Tropical Medicine

Current status and future prospects of bacilli-based vector control Joleen Savianne Almeida, Ajeet Kumar Mohanty, Savita Kerkar, Sugeerappa Laxmanappa Hoti, Ashwani Kumar Asian Pacific Journal of Tropical Medicine 2020 13(12):525-534 Mosquito-borne diseases such as malaria, filariasis, dengue, chikungunya, Japanese encephalitis, yellow fever and Zika contribute significantly to health problems of developing as well as developed nations. Vector control is central to control of vector borne diseases. In the last four-five decades, biological control methods have been inducted in the integrated vector management strategy, advocated nationally as well as globally by the World Health Organization. Currently, biological control of vectors is globally acknowledged as the best available strategy in the wake of growing concerns about vector resistance as well as adverse effects of insecticides on the environment and non-target fauna co-inhabiting the same ecological niches as vectors. In India and elsewhere, efforts are ongoing to screen newer isolates to bring forth new biolarvicidal products of public health importance. In this review, by carrying out extensive literature survey, we discuss advances thus far and the prospects of bacilli-based control of vectors and vector borne diseases.

Patterns of hepatitis B virus exposure and associated predictors in Vietnam: A crosssectional study Minh C Duong, Phuc V.D. Le, Oanh N.K. Pham, Hien D.T. Pham, Toan B Nguyen, Hai T Phan Asian Pacific Journal of Tropical Medicine 2020 13(12):535-541 Objective: To examine the magnitude of isolated anti-HBc and other HBV serological patterns and associated predictors among adults seeking general health check-up at a large health center in Vietnam. Methods: All 564 outpatients seeking general health checkup between January 2016 and December 2016 were asked to undertake HBV surface antigen, surface antibody, IgG and IgM core antibody (anti-HBc total), platelet counts, and liver function testing. An administered questionnaire was used to collect information regarding demography, in-house sources of infection, lifestyle, health condition and treatment, and HBV vaccination. Results: Male gender (P=0.043), age (P=0.000), living in urban areas (P=0.040), HBV vaccination status (P=0.033), and ALT (P=0.040) were associated with isolated anti-HBc. HBV infection was associated with HBV vaccination status (P=0.001), ALT levels (P=0.010), AST levels (P=0.020), and platelet counts (P=0.007). Past/resolved HBV infection was associated with AST levels (P=0.005), ALT levels (P=0.014), and age (P=0.000). Conclusions: Isolated anti-HBc is quite prevalent. Predictors of isolated anti-HBc include male gender, living in rural areas, and HBV non-vaccination. The prevalence of isolated anti-HBc also increases with age. To timely detect occult HBV infection and prevent transmission, anti-HBc testing should be included in the health check-up for high risk individuals and screening program where HBV nucleic acid test is not available. To prevent transmission, clinicians need to pay more attention on those who are at risk of having isolated anti-HBc and closely follow-up patients with isolated anti-HBc and educate them about the prevention of HBV infection.

Morphological and molecular characterization of Acanthamoeba isolated from contact lens paraphernalia in Malaysia: Highlighting the pathogenic potential of T4 genotype Rosnani Hanim Mohd Hussain, Nur Syahirah Mohamad Isa, Khairul Ameera Kamaruddin, Mohamed Kamel Abdul Ghani, Naveed Ahmed Khan, Ruqaiyyah Siddiqui, Tengku Shahrul Anuar Asian Pacific Journal of Tropical Medicine 2020 13(12):542-549 Objective: To determine the morphological and molecular characterization of Acanthamoeba isolates from contact lens paraphernalia in Malaysia and to investigate their pathogenic potential based on the physiological tolerance. Methods: One hundred and eighty contact lens wearers donated their contact lens, lens storage cases and lens solutions between 2018 and 2019. The samples were inoculated onto 1.5% non-nutrient agar plates for 14 d. Polymerase chain reaction (PCR) was performed and the amplified PCR products were sequenced and compared with the published sequences in GenBank. The pathogenic potential of positive isolates was further tested using temperature-tolerance and osmo-tolerance assays. Acanthamoeba species were categorized into three distinct morphological groups established by Pussard and Pons. Results: Acanthamoeba was successfully isolated from 14 (7.8%) culture-positive samples in which 11 belong to morphological group II and 3 belong to morphological group III, respectively. The sequencing of 18S ribosomal RNA gene led to the identification of the T4 genotype in all the isolated strains. In vitro assays revealed that 9 (64.3%) Acanthamoeba isolates were able to grow at 42 °C and 1 M mannitol and were thus considered to be highly pathogenic. Conclusions: To the best of our knowledge, this is the first report identifying the Acanthamoeba genotype and their pathogenic potential among contact lens wearers in Malaysia. The potentially pathogenic T4 genotype isolated in this study is the most predominant genotype responsible for human ocular infection worldwide. Hence, increasing attention should be aimed at the prevention of contamination by Acanthamoeba and the disinfection of contact lens paraphernalia.

