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Hamatopeduncularia Yamaguti, 1953 (Monogenea: Ancylodiscoididae) from catfish off Peninsular Malaysia: Description of two new species and insights on the genus

Soo OYM, Tan WB

Parasitol Int, 2021 Apr;81:102282.
PMID: 33444771 DOI: 10.1016/j.parint.2021.102282

Hamatopeduncularia longiangusticirrata sp. nov. and H. petalumvaginata sp. nov. were collected from Arius maculatus and Nemapteryx caelata, respectively from Tanjung Karang, Peninsular Malaysia. Morphological and molecular investigations were carried out to ascertain the identity of the new species. The two new species differ from previously described Hamatopeduncularia species in the morphology of the male and female reproductive organs. Hamatopeduncularia longiangusticirrata sp. nov. possesses a long penis similar to H. elongata, H. longicopulatrix, H. brisbanensis, H. major and H. petalumvaginata sp. nov., but differs in having a thread-like tapering distal end and can be distinguished from H. brisbanensis and H. major in not having an accessory piece. Hamatopeduncularia longiangusticirrata sp. nov. is also unique in having an ornamented penis initial and a vaginal tube surrounded by fine hair-like structures. Hamatopeduncularia petalumvaginata sp. nov. possesses a simple penis without an accessory piece and a petaloid vaginal opening that resembles the arrangement of petals on a flower. Maximum likelihood trees were constructed from partial 28S and 18S rDNA sequences of the two new species and other ancylodiscoidids to reveal a strongly supported monophyletic branch consisting of the two new species for both markers. According to Lim's classification in 1996 of Hamatopeduncularia species penis type, H. petalumvaginata sp. nov. has been classified within the elegans-type and H. longiangusticirrata sp. nov. is proposed as the longiangusticirrata-type.

Matched MeSH terms: RNA, Ribosomal, 18S/analysis
Fulltext Monitoring of Waterborne Parasites in Two Drinking Water Treatment Plants: A Study in Sarawak, Malaysia

Richard RL, Ithoi I, Abd Majid MA, Wan Sulaiman WY, Tan TC, Nissapatorn V, et al.

Int J Environ Res Public Health, 2016 06 28;13(7).
PMID: 27367710 DOI: 10.3390/ijerph13070641

The occurrence of waterborne parasites coupled with water parameters at various processing sites of two drinking water treatment plants (A and B) and seven distribution system (DS) sites in Sarawak, Malaysia were studied. Ten liters of water underwent immunomagnetic separation (IMS) technique to detect the presence of Giardia and Cryptosporidium (oo)cysts. The remaining supernatant was used to detect other parasites whilst 50 mL of water sample was each used in the detection of free-living amoebae and fecal coliforms. Sampled water was positive for Giardia (32.9%; 28/85), Cryptosporidium (18.8%; 16/85) followed by Spirometra ova-like (25.9%; 22/85), Blastocystis-like (25.9%; 22/85), nematode larvae-like (8.2%; 7/85) and Taenia ova-like (1.2%; 1/85). Meanwhile, 90.2% (55/61) samples were positive for Acanthamoeba and Naegleria via cultivation and of these, 11 isolates were confirmed as Acanthamoeba genotype T3 (5/7) and T4 (2/7) followed by Naegleria sp. (4/11), Naegleria italica (2/11), Naegleria australiensis (1/11), Naegleria angularis (1/11) and Vahlkampfia sp. (3/11). Cryptosporidium, Acanthamoeba and Naegleria were also detected in one of the seven tested DS sites. Only Giardia and Cryptosporidium showed significant correlations with fluoride and fecal coliforms. These results describe the occurrence of waterborne parasites that will assist key stakeholders in mitigating contamination at the specific sites.

Matched MeSH terms: RNA, Ribosomal, 18S/analysis
Fulltext Validation of SYBR green I based closed-tube loop-mediated isothermal amplification (LAMP) assay for diagnosis of knowlesi malaria

Lai MY, Ooi CH, Lau YL

Malar J, 2021 Mar 25;20(1):166.
PMID: 33766038 DOI: 10.1186/s12936-021-03707-0

BACKGROUND: As an alternative to PCR methods, LAMP is increasingly being used in the field of molecular diagnostics. Under isothermal conditions at 65 °C, the entire procedure takes approximately 30 min to complete. In this study, we establish a sensitive and visualized LAMP method in a closed-tube system for the detection of Plasmodium knowlesi.
METHODS: A total of 71 malaria microscopy positive blood samples collected in blood spots were obtained from the Sarawak State Health Department. Using 18s rRNA as the target gene, nested PCR and SYBR green I LAMP assay were performed following the DNA extraction. The colour changes of LAMP end products were observed by naked eyes.
RESULTS: LAMP assay demonstrated a detection limit of 10 copies/µL in comparison with 100 copies/µL nested PCR. Of 71 P. knowlesi blood samples collected, LAMP detected 69 microscopy-positive samples. LAMP exhibited higher sensitivity than nested PCR assay. The SYBR green I LAMP assay was 97.1% sensitive (95% CI 90.2-99.7%) and 100% specific (95% CI 83.2-100%). Without opening the cap, incorporation of SYBR green I into the inner cap of the tube enabled the direct visualization of results upon completion of amplification. The positives instantaneously turned green while the negatives remained orange.
CONCLUSIONS: These results indicate that SYBR green I LAMP assay is a convenient diagnosis tool for the detection of P. knowlesi in remote settings.

Matched MeSH terms: RNA, Ribosomal, 18S/analysis
Emergence of Aureobasidium pullulans as human fungal pathogen and molecular assay for future medical diagnosis

Chan GF, Puad MS, Chin CF, Rashid NA

Folia Microbiol (Praha), 2011 Sep;56(5):459-67.
PMID: 21909832 DOI: 10.1007/s12223-011-0070-9

Despite the great importance of Aureobasidium pullulans in biotechnology, the fungus had emerged as an opportunistic human pathogen, especially among immunocompromised patients. Clinical detection of this rare human fungal pathogen presently relies on morphology diagnosis which may be misleading. Thus, a sensitive and accurate quantitative molecular assay for A. pullulans remains lacking. In this study, we presented the microscopy observations of A. pullulans that reveals the phenotypic plasticity of the fungus. A. pullulans-specific primers and molecular beacon probes were designed based on the fungal 18S ribosomal RNA (rRNA) gene. Comparison of two probes with varied quencher chemistry, namely BHQ-1 and Tamra, revealed high amplification efficiency of 104% and 108%, respectively. The optimized quantitative real-time PCR (qPCR) assays could detect and quantify up to 1 pg concentration of A. pullulans DNA. Both assays displayed satisfactory performance parameters at fast thermal cycling mode. The molecular assay has great potential as a molecular diagnosis tool for early detection of fungal infection caused by A. pullulans, which merits future study in clinical diagnosis.

Matched MeSH terms: RNA, Ribosomal, 18S/analysis