Background:The genus Rickettsia in the order Rickettsiales(Alphaproteobacteria)consists of gram-negative obligate intracellular bacteria that infect a wide range of hosts.Epidemiological studies on the occurrence of R...Background:The genus Rickettsia in the order Rickettsiales(Alphaproteobacteria)consists of gram-negative obligate intracellular bacteria that infect a wide range of hosts.Epidemiological studies on the occurrence of Rickettsia spp.and their associated tick vectors are essential to understand their distribution,host range,and transmission mechanisms in nature.This is particularly relevant within the One Health framework,which emphasizes the interconnectedness of animal,human,and environmental health.Methods:To investigate the presence of Rickettsia spp.in dogs and their ticks in Malawi,a molecular survey was conducted.A total of 209 dog blood and 259 tick samples of the species Haemaphysalis elliptica(n=16)and Rhipicephalus linnaei(n=243)were screened using real-time quantitative PCR(qPCR)targeting the citrate synthase(gltA)gene.Positive samples were further characterized via the conventional PCR and Sanger sequencing of gltA and the outer membrane protein A(ompA)genes.Results:Rickettsia DNA was not detected in any dog samples.However,the detection rates in R.linnaei and H.elliptica were 2.5%(n=6)and 6.3%(n=1),respectively.The obtained sequences showed 100% identity with Rickettsia conorii subsp.conorii(n=4),99%-100% with Rickettsia massiliae(n=2),and 100% with Rickettsia rhipicephali(n=1).Phylogenetic analysis clustered these sequences with the corresponding sequences of R.conorii subsp.conorii,R.massiliae,and R.rhipicephali reported from other countries in both gltA and ompA gene-based phylogenetic trees.The detection of R.massiliae and R.rhipicephali in southern Africa suggests expansion of the geographical distribution of these potentially zoonotic Rickettsia species.Conclusion:This is the first report of Rickettsia species detection in ticks collected from dogs in Malawi.The findings highlight the need for further surveillance,including humans and other animals,to better assess the public and veterinary health risks.Public engagement is needed to raise awareness on the role of dogs and their ticks in the transmission of Rickettsia within the One Health approach.展开更多
GLOBAL CONTEXT OF CHIKUNGUNYA As of August 12,2025,Guangdong province has reported over 10,000 confirmed chikungunya cases within just one month,with most cases concentrated in Foshan city.This rapid and unexpected re...GLOBAL CONTEXT OF CHIKUNGUNYA As of August 12,2025,Guangdong province has reported over 10,000 confirmed chikungunya cases within just one month,with most cases concentrated in Foshan city.This rapid and unexpected resurgence has drawn significant attention from health authorities both within China and internationally,raising substantial public health concerns.展开更多
The discovery of the hazardous effects associated with the polymer additives 1,3-diphenyl guanidine(DPG)and 1,3-di-o-tolylguanidine(DTG)has prompted the need for biomonitoring studies to detect human exposure.However,...The discovery of the hazardous effects associated with the polymer additives 1,3-diphenyl guanidine(DPG)and 1,3-di-o-tolylguanidine(DTG)has prompted the need for biomonitoring studies to detect human exposure.However,limited information is available about their metabolism.To address this gap,this study investigates the Phase I and II in-vitro biotransformation of both chemicals using human liver microsomes and cytosol.The samples were analyzed using liquid chromatography coupled to high resolution-(tandem)mass spectrometry through suspect(of in-silico predicted metabolites)and nontarget screening.The analysis revealed four Phase I and two Phase II metabolic products for both DPG and DTG.Hydroxylation of the benzene ring led to the tentative identification of mono-and dihydroxylated metabolites.Subsequent Phase I deamination followed by oxidation resulted in the formation of hydroxy-phenylurea and an intramolecular cyclization resulted in the formation of hydroxycyclic products.Furthermore,N-glucuronidation and O-glucuronidation products were identified for the first time.After performing urinalysis,DPG and DTG could be quantified in the 0.020.23μg L^(−1) range,and DPG-227(mono-hydroxylated DPG)was estimated to be present at ca.0.010.10μg L^(−1) range,using DPG response as quantification surrogate.Finally,toxicity assessment using an in-silico tool indicated the need to consider these human metabolites in(eco)toxicological assessments,as they may have the same or even greater effects on humans and the environment.展开更多
