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1.
Virology ; 589: 109942, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38048647

ABSTRACT

Hantaan virus (HTNV) is responsible for hemorrhagic fever with renal syndrome (HFRS), primarily due to its ability to inhibit host innate immune responses, such as type I interferon (IFN-I). In this study, we conducted a transcriptome analysis to identify host factors regulated by HTNV nucleocapsid protein (NP) and glycoprotein. Our findings demonstrate that NP and Gc proteins inhibit host IFN-I production by manipulating the retinoic acid-induced gene I (RIG-I)-like receptor (RLR) pathways. Further analysis reveals that HTNV NP and Gc proteins target upstream molecules of MAVS, such as RIG-I and MDA-5, with Gc exhibiting stronger inhibition of IFN-I responses than NP. Mechanistically, NP and Gc proteins interact with tripartite motif protein 25 (TRIM25) to competitively inhibit its interaction with RIG-I/MDA5, suppressing RLR signaling pathways. Our study unveils a cross-talk between HTNV NP/Gc proteins and host immune response, providing valuable insights into the pathogenic mechanism of HTNV.


Subject(s)
Hantaan virus , Interferon Type I , Interferon Type I/metabolism , Hantaan virus/genetics , Hantaan virus/metabolism , Tripartite Motif Proteins/genetics , Tripartite Motif Proteins/metabolism , Signal Transduction , Immunity, Innate , DEAD Box Protein 58/genetics , DEAD Box Protein 58/metabolism
2.
Infect Med (Beijing) ; 2(3): 153-166, 2023 Sep.
Article in English | MEDLINE | ID: mdl-38073883

ABSTRACT

Mpox (monkeypox) virus (MPXV), which causes a mild smallpox-like disease, has been endemic in Africa for several decades, with sporadic cases occurring in other parts of the world. However, the most recent outbreak of mpox mainly among men that have sex with men has affected several continents, posing serious global public health concerns. The infections exhibit a wide spectrum of clinical presentation, ranging from asymptomatic infection to mild, severe disease, especially in immunocompromised individuals, young children, and pregnant women. Some therapeutics and vaccines developed for smallpox have partial protective and therapeutic effects against MPXV historic isolates in animal models. However, the continued evolution of MPXV has produced multiple lineages, leading to significant gaps in the knowledge of their pathogenesis that constrain the development of targeted antiviral therapies and vaccines. MPXV infections in various animal models have provided a central platform for identification and comparison of diseased pathogenesis between the contemporary and historic isolates. In this review, we discuss the susceptibility of various animals to MPXV, and describe the key pathologic features of rodent, rabbit and nonhuman primate models. We also provide application examples of animal models in elucidating viral pathogenesis and evaluating effectiveness of vaccine and antiviral drugs. These animal models are essential to understand the biology of MPXV contemporary isolates and to rapidly test potential countermeasures. Finally, we list some remaining scientific questions of MPXV that can be resolved by animal models.

3.
J Virol ; 97(10): e0102823, 2023 10 31.
Article in English | MEDLINE | ID: mdl-37772822

ABSTRACT

IMPORTANCE: Emerging vaccine-breakthrough severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants highlight an urgent need for novel antiviral therapies. Understanding the pathogenesis of coronaviruses is critical for developing antiviral drugs. Here, we demonstrate that the SARS-CoV-2 N protein suppresses interferon (IFN) responses by reducing early growth response gene-1 (EGR1) expression. The overexpression of EGR1 inhibits SARS-CoV-2 replication by promoting IFN-regulated antiviral protein expression, which interacts with and degrades SARS-CoV-2 N protein via the E3 ubiquitin ligase MARCH8 and the cargo receptor NDP52. The MARCH8 mutants without ubiquitin ligase activity are no longer able to degrade SARS-CoV-2 N proteins, indicating that MARCH8 degrades SARS-CoV-2 N proteins dependent on its ubiquitin ligase activity. This study found a novel immune evasion mechanism of SARS-CoV-2 utilized by the N protein, which is helpful for understanding the pathogenesis of SARS-CoV-2 and guiding the design of new prevention strategies against the emerging coronaviruses.


