The Vector-Borne Zoonotic Nematode Thelazia callipaeda in the Eastern Part of Europe, with a Clinical Case Report in a Dog in Poland

Thelazia callipaeda is a zoonotic nematode transmitted by drosophilid flies. It causes ocular thelaziosis, a disease of carnivores, such as dogs, cats, and foxes, and also humans. The parasite has thus far been observed in various areas of Eurasia, including 20 countries within Europe. The present study documents its presence in the south-east region of Poland, near the Ukraine border. An adult nematode was removed from the conjunctival sac of a dog showing ocular inflammation and purulent discharge. The dog’s precise origin is unknown. Based on its localization and morphometrical features, the nematode was identified as a Thelazia callipaeda adult male. The present study is the first report of T. callipaeda in a dog in Poland.

Vaccination with novel low-molecular weight proteins secreted from Trichinella spiralis inhibits establishment of infection

Trichinella spiralis muscle stage larvae (mL1) produce excretory-secreted products (ESPs), a complex mixture of protein, which are believed to be important for establishing or maintaining an infection niche within skeletal muscle and the intestine. Studies of both whole ESPs and individual cloned proteins have shown that some ESPs are potent immunogens capable of eliciting protective immune responses. Here we describe two novel proteins, Secreted from Muscle stage Larvae SML-4 and SML-5 which are 15 kDa and 12 kDa respectively. The genes encoding these proteins are highly conserved within the Trichinellids, are constituents of mL1 ESP and localized in the parasite stichosome. While SML-5 is only expressed in mL1 and early stages of adult nematode development, SML-4 is a tyvosylated glycoprotein also produced by adult nematodes, indicating it may have a function in the enteral phase of the infection. Vaccination with these proteins resulted in an impaired establishment of adult stages and consequently a reduction in the burden of mL1 in BALB/c mice. This suggests that both proteins may be important for establishment of parasite infection of the intestine and are prophylactic vaccine candidates.

The first case of autochthonous subcutaneous dirofilariasis (Dirofilaria repens) in a dog from Białowieża (NE Poland) and possible threat posed to inhabitants of Białowieża Primeval Forest area

We present the first case of dirofilariasis in a dog from Białowieża village located in the primeval European forest—Białowieża Primeval Forest (NE Poland). Molecular analysis of adult nematode specimens isolated from subcutaneous tissue confirmed the infection with Dirofilaria repens. An adult male dog has not travelled out of the Białowieża village for at least five years; therefore, we assume this is the autochthonous case of the disease. We discuss possible inter- and intra-species transmission routes of dirofilariasis on this territory, which is inhabited by diverse community of wild carnivores, domestic animals, and humans. We also discuss the likely sources of the disease in this, highly biodiverse unique European forest complex. We underline the lack of attention to this problem and its importance for veterinary, wildlife, and human health safety.

Giant kidney worm: novel report of Dioctophyma renale in the kidney of a dog in Greece

SummaryDioctophyma renale is the largest nematode that infects domestic mammals and is the aetiologic agent of a serious renal disease, dioctophymatosis. It has an indirect life cycle with carnivores serving as final hosts and earthworms as intermediate hosts. The parasite can infect humans with signifi cant zoonotic potential. The pathogenesis of dioctophymatosis is mainly associated with the extent of renal atrophy caused by the parasites, the risk of bilateral renal infestation and the location of the parasite (extrarenal cases). Clinical diagnosis is challenging, and the only treatment option is nephrectomy or nephrotomy to remove the adult nematode. A 6-year-old female crossbreed dog presented with tachypnea, tachycardia and severe hematuria, but died shortly after presentation. Postmortem examination found the right kidney was enlarged and two adult nematodes were found in the renal pelvis. The left kidney was normal. The nematodes were collected and submitted for identifi cation. The two specimens were identifi ed as D. renale using specific identifi cation keys. Herein we present the first case of renal parasitosis by the nematode D. renale in a dog from Greece. This case highlights the need for investigation of the actual prevalence of the parasite and the use of measures for the control of its expansion aiming the protection of dogs and public health.

AN OPHTHALMOLOGIC CASE OF DIROFILARIASIS: CLINICAL ASPECTS, DIAGNOSIS, PREVENTION

Objective: to characterize the macroscopic diagnosis, sources of infection, and ways of prevention using the example of an ophthalmic case of dirofilariasis. Material and methods. The work presents an ophthalmologic case of dirofilariasis in a 27 year-old female patient and describes the macroscopic diagnosis of helminthiasis. Results. The article deals with actual issues of one of the transmissible zoonotic biohelminthiasis - human dirofilariasis. It gives a historical perspective of the disease and the data about the frequency of dirofilariasis in Belarus. The article describes a clinical case of human dirofilariasis in Gomel first caused by hypodermic migration of nematode larva and then by parasitization of the conjunctiva by an adult nematode. The male Dirofilaria repens was found and identified in the female patient. The fact of local infection was established, morphological diagnostic features of the helminth were defined. Preventive measures were recommended. Conclusion. In Gomel, dirofilariasis has a sporadic character, but some cases of indigenous infection can be found. Further studies of the epidemiology of the disease are required.

