Corona virus (COVID-19) infection has been growing as a biggest threat to human society. World Health Organization (WHO) has already declared it as a pandemic for the whole world, with nearly six million positive cases. Highly contagious nature of the virus has challenged the medical facilities of all the developed and developing country health system. Early identification of the infection is very important to provide medical facilities and cease the chain of infection to new persons. The symptoms such as fever, dry cough, breathing issues generally show in patients not before 5-7 days. However, the patients feel the loss of smell or taste (anosmia) as early as second day onwards due to the presence of virus in nose and throat. Low-cost techniques such as SniffIn-sticks ® Smell Test and UPSIT etc. can be used to test anosmia along with medically approved olfactory test leading to identification of COVID-19 infections. With leading researchers findings anosmia test will be effective in breaking the chain infection of COVID-19 virus. In the exit ports, anosmia test kits may be added to thermal testing to identify the infected patients with low symptoms. Additionally, home test kits may be developed at low cost and supplied for large scale testing of the infection.
MeSH terms: Female; Humans; Male; Health Care Costs*
Simulium (Simulium) contractum Takaoka from Sulawesi, Indonesia was known only as the pupa. Its female, male and mature larva are described for the first time. The tentative assignment of this species in the Simulium dumogaense species-group is confirmed by the adult characters including the female and male genitalia. The female and male of this species are similar to those of Simulium (Simulium) tumpaense Takaoka and Roberts but are distinguished by the yellowish femora.
Haemonchus spp. or barber's pole worms are one of the most highly pathogenic nematodes of ruminants causing economic losses in livestock worldwide. The current study was a first attempt to identify Haemonchus spp. from goats in Thailand and Lao PDR. Utilizing the inexpensive tools of the discriminant function (DF) combined with synlophe patterns is fundamental for understanding their epidemiological aspects. In total, 255 randomly chosen adult male Haemonchus worms from goats in various areas in each country were identified individually. For both these countries, about 94% based on the DF values, and 99%, 98%, and 97% based on synlophe patterns in the region of the esophageal intestinal junction (EI), 4 mm from the anterior end, and at both these positions, respectively, were identified as H. contortus. Other identified specimens defined as H. placei and hybrids as well as unclassified species based on synlophe patterns were proved using polymerase chain reaction (PCR); this also included some randomly chosen H. contortus by DF and synlophe patterns. All those specimens were confirmed as H. contortus being strongly supported by some genetic evidences and UPGMA analysis. Thus, it was assumed that all specimens in the current study were H. contortus. The morphological differences of this predominant species (H. contortus) in goats between the two countries were: body length, gubernaculum length, and left spicule barb length, while almost all characters of male worms individually measured appeared to overlap, mostly in H. contortus and H. placei, which may lead to misclassification. Therefore, using the DF along with synlophe patterns can assist in increasing the accuracy of Haemonchus spp. identification from goats in some areas where funding is limited, particularly in Lao PDR. The present results revealed that synlophe patterns in the EI region seemed to be promising for the identification of Haemonchus spp., while molecular techniques are also required to address ambiguous identification with some specimens.
Japanese encephalitis virus (JEV), a member of the family Flaviviridae, causes severe neurological disorders in humans. JEV infections represent one of the most widely spread mosquito-borne diseases, and therefore, it has been considered as an endemic disease. An effective antiviral drug is still unavailable to treat JEV, and current drugs only provide supportive treatment to alleviate the symptoms and stabilize patients' conditions. This study was designed to evaluate the antiviral activity of the sulphated polysaccharides "Carrageenan," a linear sulphated polysaccharide that is extracted from red edible seaweeds against JEV replication in vitro. Viral inactivation, attachment, and post-infection assays were used to determine the mode of inhibition of Carrageenan. Virus titters after each application were evaluated by plaque formation assay. MTT assay was used to determine the 50% cytotoxic concentration (CC50), and ELISA-like cell-based assay and immunostaining and immunostaining techniques were used to evaluate the 50% effective concentration (EC50). This study showed that Carrageenan inhibited JEV at an EC50 of 15 µg/mL in a dose-dependent manner with CC50 more than 200 µg/mL in healthy human liver cells (WRL68). The mode of inhibition assay showed that the antiviral effects of Carrageenan are mainly due to their ability to inhibit the early stages of virus infection such as the viral attachment and the cellular entry stages. Our investigation showed that Carrageenan could be considered as a potent antiviral agent to JEV infection. Further experimental and clinical studies are needed to investigate the potential applications of Carrageenan for clinical intervention against JEV infection.
