A factor derived from adult rat and cow small intestine reduces Cryptosporidium parvum infection in infant rats

Cryptosporidium parvum is an intracellular protozoan parasite of the mammalian intestine. In rats, C. parvum infection is age related; infants are susceptible, whereas adults are resistant. The transition from susceptibility to resistance usually takes place around the age of weaning. In the present study, infant rats were orally inoculated with a preparation of intestinal scrapings taken from adult rats or cows. Infant rats received the scrapings daily from 3 to 14 days of age, were inoculated with C. parvum oocysts at 9 days of age, and killed at 15 days of age. Fecal samples and intestinal tissues were examined for the presence of C. parvum. Significantly fewer rats were infected in the groups that received intestinal scrapings compared with controls. In addition, infected rats in the treatment groups shed significantly fewer oocysts than those in the control group. Scrapings from the intestinal mucosa of adult cows were also able to protect infant rats from infection, whereas scrapings from intestines of calves were not protective. In sum, these data indicate the presence of a factor in the intestines of adult rats and cows that can transfer protection against C. parvum infection to susceptible infant rats.     

Variation of mucin distribution in the rat intestine, caecum and colon: effect of the bacterial flora.

The influence of the intestinal microflora on mucin types was studied in the small intestine, caecum and colon of conventional (CV) rats as compared to germ-free (GF) rats. A colorimetric method was used on purified water-soluble mucin extracted from mucosal scrapings and contents. Variations occurred between the three anatomical sites both in the mucosas and intestinal contents of GF rats. In CV rats, the presence of the bacterial flora led to different effects depending on the intestinal site: in the small intestinal mucosa, neutral and sulphomucins values were higher whereas sialomucin was much lower. Conversely, sialomucin was higher in the caecal and colonic mucosas and contents whereas sulphated mucins were decreased significantly in caecal contents and caecal and colonic mucosas. These variations in the contents may reflect the bacterial mucolytic activity and the effect of bacterial metabolites on the mucosa.     

Prevalence and identity of coccidia in pen-raised wild turkeys

One hundred nineteen pen-raised wild turkeys (Meleagris gallopavo) from 12 locations in nine states in the United States were examined for coccidia by sugar flotation of intestinal contents and mucosa or by subinoculating the contents into uninfected domestic turkeys. Seventy-eight (66%) of the turkeys were positive for coccidia. There were no differences in the frequency of coccidia among adult, sub-adult or juvenile turkeys. More females (75%) were infected than males (48%). The species of coccidia from 30 of the turkeys were identified based on microscopic examination of oocysts, fresh scrapings, stained sections and inoculations of bobwhites (Colinus virginianus). The frequency of each species was Eimeria meleagrimitis (97%), E. gallopavonis (47%), E. meleagridis (27%), E. dispersa (17%), E. innocua-E. subrotunda (13%), E. adenoeides (7%) and an undescribed species (3%). Of the 30 turkeys in which the species of coccidia was determined, 30% had a single species infection, 40% had two species, 20% had three species and 10% had four species.     

Intestinal parasitic infections in pre-school children in the Niger Delta

Stool specimens from 1,062 pre-school children in the Niger Delta were examined for the presence of intestinal parasites. Of that number, 77.6% harboured one or more than one species of intestinal parasites. Ascaris lumbricoides (51.9%) and Trichuris trichiura (41.7%) were the most prevalent species recorded. Other parasites harboured by these children included Hymenolepis sp. (18.3%), Giardia lamblia (9.2%), Entamoeba histolytica (4.6%), Strongyloides stercoralis (1.4%). Hookworm, Taenia sp., Isospora sp. and Trichostrongylus sp. occurred in less than 1% of the children examined. These high rates of infection are associated with poor sanitary conditions prevalent in the area. Improvement of environmental sanitation is advised to reduce human sufferings caused by parasites in that area particularly among children.     

Strongyloides ratti: Mast cell and goblet cell responses in the small intestine of infected rats

Kinetics of intestinal mast cells and goblet cells were examined in relation to worm localization at various sites in the small intestine of rats infected with 3000 filariform (stage 3) larvae of Strongyloides ratti. The most marked intestinal mastocytosis was observed on Day 20 at the anterior site of the small intestine where the majority of the worms had concentrated. The number of mast cells in the posterior small intestine increased in parallel with the posterior shift of parasites at the later stage of the infection. In contrast to the intestinal mast cell response, the number of goblet cells was not significantly affected by the infection. These results strongly suggest that intestinal mastocytosis is closely related to the presence of the worms and that mast cells may play an important role for the expulsion of S. ratti.     

