Domenico Otranto

Ticks and tick-borne diseases: a One Health perspective

Tick-borne diseases are common occurrences in both the medical and veterinary clinical settings. In addition to the constraints related to their diagnosis and clinical management, the control and prevention of these diseases is often difficult, because it requires the disruption of a complex transmission chain, involving vertebrate hosts and ticks, which interact in a constantly changing environment. We provide a contemporary review of representative tick-borne diseases of humans and discuss aspects linked to their medical relevance worldwide. Finally, we emphasize the importance of a One Health approach to tick-borne diseases, calling physicians and veterinarians to unify their efforts in the management of these diseases, several of which are zoonoses.

On a Cercopithifilaria sp. transmitted by Rhipicephalus sanguineus: a neglected, but widespread filarioid of dogs

BackgroundThis study was aimed at investigating the distribution of a Cercopithifilaria sp. sensu Otranto et al., 2011 with dermal microfilariae recently identified in a dog from Sicily (Italy). A large epidemiological survey was conducted by examining skin samples (n = 917) and ticks (n = 890) collected from dogs at different time points in Italy, central Spain and eastern Greece.ResultsThe overall prevalence of Cercopithifilaria sp. in the sampled animal populations was 13.9% and 10.5% by microscopy of skin sediments and by PCR on skin samples, respectively. Up to 21.6% and 45.5% of dogs in Spain were positive by microscopical examination and by PCR. Cumulative incidence rates ranging from 7.7% to 13.9% were estimated in dogs from two sites in Italy. A low level of agreement between the two diagnostic tests (microscopical examination and PCR) was recorded in sites where samples were processed in parallel. Infestation rate as determined by tick dissection (from 5.2% to 16.7%) was higher than that detected by PCR (from 0% to 3.9%); tick infestation was significantly associated with Cercopithifilaria sp. infestation in dogs from two out of four sites. Developing larvae found in ticks were morphometrically studied and as many as 1469 larvae were found in a single tick.ConclusionsOur data suggest that, in addition to the most common species of filarioids known to infest dogs (i.e., Dirofilaria immitis, Dirofilaria repens and Acanthocheilonema reconditum), Cercopithifilaria sp. with dermal microfilariae should be considered due to its widespread distribution in southern Europe and high frequency in tick-exposed dogs.

Single-strand conformation polymorphism (SSCP) for the analysis of genetic variation

The accurate analysis of genetic variation has major implications in many areas of biomedical research, including the identification of infectious agents (such as parasites), the diagnosis of infections, and the detection of unknown or known disease-causing mutations. Mutation scanning methods, including PCR-coupled single-strand conformation polymorphism (SSCP), have significant advantages over many other nucleic acid techniques for the accurate analysis of allelic and mutational sequence variation. The present protocol describes the SSCP method of analysis, including all steps from the small-scale isolation of genomic DNA and PCR amplification of target sequences, through to the gel-based separation of amplicons and scanning for mutations by SSCP (either by the analysis of radiolabeled amplicons in mutation detection enhancement (MDE) gels or by non-isotopic SSCP using precast GMA gels). The subsequent sequence analysis of polymorphic bands isolated from gels is also detailed. The SSCP protocol can readily detect point mutations for amplicon sizes of up to 450–500 bp, and usually takes 1–2 days to carry out. This user-friendly, low-cost, potentially high-throughput platform has demonstrated the utility to study a wide range of pathogens and diseases, and has the potential to be applied to any gene of any organism.

Managing canine vector-borne diseases of zoonotic concern: part two

Despite recent achievements in scientific knowledge related to canine vector-borne diseases (CVBDs) of zoonotic concern, their management is still impaired by several neglected issues related to accurate diagnosis and effective treatment of both single and co-infections. A better understanding of the pathogenesis and the progression of clinical, hematological and biochemical abnormalities of CVBDs will be important in choosing appropriate diagnostic tests and in establishing the best strategies for treatment and control. Nonetheless, the diagnosis and control of zoonotic infections in clinically healthy dogs remain challenging. This review discusses the crucial aspects involved in the diagnosis, treatment, prevention and control of CVBDs of zoonotic concern.

