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Fulltext Plasmodium vivax population structure and transmission dynamics in Sabah Malaysia

Abdullah NR, Barber BE, William T, Norahmad NA, Satsu UR, Muniandy PK, et al.

PLoS One, 2013;8(12):e82553.
PMID: 24358203 DOI: 10.1371/journal.pone.0082553

Despite significant progress in the control of malaria in Malaysia, the complex transmission dynamics of P. vivax continue to challenge national efforts to achieve elimination. To assess the impact of ongoing interventions on P. vivax transmission dynamics in Sabah, we genotyped 9 short tandem repeat markers in a total of 97 isolates (8 recurrences) from across Sabah, with a focus on two districts, Kota Marudu (KM, n = 24) and Kota Kinabalu (KK, n = 21), over a 2 year period. STRUCTURE analysis on the Sabah-wide dataset demonstrated multiple sub-populations. Significant differentiation (F ST = 0.243) was observed between KM and KK, located just 130 Km apart. Consistent with low endemic transmission, infection complexity was modest in both KM (mean MOI = 1.38) and KK (mean MOI = 1.19). However, population diversity remained moderate (H E = 0.583 in KM and H E = 0.667 in KK). Temporal trends revealed clonal expansions reflecting epidemic transmission dynamics. The haplotypes of these isolates declined in frequency over time, but persisted at low frequency throughout the study duration. A diverse array of low frequency isolates were detected in both KM and KK, some likely reflecting remnants of previous expansions. In accordance with clonal expansions, high levels of Linkage Disequilibrium (I A (S) >0.5 [P<0.0001] in KK and KM) declined sharply when identical haplotypes were represented once (I A (S) = 0.07 [P = 0.0076] in KM, and I A (S) = -0.003 [P = 0.606] in KK). All 8 recurrences, likely to be relapses, were homologous to the prior infection. These recurrences may promote the persistence of parasite lineages, sustaining local diversity. In summary, Sabah's shrinking P. vivax population appears to have rendered this low endemic setting vulnerable to epidemic expansions. Migration may play an important role in the introduction of new parasite strains leading to epidemic expansions, with important implications for malaria elimination.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Simian malaria in wild macaques: first report from Hulu Selangor district, Selangor, Malaysia

Akter R, Vythilingam I, Khaw LT, Qvist R, Lim YA, Sitam FT, et al.

Malar J, 2015 Oct 05;14:386.
PMID: 26437652 DOI: 10.1186/s12936-015-0856-3

BACKGROUND: Malaria is a vector-borne parasitic disease which is prevalent in many developing countries. Recently, it has been found that Plasmodium knowlesi, a simian malaria parasite can be life-threatening to humans. Long-tailed macaques, which are widely distributed in Malaysia, are the natural hosts for simian malaria, including P. knowlesi. The aim of the present study was to determine the prevalence of simian malaria parasites in long-tailed macaques in the district of Hulu Selangor, Selangor, Malaysia.
METHODS: A total of 70 blood samples were collected from Macaca fascicularis dwelling in the forest of Hulu Selangor by the Department of Wildlife and National Parks Peninsular Malaysia, Kuala Lumpur, Malaysia. DNA was extracted using PureLink™ Genomic DNA Kits. Conventional and nested PCR were used to detect the genus and species of Plasmodium parasites respectively. In addition, phylogenetic analysis was carried out to confirm the species of Plasmodium parasites.
RESULTS: Thirty-five (50 %) of the 70 samples were positive for Plasmodium using genus-specific primers. These positive samples were then subjected to nested PCR targeting the 18S ribosomal RNA genes to detect all five simian malaria parasites: namely, P. knowlesi, Plasmodium inui, Plasmodium cynomolgi, Plasmodium fieldi, and Plasmodium coatneyi. All five species of simian malaria parasites were detected. Of these, P. inui was the predominant (65.7 %), followed by P. knowlesi (60 %), P. cynomolgi (51.4 %) P. coatneyi (45.7 %) and P. fieldi (2.9 %). A total of nine macaques had mono-infection with P. knowlesi (four), P. cynomolgi (two), P. coatneyi (two) and P. fieldi (one). Eleven of the macaques had dual infections while 12 had triple infections. Three macaques were infected with four species of Plasmodium. Molecular and phylogenetic analysis confirmed the five species of Plasmodium parasites.
CONCLUSION: This study has provided evidence to elucidate the presence of transmission of malaria parasites among the local macaques in Hulu Selangor. Since malaria is a zoonosis, it is important to determine the new control strategies for the control of malaria.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext High frequency of Plasmodium falciparum chloroquine resistance marker (pfcrt T76 mutation) in Yemen: an urgent need to re-examine malaria drug policy

