This study was carried out in an oil palm plantation in Bandar Baharu, Kedah using monkey carcasses and focuses in documenting the decomposition and dipteran colonization sequences in 50 days. This is the first study of Diptera associated with the exploitation of carcasses conducted in the north of peninsular Malaysia during the dry and wet seasons thereat. During the process of decomposition in both seasons, five phases of decay were recognized namely fresh, bloated, active decay, advance decay and dry remain. In this decomposition study, biomass loss of carcass occurred rapidly during the fresh to active decay stage due to the colonization and feeding activity of the Diptera larvae. The duration of the fresh and bloated stages of decay were the same in wet and dry seasons but later stages of decay were markedly shorter during the wet season. Twenty one species of adult Diptera were identified colonizing carcasses in the study period. Among the flies from the family Calliphoridae, Chrysomya megacephala Fabricius and Chrysomya nigripes Aubertin were recognized as the earliest arrivals on the first day of exposure. Adult Ch. nigripes was abundant for approximately two weeks after placement of the carcasses. By comparing the percentages of adults collected during the study period, the calliphorids abundance in percentages in wet season was 50.83%, but in dry season, the abundance was only about 35.2%. In contrast, the percentage of Sphaeroceridae in wet season was only 3.33%, but in the dry season, the abundance was 20.8%. Dipteran in family Phoridae, Piophilidae, Sepsidae, Drosophilidae and Dolichopodidae colonized the carcasses for a long period of time and were categorized as long term colonizers.
This study is the first report on the occurrence of Giardia and Cryptosporidium (oo)cysts in recreational rivers water from Malaysia. It was carried out in water samples at two rivers, 'Sungai Congkak' and 'Sungai Batu', located in Selangor State. The occurrence of both Giardia lamblia and Cryptosporidium parvum (oo)cysts was higher in Sungai Congkak (50% or 15/30 and 10% or 3/30 respectively) than Sungai Batu (16% or 5/30 and 3.3% or 1/30 respectively). The mean density of cysts/L was 0.72 in Sungai Congkak and 0.023 in Sungai Batu, and that of oocysts/L was 0.023 in Sungai Congkak and 0.0033 in Sungai Batu, showing that the occurrence of Giardia was higher and more frequent than Cryptosporidium in both rivers. Sungai Congkak also showed higher faecal coliforms count (ranging from 0.48x10³ to 73x10³ CFU/100 mL) than Sungai Batu (0.41x10³ to 16x10³ CFU/100 mL). On the other hand, the Giardia and Cryptosporidium (oo)cysts and faecal coliforms were more concentrated at the downstream station, followed by midstream and upstream stations which might be due to human factors where settlements and recreation areas were located around and between midstream and downstream stations. The (oo)cysts and faecal coliforms also increased during public holidays due to the significantly higher number of visitors (bathers) compared with the week days. All the parameters (physical, faecal coliforms and rainfall) did not show consistent significant correlation (based on r values of Pearson correlation analysis) with both protozoa, therefore these parameters are not suitable as indicator for the presence of Giardia and Cryptosporidium (oo)cysts in both rivers.
Matched MeSH terms: Cryptosporidium/growth & development; Giardia/growth & development
Ovitrap surveillance was initiated for eight continuous weeks to determine the distribution and abundance of Aedes sp. mosquitoes in the University of Malaya campus, Kuala Lumpur, and the impact of meteorological conditions on the Aedes populations. Two study areas within the campus were selected: Varsity Lake and Seventh Residential College. The abundance of Aedes populations in Varsity Lake was indicated by ovitrap index (OI) which ranged from 60.00%-90.00%. The mean number of larvae per ovitrap of Aedes albopictus in Varsity Lake ranged from 11.23+/-2.42-43.80+/-6.22. On the other hand, the outdoor OI for Seventh Residential College ranged from 73.33%-93.33%, respectively, while the mean number larvae per ovitrap for this area ranged from 19.33+/-4.55-35.27+/-5.46, respectively. In addition, the indoor OI of Seventh Residential College ranged from 0.00%-30.00%, while the mean number of larvae per ovitrap for Ae. albopictus ranged from 0-5.90+/-3.55. There was no significant difference (p>0.05) of Ae. albopictus population between Varsity Lake and Seventh Residential College. The studies showed a correlation between OI and mean number of larvae per ovitrap for outdoor Ae. albopictus populations in Varsity Lake and Seventh Residential College (r=0.794). There was also a correlation between the mean larvae number per ovitrap of Ae. albopictus obtained from eight weeks indoor ovitrap surveillance in Seventh Residential College with rainfall (r=0.584). However, there was no correlation between the mean larvae number per ovitrap of Ae. albopictus in both study areas with temperature and relative humidity. Aedes aegypti mosquitoes were found neither indoor nor outdoor in both study areas. This study indicated that the principal dengue vector in the university campus was most likely Ae. albopictus.