Risk of contamination of human and agricultural environment with parasites through reuse of treated municipal wastewater in Riyadh, Saudi Arabia.

Two selected sites in the Riyadh metropolitan area were surveyed for the presence of human pathogenic parasites in treated municipal wastewater (TMWW). A total of 100 samples were collected from both sites at two different seasons, the winter and summer reason. The most common parasites seen were the larvae and adult of Strongyloides sp. There were few Ascaris lumbricoides ova, some of which were embryonated and possibly infective, while the highest frequency of Ascaris ova (100 +/litre) was found at site 2 h, the highest frequency of Strongyloides sp. larvae (36-72/litre) and Strongyloides sp. adult (100 +/litre) were found at sites 2 W and 1 W respectively. The variation between sites and seasonal fluctuations showed a significant difference in parasite per litre. High atmospheric temperatures in the Riyadh area seem to be lethal to most intestinal pathogens similarly the absence of protozoal cysts in the TMWW could be attributed to certain treatment processes and other environmental factors. Data obtained from this study will be valuable in planning for the control of parasitic diseases in particular and public health pathogens in general.     

A survey of gastrointestinal parasites of olive baboons (Papio anubis) in human settlement areas of Mole National Park, Ghana

Fecal samples from 55 free-ranging olive baboons (Papio anubis) in Mole National Park, Ghana, were collected 22 June-7 July 2008 and analyzed for gastrointestinal parasites. This is the first survey of baboon gastrointestinal parasites in Ghana and provides baseline data for this area. Ninety-three percent of samples were infected, leaving 7% with no parasites observed. Of those infected, there was a 76% prevalence of strongyles, 53% Strongyloides spp., 11% Abbreviata caucasica , 62% prevalence of Balantidium coli (trophozoites and cysts identified), 4% Entomeba hystolytica/dispar, and 47% unidentified protozoan parasites. Of the strongyle infections, 9% were identified as Oesophagostamum sp. One sample contained an unidentified spirurid nematode that resembled Gongylonema sp. Mole has a mixed forest-savanna habitat, and baboons frequently range into human areas, which makes them subject to parasites from each habitat and multiple sources of exposure. We found a high prevalence of nematode parasites, consistent with a wet or cooler forest environment, or high rates of fecal contamination. The presence of Strongyloides sp., E. hystolitica/dispar, and B. coli suggest potential public health risk from baboons, but molecular identification of these parasites, and documentation of their presence in local human populations, would be necessary to confirm zoonotic transmission.     

Selective medium for Corynebacterium kutscheri and localization of the organism in mice and rats

A new selective medium for isolation of Corynebacterium kutscheri (CK) from animals suffering subclinical infection was made by adding furazolidone, nalidixic acid and corimycin to the heart infusion agar base, this being named FNC agar. The FNC agar inhibited the growth of gram-negative rods, Pseudomonas aeruginosa, Proteus sp. and gram-positive cocci but did not affect the growth of CK. When this medium was used to isolate CK from the oral cavity and cecal contents of mice and rats, two of 6 conventional mouse colonies and three of 8 conventional rat colonies were found to be infected, with isolation of the organism from 19 mice and 12 rats in total. The animals showed neither clinical signs nor lesions, but the antibody was positive in 11 mice and 10 rats. In mice and rats inoculated orally with 4 x 10(8) and 1 x 10(9) organisms, respectively, CK was isolated for 20 weeks post-inoculation by use FNC agar. The isolation rate of the organism was the highest in the oral cavities of both inoculated mice and rats, and also in the submaxillary lymph nodes of the inoculated rats. The organism was also recovered from the cecal contents of more than half of the inoculated mice and rats. Thus, it was considered that FNC agar was useful in isolating CK from the oral cavity and cecal contents of mice and rats with subclinical infection of the organism.     

Influence of habitat modification on the community of gastrointestinal helminths of cotton rats.

