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  1. Cools P, van Lieshout L, Koelewijn R, Addiss D, Ajjampur SSR, Ayana M, et al.
    PLoS Negl Trop Dis, 2020 Jun;14(6):e0008231.
    PMID: 32544158 DOI: 10.1371/journal.pntd.0008231
    BACKGROUND: Nucleic acid amplification tests (NAATs) are increasingly being used as diagnostic tools for soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, Necator americanus, Ancylostoma duodenale and A. ceylanicum), Strongyloides stercoralis and Schistosoma in human stool. Currently, there is a large diversity of NAATs being applied, but an external quality assessment scheme (EQAS) for these diagnostics is lacking. An EQAS involves a blinded process where test results reported by a laboratory are compared to those reported by reference or expert laboratories, allowing for an objective assessment of the diagnostic performance of a laboratory. In the current study, we piloted an international EQAS for these helminths (i) to investigate the feasibility of designing and delivering an EQAS; (ii) to assess the diagnostic performance of laboratories; and (iii) to gain insights into the different NAAT protocols used.

    METHODS AND PRINCIPAL FINDINGS: A panel of twelve stool samples and eight DNA samples was validated by six expert laboratories for the presence of six helminths (Ascaris, Trichuris, N. americanus, Ancylostoma, Strongyloides and Schistosoma). Subsequently this panel was sent to 15 globally dispersed laboratories. We found a high degree of diversity among the different DNA extraction and NAAT protocols. Although most laboratories performed well, we could clearly identify the laboratories that were poorly performing.

    CONCLUSIONS/SIGNIFICANCE: We showed the technical feasibility of an international EQAS for the NAAT of STHs, Strongyloides and Schistosoma. In addition, we documented that there are clear benefits for participating laboratories, as they can confirm and/or improve the diagnostic performance of their NAATs. Further research should aim to identify factors that explain poor performance of NAATs.

    Matched MeSH terms: Helminths/isolation & purification
  2. Ngwe Tun MM, Muthugala R, Nabeshima T, Soe AM, Dumre SP, Rajamanthri L, et al.
    PLoS One, 2020;15(6):e0234508.
    PMID: 32555732 DOI: 10.1371/journal.pone.0234508
    Dengue virus (DENV) infection remains a major public health concern in many parts of the world, including Southeast Asia and the Americas. Sri Lanka experienced its largest dengue outbreak in 2017. Neurological symptoms associated with DENV infection have increasingly been reported in both children and adults. Here, we characterize DENV type 2 (DENV-2) strains, which were isolated from cerebrospinal fluid (CSF) and/or serum of patients with dengue encephalitis. Acute serum and CSF samples from each patient were subjected to dengue-specific non-structural protein 1 (NS1) antigen test, IgM and IgG enzyme-linked immunosorbent assay (ELISA), virus isolation, conventional and real-time polymerase chain reaction (PCR), and next-generation sequencing (NGS). Among the 5 dengue encephalitis patients examined, 4 recovered and 1 died. DENV-2 strains were isolated from serum and/or CSF samples of 3 patients. The highest viral genome levels were detected in the CSF and serum of the patient who succumbed to the illness. A phylogenetic tree revealed that the DENV-2 isolates belonged to a new clade of cosmopolitan genotype and were genetically close to strains identified in China, South Korea, Singapore, Malaysia, Thailand, and the Philippines. According to the NGS analysis, greater frequencies of nonsynonymous and synonymous mutations per gene were identified in the nonstructural genes. The full genomes of serum- and CSF-derived DENV-2 from the same patient shared 99.7% similarity, indicating that the virus spread across the blood-brain barrier. This is the first report to describe neurotropic DENV-2 using whole-genome analysis and to provide the clinical, immunological, and virological characteristics of dengue encephalitis patients during a severe dengue outbreak in Sri Lanka in 2017.
    Matched MeSH terms: Dengue Virus/isolation & purification
  3. Quek A, Kassim NK, Lim PC, Tan DC, Mohammad Latif MA, Ismail A, et al.
    Pharm Biol, 2021 Dec;59(1):964-973.
