Journal of Tropical Medicine最新文献

Cutaneous leishmaniasis (CL), a neglected tropical disease, is an important health problem in Fars Province, southern Iran. Fars, the fourth most populous Province in Iran, is the center of both anthroponotic and zoonotic cutaneous leishmaniasis (ZCL). Rodents, the reservoir of Leishmania major, play an important role in transmitting ZCL. In the present study, we report Leishmania infection in calomyscid rodents for the first time in mountainous residential areas of Shiraz, the capital of Fars Province, in southern Iran. Rodents were trapped in urban mountainous areas. The skin, liver, and spleen of rodents were examined microscopically for Leishmania infection. In addition, DNA was extracted from the tissues and they were evaluated for Leishmania infection by targeting the kDNA and subsequent sequencing of the nuclear rDNA internal transcribed spacer two (ITS2) region. DNA of L. major was detected in the spleen and liver of calomyscid rodents. Molecular evolution based on DNA-sequencing of the ITS2 gene confirmed the taxonomic situation of the parasite as L. major. Our findings suggest the eco-epidemiological importance of calomyscid rodents in the foci of leishmaniasis in the mountainous residential area on the plateau of Iran. These rodents may play a role in the transmission of leishmaniasis in a residential area and could be considered a potential reservoir for CL.

Haematopinus suis(H. suis) is a common ectoparasite of pigs and is economically important worldwide. H. suis is responsible for anemia and poor feed conversion rate that lead to poor growth in pig husbandry. This study assessed the prevalence and risk factors of H. suis in pigs through a cross-sectional survey in Busogo sector of Musanze district. Fifty-five (55) pigs, representing 10% of 555 pigs from 20 farms, were examined physically for the presence of H. suis, and a total number of 559 H. suis were collected from them in Busogo sector of Musanze district. Data were analyzed using the Statistical Package for the Social Sciences (SPSS). Results showed that out of 55 pigs, a total number of 35 pigs (63.6%), were found infested with H. suis in Busogo sector of Musanze district. The infestation by H. suis was associated with the farming system, animal breeds, animal's category, sex, pig hygiene, and piggery hygiene. Results showed a high (P < 0.05) prevalence in pigs reared in the intensive system (91.4%), whereas large whites were the most affected breed (60%). The prevalence of H. suis varied significantly (P < 0.05) among sexes, and females were the most affected (60%). Results related to pig hygiene revealed that all farmers were practicing washing skin three times per week, whereas only 60.0% of them were removing the bedding in their piggery. The study concluded that H. suis is present and remains a problem in the study area. Therefore, the study recommends to create farmer's awareness on the disease in pigs and its impact through training. Researchers should continue further studies on H. suis prevention with appropriate pig husbandry and management practices and the efficacy of acaricides used.

Background: The emergence and rapid spread of antimicrobial drug-resistance microorganisms exacerbate the treatment of infectious diseases, underscoring the importance of finding new, safe, and effective drugs. In Ethiopia, the roots of Carduus leptacanthus have traditionally been employed to treat microbial infectious diseases The aim of this study was to evaluate the antibacterial activity of the root extract and its primary components against six bacterial strains (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumonia).

Methods: The extraction involved maceration of air-dried and powdered roots of C. leptacanthus with 80% methanol. The compound was isolated from the root extract using silica gel column chromatography and recrystallization in CHCl₃/MeOH (9 : 1) and was characterized using ESI-MS and 1D-NMR spectroscopy. Antibacterial activity of the extract was assessed using agar well diffusion and broth microdilution methods.

Results: Syringin, a phenylpropanoid, was isolated and characterized from the extract of C. leptacanthus. The extract showed the most substantial efficacy against S. epidermidis (MIC = 5.33 mg/ml and inhibition zone diameter of 24 mm at 200 mg/m). Syringin also elicited antibacterial activity against S. aureus (MIC = 13.33 mg/ml), S. epidermidis (MIC = 16 mg/ml), and S. agalactiae (MIC = 16 mg/ml). Despite being tested up to a maximum concentration of 16 mg/ml, syringin did not exhibit antibacterial activity against the Gram-negative bacteria (P. aeruginosa, E. coli, and K. pneumonia).