Larvae of the Synthesiomyia nudiseta (Wulp) were collected from a decomposed human corpse at the Department of Forensic Medicine, Penang Hospital. A colony of this species was established and the eggs were collected for rearing. The developmental times, rearing temperatures, and relative humidity were recorded twice daily from the time the eggs collected until adult emergence. An average of 5 larvae were randomly collected from the rearings twice daily, warm-water killed and preserved in Kahle's solution. The larval instar stages were determined by observing the number of posterior spiracular slits and the length of the preserved larvae were measured. When the larval life cycle was completed, the accumulated developmental times were calculated. A total of 8 replicates were carried out. The temperature of the rearing room was 28.5+/-1.5 degrees Celcius while the relative humidity was within 67-85%. The total developmental time for S. nudiseta was 322+/-19 hours (13.4+/-0.8 days).
Larvae and adults of Culex quinquefasciatus were used for the test undertaken for malathion resistant strain (F61 - F65) and permethrin resistant strain (F54 - F58). The results showed that the LC50 for both malathion (F61 - F65) and permethrin (F54 - F58) resistant Cx. quinquefasciatus increased steadily throughout the subsequent five generations, indicating a marked development of resistance. The adult female malathion resistant strain have developed a high resistance level to malathion diagnostic dosage with a resistance ratio of 9.3 to 17.9 folds of resistance compared with the susceptible Cx. quinquefasciatus. Permethrin resistance ratio remained as 1.0 folds of resistance at every generation. It was obvious that malathion resistance developed at a higher rate in adult females compared to permethrin. Enzyme-based metabolic mechanisms of insecticide resistance were investigated based on the biochemical assay principle. From the results obtained obviously shows that there is a significant difference (p < 0.05) in esterase level in both malathion and permethrin selected strains. Female malathion selected strain has the higher level of esterase activity compared to the female permethrin selected strain at (0.8 to 1.04) alpha-Na micromol/min/mg protein versus (0.15 to 0.24) alpha-Na micromol/min/mg protein respectively. This indicated increased level of non-specific esterase is playing an important role in resistance mechanism in female malathion selected strain. Permethrin selected strain exhibited non-specific esterase activity at a very low level throughout the different life stages compared to malathion selected strain. This study suggests that life stages play a predominant role in conferring malathion and permethrin resistance in Cx. quinquefasciatus.
This preliminary study was carried out in a palm oil plantation in Tanjung Sepat, Selangor in 17 May 2007 by using pig (Sus scrofa) as a carcass model in forensic entomological research. A 3 month old pig (8.5 kg) that died of pneumonio was placed in the field to observe the decomposition stages and the fauna succession of forensically important flies. Observation was made for two weeks; two visits per day and all climatological data were recorded. The first visitor to the pig carcass was a muscid fly, seen within a minute, and followed by ants and spiders. Within half an hour, calliphorid flies came over. On the second day (fresh), few calliphorid and sarcophagid flies were found on the carcass. Two different species of moths were trapped in the hanging net. The first larva mass occurred on the third day (bloated) around the mouthpart, with some L1 and L2 found in the eyes. Reduvid bugs and Staphylinidae beetles were recovered on the fourth day (active decay), and new maggot masses occurred in the eyes and anus. L3 larvae could be found beneath the pig carcass on the fourth day. On the fifth day (active decay), new maggot masses were found on neck, thorax, and hind legs. Advance decay occurred on the sixth day with abundant maggots covering all over the body. The main adult fly population was Chrysomya megacephala (day 2 to day 6), but the larvae population was mainly those of Chrysomya rufifacies (day 4 to day 14). The dry stage began on the eighth day. Hermetia illucens adult was caught on day-13, and a larvae mass of Chrysomya rufifacies was seen burrowing under the soil. This forensic entomological research using pig carcass model was the first record in this country.