Invasive raccoons(Procyon lotor)naturalized in Hokkaido,Japan,potentially spreading infectious diseases.Canine distemper virus infection is a serious epizootic disease,for which the raccoon is one of the hosts.We inve...Invasive raccoons(Procyon lotor)naturalized in Hokkaido,Japan,potentially spreading infectious diseases.Canine distemper virus infection is a serious epizootic disease,for which the raccoon is one of the hosts.We investigated the virus’s prevalence in Hokkaido’s wild raccoons,using 611 serum samples collected from captured raccoons in 2007–2012,2021,and 2022.Higher seropositivity rateswere confirmed in 2007(32.7%),2021(46.4%),and 2022(46.8%)than in 2008–2012(0.00%–6.06%),suggesting the occurrence of an epidemic in 2007,2021,and 2022 and its disappearance in 2008–2012.However,the infection status has recently changed,with high seropositivity rates consecutively confirmed in 2021 and 2022.Logistic regression analysis was performed to investigate the relationships among the catch per unit effort(an index of animal population density),host and environmental factors,and antibody status.The catch per unit effort correlated with seropositivity in 2007.As for environmental factors,the forest area ratio had a weak influence on seroprevalence in 2007;however,the residential area ratio had a clear influence on seroprevalence in 2021 and 2022.The epidemic occurred in forested areas in 2007;nonetheless,recent raccoon population growth and habitat expansionmay have caused widespread infections even around residential areas in 2021 and 2022.Continuous monitoring of the infection and reinforcement of raccoon control programs are necessary to avoid serious damage through disease transmission to sympatric native raccoon dog(Nyctereutes procyonoides)and fox(Vulpes vulpes)populations,as well as health consequences for domestic dogs(Canis familiaris).展开更多
基金supported in part by the Japan Society for the Promotion of Science(JSPS)KAKENHI(grant numbers JP23K23770,JP24KK0133,and JP25K02166)the Japan Agency for Medical Research and Developmen(AMED)(grant numbers JP18jm0510001 and JP23wm0225034)JST SPRING(grant number JPMJSP2119).
文摘Background:The genus Rickettsia in the order Rickettsiales(Alphaproteobacteria)consists of gram-negative obligate intracellular bacteria that infect a wide range of hosts.Epidemiological studies on the occurrence of Rickettsia spp.and their associated tick vectors are essential to understand their distribution,host range,and transmission mechanisms in nature.This is particularly relevant within the One Health framework,which emphasizes the interconnectedness of animal,human,and environmental health.Methods:To investigate the presence of Rickettsia spp.in dogs and their ticks in Malawi,a molecular survey was conducted.A total of 209 dog blood and 259 tick samples of the species Haemaphysalis elliptica(n=16)and Rhipicephalus linnaei(n=243)were screened using real-time quantitative PCR(qPCR)targeting the citrate synthase(gltA)gene.Positive samples were further characterized via the conventional PCR and Sanger sequencing of gltA and the outer membrane protein A(ompA)genes.Results:Rickettsia DNA was not detected in any dog samples.However,the detection rates in R.linnaei and H.elliptica were 2.5%(n=6)and 6.3%(n=1),respectively.The obtained sequences showed 100% identity with Rickettsia conorii subsp.conorii(n=4),99%-100% with Rickettsia massiliae(n=2),and 100% with Rickettsia rhipicephali(n=1).Phylogenetic analysis clustered these sequences with the corresponding sequences of R.conorii subsp.conorii,R.massiliae,and R.rhipicephali reported from other countries in both gltA and ompA gene-based phylogenetic trees.The detection of R.massiliae and R.rhipicephali in southern Africa suggests expansion of the geographical distribution of these potentially zoonotic Rickettsia species.Conclusion:This is the first report of Rickettsia species detection in ticks collected from dogs in Malawi.The findings highlight the need for further surveillance,including humans and other animals,to better assess the public and veterinary health risks.Public engagement is needed to raise awareness on the role of dogs and their ticks in the transmission of Rickettsia within the One Health approach.
