Fucose Ameliorates Tritrichomonas sp.-Associated Illness in Antibiotic-Treated Muc2-/- Mice.

The mucus layer in the intestine plays a critical role in regulation of host-microbe interactions and maintaining homeostasis. Disruptions of the mucus layer due to genetic, environmental, or immune factors may lead to inflammatory bowel diseases (IBD). IBD frequently are accompanied with infections, and therefore are treated with antibiotics. Hence, it is important to evaluate risks of antibiotic treatment in individuals with vulnerable gut barrier and chronic inflammation. Mice with a knockout of the Muc2 gene, encoding the main glycoprotein component of the mucus, demonstrate a close contact of the microbes with the gut epithelium which leads to chronic inflammation resembling IBD. Here we demonstrate that the Muc2-/- mice harboring a gut protozoan infection Tritrichomonas sp. are susceptible to an antibiotic-induced depletion of the bacterial microbiota. Suppression of the protozoan infection with efficient metronidazole dosage or L-fucose administration resulted in amelioration of an illness observed in antibiotic-treated Muc2-/- mice. Fucose is a monosaccharide presented abundantly in gut glycoproteins, including Mucin2, and is known to be involved in host-microbe interactions, in particular in microbe adhesion. We suppose that further investigation of the role of fucose in protozoan adhesion to host cells may be of great value.

Malaria parasites and related haemosporidians cause mortality in cranes: a study on the parasites diversity, prevalence and distribution in Beijing Zoo.

BACKGROUND: Malaria parasites and related haemosporidian parasites are widespread and may cause severe diseases in birds. These pathogens should be considered in projects aiming breeding of birds for purposes of sustained ex situ conservation. Cranes are the 'flagship species' for health assessment of wetland ecosystems, and the majority of species are endangered. Malaria parasites and other haemosporidians have been reported in cranes, but the host-parasite relationships remain insufficiently understood. Morbidity of cranes due to malaria has been reported in Beijing Zoo. This study report prevalence, diversity and distribution of malaria parasites and related haemosporidians in cranes in Beijing Zoo and suggest simple measures to protect vulnerable individuals. METHODS: In all, 123 cranes (62 adults and 61 juveniles) belonging to 10 species were examined using PCR-based testing and microscopic examination of blood samples collected in 2007-2014. All birds were maintained in open-air aviaries, except for 19 chicks that were raised in a greenhouse with the aim to protect them from bites of blood-sucking insects. Bayesian phylogenetic analysis was used to identify the closely related avian haemosporidian parasites. RESULTS: Species of Plasmodium (5 lineages), Haemoproteus (1) and Leucocytozoon (2) were reported. Malaria parasites predominated (83% of all reported infections). The overall prevalence of haemosporidians in juveniles was approximately seven-fold higher than in adults, indicating high susceptibility of chicks and local transmission. Juvenile and adult birds hosted different lineages of Plasmodium, indicating that chicks got infection from non-parent birds. Plasmodium relictum (pSGS1) was the most prevalent malaria parasite. Mortality was not reported in adults, but 53% of infected chicks died, with reports of co-infection with Plasmodium and Leucocytozoon species. All chicks maintained in the greenhouse were non-infected and survived. Species of Leucocytozoon were undetectable by commonly used PCR protocol, but readily visible in blood films. CONCLUSION: Crane chicks often die due to malaria and Leucocytozoon infections, which they likely gain from wild free-living birds in Beijing Zoo. Molecular diagnostics of crane Leucocytozoon parasites needs improvement. Because the reported infections are mainly chick diseases, the authors recommend maintaining of juvenile birds in vector-free facilities until the age of approximately 6 months before they are placed in open-air aviaries.

Intestinal pathogen clearance in children with severe acute malnutrition is unrelated to inpatient morbidity.

