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1.
J Water Health ; 20(1): 54-67, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35100154

RESUMEN

The present study identifies the Acanthamoeba genotypes and their pathogenic potential in five marine waters in Malaysia. Fifty water samples were collected between January and May 2019. Physical parameters of water quality were measured in situ, whereas chemical and microbiological analyses were conducted in the laboratory. All samples had undergone filtration using nitrocellulose membrane and were tested for Acanthamoeba using cultivation and polymerase chain reaction by targeting the 18S ribosomal RNA gene. The pathogenic potential of all positive isolates was identified using physiological tolerance tests. Thirty-six (72.0%) samples were positive for Acanthamoeba. Total coliforms (p = 0.013) and pH level (p = 0.023) displayed significant correlation with Acanthamoeba presence. Phylogenetic analysis showed that 27 samples belonged to genotype T4, four (T11), two (T18) and one from each genotype T5, T15 and T20. Thermo- and osmo-tolerance tests signified that three (8.3%) Acanthamoeba strains displayed highly pathogenic attributes. This study is the first investigation in Malaysia describing Acanthamoeba detection in marine water with molecular techniques and genotyping. The study outcomes revealed that the marine water in Malaysia could be an integral source of Acanthamoeba strains potentially pathogenic in humans. Thus, the potential risk of this water should be monitored routinely in each region.


Asunto(s)
Acanthamoeba , Acanthamoeba/genética , Genotipo , Humanos , Malasia , Filogenia , ARN Ribosómico 18S/genética
2.
Int Microbiol ; 24(3): 363-371, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33754231

RESUMEN

Acanthamoeba keratitis is a sight-endangering eye infection, and causative organism Acanthamoeba presents a significant concern to public health, given escalation of contact lens wearers. Contemporary therapy is burdensome, necessitating prompt diagnosis and aggressive treatment. None of the contact lens disinfectants (local and international) can eradicate Acanthamoeba effectively. Using a range of compounds targeting cellulose, ion channels, and biochemical pathways, we employed bioassay-guided testing to determine their anti-amoebic effects. The results indicated that acarbose, indaziflam, terbuthylazine, glimepiride, inositol, vildagliptin and repaglinide showed anti-amoebic effects. Compounds showed minimal toxicity on human cells. Therefore, effects of the evaluated compounds after conjugation with nanoparticles should certainly be the subject of future studies and will likely lead to promising leads for potential applications.


Asunto(s)
Queratitis por Acanthamoeba/tratamiento farmacológico , Queratitis por Acanthamoeba/parasitología , Acanthamoeba castellanii/efectos de los fármacos , Antiprotozoarios/farmacología , Lentes de Contacto/parasitología , Acarbosa/farmacología , Carbamatos/farmacología , Línea Celular , Soluciones para Lentes de Contacto/farmacología , Lentes de Contacto/efectos adversos , Células HaCaT , Humanos , Indenos/farmacología , Inositol/farmacología , Nanopartículas , Piperidinas/farmacología , Compuestos de Sulfonilurea/farmacología , Triazinas/farmacología , Vildagliptina/farmacología
3.
Molecules ; 26(16)2021 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-34443585

RESUMEN

Crocodiles are remarkable animals that have the ability to endure extremely harsh conditions and can survive up to a 100 years while being exposed to noxious agents that are detrimental to Homo sapiens. Besides their immunity, we postulate that the microbial gut flora of crocodiles may produce substances with protective effects. In this study, we isolated and characterized selected bacteria colonizing the gastrointestinal tract of Crocodylusporosus and demonstrated their inhibitory effects against three different cancerous cell lineages. Using liquid chromatography-mass spectrometry, several molecules were identified. For the first time, we report partial analyses of crocodile's gut bacterial molecules.


