ABSTRACT
Aim: This study was carried out to evaluate aquatic toxicity and surface activity of sophorolipids extracted from yeast Starmerella bombicola. Methodology: The half maximal effective concentration (EC50) values of sophorolipids were determined in three aquatic species, and the surface activity of sophorolipids in aqueous solutions was examined at EC50 concentration. Results: The EC50 of sophorolipid surfactant >473 mg l-1 was found in alga Pseudokirchneriella subcapitata, a median lethal concentration (LC50) of 64.8 mg l-1 in fish Oryzias latipes, whereas a high EC50 of 48.2 mg l-1 was noted in crustacean Daphnia magna, respectively. Sophorolipids effectively reduced the aquatic surface tension to 39 mN m-1 in O. latipes and to 41 mN m-1 in D. magna. Interpretation: These results show that sophorolipids from S. bombicola are a promising biosurfactant with an ideal balance of low aquatic toxicity and high surface activity. Key words: Aquatic toxicity, Biosurfactant, Sophorolipid, Surfactant
ABSTRACT
The study was conducted in rural school adolescent children to investigate the awareness and its association in parasitic infections in boys and girls. Of the 182 children examined 119 (65.3%) were male and 63 (34.6%) were female, age ranged 12-20 years with median age 15 years. Out of 182 stool samples examined 73 (40%) were found to be positive for parasites in which two or more parasites were found in 10 stool samples. Giardia lamblia 33 (18.1%) was the predominant parasite followed by hook worm 27 (14.8%) Entamoeba histolytica 13 (7.1%), Ascaris lumbricoides 05 (2.7%), Hyminolepis nana 02 (2.2%) and Trichuris trichiuria 01 (0.5%). Thirty-one (49.2%) in 63 females and 40 (33.6%) of the 119 males were positive for parasitic infections. The prevalence of worm infection was significantly higher in female children than male (p < or = 0.05). In contrast to the high parasitic prevalence rate in females they possessed significantly higher levels of awareness about parasitic infections. Out of 119 males 99 (83.2%) and 61 (96.8%) of the 63 females (p < or = 0.05) knew that worms suck food from host body. Similarly, 62.2% of males and 96.85 of females (p < or = 0.05) knew that parasites suck blood from human body. More study should be carried out to find out the gender difference in parasitic infection and level of exposure to risk factors.
Subject(s)
Adolescent , Adult , Awareness , Child , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Nepal/epidemiology , Parasitic Diseases/epidemiology , Prevalence , Sex FactorsABSTRACT
A total of 334 diarrheal fecal samples (from 210 males and 124 females) collected in Kathmandu, Nepal, were studied for various kinds of enteropathogens. Overall, 33% (111/334) fecal samples were positive for one or more enteropathogens. There was no difference in detection rates between males and females. Enteropathogen detection rates in summer, winter, spring, and autumn were 61% (40/66), 52% (45/87), 31% (25/81), and 25% (25/100), respectively. Altogether eight species of bacteria, three genera of viruses, and five species of protozoan parasites were detected with considerable seasonal variations. Among the bacterial isolates, enteropathogenic Escherichia coli topped the list followed by Vibrio sp. Only one sample had Shigella (S. sonnei). Rotavirus type A was the most frequently detected among the enteric viruses, followed by human enterovirus and human adenovirus, respectively. Among the enteric protozoan parasites, Giardia intestinalis was the most frequently detected followed by Cryptosporidium parvum. Detection of bacterial and protozoan pathogens showed a slightly high tendency in the summer season compared with that in the other seasons (p>0.05), whereas the detection of viruses was significantly high in the winter season (p<0.05). Of the total 57 water samples, 43 (75%) showed one or more bacterial species out of which 51% (22/43) were E. coli. Among the E. coli isolates, 68% were EPEC. Enterohemorrhagic E. coli (O157) was not detected.