BACKGROUND & AIMS: Children with Severe Acute Malnutrition (SAM) often suffer from diarrhea, which is associated with increased mortality. The contribution of intestinal bacteria, parasites and viruses to morbidity such as diarrhea in SAM remains poorly understood. To evaluate their association with clinical outcomes, we detected stool pathogens in children with SAM at hospital admission and after clinical stabilization prior to discharge. METHODS: 15 intestinal pathogens, fecal calprotectin and C-reactive protein (CRP) were determined at admission and after clinical stabilization in children aged 8-59 months (n = 47) hospitalized in Malawi for complicated SAM. Differences in fecal pathogens, intestinal and systemic inflammation, and clinical outcomes between time points were evaluated using the Wilcoxon Signed-Rank test or Wilcoxon rank-sum test. RESULTS: On admission pathogens were present in nearly all children and after clinical stabilization many were cleared with only 55% of children still harboring a pathogen (89% vs. 55%, p = 0.001). Nosocomial infections were infrequent. The pathogens Giardia lamblia and Shigella spp. were most likely to persist. After clinical stabilization, fecal calprotectin was higher in children harboring a pathogen (median (IQR): 383 mg/kg (903-149 mg/kg) vs 140 mg/kg (300-71 mg/kg), p = 0.03). CRP did not correlate with fecal calprotectin levels nor was it associated with pathogen detection. Presence of stool pathogens was not associated with clinical outcomes such as diarrhea. CONCLUSIONS: Fecal pathogens were very common and cleared in most children with complicated SAM treated with antibiotics. The presence of stool pathogens after stabilization was associated with increased intestinal inflammation but not with clinical outcomes. (http://www.isrctn.com/ISRCTN13916953).

A review of mortality from parasitic and vector-borne diseases in the U.S. Air Force from 1970 to 2012.

We review a unique set of documents, death certificates, cataloged in the U.S. Air Force Mortality Registry database, which tracks deaths for all current and retired service members. We screened the records for all deaths caused by parasitic, vector-borne, or zoonotic diseases between 1970 and 2013. There were 78 deaths caused by a variety of diseases such as amebiasis, malaria, strongyloidiasis, schistosomiasis, and pneumocystosis. We compare these deaths to U.S. national deaths. U.S. Air Force service members are more likely to die from malaria, strongyloidiasis, and Q fever than the average American but are less likely to die from pneumocystosis.

Experimental infections with the protozoan parasite Histomonas meleagridis: a review.

In recent years, a number of studies about Histomonas meleagridis, and more specifically about experiments in vivo involving H. meleagridis to investigate the pathogenicity and efficacy of drugs or vaccines, have been published. Together with older publications, a considerable amount of information about experimental infections with H. meleagridis exist, which is helpful for planning future animal studies and can reduce the number of birds used in such studies toward better animal welfare. One hundred sixty-seven publications describing experimental infections with H. meleagridis were published in scientific journals between 1920 and 2012. One hundred forty-two of these publications describe infections of turkeys (Meleagris gallopavo) and 52 infections of chickens (Gallus gallus). In 18 studies, experiments involving other species were done. The most popular routes of infection were the intracloacal application of histomonal trophozoites from culture material, from lesions or from feces of infected birds, or using larvae of the cecal worm Heterakis gallinarum (83 studies) and the oral application of eggs or other stages of the cecal worm containing histomonal stages (83 studies). During the last 10 years, intracloacal application of trophozoites has become the most popular way to experimentally infect birds with H. meleagridis due to its high reproducibility and reliability. In most studies, infection doses of several 10,000 or 100,000 histomonal trophozoites were used for infection, and the resulting mortality in turkeys was more than 70 %. First mortality can occur as early as 6 days p.i.; peak mortality usually is 13-15 days p.i. Lower infection doses may delay mortality about 2 days. In chickens infected by the intracloacal route, mortality and clinical signs are rare, but infection rates are similar. Cecal lesions can be observed from 3 to 4 days p.i., lesions up to 3 weeks p.i.; liver lesions may be lacking completely or be present only in a small number of birds. In most studies infecting birds with Heterakis eggs containing histomonal stages, several 100 to 1,000 Heterakis eggs were used. However, lower doses might be sufficient, as infection with as few as 58 eggs per bird caused a mortality up to 90 % in turkeys. Clinical symptoms start 9 days p.i., and first mortality occurs after 12 days, while most of the infected birds die between 19 and 21 days p.i. The infectivity of Heterakis eggs containing histomonal stages for chickens is similar as for turkeys, but mortality and clinical signs are rare. Further infection was done by oral application of histomonal trophozoites either grown in culture or using lesions or feces of infected birds (26 studies). These yielded very mixed results, with infection rates between 0 and more than 80 % in turkeys and chickens. After successful oral infection of turkeys, mortality occurs at roughly the same time as after intracloacal infection. Further 18 studies employed seeder birds to infect in-contact birds. Other means of infection were exposure to contaminated soil or litter (22 studies), feeding contaminated earthworms (7 studies), intracecal inoculation (4 studies), or parenteral injection (4 studies). Main methods to assess the course of the infection were mortality, observation of clinical signs and pathological lesions, monitoring of the weight of the infected birds, and detection of the parasite by various methods.

The nature and consequences of coinfection in humans.

