Epizootiological Studies Research Articles

Ovicidal effect of the modern disinfectant on exogenous stages of development of nematodes Trichuris skrjabini

Epizootiological monitoring studies on parasitoses of domestic ruminants indicate that one of the most common causes of nematodes of the digestive tract in large and small cattle are helminths of the genus Trichuris. Those helminths develop directly – without intermediate hosts, and their embryonic stages became invasive in the environment under favorable conditions. The eggs of those parasites are incredibly resistant and can be infective for a long time contaminating environmental objects. So, to improve the parasitological situation in livestock farms, we have to look for the most effective methods of disinfestation of environmental objects. This study aimed to establish the ovicidal effect of the modern disinfectant “Arquadez-plus” on eggs of nematodes Trichuris skrjabini parasitizing sheep. This product's high level of ovicidal efficiency was seen in experimental cultures of nematodes' eggs at 1.5 % concentration and 60 min exposure (94.2 %) and 2.0 % concentration and 10–60 min exposure (98.3–100.0 %). The ovicidal effect of “Arquadez-plus” on eggs of T. skrjabini was seen as a cessation of development; shrinking embryo plugs destruction, the release of underdeveloped larvae from eggs, and their death. During the use of this disinfectant, the changes in morphometric data of Trichuris eggs in test cultures were noticeable. At the most effective disinfectant concentrations and exposures, the dimensions of eggs were changed significantly: length smaller by 3.8–3.9 % (71.9–72.0 μm) and width more significant by 5.0–5.2 % (34.9–35.0 μm) as compared to those parameters in control (74.8 and 33.2 μm). This is evidence of the violations in nematodes' egg development. The data obtained allow us to recommend the disinfectant of domestic production, “Arquadez-plus”, for effectively controlling and preventing trichurosis in sheep on livestock farms.

Leishmaniosis in Greece: The Veterinary Perspective.

Leishmaniosis caused by the protozoon Leishmania infantum that is transmitted through the bites of infected phlebotomine sandflies is of major veterinary concern in Greece. The country is endemic with particularly favourable environmental conditions for the spread of this infection. Moreover, Greece remains a popular touristic destination, and the continuous travel of pets raises concern regarding the possible dissemination of infection from endemic to non-endemic areas. Dogs are the main reservoir host, although other animal species, including humans, may also be infected. Canine leishmaniosis manifests as a visceral disease that can result in death if left untreated. Serological and molecular epizootiological studies have confirmed circulation of the parasite in Greek canine and feline populations as well as in other mammals. As a result, constant surveillance and identification of high-risk localities are necessary to establish chemoprophylactic protocols for travelling animals to safeguard animal and public health.

Wild Mesocarnivores as Reservoirs of Endoparasites Causing Important Zoonoses and Emerging Bridging Infections across Europe.

Mesocarnivores are small- or mid-sized carnivore species that display a variety of ecologies and behaviours. In Europe, wild mesocarnivores are represented by the red fox (Vulpes vulpes), the golden jackal (Canis aureus), the European wildcat (Felis silvestris), the Mustelidae of the genera Meles, Martes, Mustela, Lutra, the invasive species of raccoon dog (Nyctereutes procyonoides), raccoons (Procyon lotor), and American mink (Neogale vison). These abundant animals thrive in various habitats and often develop their activity close to human settlements. Thus, they may play an important role in the introduction, maintenance, and transmission of major parasitic zoonoses and promote bridging infections with domestic animals. Against this background, this article reports and discusses some of the most important endoparasites of wild mesocarnivores living in Europe, on the basis of their actual role as reservoirs, spreaders, or sentinels. The data derived from epizootiological studies in different European countries, and the proven or speculated implications of the detected endoparasites in human and domestic animals' health, are discussed. Through older and recent literature review, the state-of-the-art knowledge on the occurrence and prevalence of the parasites under consideration is presented, showing further, warranted investigations and the need for surveillance and vigilance.