Asunto(s)
Caimanes y Cocodrilos/microbiología , Bacterias/aislamiento & purificación , Microbioma Gastrointestinal , Animales , Bacterias/metabolismo , Línea Celular Tumoral
4.
Malays J Med Sci ; 27(2): 151-158, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32788850

RESUMEN

BACKGROUND: Mobile phones (MPs) have become one of the most indispensable accessories in social and professional life. Though they offer plenty of benefits, MPs are prolific breeding grounds for infectious pathogens in communities. Thus, the aim of this study was to identify the prevalence of bacterial contamination and determine antimicrobial susceptibility pattern of Staphylococcus aureus (S. aureus) from MPs. METHODS: A cross-sectional study was conducted from March to July 2019 on 126 students and 37 laboratory staff/clinical instructors' MPs from the Faculty of Health Sciences, Universiti Teknologi MARA, Malaysia by a simple random sampling technique. Along with the questionnaire, a swab sample from each participant's MPs was collected and transported to the microbiology laboratory for bacterial culture as per standard microbiological procedures and antimicrobial susceptibility test by the disc diffusion technique. Data were analysed by the Statistical Package for Social Sciences Programme version 24. RESULTS: All of the tested MPs were contaminated with either single or mix bacterial agents. Bacillus spp. (74.8%), coagulase-negative staphylococci (CoNS; 47.9%) and S. aureus (20.9%) were the most predominant bacterial isolates, whilst the least isolate was Proteus vulgaris (P. vulgaris) (2.5%). Oxacillin resistance was seen in 5.9% of S. aureus isolate. A comparison of bacteria type and frequency among gender showed a significant difference with P. vulgaris (P = 0.003) and among profession showed a significant difference with S. aureus (P = 0.004). CONCLUSION: The present study indicates that MPs can serve as a vector for both pathogenic and non-pathogenic organisms. Therefore, full guidelines about restricting the use of MPs in laboratory environments, hand hygiene and frequent decontamination of MPs are recommended to limit the risk of cross-contamination and healthcare-associated infections caused by MPs.

5.
Parasitology ; 146(12): 1602-1614, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31303180

RESUMEN

This cross-sectional study aimed to determine the prevalence and risk factors of S. stercoralis infection among 1142 Orang Asli primary schoolchildren in six different states of Peninsular Malaysia. Fecal samples were examined using direct smear, formalin-ether sedimentation (FES), agar plate culture (APC) and PCR techniques. Overall, 15.8% of the children were found to be infected with S. stercoralis. The prevalence was 0.2, 1.3, 15.2 and 13.7% by direct smear, FES, APC and PCR, respectively. Multivariate analysis showed that an age of >10 years, being male, belonging to a Proto-Malay tribe, belonging to the Senoi tribe, indiscriminate defecation, using an unimproved water source for drinking water and not wearing shoes when outside were the significant risk factors of infection among these children. In conclusion, we provide new evidence on the occurrence of S. stercoralis in Malaysia to show that there is a relatively high prevalence of infection among Orang Asli schoolchildren. Therefore, the use of specific methods for detecting S. stercoralis should be considered when screening these children for intestinal parasites. Moreover, prevention and control measures specific to S. stercoralis should be integrated into the intestinal parasitic infections control programme in Malaysia.


Asunto(s)
Strongyloides stercoralis/aislamiento & purificación , Estrongiloidiasis/epidemiología , Animales , Niño , Estudios Transversales , Femenino , Humanos , Malasia/epidemiología , Masculino , Prevalencia , Factores de Riesgo , Estrongiloidiasis/diagnóstico , Estrongiloidiasis/transmisión
6.
Trop Med Int Health ; 22(4): 493-504, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28151567

RESUMEN

OBJECTIVES: To investigate the molecular epidemiology of Entamoeba histolytica, E. dispar and E. moshkovskii infections among rural communities in Yemen. METHODS: In a community-based study, faecal samples were collected from 605 participants and examined by wet mount, formalin-ether sedimentation, trichrome staining and nested multiplex PCR techniques. Demographic, socio-economic and environmental information was collected using a pre-tested questionnaire. RESULTS: Overall, 324 (53.6%) of the samples were positive for Entamoeba cysts and/or trophozoites by microscopic examination. Molecular analysis revealed that 20.2%, 15.7% and 18.2% of the samples were positive for E. histolytica, E. dispar and E. moshkovskii, respectively. Multivariate analysis showed different sets of species-specific risk factors among these communities. Educational level was identified as the significant risk factor for E. histolytica; age and gender were the significant risk factors for E. moshkovskii; and sources of drinking water and consumption of unwashed vegetables were the significant risk factors for E. dispar. Moreover, living in coastal/foothill areas and presence of other infected family members were risk factors for both E. histolytica and E. moshkovskii infections. CONCLUSION: The study reveals that Entamoeba spp. infection is highly prevalent among rural communities in Yemen, with E. histolytica, E. dispar and E. moshkovskii differentiated for the first time. Identifying and treating infected family members, providing health education pertinent to good personal and food hygiene practices and providing clean drinking water should be considered in developing a strategy to control intestinal parasitic infections in these communities, particularly in the coastal/foothill areas of the country.