    PMID: 34347568 DOI: 10.1080/13880209.2021.1948065
    CONTEXT: Melicope latifolia (DC.) T. G. Hartley (Rutaceae) was reported to contain various phytochemicals including coumarins, flavonoids, and acetophenones.

    OBJECTIVE: This study investigates the antidiabetic and antioxidant effects of M. latifolia bark extracts, fractions, and isolated constituents.

    MATERIALS AND METHODS: Melicope latifolia extracts (hexane, chloroform, and methanol), fractions, and isolated constituents with varying concentrations (0.078-10 mg/mL) were subjected to in vitro α-amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory assay. Molecular docking was performed to study the binding mechanism of active compounds towards α-amylase and DPP-4 enzymes. The antioxidant activity of M. latifolia fractions and compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene bleaching assays.

    RESULTS: Melicope latifolia chloroform extract showed the highest antidiabetic activity (α-amylase IC50: 1464.32 μg/mL; DPP-4 IC50: 221.58 μg/mL). Fractionation of chloroform extract yielded four major fractions (CF1-CF4) whereby CF3 showed the highest antidiabetic activity (α-amylase IC50: 397.68 μg/mL; DPP-4 IC50: 37.16 μg/mL) and resulted in β-sitosterol (1), halfordin (2), methyl p-coumarate (3), and protocatechuic acid (4). Isolation of compounds 2-4 from the species and their DPP-4 inhibitory were reported for the first time. Compound 2 showed the highest α-amylase (IC50: 197.53 μM) and β-carotene (88.48%) inhibition, and formed the highest number of molecular interactions with critical amino acid residues of α-amylase. The highest DPP-4 inhibition was exhibited by compound 3 (IC50: 911.44 μM).

    DISCUSSION AND CONCLUSIONS: The in vitro and in silico analyses indicated the potential of M. latifolia as an alternative source of α-amylase and DPP-4 inhibitors. Further pharmacological studies on the compounds are recommended.

    Matched MeSH terms: Plant Extracts/isolation & purification
  4. Ahmad A, Dada AC, Usup G
    PMID: 24974655
    Partial gene sequences of phenylalanyl-tRNA synthase alpha subunit (pheS) and RNA polymerase alpha subunit (rpoA) were evaluated for species delineation and detection of recombination among enterococci populations recovered from a bathing beach impacted by low tide river flow. At inter-species level, a maximum similarity of 86.5% and 94.8% was observed among the enterococci pheS and rpoA sequence, respectively. A superimposed plot of delimited pairwise similarity values obtained for 266 pair-wise observations revealed that while there was a harmony between species identity obtained from both genes, pheS was more discriminatory than rpoA. The difference was more pronounced for inter-species comparison. A number of putative recombination events between indigenous and non-indigenous strains was detected based on a library of aligned sequences. Virulence genes cyl, esp, gelE and asa were detected in 7, 22, 100 and 63%, respectively among river isolates but at lower proportion of 0, 20, 67 and 42%, respectively among beach water isolates. Random amplified polymorphic DNA profiling presented evidence suggesting low tide river as a source of fecal enterococci entering the recreation beach water. Multilocus sequence typing analysis of a number of Enterococcus faecalis isolates presented four sequence types, ST59, 117, 181 and 474. The presence of genetically diverse fecal enterococci with associated virulence traits and a background of recombination events in surface recreational water could present a potential public health risk.
