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  1. Azhari NN, Ramli SNA, Joseph N, Philip N, Mustapha NF, Ishak SN, et al.
    Acta Trop., 2018 Dec;188:68-77.
    PMID: 30145261 DOI: 10.1016/j.actatropica.2018.08.020
    Leptospirosis is caused by the spirochetal bacterium Leptospira of which rodents are considered the most important reservoir. This study aims to determine and characterize virulent Leptospira species among rodents and small mammals found in human settlements and recreational spots within the Hulu Langat and Gombak districts of Selangor, Malaysia; regions that frequently report probable human leptospirosis cases. Molecular analysis revealed an overall Leptospira detection rate of 14.3% among the 266 small mammals captured, and the human settlements were found to have the highest number of isolates (15.1%), followed by recreational sites (14.5%). The molecular characterization conducted based on the lipL32, secY genes and MLST revealed that the strains belonged to four different species, including; Leptospira interrogans (29; 76.3%; ST50, ST238, ST243), L. kirschneri (5; 13.15%; ST110), L. borgpetersenii (3; 8%; ST143) and L. weilii (1; 2.63%; ST242). The study revealed genotypes of circulating strains among small mammals in Malaysia, which include Leptospira locus ST110 L. kirschneri, ST 50 L. interrogans, ST143 L. borgpetersenii and ST242 L. weilii. Among the small mammals studied, 17/105 (16.2%) Rattus norvegicus, 7/59 (11.9%) of Rattus rattus, 5/24 (20.8%) of Maxomys whiteheadi, 4/18 (22.2%) of Sundamys muelleri, 2/22 (9%), Tupaia gliss, 2/16 (12.5%) Rattus tiomanicus and 1/4 (25%) of Suncus murinus carried pathogenic leptospires. The data from the present study may imply that, in addition to rodents, other small mammals also serve as maintenance hosts for Leptospira. Hence, much remains unknown about Leptospira maintenance hosts, and there is need for further investigation to ascertain the prevailing serovars of pathogenic Leptospira in Malaysia. This will assist in the development of efficient diagnostic assays with improved microscopic agglutination test (MAT) panels, and in the implementation of suitable prevention and control measures.
    Matched MeSH terms: Leptospirosis/microbiology*
  2. Benacer D, Mohd Zain SN, Ahmed AA, Mohd Khalid MK, Hartskeerl RA, Thong KL
    J. Med. Microbiol., 2016 Jun;65(6):574-7.
    PMID: 27058766 DOI: 10.1099/jmm.0.000262
    Matched MeSH terms: Leptospirosis/microbiology
  3. Hin HS, Ramalingam R, Chunn KY, Ahmad N, Ab Rahman J, Mohamed MS
    Am. J. Trop. Med. Hyg., 2012 Oct;87(4):737-40.
    PMID: 22826499 DOI: 10.4269/ajtmh.2012.12-0165
    Co-infection of melioidosis and leptospirosis is uncommon. We report here four such cases, confirmed by blood culture for melioidosis and blood polymerase-chain reaction for leptospirosis, which occurred among rescuers involved in a search and rescue operation for a young man who was suspected to have drowned in Lubuk Yu, a recreational forest in Pahang, Malaysia. Despite treatment, three of the patients died from the co-infection.
    Matched MeSH terms: Leptospirosis/microbiology
  4. Bahaman AR, Ibrahim AL, Stallman ND
    Int. J. Syst. Bacteriol., 1990 Jan;40(1):98-9.
    PMID: 2223603
    A leptospiral isolate from a bovine kidney was found to be antigenically different from all previously recognized serovars of Leptospira interrogans based on the cross-agglutinin absorption test. The new serovar belongs to the Sejroe serogroup, and the name Leptospira interrogans serovar unipertama is proposed for it, with strain K2-1 as the reference strain.
    Matched MeSH terms: Leptospirosis/microbiology*
  5. Vk C, Ty L, Wf L, Ywy WS, An S, S Z, et al.
    Microbiol. Res., 2018 Mar;207:108-115.
    PMID: 29458845 DOI: 10.1016/j.micres.2017.11.015
    Leptospirosis remains one of the most widespread zoonotic diseases caused by spirochetes of the genus Leptospira, which accounts for high morbidity and mortality globally. Leptospiral infections are often found in tropical and subtropical regions, with people exposed to contaminated environments or animal reservoirs are at high risk of getting the infection. Leptospirosis has a wide range of clinical manifestations with non-specific signs and symptoms and often misdiagnosed with other acute febrile illnesses at early stage of infection. Despite being one of the leading causes of zoonotic morbidity worldwide, there is still a gap between pathogenesis and human immune responses during leptospiral infection. It still remains obscure whether the severity of the infection is caused by the pathogenic properties of the Leptospira itself, or it is a consequence of imbalance host immune factors. Hence, in this review, we seek to summarize the past and present milestone findings on the biomarkers of host immune response aspects during human leptospiral infection, including cytokine and other immune mediators. A profound understanding of the interlink between virulence factors and host immune responses during human leptospirosis is imperative to identify potential biomarkers for diagnostic and prognostic applications as well as designing novel immunotherapeutic strategies in future.