Asunto(s)
Entamoeba/crecimiento & desarrollo , Entamebiasis/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , Agua Potable/parasitología , Entamoeba/genética , Entamoeba histolytica/genética , Entamebiasis/epidemiología , Entamebiasis/parasitología , Heces/parasitología , Femenino , Humanos , Higiene , Lactante , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Reacción en Cadena de la Polimerasa/métodos , Factores de Riesgo , Factores Socioeconómicos , Yemen , Adulto Joven
7.
Artículo en Inglés | MEDLINE | ID: mdl-27405127

RESUMEN

The epidemiology and environmental factors affecting transmission of human microsporidiosis are poorly understood. We conducted the present study to determine the prevalence and risk factors associated with asymptomatic intestinal microsporidiosis among aboriginal school children in the Kuala Krau District, Pahang State, Malaysia. We collected stool samples from 255 school children and examined the samples using Gram-chromotrope Kinyoun stain. We also collected demographic, socioeconomic, environmental and personal hygiene information using a pre-tested questionnaire. Sixty-nine of the children was positive for microsporidia: 72.5% and 27.5% were low (1+) and moderate (2+) excretions of microsporidia spores, respectively. Univariate and multivariate analyses showed being aged 10 years (p = 0.026), using an unsafe water supply as a source for drinking water (p = 0.044) and having close contact with domestic animals (p = 0.031) were all significantly associated with microsporidial infection among study subjects. Our findings suggest asymptomatic intestinal microsporidiosis is common in the study population, more than previously reported. In the study population, control measures need to be implemented, such as good personal hygiene, proper sanitation and safe drinking water supply.


Asunto(s)
Infecciones Asintomáticas/epidemiología , Microsporidiosis/epidemiología , Niño , Heces/microbiología , Humanos , Malasia/epidemiología , Nativos de Hawái y Otras Islas del Pacífico , Prevalencia , Factores de Riesgo , Estudiantes
8.
Artículo en Inglés | MEDLINE | ID: mdl-26863854

RESUMEN

Clinical manifestations of giardiasis vary from asymptomatic infection to chronic diarrhea. A total of 611 stool samples from Aboriginal participants residing in Jelebu, Gerik and Temerloh States, Malaysia, ages 2 to 74 years were screened for Giardia intestinalis using microscopic examination and sequence analysis of a fragment of nested-PCR amplified triosephosphate isomerase (tpi) gene. Demographic data was collected through a structured questionnaire. tpi was successfully amplified from 98/110 samples microscopically positive for G. intestinalis, with 62 and 36 belonging to assemblage A and B, respectively. There is a significant correlation between assemblage A and symptomatic infection only in participants of < 15 years of age. In the other age group, host factors may have more effects on the presence of clinical signs and symptoms than G. intestinalis assemblage types.


Asunto(s)
Giardia lamblia/fisiología , Giardiasis/epidemiología , Proteínas Protozoarias/genética , Triosa-Fosfato Isomerasa/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Heces/parasitología , Femenino , Giardia lamblia/genética , Giardiasis/parasitología , Humanos , Malasia/epidemiología , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Adulto Joven
9.
Artículo en Inglés | MEDLINE | ID: mdl-26863855

RESUMEN

Dientamoeba fragilis is a trichomonad parasite that can infect the gastrointestinal tract of humans causing gastrointestinal disease. Little is known about its epidemiology. We evaluated the prevalence of D. fragilis by conducting a cross sectional study of an Orang Asli population in rural Malaysia. We examined stool samples from 150 participants for D. fragilis using Wheatley's trichrome stain and collected demographic data from each participant using a structured questionnaire. Five participants (3.3%) had D. fragilis in their stool; four of these were aged < 15 years; 3 were male and 2 were female. All participants with positive stool sample for D. fragilis were symptomatic; 3 had diarrhea and 2 had other gastrointestinal symptoms. D. fragilis is present in the study population. Further studies are needed to determine the virulence, pathogenicity and mode of transmission of D. fragilis in the study population.