OBJECTIVE: Many fundamental patterns of coinfection (multi-species infections) are undescribed, including the relative frequency of coinfection by various pathogens, differences between single-species infections and coinfection, and the burden of coinfection on human health. We aimed to address the paucity of general knowledge on coinfection by systematically collating and analysing data from recent publications to understand the types of coinfection and their effects. METHODS: From an electronic search to find all publications from 2009 on coinfection and its synonyms in humans we recorded data on i) coinfecting pathogens and their effect on ii) host health and iii) intensity of infection. RESULTS: The most commonly reported coinfections differ from infections causing highest global mortality, with a notable lack of serious childhood infections in reported coinfections. We found that coinfection is generally reported to worsen human health (76% publications) and exacerbate infections (57% publications). Reported coinfections included all kinds of pathogens, but were most likely to contain bacteria. CONCLUSIONS: These results suggest differences between coinfected patients and those with single infections, with coinfection having serious health effects. There is a pressing need to quantify the tendency towards negative effects and to evaluate any sampling biases in the coverage of coinfection research.

Enteroparasitosis prevalence and parasitism influence in clinical outcomes of tuberculosis patients with or without HIV co-infection in a reference hospital in Rio de Janeiro (2000-2006)

Tuberculosis and intestinal parasites affect primarily low social and economic level populations, living clustered in precarious habitational settings. One of the interesting aspects of this interaction is the parasitism influence in cellular response to tuberculosis. In the present study, we evaluated the prevalence of enteroparasitosis in tuberculosis patients, HIV-infected and non HIV infected, and we observed the influence of helminth presence in the response to tuberculin skin test (TST) and tuberculosis clinical outcomes. From 607 clinical records reviewed, 327 individuals met the study inclusion criteria and did not present any exclusion criteria. The prevalence of enteroparasites observed was 19.6 percent. There was no significant association among TST result and the variables related to the presence of: helminthes, protozoa, and stool test for parasites result (p>0.5). Considering the survival of this cohort, we may observe that there is no significant difference (p>0.05) between the survival curves of parasited and non parasited individuals. Solely the variable "eosinophils" presents a statistically significant association (p<0.001) with helminthes, all other associations are considered not significant. Our findings neither show an association between helminthic infection and a favorable tuberculosis outcome, nor between parasitism and TST response, unlike other in vitro studies. Apparently, experimental data do not correspond to the clinical findings.

Systemic histomoniasis associated with high mortality and unusual lesions in the bursa of Fabricius, kidneys, and lungs in commercial turkeys.

An outbreak of systemic histomoniasis in 9-to-11-wk-old meat-type male turkeys associated with high mortality is reported. Clinical signs in turkeys included anorexia, depression, diarrhea, loss of weight, and increased mortality between 7 and 13 wk of age. Seven-week cumulative mortality in the turkeys of affected houses ranged from 24% in one to 68% in the other compared with 1.3% of turkeys in the house not affected by histomoniasis. Necropsy of the turkeys revealed enlargement of the livers, most of which had numerous pale white nodules ranging in size from 0.3 to 1.5 cm in diameter. Cecal walls were severely thickened, the lumens were distended with caseous cores, and the mucosa was ulcerated. The bursa of Fabricius in four birds was enlarged and contained pale yellow exudate in their lumens. The kidneys, pancreas, and spleens in a few birds had pale or yellow foci. Microscopically, there were multifocal necrosis and granulomatous inflammation in the liver, ceca, peritoneum, bursa of Fabricius, kidneys, lungs, pancreas, proventriculus, and in spleens associated with histomonads. Electron microscopy also confirmed the presence of histomonads in the liver and ceca. This is the first report of naturally occurring systemic histomoniasis in turkeys affecting the bursa of Fabricius, kidneys, lungs, pancreas, and proventriculus.

Enteroparasitosis prevalence and parasitism influence in clinical outcomes of tuberculosis patients with or without HIV co-infection in a reference hospital in Rio de Janeiro (2000-2006).

Tuberculosis and intestinal parasites affect primarily low social and economic level populations, living clustered in precarious habitational settings. One of the interesting aspects of this interaction is the parasitism influence in cellular response to tuberculosis. In the present study, we evaluated the prevalence of enteroparasitosis in tuberculosis patients, HIV-infected and non HIV infected, and we observed the influence of helminth presence in the response to tuberculin skin test (TST) and tuberculosis clinical outcomes. From 607 clinical records reviewed, 327 individuals met the study inclusion criteria and did not present any exclusion criteria. The prevalence of enteroparasites observed was 19.6%. There was no significant association among TST result and the variables related to the presence of: helminthes, protozoa, and stool test for parasites result (p>0.5). Considering the survival of this cohort, we may observe that there is no significant difference (p>0.05) between the survival curves of parasited and non parasited individuals. Solely the variable "eosinophils" presents a statistically significant association (p<0.001) with helminthes, all other associations are considered not significant. Our findings neither show an association between helminthic infection and a favorable tuberculosis outcome, nor between parasitism and TST response, unlike other in vitro studies. Apparently, experimental data do not correspond to the clinical findings.

