Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and hap...Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and haplotype.Methods:Thirty-nine blood samples infected with P.knowlesi were collected in Sabah,Malaysian Borneo and Peninsular Malaysia.The S-type SSU rRNA gene was amplified using polymerase chain reaction,cloned into a vector,and sequenced.The natural selection and haplotype of the S-type SSU rRNA gene sequences were determined using DnaSP v6 and illustrated using NETWORK v10.This study's 39 S-type SSU rRNA sequences and eight sequences from the Genbank database were subjected to phylogenetic analysis using MEGA 11.Results:Overall,the phylogenetic analysis showed no evidence of a geographical cluster of P.knowlesi isolates from different areas in Malaysia based on the S-type SSU rRNA gene sequences.The S-type SSU rRNA gene sequences were relatively conserved and with a purifying effect.Haplotype sharing of the S-type SSU rRNA gene was observed between the P.knowlesi isolates in Sabah,Malaysian Borneo,but not between Sabah,Malaysian Borneo and Peninsular Malaysia.Conclusions:This study suggests that the S-type SSU rRNA gene of P.knowlesi isolates in Sabah,Malaysian Borneo,and Peninsular Malaysia has fewer polymorphic sites,representing the conservation of the gene.These features make the S-type SSU rRNA gene suitable for comparative studies,such as determining the evolutionary relationships and common ancestry among P.knowlesi species.展开更多
Background:Intestinal parasitic infections(IPIs)among indigenous people have been widely documented in Malaysia,however,the prevalence of these infections remains high.In the past,most studies have focused on specific...Background:Intestinal parasitic infections(IPIs)among indigenous people have been widely documented in Malaysia,however,the prevalence of these infections remains high.In the past,most studies have focused on specific species of parasites but polyparasitism has received limited attention.In addition,epidemiology studies on indigenous people tend to consider them as a homogenous group,whereas in reality different sub-ethnic groups have different cultural and living practices.Variations in living habits such as personal hygiene practices may predispose different groups to different parasitic infections.To better understand prevalence and risk factors of intestinal parasitism among different sub-ethnic groups,the present study was conducted among two sub-ethnic groups of indigenous people(Temuan and Mah Meri)residing in Selangor state,Malaysia.Methods:A cross-sectional study that focused on two distinct sub-ethnic groups was carried out from February to September 2014.Faecal samples were collected from 186 participants and examined using the formalin-ether sedimentation technique.A molecular approach was adopted to conduct a genetic characterisation of the parasites.Additionally,questionnaires were administered to obtain information on the demographics,socioeconomic backgrounds and behavioural risks relating to the participants,as well as information about their environments.Statistical analyses(i.e.binary and multivariate logistic regression analyses)were performed to measure risk factors.Results:For Temuan communities,trichuriasis(64.2%)was the most common infection found,preceding hookworm infection(34%),ascariasis(7.5%),giardiasis(14.2%)and amoebiasis(7.5%).As for the Mah Meri communities,trichuriasis(77.5%)prevailed over ascariasis(21.3%),hookworm(15%),giardiasis(7.5%)and amoebiasis(3.8%).Significant differences in proportions of trichuriasis,ascariasis and hookworm infections were observed between the Temuan and Mah Meri sub-ethnic groups.Polyparasitism was more common among the Temuan sub-ethnic group(41.5%)compared to the Mah Meri sub-ethnic group(32.5%),with the majority of participants harbouring two parasites concurrently(Temuan:33%,Mah Meri:20%).Trichuris trichiura and Ascaris lumbricoides co-infections were most prevalent(10%)among the Mah Meri communities,while a co-infection of T.trichiura with hookworm(19.8%)was most common among the Temuan communities.Multivariate analyses showed that being unemployed,having a large family and drinking unboiled water were found to be significantly associated with intestinal parasitism.Conclusion:The present study highlights substantial polyparasitism and risk factors for infections in the Temuan and Mah Meri sub-ethnic groups.The high prevalence of IPIs among these two sub-ethnic groups indicates that parasitic infections are important health issues in these communities.Hence,it is imperative to implement sound intervention strategies such as periodic preventive chemotherapy coupled with health education in order to reduce and eradicate these infections.展开更多
基金This study was supported by the Ministry of Higher Education,Malaysia(FRGS0322-SG-1/2013)Universiti Malaysia Sabah(GUG0521-2/2020).