Asunto(s)
Dientamoeba/aislamiento & purificación , Dientamebiasis/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Estudios Transversales , Dientamebiasis/parasitología , Heces/parasitología , Femenino , Humanos , Malasia/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Población Rural , Encuestas y Cuestionarios , Adulto Joven
10.
BMC Infect Dis ; 14: 78, 2014 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-24520940

RESUMEN

BACKGROUND: Giardia duodenalis is a flagellate parasite which has been considered the most common protozoa infecting human worldwide. Molecular characterization of G. duodenalis isolates have revealed the existence of eight groups (Assemblage A to H) which differ in their host distribution. Assemblages A and B are found in humans and in many other mammals. METHODS: This cross-sectional study was conducted to identify assemblage's related risk factors of G. duodenalis among Orang Asli in Malaysia. Stool samples were collected from 611 individuals aged between 2 and 74 years old of whom 266 were males and 345 were females. Socioeconomic data were collected through a pre-tested questionnaire. All stool samples were processed with formalin-ether sedimentation and Wheatley's trichrome staining techniques for the primary identification of G. duodenalis. Molecular identification was carried out by the amplification of a triosephosphate isomerase gene using nested-PCR assay. RESULTS: Sixty-two samples (10.2%) were identified as assemblage A and 36 (5.9%) were assemblage B. Risk analysis based on the detected assemblages using univariate and logistic regression analyses identified subjects who have close contact with household pets i.e. dogs and cats (OR = 2.60; 95% CI = 1.42, 4.78; P = 0.002) was found to be significant predictor for assemblage A. On the other hand, there were three significant risk factors caused by assemblage B: (i) children ≤15 years old (OR = 2.33; 95% CI = 1.11, 4.87; P = 0.025), (ii) consuming raw vegetables (OR = 2.82; 95% CI = 1.27, 6.26; P = 0.011) and (iii) the presence of other family members infected with giardiasis (OR = 6.31; 95% CI = 2.99, 13.31; P < 0.001). CONCLUSIONS: The present study highlighted that G. duodenalis infection among Orang Asli was caused by both assemblages with significant high prevalence of assemblage A. Therefore, taking precaution after having contact with household pets and their stool, screening and treating infected individuals, awareness on the importance of good health practices and washing vegetables are the practical intervention ways in preventing giardiasis in Orang Asli community.


Asunto(s)
Giardia lamblia , Giardiasis/epidemiología , Triosa-Fosfato Isomerasa/genética , Adolescente , Adulto , Anciano , Animales , Gatos , Niño , Preescolar , Estudios Transversales , Perros , Heces/parasitología , Femenino , Humanos , Malasia/epidemiología , Masculino , Persona de Mediana Edad , Epidemiología Molecular , Mascotas , Filogenia , Reacción en Cadena de la Polimerasa , Prevalencia , Factores de Riesgo , Clase Social , Encuestas y Cuestionarios , Adulto Joven
11.
Korean J Parasitol ; 51(2): 231-6, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23710093

RESUMEN

The present study was conducted to investigate the clinical outcomes of Entamoeba histolytica infection in symptomatic and asymptomatic Orang Asli (aborigine) communities in Malaysia. Examination was performed on 500 stool samples obtained from Orang Asli communities in 3 different states using formalin-ether concentration, trichrome staining, and single-round PCR techniques. Out of 500 stool samples, single infection of E. histolytica, Entamoeba dispar, and Entamoeba moshkovskii was identified in 3.2%, 13.4%, and 1%, respectively. In addition, 10 samples had mixed infections with E. histolytica and E. dispar. Six samples containing E. dispar were also positive for E. moshkovskii, and only 2 samples had E. histolytica in association with E. dispar and E. moshkovskii. Seventeen E. histolytica-positive samples were from symptomatic subjects, whereas the remaining 11 samples came from asymptomatic subjects. These findings suggest a predominant distribution of pathogenic potential of E. histolytica strains in this community. Therefore, further studies on genotyping of E. histolytica is required, to find out association between E. histolytica genotype and the outcome of the infection.