Chikungunya virus infection had not been reported by the National Secretary of Health of the State of Baja California Sur, Mexico before 2015, and until now, no information of the disease has been published. Thus, the objective of this study was to assess the tendency that the disease has shown since its introduction. The total number of cases in the state was analyzed, and the incidence rate of infection was evaluated in the general population, age groups, and gender. From 2015-2019, the year with the highest number of reported cases was 2016 with 210 cases, but no cases were reported from 2018-2019. The gender with the highest number of cases was female. The most affected age group was adults 45-64 years of age.
Helminth infections (HIs) are an important public health problem in tropical countries, and the associated problems have been neglected in rural areas of Thailand. Therefore, this study reports the prevalence and intensity of HIs among inhabitants of the Khon Sawan district, Chaiyaphum province, and Kaeng Samnam Nang district, Nakhon Ratchasima province, which are located near the Chi River and Lahanna water reservoir, northeastern Thailand. A cross-sectional descriptive study was conducted between July 31, 2018, and June 30, 2019, among rural villagers from 40 rural villages in 4 subdistricts. The participants were selected from the village enrolment list after proportional allocation of the total sample size. Faecal samples from 691 inhabitants were prepared using solvent-free faecal parasite concentrator, and helminths were then detected using a light microscope. Statistical analysis included the Chi-square test with Yates correction, and multivariable logistic regression was performed. A P-value of <0.05 was considered statistically significant. The prevalence of HIs was 2.03%. The most prevalent helminths were Opisthorchis viverrini (1.31%), followed by Strongyloides stercoralis (0.44%), Ascaris lumbricoides (0.29%), hookworm (0.15%), Teania spp. (0.15%) and one minute intestinal fluke (0.15%). Coinfections were identified in 2 cases for S. stercoralis and hookworm and 1 case for O. viverrini and S. stercoralis infection. All infected participants had a light intensity of HI. There was no significant difference between general characteristics for all HIs. The prevalence of HIs was not significantly associated with general characteristics. This study indicates that the infections result mainly from foodborne helminths and skin-penetrating nematodes. Therefore, interventions should concentrate on the personal hygiene of the population and improving sanitation to reduce HIs in this area.
The study was aimed to investigate the expression of cytosolic and thiolated proteins of Musca domestica larvae under oxidative stress. Proteins from acute treatment of hydrogen peroxide (LC50 = 21.52% (v/v)) on 3rd stage larvae of housefly were extracted and purified using an activated Thiol Sepharose® for thiolated protein purification. Two dimensional gel electrophoresis was used for visualizing and analyzing expression of cytosolic and thiolated proteins. Protein spots with more than 5 fold of expression change were identified using liquid chromatography- tandem mass spectrometry (LC-MS/MS). The cytosolic proteins were actin, tropomyosin, ubiquitin, arginine kinase, pheromone binding protein/general odorant binding protein, and ATP: guanidino phosphotransferase. The thiolated proteins with more than 5 fold change in expression as an effect to the acute treatment were fructose bisphosphate aldolase, short chain dehydrogenase and lactate/malate dehydrogenase. The proteins identified in the study should provide vital information for future reference in oxidative stress defence and response occurring in houseflies.
