Development of a PCR technique specific for Demodex injai in biological specimens

The identification of Demodex injai as a second Demodex species of dog opened new questions and challenges in the understanding on the Demodex–host relationships. In this paper, we describe the development of a conventional PCR technique based on published genome sequences of D. injai from GenBank that specifically detects DNA from D. injai. This technique amplifies a 238-bp fragment corresponding to a region of the mitochondrial 16S rDNA of D. injai. The PCR was positive in DNA samples obtained from mites identified morphologically as D. injai, which served as positive controls, as well as in samples from three cases of demodicosis associated with proliferation of mites identified as D. injai. Furthermore, the PCR was positive in 2 out of 19 healthy dogs. Samples of Demodex canis and Demodex folliculorum were consistently negative. Skin samples from seven dogs with generalized demodicosis caused by D. canis were all negative in the D. injai-specific PCR, demonstrating that in generalized canine demodicosis, mite proliferation is species-specific. This technique can be a useful tool in the diagnosis and in epidemiologic and pathogenic studies.     

Phylogenetic analysis of Demodex caprae based on mitochondrial 16S rDNA sequence

Demodex caprae infests the hair follicles and sebaceous glands of goats worldwide, which not only seriously impairs goat farming, but also causes a big economic loss. However, there are few reports on the DNA level of D. caprae. To reveal the taxonomic position of D. caprae within the genus Demodex, the present study conducted phylogenetic analysis of D. caprae based on mt16S rDNA sequence data. D. caprae adults and eggs were obtained from a skin nodule of the goat suffering demodicidosis. The mt16S rDNA sequences of individual mite were amplified using specific primers, and then cloned, sequenced, and aligned. The sequence divergence, genetic distance, and transition/transversion rate were computed, and the phylogenetic trees in Demodex were reconstructed. Results revealed the 339-bp partial sequences of six D. caprae isolates were obtained, and the sequence identity was 100 % among isolates. The pairwise divergences between D. caprae and Demodex canis or Demodex folliculorum or Demodex brevis were 22.2–24.0 %, 24.0–24.9 %, and 22.9–23.2 %, respectively. The corresponding average genetic distances were 2.840, 2.926, and 2.665, and the average transition/transversion rates were 0.70, 0.55, and 0.54, respectively. The divergences, genetic distances, and transition/transversion rates of D. caprae versus the other three species all reached interspecies level. The five phylogenetic trees all presented that D. caprae clustered with D. brevis first, and then with D. canis, D. folliculorum, and Demodex injai in sequence. In conclusion, D. caprae is an independent species, and it is closer to D. brevis than to D. canis, D. folliculorum, or D. injai.     

Molecular identification and phylogenetic study of Demodex caprae

The DNA barcode has been widely used in species identification and phylogenetic analysis since 2003, but there have been no reports in Demodex. In this study, to obtain an appropriate DNA barcode for Demodex, molecular identification of Demodex caprae based on mitochondrial cox1 was conducted. Firstly, individual adults and eggs of D. caprae were obtained for genomic DNA (gDNA) extraction; Secondly, mitochondrial cox1 fragment was amplified, cloned, and sequenced; Thirdly, cox1 fragments of D. caprae were aligned with those of other Demodex retrieved from GenBank; Finally, the intra- and inter-specific divergences were computed and the phylogenetic trees were reconstructed to analyze phylogenetic relationship in Demodex. Results obtained from seven 429-bp fragments of D. caprae showed that sequence identities were above 99.1 % among three adults and four eggs. The intraspecific divergences in D. caprae, Demodex folliculorum, Demodex brevis, and Demodex canis were 0.0–0.9, 0.5–0.9, 0.0–0.2, and 0.0–0.5 %, respectively, while the interspecific divergences between D. caprae and D. folliculorum, D. canis, and D. brevis were 20.3–20.9, 21.8–23.0, and 25.0–25.3, respectively. The interspecific divergences were 10 times higher than intraspecific ones, indicating considerable barcoding gap. Furthermore, the phylogenetic trees showed that four Demodex species gathered separately, representing independent species; and Demodex folliculorum gathered with canine Demodex, D. caprae, and D. brevis in sequence. In conclusion, the selected 429-bp mitochondrial cox1 gene is an appropriate DNA barcode for molecular classification, identification, and phylogenetic analysis of Demodex. D. caprae is an independent species and D. folliculorum is closer to D. canis than to D. caprae or D. brevis.     