Investigations on bovine herpesvirus 4 infections in cattle in Bulgaria

Cattle infected with BHV 4 show respiratory symptoms, gastrointestinal and postnatal genital disorders. The virus is a cofactor of bacterial infections. This paper reflects data on the prevalence of BHV 4 infections in several herds, among breeding animals and bulls from artificial insemination stations (AIS). One hundred and twenty six serum samples from bulls were investigated by MVNT and 45 (35.7%) were positive. Epizootiological and clinical studies on the prevalence of BHV 4 infections were limited to bovine farms with suspected infection with this virus. To establish seroconversion to the virus, double serum samples from 264 cattle – 165 native-born cows and 99 imported pregnant heifers were investigated by the microvirus neutralisation test (MVNT) and commercial ELISA for the detection of antibodies against BHV 4. Ninety-nine samples (37.5%) were positive in the MVNT and 110 samples (41.6%) – in ELISA. One out of the seven milk samples from cows with signs of mammary glands involvement was positive in the polymerase chain reaction (PCR) performed to detect the gB and Tk virus genes. Four of the ten whole blood samples from acutely ill animals were positive for BHV 4 DNA by PCR. The results of the present study confirmed that the BHV 4 circulated within the Bulgarian cattle population.

A Multi-Model Paradigm in Application to the Analysis of the Factors Defining the Epizootic Situation in the Communities of Non-Synanthropic Small Mammals in Ekaterinburg

The aim of the work was to rank statistical models for assessing the contribution of a number of factors that determine the epizootic situation on natural-focal infectious diseases in the communities of non-synanthropic small mammals (SM) in the forests of Ekaterinburg.Materials and methods. The SM survey was carried out for three years in the summer-autumn period. The animals were caught with snap tpaps on a standard bread bait, 9705 trap-nights were worked out. To identify infections (hemorrhagic fever with renal syndrome, tularemia, leptospirosis, yersiniosis, pseudotuberculosis), 333 SM specimens (rodents and shrews of six species) were used, randomly taken from the general sample. To determine the pathogens, the methods of enzyme immunoassay and polymerase chain reaction were used. The cumulative infection rate of small mammals with all studied natural-focal infections was evaluated. Statistical data processing was carried out from the standpoint of a multi-model approach. The selection of models was performed using the Akaike information criterion with the calculation of the sum of the weights of the models based on their full spectrum (SW).Results and discussion. Carriers of all of the mentioned above infections, except for pseudotuberculosis, have been identified in the forest parks of Ekaterinburg. According to the ranking, the model with three predictors received the highest weight: species, year, and the abundance of SM of the previous year in a particular habitat. The most significant predictors for the full spectrum of models are the year (SW=1), species (SW=0.6), abundance of animals in the current and previous year (SW=0.48). The distribution of positive samples by species of small mammals corresponded to their ranking by abundance in the community. The influence of the factors “season” (summer or autumn) and “area” (place of capture of animals) turned out to be insignificant on the scale of the studies (SW = 0.3 and 0.16, respectively). The percentage of infected samples in total for all infections varied significantly by location and year (0–60%). The possible significance of unaccounted factors is discussed: landscape features and the mode of using forest parks, dispersal of small mammals. The conclusion is made about the usefulness of the multi-model approach in the analysis of the data from epizootiological studies.

A Cross-Sectional Epizootiological Study and Risk Assessment of Foot-Related Lesions and Lameness in Intensive Dairy Sheep Farms.

