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1.
Trop Biomed ; 41(1): 78-83, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38852137

RESUMO

The present study aimed at exploring whether sunlight exposure might account for the relative difference in COVID-19-related morbidity and mortality between tropical and non-tropical countries. A retrospective observational study was designed and data from the World Health Organization weekly COVID-19 epidemiological update was compiled. We examined the total number of confirmed COVID-19 cases per 100 000 population, as well as the total number of COVID-19-related mortalities per 100 000 population. Solar variables data were obtained from the Global Solar Atlas website (https://globalsolaratlas.info/). These data were analyzed to determine the association of sunlight exposure to COVID-19-related morbidity and mortality in tropical and non-tropical countries. Results revealed a statistically significant decrease in the number of confirmed COVID-19 cases per 100 000 population (P<0.001), as well as the number of COVID-19-related mortalities per 100 000 population (P<0.001) between tropical and non-tropical countries. Analyses of sunlight exposure data found that specific photovoltaic power output, global horizontal irradiation, diffuse horizontal irradiation and global tilted irradiation at optimum angle were significantly inversely correlated to COVID-19-related morbidity and mortality. This suggests that stronger sunlight exposure potentially leads to lower COVID-19-related morbidity and mortality. Findings from this study suggest that the relatively low COVID-19-related morbidity and mortality in tropical countries were possibly due to better sunlight exposure that translates into adequate vitamin D status.


Assuntos
COVID-19 , SARS-CoV-2 , Luz Solar , Clima Tropical , COVID-19/mortalidade , COVID-19/epidemiologia , Humanos , Estudos Retrospectivos , Morbidade
2.
Trop Biomed ; 39(3): 444-450, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36214442

RESUMO

Data on the prevalence and associated risk factors of naturally occurring haemoplasmosis in owned cats in Malaysia is limited. Being the most pathogenic of the three known feline haemoplasma species, Mycoplasma haemofelis (Mhf) infection was analysed from 2016 to 2019 to determine the periodical prevalence and associated risk factors in Northeastern Malaysia - Kelantan. Archived patient data of 77 clinically ill cats suspected of having M. haemofelis infection were reviewed in this study. Out of the 77 suspected cases, 53 (68.8%) were clinically diagnosed with haemoplasmosis amongst which 46 (59.7%) of the subpopulation were further confirmed with polymerase chain reaction (PCR). Risk factors for M. haemofelis infection (age, breed, ectoparasitism, household condition, roaming status, and sex) were analysed. There was no significant association of breed, ectoparasitism, household condition (number of cats) and occurrence of clinical signs with feline mycoplasmosis. Young, male and roamer cats were more likely to be diagnosed of mycoplasmosis than other categories of cats in this study. There was also a significant association between cats infected with 'Candidatus Mycoplasma haemominutum' with M. haemofelis. Thus, the coinfection of these two haemoplasma species is not uncommon. This study indicates that infection by M. haemofelis in anaemic cats is a common find in client-owned cats from Northeastern Malaysia. As the natural mode of transmission of haemoplasma infection remain unestablished, information in this study may highlight the importance of this disease and contribute to effective prevention and control strategies to minimize feline infectious anaemia (FIA) caused by M. haemofelis.


Assuntos
Anemia , Doenças do Gato , Infecções por Mycoplasma , Mycoplasma , Animais , Doenças do Gato/epidemiologia , Gatos , Masculino , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/veterinária , Prevalência , Estudos Retrospectivos , Fatores de Risco
3.
Trop Biomed ; 39(4): 518-523, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36602210

RESUMO

Zika virus (ZIKV) infection has emerged as a global health concern following epidemic outbreaks of severe neurological disorders reported in Pacific and Americas since 2016. Therefore, a rapid, sensitive and specific diagnostic test for ZIKV infection is critical for the appropriate patient management and the control of disease spread. A TaqMan minor groove binding (MGB) probe-based quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed based on the conserved sequence regions of 463 ZIKV NS2B genes. The designed ZIKV qRT-PCR assay was evaluated for its detection limit, strain coverage and cross-reactivity. We further assessed the clinical applicability of qRT-PCR assay for ZIKV RNA detection using a total 18 simulated clinical specimens. The detection limit of the qRT-PCR assay was 11.276 ZIKV RNA copies at the 95% probability level (probit analysis, p<= 0.05). Both Asian and African ZIKV strains were detected by the qRT-PCR assay without cross-reacting with DENV-1, DENV-2, DENV-3, DENV-4, CHIKV, JEV, LGTV, GETV and SINV. The qRT-PCR assay demonstrated a perfect agreement (k = 1.000, P < 0.001) with the reference assay; the sensitivity and specificity of the qRT-PCR assay were 100% (95% CI= 79.6-100) and 100% (95% CI= 43.9-100) respectively. The qRT-PCR assay developed in this study is a useful diagnostic tool for the broad coverage detection and quantification of both the Asian and African ZIKV strains.


