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Parasites & Vectors Jul 2024Toxoplasma gondii infection affects a significant portion of the global population, leading to severe toxoplasmosis and, in immunocompromised patients, even death....
BACKGROUND
Toxoplasma gondii infection affects a significant portion of the global population, leading to severe toxoplasmosis and, in immunocompromised patients, even death. During T. gondii infection, disruption of gut microbiota further exacerbates the damage to intestinal and brain barriers. Therefore, identifying imbalanced probiotics during infection and restoring their equilibrium can regulate the balance of gut microbiota metabolites, thereby alleviating tissue damage.
METHODS
Vimentin gene knockout (vim-/-) mice were employed as an immunocompromised model to evaluate the influence of host immune responses on gut microbiota balance during T. gondii infection. Behavioral experiments were performed to assess changes in cognitive levels and depressive tendencies between chronically infected vim-/- and wild-type (WT) mice. Fecal samples were subjected to 16S ribosomal RNA (rRNA) sequencing, and serum metabolites were analyzed to identify potential gut probiotics and their metabolites for the treatment of T. gondii infection.
RESULTS
Compared to the immunocompetent WT sv129 mice, the immunocompromised mice exhibited lower levels of neuronal apoptosis and fewer neurobehavioral abnormalities during chronic infection. 16S rRNA sequencing revealed a significant decrease in the abundance of probiotics, including several species of Lactobacillus, in WT mice. Restoring this balance through the administration of Lactobacillus murinus and Lactobacillus gasseri significantly suppressed the T. gondii burden in the intestine, liver, and brain. Moreover, transplantation of these two Lactobacillus spp. significantly improved intestinal barrier damage and alleviated inflammation and neuronal apoptosis in the central nervous system. Metabolite detection studies revealed that the levels of various Lactobacillus-related metabolites, including indole-3-lactic acid (ILA) in serum, decreased significantly after T. gondii infection. We confirmed that L. gasseri secreted much more ILA than L. murinus. Notably, ILA can activate the aromatic hydrocarbon receptor signaling pathway in intestinal epithelial cells, promoting the activation of CD8 T cells and the secretion of interferon-gamma.
CONCLUSION
Our study revealed that host immune responses against T. gondii infection severely disrupted the balance of gut microbiota, resulting in intestinal and brain damage. Lactobacillus spp. play a crucial role in immune regulation, and the metabolite ILA is a promising therapeutic compound for efficient and safe treatment of T. gondii infection.
Topics: Animals; Gastrointestinal Microbiome; Mice; Toxoplasma; Mice, Knockout; Brain Injuries; Probiotics; Brain; Lactobacillus; Disease Models, Animal; Immunocompromised Host; Toxoplasmosis; RNA, Ribosomal, 16S; Male; Intestines
PubMed: 38956725
DOI: 10.1186/s13071-024-06349-8 -
Parasites & Vectors Jul 2024The emergence of pyrethroid resistance has threatened the elimination of Triatoma infestans from the Gran Chaco ecoregion. We investigated the status and spatial...
BACKGROUND
The emergence of pyrethroid resistance has threatened the elimination of Triatoma infestans from the Gran Chaco ecoregion. We investigated the status and spatial distribution of house infestation with T. infestans and its main determinants in Castelli, a municipality of the Argentine Chaco with record levels of triatomine pyrethroid resistance, persistent infestation over 2005-2014, and limited or no control actions over 2015-2020.
METHODS
We conducted a 2-year longitudinal survey to assess triatomine infestation by timed manual searches in a well-defined rural section of Castelli including 14 villages and 234 inhabited houses in 2018 (baseline) and 2020, collected housing and sociodemographic data by on-site inspection and a tailored questionnaire, and synthetized these data into three indices generated by multiple correspondence analysis.
