Tropical biomedicine最新文献

This study explored the transcriptome differences in Fasciola hepatica at different developmental stages and identified functional genes related to growth and development during juvenile stages. DNBSEQ eukaryotic strand-specific transcriptome resequencing technology was used to sequence the transcriptomes of Fasciola hepatica eggs, juveniles, and adults. Additionally, the genes that were highly expressed during the juvenile stage were validated using qRT-PCR. The Q20 values of all three phases of sequencing were above 98%, and the Q30 values were above 94%. The differentially expressed genes (DEGs) in pairwise comparisons were analyzed by GO functional classification and the KEGG pathway database. Many immune-, growth-, and development-related pathways were found, which might be related to cell proliferation, development, and host immune evasion by Fasciola hepatica. In addition, five DEGs with high expression levels during the juvenile stage were identified: Cathepsin B, Glutathione S-transferase mu, heat shock protein 67B2, Kunitz-CH, and Legumain. Validation analyses revealed that these genes play key roles in maintaining normal growth, development, and immunological processes in liver Fasciola hepatica. RNA-seq was used to analyze the biological characteristics of the DEGs at different developmental stages concerning GO functional classification and KEGG metabolic pathways. Five DEGs with high expression during the juvenile stage were identified. These genes are related to the growth, development, and immune function of Fasciola hepatica, which provides a theoretical basis for subsequent research on the proteomics of Fasciola hepatica and the screening of candidate genes for early diagnosis.

Blastocystis a single-celled eukaryotic protist, is known to inhabit the intestines of various hosts, including humans, and has been implicated in a wide spectrum of symptoms, ranging from gastrointestinal issues to skin disorders, thereby establishing its status as an emerging infectious agent. In this study, the prevalence of Blastocystis infection was investigated in insects, including cockroaches, houseflies, and crickets, as well as sea turtles. Additionally, the genotypic characteristics of the isolated Blastocystis strains were examined, and the evolutionary relationships between Blastocystis species found in sea turtles, and animals/humans were determined. Microscopic techniques and molecular methods were utilized in this study. The results showed that four out of 90 insects (4.44%) and one out of 13 sea turtles (7.7%) were infected by Blastocystis. Furthermore, detailed observations revealed the presence of characteristic morphological features, such as vacuolar forms in the cockroach, cricket and sea turtle samples and binary fission from cockroach samples, indicative of Blastocystis' mode of reproduction. While the ST8 of Blastocystis in sea turtles were successfully identified, no subtyping was achieved for the infected insects. This study not only establishes the occurrence of Blastocystis infection in sea turtles but also uncovers its ability to infect insects, suggesting a potential reservoir role for these organisms. Overall, this research emphasizes the significance of comprehending the prevalence, genotypic diversity, and evolutionary relationships of Blastocystis across various hosts. Such insights are instrumental in developing effective control measures and public health interventions to mitigate the associated symptoms and prevent future outbreaks.

Rice is often associated with Bacillus cereus (B. cereus) food poisoning. This review aims to explore the food poisoning activity, antimicrobial resistance, and control measures of B. cereus in rice from 1974 to October 2023. We searched for eligible studies from the PubMed database based on explicit criteria following the PRISMA checklist. A total of 117 articles were collected, and the final analysis included 29 studies. Quality appraisal was performed using AMSTAR 2, SANRA 2, and Critical Appraisal Tool standards. B. cereus can grow and multiply in food to cause emetic vomiting or diarrheal syndrome. The primary etiology of B. cereus contamination is improper food handling and storage temperature during the cooking, cooling, and reheating stages of rice. The alarming rise of antimicrobial resistance in B. cereus to beta-lactam antibiotics necessitates alternatives from natural antimicrobial preservatives such as carvacrol, chitosan, or trans-cinnamaldehyde to prevent microbial infestation and toxin production. Implementing food safety strategies tailored to specific food settings, such as restaurants and factorymanufactured ready-to-eat rice, is critical for preventing food contamination by B. cereus. Given the heat-resistant spores and intoxication properties of B. cereus, it is important to develop effective interventions and hygienic protocols from farm to fork.

