Evaluation of flow cytometry as a diagnostic method for detection of Giardia lambila in comparison to IFAT and other conventional staining techniques in fecal samples

Giardia lamblia is one of the most common diarrhea-related parasites in humans, where infection ranges from asymptomatic to acute or chronic disease. Because of the non-characteristic symptoms of giardiasis, as well as significant prevalence of cyst carriers, it is necessary to upgrade parasitological techniques for examination of feces, in order to avoid false negative results. Accurate diagnosis is important to exclude other parasitic causes of diarrhea. The present study is designed to assess the efficacy of flow cytometry [FC] as a sensitive method for detection of G. lamblia cysts in stool samples in comparison with other standard conventional diagnostic methods. 70 patients [30 males and 40 females] ranging in age from 5 to 60 years were included in this study. Stool samples were taken from each patient on three successive days to detect Giardia cysts and evaluate the intensity of infection. Different methods were used that included concentration methods, permanent stained slides, immunofluorescent antibody test [IFAT] and FC. Giardia lamblia cysts were detected in 24 samples by IFAT with detection rate of 34.3%. Using trichrome stain 20 samples [28.6%] were positive, modified Ziehl- Neelsen Stain [MZN] detected 11samples [15.7%], while Acridine Orange [AO] detected 14 positive samples [20%]. Flow cytometry detected 18 samples with detection rate of 25.7%. Sensitivity and specificity of FC were 90% and 100%, respectively and IFAT sensitivity and specificity were100% and 92%, respectively. Results of the present study clearly demonstrated that incorporation of IFAT and FC can improve sensitivity of detection of Giardia cysts in stool samples. Although FC is more expensive than the other staining methods and IFAT, it is rapid, simple and accurate in estimating the quantity of parasites in each sample. Thus, FC can be recommended for detection of protozoa in stool

Protective role of Spirulina feed in a freshwater fish (Poecilia reticulata Peters) exposed to an azo dye-methyl red.

Acute toxicity of an azo dye-methyl red (5-40 ppm) was examined under starving conditions, on two groups of Poecilia reticulata--a freshwater fish, fed on different diets prior to their exposure to dye. Besides natural feed, fish of group-1 also received Spirulina feed for one month (feed population), whereas those of group-2 received only natural feed (non-feed population). The mortality data revealed non-feed population to be more tolerant to feed stress during acute toxicity study, whereas feed population exhibited better tolerance to the combined stress of both feed and methyl red; especially at higher concentrations of the latter. RBCs in methyl red treatments acquired different shapes (poikilocytosis) and an increase in their size (anisocytosis) was also noticed. Percentage of such abnormal RBCs was almost equal in both feed and non-feed populations, except at a lower concentration (5 ppm), at which percentage of poikilocytic RBCs was lesser in the feed population. RBC counts in the control non-feed fish (34.5 x 10(4)/mm3) were significantly lower than control feed population (50.0 x 10(4) /mm3). Their number decreased with an increase in methyl red concentrations in non-feed population (9-26%), but percent reduction in RBC counts was almost similar (20-26%) at various concentrations of methyl red (5-30 ppm) in the feed population. Despite reduction in RBC counts, feed population did not suffer from anemia in methyl red treatments, as evident by their RBC counts which were almost equal to control fish of non-feed population. The results suggest that Spirulina feed improves tolerance of test organism towards methyl red manifested by noticeable reduction in the cytotoxic effects on RBCs and a lower mortality rate at higher concentrations of dye.

Occupational Asthma Due to Azodicarbonamide

Azodicarbonamide is a low molecular weight foaming agent for plastics and rubbers. Azodicarbonamide can elicit acute and chronic health related problems due to its potential for pulmonary and cutaneous sensitization. Some cases of occupational asthma associated with exposure to azodicarbonamide have been reported, of which only a few cases were confirmed by specific inhalation challenges. Here, the first case of occupational asthma due to azodicarbonamide in Korea, in which the diagnosis was confirmed by specific inhalation challenge, is reported.