Al-Mekhlafi AM, Mahdy MA, Al-Mekhlafi HM, Azazy AA, Fong MY

Parasit Vectors, 2011;4:94.
PMID: 21619624 DOI: 10.1186/1756-3305-4-94

Malaria remains a significant health problem in Yemen with Plasmodium falciparum being the predominant species which is responsible for 90% of the malaria cases. Despite serious concerns regarding increasing drug resistance, chloroquine is still used for the prevention and treatment of malaria in Yemen. This study was carried out to determine the prevalence of choloroquine resistance (CQR) of P. falciparum isolated from Yemen based on the pfcrt T76 mutation.

Matched MeSH terms: DNA, Protozoan/genetics
First molecular characterization of Cryptosporidium in Yemen

Alyousefi NA, Mahdy MA, Lim YA, Xiao L, Mahmud R

Parasitology, 2013 May;140(6):729-34.
PMID: 23369243 DOI: 10.1017/S0031182012001953

Cryptosporidium is a protozoan parasite of humans and animals and has a worldwide distribution. The parasite has a unique epidemiology in Middle Eastern countries where the IId subtype family of Cryptosporidium parvum dominates. However, there has been no information on Cryptosporidium species in Yemen. Thus, this study was conducted in Yemen to examine the distribution of Cryptosporidium species and subtype families. Fecal samples were collected from 335 patients who attended hospitals in Sana'a city. Cryptosporidium species were determined by PCR and sequence analysis of the 18 s rRNA gene. Cryptosporidium parvum and C. hominis subtypes were identified based on sequence analysis of the 60 kDa glycoprotein (gp60) gene. Out of 335 samples, 33 (9.9%) were positive for Cryptosporidium. Of them, 97% were identified as C. parvum whilst 1 case (3%) was caused by C. hominis. All 7 C. parvum isolates subtyped belonged to the IIaA15G2R1 subtype. The common occurrence of the zoonotic IIa subtype family of C. parvum highlights the potential occurrence of zoonotic transmission of cryptosporidiosis in Yemen. However, this postulation needs confirmation with future molecular epidemiological studies of cryptosporidiosis in both humans and animals in Yemen.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Malaysian child infected with Plasmodium vivax via blood transfusion: a case report

Anthony CN, Lau YL, Sum JS, Fong MY, Ariffin H, Zaw WL, et al.

Malar J, 2013;12:308.
PMID: 24007496 DOI: 10.1186/1475-2875-12-308

Malaria may be a serious complication of blood transfusion due to the asymptomatic persistence of parasites in some donors. This case report highlights the transfusion-transmitted malaria of Plasmodium vivax in a child diagnosed with germ cell tumour. This child had received blood transfusion from three donors and a week later started developing malaria like symptoms. Nested PCR and sequencing confirmed that one of the three donors was infected with P. vivax and this was transmitted to the 12-year-old child. To the best of the authors' knowledge, this is the first reported transfusion-transmitted malaria case in Malaysia.

Matched MeSH terms: DNA, Protozoan/genetics
First molecular identification of Entamoeba moshkovskii in Malaysia

Anuar TS, Al-Mekhlafi HM, Ghani MK, Azreen SN, Salleh FM, Ghazali N, et al.

