Disinfection efficacy of sodium dichloroisocyanurate [NaDCC] against common food-borne intestinal protozoa

The present study was conducted to investigate the efficacy of sodium dich-loroisocyanurate [NaDCC] on the infective stages of common food-borne intestinal protozoa; Entamoeba histolytica [E. histolytica], Giardia lamblia [G. lamblia], Cryptosporidium, Cyclospora and Microsporidia; beside its effect on raw green vegetables and fruits. Parasites, isolated from stool of patients with diarrhea or dysentery, were exposed to NaDCC solution [1g/l] for one and two hours. Disinfection effect of NaDCC was assessed by in-vitro viability, using trypan blue stain, and infectivity bioassay in laboratory animals as indicated by fecal and intestinal parasitic counts. Raw vegetables and fruits were dipped in NaDCC solution in the same concentration and exposure time as used for treatment of the parasites. Results revealed statistically significant reductions in viability and infectivity of all examined parasites indicating their susceptibility to NaDCC. Relative variations in susceptibility were revealed; E. histolytica and G. lamblia were most susceptible [100% reduction] followed by Microsporidia then Cryptospridium and Cyclospora. NaDCC did not affect the consistency, color, taste or flavor of raw green vegetables and fruits. The proved efficacy of NaDCC, in cheap and convenient dry tablet form, makes it a promising tool in decontaminating raw vegetables and fruits from food-borne protozoan parasites at household and restaurant levels as well as in catering and fresh produce industry. It is also recommended for disinfection of food preparation surfaces and equipment

Immunization against trichinellosis using microwaved larvae of trichinela spiralis

The present study evaluated the effect of microwave irradiation on infective larvae of Trichinella spiralis [T. spiralis] by the ultrastructure changes of the microwaved larvae [ML] using scanning electron microscope [SEM]. The ML tested the ability to immunize mice against a challenge infection with T. spiralis. For the optimal dose and the best route of immunization inducing protection against challenge infection, two doses were used; 300 and 600 ML as one or two-dose regimen, each dose was given orally and intraperitoneally [IP]. SEM revealed tegumenttal damage of the ML in the form of distortion, loss of normal fold pattern and depressions or papillae protruded from their outer surface. After administration of the ML [orally or IP] to the non-infected control mice, neither adults nor larvae were detected in the intestines or muscles respectively. This indicated loss of larvae infectivity after exposure to the microwave irradiation. Also, a significant protection against challenge infection with T. spiralis was demonstrated in experimental mice immunized by ML, orally or IP. This was assessed by a statistically significant decrease in adult and muscle larval count, compared with the non-immunized infected control. Complete protection against both adults and larvae [100%] was achieved by IP injection of two doses of 600 ML, two weeks apart. The results suggested the feasible application of the microwave irradiation on meat for its decontamination from T. spiralis larvae. Such a method might be a promising a prophylaxis vaccine against trichinellosis in animals and/or humans

efficacy of antihelminthic compound; clorsulon against experimental schistosoma mansoni infection

The efficacy of Clorsulon[R] [CLS] against experimental schis-tosomiasis mansoni, using Praziquantel[R] [PZQ] as a therapeutic control was evaluated. Swiss Albino mice were divided into infected non-treated control, PZQ-treated group given a single dose of 500 mg/kg four weeks post infection [PI], and infected mice treated with single, double, and triple doses of 5 mg/kg CLS per dose, one week apart starting from the 4[th] week PI. All animals were perfused for adults count. Parts of livers and intestines were examined for granulomata number and sizes. Pathological changes in hepatic parenchyma by H and E and Masson trichrome stains were also examined. Results revealed that a single treatment with PZQ caused a significant percentage reducetion [%R] of worm load [92.68%], mean egg count in liver and intestine [91.20 and 94.01% respectively], and mean size of liver granulomata was reduced [92.06%]. Regarding CLS, the worm burden was reduced proportionally with number of doses given; 87.80, 96.34 and 97.56% in single, double and triple exposures successively. Egg count in liver was decreased by 85.90, 97.01 and 96.23% respectively in treated mice. Number of intestinal granulomata was decreased by 85.28, 94.24 and 95.49% in a similar way. Size of hepatic granulomata was decreased by 89.02, 94.51 and 95.05% by 1, 2 and 3 doses consecutively. All parameters reflected non significant difference between 2 and 3 dose of CLS. The results were critically discussed

rapid technique for diagnosis of intestinal parasitic infection

This study was carried out on stool specimens of 150 cases attending the outpatient clinics of the Faculty of Medicine, Alexandria University. All patients were suffering from gastro-intestinal disturbance specially diarrhoea. Each specimen was examined for intestinal parasites by direct saline and iodine smears and was stained by using: quantitative buffy coat [QBC] tube technique, modified trichrome and modified Ziehl Neelsen stains. This work aimed to evaluate the quantitative buffy coat tube method in diagnosis of parasitic infection in such cases, comparing it with the other staining reference techniques used simultaneously. Out of 150 diarrhaeic patients 67 were positive for protozoa. These protozoa identified in the examined specimens were Giardia lamblia, Cryptosporidium parvum, Cyclospora, Microsporidia and Blastocystis hominis. The results showed high sensitivity and specificity [100%] of the QBC tube method over the other staining techniques