Subject(s)
Early Growth Response Protein 1 , Host Microbial Interactions , SARS-CoV-2 , Ubiquitin-Protein Ligases , Virus Replication , Humans , COVID-19/virology , Drug Discovery , Early Growth Response Protein 1/metabolism , SARS-CoV-2/growth & development , SARS-CoV-2/pathogenicity , Ubiquitin-Protein Ligases/metabolism , Ubiquitins/metabolism
4.
Front Microbiol ; 13: 1000322, 2022.
Article in English | MEDLINE | ID: mdl-36238596

ABSTRACT

Alongshan virus (ALSV) in the Jingmenvirus group within the family Flaviviridae is a newly discovered tick-borne virus associated with human disease, whose genome includes four segments and encodes four structural proteins (VP1a, VP1b, VP2, VP3, and VP4) and two non-structural proteins (NSP1 and NSP2). Here, we characterized the subcellular distribution and potential function of ALSV proteins in host cells. We found that viral proteins exhibited diverse subcellular distribution in multiple tissue-deriving cells and induced various morphological changes in the endoplasmic reticulum (ER), and NSP2, VP1b, VP2, and VP4 were all co-localized in the ER. The nuclear transfer and co-localization of VP4 and calnexin (a marker protein of ER), which were independent of their interaction, were unique to HepG2 cells. Expression of NSP1 could significantly reduce mitochondria quantity by inducing mitophagy. These findings would contribute to better understanding of the pathogenesis of emerging segmented flaviviruses.

6.
Nat Med ; 27(3): 434-439, 2021 03.
Article in English | MEDLINE | ID: mdl-33603240

ABSTRACT

The genus Orthonairovirus, which is part of the family Nairoviridae, includes the important tick-transmitted pathogens Crimean-Congo hemorrhagic fever virus and Nairobi sheep disease virus, as well as many other poorly characterized viruses found in ticks, birds and mammals1,2. In this study, we identified a new orthonairovirus, Songling virus (SGLV), from patients who reported being bitten by ticks in Heilongjiang Province in northeastern China. SGLV shared similar genomic and morphological features with orthonairoviruses and phylogenetically formed a unique clade in Tamdy orthonairovirus of the Nairoviridae family. The isolated SGLV induced cytopathic effects in human hepatoma cells in vitro. SGLV infection was confirmed in 42 hospitalized patients analyzed between 2017 and 2018, with the main clinical manifestations being headache, fever, depression, fatigue and dizziness. More than two-thirds (69%) of patients generated virus-specific antibody responses in the acute phase. Taken together, these results suggest that this newly discovered orthonairovirus is associated with human febrile illness in China.


Subject(s)
Fever/complications , Nairovirus/isolation & purification , Nairovirus/pathogenicity , Tick-Borne Diseases/virology , Virus Diseases/virology , Adult , Aged , China , Female , Fever/virology , Humans , Male , Middle Aged , Tick-Borne Diseases/complications , Virus Diseases/complications
7.
BMC Vet Res ; 15(1): 366, 2019 Oct 25.
Article in English | MEDLINE | ID: mdl-31653218

ABSTRACT

BACKGROUND: Toxoplasma gondii, an intracellular apicomplexan protozoan parasite, can infect almost all warm-blooded animals. The aim of the present study was to investigate T. gondii oocyst-driven infection in pigs, chickens and humans in Jilin province, northeastern China. RESULTS: The serum samples of pigs, chickens and humans were sampled and tested by indirect enzyme-linked immunosorbent assays (ELISAs) using dense granule antigen GRA7, oocyst-specific protein OWP8, and sporozoite-specific protein CCp5A, respectively. Results showed a prevalence of 16.7% by GRA7-ELISA, and 12.2% by OWP8- and CCp5A-ELISA in pigs; 10.4% by GRA7-ELISA, 13.5% by OWP8-ELISA, and 9.4% by CCp5A-ELISA in chickens; and 14.2% by GRA7-ELISA, 3.6% by OWP8-ELISA, and 3.0% by CCp5A-ELISA in humans. No significant differences were observed between T. gondii seroprevalence in pigs and chickens among the three antigens-based ELISAs (P > 0.05). However, there were significant differences between T. gondii seroprevalence rates in humans (P < 0.05). These findings demonstrated a low prevalence of T. gondii oocyst-driven infection in humans, a medium prevalence in pigs, and a high prevalence in chickens. CONCLUSIONS: The present study demonstrated that different oocyst-driven infection rates in different animal species, which would help to design effective strategies to prevent T. gondii transmission. To our knowledge, this is the first study to differentiate T. gondii infective forms in pigs, chickens and humans in China.