Asunto(s)
Entamoeba/clasificación , Entamoeba/patogenicidad , Entamebiasis/patología , Variación Genética , Adolescente , Adulto , Enfermedades Asintomáticas , Niño , Preescolar , Coinfección/parasitología , Coinfección/patología , Entamoeba/aislamiento & purificación , Entamebiasis/parasitología , Heces/parasitología , Femenino , Humanos , Malasia , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
12.
Am J Vet Res ; 84(8)2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37353216

RESUMEN

OBJECTIVE: The objective of this study was to determine bacterial flora throughout the gastrointestinal tract of a saltwater crocodile (Crocodylus porosus) using 16S rRNA gene analysis. ANIMALS: A convention on international trade in endangered species (CITES) of wild fauna and flora registered crocodile farm, provided a healthy male saltwater crocodile, Crocodylus porosus for this study. PROCEDURES: Three samples were taken from the oral cavity, 3 samples from the proximal region of the small intestine (jejunum), and 3 samples from the distal part of the large intestine of the gastrointestinal tract of C. porosus were obtained using sterile cotton swabs. Next, swabs were placed in 15 mL sterile centrifuge tubes, individually, and kept on ice for immediate transportation to the laboratory. This was followed by 16S rRNA gene analysis using specific primers (341F-CCTAYGGGRBGCASCAG, and 806R-GGACTACNNGGGTATCTAAT). Amplicons were sequenced on Illumina paired-end platform, and bacterial gastrointestinal communities, the relative abundance of taxa, and principal component and coordinate analysis were performed. RESULTS: The findings revealed that bacterial community structures from differing regions exhibited several differences. The number of observed bacterial operational taxonomic units (OTUs) was 153 in the oral cavity, 239 in the small intestine, and 119 in the large intestine of C. porosus. The small intestine reflects the highest richness. In contrast, the large intestine exhibited the least richness of microbial communities. Relative abundance of taxa showed that Proteobacteria, Bacteroidetes, and Firmicutes were dominant in all 3 sample sites. Pseudomonas differed in the oral cavity and the large intestine, with the latter exhibiting less distribution of Pseudomonas. Stenotrophomonas and Castellaniella were higher in the oral cavity, while the relative abundance of Comamonas and Salmonella was higher in the small intestine. Conversely, the relative abundance of Salmonella and Pannonibacter was augmented in the large intestine. CLINICAL RELEVANCE: For the first time, this study demonstrates the bacterial diversity along the segments of the gastrointestinal tract of C. porosus. Bacterial flora varies throughout the gastrointestinal tract. Although further studies using large cohorts are warranted; however, our findings suggest that microbiome composition may have the potential as a biomarker in determining the overall health and well-being of C. porosus.


Asunto(s)
Caimanes y Cocodrilos , Masculino , Animales , Caimanes y Cocodrilos/genética , ARN Ribosómico 16S/genética , Comercio , Internacionalidad , Tracto Gastrointestinal , Bacterias/genética
13.
Diseases ; 11(2)2023 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-37092440

RESUMEN

Given the opportunity and access, pathogenic protists (Balamuthia mandrillaris and Naegleria fowleri) can produce fatal infections involving the central nervous system. In the absence of effective treatments, there is a need to either develop new antimicrobials or enhance the efficacy of existing compounds. Nanocarriers as drug delivery systems are gaining increasing attention in the treatment of parasitic infections. In this study, novel nanocarriers conjugated with amphotericin B and curcumin were evaluated for anti-amoebic efficacy against B. mandrillaris and N. fowleri. The results showed that nanocarrier conjugated amphotericin B exhibited enhanced cidal properties against both amoebae tested compared with the drug alone. Similarly, nanocarrier conjugated curcumin exhibited up to 75% cidal effects versus approx. 50% cidal effects for curcumin alone. Cytopathogenicity assays revealed that the pre-treatment of both parasites with nanoformulated-drugs reduced parasite-mediated host cellular death compared with the drugs alone. Importantly, the cytotoxic effects of amphotericin B on human cells alone were reduced when conjugated with nanocarriers. These are promising findings and further suggest the need to explore nanocarriers as a means to deliver medicine against parasitic infections.

