MyMedR

Fulltext Pathogenesis of Plasmodium berghei ANKA infection in the gerbil (Meriones unguiculatus) as an experimental model for severe malaria

Junaid QO, Khaw LT, Mahmud R, Ong KC, Lau YL, Borade PU, et al.

Parasite, 2017;24:38.

PMID: 29034874 DOI: 10.1051/parasite/2017040

BACKGROUND: As the quest to eradicate malaria continues, there remains a need to gain further understanding of the disease, particularly with regard to pathogenesis. This is facilitated, apart from in vitro and clinical studies, mainly via in vivo mouse model studies. However, there are few studies that have used gerbils (Meriones unguiculatus) as animal models. Thus, this study is aimed at characterizing the effects of Plasmodium berghei ANKA (PbA) infection in gerbils, as well as the underlying pathogenesis.

METHODS: Gerbils, 5-7 weeks old were infected by PbA via intraperitoneal injection of 1 × 106 (0.2 mL) infected red blood cells. Parasitemia, weight gain/loss, hemoglobin concentration, red blood cell count and body temperature changes in both control and infected groups were monitored over a duration of 13 days. RNA was extracted from the brain, spleen and whole blood to assess the immune response to PbA infection. Organs including the brain, spleen, heart, liver, kidneys and lungs were removed aseptically for histopathology.

RESULTS: Gerbils were susceptible to PbA infection, showing significant decreases in the hemoglobin concentration, RBC counts, body weights and body temperature, over the course of the infection. There were no neurological signs observed. Both pro-inflammatory (IFNγ and TNF) and anti-inflammatory (IL-10) cytokines were significantly elevated. Splenomegaly and hepatomegaly were also observed. PbA parasitized RBCs were observed in the organs, using routine light microscopy and in situ hybridization.

CONCLUSION: Gerbils may serve as a good model for severe malaria to further understand its pathogenesis.

Effect of Brugia pahangi co-infection with Plasmodium berghei ANKA in gerbils (Meriones unguiculatus)

Junaid OQ, Vythilingam I, Khaw LT, Sivanandam S, Mahmud R

Parasitol Res, 2020 Apr;119(4):1301-1315.

PMID: 32179986 DOI: 10.1007/s00436-020-06632-4

Malaria and lymphatic filariasis (LF) are two leading and common mosquito-borne parasitic diseases worldwide. These two diseases are co-endemic in many tropical and sub-tropical regions and are known to share vectors. The interactions between malaria and filarial parasites are poorly understood. Thus, this study aimed at establishing the interactions that occur between Brugia pahangi and Plasmodium berghei ANKA (PbA) co-infection in gerbils. Briefly, the gerbils were matched according to age, sex, and weight and grouped into filarial-only infection, PbA-only infection, co-infection, and control group. The parasitemia, survival and clinical assessment of the gerbils were monitored for a period of 30 days post Plasmodium infection. The immune responses of gerbils to both mono and co-infection were monitored. Findings show that co-infected gerbils have higher survival rate than PbA-infected gerbils. Food and water consumption were significantly reduced in both PbA-infected and co-infected gerbils, although loss of body weight, hypothermia, and anemia were less severe in co-infected gerbils. Plasmodium-infected gerbils also suffered hypoglycemia, which was not observed in co-infected gerbils. Furthermore, gerbil cytokine responses to co-infection were significantly higher than PbA-only-infected gerbils, which is being suggested as a factor for their increased longevity. Co-infected gerbils had significantly elicited interleukin-4, interferon-gamma, and tumor necrotic factor at early stage of infection than PbA-infected gerbils. Findings from this study suggest that B. pahangi infection protect against severe anemia and hypoglycemia, which are manifestations of PbA infection.

Randomized trial on the therapeutic equivalence between Eprex and GerEPO in patients on haemodialysis

Goh BL, Ong LM, Sivanandam S, Lim TO, Morad Z, Biogeneric EPO Study Group

Nephrology (Carlton), 2007 Oct;12(5):431-6.

PMID: 17803464

Treatment of renal anaemia with epoetin is well established. However, epoetin is expensive. Biogeneric epoetin with proven efficacy would reduce cost and improve access to therapy. We conducted this first ever comparative study of a biogeneric and the original product.

Protozoan and helminth parasites of small wild mammals in a new Felda settlement Jenderak Utara, Central Pahang, Peninsular Malaysia

Fong YL, Liat LB, de Witt GF, Krishnasamy M, Sivanandam S, Foong PY

Southeast Asian J. Trop. Med. Public Health, 1977 Sep;8(3):345-53.

PMID: 415370

Filariasis blood survey in Kelantan

Dondero TJ, Sivanandam S

Med J Malaysia, 1973 Jun;27(4):306-9.

PMID: 4270791

Diurnally sub-periodic microfilarial pattern in Brugia malayi in West Malaysia

Dondero TJ, Sivanandam S

Trans R Soc Trop Med Hyg, 1971;65(5):691-3.

PMID: 5159155

Filariasis in Negri Sembilan--a follow-up study

Cheah WC, Cheong WH, Mahadevan S, Lai KP, Sivanandam S

Med J Malaysia, 1977 Dec;32(2):103-10.

PMID: 614475

Fulltext Stress exacerbates infectivity and pathogenicity of Blastocystis hominis: in vitro and in vivo evidences

Chandramathi S, Suresh K, Sivanandam S, Kuppusamy UR

PLoS One, 2014;9(5):e94567.