Molecular identification of four phenotypes of human Demodex mites (Acari: Demodicidae) based on mitochondrial 16S rDNA

Classification of Demodex mites has long depended on hosts and morphological characteristics. However, the fact that two species coexist in the same host and phenotype is easily influenced by environment causes difficulty and indeterminacy in traditional classification. Genotype, which directly reflects the molecular structure characteristics, is relatively stable. In this study, species identification of four phenotypes of human Demodex mites was conducted. Mites were morphologically classified into four phenotypes: long- and short-bodied Demodex folliculorum with finger-like terminus and Demodex brevis with finger- or cone-like terminus. The mitochondrial 16S ribosomal DNA (rDNA) fragment of individual mite was amplified, cloned, sequenced, and aligned. Sequence divergences, genetic distances, transition/transversion rates, and phylogenetic trees were analyzed. The results demonstrated that the 16S rDNA sequence of three phenotypes with finger-like terminus was 337 bp, and that of phenotype with cone-like terminus was 342 bp. The divergences, genetic distances, and transition/transversion rates among the three phenotypes with finger-like terminus were 0.0–2.7 %, 0.000–0.029, and 5.0–7/0 (5/1–7/0), respectively, indicating an intraspecific variation. Yet, those between these three phenotypes and the one with cone-like terminus were 21.6–22.8 %, 2.510–2.589, and 0.47–0.59 (22/47–27/46), respectively, suggesting an interspecific variation. The five phylogenetic trees showed that the three phenotypes with finger-like terminus clustered into one branch, while the phenotype with cone-like terminus clustered into another. In conclusion, terminus is a major morphological characteristic for the identification of human Demodex species. The three phenotypes with finger-like terminus belong to D. folliculorum, while the phenotype with cone-like terminus belongs to D. brevis. Molecular identification can verify and replenish morphological identification.     

The effect of temperature on the viability of <Emphasis Type="Italic">Demodex folliculorum</Emphasis> and <Emphasis Type="Italic">Demodex brevis</Emphasis>

Demodex folliculorum and Demodex brevis are obligatory parasites of the pilosebaceous unit in humans and are cosmopolitan in terms of their distribution. This study was conducted to explore the effect of temperature on the viability of D. folliculorum and D. brevis. Both types of parasites were collected with the cellophane tape method, then randomly grouped and placed into separate moist cabinets. They were divided into 15 groups and exposed to experimental temperatures ranging from −15°C to 60°C. Curve diagrams and scatter plots on the relationship between temperature and the corresponding survival time were drawn and analyzed. It is demonstrated that temperature has a tremendous influence on the viability of D. folliculorum and D. brevis. Survival time and temperature are inversely correlated in the temperature range of 5–37°C. Both D. folliculorum and D. brevis can survive better at low temperatures than at high temperatures. The most suitable maintenance temperature is 5°C, and the optimal temperature for D. folliculorum and D. brevis to develop in vitro is 16–20°C. Temperatures below 0°C and above 37°C are harmful to the mites. The lethal temperature is 54°C, and the effective temperature that kills Demodex mites is 58°C.     

Prevalence of Demodex spp. in eyelash follicles in different populations

Introduction

The pathologic relevance of Demodex infestation in blepharitis is still controversial. The aim of the study was to determine the prevalence of Demodex spp. in eyelash follicles and its relationship to eye symptoms.

Material and methods

A total of 290 individuals were studied for the presence of Demodex folliculorum and Demodex brevis within eyelash follicles. Participants belonged to one of four groups: inpatients, drug abusers, health professionals, and medical students. Ten eyelashes were epilated from each subject, placed on microscope slides and examined for parasites. The sample was defined as positive if at least one parasite or parasite''s ova were present. The presence of parasites was analyzed according to age, gender, place of living, reported eye problems, and use of contact lenses or glasses.