Dynamics of communities of gastrointestinal helminths of cotton rats (Sigmodon hispidus) were monitored in response to five experimental brush management treatments using herbicide applications with and without prescribed burning on the Cross Timbers Experimental Range in Payne County, Oklahoma (USA). A total of 113 adult cotton rats (68 male and 45 female) was collected from experimental pastures in winter and summer 1986 resulting in the recovery of five species of helminths: Longistriata adunca, Syphacia sigmodontis, Strongyloides sp., Protospirura muris, and Raillietina sp. Prevalences of Raillietina sp. and S. sigmodontis were greater on control than herbicide-treated pastures. Prevalence and abundance of Raillietina sp. and prevalence of S. sigmodontis were significantly lower on annually burned, herbicide-treated pastures compared to unburned herbicide-treated pastures. Triclopyr-treated pastures had greater abundances of L. adunca and lower abundances of Raillietina sp. than those treated with tebuthiuron. Abundances of L. adunca also decreased from winter to summer on annually burned, herbicide-treated pastures while increasing on other pastures. Distribution of all helminths was overdispersed, but distribution of L. adunca showed a significant brush treatment by season interaction as a result of greater overdispersion in summer than winter for cotton rats inhabiting brush-treated pastures. Our results indicate that man-induced habitat modifications can alter host-parasite relationships in the community.     

Cholangiohepatitis and inflammatory bowel disease induced by a novel urease-negative Helicobacter species in A/J and Tac:ICR:HascidfRF mice

Helicobacter bilis and H. hepaticus, both urease-positive intestinal helicobacters of mice, have been shown experimentally to induce proliferative typhlocolitis in scid mice. We recently isolated a urease-negative Helicobacter sp. (H. sp.) that also induced proliferative typhlocolitis in pilot studies in scid mice. To determine the pathogenic potential of H. sp. in immunocompromised and immunocompetent mice, 5-week old male A/J or Tac:Icr:Ha(ICR)-scidfRF mice were inoculated by intraperitoneal (IP) injection with approximately 3 x 10(7) colony-forming units (CFU) of H. sp. Mice were necropsied at various time points postinoculation (PI). Sham-inoculated mice had no clinical, gross, or histopathological lesions. In contrast, scid mice inoculated IP with H. sp. had severe hemorrhagic diarrhea and decreased weight gain at 2, 7, and 18 weeks postinoculation (PI), with severe proliferative typhlocolitis, phlebothrombosis, and hepatitis. A/J mice had no clinical signs, but had mild to moderate proliferative typhlocolitis and moderate to marked cholangiohepatitis at 7 and 24 weeks PI. A/J mice infected with H. sp. developed robust immune responses of a predominant Th1 type. This report demonstrates that infection with a urease-negative helicobacter can cause inflammatory bowel disease (IBD) and hepatitis in scid and immunocompetent A/J mice. These results provide a new model of IBD and cholangio-hepatitis associated with a specific urease-negative, novel H. species.     

A synthetic analog of prostaglandin E(1) prevents the production of reactive oxygen species in the intestinal mucosa of methotrexate-treated rats

Administration of methotrexate to rats results in severe enterocolitis and death. Previous our studies showed that a synthetic analog of prostaglandin E(1), OP-1206 [17S, 20-dimethyl-trans-Delta(2)-prostaglandin E(1)] ameliorated the anticancer agent-induced enterocolitis of rats. In the current study, we have focused on the biochemical effect of OP-1206 on the methotrexate-induced intestinal inflammation implicating reactive oxygen species (ROS). Methotrexate (15 mg/kg body weight) was orally administered to rats once daily for 5 days. OP-1206 (0.5 microg/kg body weight) was orally administered to rats twice a day for 5 days. On the 6th day, the chemiluminescence from the jejunum was measured to evaluate the generation of ROS. Spontaneous chemiluminescence from the jejunum of the methotrexate-treated rats increased significantly, compared with the control. Luminol-enhanced chemiluminescence from inflamed mucosal scrapings from the jejunum of the methotrexate-treated rats indicated more remarkable enhancement than the control rats. The treatment of OP-1206 with methotrexate showed significantly lower chemiluminescence of both the jejunum and mucosal scrapings than those of the methotrexate-treated rats. The alkaline phosphatase (ALP) activity, as a marker of small intestinal differentiation, in the intestinal mucosa of the methotrexate-treated rats decreased remarkably, but that of the methotrexate and OP-1206-treated rats was significantly higher than that of the methotrexate-treated rats. Thus, OP-1206 may possibly help the anticancer chemotherapy by protecting the small intestine from the methotrexate-induced damage.     