RESULTS
The overall prevalence of house infestation in 2018 (33.8%) and 2020 (31.6%) virtually matched the historical estimates for the period 2005-2014 (33.7%) under recurrent pyrethroid sprays. While mean peridomestic infestation remained the same (26.4-26.7%) between 2018 and 2020, domestic infestation slightly decreased from 12.2 to 8.3%. Key triatomine habitats were storerooms, domiciles, kitchens, and structures occupied by chickens. Local spatial analysis showed significant aggregation of infestation and bug abundance in five villages, four of which had very high pyrethroid resistance approximately over 2010-2013, suggesting persistent infestations over space-time. House bug abundance within the hotspots consistently exceeded the estimates recorded in other villages. Multiple regression analysis revealed that the presence and relative abundance of T. infestans in domiciles were strongly and negatively associated with indices for household preventive practices (pesticide use) and housing quality. Questionnaire-derived information showed extensive use of pyrethroids associated with livestock raising and concomitant spillover treatment of dogs and (peri) domestic premises.
CONCLUSIONS
Triatoma infestans populations in an area with high pyrethroid resistance showed slow recovery and propagation rates despite limited or marginal control actions over a 5-year period. Consistent with these patterns, independent experiments confirmed the lower fitness of pyrethroid-resistant triatomines in Castelli compared with susceptible conspecifics. Targeting hotspots and pyrethroid-resistant foci with appropriate house modification measures and judicious application of alternative insecticides with adequate toxicity profiles are needed to suppress resistant triatomine populations and prevent their eventual regional spread.
Topics: Animals; Triatoma; Pyrethrins; Insecticide Resistance; Argentina; Insecticides; Chagas Disease; Humans; Longitudinal Studies; Insect Vectors; Housing; Ecosystem; Insect Control
PubMed: 38956689
DOI: 10.1186/s13071-024-06366-7 -
JAMA Network Open Jul 2024
Topics: Humans; Chagas Disease; Male; Female; Health Knowledge, Attitudes, Practice; Adult; Middle Aged; Clinical Competence
PubMed: 38954417
DOI: 10.1001/jamanetworkopen.2024.19906 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Jun 2024To investigate the development and dynamic changes of cysts in the brain of mice following infection with different forms of , so as to provide insights into for...
OBJECTIVE
To investigate the development and dynamic changes of cysts in the brain of mice following infection with different forms of , so as to provide insights into for toxoplasmosis prevention and control.
METHODS
ICR mice at ages of 6 to 8 weeks, each weighing 20 to 25 g, were intraperitoneally injected with tachyzoites of the PRU strain at a dose of 1 × 10 tachyzoites per mouse, orally administered with cysts at a dose of 20 oocysts per mouse or oocysts at a dose of 200 oocysts per mouse for modeling chronic infection in mice, and the clinical symptoms and survival of mice were observed post-infection. Mice were orally infected with cysts at doses of 10 (low-dose group), 20 (medium-dose group), 40 cysts per mouse (high-dose group), and the effect of different doses of infections on the number of cysts was examined in the mouse brain. Mice were orally administered with cysts at a dose of 20 cysts per mouse, and grouped according to gender (female and male) and time points of infections (20, 30, 60, 90, 120, 150, 180 days post-infection), and the effects of gender and time points of infections on the number of cysts was examined in the mouse brain. In addition, mice were divided into the tachyzoite group (Group T), the first-generation cyst group (Group C1), the second-generation cyst group (Group C2), the third-generation cyst (Group C3) and the fourth-generation cyst group (Group C4). Mice in the Group T were intraperitoneally injected with tachyzoites at a dose of 1 × 10 tachyzoites per mouse, and the cysts were collected from the mouse brain tissues 30 days post-infection, while mice in the Group C1 were orally infected with the collected cysts at a dose of 30 cysts per mouse. Continuous passage was performed by oral administration with cysts produced by the previous generation in mice, and the effect of continuous passage on the number of cysts was examined in the mouse brain.