Parasitology, 2012 Oct;139(12):1521-5.
PMID: 22939193 DOI: 10.1017/S0031182012001485

Entamoeba moshkovskii and Entamoeba dispar are microscopically indistinguishable from the pathogenic species Entamoeba histolytica. Although sporadic cases of human infection with E. moshkovskii have been reported, the amoeba is still considered primarily as a free-living amoeba. A cross-sectional study was carried out among Orang Asli communities in 3 different states of Peninsular Malaysia. Fecal samples were examined by formalin-ether sedimentation and trichrome staining techniques and then single-round PCR assay was used to detect E. moshkovskii. Out of 500 fecal samples examined microscopically, 93 (18·6%) samples were positive for E. histolytica/E. dispar/E. moshkovskii complex cysts and/or trophozoites. PCR products were detected in 106 fecal samples. E. moshkovskii isolates were detected in 13 (12·3%) fecal samples. Of the 13 E. moshkovskii-positive samples, 5 were of single isolation of E. moshkovskii, 6 were also positive for E. dispar, and only 2 samples were positive for E. dispar and E. histolytica. Moreover, 3 E. moshkovskii-positive samples were collected from symptomatic individuals while the remaining 10 samples were from asymptomatic subjects. This is the first report on the identification of E. moshkovskii in Malaysia. Further studies are needed to confirm the pathogenicity of E. moshkovskii infection and determine the epidemiology among Orang Asli communities in Malaysia.

Matched MeSH terms: DNA, Protozoan/genetics
Molecular epidemiology of amoebiasis in Malaysia: highlighting the different risk factors of Entamoeba histolytica and Entamoeba dispar infections among Orang Asli communities

Anuar TS, Al-Mekhlafi HM, Abdul Ghani MK, Abu Bakar E, Azreen SN, Salleh FM, et al.

Int J Parasitol, 2012 Dec;42(13-14):1165-75.
PMID: 23123168 DOI: 10.1016/j.ijpara.2012.10.003

Currently, species-specific information on Entamoeba infections is unavailable in Malaysia and is restricted worldwide due to the re-description of pathogenic Entamoeba histolytica and non-pathogenic Entamoeba dispar and Entamoeba moshkovskii. Therefore, this cross-sectional study was conducted to provide the first known documented data on the true prevalence of these three species in western Malaysia using a molecular method. Another aim of this study was to determine the association of potential risk factors associated with each Entamoeba sp. A total of 500 stool samples from three Orang Asli tribes were randomly collected. The overall prevalence of E. histolytica, E. dispar and E. moshkovskii determined by microscopy was 18.6% (93/500). Molecular analysis revealed that while most Entamoeba-positive individuals were infected with E. dispar (13.4%), followed by E. histolytica (3.2%) and E. moshkovskii (1.0%), the present findings show low prevalence rates of mixed infections with E. histolytica and E. dispar (2%), E. dispar and E. moshkovskii (1.2%) and association infections of E. histolytica, E. dispar and E. moshkovskii (0.4%). Logistical regression analysis indicates that the dynamics of the transmission of the three Entamoeba spp. was different. Of six statistically significant variables observed in the univariate analysis, three were retained as significant risk factors for E. histolytica infection in the logistical regression model. These factors were (i) not washing hands after playing with soil or gardening (Odds ratio (OR)=4.7; 95% confidence level (CI)=1.38, 16.14; P=0.013), (ii) indiscriminate defecation in the river or bush (OR=5.7; 95% CI=1.46, 21.95; P=0.012) and (iii) close contact with domestic animals (OR=5.4; 95% CI=1.36, 2.51; P=0.017). However, subjects with family members who were infected with E. histolytica/E. dispar/E. moshkovskii (OR=3.8; 95 CI=2.11, 6.86; P<0.001) and those who consumed raw vegetables (OR=1.8; 95% CI=1.01, 3.23; P=0.047) were more likely to be infected with E. dispar. On the other hand, no associated factor was identified with E. moshkovskii infection. Nevertheless, diarrhoea (P=0.002) and other gastroenteritis symptoms (P<0.001) were only associated with E. histolytica infection. The present study provides new insight into the distribution and risk factors of E. histolytica, E. dispar and E. moshkovskii infections among Orang Asli communities in Malaysia. Identifying the different risk factors of E. histolytica and E. dispar infections will help in the planning specific strategies in the control and prevention of each infection in the communities. Moreover, it emphasises the need for molecular methods to determine the species-specific prevalence of Entamoeba spp.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Molecular epidemiology of Cryptosporidium in HIV/AIDS patients in Malaysia