Tritrichomonas foetus is known to cause chronic diarrhea in the feline species in many different regions of the world. However, there is a paucity of information on T. foetus among cats in Malaysia. This study was conducted to determine the prevalence of Tritrichomonas foetus in the pet and stray cat population in Klang Valley, Malaysia. A total of 201 pet and stray cats' fecal samples were collected in Klang Valley. 24 samples were cultured in the InPouch® TF Feline to observe for motile trophozoites. A nested PCR protocol was used to screen for T. foetus in the collected samples. The prevalence of T. foetus in the cat population in Klang Valley was 33%. There was no association between Tritrichomonas infection and age, sex, breed or management of the cats. However, statistical analysis revealed that stray cats were more likely to be infected with T. foetus compared to pet cats. This study confirmed for the first time the presence of T. foetus among the cat population in Klang Valley, Malaysia.
The aim of this study was to evaluate the prevalence of enteroparasitic infections in students and their hormonal and immunological repercussions on physical development. Students of basic education of both sexes were evaluated. Parasitological stool tests were performed using the Hoffman and Kato-Katz methods. The students were divided into two groups: a control group (negative parasitological examination, N=25) and an infected group (positive parasitological test, N=25). Anthropometric variables (height, weight, and BMI), concentrations of hormones (melatonin and cortisol), cytokine/chemokine levels (IL-1β, IL-6, IL-8, IL-10, IL-12, IL-17 and TNF-α) and physical performance (aerobic capacity, upper- and lower-limb muscle strength and abdominal performance) were evaluated. The prevalence of parasitic infection among the students was 7.98%. No anthropometric differences were observed among the groups. IL-2 and TNF-α levels were higher and IL-8 levels were lower in serum from students who were positive for parasitic infection. Serum from students who were positive for parasitic infection showed higher levels of melatonin than that from parasitenegative students. No differences were observed in cortisol levels. Students who were positive for parasitic infection presented greater lower-limb strength and lower abdominal performance than parasite-negative students. In the parasitic infection group, IL-12 was positively correlated with melatonin. In the parasitic infection group, IL-8 showed a positive correlation with aerobic capacity, while IL-17 and TNF-α showed a positive correlation with abdominal performance. These data suggest that parasitic infections determine the profile of inflammatory cytokines and that melatonin may be involved in the control of this process to minimize tissue damage. Additionally, students' difficulty in practising physical exercises can be an indication of enteroparasitic infection.
Canine demodicosis is a common skin disorder with multiple risk factors, including age and breed predisposition. There is relatively limited information about the risk factors for canine demodicosis in large canine populations. This retrospective case-control study was conducted by searching the electronic records of dogs with skin lesions for the presence of Demodex mites in skin scrapings. Diagnosis of demodicosis was based on the presence of skin lesions and mites in skin scrapings. Multivariate analysis was conducted using logistic regression analysis to estimate the relative risk and odds ratio of variables hypothesized to influence the risk of canine demodicosis, such as age, sex, breed, season, and parasitic infection. The results of multivariate logistic regression analysis showed a positive correlation between the dogs' age and demodicosis. Dogs older than three years, as well as puppies, had a high risk of demodicosis (P0.05). Breeds with the greatest association (odds ratio) with demodicosis included the American Staffordshire Terrier (OR=0.9) and Moscow Watchdog (OR=0.2). The presence of intestinal parasites, such as Diphyllobothrium latum, was significantly associated with demodicosis.
Reduced susceptibility in Burkholderia pseudomallei during carbapenem therapy may lead to treatment failure. We isolated a clinical strain that had developed reduced susceptibility to carbapenems while on treatment. After reviewing the patient's clinical notes, the initial isolate (BUPS01/14) was exposed to carbapenem in vitro to mimic the clinical scenario. The stability of susceptibility of the carbapenem-exposed strain (BUPS01/14R) was examined by serial subculture in antibiotic-free broth. Biochemical and morphological comparison was performed by the VITEK® system and electron microscopy. MICs increased 32-fold following carbapenem exposure and became stable in the antibiotic-free environment. On electron microscopic examination, the BUPS01/14R cells were smoother and less wrinkled compared to BUPS01/14 cells. This report highlights a potential anti-melioidosis treatment failure due to the emergence of resistance while on carbapenem monotherapy. Further study of this strain is necessary to understand the mechanism of resistance at a molecular level.