Assuntos
Dengue , Infecção por Zika virus , Zika virus , Humanos , Zika virus/genética , Infecção por Zika virus/diagnóstico , Transcrição Reversa , Sensibilidade e Especificidade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Reação em Cadeia da Polimerase em Tempo Real , RNA , RNA Viral/genética , RNA Viral/análise
6.
Trop Biomed ; 37(4): 884-895, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33612742

RESUMO

This study was carried out to determine from bacterial profiling to the bacterial profiles of head lice among the Orang Asli communities. The head lice were collected from Orang Asli community volunteers. The surface sterilized head lice pools were subjected to genomic DNA extraction while next generation sequencing of the 16S rRNA gene was performed using the Illumina MiSeq platform. Six female and three male head lice identified as Pediculus humanus capitis were collected. A total of 111 368 number of NGS sequencing reads were recorded while another 223 bacterial taxa sequences were obtained. Symbiotic bacteria showed the highest number of reads, with Arsenophonus and Rhodococcus sequences being the most abundant genera in the female and male samples, respectively. The female head lice contained a more distinct microbial diversity. Amongst the pathogenic bacterial species sequences noted were the methicillin-resistant Staphylococcus aureus, Streptobacillus moniliformis, Haemophilus influenzae, Bordetella pertussis and Acinetobacter baumannii. The 16S rRNA genome sequencing revealed a number of rare and pathogenic bacterial species within the head lice of the Orang Asli. The socio-economic practices of the community which involved forest foraging and hunting, and their poor living conditions potentially facilitated the transmission of zoonotic bacterial pathogens, including those found within the head lice. Hence, there is the possibility that the head lice could serve as vectors for the transmission of pathogenic bacteria. This study highlighted the diverse microbial community found within the head lice's gut of the Orang Asli, with the detection of multiple rare and pathogenic bacteria capable of causing severe infections.


Assuntos
Bactérias/classificação , Pediculus/microbiologia , Animais , Bactérias/isolamento & purificação , Criança , DNA Bacteriano/genética , Etnicidade , Feminino , Humanos , Infestações por Piolhos , Malásia , Masculino , Microbiota , Filogenia , RNA Ribossômico 16S/genética
7.
Trop Biomed ; 37(3): 803-811, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33612793

RESUMO

Ticks are vectors of bacteria, protozoa and viruses capable of causing serious and life threatening diseases in humans and animals. Disease transmission occurs through the transfer of pathogen from tick bites to susceptible humans or animals. Most commonly known tick-borne pathogens are obligate intracellular microorganisms but little is known on the prevalence of culturable pathogenic bacteria from ticks capable of growth on artificial nutrient media. One hundred and forty seven ticks originating from dairy cattle, goats and rodents were collected from nine selected sites in Peninsular Malaysia. The culture of surfacesterilized tick homogenates revealed the isolation of various pathogenic bacteria including, Staphylococcus sp., Corynebacterium sp., Rothia sp., Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli and Bacillus sp. and its derived genera. These pathogens are among those that affect humans and animals. Findings from this study suggest that in addition to the regular intracellular pathogens, ticks could also harbor extracellular pathogenic bacteria. Further studies, hence, would be needed to determine if these extracellular pathogens could contribute to human or animal infection.


Assuntos
Animais Domésticos/parasitologia , Bactérias/classificação , Roedores/parasitologia , Carrapatos/microbiologia , Animais , Bactérias/isolamento & purificação , Bovinos/parasitologia , Feminino , Cabras/parasitologia , Malásia , Masculino
8.
Tropical Biomedicine ; : 884-895, 2020.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-862401

RESUMO

@#This study was carried out to determine from bacterial profiling to the bacterial profiles of head lice among the Orang Asli communities. The head lice were collected from Orang Asli community volunteers. The surface sterilized head lice pools were subjected to genomic DNA extraction while next generation sequencing of the 16S rRNA gene was performed using the Illumina MiSeq platform. Six female and three male head lice identified as Pediculus humanus capitis were collected. A total of 111 368 number of NGS sequencing reads were recorded while another 223 bacterial taxa sequences were obtained. Symbiotic bacteria showed the highest number of reads, with Arsenophonus and Rhodococcus sequences being the most abundant genera in the female and male samples, respectively. The female head lice contained a more distinct microbial diversity. Amongst the pathogenic bacterial species sequences noted were the methicillin-resistant Staphylococcus aureus, Streptobacillus moniliformis, Haemophilus influenzae, Bordetella pertussis and Acinetobacter baumannii. The 16S rRNA genome sequencing revealed a number of rare and pathogenic bacterial species within the head lice of the Orang Asli. The socio-economic practices of the community which involved forest foraging and hunting, and their poor living conditions potentially facilitated the transmission of zoonotic bacterial pathogens, including those found within the head lice. Hence, there is the possibility that the head lice could serve as vectors for the transmission of pathogenic bacteria. This study highlighted the diverse microbial community found within the head lice’s gut of the Orang Asli, with the detection of multiple rare and pathogenic bacteria capable of causing severe infections.