Asma I, Sim BL, Brent RD, Johari S, Yvonne Lim AL

Trop Biomed, 2015 Jun;32(2):310-22.
PMID: 26691260 MyJurnal

Cryptosporidiosis is a particular concern in immunocompromised individuals where symptoms may be severe. The aim of this study was to examine the epidemiological and molecular characteristics of Cryptosporidium infections in HIV/AIDS patients in Malaysia in order to identify risk factors and facilitate control measures. A modified Ziehl-Neelsen acid fast staining method was used to test for the presence of Cryptosporidium oocysts in the stools of 346 HIV/AIDS patients in Malaysia. Standard coproscopical methods were used to identify infections with other protozoan or helminths parasites. To identify the species of Cryptosporidium, DNA was extracted and nested-PCR was used to amplify a portion of the SSU rRNA gene. A total of 43 (12.4%) HIV-infected patients were found to be infected with Cryptosporidium spp. Of the 43 Cryptosporidium-positive HIV patients, 10 (23.3%) also harboured other protozoa, and 15 (34.9%) had both protozoa and helminths. The highest rates of cryptosporidiosis were found in adult males of Malay background, intravenous drug users, and those with low CD4 T cell counts (i.e., < 200 cells/mm3). Most were asymptomatic and had concurrent opportunistic infections mainly with Mycobacterium tuberculosis. DNA sequence analysis of 32 Cryptosporidium isolates identified C. parvum (84.3%), C. hominis (6.3%), C. meleagridis (6.3%), and C. felis (3.1%). The results of the present study revealed a high prevalence of Cryptosporidium infection in hospitalized HIV/AIDS patients. The results also confirmed the potential significance of zoonotic transmission of C. parvum in HIV infected patients, as it was the predominant species found in this study. However, these patients were found to be susceptible to a wide range of Cryptosporidium species. Epidemiological and molecular characterization of Cryptosporidium isolates provides clinicians and researchers with further information regarding the origin of the infection, and may enhance treatment and control strategies.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext The detection of pfcrt and pfmdr1 point mutations as molecular markers of chloroquine drug resistance, Pahang, Malaysia

Atroosh WM, Al-Mekhlafi HM, Mahdy MA, Surin J

Malar J, 2012;11:251.
PMID: 22853645 DOI: 10.1186/1475-2875-11-251

Malaria is still a public health problem in Malaysia with chloroquine (CQ) being the first-line drug in the treatment policy of uncomplicated malaria. There is a scarcity in information about the magnitude of Plasmodium falciparum CQ resistance. This study aims to investigate the presence of single point mutations in the P. falciparum chloroquine-resistance transporter gene (pfcrt) at codons 76, 271, 326, 356 and 371 and in P. falciparum multi-drug resistance-1 gene (pfmdr1) at codons 86 and 1246, as molecular markers of CQ resistance.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Genetic diversity of Plasmodium falciparum isolates from Pahang, Malaysia based on MSP-1 and MSP-2 genes

Atroosh WM, Al-Mekhlafi HM, Mahdy MA, Saif-Ali R, Al-Mekhlafi AM, Surin J

Parasit Vectors, 2011;4:233.
PMID: 22166488 DOI: 10.1186/1756-3305-4-233

Malaria is still a public health problem in Malaysia especially in the interior parts of Peninsular Malaysia and the states of Sabah and Sarawak (East Malaysia). This is the first study on the genetic diversity and genotype multiplicity of Plasmodium falciparum in Malaysia.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Plasmodium knowlesi malaria during pregnancy

Barber BE, Bird E, Wilkes CS, William T, Grigg MJ, Paramaswaran U, et al.

J Infect Dis, 2015 Apr 1;211(7):1104-10.
PMID: 25301955 DOI: 10.1093/infdis/jiu562

