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

Effect of artesunate on Toxoplasma gondii: in vitro and in vivo studies

The effect of Artesunate [As] on Toxoplasma gondii [T. gondii] in vitro and in vivo was studied. In vitro, tachyzoites of RH strain were exposed to As in a concentration of 2 microg/ml for 72 hours. The assessment of As effect was carried out by studying the viability, infectivity and ultrastructure changes of treated tachyzoites by scanning electron microscope [SEM]. In the in vivo study, Swiss albino mice were infected intraperitoneally with tachyzoites of T. gondii RH strain, then orally treated with As in a dose of 200 mg/kg for five successive days. The effect of As was evaluated by the mortality rate and survival time of the treated mice. Parasite burden, viability, infectivity and ultrastructure changes of tachyzoites harvested from the peritoneal cavities of infected treated mice as compared with infected non-treated control mice were also studied. In vitro study demonstrated a significant reduction in viability and infectivity of tachyzoites exposed to As compared with untreated controls. In vivo study, showed that treatment of infected mice with As induced a significant decrease in mortality rate and increase in survival time. There was also a significant reduction in parasite burden in infected treated mice with significant reduction in viability and infectivity of tachyzoites harvested from them as compared with infected non-treated control. SEM showed distortion in tachyzoites' shape, peeling, erosions and discontinuity in areas of surface membrane of treated tachyzoites of both in vitro and in vivo studies. So, As proved an effective and promising drug in treating acute toxoplasmosis

utility of direct agglutination [DAT] and fast agglutination screening [FAST] tests in serodiagnosis of experimental microsporidiosis

The present study was designed to evaluate the efficiency of two serodiagnostic tests; the direct agglutination test [DAT] and the fast agglutination screening test [FAST] in the diagnosis of Microsporidia in experimentally infected mice and to differentiate between different species of the parasite. The swiss albino mice were divided into non infected control and infected experimental groups which were further subdivided into ten subgroups. Ten samples of microsporidial spores were isolated from ten human stools and each one was used to infect each subgroup of mice. Stool and sera were collected weekly from each subgroup from the 1[st] to the 4[th] week post infection [PI]. DAT and FAST tests, using antigen prepared from the different species of microsporidial spores were used to detect antibodies in sera of different mice subgroups. The cross reactivity of microsporidial spores with the antibodies of Cyclospora cyatenensis and Cryptosporidium parvum was investigated by DAT and FAST. The results proved that DAT and FAST were effective in detecting microsporidial antibodies in sera of experimentally infected mice from the 2[nd] week PI till the end of the study, without cross reactivity with C. cyatenensis or C. parvum. They failed to differentiate between different Microspoiridia species used but, they gave good interpretation and they were specific and sensitive, and did not need sophisticated equipments

Impact of several control measures on the encysted metacercariae of heterophyids

The present study evaluated the effect of temperature, chemicals and microwave irradiation on the viability and infectivity of encysted metacercariae [EMC] of Pygidiopsis genata in fish. Flesh of infected fish was divided into two groups; control [GI] and experimental [GIl]. GII was subdivided into IIa: exposed to -4°C and -20°C for different periods, lIb: marinated in sodium chloride, acetic and citric acid at different concentrations and exposure times and IIe: subjected to microwave irradiation for 20 seconds. Assessment of the effect of these factors was by studying the viability and infectivity of EMC after isolation from the fish. The ultrastructure change was studied by scanning electron microscope [SEM], in comparison with control. The results showed that the highest significant reduction in the EMC viability and infectivity was detected in those exposed to microwave irradiation [100%]. SEM examination showed distortion in the shape of microwave-treated EMC with change in the surface nature. Freezing of EMC at -4°C and -20°C for 10 days at either temperature was sufficient to abolish their infectivity, although some were remained viable. Soaking of flesh in salt or acids reduced EMC viability and infectivity. So, microwave irradiation proved prophylactic for EMC

Validity of igG avidity enzyme linked immunosorbent assay and polymerase chain reaction for the determinatipn of toxoplasma infections during pregnancy