9.
Tropical Biomedicine ; : 803-811, 2020.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-825635

RESUMO

@#Ticks are vectors of bacteria, protozoa and viruses capable of causing serious and life threatening diseases in humans and animals. Disease transmission occurs through the transfer of pathogen from tick bites to susceptible humans or animals. Most commonly known tick-borne pathogens are obligate intracellular microorganisms but little is known on the prevalence of culturable pathogenic bacteria from ticks capable of growth on artificial nutrient media. One hundred and forty seven ticks originating from dairy cattle, goats and rodents were collected from nine selected sites in Peninsular Malaysia. The culture of surfacesterilized tick homogenates revealed the isolation of various pathogenic bacteria including, Staphylococcus sp., Corynebacterium sp., Rothia sp., Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli and Bacillus sp. and its derived genera. These pathogens are among those that affect humans and animals. Findings from this study suggest that in addition to the regular intracellular pathogens, ticks could also harbor extracellular pathogenic bacteria. Further studies, hence, would be needed to determine if these extracellular pathogens could contribute to human or animal infection.

10.
Trop Biomed ; 35(1): 1-9, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33601771

RESUMO

The lifestyles of the indigenous people (Orang Asli) of Peninsular Malaysia who traditionally live close to the forest, put them at higher risk of exposure to zoonotic diseases. Leptospirosis has recently emerged as one of the most important diseases of public health concern. Here, we aimed to obtain a baseline data on the level of Leptospira exposure among the 107 Orang Asli volunteers using a recombinant antigen-based ELISA, previously shown to have sensitivity of ~90.0% in comparison to the microscopic agglutination test (MAT). Among the Orang Asli volunteers in this study, 60.7% had IgM against Leptospira and 57.9% were antiLeptospira IgG positive. Of these seropositive individuals, 29.9% had both anti-Leptospira IgM and IgG antibodies. Age was found to be a significant predictor for exposure to Leptospira (P < 0.05) with the younger Orang Asli population more likely to be tested positive for antiLeptospira IgM. The finding of high Leptospira exposure among the Orang Asli volunteers could be due to their socio-economic practices and dependency on the forest for their livelihood. The rapid and sensitive recombinant antigen-based ELISA used in the study, could possibly complement MAT for the epidemiological surveillance of leptospirosis, especially among the underserved populations.

11.
Trop Biomed ; 33(4): 837-841, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33579083

RESUMO

Motile enterococci such as Enterococcus gallinarum has the ability to acquire and transfer antibiotic resistance genes to other enterococci. Even though infections caused by E. gallinarum are rare, the discovery of this bacteria in food sources and in clinical environments is disturbing. Here, we report the isolation and identification of E. gallinarum from the wound of a hospital in-patient. The isolate was identified using 16S rDNA sequencing. Isolate 146 harboured the vanA and vanC1 gene clusters, was vancomycin-susceptible, and displayed resistance to ampicillin, penicillin, erythromycin and teicoplanin. This isolate also showed intermediate resistance to linezolid and sequencing of the 23S rRNA peptidyl transferase region did not unveil any known mutations associated to the conferment of linezolid resistance. The presence of vanA did not confer resistance to vancomycin. Structural analyses into the Tn1546 transposon carrying the vanA gene revealed distinct genetic variations in the vanS, vanY and vanS-vanH intergenic region that could be associated to the atypical antibiotic resistance phenotypes of isolate 146. Finding from this study are suggestive of the occurrence of interspecies horizontal gene transfer and that similarities in genotypic characteristic may not necessarily correlate with actual antibiotic resistance pattern of E. gallinarum.