BACKGROUND: Plasmodium knowlesi is the commonest cause of malaria in Malaysia, but little is known regarding infection during pregnancy.
METHODS: To investigate comparative risk and consequences of knowlesi malaria during pregnancy, we reviewed (1) Sabah Health Department malaria-notification records created during 2012-2013, (2) prospectively collected data from all females with polymerase chain reaction (PCR)-confirmed malaria who were admitted to a Sabah tertiary care referral hospital during 2011-2014, and (3) malaria microscopy and clinical data recorded at a Sabah tertiary care women and children's hospital during 2010-2014.
RESULTS: During 2012-2013, 774 females with microscopy-diagnosed malaria were notified, including 252 (33%), 172 (20%), 333 (43%), and 17 (2%) with Plasmodium falciparum infection, Plasmodium vivax infection, Plasmodium malariae/Plasmodium knowlesi infection, and mixed infection, respectively. Among females aged 15-45 years, pregnancy was reported in 18 of 124 (14.5%), 9 of 93 (9.7%), and 4 of 151 (2.6%) P. falciparum, P. vivax, and P. malariae/P. knowlesi notifications respectively (P = .002). Three females with knowlesi malaria were confirmed as pregnant: 2 had moderate anemia, and 1 delivered a preterm low-birth-weight infant. There were 17, 7, and 0 pregnant women with falciparum, vivax, and knowlesi malaria, respectively, identified from the 2 referral hospitals.
CONCLUSIONS: Although P. knowlesi is the commonest malaria species among females in Sabah, P. knowlesi infection is relatively rare during pregnancy. It may however be associated with adverse maternal and pregnancy outcomes.
KEYWORDS: Plasmodium knowlesi; malaria; maternal anemia; pregnancy; preterm delivery

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext A pentaplex real-time polymerase chain reaction assay for detection of four species of soil-transmitted helminths

Basuni M, Muhi J, Othman N, Verweij JJ, Ahmad M, Miswan N, et al.

Am J Trop Med Hyg, 2011 Feb;84(2):338-43.
PMID: 21292911 DOI: 10.4269/ajtmh.2011.10-0499

Soil-transmitted helminth infections remain a major public health burden in low- and middle-income countries. The traditional diagnosis by microscopic examination of fecal samples is insensitive and time-consuming. In this study, a pentaplex real-time polymerase chain reaction (PCR) was evaluated for the simultaneous detection of Ancylostoma, Necator americanus, Ascaris lumbricoides, and Strongyloides stercoralis. The results were compared with those obtained by conventional parasitological diagnostic methods. Real-time PCR was positive in 48 of 77 samples (62.3%) and microscopic examination was positive in six samples (7.8%) only (P < 0.05). In conclusion, the real-time PCR assay described in this study provides a specific and sensitive diagnostic tool for the detection of these four helminth species in epidemiological studies and monitoring of treatment programs.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Whole genome sequencing of amplified Plasmodium knowlesi DNA from unprocessed blood reveals genetic exchange events between Malaysian Peninsular and Borneo subpopulations

Benavente ED, Gomes AR, De Silva JR, Grigg M, Walker H, Barber BE, et al.

Sci Rep, 2019 07 08;9(1):9873.
PMID: 31285495 DOI: 10.1038/s41598-019-46398-z

The zoonotic Plasmodium knowlesi parasite is the most common cause of human malaria in Malaysia. Genetic analysis has shown that the parasites are divided into three subpopulations according to their geographic origin (Peninsular or Borneo) and, in Borneo, their macaque host (Macaca fascicularis or M. nemestrina). Whilst evidence suggests that genetic exchange events have occurred between the two Borneo subpopulations, the picture is unclear in less studied Peninsular strains. One difficulty is that P. knowlesi infected individuals tend to present with low parasitaemia leading to samples with insufficient DNA for whole genome sequencing. Here, using a parasite selective whole genome amplification approach on unprocessed blood samples, we were able to analyse recent genomes sourced from both Peninsular Malaysia and Borneo. The analysis provides evidence that recombination events are present in the Peninsular Malaysia parasite subpopulation, which have acquired fragments of the M. nemestrina associated subpopulation genotype, including the DBPβ and NBPXa erythrocyte invasion genes. The NBPXb invasion gene has also been exchanged within the macaque host-associated subpopulations of Malaysian Borneo. Our work provides strong evidence that exchange events are far more ubiquitous than expected and should be taken into consideration when studying the highly complex P. knowlesi population structure.