Accurate diagnosis of maternal toxoplasmosis can enhance the success of medical treatment and prevent congenital transmission. The current diagnostic methods have significant limits and they poorly differentiate between acute and chronic infections. The present study was conducted to diagnose acquired Toxoplasma infection in pregnant women by detecting both the low avidity-IgG using enzyme linked immunosorbent assay [ELISA] and the specific DNA by polymerase chain reaction technique [PCR]. The study was performed on 104 pregnant women at different gestational ages. The serum sample from each case was primarily screened for IgG by ELISA, and then positive samples were examined for IgM and estimation of IgG avidity ELISA. The PCR technique was performed on blood samples from twenty selected cases, ten of whom were positive for both IgG and IgM antibodies and the other ten were positive for IgG only. Out of 104 pregnant females screened by IgG ELISA 48 cases were positive. Twenty seven of these cases were positive for IgG only and 21 had both IgG and IgM antibodies. Of the 27 IgG positive cases 24 showed high IgG avidity while the remaining three showed inconclusive avidity. Of the 21 cases positive for both IgG and IgM antibodies 16 patients showed low avidity while five cases only showed high avidity. PCR was done for ten cases positive for both IgG and IgM antibodies and ten positive for IgG only. It proved positive in only four often cases who were positive for both IgG and IgM and had low IgG avidity. This study highlights the value of IgG avidity ELISA as a single serum sample test indicating the presence of infection and differentiating between acute and chronic infections. It is recommended as a routine test for every pregnant woman. A positive PCR can act as an excellent indicator of recent infection, but its disadvantage lies in the fact that negative results cannot exclude acute infection. In addition it is an expensive technique. Thus IgG avidity ELISA can be considered as a more appropriate technique

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

Influence of the antioxidant drug [antox] on experimental giardiasis and microsporidiosis

The effect of antioxidant [Antox] on Giardia lamblia and Microsporidium sp. in rats and mice respectively was studied. Pa-rasitologic effect was assessed by the mean parasitic count in infected animals' stool treated and non-treated, and infection intensity in stained section. Biochemical by measuring activities of lactate dehydrogenase [LDH], superoxide dismutase [SOD], malondialdehyde [MDA], myeloperoxidase [MPO] levels and cytokine induced neutrophil chemoattractant-1 [CINC-1] in intestinal homogenates in these animals as shown by cell injury, lipid peroxidation and neutrophil infiltrations. The present results showed that Antox significantly exacerbated G. lamblia and Microsporidium sp. This was manifested by a significant increase in number of G. lamblia cysts and trophozoites in stool and intestinal sections of treated infected rats. Also, microsporidian spores were significantly higher in stool of treated infected mice and infection intensity increased in the intestinal sections. The biochemical study showed a significantly higher degree of cell injury, lipid peroxidation and intestinal neutrophils accumulation in non-treated infected animals whether with G. lamblia or microsporidia. The changes reduced after treatment in giard-iasis but none in microsporidiosis. The results were tabulated photographed, and critically discussed

Congenital trichinellosis in experimentally infected mice

The present study aimed at allocating the time during pregnancy at which transpiacental transmission of Trichinella spiralis [T. spiralis] larvae took place. Swiss albino mice were infected at different durations of pregnancy; five days before mating, on gestation day zero and five days after mating. Furthermore, to study the effect of immunosuppression on transplacental transmission, half of the experimental mice were immunosuppressed using cyclophosphamide drug [Endoxan]. The percentage of infected uteri, embryos and placentas and the mean larval count were calculated on day 8 post infection [PT]. Moreover, the percentage of infected offspring and the mean larval count in their muscles were estimated on day 30 P1. The results of the present study revealed that, transpiacental transmission of T. spiralis could occur in offspring of mice when their mothers are infected before or after pregnancy. This was documented by the presence of larvae in the muscles of offspring. However, the rate of this transmission increased when the mothers are infected at late pregnancy whether they were immunosuppressed or not. The administration of the immunosuppressive drug whether before or after pregnancy increased the rate of infection and the mean larval count in both uteri of mothers and muscles of their offspring. A higher percentage of abortion was demonstrated in females infected before mating in different studied groups