Morphological and genetic diversity of Rhipicephalus sanguineus sensu lato from the New and Old Worlds.

BackgroundThe taxonomic status of the brown dog tick (Rhipicephalus sanguineus sensu stricto), which has long been regarded as the most widespread tick worldwide and a vector of many pathogens to dogs and humans, is currently under dispute.MethodsWe conducted a comprehensive morphological and genetic study of 278 representative specimens, which belonged to different species (i.e., Rhipicephalus bursa, R. guilhoni, R. microplus, R. muhsamae, R. pusillus, R. sanguineus sensu lato, and R. turanicus) collected from Europe, Asia, Americas, and Oceania. After detailed morphological examination, ticks were molecularly processed for the analysis of partial mitochondrial (16S rDNA, 12S rDNA, and cox 1) gene sequences.ResultsIn addition to R. sanguineus s.l. and R. turanicus, three different operational taxonomic units (namely, R. sp. I, R. sp. II, and R. sp. III) were found on dogs. These operational taxonomical units were morphologically and genetically different from R. sanguineus s.l. and R. turanicus. Ticks identified as R. sanguineus s.l., which corresponds to the so-called “tropical species” (=northern lineage), were found in all continents and genetically it represents a sister group of R. guilhoni. R. turanicus was found on a wide range of hosts in Italy and also on dogs in Greece.ConclusionsThe tropical species and the temperate species (=southern lineage) are paraphyletic groups. The occurrence of R. turanicus in the Mediterranean region is confirmed. A consensual re-description of R. sanguineus s.s. and R. turanicus will be necessary to solve the taxonomic problems within the so-called R. sanguineus group.

Canine and feline vector-borne diseases in Italy: current situation and perspectives

In Italy, dogs and cats are at risk of becoming infected by different vector-borne pathogens, including protozoa, bacteria, and helminths. Ticks, fleas, phlebotomine sand flies, and mosquitoes are recognized vectors of pathogens affecting cats and dogs, some of which (e.g., Anaplasma phagocytophilum, Borrelia burgdorferi, Dipylidium caninum, Leishmania infantum, Dirofilaria immitis, and Dirofilaria repens) are of zoonotic concern. Recent studies have highlighted the potential of fleas as vectors of pathogens of zoonotic relevance (e.g., Rickettsia felis) in this country. While some arthropod vectors (e.g., ticks and fleas) are present in certain Italian regions throughout the year, others (e.g., phlebotomine sand flies) are most active during the summer season. Accordingly, control strategies, such as those relying on the systematic use of acaricides and insecticides, should be planned on the basis of the ecology of both vectors and pathogens in different geographical areas in order to improve their effectiveness in reducing the risk of infection by vector-borne pathogens. This article reviews the current situation and perspectives of canine and feline vector-borne diseases in Italy.

Anthelmintic resistance in cyathostomin populations from horse yards in Italy, United Kingdom and Germany.

BackgroundA large survey was carried out in 2008 in Europe to evaluate the efficacy of fenbendazole (FBZ), pyrantel (PYR), ivermectin (IVM) and moxidectin (MOX), i.e. the major anthelmintic molecules used in current practice against cyathostomins affecting horses. A total of 102 yards and 1704 horses was studied in three countries: 60 yards and 988 horses from Italy, 22 and 396 from the UK, 20 and 320 from Germany. The survey consisted of Faecal Egg Count Reduction Tests (FECRTs) with a faecal egg count reduction (FECR) categorization of (I) resistance present if FECR <90% and the lower 95% confidence limit (LCL) <90%, (II) resistance suspected if FECR ≥ 90% and/or LCL <90% and (III) no resistance if FECR ≥ 90% and LCL >90%. The calculation of FECR data was performed employing bootstrap analysis of group arithmetic means.ResultsThe testing of FBZ on a total of 80 yards resulted in resistance present on more than 80% of the UK and German yards and on significantly fewer in Italy, i.e. in 38% (p < 0.01). PYR, IVM and MOX were tested on a total of 102 yards. For PYR resistance present was found in 25% of the yards with no significant differences between countries. For IVM resistance present was encountered in one Italian and two UK yards (3%), resistance present to MOX was not found in any yard in any country.ConclusionThe results indicate that single and/or multiple drug resistance in equine cyathostomins is present in the three countries, is widespread particularly for FBZ and/or PYR and in one UK yard multiple resistance present was detected to FBZ, PYR and IVM. Macrocylic lactones proved to be the most effective drugs, with some evidence of resistance to IVM and highest activity of MOX, despite a single case of reduced efficacy in Germany. These data call for the development and implementation, among practitioners, owners and managers, of further plans to reduce the expansion of the anthelmintic resistant populations and to use those anthelmintics that remain effective in a manner that preserves their efficacy as long as possible.