Liver fluke infection, particularly Opisthorchis viverrini, poses a significant public health risk in Thailand, where it is closely associated with cholangiocarcinoma and contributes to substantial mortality in the northeastern region. Diagnosis of this condition employs various parasitological approaches. This research aims to compare the diagnostic accuracy of three parasitological techniques: the Kato Katz technique (KKT), the formalin-ethyl acetate concentration technique (FECT), and the Fully Automatic Feces Analyzer (FAFA) for O. viverrini identification. A total of 455 fecal specimens were collected from rural areas across five provinces in northeastern Thailand. The specimens were processed according to each method and examined through microscopy for KKT and FECT, and by utilizing an artificial intelligence-based machine for FAFA. Data analysis was conducted to assess parasitic infection rates and observe diagnostic accuracy. The results revealed a parasitic infection rate of 19.34%, with the majority of infections attributed to O. viverrini (18.02%), followed by Strongyloides stercoralis (0.88%). FECT exhibited the highest positive detection of O. viverrini eggs (16.48%), followed by FAFA (10.55%), and KKT (8.57%), respectively. Statistical analysis indicated sensitivity and specificity values for O. viverrini detection by KKT (100% and 89.21%), FECT (98.67% and 97.63%), and FAFA (97.92% and 91.15%). The positive predictive value, negative predictive value, and kappa were reported for FECT (89.16%, 99.73%, 0.92), FAFA (56.63%, 99.73%, 0.67), and KKT (45.78%, 100%, 0.58). Additionally, the preparation time for KKT, FECT, and FAFA was 30, 15, and 10 min, respectively. In conclusion, this study highlights FECT, KKT, and FAFA as comparably sensitive in diagnosing O. viverrini. The FAFA machine emerges as a potentially valuable tool for detecting O. viverrini and other parasitic infections, showcasing promise for clinical use. The findings provide valuable insights into the diagnostic landscape and underscore the potential of FAFA in enhancing efficiency and accuracy in parasitological assessments.

Blastocystis is a ubiquitous waterborne parasite that has been implicated in some disease conditions including colorectal cancer and irritable bowel syndrome, and its surface coat characteristics have been associated with its pathogenicity. Although the morphology of Blastocystis isolates from human and animal sources have been studied, there is a paucity of data on the surface ultrastructure of Blastocystis isolated from water sources. Therefore, this study aimed to determine the occurrence and the ultrastructural surface of Blastocystis isolates from several water sources in Kedah and Penang, Malaysia. A total of 12 water samples were collected, namely, Pinang River and USM Harapan Lake all in Penang, whereas Lata Bayu Waterfall in Baling and UniSHAMS Lake, Kuala Ketil in Kedah. These were examined for Blastocystis by centrifugation and in vitro cultivation. Scanning electron microscopy (SEM) and light microscopy were employed to study the morphological characteristics and the surface ultrastructure of the parasite. Polymerase chain reaction (PCR) was carried out to obtain the subtypes (ST) of the positive Blastocystis isolates. The result revealed 25.0% (3/12) contamination with Blastocystis in which ST1, ST2, and an unknown ST (with a high similarity to ST1) were detected in water samples from the upstream, downstream, and midstream, respectively of Pinang River. Our study also revealed similarities in the sizes of the isolates from different river points, which were notably more diminutive compared to the sizes of the parasites observed in existing data from human and animal isolates. The surface characteristics showed a collection of single and dividing cells with smooth, folded surfaces enclosed in a film-like layer. Additionally, there were roundish, irregularly shaped cells with rough surfaces, and a woolly appearance. This study has added to our knowledge of the surface ultrastructure of Blastocystis and its possible contribution to the pathogenicity of the parasite.

Vector-borne diseases have been a growing health concern in recent decades due to the global warming, globalization, and increased international travel. With the typical Mediterranean climate and geographical features, Cyprus provides favorable conditions for the growth and survival of arthropod species. For the purpose of this review article, the terms "Cyprus", "vectors" and "vectorborne diseases" were searched in the National Library of Medicine ('PubMed') and the Google Scholar databases. Published articles in the literature have documented mosquito (including Anopheles, Aedes, Culex, and Culiseta), sandfly (Phlebotomus, Sergentomyia), flea (including Ctenocephalides, Xenopsylla, Leptopsylla), and tick (including Rhipicephalus, Ixodes, Hyalomma, Haemaphysalis) species in the island. The presence of these arthropods poses a risk to public health as they can transmit a variety of diseases to both humans and animals. Research studies in Cyprus have identified infectious agents such as West Nile virus, Leishmania spp., sandfly viruses, Rickettsia spp., Coxiella burnetii, and Bartonella spp. in the local arthropods. More importantly, West Nile virus infection and imported malaria cases (mosquitoborne diseases); leishmaniasis and sandfly fever (sandfly-borne diseases); rickettsiosis, tularemia, Q fever, anaplasmosis, tick-borne relapsing fever, and Lyme disease (tick-borne diseases); and flea-borne rickettsiosis were reported in Cyprus. Taken together with the presence of arthropod vectors, published evidence in the literature suggests that Cyprus is an important region for VBDs. In addition to its climatic and geographical conditions, international travels particularly from endemic countries pose a risk for the circulation of VBDs on the island. Therefore, vector control programs should be continuously implemented, and public awareness must be raised in the region. This review, which to the best of our knowledge is the first comprehensive report on VBDs from Cyprus, will provide insight into future islandwide studies and also will be an important contribution to the elimination of VBDs in the region.