Subject(s)
Poultry Diseases/parasitology , Swine Diseases/parasitology , Toxoplasmosis/epidemiology , Animals , Antigens, Protozoan/blood , Chickens , China/epidemiology , Enzyme-Linked Immunosorbent Assay/methods , Enzyme-Linked Immunosorbent Assay/veterinary , Humans , Oocysts , Poultry Diseases/epidemiology , Protozoan Proteins/blood , Seroepidemiologic Studies , Swine , Swine Diseases/epidemiology , Toxoplasma/immunology , Toxoplasmosis, Animal/epidemiology
8.
Parasit Vectors ; 12(1): 450, 2019 Sep 12.
Article in English | MEDLINE | ID: mdl-31511049

ABSTRACT

BACKGROUND: Alongshan virus (ALSV) is a novel discovered segmented flavivirus associated with human febrile illness in northeastern China. Ixodes persulcatus is considered as a candidate vector of ALSV in the endemic regions. However, the role of domesticated animals in the circulation and transmission of ALSV have not been investigated. To evaluate the prevalence of ALSV infections in domesticated animals, viral RNA and viral specific antibodies were detected in sheep and cattle in Hulunbuir of northeastern Inner Mongolia. The findings contribute to the understanding of the ecology and transmission of ALSV among different natural hosts. METHODS: A total of 480 animal serum samples were collected in Hulunbuir of northeastern China in May, 2017. Viral specific antibodies were tested by indirect enzyme-linked immunosorbent assay (ELISA) with a purified E. coli recombinant capsid protein (VP2) of ALSV (strain H3) and further detected by viral neutralization test (VNT). RNA in serum samples were extracted and detected for ALSV sequence by quantitative real-time RT-PCR. ALSV RNA positive samples were used for virus isolation. RESULTS: ALSV-specific antibodies were detected in 9.2% (22/240) of examined sheep and 4.6% (11/240) of examined cattle by ELISA, while lower serological positivity with 4.2% (10/240) for sheep and 1.7% (4/240) for cattle was confirmed by VNT. In contrast, the prevalence of ALSV RNA was much higher, ranging from 26.3% (63/240) in sheep to 27.5% (66/240) in cattle. The partial S1 (NS5-like) and S3 (NS3-like) segments of ALSVs in sheep and cattle shared high identities of more than 98% to the human and tick isolates in the studied regions. CONCLUSIONS: These results suggest that the natural infection of ALSV can be found in sheep and cattle in the endemic regions.


Subject(s)
Antibodies, Viral/blood , Cattle Diseases/epidemiology , Disease Reservoirs/virology , Flaviviridae Infections/veterinary , Flaviviridae/isolation & purification , RNA, Viral/blood , Sheep Diseases/epidemiology , Animals , Cattle , Cattle Diseases/virology , China/epidemiology , Enzyme-Linked Immunosorbent Assay , Flaviviridae/genetics , Flaviviridae/immunology , Flaviviridae Infections/epidemiology , Flaviviridae Infections/virology , Neutralization Tests , Prevalence , Real-Time Polymerase Chain Reaction , Sheep , Sheep Diseases/virology
9.
N Engl J Med ; 380(22): 2116-2125, 2019 05 30.
Article in English | MEDLINE | ID: mdl-31141633

ABSTRACT

BACKGROUND: In 2017, surveillance for tickborne diseases in China led to the identification of a patient who presented to a hospital in Inner Mongolia with a febrile illness that had an unknown cause. The clinical manifestation of the illness was similar to that of tickborne encephalitis virus (TBEV) infection, but neither TBEV RNA nor antibodies against the virus were detected. METHODS: We obtained a blood specimen from the index patient and attempted to isolate and identify a causative pathogen, using genome sequence analysis and electron microscopy. We also initiated a heightened surveillance program in the same hospital to screen for other patients who presented with fever, headache, and a history of tick bites. We used reverse-transcriptase-polymerase-chain-reaction (RT-PCR) and cell-culture assays to detect the pathogen and immunofluorescence and neutralization assays to determine the levels of virus-specific antibodies in serum specimens from the patients. RESULTS: We found that the index patient was infected with a previously unknown segmented RNA virus, which we designated Alongshan virus (ALSV) and which belongs to the jingmenvirus group of the family Flaviviridae. ALSV infection was confirmed by RT-PCR assay in 86 patients from Inner Mongolia and Heilongjiang who presented with fever, headache, and a history of tick bites. Serologic assays showed that seroconversion had occurred in all 19 patients for whom specimens were available from the acute phase and the convalescent phase of the illness. CONCLUSIONS: A newly discovered segmented virus was found to be associated with a febrile illness in northeastern China. (Funded by the National Key Research and Development Program of China and the National Natural Science Foundation of China.).