14.
Parasitology ; 139(12): 1521-5, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22939193

RESUMEN

Entamoeba moshkovskii and Entamoeba dispar are microscopically indistinguishable from the pathogenic species Entamoeba histolytica. Although sporadic cases of human infection with E. moshkovskii have been reported, the amoeba is still considered primarily as a free-living amoeba. A cross-sectional study was carried out among Orang Asli communities in 3 different states of Peninsular Malaysia. Fecal samples were examined by formalin-ether sedimentation and trichrome staining techniques and then single-round PCR assay was used to detect E. moshkovskii. Out of 500 fecal samples examined microscopically, 93 (18·6%) samples were positive for E. histolytica/E. dispar/E. moshkovskii complex cysts and/or trophozoites. PCR products were detected in 106 fecal samples. E. moshkovskii isolates were detected in 13 (12·3%) fecal samples. Of the 13 E. moshkovskii-positive samples, 5 were of single isolation of E. moshkovskii, 6 were also positive for E. dispar, and only 2 samples were positive for E. dispar and E. histolytica. Moreover, 3 E. moshkovskii-positive samples were collected from symptomatic individuals while the remaining 10 samples were from asymptomatic subjects. This is the first report on the identification of E. moshkovskii in Malaysia. Further studies are needed to confirm the pathogenicity of E. moshkovskii infection and determine the epidemiology among Orang Asli communities in Malaysia.


Asunto(s)
Entamoeba/genética , Entamebiasis/parasitología , ADN Protozoario/genética , Entamoeba/clasificación , Entamoeba/aislamiento & purificación , Entamebiasis/epidemiología , Heces/parasitología , Humanos , Malasia/epidemiología , Reacción en Cadena de la Polimerasa , Prevalencia
15.
Antibiotics (Basel) ; 11(6)2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35740156

RESUMEN

Naegleria fowleri and Balamuthia mandrillaris are pathogenic free-living amoebae that infect the central nervous system with over 95% mortality rates. Although several compounds have shown promise in vitro but associated side effects and/or prolonged approval processes for clinical applications have led to limited success. To overcome this, drug repurposing of marketed compounds with known mechanism of action is considered a viable approach that has potential to expedite discovery and application of anti-amoebic compounds. In fact, many of the drugs currently employed in the treatment of N. fowleri and B. mandrillaris, such as amphotericin B, fluconazole, rifampin and miltefosine, are repurposed drugs. Here, we evaluated a range of clinical and laboratory compounds including metformin, quinclorac, indaziflam, inositol, nateglinide, 2,6-DNBT, trans-cinnamic acid, terbuthylazine, acarbose, glimepiride, vildagliptin, cellulase, thaxtomin A, repaglinide and dimethyl peptidase (IV) inhibitor against N. fowleri and B. mandrillaris. Anti-amoebic assays revealed that indaziflam, nateglinide, 2,6-DNBT, terbuthylazine, acarbose and glimepiride exhibited potent amoebicidal properties against both N. fowleri and B. mandrillaris. Notably, all compounds tested showed minimal human (HaCaT) cell cytotoxicity as determined by lactate dehydrogenase release. Prospective research using animal models is warranted to determine the potential of these repurposed compounds, as well as the need for investigating the intranasal route of delivery to treat these devastating infections.

16.
Pathogens ; 11(12)2022 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-36558808

RESUMEN

Amoebic keratitis and encephalitis are mainly caused by free-living amoebae of the genus Acanthamoeba, which consists of both pathogenic and nonpathogenic species. The global distribution, amphizoic properties and the severity of the disease caused by Acanthamoeba species have inspired the scientific community to put more effort into the isolation of Acanthamoeba, besides exploring the direct and indirect parameters that could signify a pathogenic potential. Therefore, this study was performed to characterize the pathogenic potential of Acanthamoeba isolated from contact lens paraphernalia and water sources in Malaysia. Various methodologies were utilized to analyze the thermotolerance and osmotolerance, the secretion level of proteases and the cytopathic effect of trophozoites on the cell monolayer. In addition, the in vitro cytopathogenicity of these isolates was assessed using the LDH-release assay. A total of 14 Acanthamoeba isolates were classified as thermo- and osmotolerant and had presence of serine proteases with a molecular weight of 45-230 kDa. Four T4 genotypes isolated from contact lens paraphernalia recorded the presence of serine-type proteases of 107 kDa and 133 kDa. In contrast, all T3 genotypes isolated from environmental samples showed the presence of a 56 kDa proteolytic enzyme. Remarkably, eight T4 and a single T3 genotype isolates demonstrated a high adhesion percentage of greater than 90%. Moreover, the use of the HeLa cell monolayer showed that four T4 isolates and one T3 isolate achieved a cytopathic effect in the range of 44.9-59.4%, indicating an intermediate-to-high cytotoxicity level. Apart from that, the LDH-release assay revealed that three T4 isolates (CL5, CL54 and CL149) and one T3 isolate (SKA5-SK35) measured an exceptional toxicity level of higher than 40% compared to other isolates. In short, the presence of Acanthamoeba T3 and T4 genotypes with significant pathogenic potential in this study reiterates the essential need to reassess the functionality of other genotypes that were previously classified as nonpathogenic isolates in past research.