Matched MeSH terms: DNA, Protozoan/genetics*
Fulltext A simple, high-throughput, colourimetric, field applicable loop-mediated isothermal amplification (HtLAMP) assay for malaria elimination

Britton S, Cheng Q, Sutherland CJ, McCarthy JS

Malar J, 2015;14:335.
PMID: 26315027 DOI: 10.1186/s12936-015-0848-3

To detect all malaria infections in elimination settings sensitive, high throughput and field deployable diagnostic tools are required. Loop-mediated isothermal amplification (LAMP) represents a possible field-applicable molecular diagnostic tool. However, current LAMP platforms are limited by their capacity for high throughput.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Isolation and characterization of Acanthamoeba spp. from air-conditioners in Kuala Lumpur, Malaysia

Chan LL, Mak JW, Low YT, Koh TT, Ithoi I, Mohamed SM

Acta Trop, 2011 Jan;117(1):23-30.
PMID: 20858455 DOI: 10.1016/j.actatropica.2010.09.004

During a study on the quality of the indoor environment, Acanthamoeba spp. were detected in 20 out of 87 dust samples collected from air-conditioners installed in a four-story campus building located in Kuala Lumpur, Malaysia. Twenty-one cloned Acanthamoeba isolates designated as IMU1 to IMU21 were established from the positive primary cultures. Five species were identified from the 16 isolates according to the morphological criteria of Pussard and Pons; i.e. A. castellanii, A. culbertsoni, A. griffini, A. hatchetti and A. polyphaga. Species identities for the remaining five isolates (IMU4, IMU5, IMU15, IMU20 and IMU21), however, could not be determined morphologically. At genotypic characterization, these isolates were placed into T3 (IMU14); T5 (IMU16 and IMU17) and T4 (all the remaining isolates). To predict the potential pathogenicity of these Acanthamoeba isolates, thermo- and osmotolerance tests were employed; many isolates were predicted as potential human pathogens based on the outcome of these tests. This is the first time potentially pathogenic Acanthamoeba have been isolated from air-conditioners in Malaysia.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext High lipid storage in vacoular forms of subtype 6 Blastocystis sp. in ostrich

Chandrasekaran H, Govind SK, Panchadcharam C, Bathmanaban P, Raman K, Thergarajan G

Parasit Vectors, 2014;7:469.
PMID: 25358755 DOI: 10.1186/s13071-014-0469-7

Blastocystis sp., a widely prevalent intestinal protozoan parasite is found in a wide range of animals, including humans. The possibility of zoonotic transmission to human from birds especially ostriches led us to investigate on the cross infectivity of Blastocystis sp. isolated from the ostrich feces as well as the phenotypic and subtype characteristics. There is a need to investigate this especially with the rising number of ostrich farms due to the growing global ostrich industry.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Hexaplex PCR detection system for identification of five human Plasmodium species with an internal control

Chew CH, Lim YA, Lee PC, Mahmud R, Chua KH

J Clin Microbiol, 2012 Dec;50(12):4012-9.
PMID: 23035191 DOI: 10.1128/JCM.06454-11

Malaria remains one of the major killers of humankind and persists to threaten the lives of more than one-third of the world's population. Given that human malaria can now be caused by five species of Plasmodium, i.e., Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale, and the recently included Plasmodium knowlesi, there is a critical need not only to augment global health efforts in malaria control but also, more importantly, to develop a rapid, accurate, species-sensitive/species-specific, and economically effective diagnostic method for malaria caused by these five species. Therefore, in the present study, a straightforward single-step hexaplex PCR system targeting five human Plasmodium 18S small-subunit rRNAs (ssu rRNAs) was designed, and the system successfully detected all five human malaria parasites. In addition, this system enables the differentiation of single infection as well as mixed infections up to the two-species level. This assay was validated with 50 randomly blinded test and 184 clinical samples suspected to indicate malaria. This hexaplex PCR system is not only an ideal alternative for routine malaria diagnosis in laboratories with conventional PCR machines but also adds value to diagnoses when there is a lack of an experienced microscopist or/and when the parasite morphology is confusing. Indeed, this system will definitely enhance the accuracy and accelerate the speed in the diagnosis of malaria, as well as improve the efficacy of malaria treatment and control, in addition to providing reliable data from epidemiological surveillance studies.