Simple SummaryFoot-related lameness is one of the most significant welfare issues in farm animals. Contrary to dairy cows and meat sheep breeds, epizootiological data on foot-lesions and associated lameness in dairy sheep are scarce. In this study, data were collected from 30 representative intensive dairy sheep farms. Multivariate statistical analysis was used to produce a typology of intensive farming systems which resulted in the assignment of farms in two distinct clusters. Six hundred adult ewes were randomly selected from six flocks (three flocks per cluster) and a cross-sectional study was implemented to investigate the epizootiology and potential risk factors of foot-related lameness, foot-lesions and diseases. Ovine interdigital dermatitis and infectious footrot were the most common infectious foot diseases, while white line disease and hoof wall cracks were the most prevalent non-infectious lesions. Infectious footrot was the main cause of lameness and increased with age, whereas body condition score was associated with increased prevalence of ovine interdigital dermatitis. Comparisons between the clusters regarding foot-related lameness, foot-diseases and lesions at the animal, the limb, and the hoof level are presented, and relevant literature, mechanisms, hypotheses, and challenges of the field are discussed.Foot-related lameness, foot-diseases and lesions are emerging issues in dairy sheep; however, relevant epizootiological studies are scarce, and risk factors have not been elucidated. The objectives of this cross-sectional study were (i) to address this dearth of knowledge by investigating the epizootiology of lameness-related foot-lesions and diseases, and (ii) to assess the impact of potential risk factors on foot health, in intensive dairy sheep farms. Thirty farms were assigned in two representative clusters using a multivariate statistical analysis. Three farms per cluster and 100 multiparous milking ewes per farm (total n = 600) were selected and enrolled in the study. Foot-related lameness, ovine interdigital dermatitis (OID), infectious footrot (IFR), white line disease, hoof wall cracks, as well as health and welfare traits were recorded. Overall prevalence of foot-related lameness was 9.0% and was primarily associated with IFR; however, additional infectious and non-infectious foot diseases and lesions also contributed. Among infectious foot diseases, OID was the most prevalent (21.3%) followed by IFR (8.0%); WLD and hoof wall cracks were the most prevalent non-infectious foot-lesions (37.7% and 15.3%, respectively). IFR and OID prevalence increased with age (p < 0.05) and BCS (p < 0.01), respectively, suggesting that host-related factors and husbandry practices are important determinants of its occurrence.

Chlamydiosis of dogs and cats in modern cities

The aim of the research was to conduct an in-depth analysis of the investigation of chlamydial infections occurred in cats and dogs in Kyiv during the last 10 years. The article includes three main directions of investigation: 1) The analysis of the epizootic situation with chlamydiosis; 2) Microbiological investigation and 3) Serological monitoring. The clinical and epizootiological studies of chlamydiosis of dogs and cats have been looked into, with the focus on differences and similarities in age and sex of diseased animals. We have investigated 3334 animals (1351 dogs and 1983 cats), including 721 animals (107 dogs and 614 cats) with the manifestation of clinical signs specific to chlamydia. During the investigation 11 isolates of Chlamydia spp. were obtained from the infected animals. Additionally, immune and biological peculiarities have been analyzed. Due to serological monitoring within the epizootiological uncontrolled experiment, a satisfactory level of protection of cats (63%) vaccinated against chlamydiosis has been reached, as well as the possibility of the persistence of the pathogen in unvaccinated animals (9%).

Modern Epizootiological-Epidemiological Situation on Natural-Focal Infections in the Resort City of Sochi

Objective - analysis of the epizootic-epidemiological situation on natural-focal infections in the resort city of Sochi. Materials and methods . We used the reports on and results of annual epizootiological monitoring of the territory of Sochi, presented by the Rospotrebnadzor Administration in the Krasnodar Territory, Center of Hygiene and Epidemiology in the Krasnodar Territory, Black Sea Plague Control Station, Sochi Anti-Plague Department of the Black Sea Plague Control Station, Stavropol Research Anti-Plague Institute. Results and discussion . The paper provides the analysis of the incidence among population, the results of epizootiological monitoring and molecular-genetic studies of isolates collected in the territory of the resort city of Sochi during 2014-2018. The most significant natural-focal infections in this region are: hemorrhagic fever with renal syndrome, Lyme disease, intestinal yersiniosis, leptospirosis. It was established that the natural foci of the infections studied in the territory of the resort city of Sochi are combined ones, which increases their epidemic importance and imposes requirements for a more in-depth survey of the territories. Thus, the current epizootiological-epidemiological situation on natural-focal infections in the region of the resort city of Sochi is characterized by the preservation of the activity of natural foci and indicates the need for their continuous monitoring, as well as implementation of a set of regulated preventive measures.