Subject(s)
Communicable Diseases, Emerging/virology , Flaviviridae/isolation & purification , Tick-Borne Diseases/virology , Adult , Aged , Animals , China/epidemiology , Communicable Diseases, Emerging/epidemiology , Fatigue/etiology , Female , Fever/etiology , Flaviviridae/classification , Flaviviridae/genetics , Flaviviridae/ultrastructure , Headache/etiology , Humans , Male , Microscopy, Electron , Middle Aged , Phylogeny , Reverse Transcriptase Polymerase Chain Reaction , Symptom Assessment , Tick-Borne Diseases/complications , Tick-Borne Diseases/epidemiology , Ticks/virology
10.
Article in English | MEDLINE | ID: mdl-30956681

ABSTRACT

BACKGROUND: This study was to investigate the role of adenosine A2A receptors (A2AR) in inhibiting the effect of electroacupuncture (EA) on osteoclastogenesis in collagen-induced arthritis (CIA). METHODS: Wistar rats were divided into four groups: sham-control group, CIA-control group, CIA-EA group, and CIA-EA-SCH58261 (A2AR antagonist) group. We detected tumor necrosis factor-α (TNF-α), nuclear transcription factor-κB (NF-κB), receptor activator of NF-κB ligand (RANKL), protein kinase A (PKA), and extracellular regulatory protein kinase 1/2 (ERK1/2) in peripheral blood by ELISA. PKA, ERK1/2, and NF-κB in ankle joints were determined by western blotting. We evaluated the arthritis damage by histological examination and determined the number of osteoclasts by tartrate-resistant acid phosphatase (TRAP) staining. RESULTS: EA treatment downregulated the expression of TNF-α, RANKL, PKA, ERK1/2, and NF-κB in peripheral blood but increased the levels of PKA and ERK1/2 in ankle joints. Importantly, EA treatment reduced bone erosion as evidenced by the histological findings and inhibited osteoclastogenesis as revealed by TRAP staining. All these effects of the EA treatment were reversed by combining EA treatment with the A2AR antagonist SCH58261. CONCLUSION: Our data suggest that EA treatment activated A2AR. The effects of the A2AR antagonist SCH58261 suggest that the inhibition of osteoclast formation, the inhibition of TNF-α, RANKL, and NF-κB expression, and the increase of ERK1/2 are all dependent on this EA-induced A2AR activation. It is therefore likely that these pathways with clearly defined roles in inflammation and bone erosion are at least partially involved in the mediation of the inhibition of synovitis and osteoclast formation induced by EA.

11.
Transbound Emerg Dis ; 65(6): 1733-1739, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29992783

ABSTRACT

Lymphocytic choriomeningitis virus (LCMV) is a rodent-borne arenavirus that is considered a neglected cause of neurologic diseases in humans. In this study, we described genomic characterization of newly isolated LCMVs in Haemaphysalis longicornis, Dermacentor nuttalli, Dermacentor silvarum and Ixodes persulcatus in Jilin Province, northeastern China. The complete sequences of the small (S) and large (L) segments of LCMVs in ticks contained 3,375 and 7,235-7,241 nucleotides, respectively. Sequence comparison showed 82.1%-86.0% identity of S segment with other lineage I strains at the nucleotide level and 91.2%-97.5% at the deduced amino acid level, while a lower identity was observed in the L segment at both nucleotide (75.4%-82.2%) and amino acid (82.4%-93.4%) levels. Phylogenetic analysis grouped the tick LCMVs together with the lineage I strains, but in an isolated cluster with a high bootstrap value. Bayesian analysis indicated that the molecular evolutionary rate was estimated to be 3.3 × 10-4 substitutions/site/year for the S segment and 6.3 × 10-4 substitutions/site/year for the L segment, and the time to most recent common ancestor was 1980 and 1970 years ago, respectively, showing that tick LCMVs were predicted to originate between 1970s and 1980s. A long evolutionary history and high prevalence of LCMV in H. longicornis were found compared to other tick species. This study represented the first report on isolation of LCMV in China, showing that LCMV is circulating among ticks in Jilin Province, but the role of ticks in the epidemiology of LCMV remains to be explored.