This study was conducted to examine the effect of malathion on the development of Chrysomya megacephala. A total of 12 adult Sprague-Dawley rats was divided into 4 groups. Each animal in the 4 groups was given orally 0 (control), 10, 25 and 50ml/kg body weight of malathion, respectively. Chrysomya megacephala larvae were then allowed to grow on the liver of carcass. Larvae development was estimated by means of weight and length, time of adult emergence and survival rate. Results indicated that for the first 6 to 30 hours, larvae from control group developed more rapidly than larvae feeding on tissue containing malathion. However, the 3 doses of malathion did not exhibit significant impact on larvae length and weight. The time required for adult emergence was significantly greater for malathion-treated colony which was 10 days compared to 7 days in control colony. Control larvae of C. megacephala had higher survival rate compared to larvae exposed to the three different doses of malathion. Analysis of the tissues indicated that all rats and fly samples were positive for malathion. Malathion concentration was highest in liver. It was concluded that the presence of malathion altered the development rate of C. megacephala and thus disrupted normal postmortem interval estimation.
Matched MeSH terms: Diptera/growth & development; Larva/growth & development
A study of diurnal and nocturnal distribution of flies was conducted in Putrajaya. Six different ecological habitats were selected, namely: botanical garden, lake-area, administration building, wetland, jungle fringes and housing areas. Two different type of traps, cylinderical and rectangular in shape were used in the study. Baits used in these traps were yeast, sugar, salted fish, shrimp paste and fresh liver. Traps were placed at the sites throughout the diurnal and nocturnal periods. The time for sunrise and sunset was determined using a Geographical Positioning System gadget (GARMIN) at the sites. Both type of traps were equally effective in trapping flies. There was no significant difference between both types of traps in their ability to trap flies (p > 0.05). A total of 1,534 flies were collected and identified from both types of trap using the multiple baits and habitats. The collection consisted of 23 species of flies classified under 6 families. The highest number of flies were caught from the lake-area followed by botanical garden, administration building, housing areas, wetland and jungle fringes. The most dominant species was Chrysomya megacephala, followed by species of Sarcophagidae and Musca domestica. Diurnal period had more numbers of flies (81.55%) compared to the nocturnal periods (18.45%). Some species of flies were strictly diurnal, some exibited both diurnal and nocturnal activities while only one species was strictly nocturnal.
Matched MeSH terms: Houseflies/growth & development
This entomological study was conducted in a man-made freshwater pond in a palm oil plantation in Tanjung Sepat, Selangor from 23 July 2007 by using pig (Sus scrofa) as a carcass model. A 1.5 month old piglet (5 kg), which died of asphyxia after being accidentally crushed by its mother, was thrown into a pond. Observation was made for ten days; one visit per day and climatological data were recorded. On the first two days, the piglet carcass sunk to the bottom of the pond. The carcass floated to the surface on the third day but no fly activities were seen. The blow fly, Chrysomya megacephala and Chrysomya rufifacies started to oviposit on the fourth day. Other than adult flies, a spider (Arachnida) was also observed on the carcass. Bubbles accumulated at the mouthpart, and the abdomen was greenish black. A lot of blow fly eggs were seen on the body surface on the fifth day (floating decay), along with first and second instars C. megacephala crawling under the piglet's skin. On the sixth day, adult blow fly, C. megacephala,and C. rufifacies,and muscid flies, Ophyra spinigera and Musca domestica were observed on to the carcass. High numbers of first and second instars of flies were observed wandering around the body surface with C. megacephala larvae being the predominant species. Two prominent maggot masses occurred on seventh and eighth days. Bloated deterioration stage began on day eighth exposing rib bones, humerus bones and intestines. Carcass was partially sinking and the maggot masses were at the water level. On day ninth, the carcass was partially sinking and three maggot masses were observed on the exposed surface. There were very few adult flies, including a scarab beetle was sighted on the carcass at this stage. The carcass along with the maggots sunk on day tenth, leaving an oily layer on the water surface.