PMID: 24788756 DOI: 10.1371/journal.pone.0094567

Stress alters the oxidant-antioxidant state and immune cell responses which disrupts its function to combat infection. Blastocystis hominis, a common intestinal protozoan has been reported to be opportunistic in immunocompromised patients namely cancer. B. hominis infectivity in other altered immune system conditions especially stress is unknown. We aimed to demonstrate the stress effects towards the susceptibility and pathogenicity of B. hominis infection.

Fulltext Prevalence of filarial parasites in domestic and stray cats in Selangor State, Malaysia

Al-Abd NM, Nor ZM, Kassim M, Mansor M, Al-Adhroey AH, Ngui R, et al.

Asian Pac J Trop Med, 2015 Sep;8(9):705-9.

PMID: 26433654 DOI: 10.1016/j.apjtm.2015.07.034

OBJECTIVE: To determine the prevalence of the filarial parasites,ie.,Brugia malayi, Brugia, Brugia pahangi(B. pahangi), Dirofilaria immitisandDirofilaria repens (D. repens) in domestic and stray cats.

METHODS: A total of 170 blood sample were collected from domestic and stray cats and examined for filarial worm parasites in two localities, Pulau Carey and Bukit Gasing, Selangor State, Malaysia.

RESULTS: The overall prevalence of infection was 23.5% (40/170; 95% CI = 17.4-30.6). Of this, 35% (14/40; 95% CI = 22.1-50.5) and 50% (20/40; 95% CI = 35.2-64.8) were positive for single B. pahangi nd D. repens, respectively. The remaining of 15% (6/40; 95% CI = 7.1-29.1) were positive for mixed B. pahangi and D. repens. In addition, 75% of the infected cats were domestic, and 25% were strays. No Brugia malayi and Dirofilaria immitis was detected. Eighty-four cats were captured at Pulau Carey, of which 35.7% (30/84) were infected. Among the cats determined to be infected, 93% (28/30; 95% CI = 78.7-98.2) were domestic, and only 6.7% (2/30; 95% CI = 19.0-21.3) were strays. Conversely, the number of infected cats was three times lower in Bukit Gasing than in Pulau Carey, and most of the cats were stray.

CONCLUSIONS: B. pahangi and D. repens could be the major parasites underlying filariasis in the study area. Adequate prophylactic plans should be administrated in the cat population in study area.

Fulltext Recent advances on the use of biochemical extracts as filaricidal agents

Al-Abd NM, Nor ZM, Al-Adhroey AH, Suhaimi A, Sivanandam S

Evid Based Complement Alternat Med, 2013;2013:986573.

PMID: 24298292 DOI: 10.1155/2013/986573

Lymphatic filariasis is a parasitic infection that causes a devastating public health and socioeconomic burden with an estimated infection of over 120 million individuals worldwide. The infection is caused by three closely related nematode parasites, namely, Wuchereria bancrofti, Brugia malayi, and B. timori, which are transmitted to human through mosquitoes of Anopheles, Culex, and Aedes genera. The species have many ecological variants and are diversified in terms of their genetic fingerprint. The rapid spread of the disease and the genetic diversification cause the lymphatic filarial parasites to respond differently to diagnostic and therapeutic interventions. This in turn prompts the current challenge encountered in its management. Furthermore, most of the chemical medications used are characterized by adverse side effects. These complications urgently warrant intense prospecting on bio-chemicals that have potent efficacy against either the filarial worms or thier vector. In lieu of this, we presented a review on recent literature that reported the efficacy of filaricidal biochemicals and those employed as vector control agents. In addition, methods used for biochemical extraction, screening procedures, and structure of the bioactive compounds were also presented.

Fulltext Modified Field stain - rapid viability test for Trichomonas vaginalis

Afzan MY, Sivanandam S, Suresh K

J Appl Microbiol, 2012 Jan;112(1):132-7.

PMID: 22040369 DOI: 10.1111/j.1365-2672.2011.05185.x

We previously reported that Modified Field Stain (MF) can be used as a rapid stain for diagnosis. In the present study we extend the observation to include the stain as an alternative method to assess viability of the cells.

Modified Field's staining--a rapid stain for Trichomonas vaginalis

Afzan MY, Sivanandam S, Kumar GS

Diagn Microbiol Infect Dis, 2010 Oct;68(2):159-62.

PMID: 20846588 DOI: 10.1016/j.diagmicrobio.2010.06.005

Trichomonas vaginalis, a flagellate protozoan parasite commonly found in the human genitourinary tract, is transmitted primarily by sexual intercourse. Diagnosis is usually by in vitro culture method and staining with Giemsa stain. There are laboratories that use Gram stain as well. We compared the use of modified Field's (MF), Giemsa, and Gram stains on 2 axenic and xenic isolates of T. vaginalis, respectively. Three smears from every sediment of spun cultures of all 4 isolates were stained, respectively, with each of the stains. We showed that MF staining, apart from being a rapid stain (20 s), confers sharper staining contrast, which differentiates the nucleus and the cytoplasm of the organism when compared to Giemsa and Gram staining especially on parasites from spiked urine samples. The alternative staining procedure offers in a diagnostic setting a rapid stain that can easily visualize the parasite with sharp contrasting characteristics between organelles especially the nucleus and cytoplasm. Vacuoles are more clearly visible in parasites stained with MF than when stained with Giemsa.

Displaying publications 21 - 32 of 32 in total