    Matched MeSH terms: Leptospirosis/microbiology
  6. Vincent AT, Schiettekatte O, Goarant C, Neela VK, Bernet E, Thibeaux R, et al.
    PLoS Negl Trop Dis, 2019 05;13(5):e0007270.
    PMID: 31120895 DOI: 10.1371/journal.pntd.0007270
    The causative agents of leptospirosis are responsible for an emerging zoonotic disease worldwide. One of the major routes of transmission for leptospirosis is the natural environment contaminated with the urine of a wide range of reservoir animals. Soils and surface waters also host a high diversity of non-pathogenic Leptospira and species for which the virulence status is not clearly established. The genus Leptospira is currently divided into 35 species classified into three phylogenetic clusters, which supposedly correlate with the virulence of the bacteria. In this study, a total of 90 Leptospira strains isolated from different environments worldwide including Japan, Malaysia, New Caledonia, Algeria, mainland France, and the island of Mayotte in the Indian Ocean were sequenced. A comparison of average nucleotide identity (ANI) values of genomes of the 90 isolates and representative genomes of known species revealed 30 new Leptospira species. These data also supported the existence of two clades and 4 subclades. To avoid classification that strongly implies assumption on the virulence status of the lineages, we called them P1, P2, S1, S2. One of these subclades has not yet been described and is composed of Leptospira idonii and 4 novel species that are phylogenetically related to the saprophytes. We then investigated genome diversity and evolutionary relationships among members of the genus Leptospira by studying the pangenome and core gene sets. Our data enable the identification of genome features, genes and domains that are important for each subclade, thereby laying the foundation for refining the classification of this complex bacterial genus. We also shed light on atypical genomic features of a group of species that includes the species often associated with human infection, suggesting a specific and ongoing evolution of this group of species that will require more attention. In conclusion, we have uncovered a massive species diversity and revealed a novel subclade in environmental samples collected worldwide and we have redefined the classification of species in the genus. The implication of several new potentially infectious Leptospira species for human and animal health remains to be determined but our data also provide new insights into the emergence of virulence in the pathogenic species.
    Matched MeSH terms: Leptospirosis/microbiology*
  7. Tan TL, Lee LY, Lim WC
    Med. J. Malaysia, 2018 12;73(6):427-429.
    PMID: 30647223
    The occurrence of Leptospirosis and Escherichia coli coinfection in the post-partum period is a novel case. This report illustrated a previously well woman from a suburban area presented with acute neurological deterioration following a two days history of fever during her puerperal period. Early interventions with fluids, broad spectrum antibiotics and intensive supportive care were given. Despite that, she deteriorated rapidly and developed pulmonary hemorrhage, disseminated intravascular coagulopathy, and multi-organ failure. She succumbed within 12 hours of admission. The knowledge about such fatal co-infections should be disseminated to medical practitioners encountering Leptospirosis infection and general public.
    Matched MeSH terms: Leptospirosis/microbiology
  8. Benacer D, Zain SN, Ooi PT, Thong KL
    Indian J Med Microbiol, 2017 Jan-Mar;35(1):124-128.
    PMID: 28303833 DOI: 10.4103/ijmm.IJMM_15_458
    Leptospirosis is a zoonosis with worldwide distribution caused by pathogenic spirochetes of the genus Leptospira. The aim of this study was to evaluate the susceptibility of isolates obtained from different hosts. A total of 65 Leptospira isolates from humans (n = 1), zoonoses (rat, n = 60; dog, n = 1; swine, n = 1) and environment (n = 2) were tested against six antibiotics. All the isolates were resistant to trimethoprim and sulphamethoxazole and had high MIC toward chloramphenicol (MIC90: 6.25 μg/ml). All except one environment isolate were sensitive to ampicillin, doxycycline and penicillin G.
    Matched MeSH terms: Leptospirosis/microbiology*
  9. Seenichamy A, Bahaman AR, Mutalib AR, Khairani-Bejo S
    Biomed Res Int, 2014;2014:592858.
    PMID: 24860824 DOI: 10.1155/2014/592858