To characterize the production and larvicidal activity of Xenorhabdus stockiae KUT6 Petroleum ether extracts from Luria Broth and induced Quorum sensing medium containing N-3- oxododecanoyl Homoserine Lactone inducer against dengue vector Aedes aegypti. The Galleria mellonella larvae were reared for the isolation of Steinernema saimkayi symbiont Xenorhabdus stockiae KUT6 from Cucumber field soil sample in NBTA. Then for the extraction of compounds the KUT6 strains were cultured in Luria Broth and Quorum Sensing optimized media using N-3-oxododecanoyl homoserine lactone inducer. The larvicidal activity of Xenorhabdus stockiae KUT6 of petroleum ether extracts were bioassayed against 4th instar Aedes aegypti dengue vector. The maximum rate of mortality were recorded of the samples A-24h, B-48h, C-72h, A1-24h, B1-48h, C1-72h at different concentrations 50 µg/ml, 100 µg/ml and 150 µg/ml respectively for 24h to 72h of exposure treatment. The morphological characteristics of Xenorhabdus stockiae KUT6 in NBTA were red core colonies with blue background surrounded by zone of inhibition. After 24h exposure maximum rate of 100% mortality of Aedes aegypti 4th instar larvae was attained when treated with sample C1-72h 50 µg/ml of the petroleum ether extracts of quorum sensed medium whereas the sample C 72h petroleum ether extracts of KUT6 cultured in Luria broth recorded 100% mortality at 150 µg on 24h exposure indicates enhancement in the product yield. The study assures the use of Xenorhabdus stockiae KUT6 petroleum ether extracts as biocontrol agent could be beneficial for the control of dengue vectors.
Ticks are vectors of bacteria, protozoa and viruses capable of causing serious and life threatening diseases in humans and animals. Disease transmission occurs through the transfer of pathogen from tick bites to susceptible humans or animals. Most commonly known tick-borne pathogens are obligate intracellular microorganisms but little is known on the prevalence of culturable pathogenic bacteria from ticks capable of growth on artificial nutrient media. One hundred and forty seven ticks originating from dairy cattle, goats and rodents were collected from nine selected sites in Peninsular Malaysia. The culture of surfacesterilized tick homogenates revealed the isolation of various pathogenic bacteria including, Staphylococcus sp., Corynebacterium sp., Rothia sp., Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli and Bacillus sp. and its derived genera. These pathogens are among those that affect humans and animals. Findings from this study suggest that in addition to the regular intracellular pathogens, ticks could also harbor extracellular pathogenic bacteria. Further studies, hence, would be needed to determine if these extracellular pathogens could contribute to human or animal infection.
The bioactivity of R. nasutus leaf extracts was assessed on Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Streptococcus pyogenes, Vibrio parahaemolyticus, Enterobacter aerogenes, Proteus mirabilis, and Klebsiella pneumoniae. Crude chloroform, petroleum ether, ethyl acetate, ethanol and methanol extracts were screened by disc diffusion method. Promising crude extract was further subjected to the column fractionation followed by the screening of the antibacterial activity of individual fractions. Biologically active pure fraction was subjected to the advanced analytical studies like HPLC, LC-MS, IR and NMR for characterisation of the bioactive compound. Ethanolic extract exhibited the maximum antibacterial activity against Klebsiella pneumoniae with the maximum of 35±0.42 mm zone of inhibition. The biologically potent column fraction from ethanol extract with 40±0.42 mm zone of inhibition upon subject to the HPLC, LC-MS, IR and NMR revealed that the active compound is rhinacanthin-C, a naphthoquinone.
Malaria is one of the most dangerous infectious diseases due to its high infection and mortality rates, especially in the tropical belt. Plasmodium falciparum (P. falciparum), the most virulent malaria parasite in humans, was recently reported to develop resistance against the final efficient antimalarial drug, artemisinin. Little is known about the resistance mechanisms, which further complicates the problem as a proper counteraction is unable to be taken. Hence, the understanding of drug mode of action and its molecular target is valuable knowledge that needs to be considered to develop the next generation of antimalarial drugs. P. falciparum protein kinase (Pf PK) is an attractive target for antimalarial chemotherapy due to its vital roles in all P. falciparum life stages. Moreover, overall structural differences and the presence of unique Pf PKs that are absent in human kinome, suggesting specific inhibition of Pf PK without affecting human cells is achievable. To date, at least 86 eukaryotic protein kinases have been identified in P. falciparum kinome, by which less than 40 were validated as potential targets at the erythrocytes stage. In this review, recent progress of the furthest validated Pf PKs; Pf Nek-1, Pf CDPK1, Pf CDPK4, Pf PKG, and Pf CLK-3 will be briefly discussed.