文摘Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and haplotype.Methods:Thirty-nine blood samples infected with P.knowlesi were collected in Sabah,Malaysian Borneo and Peninsular Malaysia.The S-type SSU rRNA gene was amplified using polymerase chain reaction,cloned into a vector,and sequenced.The natural selection and haplotype of the S-type SSU rRNA gene sequences were determined using DnaSP v6 and illustrated using NETWORK v10.This study's 39 S-type SSU rRNA sequences and eight sequences from the Genbank database were subjected to phylogenetic analysis using MEGA 11.Results:Overall,the phylogenetic analysis showed no evidence of a geographical cluster of P.knowlesi isolates from different areas in Malaysia based on the S-type SSU rRNA gene sequences.The S-type SSU rRNA gene sequences were relatively conserved and with a purifying effect.Haplotype sharing of the S-type SSU rRNA gene was observed between the P.knowlesi isolates in Sabah,Malaysian Borneo,but not between Sabah,Malaysian Borneo and Peninsular Malaysia.Conclusions:This study suggests that the S-type SSU rRNA gene of P.knowlesi isolates in Sabah,Malaysian Borneo,and Peninsular Malaysia has fewer polymorphic sites,representing the conservation of the gene.These features make the S-type SSU rRNA gene suitable for comparative studies,such as determining the evolutionary relationships and common ancestry among P.knowlesi species.
基金supported by the University of Malaya Research Grant(RG494-13HTM)the University of Malaya Postgraduate Research Grant(PG032-2014B).
文摘Background:Intestinal parasitic infections(IPIs)among indigenous people have been widely documented in Malaysia,however,the prevalence of these infections remains high.In the past,most studies have focused on specific species of parasites but polyparasitism has received limited attention.In addition,epidemiology studies on indigenous people tend to consider them as a homogenous group,whereas in reality different sub-ethnic groups have different cultural and living practices.Variations in living habits such as personal hygiene practices may predispose different groups to different parasitic infections.To better understand prevalence and risk factors of intestinal parasitism among different sub-ethnic groups,the present study was conducted among two sub-ethnic groups of indigenous people(Temuan and Mah Meri)residing in Selangor state,Malaysia.Methods:A cross-sectional study that focused on two distinct sub-ethnic groups was carried out from February to September 2014.Faecal samples were collected from 186 participants and examined using the formalin-ether sedimentation technique.A molecular approach was adopted to conduct a genetic characterisation of the parasites.Additionally,questionnaires were administered to obtain information on the demographics,socioeconomic backgrounds and behavioural risks relating to the participants,as well as information about their environments.Statistical analyses(i.e.binary and multivariate logistic regression analyses)were performed to measure risk factors.Results:For Temuan communities,trichuriasis(64.2%)was the most common infection found,preceding hookworm infection(34%),ascariasis(7.5%),giardiasis(14.2%)and amoebiasis(7.5%).As for the Mah Meri communities,trichuriasis(77.5%)prevailed over ascariasis(21.3%),hookworm(15%),giardiasis(7.5%)and amoebiasis(3.8%).Significant differences in proportions of trichuriasis,ascariasis and hookworm infections were observed between the Temuan and Mah Meri sub-ethnic groups.Polyparasitism was more common among the Temuan sub-ethnic group(41.5%)compared to the Mah Meri sub-ethnic group(32.5%),with the majority of participants harbouring two parasites concurrently(Temuan:33%,Mah Meri:20%).Trichuris trichiura and Ascaris lumbricoides co-infections were most prevalent(10%)among the Mah Meri communities,while a co-infection of T.trichiura with hookworm(19.8%)was most common among the Temuan communities.Multivariate analyses showed that being unemployed,having a large family and drinking unboiled water were found to be significantly associated with intestinal parasitism.Conclusion:The present study highlights substantial polyparasitism and risk factors for infections in the Temuan and Mah Meri sub-ethnic groups.The high prevalence of IPIs among these two sub-ethnic groups indicates that parasitic infections are important health issues in these communities.Hence,it is imperative to implement sound intervention strategies such as periodic preventive chemotherapy coupled with health education in order to reduce and eradicate these infections.