    Leptospirosis is one of the zoonotic diseases in animals and humans throughout the world. LipL21 is one of the important surface-exposed lipoproteins in leptospires and the most effective cross protective immunogenic antigen. It is widely considered as a diagnostic marker for leptospirosis. In this study, we evaluated the serodiagnostic potential of LipL21 protein of Leptospira interrogans serovar Pomona. We have successfully amplified, cloned, and expressed LipL21 in E. coli and evaluated its specificity by immunoblotting. Purified recombinant LipL21 (rLipL21) was inoculated into rabbits for the production of polyclonal antibody. Characterization of the purified IgG antibody against rLipL21 was performed by cross reactivity assay. Only sera from leptospirosis patients and rabbit hyperimmune sera recognized rLipL21 while the nonleptospirosis control sera showed no reaction in immunoblotting. We confirmed that anti-rLipL21-IgG antibody cross reacted with and detected only pathogenic leptospiral species and it did not react with nonpathogenic leptospires and other bacterial species. Results observed showed that anti-rLipL21-IgG antibody has high specificity and sensitivity to leptospires. The findings indicated that the antibody could be used in a diagnostic assay for detection of leptospires or their proteins in the early phase of infection.
    Matched MeSH terms: Leptospirosis/microbiology
  10. Benacer D, Woh PY, Mohd Zain SN, Amran F, Thong KL
    Microbes Environ., 2013;28(1):135-40.
    PMID: 23363618
    Leptospira species were studied in water and soils from selected urban sites in Malaysia. A total of 151 water (n=121) and soil (n=30) samples were collected from 12 recreational lakes and wet markets. All samples were filtered and inoculated into semi-solid Ellinghausen and McCullough modified by Johnson and Harris (EMJH) media supplemented with additional 5-fluorouracil. The cultures were then incubated at 30°C and observed under a dark field microscope with intervals of 10 days. A PCR assay targeting the rrs gene was used to confirm the genus Leptospira among the isolates. Subsequently, the pathogenic status of the isolates was determined using primer sets G1/G2 and Sapro1/Sapro2, which target the secY and rrs genes, respectively. The isolates were identified at serogroup level using the microscopic agglutination test (MAT) while their genetic diversity was assessed by pulsed field gel electrophoresis (PFGE). Based on dark field microscopy, 23.1% (28/121) water and 23.3% (7/30) soil cultures were positive for Leptospira spp. Of the 35 positive cultures, only 8 were pure and confirmed as Leptospira genus by PCR assay. Two out of 8 isolates were confirmed as pathogenic, 5 were saprophytic and one was intermediate. These 8 isolates were negative for the 25 reference hyperimmune rabbit sera tested in the MAT. PFGE showed that all 8 of these environmental Leptospira spp. were genetically diverse. In conclusion, the presence of pathogenic Leptospira spp. in the urban Malaysian environment may indicate and highlight the importance of water screening, especially in recreational lakes, in order to minimize any chance of Leptospira infection.
    Matched MeSH terms: Leptospirosis/microbiology
  11. Bahaman AR, Ibrahim AL
    Vet. Rec., 1986 Sep 27;119(13):325-6.
    PMID: 3776042
    Matched MeSH terms: Leptospirosis/microbiology
  12. Guron G, Holmdahl J, Dotevall L
    Clin. Nephrol., 2006 Dec;66(6):468-71.
    PMID: 17176921 DOI: 10.5414/cnp66468
    A 20-year-old, previously healthy woman, presented with high fever, headache and myalgia 3 days after her return from a holiday in Southeast Asia. Laboratory data on admission demonstrated a pronounced increase in plasma creatinine, marked thrombocytopenia and moderately elevated liver aminotransferases. After having ruled out malaria, dengue fever was primarily suspected and supportive intravenous fluid therapy was initiated. Still, 1 day after admission, platelet counts dropped even further and she became anuric although she did not appear hypovolemic. On day 2 after admission, urine production commenced spontaneously and the patient slowly recovered. All laboratory test results had returned to normal approximately 2 months later. Serological analysis for dengue fever was negative. It turned out that the patient had been trekking in the jungle while in Thailand and we, therefore, analyzed serology for Leptospira spirochetes which was clearly positive. The patient was diagnosed with leptospirosis which is a serious condition associated with a high mortality when complicated by acute renal failure. Differential diagnoses in patients with acute renal failure and tropical infections are reviewed. The importance of early recognition of leptospirosis, and prompt treatment with antibiotics in suspected cases, is emphasized.
    Matched MeSH terms: Leptospirosis/microbiology
  13. Suppiah J, Chan SY, Ng MW, Khaw YS, Ching SM, Mat-Nor LA, et al.
    J. Biomed. Sci., 2017 Jun 28;24(1):40.
    PMID: 28659189 DOI: 10.1186/s12929-017-0344-x
    BACKGROUND: Dengue and leptospirosis infections are currently two major endemics in Malaysia. Owing to the overlapping clinical symptoms between both the diseases, frequent misdiagnosis and confusion of treatment occurs. As a solution, the present work initiated a pilot study to investigate the incidence related to co-infection of leptospirosis among dengue patients. This enables the identification of more parameters to predict the occurrence of co-infection.