    Matched MeSH terms: Enterococcus/isolation & purification
  5. Norahmad NA, Abdullah NR, Yaccob N, Jelip J, Dony JF, Ruslan KF, et al.
    PMID: 22299399
    Chloroquine (CQ) remains the first line drug for the prevention and treatment of malaria in Malaysia in spite of the fact that resistance to CQ has been observed in Malaysia since the 1960s. CQ-resistance is associated with various mutations in pfcrt, which encodes a putative transporter located in the digestive vacuolar membrane of P. falciparum. Substitution of lysine (K) to threonine (T) at amino acid 76 (K76T) in pfcrt is the primary genetic marker conferring resistance to CQ. To determine the presence of T76 mutation in pfcrt from selected areas of Kalabakan, Malaysia 619 blood samples were screened for P. falciparum, out of which 31 were positive. Blood samples were collected on 3 MM Whatman filter papers and DNA was extracted using QIAmp DNA mini kit. RFLP-PCR for the detection of the CQ-resistant T76 and sensitive K76 genotype was carried out. Twenty-five samples were shown to have the point mutation in pfcrt whereas the remaining samples were classified as CQ-sensitive (wild-type). In view of the fact that CQ is the first line anti-malarial drug in Malaysia, this finding could be an important indication that treatment with CQ may no longer be effective in the future.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  6. Nissapatorn V, Leong TH, Lee R, Init-Ithoi, Ibrahim J, Yen TS
    PMID: 21710842
    Toxoplasmosis is an important parasitic disease in immunosuppressed patients. This prospective study was conducted to determine the seroprevalence, associated risk factors and the incidence of clinically confirmed toxoplasmosis among renal patients at the University of Malaya Medical Center, Kuala Lumpur, Malaysia. We interviewed 247 renal patients, each of whom answered an epidemiological questionnaire, and collected blood samples for measurement of anti-Toxoplasma IgG and IgM antibodies by ELISA. Overall seroprevalence of latent toxoplasmosis was observed in 126 (51%) renal patients. Race (Malays), marital status (married) and primary level of education, were all factors associated with a greater chance of Toxoplasma infection. A case of clinically confirned toxoplasmosis was diagnosed in a renal transplant recipient as a result of immunosuppression. Based on the findings obtained, this preliminary study shows a high prevalence of latent toxoplasmosis in renal patients. Risk factors may have significantly contributed to Toxoplasma acquisition in these patients. We recommend further studies be carried out to monitor for trends in toxoplasmosis among immunosuppressed patients.
    Matched MeSH terms: Toxoplasma/isolation & purification
  7. Kassim FM, Izati MN, TgRogayah TA, Apandi YM, Saat Z
    PMID: 21706934
    Accurate and timely diagnosis of dengue virus is important for early detection of dengue virus infection. In this study, the usefulness of the dengue NS1 antigen test was evaluated as a routine, rapid diagnostic test for dengue virus infection. A total of 208 sera from patients suspected of having dengue virus infection were collected and tested for dengue antibody, dengue genome and dengue NS1 antigen. Dengue antibody test, dengue PCR test and dengue antigen test were able to detect dengue virus infection from Days 1 to 8 in 72.8, 52.8 and 44.0% of samples, respectively. Of the 208 sera tested, 69.2% (144/208) of the acute sera were positive for dengue virus infection based on IgM antibody, IgG antibody, NS1 antigen and PCR tests. Thirty-two point two percent of the samples (67/208) were found positive for dengue NS1 antigen, 38.5% (80/208) were PCR positive, 40.9% (85/208) were IgM positive and 36.1% (75/208) were IgG positive for dengue virus. The results reveal the detection rate of dengue virus infection was similar for PCR and dengue antibody (65.9%) and for NS1 antigen and dengue antibody (62.0%) combinations. Therefore, the dengue NS1 antigen test can be used to complement the current antibody test used in peripheral laboratories. Thus, the combination of the NS1 antigen and antibody tests could increase the diagnostic efficiency for early diagnosis of dengue infection.
    Matched MeSH terms: Dengue Virus/isolation & purification
  8. Zurina Z, Rohani A, Neela V, Norlijah O
    PMID: 23413711
    Group B beta-hemolytic streptococcus (GBS) sepsis is a serious bacterial infection in neonates, with significant morbidity and mortality. We report here a neonate with late onset GBS infection manifesting as a urinary tract infection (UTI) in an infant presenting with prolonged neonatal jaundice. The pathogenesis of this late onset is postulated.