Standard and molecular methods in the diagnostics of infections caused by equine herpesviruses 1 and 4

Background. Equine herpesvirus type 1 (EHV-1) is responsible for respiratory disease in young animals, abortion in pregnant mares and neurological disease, whilst equine herpesvirus 4 (EHV-4) is mainly the causative agent of respiratory disorders and rarely causes abortion. These viruses are considered as one of the most clinically and economically important pathogens of horses and can be detected in a range of tissues. Scope and Approach. Serological methods are used to detect the presence and titre of specific antibodies to EHV-1 and EHV-4 in the sera of examined horses and are useful in epizootiological studies. Commercially available ELISA kits are able to differentiate specific EHV-1 and EHV-4 antibodies. EHV-1 and EHV-4 can both be isolated using susceptible cells such as primary horse cell cultures and other non-equine cells with visible cytopathic effect. Since standard diagnostic methods can be time consuming and arduous, the scope of many studies has been to develop and confirm the sensitivity and specificity of molecular diagnostic methods. Key Findings and Conclusions. Polymerase chain reaction (PCR) has proved to be a good screening method for the presence of latent infections of horses caused by these viruses, also making possible the rapid identification and differentiation of EHV-1 and- EHV-4 in the examined samples. Real-time PCR is a sensitive, specific and quantitative method that enables the determination of viral kinetics in infected horses. Genome sequencing can be used to discover mutations in the genomes of EHV-1 and EHV-4 as well as to track the spread of their different strains globally.

The results of epizootiological monitoring of the natural foci for leptospirosis in Armenia

Purpose: There are permanent natural foci for leptospirosis in all regions of the Republic of Armenia. Epizootiological monitoring of natural and agricultural foci is necessary to prevent human infection. The Laboratory of Particularly Dangerous Infections of NCDCP performs such monitoring, taking into consideration epidemiological and epizootic condition of these areas including the number of rodents. Methods & Materials: The highly sensitive micro-agglutination reaction (MAR) of leptospira is used to detect infection in rodents. It allows both determination of the presence of antibodies and serotyping of the agent, thus allowing the opportunity for performing a targeted epidemiological search of the infection focus. MAR serotyping is enabled by the set of 12 serotypes of leptospira cultures grown for 6-10 days. The “squeezed drop” reaction is used to study samples of animal blood dried on filter paper. Results: From 2006-2015 blood samples from two to three thousand rodents captured from all the Marzes of Armenia were examined with MAR. The number of rodent infections was reported by year. The rates of rodent positivity for leptospirosis in the MAR assay was 4% for 2006-2007, 9% for 2008-2009, 5-6% for 2009-2013, 10% for 2013 and 6-8% since 2013. All twelve serotypes were observed during the study period with three serotypes being particularly high: L. autumnalis (15%), L. hebdomadis (12%) and L. icterrohaemorragiae (9%). Conclusion: These studies have helped to characterize the natural foci of leptospirosis in Armenia which is a potential threat for humans. Continued, regular epizootiological studies are necessary to monitor this situation.

Rickettsia species in fleas collected from small mammals in Slovakia.

Epidemiological and epizootiological studies of Rickettsia felis and other Rickettsia spp. are very important, because their natural cycle has not yet been established completely. In total, 315 fleas (Siphonaptera) of 11 species of Ceratophyllidae, Hystrichopsyllidae and Leptopsyllidae families were tested for the presence of Rickettsia species and Coxiella burnetii with conventional and specific quantitative real-time PCR assays. Fleas were collected from five rodent hosts (Myodes glareolus, Apodemus flavicollis, Apodemus agrarius, Microtus subterraneus, Microtus arvalis) and three shrew species (Sorex araneus, Neomys fodiens, Crocidura suaveolens) captured in Eastern and Southern Slovakia. Overall, Rickettsia spp. was found in 10.8% (34/315) of the tested fleas of Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus uncinatus and Nosopsyllus fasciatus species. Infected fleas were coming from A. flavicollis, A. agrarius, and M. glareolus captured in Eastern Slovakia. C. burnetii was not found in any fleas. R. felis, Rickettsia helvetica, unidentified Rickettsia, and rickettsial endosymbionts were identified in fleas infesting small mammals in the Košice region, Eastern Slovakia. This study is the first report of R. felis infection in C. solutus male flea collected from A. agrarius in Slovakia.

Expanding the knowledge of the geographic distribution of Trypanosoma cruzi TcII and TcV/TcVI genotypes in the Brazilian Amazon.