17.
Saudi J Biol Sci ; 28(4): 2352-2359, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33911949

RESUMEN

The incidence of Acanthamoeba keratitis has been increasing since the previous decades, especially among contact lens users. This infection is majorly caused by the use of ineffective contact lens disinfecting solution. Thus, this study was conducted to evaluate the in vitro effects of multi-purpose disinfecting solutions (MPDS) against Acanthamoeba trophozoites and cysts. Acanthamoeba genotype T4 isolated from contact lens paraphernalia and an environmental strains were propagated for trophozoite or cyst-containing culture and adjusted in final concentration of 1 × 105 cells/ml. Amoebicidal and cysticidal assays were conducted by incubating trophozoites and cysts with OPTI-FREE® Express®, ReNu® Fresh™, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive according to the manufacturer's minimum recommended disinfectant time (MMRDT) for up to 12 h at 30 °C. Trypan blue hemocytometer-based microscopic counts determined amoebicidal and cysticidal effects. The viability of Acanthamoeba trophozoites and cysts was confirmed by re-inoculated them in the 1.5% non-nutrient agar plates. It was found that none of the MPDS showed amoebicidal and cysticidal effects during the MMRDT. However, OPTI-FREE® Express® demonstrated a significant differences in average cell reduction for both stages within MMRDT. When subjected to 12 h exposure, both OPTI-FREE® Express® and ReNu® Fresh™ led to significant reduction in the number of trophozoite and cyst cells. Notably, Complete® Multi-Purpose Solution and AVIZOR Unica® Sensitive did appreciably improve the solution effectiveness towards trophozoite cells when incubated for 12 h. All MPDS were largely ineffective, with 100% survival of all isolates at MMRDT, while OPTI-FREE® Express® showed limited amoebicidal activity against the contact lens paraphernalia isolate, however, it was more against the environmental strains after 12 h incubation time. The commercially available MPDS employed in this research offered minimal effectiveness against the protozoa despite the contact time. Improvement or development of new solution should consider the adjustment of the appropriate disinfectant concentration, adequate exposure time or the incorporation of novel chemical elements, which are effective against Acanthamoeba for accelerated disinfecting and more reduction of potential exposure of contact lens users to Acanthamoeba keratitis.

18.
Artículo en Inglés | MEDLINE | ID: mdl-33809939

RESUMEN

Stress, anxiety, and depression (SAD) have a negative impact on the learning and academic performance of university students. Hence, this study aimed to determine the prevalence, as well as the risk factors associated with SAD among a cohort of students pursuing undergraduate degree courses in health sciences. This is part of the strategy in building a healthy nation. A questionnaire containing socio-demographic factors and the short version of Depression, Anxiety, and Stress Scale-21 (DASS-21) was used to assess the likelihood of psychological distress. Logistic regression analysis was conducted to determine the risk factors of SAD. In total, 449 students completed the questionnaire (93.9% response rate). Of these, 65% had stress, 85.1% had anxiety and 51.4% had depression. Most cases of stress (74.6%) and depression (66.2%) were of normal-to-mild level, while 74.6% of them showed moderate-to-extremely severe anxiety. There was a statistically significant association between stress score and the year of study. In the regression analysis, poor sleep quality and fatigue were risk factors of anxiety and depression, whereas low-grade fever and frequent headaches were risk factors for stress and anxiety. Stress, anxiety, and depression scores were significantly higher among students studying medical imaging. A substantial proportion of health science students are suffering from SAD. This study recommends screening and close monitoring of the above-mentioned predictors and the formulation of comprehensive intervention strategies for students with SAD.


