing controversies, prospects, and challenges around this topic. Current evidence does not seem to support the presence of a core healthy blood microbiome. Common microbial taxa have been identified in some diseases, for instance, Legionella and Devosia in kidney impairment, Bacteroides in cirrhosis, Escherichia/Shigella and Staphylococcus in inflammatory diseases, and Janthinobacterium in mood disorders. While the presence of culturable blood microbes remains debatable, their genetic materials in the blood could potentially be exploited to improve precision medicine for cancers, pregnancy-related complications, and asthma by augmenting patient stratification. Key controversies in blood microbiome research are the susceptibility of low-biomass samples to exogenous contamination and undetermined microbial viability from NGS-based microbial profiling, however, ongoing initiatives are attempting to mitigate these issues. We also envisage future blood microbiome research to adopt more robust and standardized approaches, to delve into the origins of these multibiome genetic materials and to focus on host-microbe interactions through the elaboration of causative and mechanistic relationships with the aid of more accurate and powerful analytical tools.
    Matched MeSH terms: Legionella*
  3. 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; Legionella pneumophila
  4. The specificity of a rapid method of assay for the presence of Legionella species in water
    Lim EW, Meers PD
    Ann Acad Med Singap, 1989 Jul;18(4):348-51.
    PMID: 2679337
    A rapid method of assay, using a monoclonal antibody linked to alkaline phosphatase, was used for the detection of the Pontiac subgroup of Legionella pneumophila serogroup 1. It was tested for its specificity against 53 strains of Legionella recently isolated from the environment in Singapore and Malaysia. The specificity and sensitivity of this method of assay was confirmed, though there is some concern that the specificity was too narrow, and there are reservations about the criteria suggested for interpreting the results.
    Matched MeSH terms: Legionella/immunology; Legionella/isolation & purification*
  5. 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
  6. 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; Legionella pneumophila
  7. 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*
  8. 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; Legionella pneumophila
  9. 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
  10. Fulltext Molecular detection of bacterial endosymbionts in acanthamoeba spp.: a preliminary study
    Faizah, M. H., Anisah, N., Yusof, S., Noraina, A. R., Adibah, M. R.
    Medicine & Health, 2017;12(2):286-292.
    MyJurnal
    Acanthamoeba spp. merupakan ameba hidup bebas yang biasa ditemui
    di persekitaran. Ia merupakan agen penyebab keratitis Acanthamoeba (AK)
    dan ensefalitis ameba bergranuloma (GAE). Ameba ini juga mampu menjadi
    perumah kepada pelbagai bakteria termasuklah yang bersifat patogenik seperti
    Mycobacterium, Legionella dan Staphylococcus aureus rintang metisilin (MRSA).
    Berdasarkan maklumat ini, satu kajian dijalankan untuk mengesan kehadiran tiga
    bakteria endosimbion berkepentingan perubatan di dalam Acanthamoeba spp. yang
    telah dipencilkan dari bolong penghawa dingin yang terdapat di wad and dewan
    bedah di Pusat Perubatan Universiti Kebangsaan Malaysia. Kehadiran bakteria
    endosimbion ini disaring menggunakan pasangan primer khusus bagi setiap genus
    menggunakan reaksi rantai polimerase (PCR) konvensional dan disahkan dengan
    analisis penjujukan. Dua puluh sembilan (80.56%) pencilan Acanthamoeba spp.
    didapati mengandungi bakteria endosimbion patogenik yang disasarkan dengan
    sekurang-kurangnya satu genus bakteria bagi setiap pencilan. Mycobacterium
    (82.76 %) adalah bakteria yang paling banyak dikesan, diikuti dengan Legionella sp.
    (65.52 %) dan Pseudomonas spp. (62.07 %). Tiada bakteria MRSA dikesan daripada
    mana-mana pencilan dalam kajian ini. Dua endosimbion Mycobacterium yang
    dikenalpasti telah dikelompokkan ke dalam strain Mycobacterium tuberculosis.
    Kami membuat kesimpulan bahawa, kebanyakan Acanthamoeba berpotensi untuk
    menjadi perumah bagi pelbagai bakteria patogenik, namun implikasi interaksi ini
    terhadap patogenisiti kedua-dua organisma masih kurang jelas dan memerlukan
    penyelidikan yang lebih lanjut.
    Matched MeSH terms: Legionella
  11. Legionella species and serogroups in Malaysian water cooling towers: identification by latex agglutination and PCR-DNA sequencing of isolates
    Yong SF, Goh FN, Ngeow YF
    J Water Health, 2010 Mar;8(1):92-100.
    PMID: 20009251 DOI: 10.2166/wh.2009.002
    In this study, we investigated the distribution of Legionella species in water cooling towers located in different parts of Malaysia to obtain information that may inform public health policies for the prevention of legionellosis. A total of 20 water samples were collected from 11 cooling towers located in three different states in east, west and south Malaysia. The samples were concentrated by filtration and treated with an acid buffer before plating on to BCYE agar. Legionella viable counts in these samples ranged from 100 to 2,000 CFU ml(-1); 28 isolates from the 24 samples were examined by latex agglutination as well as 16S rRNA and rpoB PCR-DNA sequencing. These isolates were identified as Legionella pneumophila serogroup 1 (35.7%), L. pneumophila serogroup 2-14 (39%), L. pneumophila non-groupable (10.7%), L. busanensis, L. gormanii, L. anisa and L. gresilensis. L. pneumophila was clearly the predominant species at all sampling sites. Repeat sampling from the same cooling tower and testing different colonies from the same water sample showed concurrent colonization by different serogroups and different species of Legionella in some of the cooling towers.
    Matched MeSH terms: Legionella/isolation & purification*
  12. 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
  13. 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*
  14. Fulltext The microbiological quality of water from dental unit waterlines in Malaysian Armed Forces dental centres
    Ma, Mei Siang, Zalini Yunus, Ahmad Razi Mohammad Yunus, Zukri Ahmad, Haryanti Toosa
    Archives of Orofacial Sciences, 2012;7(1):1-7.
    MyJurnal
    Abstract Water quality in the dental unit waterlines (DUWLs) is important to the patients and dental health care personnel as they are at risk of being infected with opportunistic pathogens such as Pseudomonas or Legionella species. In this study, a total of 86 samples were collected from DUWLs of 19 dental units in 11 Malaysian Armed Forces dental centres (MAFDC). 350 ml water sample was collected in sterile thiosulphite bags from the outlets of 3–way syringe, high speed handpiece, scaler, cup filler, independent water reservoir or the tap of the same surgery respectively. Samples were transported to the laboratory within 24 hours and kept in the refrigerator at 40C. 100ml of each sample was filtered through a 0.45 μm polycarbonate membrane filter. The filter was then inoculated onto plate count agar and incubated at 370 C for 24 hours, after which the formed colonies were enumerated. Another separate 100ml of water sample was poured onto buffered charcoal yeast extract agar and cetrimide agar to culture Legionnella and Pseudomonas respectively. Identification of these bacteria were confirmed by polymerase chain reaction and sequencing. Pseudomonas aeruginosa was detected in 9.5% of the samples but Legionnella was not detected in any of the samples. 77% of the samples met American Dental Association (ADA) recommendation of less than 200 cfu/ml. The result of this study showed that it is difficult if not impossible to eliminate biofilm from the DUWLs. Regular monitor of water quality from DUWL is required to maximise the health of the dental patients and dental health care personnel.
    Matched MeSH terms: Legionella
  15. 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
  16. 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
  17. 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*
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