Multiplex real-time PCR revealed very high prevalence of soil-transmitted helminth infections among aborigines in Peninsular Malaysia Nurulhasanah Othman, Noorizan Miswan, Weng-kin Wong, Boon-huat Lim, Rahmah Noordin Asian Pacific Journal of Tropical Medicine 2020 13(12):550-556 Objective: To determine the true prevalence of soil-transmitted helminth infections in the Malaysian aborigines using real-time PCR. Methods: A total of 122 aborigines from seven tribes were recruited from settlements and nearby hospitals which served the communities, located in four states in Peninsular Malaysia. The stool samples were examined for the presence of soil-transmitted helminth using real-time PCR and microscopy. The latter included the direct wet mount and formalin-ether concentration technique (FECT). The infection load in FECT-positive samples was determined by the Kato-Katz method. Rotorgene real-time analyzer detected five helminth species using two sets of assays. Results: The real-time PCR detected soil-transmitted helminth in 98.4% samples (n=122), which were 1.56 times higher than by microscopy. Ascaris lumbricoides and Trichuris trichiura were detected in more than 90% of the samples, while hookworm was detected in 46.7% (Necator americanus) and 13.9% (Ancylostoma sp.) of the samples. Comparison with previous reports on the Malaysian aborigines showed that the real-time PCR markedly improved the detection of Ascaris lumbricoides, hookworm and Strongyloides stercoralis. The real-time PCR detected poly-helminths in 92.6% of the samples compared to 28.7% by microscopy. In addition, 27 samples (22.1%) showed amplification of Strongyloides stercoralis DNA. Conclusions: The real-time PCR showed very high prevalence rates of soil-transmitted helminth infections in the aborigines and is the recommended method for epidemiological investigation of soil-transmitted helminth infections in this population.

Fermentation of mulberry leaves with Cordyceps militaris enhanced anti-adipogenesis activity in 3T3-L1 cells through down-regulation of PPAR-γ pathway signaling Lu Guo, Jum Soon Kang, Young Hoon Park, Beong Il Je, Dae Youn Hwang, Woo Hong Joo, Young Whan Choi Asian Pacific Journal of Tropical Medicine 2020 13(12):557-565 Objective: To establish an efficacious and efficient fermentation method of enhancing the anti-adipogenesis effect of mulberry (Morus alba) leaves using Cordyceps militais. Methods: Dried mulberry leaves, dried mulberry leaves with 50% raw silkworm pupa and raw silkworm pupa were fermented with Cordyceps militais for 4 weeks at 25 °C, after which the dried mulberry leaves and fermented product were extracted with 70% ethanol and subjected to high performance liquid chromatography (HPLC). The contents of cordycepin, pelargonidin, chlorogenic acid, iso-quercetin and caffeic acid were determined. We then used the 3T3-L1 cells to investigate whether extracts of fermentation enhanced anti-adipogenesis activity in vitro. Results: HPLC showed that fermentation changed the contents of cordycepin, pelargonidin, chlorogenic acid, iso-quercetin and caffeic acid. Furthermore, fermented dried mulberry leaves with 50% raw silkworm pupa had a better efficacy of anti-adipogenesis than dried mulberry leaves, fermented dried mulberry leaves and fermented silkworm pupa and inhibited triglycerides accumulation and glucose consumption. Additionally, fermented dried mulberry leaves with 50% raw silkworm pupa inhibited PPAR-γ signaling. Conclusions: Fermentation with Cordyceps militaris enhanced anti-adipogenesis efficacy of mulberry leaves.

In vitro efficacy of new synthetic benzimidazole-related compounds against Schistosoma mansoni adult worms Amira Taman, Samia El-Bardicy, Menerva Tadros, Magda Ayoub, Basem Mansour, Fouad El-Shehabi, Samar N El-Beshbishi Asian Pacific Journal of Tropical Medicine 2020 13(12):566-572 Objective: To evaluate the in vitro antischistosomal activity of two new synthetic benzimidazole-related compounds: NBTP-OH and NBTP-F. Methods: Schistosoma adult worms were recovered from mice infected with Schistosoma mansoni cercaria, washed and then incubated in the culture media with different concentrations of compounds NBTP-OH and NBTP-F up to 72 h. Scanning electron microscopy was conducted to report morphological changes. Results: Incubation of adult Schistosoma mansoni with 10 μg/mL of NBTP-OH for 48 h killed 81.25% of worms. The calculated LC50 and LC90 72 h post-incubation were 6.8 μg/mL and 9.8 μg/ mL, respectively. Exposure of worms to 10 μg/mL of NBTP-F killed 89.5% of worms after 48 h, mostly males (83.3%), the LC50 and LC90 after 72 h of incubation were 4.8 μg/mL and 6.9 μg/mL, respectively. Worms incubated for 72 h with these compounds revealed swelling and deformity of oral sucker, disorganization and erosion of the tegument when examined with scanning electron microscopy. Conclusions: NBTP-OH and NBTP-F possess in vitro antischistosomal activities; however, in vivo studies should be conducted to examine their antischistosomal effects.

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Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com,

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