Subject(s)
Arachnid Vectors/virology , Genome, Viral/genetics , Lymphocytic choriomeningitis virus/genetics , Lymphocytic choriomeningitis virus/isolation & purification , Ticks/virology , Animals , Bayes Theorem , China/epidemiology , Host Microbial Interactions , Phylogeny
12.
Ticks Tick Borne Dis ; 9(4): 836-839, 2018 05.
Article in English | MEDLINE | ID: mdl-29567144

ABSTRACT

Novel circular single-stranded DNA (ssDNA) genomes have been found in various animals using high-throughput sequencing techniques. In this study, two circular ssDNA genomes were detected in adult ticks from northeastern China by Solexa sequencing and PCR. The two sequences shared a similar genomic organization to circoviruses, with genomes of 1936 bp (TiCV-1) and 1812 bp (TiCV-2), each including two major open read frames (ORFs), ORF1 and ORF2, encoding putative replicase and capsid proteins, respectively. The potential stem-loop structure of a circovirus was predicted in the intergenic region between the two ORFs. Sequence comparison showed that the genome of TiCV-2 was almost the same as that of TiCV-1, except for two deletions and several mutations, and they had a high identity of 71.3-72.9% with Raven circovirus. The infection rates of circoviruses were calculated by the maximum likelihood estimation as 3.2% (95% CI, 1.9-5.2%) for TiCV-1 in the investigated Haemaphysalis longicornis, and 1.2% (95% CI, 0.2-4.0%) for TiCV-2 in Ixodes crenulatus from Yichun of Heilongjiang Province. These results indicate that the two sequences are distantly related to known circovirus genomes and may represent novel species in the family Circoviridae.


Subject(s)
Circovirus/genetics , DNA, Viral/genetics , Dermacentor/virology , Genome, Viral , Ixodes/virology , Animals , Animals, Wild/parasitology , China/epidemiology , Circovirus/isolation & purification , Cloning, Molecular , DNA, Intergenic , Forests , Genomics , High-Throughput Nucleotide Sequencing , Metagenomics , Open Reading Frames , Phylogeny , Polymerase Chain Reaction , Tick Infestations/epidemiology
13.
Parasit Vectors ; 11(1): 28, 2018 01 09.
Article in English | MEDLINE | ID: mdl-29316950

ABSTRACT

BACKGROUND: Diarrhea caused by opportunistic intestinal protozoa is a common problem in HIV infection. We aimed to establish the prevalence of Cryptosporidium, misrosporidia, and Isospora in HIV-infected people using a systematic review and meta-analysis, which is central to developing public policy and clinical services. METHODS: We searched PubMed, ScienceDirect, Google Scholar, Embase, Chinese Web of Knowledge, Wanfang, and Chongqing VIP databases for studies reporting Cryptosporidium, microsporidia, or Isospora infection in HIV-infected people. We extracted the numbers of people with HIV and protozoa infection, and estimated the pooled prevalence of parasite infection by a random effects model. RESULTS: Our research identified 131 studies that reported Cryptosporidium, microsporidia, and Isospora infection in HIV-infected people. We estimated the pooled prevalence to be 14.0% (3283/43,218; 95% CI: 13.0-15.0%) for Cryptosporidium, 11.8% (1090/18,006; 95% CI: 10.1-13.4%) for microsporidia, and 2.5% (788/105,922; 95% CI: 2.1-2.9%) for Isospora. A low prevalence of microsporidia and Isospora infection was found in high-income countries, and a high prevalence of Cryptosporidium and Isospora infection was found in sub-Saharan Africa. We also detected a high prevalence of Cryptosporidium, microsporidia, and Isospora infection in patients with diarrhea. Sensitivity analysis showed that three studies significantly affect the prevalence of Isospora, which was adjusted to 5.0% (469/8570; 95% CI: 4.1-5.9%) by excluding these studies. CONCLUSIONS: Our findings suggest that HIV-infected people have a high prevalence of Cryptosporidium, microsporidia, and Isospora infection in low-income countries and patients with diarrhea, especially in sub-Saharan Africa, reinforcing the importance of routine surveillance for opportunistic intestinal protozoa in HIV-infected people.