Asunto(s)
Depresión , Estudiantes de Medicina , Ansiedad/epidemiología , Estudios Transversales , Depresión/epidemiología , Humanos , Prevalencia , Factores de Riesgo , Estrés Psicológico/epidemiología , Estudiantes
19.
Pathog Glob Health ; 114(3): 145-159, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32249689

RESUMEN

A cross-sectional survey was conducted among 1,142 Orang Ali schoolchildren in six states of Peninsular Malaysia to investigate the current prevalence and risk factors of STH infections. Faecal samples were examined using direct smear, formalin-ether sedimentation, Kato-Katz, and Harada-Mori methods. A pre-tested questionnaire was used to collect information on the demographic, socioeconomic, personal hygiene, and health status of the participants. Overall, 70.1% (95% CI = 67.4, 72.7) of the participants were infected with at least one of the STH species. The prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworm infections was 63.1%, 61.8% and 11.5%, respectively. Moderate-to-heavy STH infections accounted for 61.3% of the total infections. Univariate and logistic regression analyses revealed different sets of risk factors, with age (> 10 years) being the significant risk factor of all three STH species. Moreover, other species-specific risk factors were identified including being a member of the Senoi tribe, family size (≥ 7 members), school size (150-250 pupils), maternal unemployment, unimproved source of drinking water, lacking improved toilet in the house, inadequate WASH facilities at school, not washing hands before eating, and not washing fruits before eating; presence of domestic animals, and not wearing shoes when outside. The high prevalence of STH infections found in the study population exceeds the WHO policy intervention threshold (20% prevalence). Thus, an innovative holistic approach should be adopted to control STH infections among these children as part of the efforts to improve the quality of life of the entire Orang Asli population. .


Asunto(s)
Helmintiasis , Suelo , Ancylostomatoidea , Animales , Ascaris lumbricoides , Niño , Estudios Transversales , Heces , Femenino , Helmintiasis/epidemiología , Helmintiasis/prevención & control , Humanos , Malasia/epidemiología , Masculino , Prevalencia , Calidad de Vida , Suelo/parasitología , Trichuris
20.
Iran J Parasitol ; 13(1): 127-136, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29963095

RESUMEN

BACKGROUND: This study evaluated the performance of routine permanent stain and cultivation method in comparison with polymerase chain reaction assay as the reference technique to detect Blastocystis sp. METHODS: A cross-sectional study was conducted among aboriginal populations that reside in Pahang, Peninsular Malaysia in Feb to Mar 2015. A total of 359 stool samples were examined using Wheatley's trichrome stain, in-vitro cultivation in Jones' medium and PCR assay. Positive amplicons were subjected to sequencing and phylogenetic analysis. RESULTS: Fifty-six (15.6%) samples were detected positive with Blastocystis sp. by Wheatley's trichrome stain and 73 (20.3%) by in-vitro culture, while PCR assay detected 71 (19.8%) positive samples. Detection rate of Blastocystis sp. was highest in combination of microscopic techniques (27.9%). The sensitivity and specificity of Wheatley's trichrome staining and in-vitro culture techniques compared to PCR assay were 49.3% (95% CI: 37.2-61.4) and 92.7% (95% CI: 89.1-95.4) and 39.4% (95% CI: 28.0-51.8) and 84.4% (95% CI: 79.7-88.4), respectively. However, the sensitivity [60.6% (95% CI: 48.3-71.9)] of the method increased when both microscopic techniques were performed together. False negative results produced by microscopic techniques were associated with subtype 3. The agreement between Wheatley's trichrome stain, in-vitro culture and combination of microscopic techniques with PCR assay were statistically significant by Kappa statistics (Wheatley's trichrome stain: K = 0.456, P<0.001; in-vitro culture: K = 0.236, P<0.001 and combination techniques: K = 0.353, P<0.001). CONCLUSION: The combination of microscopic technique is highly recommended to be used as a screening method for the diagnosis of Blastocystis infection either for clinical or epidemiological study to ensure better and accurate diagnosis.

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