Giardia duodenalis pathogenicity on immunosuppressed animal model

Giardiasis is the major water-borne diarrheal disease present worldwide caused by the common intestinal parasite, Giardia duodenalis. This work aims to investigate the effect of G. duodenalis infection pathogenicity in immunosuppressed animals through histopathological examination. A total of 45 BALB/c mice were divided into four groups; G1 (negative control), G2 (healthy animals exposed to Giardia); G3 (immunosuppressed animals exposed to Giardia), and G4 (non-exposed immunosuppressed animals). Our study revealed that G3 was the most affected group with an infection rate of 100%. The animals showed general weakness, soft stool, and high death rate with severe histopathological changes in the duodenum and mild degenerative changes in hepatic tissues. In G2, the maximal lesions in both duodenum and liver were on the 11^th day. We spotted damage in the villi, edema in the central core, and submucosa, in addition to increased cellular infiltration with inflammation in lamina propria. The presence of the parasites within the villi and the lumen was clear. Most of the hepatocytes revealed hydropic and fatty changes, also dilated congested central veins and edema were observed. G3 changes were more intense than G2 with massive Giardia trophozoites between the intestinal villi, lumen, and extensive fatty liver degeneration. Immune suppression plays a significant role in the severity of injury with the Giardia parasites in duodenum and liver cells.

Detection of Giardia lamblia by Microscopic Examination, Rapid Chromatographic Immunoassay Test, and Molecular Technique

Background

Giardia lamblia is a pathogenic intestinal flagellate transmitted by the ingestion of contaminated water or food with the cyst stage of the parasite. Giardiasis can cause severe acute diarrhea and malabsorption or may persist as a chronic infection. Effective treatment and control measures depend on proper laboratory diagnosis using diagnostic methods with high sensitivity and specificity.

Objective

To compare the sensitivity and specificity of direct smear, Ritchie sedimentation technique, two brands of rapid chromatographic immunoassay test, and real-time polymerase chain reaction (PCR) for the detection of G. lamblia in clinical human fecal samples.

Materials and methods

Unpreserved 100 stool specimens were collected in clean plastic containers and labeled with the patient’s information and examined through light microscopy, immunochromatographic test (ICTs), and real-time PCR.

Results

Out of 100 fresh stool samples obtained from workers analyzed, real-time PCR targeting the SSU rRNA gene was able to detect Giardia deoxyribonucleic acid (DNA) in (42) samples followed by ImmunoCard STAT! (31) samples (Meridian Bioscience, Germany), direct smear (23) samples, CerTest (19) samples (Biotec, Zaragoza, Spain), and Ritchie technique (17) samples. Real-time PCR was the most sensitive for the diagnosis of G. lamblia in comparison to the other techniques.

Conclusions

All the techniques investigated were sensitive for the detection of G. lamblia in stool samples. Further studies are recommended using multiplex real-time PCR assay in order to increase the possibility of the presence or absence of the infection.

Therapeutic effects of Schistosoma mansoni soluble egg antigen in high fat diet induced dyslipidemia, hepatic and cardiovascular pathology in mice

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.

Prevalence of hydatidosis among slaughtered animals in Jeddah, Kingdom of Saudi Arabia

This study was conducted over one year in the major North Jeddah abattoir to assess the current status of hydatidosis among slaughtered animals. The cysts count size, site of infection and fertility were conducted on randomly infected animals. A total of (91348) slaughtered animals; camels (541), cattle (615), goats (48370) and sheep (41822) were macroscopically and microscopically examined. The infection prevalence was 6.86%, 3.63%, 69.6% & 19.85% in camels, cattle, sheep and goats respectively. The liver was the predominant site of infection in all animals. The intensity of cysts differed significantly among all host species. Most of cysts were small in size and was found more in the liver than in the lung. There was a significant difference among host species in fertile cysts (P < 0.00). The higher percentage of fertile cysts was in goat (9.87%) and sheep (4.85%). The viability rate of protoscolces was significantly different in all examined animals with a higher rate among sheep and goats. These findings reflect the existence of the life cycle maintenance and the transmission of the cestode Echinococcus granulosus from definitive host (dogs) to intermediate hosts (camels, cattle, sheep and goats) in Jeddah.

Effect of immunosuppression on the course of cryptosporidiosis experimentally

This study evaluated the effect of immunosuppression on experimental cryptosporidiosis, by parasitological and histopathological studies at different days post infection (p.i). A total of one hundred five clean laboratory bred male Wister rats were divided into four groups: normal control group (GI), infected group (GII), immunosuppressed control group (GIII) and immunosuppressed infected group (GIV). The infection was done by inoculation orally with 10(5) Cryptosporidium oocysts in 0.1 ml PBS. The immunosuppression was done by administration of cytotoxic drug (Endoxan) intraperitoneal in a dose of 5 mg/kg/d for 4 weeks. The results showed that in GII, most of animals attained its activities without apparent clinical symptoms except some of them had diarrhea while in GIV, all had diarrhea, loss of appetite, weakness, lethargy and hair loss. The death rate was (10%) in GII while in GIV was 51.4%. The infection rate among GII was 95% and GIV was 100%. The infection intensity was higher in GIV than in GIII and the greatest number of excreted oocysts was observed on day 15th post-infection (PI) in GIV and on day 11th PI in GII. The histopathological changes in the ileum were more advanced in GIV.