Insects found associated with corpse can be used as one of the indicators in estimating postmortem interval (PMI). The objective of this study was to compare the stages of decomposition and faunal succession between a partially burnt pig (Sus scrofa Linnaeus) and natural pig (as control). The burning simulated a real crime whereby the victim was burnt by murderer. Two young pigs weighed approximately 10 kg were used in this study. Both pigs died from pneumonia and immediately placed in an oil palm plantation near a pig farm in Tanjung Sepat, Selangor, Malaysia. One pig was partially burnt by 1-liter petrol while the other served as control. Both carcasses were visited twice per day for the first week and once thereafter. Adult flies and larvae on the carcasses were collected and later processed in a forensic entomology laboratory. Results showed that there was no significant difference between the rate of decomposition and sequence of faunal succession on both pig carcasses. Both carcasses were completely decomposed to remain stage after nine days. The species of flies visiting the pig carcasses consisted of blow flies (Chrysomya megacephala, Chrysomya rufifacies, Hemipyrellia ligurriens), flesh fly (Sarcophagidae.), muscid fly (Ophyra spinigera), soldier fly (Hermetia illucens), coffin fly (Phoridae) and scavenger fly (Sepsidae). The only difference noted was in the number of adult flies, whereby more flies were seen in the control carcass. Faunal succession on both pig carcasses was in the following sequence: Calliphoridae, Sarcophagidae, Muscidae, Phoridae and lastly Stratiomyidae. However, there was overlap in the appearance of members of these families. Blowflies continued to oviposit on both carcasses. Hence postmortem interval (PMI) can still be estimated from the partially burnt pig carcass.
The inhibitory activity of diflubenzuron, a chitin synthesis inhibitor, on the ecdysis of Aedes sp. larvae was evaluated in earthen jars and automobile tires. Two formulations of diflubenzuron were used in this study: Dimilin(R) WP (wettable powder), 25% and Dimilin GR (granular), 2%. The equivalent rate of 25 g/ha, 50 g/ha and 100 g/ha active ingredients for both WP and GR formulations were used in this study. Generally, at the higher dosage of 100 g/ha, both formulations were more effective against Aedes mosquitoes. On the whole, the WP formulation appeared to perform better than the GR formulation in terms of residual activity.
Matched MeSH terms: Aedes/growth & development; Insect Vectors/growth & development
The standard laboratory strain was found to be heterozygous for susceptibility. Hence, an attempt was made to obtain a homozygous susceptible strain in Culex quinquefasciatus (Say) using single raft sib-selection method. Lab-bred females of Cx. quinquefasciatus from insectariums, Unit of Medical Entomology were used in the experiment. After blood feeding Cx. quinquefasciatus mosquitoes laid eggs in raft form, ten rafts selected randomly for the test. Each egg raft was introduced into a plastic tray from number one to number ten. Twenty-five third stage larvae from each tray were exposed to 17.5 microl from 500mg/l malathion in a paper cup label number 1 to number ten. In the bioassay, which had 100% mortality, the respective larva in that particular tray was bred to adult stage for the following generation. Less than 7days old female mosquitoes that emerged from F(0) were used in the test. The F(0) and the subsequent adult and larval stage generations were subjected to adult and larval bioassay. After selection for about 10 generations, a homozygous susceptible strain in Cx. quinquefasciatus was obtained.
Vegetative proteins from Malaysian strains of Bacillus thuringiensis israelensis strains (Bt 11, Bt 12, Bt 15, Bt 16, Bt 17, Bt 21 and Bt 22) and Bacillus sphaericus H-25 strains (Bs 1 and Bs 2) were screened for haemolytic, cytotoxic and larvicidal activity. SDS-PAGE profiles of the Bacillus thuringiensis strains studied consistently showed major bands of 33-37 kDa and 47 kDa. Bt 16 also showed two bands of 66 kDa and 45 kDa similar to the previously reported binary vegetative protein, Vip1Ac (66 kDa) and Vip 2Ac (45 kDa). Both the Bacillus sphaericus strains showed a 35 kDa band that was similiar to a previously reported vegetative protein, the Mtx2 protein. Bs 2 also contains a 37 kDa band, similar to another vegetative protein, the Mtx 3 protein. With the exception of Bt 17 and Bt 21, vegetative proteins from all Bacillus thuringiensis and Bacillus sphaericus strains were highly haemolytic to human erythrocytes, causing more than 75% haemolysis at the highest concentration of 200 microg/ml. High haemolytic activity was associated with high cytotoxic activity with most of the haemolytic strains being indiscriminately cytotoxic to both CEM-SS (human T lymphoblastoid) and HeLa (human uterus cervical cancer) cell lines. Interestingly, the less haemolytic vegetative proteins from Bt 17 and Bt 21 demonstrated cytotoxic activity comparable to that of the highly haemolytic vegetative proteins. Bt 21 displayed toxicity towards both cell lines while Bt 17 was more toxic towards CEM-SS cells. Bioassay against Aedes aegypti and Culex quinquefasciatus larvae revealed that vegetative proteins from the Bacillus thuringiensis strains had activity against both species of larvae but vegetative proteins from Bacillus sphaericus were weakly larvicidal towards Cx. quinquefasciatus only.