文摘GLOBAL CONTEXT OF CHIKUNGUNYA As of August 12,2025,Guangdong province has reported over 10,000 confirmed chikungunya cases within just one month,with most cases concentrated in Foshan city.This rapid and unexpected resurgence has drawn significant attention from health authorities both within China and internationally,raising substantial public health concerns.
基金funded by the Spanish Agencia Estatal de Investigacion MCIN/AEI/10.13039/501100011033(PID2020-117686RB-C32,CNS2024-154426 and TED2021-129200B-C41(co)funded by the EU through NextGeneration EU/PRTR funds)Conselleria de Cultura de Galicia,Educacion e Universidades(ED481A-2020/258,ED431C-2025/21and ED481B-2025/042).
文摘The discovery of the hazardous effects associated with the polymer additives 1,3-diphenyl guanidine(DPG)and 1,3-di-o-tolylguanidine(DTG)has prompted the need for biomonitoring studies to detect human exposure.However,limited information is available about their metabolism.To address this gap,this study investigates the Phase I and II in-vitro biotransformation of both chemicals using human liver microsomes and cytosol.The samples were analyzed using liquid chromatography coupled to high resolution-(tandem)mass spectrometry through suspect(of in-silico predicted metabolites)and nontarget screening.The analysis revealed four Phase I and two Phase II metabolic products for both DPG and DTG.Hydroxylation of the benzene ring led to the tentative identification of mono-and dihydroxylated metabolites.Subsequent Phase I deamination followed by oxidation resulted in the formation of hydroxy-phenylurea and an intramolecular cyclization resulted in the formation of hydroxycyclic products.Furthermore,N-glucuronidation and O-glucuronidation products were identified for the first time.After performing urinalysis,DPG and DTG could be quantified in the 0.020.23μg L^(−1) range,and DPG-227(mono-hydroxylated DPG)was estimated to be present at ca.0.010.10μg L^(−1) range,using DPG response as quantification surrogate.Finally,toxicity assessment using an in-silico tool indicated the need to consider these human metabolites in(eco)toxicological assessments,as they may have the same or even greater effects on humans and the environment.
文摘Invasive raccoons(Procyon lotor)naturalized in Hokkaido,Japan,potentially spreading infectious diseases.Canine distemper virus infection is a serious epizootic disease,for which the raccoon is one of the hosts.We investigated the virus’s prevalence in Hokkaido’s wild raccoons,using 611 serum samples collected from captured raccoons in 2007–2012,2021,and 2022.Higher seropositivity rateswere confirmed in 2007(32.7%),2021(46.4%),and 2022(46.8%)than in 2008–2012(0.00%–6.06%),suggesting the occurrence of an epidemic in 2007,2021,and 2022 and its disappearance in 2008–2012.However,the infection status has recently changed,with high seropositivity rates consecutively confirmed in 2021 and 2022.Logistic regression analysis was performed to investigate the relationships among the catch per unit effort(an index of animal population density),host and environmental factors,and antibody status.The catch per unit effort correlated with seropositivity in 2007.As for environmental factors,the forest area ratio had a weak influence on seroprevalence in 2007;however,the residential area ratio had a clear influence on seroprevalence in 2021 and 2022.The epidemic occurred in forested areas in 2007;nonetheless,recent raccoon population growth and habitat expansionmay have caused widespread infections even around residential areas in 2021 and 2022.Continuous monitoring of the infection and reinforcement of raccoon control programs are necessary to avoid serious damage through disease transmission to sympatric native raccoon dog(Nyctereutes procyonoides)and fox(Vulpes vulpes)populations,as well as health consequences for domestic dogs(Canis familiaris).