Effect of enteric micro-organisms on intestinal sugar and fatty acid absorption

The effect of micro-organisms contaminating the upper intestinal contents of malnourished children on intestinal absorption of 3-0 methyl-alpha-D-glucopyranose (3-M.G.) and oleic acid was studied in rats in vivo. Oleci acid absorption was unaffected by non-pathogenic E. coli but decreased by E. coli 0111, Salmonella paratyphi B., Shigella sonnei and Candida sp. This effect was probably explained by intestinal secretion diluting the test solution leading to a decreased diffusion gradient for solubilised fatty acid. Inhibition of sugar absorption occurred with bacterial suspensions of Staphylococcus aureus, Streptococcus faecalis, E. coli and Candida sp. and cell-free preparations of Staphylococcus aureus, Streptococcus faecalis, a non-pathogenic E. coli, Proteus sp., Klebsiella sp., Pseudomonas sp. and Candida sp. These effects were not explained by dilution of the test solution. This indicates that numerous micro-organisms and, in some instances, their cell-free preparations can interfere with intestinal active sugar transport. These findings may be relevant to the production of malabsorption in malnourished children who have a wide variety of micro-organisms contaminating their upper intestinal contents.     

Lower production of IL-17A and increased susceptibility to Mycobacterium bovis in mice coinfected with Strongyloides venezuelensis

The presence of intestinal helminths can down-regulate the immune response required to control mycobacterial infection. BALB/c mice infected with Mycobacterium bovis following an infection with the intestinal helminth Strongyloides venezuelensis showed reduced interleukin-17A production by lung cells and increased bacterial burden. Also, small granulomas and a high accumulation of cells expressing the inhibitory molecule CTLA-4 were observed in the lung. These data suggest that intestinal helminth infection could have a detrimental effect on the control of tuberculosis (TB) and render coinfected individuals more susceptible to the development of TB.     

Effect of surgical alteration of the rat gastrointestinal tract on the growth and development of Hymenolepis diminuta

Eight groups of rats were used to study the involvement of the enteric (ENS) and central (CNS) nervous systems in the development of Hymenolepis diminuta using surgical intestinal transection, or CNS denervation, or both procedures. The transection procedure was used to isolate the ENS of the small intestine from either orad and/or caudal portions of the alimentary system, while the CNS denervation was used to eliminate direct visceral efferent inputs from the CNS. Nine days after the surgical procedures, all rats were infected with 35 cysticercoids of H. diminuta. On 20 days postinfection, the infection intensity, tapeworm dry weight, tapeworm morphology, intestine length, and intestinal wet weight were recorded. Only the combination of the duodenal and ileal transections with a CNS denervation reduced infection intensity and prevented the increased intestinal length normally observed in infected rats. In contrast, none of the various intestinal transection procedures alone or CNS denervation alone had any effect on the survival, ability to produce oncospheres or morphology of the tapeworms. In conclusion, tapeworm survival is decreased when both CNS and ENS inputs into the small intestine are altered or absent.     

Cellular and luminal forms of rat intestinal calcium-binding protein as studied by counter ion electrophoresis

A novel method, termed counter ion electrophoresis, has been developed to identify calcium-binding proteins. In this procedure labeled calcium (${}^{45}\text{CaCl}{}_2$) is added to the lower (anode) chamber reservoir, and the protein sample is applied to the polyacrylamide gel in the upper (cathode) chamber reservoir. As the calcium migrates toward the cathode and the proteins move toward the anode, calcium-binding sites in the gel become labeled and gel slices, containing these sites, can be identified by liquid scintillimetry after solubilization. Application of this procedure to a study of the vitamin D-dependent calcium-binding protein in growing rats has shown that calcium-binding protein occurs consistently as two protein bands in material from mucosal scrapings, but only as one band (band 1) in material from isolated intestinal cells. Bands 1 and 2 are shown to behave as charge isomers, with band 2 more negatively charged. In weanling rats, material from mucosal scrapings yielded only band 1. When calcium-binding protein from mucosal scrapings of growing rats was prepared in the presence of phenylmethylsufonyl fluoride, the amount of band 2 was reduced. Incubation for 2 h at 37 °C of partially purified calcium-binding protein from mucosal scrapings transformed band 1 to band 2, a conversion inhibited by phenylmethyl-sulfonyl fluoride. Similar treatment of partially purified calcium-binding protein from isolated cells had no effect on band 1. It is concluded that band 1 is the cellular and native form of calcium-binding protein which is transformed enzymatically to band 2 in the presence of luminal material.     