Conclusions: In conclusion, the findings suggest that syringin exhibits partial involvement in the root extract's antibacterial activity, thereby potentially supporting the traditional medicinal use of the plant.

Background: Malaria is the leading cause of morbidity and mortality in African countries. We aimed this study at evaluating the in vitro antiplasmodial, antioxidant, and cytotoxicity activity of Lophira lanceolata extracts.

Method: The aqueous and ethanol extracts were obtained by maceration. It tested in vitro the extracts against Plasmodium falciparum 3D7 and multiresistance Dd2. Macrophage cell lines (RAW 264.7 cells) and red blood cells were used for cytotoxicity tests. The antioxidant activity was assessed by 1,1-diphenyl-2-picrylhydrazine (DPPH), hydrogen peroxide (H₂O₂), nitric oxide (NO) reduction, and ferric reducing antioxidant power (FRAP) scavenging.

Results: The in vitro antiplasmodial results showed that the ethanol extract was the most active, with IC50 of 24.51 ± 4.77 µg/mL and 31.86 ± 3.10 µg/mL, respectively, on the resistant Dd2 and sensitive 3D7 strains unlike the aqueous which indicated moderate activity with an IC₅₀ of 51.36 ± 4.86 μg/mL and 56.36 ± 4.27 μg/mL, respectively, on the resistant Dd2 and sensitive (3D7) strains. However, the ethanol extract had the highest activity, with an IC₅₀ of 8.153 g/mL, 1915 g/mL, 30.81 g/mL, and 54.66 g/mL, respectively, for DPPH, H₂O₂, NO, and FRAP, while the aqueous extract had an IC₅₀ of 6.724, 2387681, 185.7, and 152.0 g/mL, respectively, for DPPH, H₂O₂, NO, and FRAP. The cytotoxicity test reveals that both extracts do not promote red blood cell haemolysis. They presented weak activity against RAW 264.7 cells and red blood cells.

Conclusion: According to these findings, the aqueous and ethanol extracts have antiplasmodial and antioxidant activity but with no cytotoxic effects on red blood cells or RAW cells. However, it will be important to investigate the in vivo antiplasmodial and antioxidant activity of these extracts.

Background: Food handlers should be screened periodically for intestinal parasitic infections, and they should be treated to reduce intestinal parasite transmission to consumers through contaminated foods and drinks. Therefore, this study aimed to assess the prevalence and associated risk factors of intestinal parasitic infection among food handlers in Woldia town, North-East Ethiopia.

Method: A community-basedcross-sectional study was conducted among food handlers in Woldia town, North-East Ethiopia. A structured questionnaire was used to collect sociodemographic characteristics and intestinal parasite-associated risk factors. Microscopic examination of a stool sample was performed using wet-mount and formol-ether concentration techniques. Data were analyzed using SPSS version 20.0 statistical software packages. Bivariate and multivariate analyses were performed to investigate the association between intestinal parasitic infections and associated risk factors. In all comparisons, P value <0.05 was considered as statistically significant.

Result: The overall prevalence of intestinal parasitic infection among food handlers in Woldia town was 14.3%. Six different intestinal parasites were detected. The majority of the parasites identified were helminthic infections 37/52 (71%). Ascaris lumbricoides was the most dominant parasite (7.7%), followed by E. histolytica/dispar (2.7%) and G. lamblia (1.4%). Multivariate logistic regression analysis showed that intestinal parasitic infection had a statistically significant association with food handlers' habits of hand washing without soap after latrine use (P < 0.01), swimming habit (P=0.03), and using a common knife (P < 0.01).

Conclusion: This study revealed a relatively high prevalence of intestinal parasites among food handlers in Woldia town. Strict and standard hygienic and sanitary practices should be implemented by food handlers. Moreover, food handlers should be screened for intestinal parasitic infection, and health education should be given periodically.