    Matched MeSH terms: Streptococcus agalactiae/isolation & purification
  9. Lee HL, Phong TV, Rohani A
    PMID: 23413698
    This study was conducted to determine the inhibitory effects of ribavirin and hydroxyurea on dengue virus replication in Aedes aegypti mosquitoes. Female Ae. aegypti mosquitoes were infected with dengue-2 virus and fed ribavirin at a dose of 0.3 mg/ml and/or hydroxyurea at a dose of 6 mg/ml via artificial membrane feeding technique. The virus in infected mosquitoes was isolated using C6/36 cell culture. Peroxidase-antiperoxidase (PAP) staining was used to detect dengue-infected C6/36 cells and to quantify the level of infection by determining the presence of infected cells. In mosquitoes treated with ribavirin alone, hydroxyurea alone or both drugs in combination had reductions in dengue infection rates of 87.72, 89.47 and 95.61%, respectively. The mortalities of female Ae. aegypti mosquitoes fed with these drugs were significantly higher than the control. Ribavirin also had an inhibitory effect on the fecundity of female Ae. aegypti mosquitoes.
    Matched MeSH terms: Dengue Virus/isolation & purification
  10. Tee MH, Lee YY, Majid NA, Noori NM, Raj SM
    PMID: 23682433
    We studied asymptomatic primary schoolchildren in northeastern Malaysia with light to moderate trichuriasis to determine the effect of albendazole treatment on growth rates and TNF-alpha levels. Thirty-seven schoolchildren aged 6-7 years with stool samples positive for Trichuris trichiura and negative for other geohelminths and protozoa were randomized to receive albendazole 400 mg or a placebo daily for 2 days. Anthropometric parameters at baseline, 3, 6 and 12 months were compared between the 2 groups. The placebo group had a significantly greater increase in height (p = 0.04) than the albendazole treatment group. There were no significant differences in urinary TNF-alpha levels (p = 0.8) between the 2 groups and no significant changes between baseline and 1 month post-treatment levels. Further studies are needed to determine the etiology of this apparent association between the albendazole treatment group and the delay in growth rate at 6 months post-treatment.
    Matched MeSH terms: Trichuris/isolation & purification
  11. Kaur G, Madhavan M, Basri AH, Sain AH, Hussain MS, Yatiban MK, et al.
    PMID: 15689086
    The objective of this study was to determine the sensitivity, specificity, positive (PPV), and negative predictive values (NPV) of Diff-Quik-stained gastric imprint cytology smears in the detection of H. pylori compared with histology. Air-dried imprint smears of gastric biopsies from 150 patients were stained by the Diff-Quik method in the endoscopy suite and examined for H. pylori, providing results within minutes. The presence of inflammation and intestinal metaplasia were documented. The same biopsy was processed and stained with H&E and Warthin-Starry stains, and reviewed by a different pathologist blind to the imprint cytology results. Ninety-four of the 150 patients were male with a mean age of 50 years. Based on histology, the H. pylori prevalence was very low at 8%. The sensitivity and specificity of imprint cytology in the detection of H. pylori were 83.3% and 100%, respectively. The PPV and NPV were 100% and 98.6%, respectively. There were two false negatives and no false positives. A combination of imprint cytology and histology achieved 100% sensitivity. Imprint smears did not provide added value over histology with regards to inflammation and metaplasia. Gastric imprint smears stained with Diff-Quik method is a rapid, cheap, and reliable method for the detection of H. pylori and have their best results when complemented with histology.
    Matched MeSH terms: Helicobacter pylori/isolation & purification*
  12. Hii JL, Chee KC, Vun YS, Awang J, Chin KH, Kan SK
    PMID: 9185261
    The district of Kudat has one of the highest and most persistent malaria transmission levels in Sabah, Malaysia, with annual parasite incidence of 102 per 1,000 inhabitants per year. Due to this situation and the failure of DDT spraying to control malaria, a community participation health program (Sukarelawan Penjagaan Kesihatan Primer or SPKP) was developed as an adjunct to current anti-malarial measures during 1987-1991. SPKP is made up of unpaid community workers known as village health volunteers (VHVs). VHVs are selected by a village development and security committees training and supervision a member of the Vector-Borne Diseases Control Program (VBDCP). The beneficiaries of SPKP consisted primarily of Runggus people and other remote, and mobile populations who visit the home of a VHV for diagnosis and treatment. This group of febrile patients and their children who attend a participating school submit finger prick blood and personal details to the VHV. and receive a presumptive treatment for malaria. Thick and thin blood smears are examined by a VBDCP microscopist who then prepare and forward a radical or curative treatment to the VHV so that it can be administered to the microscopically-positive patient free of charge. Between June 1987 to June 1991, VHVs from 32 kampungs (villages) and 22 schools collected 56,245 slides representing 24.7% of total slide collection compared to 74.9% collected by passive case detection (PCD) posts in health centers and district hospital. The average volunteer treated 11.8 (range 10.4-13.4) and 31.4 (range 26-49) patients per month in kampungs and schools respectively. In contrast, non-SPKP posts in a district hospital, health centers and flying doctor service treated an average of 616.3 patients per month (range 134.8-1032.8). The slide positivity rate of blood smears taken by VHVs was 8.43% compared with 7.37% for non-SPKP posts. Average slide collection and slide positivity rates varied considerably from one community to another, despite their close geographic proximity. The monthly number of VHV-diagnosed patients from the school and kampungs communities and the monthly number of true malaria patients in the two groups were significantly correlated. Sustainability of SPKP was linked to an ongoing process of social change which involved co-operative networking between the government health sector and the community. This in turn provided a stimulus for malaria abatement efforts. When Runggus people themselves control and maintain ownership of community-based malaria programs, the function of SPKP as a malaria surveillance system and an antimalarial drug distribution network is vastly improved.