Subject(s)
Cryptosporidiosis/epidemiology , HIV Infections/complications , Isosporiasis/epidemiology , Microsporidiosis/epidemiology , Diarrhea/epidemiology , Diarrhea/parasitology , Global Health , Humans , Prevalence
15.
Front Microbiol ; 8: 389, 2017.
Article in English | MEDLINE | ID: mdl-28337191

ABSTRACT

Toxoplasma gondii has been suggested as an important opportunistic pathogen in immunocompromised patients. We conducted a global meta-analysis to assess the prevalence and odds ratios (ORs) of T. gondii infection in immunocompromised individuals. Electronic databases were reviewed for T. gondii infection in HIV/AIDS patients, cancer patients, and transplant recipients, and meta-analyses were conducted to calculate overall estimated prevalence and ORs using random or fixed-effects models. Totally, 72 eligible studies were included. The estimated pooled prevalence of T. gondii infection in immunocompromised patients and the control was 35.9 and 24.7% (p < 0.001), with an OR of 2.24, i.e., 42.1 and 32.0% for HIV/AIDS patients and the control (p < 0.05), 26.0 and 12.1% for cancer patients and the control (p < 0.001), and 42.1 and 34.5% for transplant recipients and the control (p > 0.05), whose estimated pooled ORs were 1.92 (95% CI, 1.44-2.55), 2.89 (95% CI, 2.36-3.55), and 1.51 (95% CI, 1.16-1.95), respectively. This study is the first to demonstrate that the immunocompromised patients are associated with higher odds of T. gondii infection, and appropriate prevention and control measures are highly recommended for these susceptible populations.

16.
Lancet HIV ; 4(4): e177-e188, 2017 04.
Article in English | MEDLINE | ID: mdl-28159548

ABSTRACT

BACKGROUND: Worldwide, 30% of the world's population have antibodies to the intracellular protozoan parasite Toxoplasma gondii and about 36·7 million people are infected with HIV, but little is known about the prevalence of co-infection with T gondii and HIV. We aimed to characterise the epidemiology and burden of T gondii co-infection in people with HIV infection. METHODS: In this systematic review and meta-analysis, we searched PubMed, Embase, Google Scholar, ScienceDirect, Chinese Web of Knowledge, Wanfang, and Chongqing VIP databases for studies reporting T gondii infection in HIV-infected people from inception to Feb 29, 2016. Studies were included if they investigated people with HIV infection and presented data that allowed us to establish the prevalence of T gondii infection. We excluded reviews, repeated studies, or animal studies, as well as studies that provided the final results without raw data, had a sample size less than 30 people, had unclear diagnostic methods of T gondii infection, or that included populations with increased risk of T gondii infection. We extracted the numbers of patients with HIV infection and T gondii co-infection from the identified studies. We estimated pooled prevalence of T gondii infection in HIV-infected people by a random-effects model, and evaluated its overall infection burden worldwide. FINDINGS: Our search identified 7843 records and after removal of duplicates and initial screening, we reviewed 312 studies in full. Of these articles, 238 were excluded, leaving 74 studies that included 25 989 HIV-infected people from 34 countries. Of these people, 7326 had T gondii co-infection and we estimated the pooled worldwide prevalence of T gondii infection to be 35·8% (95% CI 30·8-40·7). 2353 of 8837 of people in Asia and the Pacific had co-infection with T gondii and HIV (prevalence 25·1%, 95% CI 19·0-31·2), and prevalence was low in this region compared with that in sub-Saharan Africa (44·9%, 32·3-57·5, 2129/5686; odds ratio [OR] 0·61), Latin America and the Caribbean (49·1%, 27·9-70·4, 510/980; OR 0·33), and North Africa and the Middle East (60·7%, 24·1-97·3, 245/439; OR 0·29). 1561 of 3780 people in low-income countries had co-infection (54·7%, 95% CI 35·8-73·5), which was higher than in middle-income countries (34·2%, 27·4-40·9, 3632/11 540; OR 1·53) and high-income countries (26·3%, 20·4-32·2, 2133/10 669; OR 2·82). Worldwide, we calculated that there were roughly 13 138 600 (95% CI 11 303 600-14 936 900) cases of T gondii co-infection in HIV-infected people, with 87·1% in sub-Saharan Africa (11 449 500 cases, 95% CI 8 236 500-14 662 500). INTERPRETATION: Our findings suggest that people with HIV infection have a very high burden of T gondii infection, especially in sub-Saharan Africa, and emphasise the importance of routine surveillance for T gondii infection in all HIV-infected people. FUNDING: National Natural Science Foundation and the Special Fund for Agro-scientific Research in the Public Interest in China.