The oxygen consumption rates of different life stages of the endoparasitic nematode

The oxygen consumption rates of different life stages of the endoparasitic nematode, Pratylenchus zeae (Nematoda: Tylenchida) during non- and post-anhydrobiosisPratylenchus zeae, widely distributed in tropical and subtropical regions, is an endoparasite in roots of maize and other crop plants. The nematode is attracted to plant roots by CO2 and root exudates and feeds primarily on cells of the root cortex, making channels and openings where the eggs are deposited, with the result that secondary infection occurs due to bacteria and fungi. Nothing is known about the respiration physiology of this nematode and how it manages to survive during dry seasons. To measure the oxygen consumption rate (VO2 ) of individual P. zeae (less than half a millimeter long), a special measuring technique namely Cartesian diver micro-respirometry was applied. The Cartesian divers were machined from Perspex, and proved to be more accurate to measure VO2 compared with heavier glass divers used in similar experiments on free living nematodes. An accuracy of better than one nanoliter of oxygen consumed per hour was achieved with a single P. zeae inside the diver. Cartesian diver micro-respirometry measurements are based in principle on the manometric changes that occur in a fl otation tube in a manometer set-up when oxygen is consumed by P. zeae and CO2 from the animal is chemically absorbed. VO2 was measured for eggs (length: < 0.05 mm), larvae (length: 0.36 mm) and adults (length: 0.47 mm) before induction to anhydrobiosis. P. zeae from infected maize roots were extracted and exposed aseptically to in vitro maize root cultures in a grow cabinet at 50 % to 60% relative humidity at 28 ºC using eggs, larvae and adults. VO2 was also measured for post-anhydrobiotic eggs, larvae and adults by taking 50 individuals, eggs and larvae from the culture and placing them in Petri-dishes with 1% agar/water to dry out for 11 days at 28 ºC and 50% relative humidity. The VO2 was measured after the anhydrobiotic eggs, larvae and adults were re-hydrated for 12 hours in a high humidity atmosphere. The average VO2 value found for ten consecutive measurements during a 50 minute period of one adult using the diver technique was 32.8 nanoliter per hour. The differences between the ten VO2 values were less than 3.5 %, an indication of the accuracy of the diver measurements. The average VO2 values from ten measurements per life stage, expressed in nanolitres per hour per life stage of the pre-anhydro-biotes (eggs: 7.96; larva: 6.13; adult: 26.04) were compared with those of post-anhydrobiotes 12 hours after anhydrobiosis. The average VO2 values of the post-anhydrobiotes for the three life stages (egg: 19.34; larva: 14.17; adult: 32.86) were statistically signifi cantly higher in comparison with the pre-anhydrobiotes. The reasons for the difference are that high concentrations of metabolites, probably in the form of trehalose, accumulate during the anhydrobiosis stage to be utilized during the post-anhydrobiotic revival period. The oxygen consumption rate was also expressed in nanolitres per hour per microgram adult nematode after applying the following equation taken from the literature: M = a2 x b/16 x 1000 where M = mass (µg) of adult nematode; a = largest body width (µm); b = body length (µm). Using this equation it was found that one gram P. zeae uses 503 times more oxygen compared with one gram mammal the size of a cow. This high specifi c oxygen consumption rate (MO2 ) is a direct indication of the large metabolic damage this endoparasitic nematode can have on the metabolic substrates provided by the roots of the various plant crops it parasitize.

Checklist of the adult nematode parasites of fishes in freshwater localities from Mexico

Based on original data gathered from fieldwork during the last years and from previous records from all published accounts, a checklist of the adult nematode parasites of freshwater fishes from Mexico is presented. The checklist is organized as a nematode-host list and comprises taxonomic and geographic distributional information. In total, the checklist includes 70 taxa (50 identified at species level) pertaining to 13 families. These taxa have been collected from 107 freshwater fish taxa in 198 localities along the Mexican Republic. The information we provide herein indicates that sampling effort has been concentrated in Central and South East Mexico, with the Northern region remaining mostly unexplored. The proportion of endemic nematodes is high in the country (74%, i.e., 37 of the 50 taxa identified at species level). The family Rhabdochonidae displays the highest species richness (12 species), and Rhabdochona kidderi is the most widespread nematode species in the country. Cichlids represent the host group with the largest number of samples in Mexico. Finally, we present a list containing new records of larval nematodes from localities in the states of Michoacán, Nayarit, Oaxaca, Tamaulipas and Veracruz.