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  13. Zaidah AR, Chan YY, Asma HS, Abdullah S, Nurhaslindawati AR, Salleh M, et al.
    PMID: 18564692
    This cross-sectional study determined the prevalence of cryptosporidiosis in HIV-infected patients using polymerase chain reaction (PCR). Stool specimens were collected from HIV infected patients who were admitted to Hospital Raja Perempuan Zainab II, Kota Bharu, Malaysia, for various indications from December 2004 to December 2005. A modified acid-fast stain was performed on the direct stool smears, then the stool specimens were further tested using nested PCR targeting the 18S rRNA gene of Cryptosporidium parvum, with a built-in internal control (IC). Out of 59 samples, 11 were positives. Nested PCR identified a total of nine samples (16%) compared to microscopy, which identified only three samples. All PCR negative results showed IC amplicons, suggesting that these samples were true negatives and were not due to inhibition of PCR. This study highlights the importance of molecular diagnosis in determining the true prevalence and epidemiology of C. parvum.
    Matched MeSH terms: Cryptosporidium parvum/isolation & purification*
  14. Zarina AL, Hamidah A, Zulkifli SZ, Jamal R
    PMID: 15916058
    Thalassemia is the commonest hemoglobinopathy in Malaysia. Patients with thalassemia major are transfusion dependent, and a large proportion of them will require splenectomy. As this particular group of patients is immunocompromized, overwhelming sepsis is a recognized complication. We report a series of three patients who all developed intra-abdominal abscesses following splenectomy.
    Matched MeSH terms: Klebsiella pneumoniae/isolation & purification
  15. Rohela M, Jamaiah I, Menon J, Rachel J
    PMID: 15916055
    Fasciolopsiasis is a disease caused by the largest intestinal fluke, Fasciolopsis buski. The disease is endemic in the Far East and Southeast Asia. Human acquires the infection after eating raw freshwater plants contaminated with the infective metacercariae. There has been no report of fasciolopsiasis either in man or in animal in Malaysia. We are reporting the first case of fasciolopsiasis in Malaysia in a 39-year-old female farmer, a native of Sabah (East Malaysia). This patient complained of cough and fever for a duration of two weeks, associated with loss of appetite and loss of weight. She had no history of traveling overseas. Physical examination showed pallor, multiple cervical and inguinal lymph nodes and hepatosplenomegaly. Laboratory investigations showed that she had iron deficiency anemia. There was leukocytosis and a raised ESR. Lymph node biopsy revealed a caseating granuloma. Stool examination was positive for the eggs of Fasciolopsis buski. The eggs measure 140 x 72.5 microm and are operculated. In this case, the patient did not present with symptoms suggestive of any intestinal parasitic infections. Detection of Fasciolopsis buski eggs in the stool was an incidental finding. She was diagnosed as a case of disseminated tuberculosis with fasciolopsiasis and was treated with antituberculosis drugs and praziquantel, respectively.