Matched MeSH terms: DNA, Protozoan/genetics
Molecular characterization and expression of a putative ATPase domain from Eimeria tenella

Chong SP, Jangi MS, Wan KL

J. Biochem. Mol. Biol. Biophys., 2002 Apr;6(2):123-8.
PMID: 12186768

VCP (Valosin-Containing Protein), a member of the AAA (ATPases Associated to a variety of cellular Activities) family of proteins, possesses a duplicated highly conserved ATPase domain. An expressed sequence tag (EST), representing a clone from the Eimeria tenella merozoite cDNA library, was found to have high similarity to VCP genes from other organisms. A complete sequence derived from the corresponding clone (designated eth060) shows amino acid identity of 42-62% with other members of the VCP subfamily. Sequence analysis identified a putative ATPase domain in the eth060 sequence. This domain was PCR-amplified using gene-specific primers and cloned into a pBAD/Thio-TOPO expression vector. Expression in Escherichia coli demonstrated that the putative ATPase domain, which consists of 414 amino acid residues, produced a fusion protein of approximately 60 kDa in size.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Population expansion and gene flow in Giardia duodenalis as revealed by triosephosphate isomerase gene

Choy SH, Mahdy MA, Al-Mekhlafi HM, Low VL, Surin J

Parasit Vectors, 2015;8:454.
PMID: 26373536 DOI: 10.1186/s13071-015-1084-y

Giardia duodenalis is a protozoan parasite that can cause significant diarrhoeal diseases. Knowledge of population genetics is a prerequisite for ascertaining the invasion patterns of this parasite. In order to infer evolutionary patterns that could not be uncovered based on the morphological features, a population genetic study with the incorporation of molecular marker was carried out to access the genetic structure of G. duodenalis isolated from the Malaysian population and the global populations.

Matched MeSH terms: DNA, Protozoan/genetics
Fulltext Phylogenetic analysis of simian Plasmodium spp. infecting Anopheles balabacensis Baisas in Sabah, Malaysia

Chua TH, Manin BO, Daim S, Vythilingam I, Drakeley C

PLoS Negl Trop Dis, 2017 Oct;11(10):e0005991.
PMID: 28968395 DOI: 10.1371/journal.pntd.0005991

BACKGROUND: Anopheles balabacensis of the Leucospyrus group has been confirmed as the primary knowlesi malaria vector in Sabah, Malaysian Borneo for some time now. Presently, knowlesi malaria is the only zoonotic simian malaria in Malaysia with a high prevalence recorded in the states of Sabah and Sarawak.
METHODOLOGY/PRINCIPAL FINDINGS: Anopheles spp. were sampled using human landing catch (HLC) method at Paradason village in Kudat district of Sabah. The collected Anopheles were identified morphologically and then subjected to total DNA extraction and polymerase chain reaction (PCR) to detect Plasmodium parasites in the mosquitoes. Identification of Plasmodium spp. was confirmed by sequencing the SSU rRNA gene with species specific primers. MEGA4 software was then used to analyse the SSU rRNA sequences and bulid the phylogenetic tree for inferring the relationship between simian malaria parasites in Sabah. PCR results showed that only 1.61% (23/1,425) of the screened An. balabacensis were infected with one or two of the five simian Plasmodium spp. found in Sabah, viz. Plasmodium coatneyi, P. inui, P. fieldi, P. cynomolgi and P. knowlesi. Sequence analysis of SSU rRNA of Plasmodium isolates showed high percentage of identity within the same Plasmodium sp. group. The phylogenetic tree based on the consensus sequences of P. knowlesi showed 99.7%-100.0% nucleotide identity among the isolates from An. balabacensis, human patients and a long-tailed macaque from the same locality.
CONCLUSIONS/SIGNIFICANCE: This is the first study showing high molecular identity between the P. knowlesi isolates from An. balabacensis, human patients and a long-tailed macaque in Sabah. The other common simian Plasmodium spp. found in long-tailed macaques and also detected in An. balabacensis were P. coatneyi, P. inui, P. fieldi and P. cynomolgi. The high percentage identity of nucleotide sequences between the P. knowlesi isolates from the long-tailed macaque, An. balabacensis and human patients suggests a close genetic relationship between the parasites from these hosts.

Matched MeSH terms: DNA, Protozoan/genetics

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