Plasmodium knowlesi, primarily a zoonotic malaria species is the most common malaria pathogen in the Southeast Asia especially in Malaysian Borneo, Malaysia. Due to morphological resemblance of P. knowlesi to other human Plasmodium, the sensitivity for microscopic detection of P. knowlesi, which is the gold standard, is compromised. Thus, efforts have been made in finding alternatives for the disease diagnosis. This study described the potential use of anti-PkTRAMP polyclonal antibodies in sandwich ELISA for P. knowlesi detection. Anti-PkTRAMP polyclonal antibodies raised from mice and rabbit were first evaluated for their binding capability towards native proteins in P. knowlesi lysates using Western blot. These mice and rabbit polyclonal antibodies were then used in the sandwich ELISA as capture and detection antibodies, respectively. P. knowlesi A1H1 culture was utilised to determine the limit of detection (LOD) of this assay. Its clinical performance was determined by testing with archived human malaria and uninfected samples. Western blot analysis affirmed the polyclonal antibodies reactivity to P. knowlesi. The LOD obtained from three replicated assays was at 0.015% parasitaemia. The assay has 76% sensitivity and 75% specificity for P. knowlesi. Its positive and negative predictive values were 76% and 75%, respectively. No cross reactivity with P. falciparum and healthy samples was observed, except for P. vivax where 10 out of 12 samples were detected. In conclusion, anti-PkTRAMP polyclonal antibodies can be useful in detecting P. knowlesi. Regardless, the full potential of anti-PkTRAMP antibodies for diagnostic purposes need to be explored further.

Toxoplasmosis is an infectious disease caused by the intracellular protozoan parasite, Toxoplasma gondii. While the infection is typically asymptomatic in healthy individuals, it can progress to cerebral toxoplasmosis, especially in those with human immunodeficiency virus (HIV) or weakened immune systems. In this communication, we present a case of a newly diagnosed HIV infection patient who presented with neurological symptoms. The patient was later diagnosed with probable cerebral toxoplasmosis. The case depicts the severe consequences of toxoplasmosis in immunocompromised patients, highlighting the urgent need to identify those at high risk of contracting the disease and the importance of prophylactic treatment. This requires the necessity for early HIV diagnosis and close monitoring of HIV-positive patients.

The study has generated visible aerosols with the diameter of 11 to 35 µm from the kenaf cellulose nanofiber (KCNF) impregnated with the temephos (KCNF+T) in water suspension. The study aimed to determine whether the KCNF+T aerosols are capable to elicit neurotoxicity in the adult mosquitoes via the respiratory exposure route by observing their behavioural response and measuring its body acetylcholine esterase (AChE) activity. Adult Aedes aegypti mosquitoes were assigned to one negative control group and three treatment groups namely, distilled water (vehicle control), KCNF and KCNF+T. The study adopted the MS1911 whereby the aerosols generated are released into the insecticide bioassay glass chamber (IBGC) separately to achieve four different aerosols concentrations of 6.4 ml/m³, 12.8 ml/m³, 19.2 ml/m³, and 25.6 ml/m³. Then the 20 sugar-fed mosquitoes were released free-flying into each IBGC to observe its behavioural response (knockdown) at 30, 60, 120, 180, 240, 300 minutes intervals and 24^th hour mortality. Results showed that only mosquitoes exposed to KCNF+T aerosols exhibited persistent knockdown. There was significant difference (p< 0.05) between observation intervals with the cumulative knockdown of 84.8%, 92.8%, 99.0%, 100.0%, 100.0%, 100.0% compared with the KCNF aerosols. Further, it was distinctive that only KCNF+T is capable to cause the female mosquitoes moribund/mortality at the 24th hour with 90% at the lowest aerosol concentration of 6.4 ml/m³. The neuroenzyme assay on the mosquito that died from the KCNF+T exposure verified to have reduced AChE enzyme activity. The behavioural response and reduction of the AChE activity strongly suggests the temephos from the KCNF+T aerosols has been released into the mosquito body causing the neurotoxicity but KCNF alone is not neurotoxic.

Dengue fever is one of the most common diagnoses in patients presenting with acute febrile illness in tropical countries. Borrelia, on the other hand, is the cause of vector-borne infections of relapsing fever and Lyme disease. While co-infections of dengue with chikungunya, Zika, malaria, influenza and typhoid have been reported, clinical cases of Borrelia infections have never been reported in Malaysia. Based on available evidence, this is the first case series to report dengue fever and Borrelia spp. co-infection. All three patients in this report were admitted to medical wards on day 3 to day 8 of illness for dengue fever as evidenced by a positive dengue NS1 antigen test. The clinical manifestations were typical of dengue fever, with all patients having high grade fever, myalgia, and arthralgia. All patients also had thrombocytopenia. Features of severe dengue, such as shock, hemorrhage and impaired consciousness were absent. Borrelia DNA were detected in the blood samples of the patients. However, all the patients denied having skin lesions and a history of insect bites. All the patients were given intravenous fluid therapy and were discharged after 3 to 5 days of hospitalization.