The endocannabinoid system in canine Steroid-Responsive Meningitis-Arteritis and Intraspinal Spirocercosis.

Endocannabinoids (ECs) are involved in immunomodulation, neuroprotection and control of inflammation in the central nervous system (CNS). Activation of cannabinoid type 2 receptors (CB2) is known to diminish the release of pro-inflammatory factors and enhance the secretion of anti-inflammatory cytokines. Furthermore, the endocannabinoid 2-arachidonoyl glycerol (2-AG) has been proved to induce the migration of eosinophils in a CB2 receptor-dependent manner in peripheral blood and activate neutrophils independent of CB activation in humans. The aim of the current study was to investigate the influence of the endocannabinoid system in two different CNS inflammatory diseases of the dog, i.e. Steroid-Responsive Meningitis-Arteritis (SRMA) and Intraspinal Spirocercosis (IS). The two main endocannabinoids, anandamide (AEA) and 2-AG, were quantified by mass spectrometry in CSF and serum samples of dogs affected with Steroid- Responsive Meningitis-Arteritis in the acute phase (SRMA A), SRMA under treatment with prednisolone (SRMA Tr), intraspinal Spirocercosis and healthy dogs. Moreover, expression of the CB2 receptor was evaluated in inflammatory lesions of SRMA and IS and compared to healthy controls using immunohistochemistry (IHC). Dogs with SRMA A showed significantly higher concentrations of total AG and AEA in serum in comparison to healthy controls and in CSF compared to SRMA Tr (p<0.05). Furthermore, dogs with IS displayed the highest ECs concentrations in CSF, being significantly higher than in CSF samples of dogs with SRMA A (p<0.05). CSF samples that demonstrated an eosinophilic pleocytosis had the highest levels of ECs, exceeding those with neutrophilic pleocytosis, suggesting that ECs have a major effect on migration of eosinophils in the CSF. Furthermore, CB2 receptor expression was found in glial cells in the spinal cord of healthy dogs, whereas in dogs with SRMA and IS, CB2 was strongly expressed not only in glial cells but also on the cellular surface of infiltrating leukocytes (i.e. neutrophils, eosinophils, lymphocytes, plasma cells, and macrophages) at lesion sites. The present study revealed an upregulated endocannabinoid system in dogs with inflammatory CNS diseases, highlighting the endocannabinoid system as a potential target for treatment of inflammatory CNS diseases.

[THE FIRST CASE OF OCULAR THELAZIASIS IN CROATIA].

The first case of ocular thelaziasis in a human male patient in Croatia is presented. Thelaziasis is a zoonosis caused by nematodes of the genus Thelazia, parasites of the conjunctival bags or tear ducts of mammals and birds. Two types of the genus Thelazia (T.) have been described as causes of infection in humans, T. callipaeda and T. californiensis. To date, less than 300 thelaziasis cases in humans have been reported. This zoonosis is very rare in humans in European countries, with a high incidence in Asian countries, especially in China, Thailand and Japan. Because of the high prevalence of the parasites in the Far East, T. callipaeda is called 'Oriental eye worm'. The first case of thelaziasis in Europe was described in 2008 in Italy and France, where cases in animals had already been reported. Seasonal occurrence of thelaziasis in Europe depends on the presence of the vector, fruit flies of Drosophilidae family, Phortica variegate as the most common type. Adult worm is milky white, females grow to 20 mm and males up to 12 mm. Dogs and cats are the most common sources of infection for humans, which occurs as unilateral ocular infection. The clinical picture of infection is similar to bacterial and allergic conjunctivitis with tearing and foreign body sensation. After removal of worms, clinical signs quickly disappear and there is no need for anthelmintic treatment. In the treatment of secondary infections, local antibiotics and corticosteroids can be applied. The 82-year-old male patient presented to outpatient ophthalmology clinic for occasional sensation of pain, itching, redness and tearing in his left eye during the last few days. His left eye was blind due to previous retinal detachment and had severe conjunctival and ciliary infection with large corneal abscess. Worm-like movement in the lateral canthus was observed. After topical anesthesia, seven worms were removed. Upon surgical extirpation of the parasite, the diagnosis of thelaziasis was verified by microbiological identification. Only two cases of Thelazia in dogs were reported in Croatia, in December 2013 and January 2014. It is important to bear in mind this cause of eye infections, especially when caused by larval stages that are difficult to identify. Untimely diagnosis and inadequate treatment lead to extended illness and complications. The appearance of this parasite in Croatian patients suggests the need for inclusion of the pathogen in the differential diagnosis of bacterial or allergic conjunctivitis.

Effects of a muscle-infecting parasitic nematode on the locomotor performance of their fish host.