Acinetobacter baumannii (A. baumannii) is an opportunistic bacterium that has developed multidrug resistance (MDR) to most of today's antibiotics, posing a significant risk to human health. Considering the fact that developing novel drugs is a time-consuming and expensive procedure, this research focuses on utilizing computational resources for repurposing antibacterial agents for A. baumannii. We targeted shikimate kinase, an essential enzyme in A. baumannii, that plays a significant role in the metabolic process. The basis for generating new therapeutic compounds is to inhibit the shikimate kinase and thereby targeting the shikimate pathway. Herein, 1941 drug-like compounds were investigated in different in silico techniques for assessing drug-likeness properties, ADMET (absorption, distribution, metabolism, excretion, and toxicity) profiling, binding affinity, and conformation analysis utilizing Autodock-vina and SwissDock. CHEMBL1237, CHEMBL1237119, CHEMBL2018096, and CHEMBL39167178 were determined as potential drug candidates for suppressing shikimate kinase protein. Molecular Dynamics Simulation (MDS) results for root mean square deviation, root mean square fluctuation, hydrogen bond, and gyration radius confirm the drug candidates' molecular stability with the target protein. According to this study, CHEMBL1237 (Lisinopril) could be the most suitable candidate for A. baumannii. Our investigation suggests that the inhibitors of shikimate kinase could represent promising treatment options for A. baumannii. However, further in vitro and in vivo studies are necessary to validate the therapeutic potential of the suggested drug candidates.

Wolbachia, a Gram-negative intracellular bacterium, naturally infects many arthropods, including mosquito vectors responsible for the spread of arboviral diseases such as Zika, chikungunya, and dengue fever. Certain Wolbachia strains are involved in inhibiting arbovirus replication in mosquitoes, and this phenomenon is currently being studied to combat disease vectors. A study was conducted in four states in north-eastern India to investigate the presence of natural Wolbachia infection in wild-caught Aedes albopictus and Aedes aegypti mosquitoes, the established vectors of dengue. The detection of a Wolbachia infection was confirmed by nested PCR and sequencing in the two mosquito species Ae. aegypti and Ae. albopictus. Positivity rates observed in Ae. aegypti and Ae. albopictus pools were 38% (44 of 115) and 85% (41 of 48), respectively, and the difference was significant (chi-square = 28.3174, p = 0.00000010). Sequencing revealed that all detected Wolbachia strains belonged to supergroup B. Although Wolbachia infection in Ae. aegypti has been previously reported from India, no such reports are available from north-eastern India. Data on naturally occurring Wolbachia strains are essential for selecting the optimal strain for the development of Wolbachia-based control measures. This information will be helpful for the future application of Wolbachia-based vector control measures in this part of the country.

Background: Nepal faced a major dengue outbreak in 2022. The majority of hospitals and laboratories had limited resources for dengue confirmation and had to rely on rapid dengue diagnostic tests. The purpose of the study is to find the predictive hematological and biochemical parameters in each serological phase of dengue infection (NS1 and IgM) that may assist in dengue diagnosis, severity assessment, and patient management via the use of rapid serological tests.

Method: A laboratory-based cross-sectional study was conducted among dengue patients. Rapid antigen (NS1) and serological test (IgM/IgG) was performed to diagnose positive dengue cases. Furthermore, hematological and biochemical investigations were carried out and compared between NS1 and/or IgM-positive participants. A logistic regression analysis was used to identify the validity of the hematological and biochemical characteristics for dengue diagnosis as well as patient management. Receiver-operating characteristic (ROC) curve analysis was used to define the best cut-off, sensitivity, and specificity.

Result: Multiple logistic regression showed thrombocytopenia (OR_A = 1.000; p = 0.006), leukopenia (OR_A = 0.999; p < 0.001), glucose level (OR_A = 1.028; p = 0.029), aspartate aminotransferase (OR_A = 1.131; p = 0.001), and monocytosis (OR_A = 2.332; p = 0.020) as significant parameters in the NS1-only positive group. Similarly, thrombocytopenia (OR_A = 1.000; p = 0.001), glucose level (OR_A = 1.037; p = 0.004), and aspartate aminotransferase (OR_A = 1.141; p < 0.001) were significant in IgM-only positive patients. Moreover, thrombocytopenia (OR_A = 1.000; p < 0.001), leukopenia (OR_A = 0.999; p < 0.001), glucose (OR_A = 1.031; p = 0.017), aspartate aminotransferase (OR_A = 1.136; p < 0.001), and lymphopenia (OR_A = 0.520; p = 0.067) were independent predictors in both NS1 + IgM positive groups. Platelets consistently demonstrated a higher area under the curve with increased sensitivity and specificity throughout all models, while aspartate aminotransferase (AUC = 0.811) and glucose (AUC = 0.712) demonstrated better results when single IgM positivity was observed. The total leukocyte count performed better when both NS1 + IgM were positive (AUC = 0.814).