utility of lactoferrin in differentiating parasitic from bacterial infections

Lactoferrin is an iron binding glycoprotein found in the 2 ry granules of PMN. In order to determine the usefulness of such marker for neutrophilic activity in differentiating cases suffering from amoebic and bacillary dysentery, Schistosoma and bacterial UTI infections, we examined stool and urine specimens using anti-lactoferrin antibodies [lactoferrin latex agglutination test: LFLA], compared with different standard gold techniques. Our results demonstrated that cases with either shigllosis or UTI revealed a high lactoferrin titer which was positively correlated with the number of PMN. In addition cases with Entamoeba histolytica or S. haematobium were characterized by relatively lower inflammatory process as expressed by mild lactoferrin titer which was also correlated with the PMN count. In addition, the findings of the present work indicated that LFLA was sensitive and specific when used alone and its sensitivity was augmented after coupling with other simple indirect methods of diagnosis. In conclusion, results described the reliability of using LFLA as a simple, rapid, sensitive method in differentiating, certain parasitic from bacterial diseases

effect of potassium permanganate and sodium dichloroisocyanurate on metacercariae of fasciola gigantica

Batches of encysted metacercariae of F. Gigantica adhered to transparent polyethylene sheets were treated with KMnO4, while others were treated with NaDCC at specific concentrations and exposure times. An assessment of their effects was carried out by the detached percentage and viable metacercariae and scanning electron microscope [SEM] ultrastructural changes. In addition, their effects on the leaves of green vegetables were reported. The results showed that all metacercariae were detached and died due to their exposure to KMnO4 [96%] and NaDCC [100%] were detached from the polyethylene sheets. SEM showed that the deformities in the metacercariae soaked in NaDCC were more severe than those dipped in KMnO4. However, neither KMnO4 nor NaDCC affected the consistency, color taste or flavor of the vegetable leaves. The two disinfectants, particularly NaDCC, proved to be safe, effective against the encysted metacercariae with no side effects

Vaccination against congenital toxoplasmosis

Different types of Toxoplasma gondii vaccines were evaluated using parasitological and histopathological means to induce immunity in Swiss pregnant mice and their pups against the challenge with virulent RH strain. Immunization was performed before mating by using live cyst vaccines [LCV], LCV-IL-2 combination, irradiated cyst vaccine [ICV] and ICV-IL-2 combination. It was demonstrated that pre- immunization with the current vaccines offered a significant protection of both dams and pups. The highest level of protection was noticed in mice received LCV-IL2, followed by ICV-IL-2, then LCV and the least protection was elicited in dams immunized with ICV alone. The results revealed the possibility of applying such accines, not only in mice but also in other mammalian hosts including humans

Bacterial-parasite interaction between salmonella and each of fasciola gigantica and trichinella spiralis

The possibility of bacterial-parasite interaction between Salmonella typhimurium and the surface of each of Fasciola gigantica metacercariae and Trichinella spiralis larvae was investigated in vitro. Two studies were carried out. In the first, S. Typhimurium were incubated in vitro with the metacercariae of F. Gigantica. In the second, S. typhimurium was incubated with larvae of T. Spiralis. The interactions of S. typhimurium with each of F. Gigantica metacercariae and T. spiralis larvae were studied by scanning electron microscope [SEM]. In the first study, numerous bacilli were found adhered to the metacercariae surface. In the second study, no S. typhimurium was observed on the wall of T. Spiralis larvae. The results indicated that only F. Gigantica metacercariae act as a carrier for S. typhimurium with the possibility of occurrence of mixed infections with both organisms. So, both fascioliasis and salmonellosis must be treated concomitantly

study on patients with eosinophilia of suspected parasitic origin

A study of 53 patients with eosinophilia of suspected parasitic origin was conducted. Investigations done for each case included stool and urine examinations, absolute eosinophilic count and countercurrent immunoelectrophoresis [CIEP] using crude antigens of Fasciola hepatica, Schistosoma mansoni worms, Trichinella spiralis and Toxocara canis larvae and hydatid. Stool examination revealed 6 cases with Fasciola eggs, 2 with Ascaris lumbricoides and 1 with S. mansoni eggs. The eosinophilic count ranged from 682 to 10560 cell/mm3. 26 cases showed mild eosinophilia, 24 moderate and 3 marked eosinophilia. Out of the 53 cases examined by the CIEP, 30 were positive with Fasciola antigen. Their eosinophilic count ranged from 770 to 10560 cell/mm3. 6 cases were positive with hydatid antigen and had an eosinophilic count ranging from 825 to 2970 cell/mm3. Only one case was positive with S. mansoni antigen and its eosinophilic count was 935 cell/mm3. 16 cases were negative with the different antigens used and their eosinophilic count ranged from 682 to 2200 cell/mm3