Dengue has been a public health concern for many years in Malaysia. Having knowledge on the current circulating dengue serotypes and population of vector mosquitoes is key in controlling outbreaks and future outbreak predictions. The current study reports the first study on detecting dengue virus serotypes in the Aedes mosquito population in Sibu and Miri divisions of Sarawak. Mosquito samples were collected at selected localities from September 2016 to December 2017. Localities were selected mainly focussing on urban residential areas. The mosquitoes collected comprises of the field-caught adults and immatures collected from artificial and natural water containers. Collected mosquitoes were identified to species level and screened for the presence of dengue virus using conventional reverse transcription polymerase chain reaction (RT-PCR). Dengue virus serotype 2 (DENV-2) was identified in 3 pools of field-caught female Aedes albopictus adults collected from Jalan Tong Sang, Sibu, Sibu Lake Garden, and Taman Ceria, Permyjaya, Miri, respectively. DENV-2 was also detected in one pool of adult male Ae. albopictus emerged from immatures collected from Taman Ceria, Permyjaya, Miri. The findings in this study revealed that Ae. albopictus was the main species colonizing the study areas, and the current circulating dengue virus serotype was DENV-2. This study also reports the first natural evidence of transovarial transmission of dengue in the natural population of Ae. albopictus within the study area and provides information as reference for further vector-pathogen studies.
Contagious bovine pleuropneumonia (CBPP) is a highly contagious disease of cattle caused by Mycoplasma mycoides subsp. mycoides. It is characterized by anorexia, fever, dyspnea, polypnea, cough, and nasal discharges. Gross lesions in the lung such as marbling, sequestra, thickening of interlobular septa, and consolidation are evident. Serological tests including complement fixation test and competitive enzyme-linked immunosorbent assay and molecular tests such as polymerase chain reactions are used for diagnostic purposes. In this study, lung samples of suspected large ruminants (cattle n=560, buffalo n=293) were collected from abattoirs of three districts of Punjab namely Lahore, Kasur and Jhang. PCR was performed with specific primers, targeting the 16S ribosomal RNA gene to detect the positive cases. The results indicated that 49 samples (8.75%) of cattle were positive, with maximum prevalence was observed in Jhang with 16 positive samples (10.06%), but CBPP was not detected in any buffalo sample. High prevalence of disease was seen in cattle of more than seven years of age, in female cattle, and in cross-bred cattle. Age and gender were found significantly associated (P<0.05) with the prevalence of the disease. Gene sequencing of identified 5 isolates of Mycoplasma mycoides subsp. mycoides had more than 99% similarities with the strains isolated from China, Italy, Australia and Tanzania and were categorized into a monophyletic group but strain isolated from Portugal had more than 55% variable regions, hence clustered separately. This study confirms the presence of contagious bovine pleuropneumonia in the country which can be a threat to the livestock export market and warrants the implementation of control measures to mitigate the economic losses associated with the disease.
