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Fulltext Resource partitioning among bat species in Peninsular Malaysia rice fields

Abdullah NI, Elias NA, Ohte N, Vincenot C

PeerJ, 2024;12:e16657.
PMID: 38250723 DOI: 10.7717/peerj.16657

Resource partitioning among tropical bats in agricultural areas of Peninsular Malaysia remains unclear. This study was conducted to evaluate resource partitioning among bats by examining their fecal samples. The main bat species sampled included: Rhinolophus coelophyllus, Rhinolophus malayanus, Rhinolophus pusillus, Rhinolophus refulgens, Taphozous melanopogon and Hipposideros larvatus. Two harp traps were set at different elevations on a hilltop (Gunung Keriang) and two high nets were used in neighboring rice fields at three sites, for three consecutive nights per sampling from April 2021 to February 2022. A total of 301 bats and 1,505 pellets were analyzed using a conventional approach which examined the fecal sample under the microscope. All of the bat species within the study had insects from the order Coleoptera, Lepidoptera, Diptera and Hemiptera in their diet. Larger bats exhibited a greater variety of prey consumption. Male individuals were observed to be generalists while female individuals were specialists, particularly during pregnancy and lactating reproductive stages. Bat species and insect order had a significant impact on the percentage fragment frequency of the insects consumed. Rhinolophus coelophyllus specialized in feeding on Coleoptera and Diptera, H. larvatus fed on Coleoptera, R. malayanus fed on Hemiptera, R. pusillus and T. melanopogon fed on Lepidoptera. Future molecular analysis can be carried out to further identify the insect pests consumed by these bats up to species level. These findings enhance our understanding of bats' ecological roles in agricultural landscapes and contribute to conservation and pest management strategies.
Fulltext Colonization of Methicillin-Resistant Staphylococcus aureus (MRSA) among Medical Students in Tertiary Institution in Central Malaysia

Rampal S, Zainuddin NH, Elias NA, Tengku Jamaluddin TZM, Maniam S, Teh SW, et al.

Antibiotics (Basel), 2020 Jul 06;9(7).
PMID: 32640588 DOI: 10.3390/antibiotics9070382

Methicillin-resistant Staphylococcus aureus or MRSA infection is virulent and presents with a broad spectrum of severity. Limited regional reports that specifically outlined the potential risk of medical students being part of the dissemination of MRSA in healthcare settings were noted. This study aims to assess the prevalence and contributory factors of colonization of MRSA on neckties, headscarves, and ID badges among medical students in a local medical university in Malaysia. A cross-sectional study was conducted involving 256 medical students. A validated questionnaire was used to collect the data, and sample swabs were collected between July and August 2013 by swabbing neckties, headscarves, or identification badges. The swabs were then streaked onto mannitol salt agar (MSA) and incubated at 37 °C overnight. Out of 433 samples taken, 40 swabs (9.24%) were positive for Staphylococcus aureus. Out of the 40 swabs, five (12.5%) isolates were MRSA (one culture was isolated from the headscarf of a preclinical student, one culture was isolated from the necktie of clinical students, while the remaining three were isolated from identification badges of clinical students. There was no significant association between age, gender, ethnicity, and phase of medical students with the colonization of MRSA (p > 0.05). There was a significant association between knowledge score on hand hygiene practice and phase of medical students. MRSA colonies were present on neckties, headscarves, and identification badges of medical students of all phases. The findings from this study suggest the need for improvement of hand hygiene knowledge and discontinuity of mandatory use of physical ID badges and neckties among medical students.
Fulltext Polychaeta-mediated synthesis of gold nanoparticles: A potential antibacterial agent against Acute Hepatopancreatic Necrosis Disease (AHPND)-causing bacteria, Vibrio parahaemolyticus

Abu Hassan MS, Elias NA, Hassan M, Rahmah S, Wan Ismail WI, Harun NA

Heliyon, 2023 Nov;9(11):e21663.
PMID: 37954386 DOI: 10.1016/j.heliyon.2023.e21663