Mitigation of lethal effects of Karlodinium veneficum and K. armiger on Sparus aurata: changes in haematocrit and plasma osmolality.

Between January and April 2000, several experiments were performed during a Karlodinium spp. proliferation in Alfacs Bay (Ebro delta, NW Mediterranean) to determine the effects of these dinoflagellates on sea bream Sparus aurata cultivated in the area. Moribund fish showed an increase in plasma osmolality together with a decrease in the haematocrit percentage compared to control fish. The efficacy of copper sulphate, hydrogen peroxide, potassium permanganate and formalin against Karlodinium spp. was also tested. None of these treatments had mitigation effects when applied in the presence of fish; on the contrary, lethal effects appeared at lower Karlodinium spp. densities compared to fish control groups. When a lytic agent, such as copper sulphate, was used as a water pre-treatment, in the absence of fish, Karlodinium spp. toxicity was significantly reduced. Protocols for water pre-treatments were studied as a potential tool for combating Karlodinium spp. in fish farms.

Incidence of histomonosis in turkeys in France since the bans of dimetridazole and nifursol.

Between April 2003 and March 2005, 113 outbreaks of histomonosis were recorded in standard turkey farms in France, and 15 cases were recorded in turkey breeding centres. Most of the cases were in north-west France, the principal farming area for turkeys. The majority of the cases occurred during the hottest months, from April to September. Large numbers of cases occurred among birds from four to eight weeks of age, but there were some cases in three-week-old birds and some in birds up to 17 weeks of age. In most of the standard turkey flocks the mortality was less than 10 per cent, but it was above 30 per cent in nearly 20 per cent of the outbreaks. In the breeding flocks, the average mortality was 60.2 per cent. The size of the flocks, the sex of the birds and the age at which the first clinical signs appeared did not seem to influence the mortality.

Experimental infections of Atlantic salmon Salmo salar with Spironucleus barkhanus.

Atlantic salmon Salmo salar L. (Salmonidae) were experimentally infected with Spironucleus barkhanus (Diplomonadida: Hexamitidae). Parasites were found in the blood 1 to 8 wk after infection, after which they disappeared from the blood and were found mainly in the internal organs (e.g. spleen and liver), eye socket or muscles. Mortality (38 out of 40 infected fish) occurred when fish had lesions in internal organs and/or on the body surface. Uninfected fish cohabiting with infected fish became infected after 4 wk, indicating direct transmission. There was no difference in susceptibility to spironucleosis between 3 different families of Atlantic salmon. All families developed the disease with a similar pattern of parasitaemia in the blood, similar clinical signs and gross pathology, and with very high mortality (29 out of 30). Clinical signs of systemic spironucleosis may include anemia, skin blisters, muscle ulcerations or unilateral exophthalmia. Gross pathologies include hemorrhaging of internal organs, splenomegaly or deformed (globulated) spleen, or granulomatous lesions in the spleen and liver.

Hexamita meleagridis (Spironucleus meleagridis) infection in chukar partridges associated with high mortality and intracellular trophozoites.

An outbreak of infectious catarrhal enteritis, associated with the flagellated protozoan Spironucleus meleagridis (syn. Hexamita meleagridis), is reported from a commercial flock of chukar partridges in California. The disease affected birds between the ages of 4 and 6 wk and resulted in diarrhea, listlessness, depression, and high mortality. Concurrent infection with other intestinal pathogens, including Cryptosporidia, group E Salmonella, long-segmented filamentous microorganisms (LSFMOs), and Rotavirus-like virus particles, was found in some but not all affected birds. Dermatitis of the face, shanks, and feet, suggestive of B-complex vitamin deficiency, was present in most affected birds as well. Flagellated protozoan parasites could be found in the lumen of the duodenum and jejunum and in the intestinal crypts. In some cases the flagellates were wedged between epithelial cells or were located intracellularly within cells of the mucosal epithelium and the intestinal lamina propria.

Cryptobia iubilans infection in juvenile discus.