Storage of dengue virus (DENV) culture stocks in -80°C is a common laboratory practice to maintain the viability of the virus for long-term usage. However, the efficiency of this method could still be hindered by multiple factors. In our laboratory, we observed a constant and substantial deterioration in the titer of DENV in Vero culture supernatant stored in -80°C. Such incident had badly hampered the laboratory work and prompted an investigation to determine the cause. DENV isolates representing all four serotypes were propagated and the culture supernatants were harvested and stored in aliquots of original stock and 10 fold dilutions (10-1 -10-4). DENV titer in these stocks was determined prior to storage and reassessed on the third and sixth month of storage by focus forming unit assay (FFUA). The result demonstrated a constant preservation of titer ranging from 104 ffu/ml to 105 ffu/ml in the diluted DENV virus culture stocks of 10-1, and 10-2 of DENV1-4, a minor reduction of titer from 103 ffu/ml to 102 ffu/ml at dilution 10-3 for DENV4 only and complete deterioration in undiluted culture stock and lower dilution (10-4) within 6 months of storage in -80°C for all serotypes. It is recommended that propagated DENV in Vero cells are stored in 10 fold dilutions as compared to the original form to preserve the titer for long-term usage.
The sand fly Phlebotomus papatasi is an important disease-bearing vector. Five entomopathogenic nematodes (EPNs) - Steinernema carpocapsae DD136, Steinernema sp. (SII), S. carpocapsae all, S. abbasi, and Heterorhabditis bacteriophora HP88 - were applied as biocontrol agents against the late third instar larvae of P. papatasi. In addition, the effect of toxin complexes (TCs) of Xenorhabdus nematophila and Photorhabdus luminescens laumondii bacteria was evaluated. Results revealed that S. carpocapsae DD136 was the most virulent species followed by Steinernema sp. (SII) and S. carpocapsae all where LC50 were 472, 565, 962 IJs/ml, respectively. Also, the crude TCs were slightly more active and toxic than their fractionated protein. Histopathological examination of infected larvae with H. bacteriophora HP88 showed negative effect on their midgut cells. In conclusion, EPNs with their symbiotic bacteria are more effective as biocontrol agents than the crude or fractionated TCs against sand fly larvae.
Burkholderia pseudomallei is the etiologic agent of melioidosis, a major cause of community-acquired pneumonia and sepsis in the endemic areas. The overall mortality of patients with severe melioidosis remains high due to severe sepsis attributed to overwhelming inflammatory cytokine response in spite of recommended antibiotic therapy. It is crucial that therapeutic approaches beyond just effective antibiotic treatment such as adjunct therapy be considered to mitigate the dysregulated inflammatory signaling and augment host defenses. In an acute B. pseudomallei infection model, we have previously demonstrated that treatment with anti-malarial drug, chloroquine, modulated inflammatory cytokine levels and increased animal survivability via Akt-mediated inhibition of glycogen synthase kinase-3β (GSK3β). GSK3β is a downstream effector molecule within the phosphatidylinositol 3-kinase (PI3K)/ Akt axis which plays a pivotal role in regulating the production of pro- and anti-inflammatory cytokines. Here we evaluate the effect of chloroquine treatment in combination with a subtherapeutic dose of the antibiotic doxycycline on animal survivability, cytokine levels and phosphorylation states of GSK3β (Ser9) in a murine model of acute melioidosis infection to investigate whether chloroquine could be used as an adjunct therapy along with doxycycline for the treatment of melioidosis. Our findings revealed that 50 mg/kg b.w. chloroquine treatment together with a dose of 20 mg/kg b.w. doxycycline improved survivability (100%) of mice infected with 3 X LD50 of B. pseudomallei and significantly (P<0.05) lowered the bacterial loads in spleen, liver and blood compared to controls. B. pseudomallei-infected mice subjected to adjunct treatment with chloroquine and doxycycline significantly (P<0.05) reduced serum levels of pro-inflammatory cytokines (TNF-α, IFN-γ and IL-6) but increased levels of antiinflammatory cytokines (IL-4 and IL-10). Western blot analysis demonstrated that the intensities of pGSK3β (Ser9) in liver samples from mice treated with chloroquine and doxycycline combination were significantly (P<0.05) higher suggesting that the adjunct treatment resulted in significant inhibition of GSK3β. Taken together the bacteriostatic action of doxycycline coupled with the cytokine-modulating effect of chloroquine gave full protection to B. pseudomallei-infected mice and involved inhibition of GSK3β. Findings from the present study using B. pseudomallei-infected BALB/c mice suggest that chloroquine is a plausible candidate for repurposing as adjunct therapy to treat acute B. pseudomallei infection.