Trypanosoma cruzi infection is a complex sylvatic enzooty involving a wide range of animal species. Six discrete typing units (DTUs) of T. cruzi, named TcI to TcVI, are currently recognized. One unanswered question concerning the epidemiology of T. cruzi is the distribution pattern of TcII and hybrid DTUs in nature, including their virtual absence in the Brazilian Amazon, the current endemic area of Chagas disease in Brazil. Herein, we characterized biological samples that were collected in previous epizootiological studies carried out in the Amazon Basin in Brazil. We performed T. cruzi genotyping using four polymorphic genes to identify T. cruzi DTUs: mini-exon, 1f8, histone 3 and gp72. This analysis was conducted in the following biological samples: (i) two T. cruzi isolates obtained by culturing of stools from the triatomine species Rhodnius picttipes and (ii) five serum samples from dogs in which trypomastigotes were observed during fresh blood examination. We report for the first time the presence of TcII and hybrid DTUs (TcV/TcVI) in the Amazon region in mixed infections with TcI. Furthermore, sequencing of the constitutive gene, gp72, demonstrated diversity in TcII even within the same forest fragment. These data show that TcII is distributed in the five main Brazilian biomes and is likely more prevalent than currently described. It is very probable that there is no biological or ecological barrier to the transmission and establishment of any DTU in any biome in Brazil.

Stability of the WSSV ORF94 VNTR genotype marker during passage in marine shrimp, freshwater crayfish and freshwater prawns.

The white spot syndrome virus (WSSV) genome contains 3 variable number tandem repeat (VNTR) regions, located in open reading frame (ORF) 75, ORF94 and ORF125, which have been employed for molecular epizootiological studies. A previous report suggested that the ORF 94 VNTR is highly unstable, varying in the number of tandem repeats during single passages from shrimp to other crustaceans. As such rapid variations would have profound implications for the interpretation of molecular epizootiological data, we re-examined the stability of the ORF94 VNTR. Two WSSV isolates with different ORF94 VNTR genotypes (TRS5 and TRS7) were obtained from disease outbreaks in farmed black tiger shrimp Penaeus monodon in Indonesia. High titre stocks of each virus were produced by injection in specific pathogen-free (SPF) Pacific white shrimp Litopenaeus vannamei with filtered infected tissue extracts, and the genotypes were confirmed. Each stock (macerated tissue) was then used to feed SPF Pacific white shrimp, freshwater crayfish (Cherax sp.) and freshwater prawns Macrobrachium rosenbergii through 3 successive passages involving alternative hosts at each level. Taqman real-time PCR was conducted on samples from each group to confirm infection and quantify viral genetic loads. ORF94 VNTR genotype analysis conducted on samples from each of the 43 passage groups indicated no variations in the VNTR number in either genotype TRS5 or genotype TRS7. This finding is contrary to the previous report and suggests that ORF94 VNTR are stable during multiple passages in these crustaceans.

Epizootiological-and-Epidemical Situation on Tularemia in the South of Far East Region during the Period of River Floods

Carried out were epizootiological studies of the flooded areas of the Amur Region, the Khabarovsk territory, and the Jewish autonomous region in order to investigate the situation on tularemia in view of the river floods in August-September, 2013. Involved were specialized anti-epidemic teams from Irkutsk Research Anti-Plague Institute for works at the site of emergency. Therewith, analysis of the data of the epizootiological examination of the territories obtained in cooperation with specialists from the Rospotrebnadzor local Centers of Hygiene and Epidemiology, and results of laboratory investigations with application of bacteriological, immu­no­bio­logical and molecular-genetic methods indicated insignificant epizootic and epidemic activity of the natural tularemia foci. Given is the conclusion on epizootiological-epidemiological condition for tularemia in the flooded areas of the Amur River region and a short-term epizootiological forecast for 2013-2014, as well as recommendations concerning stabilization and improvement of epidemiological conditions in the region.