Four commercial producers of discus (Symphysodon aequifasciatus) were found to have fish infested with the flagellate Cryptobia iubilans. Affected fish had granulomatous gastritis, and many also had granulomatous disease of other organs. The parasite had to be differentiated from the related flagellates Spironucleus spp, which induce different lesions. Transmission electron microscopy was found to be useful in detecting and identifying the parasite. Morbidity and mortality rates in the various fish populations appeared to be linked to a number of variables, including water quality, presence of other parasites and bacteria, diet, species, size, and age of the fish, and optimization of husbandry appeared to be important in alleviating the severity of disease. Metronidazole was not effective for treatment of C iubilans, but bath treatments with dimetridazole (80 mg/L for 24 hours, repeated daily for 3 days) or 2-amino-5-nitrothiazol (10 mg/L for 24 hours, repeated daily for 3 days) may be useful in decreasing the prevalence of infestation.

Iron enhancement of experimental infection of mice by Tritrichomonas foetus.

The ability of a microbial invader to acquire iron from its vertebrate host has been recognized as an important virulence mechanism in some pathogenic bacteria. We examined the involvement of similar mechanisms in an experimental infection of mice by a protozoan pathogen of cattle, Tritrichomonas foetus. In a series of experiments, outbred ICR mice were inoculated intraperitoneally with two strains of T. foetus, the moderately virulent KV-1 (approximately 5% mortality rate) and the highly virulent LUB-1MIP (approximately 80% mortality rate). Treatment of mice with ferric ammonium citrate (FeAC) (100 mg/kg per day intraperitoneally) increased the mortality rate caused by the KV-1 infection up to the level determined for the highly virulent strain. The treatment effect was dose dependent and required early administration of FeAC after inoculation of parasites and its continued supply for at least 3 subsequent days. Daily sampling of peritoneal exudate showed that the infection-enhancing effect of iron overload was associated with a stimulation of parasite multiplication, which in the case of KV-1 infection was strongly suppressed in untreated mice. Consistent with these findings, the strain of lower virulence (KV-1) showed considerably lower efficiency accumulating radiolabeled iron from transferrin and a low-molecular source [Fe(III)nitrilotriacetic acid] in vitro. The results indicate an involvement of iron uptake mechanisms by the parasite as a virulence factor in T. foetus infection.

Genetic variation in susceptibility to Trypanoplasma borreli infection in common carp (Cyprinus carpio L.).

Gynogenetic reproduction of homozygous females, or crossbreeding two homozygous animals, results in fish lines without genetic variation. Hybrid crosses are expected to express a more stable development than homozygous lines, the latter may have an important value for gaining insight into genetic components of host resistance to parasite infection. We examined the antibody response of carp (Cyprinus carpio L.) to infection with Trypanoplasma borreli. Outbred carp responded with a production of specific antibodies, but highly susceptible isogenic hybrid carp did not. This suggests an apparent relationship between susceptibility and the lack of specific antibody production. This relation was partially confirmed by the passive transfer of immunity with immune plasma. In addition, two isogenic homozygous carp lines were highly susceptible to the trypanoplasm (100% mortality), in contrast with outbred carp, the majority of which survived infection. None of the carp in either homozygous carp line produced an antibody response to parasite-unrelated antigen (DNP-KLH). This suggests that the low antibody response was not entirely due to a poor state of health, but that these carp have a genetically predetermined low antibody response.

Mortality in Atlantic salmon (Salmo salar) associated with trichodinid ciliates.

A protozoan infection (Trichodina truttae) was identified in captive Atlantic salmon (Salmo salar) kelts that died in spring of 1988 and 1989. Fish with intense infections showed signs of listlessness, erratic swimming and inappetence. The infection induced excessive mucus secretion, epithelial sloughing and lesions that probably permitted entry of opportunistic bacteria which eventually caused ulcers and death. A seawater bath for 30 min each week for 4 wk effectively controlled the parasite.

Developmental time and mortality of the reduviid bug Triatoma infestans with differential exposure to coprophagic infections with Blastocrithidia triatomae (Trypanosomatidae).

Developmental time and survival in larvae of the reduviid bug Triatoma infestans were studied in uninfected groups and in those exposed to a coprophagic infection with Blastocrithidia triatomae. Addition to young uninfected larvae of (a) different numbers of infected bugs, (b) infected and uninfected bugs, and (c) fresh or dry infectious feces were compared. Retardation of development was evident in groups given infected larvae or fresh feces. Mortality rates were correlated with infection rates and were higher in groups given more infected bugs, independent of the presence of uninfected bugs. Therefore, bugs did not discriminate between feces from infected and uninfected bugs, or they did not reject infectious feces. Dry feces had to be redissolved with fresh feces before infection was possible.