RESULTS
Following infection with tachyzoites, cysts and oocysts in mice, obvious clinical symptoms were observed on days 6 to 13 and mice frequently died on days 7 to 12. The survival rates of mice were 67.0%, 87.0% and 53.0%, and the mean numbers of cysts were (516.0 ± 257.2), (1 203.0 ± 502.0) and (581.0 ± 183.1) in the mouse brain ( = 11.94, < 0.01) on day 30 post-infection with tachyzoites, cysts and oocysts, respectively, and the numbers of cysts in the brain tissues were significantly lower in mice infected with tachyzoites and oocysts than in those infected with cysts (all values < 0.01). The survival rates of mice were 87.0%, 87.0% and 60.0%, and the mean numbers of cysts were (953.0 ± 355.5), (1 084.0 ± 474.3) and (1 113.0 ± 546.0) in the mouse brain in the low-, medium- and high-dose groups on day 30 post-infection, respectively ( = 0.42, > 0.05). The survival rates of male and female mice were 73.0% and 80.0%, and the mean numbers of cysts were (946.4 ± 411.4) and (932.1 ± 322.4) in the brain tissues of male and female mice, respectively ( = 1.63, > 0.05). Following continuous passage, the mean numbers of cysts were (516.0 ± 257.2), (1 203.0 ± 502.0), (896.8 ± 332.3), (782.5 ± 423.9) and (829.2 ± 306.0) in the brain tissues of mice in the T, C1, C2, C3 and C4 groups, respectively ( = 4.82, < 0.01), and the number of cysts was higher in the mouse brain in Group 1 than in Group T ( < 0.01). Following oral administration of 20 cysts in mice, cysts were found in the moues brain for the first time on day 20 post-infection, and the number of cysts gradually increased over time, peaked on days 30 and 90 post-infection and then gradually decreased; however, the cysts were still found in the mouse brain on day 180 post-infection.
CONCLUSIONS
There is a higher possibility of developing chronic infection in mice following infection with cysts than with oocysts or tachyzoites and the most severe chronic infection is seen following infection with cysts. The number of cysts does not correlate with the severity of chronic infection, and the number of cysts peaks in the mouse brain on days 30 and 90 post-infection.
Topics: Animals; Mice; Female; Male; Mice, Inbred ICR; Brain; Chronic Disease; Toxoplasmosis, Animal; Toxoplasma; Toxoplasmosis; Disease Models, Animal
PubMed: 38952318
DOI: 10.16250/j.32.1374.2024044 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Jun 2024To investigate the involvement of the high mobility group box protein B1 (HMGB1)-Toll-like receptor 2 (TLR2)/TLR4-nuclear factor κB (NF-κB) pathway in the intestinal...
OBJECTIVE
To investigate the involvement of the high mobility group box protein B1 (HMGB1)-Toll-like receptor 2 (TLR2)/TLR4-nuclear factor κB (NF-κB) pathway in the intestinal mucosal injury induced by infection, and to examine the effect of oxymatrine (OMT) on in mice.
METHODS
Forty SPF 4-week-old BALB/c mice were randomly divided into four groups, including the control group, infection group, glycyrrhizin (GA) group and OMT group. Each mouse was orally administered with 1 × 10 oocysts one week in the infection, GA and OMT groups following dexamethasone-induced immunosuppression to model intestinal infections in mice. Upon successful modeling, mice in the GA group were intraperitoneally injected with GA at a daily dose of 25.9 mL/kg for successive two weeks, and animals in the OMT group were orally administered OMT at a daily dose of 50 mg/kg for successive two weeks, while mice in the control group were given normal food and water. All mice were sacrificed two weeks post-treatment, and proximal jejunal tissues were sampled. The pathological changes of mouse intestinal mucosal specimens were observed using hematoxylin-eosin (HE) staining, and the mouse intestinal villous height, intestinal crypt depth and the ratio of intestinal villous height to intestinal crypt depth were measured. The occludin and zonula occludens protein 1 (ZO1) expression was determined in mouse intestinal epithelial cells using immunohistochemistry, and the relative expression of , , , myeloid differentiation primary response gene 88 () and was quantified in mouse jejunal tissues using quantitative real-time PCR (qPCR) assay.