Conclusion: Hence, thrombocytopenia, elevated AST, high glucose level, leukopenia with monocytosis, and leukopenia with lymphopenia may predict dengue diagnosis and its severity during an active infection. Therefore, these laboratory parameters can be used to complement less sensitive rapid tests, improve dengue diagnosis, and help with proper patient management.

The emergence of multidrug bacterial resistance poses a great public health problem and requires a constant search for new antibacterial agents. However, Niger's flora possesses several medicinal plants used in traditional medicine to cure infectious diseases and can be used as sources of bioactive ingredients. This current study was designed to evaluate the antibacterial activity of eight plants used in the traditional pharmacopeia of Niger. The extracts were prepared by maceration using ethanol, methanol, and distilled water. The obtained extracts were screened against Salmonella spp., Shigella spp., and Escherichia coli using the microdilution method coupled with a resazurin-based assay. Phytochemical screening was performed using colorimetry, while the quantification of total polyphenols, total flavonoids, and total tannins was determined by spectrophotometry. Out of the eight plants obtained, five named Cassia italica, Limeum pterocarpum, Phyllanthus pentandrus, Strychnos innocua, and Ximenia americanum exhibited antibacterial activity with MICs ranging from 500 μg/mL to 2000 μg/mL. Phytochemical screening showed the presence of alkaloids, saponosides, tannins, flavonoids, terpenes/sterols, quinones, and polyphenols. The ethanolic and methanolic extracts of X. americana contained important quantities of total polyphenols, with 43.59 ± 0.15 and 41.97 ± 0.02 mg EAG/100 mg of extract, respectively. These extracts showed the highest contents of total tannins at 46.49 g/L and 45.52 g/L, respectively. For total flavonoids, the highest content was obtained with the methanolic extract of P. pentandrus, with 3.12 ± 0.01 mg QE/100 mg of extract. These findings justify the uses of these plants in traditional medicine for the treatment of infectious diseases such as diarrhea and can be used as starting points for the development of phytodrugs against infectious diarrhea.

Background: Toxocariasis is an important zoonotic infection, especially in tropical areas. One of the significant challenges in the serodiagnosis of human toxocariasis is the cross-reaction of Toxocara antigens with other parasites due to their relatively similar glycan structures. Removing the glycan structure from Toxocara excretory-secretory (TES) antigens may increase the efficacy of these antigens in the diagnosis of toxocariasis. The current study aimed to assess the efficacy of deglycosylated Toxocara cati excretory-secretory (dTES) antigens for the serodiagnosis of human toxocariasis.

Methods: Toxocara ES antigens were prepared from T. cati second-stage larvae and deglycosylated using sodium hydroxide (NaOH). The TES antigens, along with the dTES antigens, were used in an ELISA as well as a western blotting system for the detection of anti-Toxocara antibodies. Sera samples collected from 30 confirmed cases of toxocariasis, 30 patients with other diseases, and 30 healthy subjects were evaluated by both systems.

Results: The sensitivity of TES and dTES ELISA for the diagnosis of human toxocariasis was 96.67% (95% CI = 82.78-99.92) and 93.33% (95% CI = 77.93-99.18), respectively, while the specificity of dTES (88.33%; 95% CI = 77.43-95.18) increased significantly compared to the TES (80.00%; 95% CI = 67.67-89.22). The sensitivity of both antigens was 100% (95% CI = 88.43-100) by the western blotting system. Moreover, the specificity of TES and dTES antigens was 95% (95% CI = 86.08-98.96) and 98.33% (95% CI = 91.06-99.96), respectively, when using the western blotting system.

Conclusion: Results of the current study indicate that the chemical removal of the glycan epitopes of T. cati ES antigens significantly reduces cross-reactivity rates with other parasitic infections. Considering the findings of the present study, the dTES antigens seem to be suitable antigens for the serodiagnosis of human toxocariasis.