    METHOD: Two hundred sixty eight serum specimens collected from patients that were diagnosed for dengue fever were confirmed for dengue virus serotyping by real-time polymerase chain reaction. Clinical, laboratory and demographic data were extracted from the hospital database to identify patients with confirmed leptospirosis infection among the dengue patients. Thus, frequency of co-infection was calculated and association of the dataset with dengue-leptospirosis co-infection was statistically determined.

    RESULTS: The frequency of dengue co-infection with leptospirosis was 4.1%. Male has higher preponderance of developing the co-infection and end result of shock as clinical symptom is more likely present among co-infected cases. It is also noteworthy that, DENV 1 is the common dengue serotype among all cases identified as dengue-leptospirosis co-infection in this study.

    CONCLUSION: The increasing incidence of leptospirosis among dengue infected patients has posed the need to precisely identify the presence of co-infection for the betterment of treatment without mistakenly ruling out either one of them. Thus, anticipating the possible clinical symptoms and laboratory results of dengue-leptospirosis co-infection is essential.

    Matched MeSH terms: Leptospirosis/microbiology
  14. Samsudin S, Sakinah SNS, Malina O, Norliza BA, Noh MA, Fairuz A, et al.
    Trop. Med. Int. Health, 2018 03;23(3):327-333.
    PMID: 29356240 DOI: 10.1111/tmi.13033
    OBJECTIVE: The high prevalence of leptospirosis in humans is of great public health concern, particularly in tropical and subtropical regions. This study aimed to determine the seroprevalence of leptospiral antibodies and distribution of serovars, and to assess the usefulness of enzyme-linked immunosorbent assay (ELISA) as a screening method for leptospiral antibodies in a high-risk healthy community.

    METHODS: Cross-sectional study of 231 market workers and food handlers in wet markets and food premises from two localities in central Malaysia. Respondents' background information was obtained using a questionnaire. Serum samples were tested for leptospiral antibodies using ELISA and microscopic agglutination test (MAT).

    RESULTS: Seroprevalence of leptospirosis among healthy workers was 46.3%. Detection of seropositivity was higher by MAT (46%) than ELISA (15%). We observed high seropositivity among local workers (49%), food handlers (49.5%), females (60.8%) and those aged 34 years and older (46.3%). Local strain LEP175 was the predominant serovar, followed by WHO strain Patoc.

    CONCLUSION: Overall seroprevalence among healthy food handlers and market workers was high in this study. The workplace places susceptible individuals at risk of leptospirosis.

    Matched MeSH terms: Leptospirosis/microbiology*
  15. Mohd Ali MR, Mohamad Safiee AW, Yusof NY, Fauzi MH, Yean Yean C, Ismail N
    J Infect Public Health, 2017 12 23;11(4):578-580.
    PMID: 29277333 DOI: 10.1016/j.jiph.2017.12.008
    BACKGROUND: Environmental sampling provides important information that enhances the understanding of the leptospiral human-environment-animal relationship. Several studies have described the distribution of Leptospira in the environment. However, more targeted sites, that is, areas surrounding leptospirosis patients' houses, remain under-explored. Therefore, this study aims to detect the presence of Leptospira spp. in the residential areas of patients with leptospirosis.

    METHODS: Soil and water samples near leptospirosis patients' residences were collected, processed and cultured into EMJH media. Partial 16S rRNA gene sequencing was performed to confirm the identity of Leptospira.

    RESULTS: EMJH culture and partial 16S rRNA gene sequencing revealed predominant growth of pathogenic Leptospira kmetyi (17%, n=7/42). All tested locations had at least one Leptospira sp., mostly from the soil samples.