RESULTS
HE staining showed that the mouse intestinal villi were obviously atrophic, shortened, and detached, and the submucosal layer of the mouse intestine was edematous in the infection group as compared with the control group, while the mouse intestinal villi tended to be structurally intact and neatly arranged in the GA and OMT groups. There were significant differences among the four groups in terms of the mouse intestinal villous height ( = 6.207, = 0.000 5), intestinal crypt depth ( = 6.903, = 0.000 3) and the ratio of intestinal villous height to intestinal crypt depth ( = 37.190, < 0.000 1). The mouse intestinal villous height was lower in the infection group than in the control group [(321.9 ± 41.1) μm vs. (399.5 ± 30.9) μm; = 4.178, < 0.01] and the GA group [(321.9 ± 41.1) μm vs. (383.7 ± 42.7) μm; = 3.130, < 0.01], and the mouse intestinal crypt depth was greater in the infection group [(185.0 ± 35.9) μm] than in the control group [(128.4 ± 23.6) μm] ( = 3.877, < 0.01) and GA group [(143.3 ± 24.7) μm] ( = 2.710, < 0.05). The mouse intestinal villous height was greater in the OMT group [(375.3 ± 22.9) μm] than in the infection group ( = 3.888, < 0.01), and there was no significant difference in mouse intestinal villous height between the OMT group and the control group ( = 1.989, > 0.05). The mouse intestinal crypt depth was significantly lower in the OMT group [(121.5 ± 27.3) μm] than in the infection group ( = 4.133, < 0.01), and there was no significant difference in mouse intestinal crypt depth between the OMT group and the control group ( = 0.575, > 0.05). The ratio of the mouse intestinal villous height to intestinal crypt depth was significantly lower in the infection group (1.8 ± 0.2) than in the control group (3.1 ± 0.3) ( = 10.540, < 0.01) and the GA group (2.7 ± 0.3) ( = 7.370, < 0.01), and the ratio of the mouse intestinal villous height to intestinal crypt depth was significantly higher in the OMT group (3.1 ± 0.2) than in the infection group ( = 15.020, < 0.01); however, there was no significant difference in the ratio of the mouse intestinal villous height to intestinal crypt depth between the OMT group and the control group ( = 0.404, > 0.05). Immunohistochemical staining showed significant differences among the four groups in terms of occludin ( = 28.031, < 0.000 1) and ZO1 expression ( = 14.122, < 0.000 1) in mouse intestinal epithelial cells. The proportion of positive occluding expression was significantly lower in mouse intestinal epithelial cells in the infection group than in the control group [(14.3 ± 4.5)% vs. (28.3 ± 0.5)%; = 3.810, < 0.01], and the proportions of positive occluding expression were significantly higher in mouse intestinal epithelial cells in the GA group [(30.3 ± 1.3)%] and OMT group [(25.8 ± 1.5)%] than in the infection group ( = 7.620 and 5.391, both values < 0.01); however, there was no significant differences in the proportion of positive occluding expression in mouse intestinal epithelial cells between the GA or OMT groups and the control group ( = 1.791 and 2.033, both values > 0.05). The proportion of positive ZO1 expression was significantly lower in mouse intestinal epithelial cells in the infection group than in the control group [(14.4 ± 1.8)% vs. (24.2 ± 2.8)%; = 4.485, < 0.01], and the proportions of positive ZO1 expression were significantly higher in mouse intestinal epithelial cells in the GA group [(24.1 ± 2.3)%] ( = 5.159, < 0.01) and OMT group than in the infection group [(22.5 ± 1.9)%] ( = 4.441, < 0.05); however, there were no significant differences