Gold nanoparticles (AuNPs) have emerged as a promising application in aquaculture. Their nano-sized dimensions, comparable to pathogens offer potential solutions for combating antibiotic resistance. In this study, AuNPs were synthesized by using polychaetes, Marphysa moribidii as the bio-reducing agent. Modifications were made to reduce agglomeration in green-synthesized AuNPs through ultrasonication. The antibacterial activities of AuNPs against V. parahaemolyticus were evaluated. The physicochemical characteristics of the green synthesized AuNPs were comprehensively investigated. The successful formation of AuNPs was confirmed by the appearance of a red ruby colour and the presence of surface Plasmon resonance (SPR) absorption peaks at 530 nm as observed from UV-vis spectroscopy. Scanning electron microscopy (SEM) revealed spherical-shaped AuNPs with some agglomerations. Transmission electron microscopy (TEM) showed particle size of AuNPs ranging from 10 nm to 60 nm, meanwhile dynamic light scattering (DLS) analysis indicated an average particle size of 24.36 nm. X-ray diffraction (XRD) analysis confirmed the high crystallinity of AuNPs, and no AuNPs were detected in the polychaetes extracts prior to synthesis. A brief ultrasonication significantly reduced the tendencies for AuNPs to coalesce. The green-synthesized AuNPs demonstrated a remarkable antibacterial efficacy against V. parahaemolyticus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests revealed that a concentration of 0.3 g/ml of AuNPs effectively inhibited V. parahaemolyticus. These findings highlighted the potential of green-synthesized AuNPs as antibacterial agents for the prevention and management of AHPND in aquaculture.
Clinicopathological correlation of oral candidiasis - Our experience in a tertiary centre over two decades

Tan CC, Lim D, Mohd Hisham NQ, Elias NA, Azli AS, Goh YC

Malays J Pathol, 2023 Aug;45(2):237-246.
PMID: 37658533

INTRODUCTION: Oral candidiasis is one of the most common fungal infections that has been widely reported around the world. In Malaysia, the available studies for this infection are scarce.
MATERIALS AND METHODS: This is a 20-year retrospective study aimed to investigate the prevalence, demographic characteristics, clinical presentations, and the association of oral candidiasis with clinical parameters in oral candidiasis cases reported in the Faculty of Dentistry, Universiti Malaya from 1999 until 2019. A total of 12,964 histopathological records from the Oral Pathology Diagnostic and Research Laboratory (OPDRL) between 1999 to 2019 were retrieved. Oral candidiasis cases were selected according to the inclusion and exclusion criteria. Information of interest was obtained and analysed.
RESULTS: From the total records retrieved, 378 oral candidiasis cases were recorded and 82.8% were diagnosed from smear test. This study showed that oral candidiasis was predominantly reported in female (64.2%) and Indian population (64.2%). The peak incidence was in the sixth decades of life (27.0%). The most commonly affected site was tongue and coated tongue was the most common clinical presentation. More than 50% of the cases had comorbidity and 10.6% were associated with dentures. Ethnicity and site of occurrence were significantly associated (p<0.05) with oral candidiasis.
CONCLUSION: This is the first large-scale study of oral candidiasis cases in Malaysia. The findings of this study are useful for clinical assessment of patients suspected of oral candidiasis.
Fulltext Perigone Lobe Transcriptome Analysis Provides Insights into Rafflesia cantleyi Flower Development

Lee XW, Mat-Isa MN, Mohd-Elias NA, Aizat-Juhari MA, Goh HH, Dear PH, et al.