Matched MeSH terms: Aedes/growth & development; Culex/growth & development
Larvae obtained from Taman Samudera (Gombak, Selangor), Kampung Banjar (Gombak, Selangor), Taman Lembah Maju (Cheras, Kuala Lumpur) and Kampung Baru (City centre, Kuala Lumpur) were bioassayed with diagnostic dosage (0.012 mg/L) and operational dosage (1 mg/L) of temephos. All strains of Aedes aegypti and Aedes albopictus showed percentage mortality in the range of 16.00 to 59.05 and 6.4 to 59.50 respectively, after 24 hours. LT50 values for the 6 strains of Ae. aegypti and Ae. albopictus were between 41.25 to 54.42 minutes and 52.67 to 141.76 minutes respectively, and the resistance ratio for both Aedes species were in the range of 0.68 to 1.82 when tested with operational dosage, 1 mg/L temephos. These results indicate that Aedes mosquitoes have developed some degree of resistance. However, complete mortality for all strains were achieved after 24 hours when tested against 1 mg/L temephos.
Matched MeSH terms: Aedes/growth & development; Insect Vectors/growth & development
Larvae of Aedes aegypti and Aedes albopictus obtained from 6 consecutive ovitrap surveillance (OS) in Taman Samudera and Kg. Banjar were evaluated for their susceptibility to temephos. Larval bioassays were carried out in accordance with WHO standard methods, with diagnostic dosage (0.012 mg/L) and operational dosage (1 mg/L) of temephos respectively. Aedes aegypti and Ae. albopictus obtained from six OS in Taman Samudera showed resistance to diagnostic dosage of temephos with percentage mortality between 5.3 to 72.0 and 9.3 to 56.0, respectively, while Ae. aegypti and Ae. albopictus obtained from Kg. Banjar showed resistance to temephos with percentage mortality between 16.0 to 72.0 and 0 to 50.6, respectively. Only two strains of Ae. aegypti from Kg. Banjar were susceptible to temephos with 93.3% (OS 2) and 100% (OS 3) mortality. The 50% mortality at lethal time (LT50) for all strains of Ae. aegypti and Ae. albopictus tested against operational dosage of temephos showed range between 36.07 to 75.69 minutes and 58.65 to 112.50 minutes, respectively, and complete mortality was achieved after 24 hours. Our results indicated that there is weekly variations of the resistance status for Ae. aegypti and Ae. albopictus. Aedes susceptibility to temephos is changing from time to time in these two study sites. It is essential to continue monitoring the resistance of this vector to insecticides in order to ensure the efficiency of program aimed at vector control and protection of human health.