in the proportion of positive ZO1 expression in mouse intestinal epithelial cells between the GA or OMT groups and the control group ( = 0.037 and 0.742, both values > 0.05). qPCR assay showed significant differences among the four groups in terms of ( = 21.980, < 0.000 1), ( = 20.630, < 0.000 1), ( = 17.000, = 0.000 6), ( = 8.907, = 0.000 5) and expression in mouse jejunal tissues ( = 8.889, = 0.000 7). The relative expression of [(5.97 ± 1.07) vs. (1.05 ± 0.07); = 6.482, < 0.05] 、 [(5.92 ± 1.29) vs. (1.10 ± 0.14); = 5.272, < 0.05] 、 [(5.96 ± 1.50) vs. (1.02 ± 0.03); = 4.644, < 0.05] 、 [(3.00 ± 1.26) vs. (1.02 ± 0.05); = 2.734, < 0.05] and [(2.33 ± 0.72) vs. (1.04 ± 0.06); = 2.665, < 0.05] was all significantly higher in mouse jejunal tissues in the infection group than in the control group. A significant reduction was detected in the relative expression of (0.63 ± 0.01), (0.42 ± 0.10), (0.35 ± 0.07), (0.70 ± 0.11) and (0.75 ± 0.01) in mouse jejunal tissues in the GA group relative to the control group ( = 8.629, 5.830, 11.500, 4.729 and 6.898, all values < 0.05), and the relative expression of , , , and significantly reduced in mouse jejunal tissues in the GA group as compared to the infection group ( = 7.052, 6.035, 4.084, 3.165 and 3.274, all values < 0.05). In addition, the relative expression of (1.14 ± 0.60), (1.00 ± 0.24), (1.14 ± 0.07), (0.96 ± 0.25) and N (1.12 ± 0.17) was significantly lower in mouse jejunal tissues in the OMT group than in the infection group ( = 7.059, 5.320, 3.510, 3.466 and 3.273, all values < 0.05); however, there were no significant differences between the OMT and control groups in terms of relative expression of , , , or in mouse jejunal tissues ( = 0.239, 0.518, 1.887, 0.427 and 0.641, all values > 0.05).
CONCLUSIONS
infection causes intestinal inflammatory responses and destruction of intestinal mucosal barrier through up-regulating of the HMGB1-TLR2/TLR4-NF-κB pathway. OMT may suppress the intestinal inflammation and repair the intestinal mucosal barrier through inhibiting the activity of the HMGB1-TLR2/TLR4-NF-κB pathway.
Topics: Animals; Cryptosporidiosis; Quinolizines; Mice, Inbred BALB C; Cryptosporidium parvum; Toll-Like Receptor 4; Mice; Toll-Like Receptor 2; NF-kappa B; Alkaloids; HMGB1 Protein; Signal Transduction; Male; Intestinal Mucosa; Matrines
PubMed: 38952315
DOI: 10.16250/j.32.1374.2024019 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Apr 2024Driven by international exchanges and climate changes, the invasion and spread of vector mosquitoes posed a new challenge to achieving global malaria elimination.... (Review)
Review
Driven by international exchanges and climate changes, the invasion and spread of vector mosquitoes posed a new challenge to achieving global malaria elimination. Taking the invasion of to exacerbate the malaria epidemic in Africa as an example, this article summarizes the current situation of global invasion, and estimates the potential risk of vector mosquitoes to unravel the difficulties and challenges in the global malaria elimination program, so as to provide insights into improved early earning and precision control of vector mosquito invasion across the world.
Topics: Malaria; Animals; Anopheles; Humans; Mosquito Vectors; Introduced Species; Disease Eradication
PubMed: 38952310
DOI: 10.16250/j.32.1374.2024043 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... May 2024The insecticide resistance is becoming increasingly severe in malaria vectors and has become one of the most important threats to global malaria elimination. Currently,...
