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Copro-molecular study of Entamoeba infection among the indigenous community in Malaysia: A first report on the species-specific prevalence of Entamoeba in dogs

Ngui R, Hassan NA, Nordin NMS, Mohd-Shaharuddin N, Chang LY, Teh CSJ, et al.

Acta Trop, 2020 Apr;204:105334.
PMID: 31926914 DOI: 10.1016/j.actatropica.2020.105334

BACKGROUND: Entamoeba is a free-living protozoan parasitic species that infect a variety of hosts. In humans, Entamoeba histolytica is the causative agent of amoebiasis. Entamoeba species has also been reported in dogs. However, little is known about the molecular epidemiology and the specific species of this parasite in dogs globally, including Malaysia. As dogs are important companion animals for the indigenous community, and close contact with dogs is part of the natural living conditions for this community, this study aims to determine the prevalence and molecular epidemiology of Entamoeba species in human and dogs in Malaysia.
METHOD: The presence of Entamoeba species was examined in 504 fresh fecal samples, collected randomly from 411 humans and 93 dogs using microscopy and polymerase chain reaction (PCR) amplifying 16 s ribosomal RNA (rRNA). Data was analyzed using appropriate statistical analysis.
RESULTS: The microscopy data showed an overall occurrence of Entamoeba species of 26.3% (108/411) and 36.6% (34/93) in humans and dogs respectively. In humans, the most common species was a single infection of E. dispar (26.5%; 13/49), followed by E. histolytica and E. moshkovskii, (20.4% for each species respectively). Double infection of E. dispar + E. moshkovskii was detected at 10.2%, followed by E. dispar + E. histolytica (8.2%) and E. moshkovskii and E. histolytica (6.1%). 8.2% of the samples had triple infection with all three species. In animals, E. moshkovskii (46.7%) was the most common species detected, followed by E. histolytica, and E. dispar, at 20.0% and 13.3% respectively. Double infection with E. moshkovskii + E. histolytica and a triple infection were found in 2 samples (13.3%) and 1 (6.7%) sample respectively. Risk factor analysis showed that members of the community who used untreated water were more prone to be infected with Entamoeba.
CONCLUSION: This study provides information on the species-specific occurrence of Entamoeba infection, the potential risk factors and their zoonotic potential to humans. This is the first report to describe the molecular occurrence of Entamoeba species in dogs in Malaysia. The presence of pathogenic Entamoeba species implies that dogs could be a reservoir or mechanical host for human amoebiasis. Further studies need to be conducted to better understand the transmission dynamics and public health significance of Entamoeba species in human and animal hosts.
Fulltext Plant-derived chimeric antibodies inhibit the invasion of human fibroblasts by Toxoplasma gondii

Lim SSY, Chua KH, Nölke G, Spiegel H, Goh WL, Chow SC, et al.

PeerJ, 2018;6:e5780.
PMID: 30581655 DOI: 10.7717/peerj.5780

The parasite Toxoplasma gondii causes an opportunistic infection, that is, particularly severe in immunocompromised patients, infants, and neonates. Current antiparasitic drugs are teratogenic and cause hypersensitivity-based toxic side effects especially during prolonged treatment. Furthermore, the recent emergence of drug-resistant toxoplasmosis has reduced the therapeutic impact of such drugs. In an effort to develop recombinant antibodies as a therapeutic alternative, a panel of affinity-matured, T. gondii tachyzoite-specific single-chain variable fragment (scFv) antibodies was selected by phage display and bioinformatic analysis. Further affinity optimization was attempted by introducing point mutations at hotspots within light chain complementarity-determining region 2. This strategy yielded four mutated scFv sequences and a parental scFv that were used to produce five mouse-human chimeric IgGs in Nicotiana benthamiana plants, with yields of 33-72 mg/kg of plant tissue. Immunological analysis confirmed the specific binding of these plant-derived antibodies to T. gondii tachyzoites, and in vitro efficacy was demonstrated by their ability to inhibit the invasion of human fibroblasts and impair parasite infectivity. These novel recombinant antibodies could therefore be suitable for the development of plant-derived immunotherapeutic interventions against toxoplasmosis.
Fulltext Implementing HLA-B*58:01 testing prior to allopurinol initiation in Malaysian primary care setting: A qualitative study from doctors' and patients' perspective

Ng WL, Hussein N, Ng CJ, Qureshi N, Lee YK, Kwan Z, et al.