Subject(s)
Coinfection/epidemiology , Cost of Illness , HIV Infections/complications , Toxoplasmosis/complications , Toxoplasmosis/epidemiology , Adolescent , Africa South of the Sahara/epidemiology , Caribbean Region/epidemiology , Female , HIV Infections/epidemiology , HIV Infections/virology , Humans , Latin America/epidemiology , Prevalence , Toxoplasma/isolation & purification , Toxoplasmosis/parasitology
17.
Parasitol Res ; 115(9): 3419-24, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27150970

ABSTRACT

Toxoplasma gondii uses a unique mechanism to fulfill its asexual life cycles by which the parasite can infect all the warm-blooded animals including humans. Mitogen-activated protein kinase (MAPK) or extracellular signal-regulated kinase (ERK) pathway widely existed in eukaryotic cells mediates the conversion of environmental stimuli to intracellular events such as proliferation and differentiation. Their counterparts have been identified in Apicomplexan parasites such as ERK7 in T. gondii. To confirm whether the unique mechanism of T. gondii is relevant to MAPK/ERK member, we created a mutant (ΔTgERK7) in GT1 tachyzoites using double homologous recombination method. Our results of virulence evaluation showed 100 % survival of all the ΔTgERK7-infected mice until 35 days post-challenge compared to no survival in wild-type GT1-infected group (10.6 ± 0.34 days). Furthermore, lower parasite loads were detected in the peritoneal fluid of ΔTgERK7-infected mice (P < 0.05). To ensure whether or not ERK7 gene knockout leads to the growth deficiency of T. gondii, the intracellular proliferation of ΔTgERK7 was also examined in vitro. Our data indicated that the proliferation of ΔTgERK7 parasites was significantly prolonged in comparison with wild-type GT1 tachyzoites (P < 0.05). Therefore, we concluded that TgERK7 is important for the intracellular proliferation of T. gondii, which further emphasized that MAPK/ERK derived from T. gondii participates in the regulation of the asexual life cycles to ensure the survival and reinfections of this parasite.


Subject(s)
Extracellular Signal-Regulated MAP Kinases/metabolism , Protozoan Proteins/metabolism , Toxoplasma/cytology , Toxoplasma/genetics , Toxoplasmosis/parasitology , Animals , Cell Differentiation , Cell Proliferation , Extracellular Signal-Regulated MAP Kinases/genetics , Humans , Life Cycle Stages , Mice , Protozoan Proteins/genetics , Toxoplasma/classification
18.
Foodborne Pathog Dis ; 13(2): 88-92, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26682614

ABSTRACT

Toxoplasma gondii is prevalent in humans and animals worldwide. The present study aimed to determine the genetic diversity of T. gondii isolates from pigs in Jilin province, northeastern China. A total of 100 DNA samples were extracted from the hilar lymph nodes of slaughtered pigs, and 9 (9.0%, 95% confidence interval: 3.4-14.6%) were detected positive for T. gondii B1 gene by a nested polymerase chain reaction (PCR). The positive DNA samples were typed at 11 genetic markers, including 10 nuclear loci (SAG1, 5'-SAG2, and 3'-SAG2, alternative SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, and PK1) and an apicoplast locus (Apico) using the multilocus PCR-restriction fragment length polymorphism technology. Only three isolates were completely typed at all loci, showing that they all belonged to the clonal type I. One isolate was typed at five loci, including 5' +3'-SAG2, SAG2, SAG3, GRA6, and L358, revealing the possible clonal type I. This is the first report of the genetic characterization of T. gondii isolates in pigs in Jilin province, northeastern China, which has implications for better understanding the population structure of T. gondii infection in China.