The southern flounder Paralichthys lethostigma, host to the nematode Philometroides paralichthydis that is embedded in place of the inclinator muscles of the dorsal and anal fin elements, is hypothesized to impair two aspects of locomotor performance (swimming and burying capacity). Peak swimming acceleration and both measures of burying performance did not differ between infected and uninfected fish, whereas swimming velocity of infected fish was significantly lower than that of uninfected fish. Smaller infected fish swam at significantly slower speeds than smaller uninfected fish, whereas there was no difference among larger fish. Neither the location nor the number of worms affected either swimming or burying performance. The decrease in swimming velocity observed in smaller infected fish may be sufficient in rendering them more vulnerable to predation and environmental stressors.

Swim bladder nematodes (Anguillicoloides crassus) disturb silvering in European eels (Anguilla anguilla).

The introduced parasite Anguillicoloides crassus is thought to play an important role in the decline of freshwater eel (Anguilla spp.) populations. These nematodes are known to negatively affect many fitness-related traits in eels. We used experimental infections to study the effect of A. crassus on the relative size or mass of organs, and the expression of functionally relevant genes (total of 12 parameters) that are involved in the silvering process of Anguilla anguilla. Our results showed that the liver mass, the hemoglobin α-chain, and androgen receptors α expression levels were significantly higher in infected eels, whereas the freshwater rod opsin expression level and the gut mass were significantly lower in infected eels. Our results suggested that infected eels were at a more advanced stage in the silvering process than uninfected counterparts of similar size. These results may be explained by 2 hypotheses. First, A. crassus could trigger physiological mechanisms involved in the silvering process as a side-effect of infection. Second, eels may adjust their life history traits in response to infection. The implications for eel migration and reproductive success may be either negative or positive, depending on whether the response to A. crassus infection results in an additional cost of the parasite or is due to the phenotypic plasticity of the host.

Variation in the sex ratio of Rhabdochona fortunatowi (Spirurida: Rhabdochonidae) in Capoeta capoeta gracilis (Cypriniformes: Cyprinidae), relative to levels of infection, host size and temperature.

In the present study, 81 specimens of Capoeta capoeta gracilis (Keyserling, 1861) were collected from the Shiroud River, the Caspian drainage basin, Iran in June and October 2007. The fish were examined for infection with the nematode Rhabdochona fortunatowi (Dinnik, 1933). Nematodes were counted and sexed, then the sex ratio and intestinal site preference of the R. fortunatowi individuals and the intersexual interactions of the parasites were investigated. Significant differences were observed in the prevalence and intensity of infection in relation to host size and sampling season, but not host sex. Parasite burden (mean intensity) was higher in October than in June and the results revealed a decrease in female-to-male sex ratio (FMR) in the fish in October compared to the ones in June. In other words, as the mean intensity of infection of R. fortunatowi increases, the proportion of male worms increases, too. The female-biased sex ratio in June was replaced by a male-biased one in October. Nematode distribution rose to a significant peak in the mid-region of the fish intestine relative to the anterior and posterior parts. Some changes in the distribution of male and female worms in different parts of the host intestine were also observed during June and October. Density-dependent selection and intersexual competition seem to be the main factors driving such a shift in the sex ratio and its variation in different parts of the host intestine.

Short report: case of gnathostomiasis in Beijing, China.

A 59-year-old woman sought treatment of for creeping eruption and erythematous plaques associated with high fever and systemic symptoms. She had a history of eating undercooked freshwater fish raised in Beijing 10 days before admission and reported no travel during the previous year. Blood examination showed eosinophila and ultrasonography detected multiple hypoechoic areas in the liver and spleen. Western blot test detected specific antibodies to the larvae of Gnathostoma spinigerum. Cutaneous and visceral larva migrations associated with G. spinigerum were diagnosed. Twenty-three cases in 12 provinces have been reported in the Chinese literature but none have been reported in English.

Fever in travelers returning from tropical areas: prospective observational study of 613 cases hospitalised in Marseilles, France, 1999-2003.

BACKGROUND: Febrile travelers may pose a diagnostic challenge for Western physicians who are frequently involved in the assessment of these patients but unfamiliar with tropical diseases. Evaluation of this situation requires an understanding of the common etiologies, which are associated with the demographics of travelers and the destinations. METHODS: We conducted a 5-year prospective observational study on the etiologies of fever in travelers returning from the tropics admitted to the infectious and tropical diseases unit of a university teaching hospital in Marseilles, France. RESULTS: A total of 613 patients were enrolled, including 364 migrants (59.4%), 126 travelers (20.6%), 37 visitors (6%), 24 expatriates (3.9%), and 62 patients (10.1%) who could not be classified. Malaria was the most common diagnosis (75.2%), with most cases (62%) acquired by migrants from the Comoros archipelago and who had traveled to these islands to visit friends and relatives. Agents of food-borne and water-borne infections (3.9%) and respiratory tract infections (3.4%) were also frequently identified as the cause of fever. Other infections included emerging diseases such as gnathostomiasis, hepatitis E infection and rickettsial diseases, as well as common infections or exotic diseases. CONCLUSIONS: Although we have identified here various causes of imported fever, 8.2% of the fevers remained unexplained. An improved approach to diagnosis may allow for the discovery of new diseases in travelers in the future.