Matched MeSH terms: Aedes/growth & development; Insect Vectors/growth & development
A study to determine the contribution of Giardia cysts and Cryptosporidium oocysts from cattle farms was carried out at the Langat Basin. This study investigated the contribution of cattle farms, located near Sungai Langat and Sungai Semenyih, towards river contamination with these cysts and oocysts. The findings showed that out of 24 samples of water taken from Sungai Semenyih, 4.2% was positive for Giardia cysts with a concentration of 1.3 cysts/L and 20.8% were positive with Cryptosporidium oocysts with a range of 0.7 - 2.7 oocysts/L. At Sungai Langat, from the 43 samples taken, 23.3% were positive for Giardia cysts with a range of 1.5 - 9 cysts/L whereas 11.6% were positive with Cryptosporidium oocysts with a range of 2.5 - 240 oocysts/L. Isolation of cysts and oocysts in bovine faecal materials revealed that 14.6% of faecal samples were positive for Giardia cysts which had a range of 75 - 1.3x104 cysts/g and 25% were positive for Cryptosporidium oocysts with a range of 50 - 3.9x105 oocysts/g. From the cattle wastewater, 98% were positive with oocysts and 6.7% with cysts. The concentrations were between 20 - 3.1x103 oocysts/mL for Cryptosporidium and 4 - 75 cysts/mL for Giardia. Given that the prevalence of Cryptosporidium and Giardia are high amongst the cattle and the positive findings of the (oo)cysts in the river samples, it could be deduced that there is a very high possibility of the cattle farms contaminating the river with Giardia cysts and Cryptosporidium oocysts. Viability study of Cryptosporidium oocysts in the surrounding soil and pond within the cattle farm showed that the viability of Cryptosporidium oocysts decreased with time. It was estimated that it will take 52 days for all the oocysts from both environment to be non-viable. With a viability rate of approximately 2 months in a cattle farm setup, river water contaminated with Cryptosporidium oocysts has a high chance of acting as an agent of transmission. As cattle farms are also inhabited by the owners and their families, this problem may pose a threat to humans (e.g. children) especially if they are dependent on the river water as their source of water for their daily activities.
In the present study we examined the effect of E. longifolia methanol extract (TA164) on the GSH levels of P. falciparum infected erythrocytes and uninfected erythrocytes. Our study on parasite growth shows the IC50 and IC75 values of TA164 to be 0.17 g/ml and 6 g/ml respectively while for BSO was 25.5 g/ml and 46.5 g/ml respectively. About 95% to 100% growth inhibition of P. falciparum infected erythrocyte was observed when treated with TA164 and BSO at 16 g/ml and 64 g/ml respectively. The study on GSH contents indicated that non-infected erythrocytes treated with 6 g/ml (IC75 values) of TA164 at 24 hours incubation showed less GSH content as compared to non-treated erythrocytes. A similar observation was seen on treated trophozoite infected erythrocyte (10% parasitemia) when treated with 6 g/ml at 3 hours incubation. Analysis of the GSH contents of parasite compartments treated with TA164 at the same concentration (6 g/ml) for 3 hours incubation indicated a reduction of GSH contents. At the same concentration, TA164 did not affect the GSH contents of enriched trophozoite infected erythrocytes (60-70% parasitemia). TA164 did affect the GSH content of non-infected erythrocyte at 24 hours (accept IC50 value) as well as the parasite compartments (trophozoite infected erythrocyte and parasite itself) but fails to affect the GSH content of enriched trophozoite infected erythrocyte.
Matched MeSH terms: Plasmodium falciparum/growth & development
To determine resistance level and characterize malathion and permethrin resistance in Culex quinquefasciatus, two methods were used namely: WHO procedures of larval bioassay to determine the susceptibility of lethal concentration (LC) and adult bioassay to determine the lethal time (LT) which are resistant to malathion and permethrin. These mosquito strains were bred in the Insectarium, Division of Medical Entomology, IMR. Thousands of late fourth instar larvae which survived the selection pressure to yield 50% mortality of malathion and permethrin were reared and colonies were established from adults that emerged. Larvae from these colonies were then subjected to the subsequent 10 generations in the test undertaken for malathion resistant strain (F61 - F70) and permethrin resistant strain (F54 - F63). Selection pressure at 50% - 70% mortality level was applied to the larvae of each successive generation. The rate of resistance development and resistance ratio (RR) were calculated by LC5 0 for larval bioassay and LT50 value for adult bioassay. The lab bred Cx. quinquefasciatus was used as a susceptible strain for comparison purpose. The adult bioassay test was carried out by using diagnostic dosages of malathion 5.0%, permethrin 0.75% and with propoxur 0.1%. All bioassay results were subjected to probit analysis. The results showed that LC5 0 for both malathion (F61 - F70) and permethrin (F54 - F63) resistant Cx. quinquefasciatus increased steadily to the subsequent 10 generations indicating a marked development of resistance. The adult female malathion resistant strain have developed high resistance level to malathion diagnostic dosage with resistance ratio 9.3 to 9.6 folds of resistance. Permethrin resistance ratio remained as 1.0 folds of resistance at every generation. It was obvious that malathion resistance developing at a higher rate in adult females compared to permethrin. Female adults exposed to 2 hours of exposure period for propoxur 0.1% showed presence of cross-resistance among the both strains of mosquitoes towards propoxur and it was indicated by 70%-100% mortality at 24 hours post-recovery period.