Parasitic helminths from Sigmodon hispidus (Rodentia: Cricetidae) from seasonal and evergreen habitats in Costa Rica

The helminthological fauna of the cotton rat, Sigmodon hispidus in a tropical environment varies according to habitat and feeding behavior. Six species of nematodes (Longistriata adunca, Trichostrongylus sigmodontis, Strongyloides sigmodontis, Litomosoides carinii, Monodontus sp. and Protospirura sp.) and two species of cestodes (Hymenolepis diminuta and Raillietina sp.) were found in rats from extensive dry lands in Guanacaste where hot temperatures and heterogeneous diet are the rule. Only two species of nematodes (Longistriata adunca and Angiostrongylus costaricensis) were found in rats collected in a humid pineapple plantation in the Central Plateau (Alajuela) where mild temperatures predominate. A. costaricensis, a metastrongylid of medical importance, was found in 42% of them.     

Enteric parasites and HIV infection: occurrence in AIDS patients in Rio de Janeiro, Brazil

The occurrence of intestinal parasites, its relation with the transmission mechanism of HIV, and the clinical state of the AIDS patients, were analyzed in 99 Group IV patients (CDC, 1986), treated at "Hospital Universitário Pedro Ernesto" (HUPE), between 1986 and 1988. The group consisted of 79 (79.8%) patients whose HIV transmission mechanism took place through sexual contact and of 16 (20.2%) who were infected through blood. Feces samples from each patient were examined by four distincts methods (Faust et al., Kato-Katz, Baermann-Moraes and Baxby et al.). The most occurring parasites were: Cryptosporidium sp., Entamoeba coli and Endolimax nana (18.2%), Strongyloides stercoralis and Giardia lamblia (15.2%), E. histolytica and/or E. hartmanni (13.1%), Ascaris lumbricoides (11.1%) and Isospora belli (10.1%). Furthermore, 74.7% of the patients carried at least one species. Intestinal parasites were found in 78.5% of the patients who acquired the HIV through sexual intercourse and in 56.3% of those infected by blood contamination. The difference, was not statistically significant (p greater than 0.05). In the group under study, the increase of the occurrence of parasitic infections does not seem to depend on the acquisition of HIV through sexual contact. It appears that in developing countries, the dependency is more related to the classic mechanisms of parasites transmission and its endemicity.     

Goussia girellae n. sp. (Apicomplexa: Eimeriorina) in the opaleye, Girella nigricans

Goussia girellae n. sp. is described from the opaleye fish, Girella nigricans. Merogonic stages were observed in the apices of intestinal epithelial cells, in the lamina propria, and in extra-intestinal sites including liver, gills, and spleen. Gamonts were observed in the intestinal epithelial cells. Only unsporulated oocysts were detected in the intestine, and sporulation occurred when feces containing oocysts were incubated for 48 h in seawater at 21 degrees C. Oocysts are elongated (24.8 x 14.7 micron) with a wall about 200 nm thick and have no residuum, micropyle, or polar granule. Sporocysts are ellipsoid (8.5 x 4.5 micron), have a thin two-layered wall approximately 30 nm thick, and consist of two valves joined by a suture. Although moribund opaleye were also infected with Gyrodactylus sp., Cryptobia sp., Cardicola sp., and epitheliocystis organisms (chlamydia), all fish were heavily infected with G. girellae and morbidity was thus attributed to the coccidium.     

Adoptive transfer of the intestinal mast cell response in rats infected with Nippostrongylus brasiliensis.

The intestinal mast cells (IMC) were examined in normal and adoptively immunized rats infected with Nippostrongylus brasiliensis. An increase in the numbers of IMC was observed in infected recipients of thoracic duct lymphocytes (TDL) obtained from donor rats which had themselves been infected 10 days previously (Day 10 TDL). The increase in the number of IMC in the mucosa was related to the number of Day 10 TDL transferred into infected recipients. When TDL were fractionated into populations of cells either bearing (sIg⁺) or lacking (sIg^?) surface immunoglobulin, only sIg^? cells were able to confer the IMC response. Antigenic stimulation was necessary for the differentiation of intestinal mast cells. There was a marked difference between different strains of rats with regard to worm burden and intestinal mast cell kinetics although the increase in intestinal mast cells was always closely related to the final stage of the rapid phase of worm expulsion. These results are compatible with the concept that intestinal mast cells are derived from T cells and suggest that sIg⁺ cells do not influence IMC differentiation. Alternatively, the possibility that the transferred TDL regulate the differentiation of cells of host origin into IMC cannot be excluded.