    CONCLUSION: More than one species of Leptospira may be present in a sampling area. The most common environmental isolates were pathogenic L. kmetyi.

    Matched MeSH terms: Leptospirosis/microbiology*
  16. Bahaman AR, Ibrahim AL, Stallman ND, Tinniswood RD
    Epidemiol. Infect., 1988 Apr;100(2):239-46.
    PMID: 3356222
    A cross-sectional bacteriological survey of cattle in West Malaysia revealed 14.4% (32/222) had leptospiral infection. Isolates were obtained from all except one herd with prevalence of infection in herds ranging from 0-44.8%. A small number of buffalo urine samples were examined and all of them were found to be negative. A leptospiral isolate obtained from a bovine kidney proved to be a new serovar of Leptospira interrogans and the name unipertama was assigned to it. Six other leptospiral serovars were isolated, namely canicola, australis, javanica, ballum, pomona and hardjo. All six serovars were isolated for the first time in cattle in Malaysia. Cattle in Malaysia appear to be the maintenance host for serovar hardjo. The presence of the other serovars in cattle was probably due to contact with the maintenance hosts, pigs for serovar pomona and rodents for the other three serovars. It appears that the epidemiology of leptospiral infection in cattle in Malaysia is similar to that reported overseas.
    Matched MeSH terms: Leptospirosis/microbiology
  17. Gebriel AM, Subramaniam G, Sekaran SD
    Trop Biomed, 2006 Dec;23(2):194-207.
    PMID: 17322822 MyJurnal
    The detection of leptospires in patient blood in the first week of the disease using PCR provides an early diagnostic tool. PCR using two sets of primers (G1/G2 and B64-I/B64-II) tested with samples seeded with 23 leptospiral strains from pathogenic and non-pathogenic strains was able to amplify leptospiral DNA from pathogenic strains only. Of the 39 antibody negative samples collected from patients suspected for leptospirosis, only 1 sample (2.6%) was PCR positive. Using LSSP-PCR, the G2 primers allowed the characterization of Leptopira species to 10 different genetic signatures which may have epidemiological value in determining species involved in outbreaks. Leptospiral outer membrane proteins from three strains were purified and reacted against patients sera and gave rise to different profiles for pathogenic and non-pathogenic strains. Lymphocytes of mice injected with OMPs proliferated and released IFN(-3) when stimulated in vitro using Leptospira OMP as antigens. This suggests that an immune response could be established using leptospiral OMPs as a putative vaccine. OMPs were also used in a Dot-ELISA to detect antibodies against Leptospira pathogens in humans.
    Matched MeSH terms: Leptospirosis/microbiology*
  18. Nally JE, Arent Z, Bayles DO, Hornsby RL, Gilmore C, Regan S, et al.
    PLoS Negl Trop Dis, 2016 12;10(12):e0005174.
    PMID: 27935961 DOI: 10.1371/journal.pntd.0005174
    The greater white-toothed shrew (Crocidura russula) is an invasive mammalian species that was first recorded in Ireland in 2007. It currently occupies an area of approximately 7,600 km2 on the island. C. russula is normally distributed in Northern Africa and Western Europe, and was previously absent from the British Isles. Whilst invasive species can have dramatic and rapid impacts on faunal and floral communities, they may also be carriers of pathogens facilitating disease transmission in potentially naive populations. Pathogenic leptospires are endemic in Ireland and a significant cause of human and animal disease. From 18 trapped C. russula, 3 isolates of Leptospira were cultured. However, typing of these isolates by standard serological reference methods was negative, and suggested an, as yet, unidentified serovar. Sequence analysis of 16S ribosomal RNA and secY indicated that these novel isolates belong to Leptospira alstonii, a unique pathogenic species of which only 7 isolates have been described to date. Earlier isolations were limited geographically to China, Japan and Malaysia, and this leptospiral species had not previously been cultured from mammals. Restriction enzyme analysis (REA) further confirms the novelty of these strains since no similar patterns were observed with a reference database of leptospires. As with other pathogenic Leptospira species, these isolates contain lipL32 and do not grow in the presence of 8-azagunaine; however no evidence of disease was apparent after experimental infection of hamsters. These isolates are genetically related to L. alstonii but have a novel REA pattern; they represent a new serovar which we designate as serovar Room22. This study demonstrates that invasive mammalian species act as bridge vectors of novel zoonotic pathogens such as Leptospira.
    Matched MeSH terms: Leptospirosis/microbiology*
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