Canine leishmaniosis in the Old and New Worlds: unveiled similarities and differences

Canine leishmaniosis is a potentially life-threatening disease which is spreading geographically in the Old and New Worlds, where different diagnostic procedures, treatments, and control strategies are currently in place. This Opinion article outlines the similarities and differences between canine leishmaniosis in the Old and New Worlds, with emphasis on South America and Europe. Finally, it calls the attention of veterinary and public health authorities to standardize and improve practices for diagnosing, treating, and preventing the disease.

Occurrence of Yeasts in Cloacae of Migratory Birds

Several species of yeast have been reported as pathogens in humans based on increases in immunodeficiency syndromes and as a result of immunosuppressant chemotherapy in cancer treatment. Domestic and wild birds are known to act as carriers of human pathogenic fungi. To gain additional information on the yeasts present in the cloacae of some species of migratory birds, 421 wild birds (24.39% out of 1726 birds caught in Romania, Hungary and Bulgaria) were sampled with the permission of the local judicial authority. The state of conservation of the birds (i.e. post-mortem alterations, colour of the mucosae etc.), along with their age and sex were determined. Samples were collected directly from the cloacae and cultured, and colonies were identified in each positive sample. Yeasts were isolated from 15.7% of the animals sampled, with the highest percentage found in coots (Fulica atra −58.8%) and the lowest in quails (Coturnix coturnix −1.7%). A total of 131 isolates belonging to 15 species of yeast were identified. Rhodotorula rubra was the yeast with the highest number of isolates (28.2%), followed by Cryptococcus albidus (18.4%), Candida albicans (9.2%), Trichosporon cutaneum (8.4%), Candida guilliermondii (6.1%), Candida tropicalis (6.1%) and other species. The present study represents the first survey on the occurrence of yeasts in the cloacae of migratory birds. The prevalence and species of yeasts isolated is discussed on the basis of the ecology, diet, and habitat of the birds.

Role of birds of prey as carriers and spreaders of Cryptococcus neoformans and other zoonotic yeasts

In the last 20 years, cases of human cryptococcosis, have increased in immunocompromised patients. In several instances, the cases have been associated with the exposure of the patients to bird droppings. In order to investigate birds of prey as potential carriers and spreaders of Cryptococcus neoformans and other yeasts of importance in human infections, 182 swab samples were collected from the cloacae of several species of birds of prey (Group I) and 32 faecal samples from aviaries in which the birds were housed (Group II). Samples were also taken from digestive tract of 60 dead birds (Group III). A total of 454 samples were cultured from which 215 colonies of yeastlike fungi were recovered and identified. Cryptococcusneoformans var. grubii was isolated from three cloacae samples (4.8%) collected from Falco tinnunculus and from one sample (3.1%) obtained from Buteo buteo, as well as from samples collected at the aviaries in which these birds were kept. Overall, 18 samples (9.9%) from Group I, 13 (40.6%) from Group II, 12 crops (20%), three proventriculi (5%) and 12 cloacae (20%) from Group III yielded positive cultures for yeasts. The results indicate that birds of prey and in particular, F. tinnunculus and B. buteo, may act as carriers and spreaders of C. neoformans and other zoonotic yeasts.