PLoS One, 2024;19(1):e0296498.
PMID: 38206925 DOI: 10.1371/journal.pone.0296498

INTRODUCTION: Allopurinol, the first-line treatment for chronic gout, is a common causative drug for severe cutaneous adverse reactions (SCAR). HLA-B*58:01 allele was strongly associated with allopurinol-induced SCAR in Asian countries such as Taiwan, Japan, Thailand and Malaysia. HLA-B*58:01 screening before allopurinol initiation is conditionally recommended in the Southeast-Asian population, but the uptake of this screening is slow in primary care settings, including Malaysia. This study aimed to explore the views and experiences of primary care doctors and patients with gout on implementing HLA-B*58:01 testing in Malaysia as part of a more extensive study exploring the feasibility of implementing it routinely.
METHODS: This qualitative study used in-depth interviews and focus group discussions to obtain information from patients with gout under follow-up in primary care and doctors who cared for them. Patients and doctors shared their gout management experiences and views on implementing HLA-B*58:01 screening in primary care. Data were coded and analysed using thematic analysis.
RESULTS: 18 patients and 18 doctors from three different healthcare settings (university hospital, public health clinics, private general practitioner clinics) participated. The acceptability to HLA-B*58:01 screening was good among the doctors and patients. We discovered inadequate disclosure of severe side effects of allopurinol by doctors due to concerns about medication refusal by patients, which could potentially be improved by introducing HLA-B*58:01 testing. Barriers to implementation included out-of-pocket costs for patients, the cost-effectiveness of this implementation, lack of established alternative treatment pathway besides allopurinol, counselling burden and concern about genetic data security. Our participants preferred targeted screening for high-risk populations instead of universal screening.
CONCLUSION: Implementing HLA-B*58:01 testing in primary care is potentially feasible if a cost-effective, targeted screening policy on high-risk groups can be developed. A clear treatment pathway for patients who test positive should be made available.
Fulltext Serotypes & penicillin susceptibility of Streptococcus pneumoniae isolated from children admitted to a tertiary teaching hospital in Malaysia

Subramaniam P, Jabar KA, Kee BP, Chong CW, Nathan AM, de Bruyne J, et al.

Indian J Med Res, 2018 Aug;148(2):225-231.
PMID: 30381546 DOI: 10.4103/ijmr.IJMR_1987_16

Background & objectives: Streptococcus pneumoniae: (pneumococcus) is a highly invasive extracellular pathogen that causes diseases such as pneumonia, otitis media and meningitis. This study was undertaken to determine the serotype diversity and penicillin susceptibility of S. pneumoniae isolated from paediatric patients in a tertiary teaching hospital in Malaysia.
Methods: A total of 125 clinical isolates collected from January 2013 to May 2015 were serotyped using seven sequential multiplex polymerase chain reactions. The susceptibility of these isolates to penicillin was also investigated.
Results: Serotypes detected among the isolates were serotypes 3, 6A/B, 6C, 11/A/D/F, 15A/F, 19A, 19F, 23A, 23F, 34. Serotypes 19F and 6A/B were the most prevalent serotypes detected. Most of the S. pneumoniae were isolated from nasopharyngeal samples of children below five years of age. Majority of the isolates were penicillin susceptible. Only 5.6 per cent of the isolates were non-susceptible to penicillin, mostly of serotype 19F.
Interpretation & conclusions: Our study revealed the distribution of various serotypes in S. pneumoniae isolates obtained from children in a teaching hospital at Kuala Lumpur, Malaysia and decreasing rates of penicillin resistance among them. The shifts in serotypes and susceptibility to penicillin from time to time have been observed. Continuous monitoring and surveillance are pivotal for better infection control and management of pneumococcal infections among children.