European eels, Anguilla anguilla (L.), infected with Anguillicola crassus exhibit a more pronounced stress response to severe hypoxia than uninfected eels.

The parasite, Anguillicola crassus is a non-native species that infects naive European eels, Anguilla anguilla, and causes pathological damage to the swimbladder, potentially compromising their ability to cope with hypoxic conditions. This study aimed to elucidate whether anguillicolosis exacerbates the stress responses to exposure to hypoxic water, conditions that have been implicated in mass mortalities of wild infected European eels. Blood parameters in infected and uninfected eels were measured during exposure to severe hypoxia over an 8-h period. Infected fish showed significantly higher levels of plasma cortisol compared with uninfected eels after 4 h of hypoxia. Uninfected fish showed an almost twofold increase in plasma glucose after 8-h exposure to hypoxia but infected fish showed no significant change, so that the plasma glucose concentration was significantly higher in uninfected eels than in infected eels. Both groups showed similar elevations in blood haematocrit, suggesting a similar catecholamine response in infected and uninfected eels. The lack of a hyperglycaemic response in infected eels, despite indirect evidence of a catecholamine response to hypoxia, may reflect an increase in glucose turnover. The data suggest that anguillicolosis results in a significantly greater corticosteroid stress response to hypoxia accompanied by a higher metabolic cost.

Experimental infection of laboratory animals and sheep with Gongylonema pulchrum in Japan.

Japanese White rabbits, Wistar rats, ddY mice, Suffolk sheep, and a domestic cat were each orally inoculated with 20-140 third-stage larvae (L3) of Gongylonema pulchrum, isolated from naturally infected dung beetles captured in Aomori Prefecture. Worm recovery rates were 40.0-72.0% in rabbits at 7, 14, and 19 weeks post-infection (PI) and 3.3-25.0% in rats at 19 weeks PI. Those in 2 sheep at 7 weeks PI showed 53.6% and 29.3%. No worms were recovered from the mice and the cat. In the susceptible animals, many worms were found in the esophagus, and a few were present in the pharyngeal mucosa, tongue, buccal mucosa, and cardiac portion of the stomach wall. No distinct morphological differences were observed in the worms from rabbits and sheep. These results indicate that rabbits are very suitable experimental definitive hosts for G. pulchrum.

Susceptibility of several species of Cyprinidae and Salmonidae freshwater fish to larval Gnathostoma nipponicum infection.

Susceptibility of five species of Cyprinidae and Salmonidae freshwater fish to the early third-stage larvae (EaL3) and advanced third-stage larvae (AdL3) of Gnathostoma nipponicum infection were examined. Two fish species inoculated orally with EaL3 were infected, and AdL3 were recovered from them with rate of 21.0% in Tribolodon hakonensis and 0.5% in Cyprinus carpio at 30 days postinoculation (PI). Attempts to infect five fish species with AdL3 were all successful. The recovery rate of AdL3 was 69.0% in T. hakonensis, 47.5% in Carassius auratus subsp., 35.0% in C. carpio, 53.0% in Oncorhynchus masou, and 32.0% in O. mykiss at 10 days PI. These results confirmed that the Cyprinidae and Salmonidae fish species reported here were susceptible to larval G. nipponicum infection and AdL3 had higher infectivity to them than the EaL3.

Changes in gas composition in the swimbladder of the European eel (Anguilla anguilla) infected with Anguillicola crassus (Nematoda).

The effect of Anguillicola crassus (Nematoda) on gas composition in the swimbladder of eels (Anguilla anguilla) was studied using mass spectrometry in feral eels from two German rivers and in experimentally infected eels. In both naturally and experimentally infected eels significant correlations were observed between the proportion of oxygen in the swimbladder and level of infection with Anguillicola crassus. In swimbladders of naturally infected feral eels the contribution of oxygen to swimbladder gas was reduced by 36-62.9% and in experimentally infected eels it was reduced by 11.4-57% compared to uninfected controls. The proportion of CO2 appeared to be lower in infected swimbladders compared to uninfected ones. However, this change was not significant. The findings are discussed in relation to an altered structure of the swimbladder wall due to the parasite.