    Matched MeSH terms: Fasciolidae/isolation & purification*
  16. Lee WS, Hafeez A, Hassan H, Raja NS, Puthucheary SD
    PMID: 16124437
    A retrospective review of patients with focal non-typhoidal Salmonella (NTS) infection was performed to determine its features and outcome. All patients with focal NTS infection admitted to the University of Malaya Medical Center, Malaysia, from 1993 to 2002 were studied. More than half (58%) of the 35 cases (54% male, median age 39 years, range 1.5 months to 79 years) were immunocompromized or had chronic medical conditions. One-third of the patients (34%) had superficial infections (lymphadenitis or subcutaneous tissue infection) and all recovered with antimicrobial therapy alone. Deep infections (66%) noted were: meningitis (9%), osteomyelitis or arthritis (26%), abscesses of the gastrointestinal tract or adjacent organs (20%), and others (11%). Deep infections were more likely to occur in the extremes of age (<6 months or >60 years, p< 0.04), associated with adverse outcomes with an overall mortality rate of 9%, or required major surgery (15%).
    Matched MeSH terms: Salmonella/isolation & purification*
  17. Kamaliah MD, Bhajan MA, Dzarr GA
    PMID: 16124446
    We present an interesting and rare case of a diabetic patient who developed extensive unilateral emphysematous pyelonephritis (EPN) which was caused by fungal infection. The diagnosis was confirmed on computed tomography (CT) scan of the abdomen. Repeated urine cultures grew Candida albicans but no other organisms were isolated. The patient remained febrile and unwell despite parenteral broad spectrum antibiotics and antifungal treatment. She underwent nephrectomy and then made a good clinical recovery.
    Matched MeSH terms: Candida albicans/isolation & purification*
  18. Nissapatorn V, Kuppusamy I, Jamaiah I, Fong MY, Rohela M, Anuar AK
    PMID: 16438212
    This retrospective and descriptive study was a report on the clinical situation of tuberculosis in diabetic patients, with 1,651 patients recruited. The mean age of TBDM patients was significantly higher than that of non-diabetic patients (p<0.05). Moreover, TBDM patients had a higher ratio of male to female than the other group. The significant proportion of TB appeared to increase steadily with age in diabetic patients compared to non-diabetic ones (p<0.05). However, they showed similarities in terms of sex, race, marital status, present address, and occupation. A higher percentage of pulmonary tuberculosis (91.4%) was shown in the TBDM group. We found that both groups had no differences in the radiological findings, with opacity or cavity of the upper lobe involvement being 89% and 91% in TBDM and non-diabetic groups, respectively. TBDM patients were shown to have more treatment success (33.3%), particularly the pulmonary type of tuberculosis in the longer duration ( 9 months). Further findings demonstrated that a lower proportion of the TBDM group defaulted in their treatment (19.8%) and experienced resistance to anti-tubercular therapy (1.4%) compared to non-diabetics.
    Matched MeSH terms: Mycobacterium tuberculosis/isolation & purification*
  19. Lim PK, Looareesuwan S, Chindanond D, Saleh AM, Tan SK
    PMID: 10437950
    Matched MeSH terms: Plasmodium falciparum/isolation & purification
  20. Sagin DD, Ismail G, Fui JN, Jok JJ
    PMID: 11485090
    A serosurvey of various indigenous interior tribes (Orang Ulu) in upper Rejang River Basin Sarawak Malaysia, the site of a multibillion Ringgit hydroelectric power project, found 6.8% of the individual surveyed were seropositive for schistosomiasis, as determined by ELISA method using the soluble egg antigen of Schistosoma malayensis Baling strain. In all age group, the seroprevalence rate is higher (9.5%) in males than in females (4.5%) except for the 31-40 age group. Seroprevalence of schistosomiasis was found to increase with age with the above 60 age group having the highest rate followed by the 31-40 age group. Seroprevalence rate among the tribes ranges from 4.1% among the Penan to 11.6% among the Kajang. There was no seroevidence of schistosomiasis among the Ukits. A snail survey found four snail species including Brotia species, the intermediate host of the lung fluke Paragonimus westermani, however no schistosome snail host was identified. Although schistosomiasis malayensis-like infection may be endemic in the area, its public health significance remains undetermined.
    Matched MeSH terms: Schistosoma/isolation & purification
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