Q FEVER EPIDEMIOLOGY AND CONTROL IN DOMESTIC ANIMALS

The significance of each domestic animal in the epidemiology of Q-fever is different in various regions and it depends on the number of animals, level of infection, herd size, type of breeding and the conditions of hygiene. Epizootiological studies in our country show greater prevalence in sheep, than in cattle. Q-fever is maintained in Vojvodina in endemo-epidemic form. In Q-fever management programs for control of in sheep and cattle, serological examination and vaccination of the animals is recommended. Efficiency of the application of these measures should be conducted by applying recommended serological tests and detection of causative agent should be done by PCR method. A study on the comparative examination of efficiency, of different vaccination protocols has not yet been conducted. This would refer primarily to the duration of vaccination program, animal categories that are supposed to be vaccinated and timing for vaccination. A significant decrease in the level of infection was found after vaccination during the first years upon application of vaccination program. When vaccination in heifers was done before pregnancy with vaccines containing C.burnetii phase I strains, it was five times less likely that the infection would occur. Vaccination of cows with chronic infection prevents shedding of riketsia via milk, regardless whether the shedding is constant or intermittent. Vaccination represents a new concept of suppression of this zoonozes in the terms of human protection, and also in the terms of creating areas free from Q-fever in endemic regions. General preventive measures applied in the case of Q-fever infection are: movement restriction, separation of animals, restriction of milk and wool, adequate hygiene, using the protective clothing, desinfection of equipement and vechicles, removing of placenta particles, removing of manure, quarantine after calving and lambing and not use common grazing. People proffesionally exposed to the risk from infection should be educated about the disease.

Life cycle of Renylaima capensis, a brachylaimid trematode of shrews and slugs in South Africa: two-host and three-host transmission modalities suggested by epizootiology and DNA sequencing

BackgroundThe life cycle of the brachylaimid trematode species Renylaima capensis, infecting the urinary system of the shrew Myosorex varius (Mammalia: Soricidae: Crocidosoricinae) in the Hottentots Holland Nature Reserve, South Africa, has been elucidated by a study of its larval stages, epizootiological data in local snails and mammals during a 34-year period, and its verification with mtDNA sequencing.MethodsParasites obtained from dissected animals were mounted in microscope slides for the parasitological study and measured according to standardized methods. The mitochondrial DNA cox1 gene was sequenced by the dideoxy chain-termination method.ResultsThe slugs Ariostralis nebulosa and Ariopelta capensis (Gastropoda: Arionidae) act as specific first and second intermediate hosts, respectively. Branched sporocysts massively develop in A. nebulosa. Intrasporocystic mature cercariae show differentiated gonads, male terminal duct, ventral genital pore, and usually no tail, opposite to Brachylaimidae in which mature cercariae show a germinal primordium and small tail. Unencysted metacercariae, usually brevicaudate, infect the kidney of A. capensis and differ from mature cercariae by only a slightly greater size. The final microhabitats are the kidneys and ureters of the shrews, kidney pelvis and calyces in light infections and also kidney medulla and cortex in heavy infections. Sporocysts, cercariae, metacercariae and adults proved to belong to R. capensis by analysis of a 437-bp-long cox1 fragment, which was identical except for three mutations in metacercariae, of which only one silent. Epizootiological studies showed usual sporocyst infection in A. nebulosa and very rare metacercarial infection in A. capensis, which does not agree with high prevalences and intensities in the shrews.ConclusionsThe presence of monotesticular adult forms and larval prevalences and intensities observed suggest that R. capensis may use two transmission strategies, a two-host life cycle by predation of A. nebulosa harbouring intrasporocystic cercariae may be the normal pattern, whereas a second mollusc host is just starting to be introduced. In shrews, a tissue-traversing, intraorganic migration followed by an interorganic migration to reach and penetrate the outer surface of either of both kidneys should occur. For first slug infection, the fluke takes advantage of the phenomenon that M. varius always urinate during defaecation. Consequently, in Brachylaimidae, the second intermediate mollusc host should evolutionarily be seen as a last addition to the cycle and their present adult stage microhabitat restricted to digestive tract and related organs as a loss of the tissue-traversing capacity of the metacercaria.