The efficacy of Origanum vulgare on Eimeria tenella

Eimeria tenella is one of the most common and pathogenic species of the genus Eimeria in the chicken and is associated with many coccidiosis outbreaks and a high rate of mortality. Experimentally, Origanum vulgare proved to be an anti-Eimeria tenella regimen.

Toxoplasma gondii: Ultrastructure study of the entry of tachyzoites into mammalian cells

Toxoplama gondii (Apicomplexa: Coccidia), an obligatory intracellular parasite with a unique capacity to invade virtually all nucleated cell type from warm-blooded vertebrate hosts. Despite the efficiency with which Toxoplasma enters its host cell, it remains unresolved if invasion occurs by direct penetration of the parasite or through phagocytosis. In the present work, electron microscopic study was designed to examine the entry process of Toxoplasma (RH strain) into macrophages and non phagocytic-host cells (Hela cells) and to observe the ultrastructure changes associated with intracellular parasitism. The results showed that both active invasion and phagocytosis were occurred and revealed that invasion is an ordered process that initiates with binding of the parasite at its apical end followed by tight-fitting invagination of the host cell membrane and a prominent constriction in the parasite at the site of penetration. The process ended by the professional parasitophorous vacuole that is distinct at the outset from those formed by phagocytosis in which once Toxoplasma triggered, phagocytic uptake can proceed by capture of the parasite within a loose fitting vacuole formed by localized membrane ruffling. The cytopathic effects of the parasite on macrophages and Hela cells were demonstrated within 5-15 h post-inoculation in the form of degenerative mitochondria, swelling Golgi apparatus and widening of endoplasmic reticulum indicating intracellular oedema. These changes were exaggerated and several cells were found dead after 48-72 h.

Effect of treatment with Neem (Azadirachta indica) compared with Baycox drug on the caecum of chicken experimentally infected with Eimeria tenella

The study evaluated the therapeutic efficacy of Neem herb in chicken experimentally infected with E. tenella compared to Baycox as a reference anticoccidial drug. 120 broiler chicks were enrolled, randomly divided to 4 groups, (A, B, C & D) non-infected non-treated (naïve control), (B) infected with 10(4) E. tenella oocysts (infected control), (C) infected and treated with Baycox (7 mg/kg b.w. for 2 days) and (D) infected and treated with Neem leaves water extract (100 mg/kg b.w. for 9 days). Evaluation was by clinical signs, performance data (gain weigh, food consumption oocyst shed/gram feaces (OPG)), in addition to histopathological changes in all chickens. The results revealed that chicks of GA had the best performance data compared to GB, GC & GD. In GC & GD there were a remarkable improvement in the data performance, clinical signs, gross and microscopically cecal lesions compared to GB. The efficacy of Baycox (GC) was shown to be superior to that of Neem (GD) compared to GB but an additive histopathological toxic effect besides those produced by E. tenella infection could be recorded. In contrast, Neem appeared to have a remarkable improvement on cecal integrity.

Efficacy of garlic extract on hepatic coccidiosis in infected rabbits (Oryctolagus cuniculus): histological and biochemical studies

The rabbits were divided into three groups, of 12 rabbits each. G1 was the (non-infected non-treated) as control, G2 was the (infected-non treated), and G3 was the (infected and treated) rabbits. Each rabbit in the infected groups were given (10(3)) sporuleted oocysts of Eimeria stiedae per rabbit after forty five days exactly. Faecal sample of rabbits from each group were examined each day post infection till oocysts appeared in faeces. The treatment was given by using suitable dosage of garlic according to body weight. After 15, 21, 28, & 35 days post-treatment faecal oocysts were output. Biochemical parameters as serum liver function (ALT, AST, GGT & ALP) that denoted the he-patic cells injury. The results showed a significant differences in the mean values of oocysts shedding and their mean number in bile ducts between Gs 2 &3 from the 15th day post infection (PI) (mean +/-SD:40.33 +/- 16.72 & 25.17 +/- .56 respectively) till the experimental end on the 35th day (55.75 +/- 19.79 & 0.94 +/- 1.43 respectively). The histopathological alterations were in liver of G2 at the experimental end. Coccidiosis in G2 induced histopathological alterations in liver tissue, marked cytoplasmic vacuolations in hepatocytes with clear signs of karyolysis, and dilatation of sinusoids with increase in Kupffer cells. Leukocytic infiltration around congested blood vessels was noticed. Efficacy of garlic on E. stiedae in infected Gs was resident. The liver of G3 regained almost normal appearance compared to control.

Effect of aflatoxin on the coccidial infection in broilers

Two hundred of one day old chickens were divided into four equal groups and kept for the end of experiment. The first group was kept as control negative, the second group received 1 ppm of dietary aflatoxin from day zero of chick life till the end of present study, while the third group was given 4x104 sporulated oocysts of Eimeria sp., the group four were obtained coccidial oocysts and aflatoxin in their rations. The combination of aflatoxin and coccidia, produced higher mortality rate, higher faecal scores and increased oocysts output than those chicks received aflatoxin or coccidia only. Body weighs and efficiency of feed utilization were decreased in all treated groups. The maximal losses of body weight and efficiency of feed utilization were noticed in chicks infected with Eimeria sp. and at received aflatoxin in their ration. The levels of total serum proteins, gamma globulins, calcium and phosphorus were decreased in chicks infected with coccidia and received dietary aflatoxin. Total bilirubin and SGOT activity were higher in chicks infected with Eimeria sp, and obtained aflatoxin.