12.
Trop Biomed ; 33(3): 577-582, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33579131

RESUMO

The ability to acquire antibiotic resistance and virulence has propelled Enterococcus faecalis to become a major nosocomial pathogen. In Malaysia, data on the antibiotic resistance determinants and virulence of Enterococcus circulating strains are still scarce. This study aimed to assess the genotype of an E. faecalis isolate initially identified as Streptococcus uberis, examine the antibiotic resistance genotypes, analyze the genetic variations within Tn1546 and investigate the presence of virulence genes. The E. faecalis isolate was genetically characterized using multilocus sequence typing (MLST). Minimum inhibitory concentrations to vancomycin and teicoplanin were determined. Antibiotic resistance and other virulence genes were amplified using nucleic acid polymerase chain reaction. Mapping of the Tn1546 transposon was performed and compared to the prototype sequences. The E. faecalis isolate was found to have a MLST profile corresponding to sequence type 6. The isolate was resistant to teicoplanin but susceptible to vancomycin. Its genome consisted the vanA and vanC1 genes. Novel genetic variations in the vanS, vanS-vanH intergenic region and vanY genes were present and six virulence genes were detected. The detection of the vanC1 gene, thought to be non-transferable, suggests the potential emergence of inter-species enterococcal vanC1 gene transfer. The peculiar antibiotics resistance phenotype of this E. faecalis isolate could be associated to the novel genetic variations found. This study highlights the presence of E. faecalis belonging to the high-risk clonal complex with multiple virulence factors in Malaysia.

13.
Trop Biomed ; 33(3): 589-593, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33579133

RESUMO

Members of the genus Kocuria are commonly found in the environment and they are also commensals of the mammalian skin and oropharynx mucosa. Human infections, although rare, are increasingly being reported recently suggesting that this genus has mostly been overlooked or misidentified. Its transmission route however, is still not known. We report here the isolation and identification of a Kocuria marina isolate from the lung of a wild urban rat (Rattus rattus diardii) caught at a wet market. The isolate was susceptible to most of the commonly used antibiotics. The finding suggests a possibility that rats could be a vector for K. marina.

14.
Tropical Biomedicine ; : 837-841, 2016.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-630859

RESUMO

Motile enterococci such as Enterococcus gallinarum has the ability to acquire and transfer antibiotic resistance genes to other enterococci. Even though infections caused by E. gallinarum are rare, the discovery of this bacteria in food sources and in clinical environments is disturbing. Here, we report the isolation and identification of E. gallinarum from the wound of a hospital in-patient. The isolate was identified using 16S rDNA sequencing. Isolate 146 harboured the vanA and vanC1 gene clusters, was vancomycin-susceptible, and displayed resistance to ampicillin, penicillin, erythromycin and teicoplanin. This isolate also showed intermediate resistance to linezolid and sequencing of the 23S rRNA peptidyl transferase region did not unveil any known mutations associated to the conferment of linezolid resistance. The presence of vanA did not confer resistance to vancomycin. Structural analyses into the Tn1546 transposon carrying the vanA gene revealed distinct genetic variations in the vanS, vanY and vanS-vanH intergenic region that could be associated to the atypical antibiotic resistance phenotypes of isolate 146. Finding from this study are suggestive of the occurrence of interspecies horizontal gene transfer and that similarities in genotypic characteristic may not necessarily correlate with actual antibiotic resistance pattern of E. gallinarum.

15.
Tropical Biomedicine ; : 589-593, 2016.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-630845

RESUMO

Members of the genus Kocuria are commonly found in the environment and they are also commensals of the mammalian skin and oropharynx mucosa. Human infections, although rare, are increasingly being reported recently suggesting that this genus has mostly been overlooked or misidentified. Its transmission route however, is still not known. We report here the isolation and identification of a Kocuria marina isolate from the lung of a wild urban rat (Rattus rattus diardii) caught at a wet market. The isolate was susceptible to most of the commonly used antibiotics. The finding suggests a possibility that rats could be a vector for K. marina.

16.
Tropical Biomedicine ; : 577-582, 2016.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-630843

RESUMO

The ability to acquire antibiotic resistance and virulence has propelled Enterococcus faecalis to become a major nosocomial pathogen. In Malaysia, data on the antibiotic resistance determinants and virulence of Enterococcus circulating strains are still scarce. This study aimed to assess the genotype of an E. faecalis isolate initially identified as Streptococcus uberis, examine the antibiotic resistance genotypes, analyze the genetic variations within Tn1546 and investigate the presence of virulence genes. The E. faecalis isolate was genetically characterized using multilocus sequence typing (MLST). Minimum inhibitory concentrations to vancomycin and teicoplanin were determined. Antibiotic resistance and other virulence genes were amplified using nucleic acid polymerase chain reaction. Mapping of the Tn1546 transposon was performed and compared to the prototype sequences. The E. faecalis isolate was found to have a MLST profile corresponding to sequence type 6. The isolate was resistant to teicoplanin but susceptible to vancomycin. Its genome consisted the vanA and vanC1 genes. Novel genetic variations in the vanS, vanS-vanH intergenic region and vanY genes were present and six virulence genes were detected. The detection of the vanC1 gene, thought to be non-transferable, suggests the potential emergence of inter-species enterococcal vanC1 gene transfer. The peculiar antibiotics resistance phenotype of this E. faecalis isolate could be associated to the novel genetic variations found. This study highlights the presence of E. faecalis belonging to the high-risk clonal complex with multiple virulence factors in Malaysia.

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