Molecular tools for the detection and identification of Ichthyobodo spp. (Kinetoplastida), important fish parasites

Ichthyobodo spp. are ectoparasitic flagellates of fish that may cause disease (ichthyobodosis), a common problem affecting the aquaculture industry worldwide. Ichthyobodosis in farmed fish is often associated with a range of other infectious agents and diagnosis in for example gill disease may be difficult. Sensitive and effective methods for detection and identification of Ichthyobodo spp. are needed to aid diagnosis of ichthyobodosis and epizootiological studies on Ichthyobodo spp. We have designed a specific quantitative real-time PCR assay targeting SSU rDNA for the detection of Ichthyobodo spp. infections. Also, several novel primer sets are presented for use in identification of Ichthyobodo spp. through PCR and sequencing. These PCR methods have been optimized and tested on samples from wild caught and farmed fish from different geographical areas in Norway. The real-time PCR assay has been tested for sensitivity and efficiency, and we present data demonstrating its use for absolute quantification of Ichthyobodo salmonis in tissue samples through RT-qPCR and qPCR. We demonstrate the use of the described set of molecular tools for the detection and sequencing of Ichthyobodo spp. from farmed and wild fish, and also show that they may aid the discovery of new Ichthyobodo species. The detection of light Ichthyobodo spp. infections through microscopy is time consuming and less sensitive compared to PCR methods. Initial real-time PCR testing and subsequent sequencing of positive samples is a powerful method that will increase diagnostic precision, aid carrier detection and promote species discoveries in the Ichthyobodonidae. Our preliminary observations indicate a high Ichthyobodo spp. diversity.

Occurrence of Giardia duodenalis infection in chinchillas (Chincilla lanigera) from Italian breeding facilities

The present work investigated the occurrence of Giardia infection in Chinchilla lanigera reared in three Italian breeding facilities and determined their role as potential zoonotic reservoir. One hundred and four fecal samples were tested for the presence of Giardia spp. cysts using a Direct Fluorescent Assay (DFA). A high positivity rate (39.4%) was found despite all animals were asymptomatic at the time of sampling. Thirty-one positive samples were genetically characterized by sequence analysis of the ITS1–5.8S–ITS2 region of the Giardia ribosomal DNA. Assemblages B (29 isolates) and C (two isolates) were identified. These results showed that Giardia infection can be common in chinchillas, thus spurring further molecular epizootiological studies of the infection to assess the zoonotic potential or host specificity of their isolates, to determine the source of infections, to identify the routes of transmission, and to control the infection among animal populations.

Characteristics of Disease Spectrum in relation to Species, Serogroups, and Adhesion Ability of Motile Aeromonads in Fish

An attempt was made to delineate the relationship between of Aeromonas species and/or serogroups and specific disease symptoms in common carp Cyprinus carpio L. and rainbow trout Oncorhynchus mykiss Walbaum. The adhesion of Aeromonas strains to various tissues in relation to disease spectrum was also tested. All strains of A. hydrophila caused skin ulcers as well as septicaemia in both carp and trout while the other strains were able to cause only skin ulcers or some specific internal lesions with or without septicaemia depending on which species and/or serogroup they represented. Disease symptoms depended also on fish species. It was found that adhesion intensity of Aeromonas strains tested was significantly higher to tissues, which were susceptible to infection with these strains. The results indicate that adhesion to various cells of the fish organism is principal marker to detect virulent Aeromonas strains. The findings presented in this study may be helpful in the appraisal of aeromonads disease risk and kind of the infection in particular fish farms by epizootiological studies or/and during routine fish examinations. They will also be useful to improve and facilitate diagnosis of bacterial fish disease.

Sphaerothecum destruens pathology in cyprinids

Sphaerothecum destruens is a significant intracellular parasite of fish which has caused disease and mortalities in cultured north American Chinook salmon Oncorhynchus tshawytscha and Atlantic salmon Salmo salar. Several hosts for S. destruens have been identified within the Salmonidae family, and the histopathology of the infection can differ between hosts. Recently, S. destruens has been associated with the most invasive cyprinid species in Europe, topmouth gudgeon Pseudorasbora parva. Accurate disease identification based on thorough descriptions of clinical signs and histopathology in this new range of hosts is thus paramount to support further epizootiological studies. In this study, the associated histopathology of S. destruens infection is described along with its pathogenesis in the endangered cyprinid sunbleak Leucaspius delineatus. Histological examination of 100 L. delineatus in a wild population in the south of England revealed the presence of S. destruens infections, with a prevalence of 5% with S. destruens, suggesting an over-dispersed distribution within the L. delineatus sample. Clinical signs of the infection were absent, but histological examination revealed the presence of both disseminated and nodular lesions in several organs.