Subject(s)
DNA, Protozoan/analysis , Genetic Variation , Swine/microbiology , Toxoplasma/genetics , Abattoirs , Animals , China/epidemiology , Genetic Markers , Lymph Nodes/parasitology , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Prevalence , Swine Diseases/epidemiology , Swine Diseases/parasitology , Toxoplasma/isolation & purification , Toxoplasmosis, Animal/epidemiology , Toxoplasmosis, Animal/parasitology
19.
Lancet Infect Dis ; 15(10): 1226-1235, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26364132

ABSTRACT

Human sparganosis is a food borne zoonosis caused by the plerocercoid larvae (spargana) of various diphyllobothroid tapeworms of the genus Spirometra. Human infections are acquired by ingesting the raw or undercooked meat of snakes or frogs, drinking untreated water, or using raw flesh in traditional poultices. More than 1600 cases of sparganosis have been documented worldwide, mostly in east and southeast Asia. Sporadic cases have been reported in South America, Europe, and Africa, and several cases have been described in travellers returning from endemic regions. Epidemiological data suggest that the increased effect of sparganosis on human health is because of greater consumption of raw meat of freshwater frogs and snakes. This Review provides information about the Spirometra parasites and their lifecycles, summarises clinical features, diagnosis, and treatment of human sparganosis, and describes geographical distribution and infection characteristics of Spirometra parasites in host animals.


Subject(s)
Foodborne Diseases/epidemiology , Neglected Diseases/epidemiology , Sparganosis/epidemiology , Sparganum/isolation & purification , Spirometra/physiology , Zoonoses/epidemiology , Africa/epidemiology , Animals , Asia, Southeastern/epidemiology , Europe/epidemiology , Foodborne Diseases/diagnosis , Foodborne Diseases/drug therapy , Foodborne Diseases/pathology , Humans , Neglected Diseases/diagnosis , Neglected Diseases/drug therapy , Neglected Diseases/pathology , South America/epidemiology , Sparganosis/diagnosis , Sparganosis/drug therapy , Sparganosis/pathology , Topography, Medical , Travel , Zoonoses/diagnosis , Zoonoses/drug therapy , Zoonoses/pathology
20.
Parasitol Int ; 64(6): 576-8, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26292258

ABSTRACT

Toxoplasma gondii can infect almost warm-blooded animals, including humans. Limited information about T. gondii infection in wild waterfowls is available in China. The present study was conducted to determine prevalence and genotype T. gondii infection in 11 wild waterfowl species in Jilin Province, northeastern China. A total of 249 wild waterfowls were sampled between April and July 2013 from Jilin Province, and the tissue samples were collected for the detection of T. gondii by a semi-nested PCR targeting the B1 gene. The positive samples were genotyped at 11 genetic markers (SAG1, 5'- and 3'-SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and Apico) using multilocus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. The overall prevalence of T. gondii in the wild waterfowls was 7.2% (18/249, 95% confidence interval [CI] 4.0-10.4), with the highest prevalence (22.0%, 95% CI 10.5-33.5) in Anas formosa, followed by Anas platyrhynchos (20.0%, 95% CI 6.0-44.0), Falcated teal (12.5%, 95% CI 0.0-35.4), and Fulica atra (4.0%, 95% CI 0.0-11.7). Of 18 positive samples, only 2 samples (TgWfjl1 and TgWfjl2) were genotyped completely, and one genotype, namely ToxoDB #9, was revealed. The result of this survey has implications for better understanding of the genetic diversity of T. gondii in China. This is the first report of prevalence and genotypic characterization of T. gondii in wild waterfowls in northeastern China.


Subject(s)
Anseriformes/parasitology , Bird Diseases/epidemiology , Toxoplasma/classification , Toxoplasmosis, Animal/epidemiology , Animals , Bird Diseases/parasitology , China/epidemiology , DNA, Protozoan/genetics , Genetic Variation/genetics , Polymerase Chain Reaction/veterinary , Polymorphism, Restriction Fragment Length , Toxoplasma/genetics , Toxoplasma/isolation & purification , Toxoplasmosis, Animal/parasitology
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