Matched MeSH terms: Culex/growth & development; Larva/growth & development
High-fat diet (HFD) can cause hyperlipidemia, fatty liver and cardiovascular disorders. Herein, we evaluated therapeutic effects and possible underlying mechanisms of actions of Schistosoma mansoni soluble egg antigen (SEA) against experimental HFD induced dyslipidemia, hepatic and cardiovascular pathology. Forty Swiss albino mice were divided into four groups (10 each); mice fed standard diet (SD), mice fed HFD, mice fed HFD for 8 weeks then infected by S. mansoni cercaria (HFD+I) and mice fed HFD for 8 weeks then treated with SEA (HFD+SEA), all mice were euthanized 16 weeks after starting the experiment. HFD+SEA mice showed significantly (p<0.001) reduced total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG), and significantly (p<0.05) increased high-density lipoprotein cholesterol (HDL-C) comparing to HFD mice with non-significant difference with HFD+I mice group. Doppler flowmetry showed significantly (p<0.01) lower arterial resistance and significantly (p<0.05) higher blood flow velocity in HFD+SEA and HFD+I mice groups than HFD mice. HFD+SEA mice revealed improving in liver and aortic pathology and these were better than HFD+I mice group. HFD+SEA and HFD+I mice groups had less myocardium lipid deposits, but still showing some congested blood vessels. HFD myocardium revealed strong CD34+ expression on immunohistochemistry study, while that of HFD+SEA showed weak and HFD+I mice had moderate expressions. HFD+SEA mice had significantly (p<0.01) lower serum IL-1β and vascular endothelial growth factor (VEGF) and significantly (p<0.001) higher serum transforming growth factor beta 1 (TGF-β1) and IL-10 than HFD mice with non-significant difference with HFD+I mice. In conclusion, SEA lowered serum lipids, improved aortic function, decreased liver and cardiovascular pathology in HFD mice, so, it is recommended to purify active molecules from SEA to develop anti-dyslipidemic treatment.
Different miRNAs are involved in the life cycles of Schistosoma japonicum. The aim of this study was to examine the expression profile of miRNAs in individual S. japonicum of different sex before and after pairing (18 and 24 dpi). The majority of differential expressed miRNAs were highly abundant at 14 dpi, except for sja-miR-125b and sja-miR-3505, in both male and female. Moreover, it was estimated that sja-miR-125b and sja-miR-3505 might be related to laying eggs. sja-miR-2a-5p and sja-miR-3484-5p were expressed at 14 dpi in males and were significantly clustered in DNA topoisomerase III, Rap guanine nucleotide exchange factor 1 and L-serine/L-threonine ammonia-lyase. Target genes of sja-miR-2d-5p, sja-miR-31- 5p and sja-miR-125a, which were expressed at 14 dpi in males but particularly females, were clustered in kelch-like protein 12, fructose-bisphosphate aldolase, class I, and heat shock protein 90 kDa beta. Predicted target genes of sja-miR-3483-3p (expressed at 28 dpi in females but not in males) were clustered in 26S proteasome regulatory subunit N1, ATPdependent RNA helicase DDX17. Predicted target genes of sja-miR-219-5p, which were differentially expressed at 28 dpi in females but particularly males, were clustered in DNA excision repair protein ERCC-6, protein phosphatase 1D, and ATPase family AAA domaincontaining protein 3A/B. Moreover, at 28 dpi, eight miRNAs were significantly up-regulated in females compared to males. The predicted target genes of these miRNAs were significantly clustered in heat shock protein 90 kDa beta, 26S proteasome regulatory subunit N1, and protein arginine N-methyltransferase 1. To sum up, differentially expressed miRNAs may have an essential role and provide necessary information on clarifying this trematode's growth, development, maturation, and infection ability to mammalian hosts in its complex life cycle, and may be helpful for developing new drug targets and vaccine candidates for schistosomiasis.
Matched MeSH terms: Schistosoma japonicum/growth & development