PLoS One, 2016;11(12):e0167958.
PMID: 27977777 DOI: 10.1371/journal.pone.0167958

Rafflesia is a biologically enigmatic species that is very rare in occurrence and possesses an extraordinary morphology. This parasitic plant produces a gigantic flower up to one metre in diameter with no leaves, stem or roots. However, little is known about the floral biology of this species especially at the molecular level. In an effort to address this issue, we have generated and characterised the transcriptome of the Rafflesia cantleyi flower, and performed a comparison with the transcriptome of its floral bud to predict genes that are expressed and regulated during flower development. Approximately 40 million sequencing reads were generated and assembled de novo into 18,053 transcripts with an average length of 641 bp. Of these, more than 79% of the transcripts had significant matches to annotated sequences in the public protein database. A total of 11,756 and 7,891 transcripts were assigned to Gene Ontology categories and clusters of orthologous groups respectively. In addition, 6,019 transcripts could be mapped to 129 pathways in Kyoto Encyclopaedia of Genes and Genomes Pathway database. Digital abundance analysis identified 52 transcripts with very high expression in the flower transcriptome of R. cantleyi. Subsequently, analysis of differential expression between developing flower and the floral bud revealed a set of 105 transcripts with potential role in flower development. Our work presents a deep transcriptome resource analysis for the developing flower of R. cantleyi. Genes potentially involved in the growth and development of the R. cantleyi flower were identified and provide insights into biological processes that occur during flower development.
Fulltext Transcriptome analysis of Rafflesia cantleyi flower stages reveals insights into the regulation of senescence

Mohd-Elias NA, Rosli K, Alias H, Juhari MA, Abu-Bakar MF, Md-Isa N, et al.

Sci Rep, 2021 Dec 08;11(1):23661.
PMID: 34880337 DOI: 10.1038/s41598-021-03028-x

Rafflesia is a unique plant species existing as a single flower and produces the largest flower in the world. While Rafflesia buds take up to 21 months to develop, its flowers bloom and wither within about a week. In this study, transcriptome analysis was carried out to shed light on the molecular mechanism of senescence in Rafflesia. A total of 53.3 million high quality reads were obtained from two Rafflesia cantleyi flower developmental stages and assembled to generate 64,152 unigenes. Analysis of this dataset showed that 5,166 unigenes were differentially expressed, in which 1,073 unigenes were identified as genes involved in flower senescence. Results revealed that as the flowers progress to senescence, more genes related to flower senescence were significantly over-represented compared to those related to plant growth and development. Senescence of the R. cantleyi flower activates senescence-associated genes in the transcription activity (members of the transcription factor families MYB, bHLH, NAC, and WRKY), nutrient remobilization (autophagy-related protein and transporter genes), and redox regulation (CATALASE). Most of the senescence-related genes were found to be differentially regulated, perhaps for the fine-tuning of various responses in the senescing R. cantleyi flower. Additionally, pathway analysis showed the activation of genes such as ETHYLENE RECEPTOR, ETHYLENE-INSENSITIVE 2, ETHYLENE-INSENSITIVE 3, and ETHYLENE-RESPONSIVE TRANSCRIPTION FACTOR, indicating the possible involvement of the ethylene hormone response pathway in the regulation of R. cantleyi senescence. Our results provide a model of the molecular mechanism underlying R. cantleyi flower senescence, and contribute essential information towards further understanding the biology of the Rafflesiaceae family.
Fulltext ChiroVox: a public library of bat calls

Görföl T, Huang JC, Csorba G, Győrössy D, Estók P, Kingston T, et al.

PeerJ, 2022;10:e12445.
PMID: 35070499 DOI: 10.7717/peerj.12445

Recordings of bat echolocation and social calls are used for many research purposes from ecological studies to taxonomy. Effective use of these relies on identification of species from the recordings, but comparative recordings or detailed call descriptions to support identification are often lacking for areas with high biodiversity. The ChiroVox website (https://www.chirovox.org) was created to facilitate the sharing of bat sound recordings together with their metadata, including biodiversity data and recording circumstances. To date, more than 30 researchers have contributed over 3,900 recordings of nearly 200 species, making ChiroVox the largest open-access bat call library currently available. Each recording has a unique identifier that can be cited in publications; hence the acoustic analyses are repeatable. Most of the recordings available through the website are from bats whose species identities are confirmed, so they can be used to determine species in recordings where the bats were not captured or could not be identified. We hope that with the help of the bat researcher community, the website will grow rapidly and will serve as a solid source for bat acoustic research and monitoring.