The insecticide resistance is becoming increasingly severe in malaria vectors and has become one of the most important threats to global malaria elimination. Currently, malaria vectors not only have developed high resistance to conventional insecticides, including organochlorine, organophosphates, carbamates, and pyrethroids, but also have been resistant to recently used neonicotinoids and pyrrole insecticides. This article describes the current status of global insecticide resistance in malaria vectors and global insecticide resistance management strategies, analyzes the possible major challenges in the insecticide resistance management, and proposes the response actions, so as to provide insights into global insecticide resistance management and contributions to global malaria elimination.
Topics: Animals; Humans; Insect Vectors; Insecticide Resistance; Insecticides; Malaria; Mosquito Vectors
PubMed: 38952309
DOI: 10.16250/j.32.1374.2024088 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... May 2024The global malaria epidemic is still severe. Because of simple procedures, rapid detection and accuracy results, rapid diagnostic test (RDT) has become the most... (Review)
Review
The global malaria epidemic is still severe. Because of simple procedures, rapid detection and accuracy results, rapid diagnostic test (RDT) has become the most important and the most widely used diagnostic tool for malaria prevention and control. However, deletions in the RDT target histidine-rich protein 2/3 () genes may cause false-negative results of RDT, which has been included as one of the four biological threats to global malaria elimination. This article reviews the applications of RDT in the global malaria diagnosis, analyzes the threats and challenges caused by gene deletion, proposes methods for monitoring gene deletion, and summarizes the causes and countermeasures of negative RDT detections, so as to provide insights into consolidation of malaria elimination achievements in China and contributions to global malaria elimination.
Topics: Protozoan Proteins; Humans; Antigens, Protozoan; Plasmodium falciparum; Malaria, Falciparum; Gene Deletion; Diagnostic Tests, Routine; China; Rapid Diagnostic Tests
PubMed: 38952308
DOI: 10.16250/j.32.1374.2024089 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... May 2024Malaria is an infectious disease that seriously threatens human health. Currently, malaria control mainly depends on antimalarial chemotherapy. However, antimalarial... (Review)
Review
Malaria is an infectious disease that seriously threatens human health. Currently, malaria control mainly depends on antimalarial chemotherapy. However, antimalarial drug resistance is becoming increasingly severe, which poses a great challenge to malaria control, notably treatment of malaria. To address this challenge, there is a need to facilitate development of novel antimalarial drugs and innovation of treatment strategies, as well as reinforce surveillance and research on antimalarial drug resistance. This article reviews the main categories and use guidelines of current antimalarial agents, summarizes the current status and monitoring methods of antimalarial drug resistance, and proposes the response to antimalarial drug resistance, so as to provide insights into the use of antimalarial drugs and response to antimalarial drug resistance, and contribute to global malaria elimination.
Topics: Antimalarials; Humans; Drug Resistance; Malaria; Disease Eradication
PubMed: 38952307
DOI: 10.16250/j.32.1374.2024091 -
Zhongguo Xue Xi Chong Bing Fang Zhi Za... Apr 2024Malaria is one of the most serious mosquito-borne infectious diseases in the world. The global malaria control progress has stalled in recent years, which is largely due... (Review)
Review
Malaria is one of the most serious mosquito-borne infectious diseases in the world. The global malaria control progress has stalled in recent years, which is largely due to the biological threats from the malaria pathogen and the vector mosquitoes. This article provides an overview of biological threats to global malaria elimination, including antimalarial drug resistance, deletions in the malaria rapid diagnostic test target histidine-rich protein 2/3 () genes, vector insecticide resistance and emergence of invasive vector species, so as to provide insights into malaria and vector research and the formulation and adjustment of the malaria control and elimination strategy.
Topics: Animals; Malaria; Humans; Mosquito Vectors; Anopheles; Drug Resistance
PubMed: 38952306
DOI: 10.16250/j.32.1374.2024095