Results

The prevalence of Demodex spp. infestation among all studied subjects was 41%, with the highest infestation rate among inpatients (p < 0.01) and elderly people (p < 0.001). No difference regarding the presence of Demodex was found between women and men (p = 0.76). Demodex folliculorum was about 2.4 times more frequent than D. brevis. The prevalence of Demodex spp. in subjects with and without eye complaints suggesting blepharitis was similar (41.6% vs. 40.2%, respectively, p = 0.9). On the other hand, wearing glasses was linked to Demodex infestation (48.4% vs. 32.3%, p < 0.01).

Conclusions

Demodex is a common saprophyte found in human eyelash follicles. Its presence might be related to some ocular discomfort; however, in the vast majority of cases the infestation seems to be asymptomatic.     

Morphobiometrical and molecular study of two populations of <Emphasis Type="Italic">Demodex folliculorum</Emphasis> from humans

A morphobiometrical and molecular study of two populations of Demodex folliculorum from humans isolated from different habitats, skin and eyelashes follicles, were carried out. Morphological and biometrical studies revealed two closely related populations with any distinctive characteristics. For molecular study, a 436-bp region of the 16S rDNA gene and a 453-bp region of the cytochrome oxidase I (COI) gene from individual mites of each population considered were sequenced. Intraindividual and interindividual sequence variation was studied in both populations. Our data show that 16S rDNA is not a useful marker to discriminate between populations; however, COI gene sequences can help to identify the two populations considered, which are morphologically very close and difficult to separate by classic methods. These results are in agreement with the morphological and biometrical differences detected between D. folliculorum from eyelashes and human skin. This study appeals for the revision of the taxonomic status of the D. folliculorum populations, as well as for the species included within genus Demodex.     

Associations between Demodex species infestation and various types of cancer

Tumor-associated immune system cells secrete protease and cytokines that can inhibit the immune response. In particular, T-cell effector functions could be inhibited, potentially causing an increase in parasitic infestations. Demodex species are common inhabitants of normal hair follicles. Humans are the specific host for two species Demodex folliculorum and D. brevis. The aim of this study was to investigate the incidence and infestation of D. folliculorum and D. brevis in patients with cancer. In the present study, 101 patients with cancer were selected from among patients who were diagnosed and treated for cancer. The cancer patients were divided into four groups according to cancer type. Slides were examined for parasites using light microscopy at magnifications of ×40 and ×100. Infestation was defined as having at least five living parasites/cm² of skin. The ages of the patients with cancer ranged between 38 and 82 years, with a mean of 65.5±10.1 years. It was determined that 77 of the 101 (76.2%) cancer patients were positive for Demodex species. Infestation was positive in 18 (47.4%) of the 38 cases in the breast cancer group, 7 (29.2%) of the 24 cases in the lung cancer group, 5 (18.5%) of the 27 cases in the gastrointestinal system cancer group, and 2 (16.7%) of the 12 cases in the urogenital system cancer group. Results showed that the rate of Demodex species infestation was higher in patients with breast cancer. Thus, cancer — and particularly breast cancer — is a risk factor for Demodex species infestation.     

Sequencing for complete rDNA sequences (18S, ITS1, 5.8S, ITS2, and 28S rDNA) of Demodex and phylogenetic analysis of Acari based on 18S and 28S rDNA

Due to the difficulty of DNA extraction for Demodex, few studies dealt with the identification and the phyletic evolution of Demodex at molecular level. In this study, we amplified, sequenced, and analyzed a complete (Demodex folliculorum) and an almost complete (D12 missing) (Demodex brevis) ribosomal DNA (rDNA) sequence and also analyzed the primary sequences of divergent domains in small-subunit ribosomal RNA (rRNA) of 51 species and in large-subunit rRNA of 43 species from four superfamilies in Acari (Cheyletoidea, Tetranychoidea, Analgoidea, and Ixodoidea). The results revealed that 18S rDNA sequence was relatively conserved in rDNA-coding regions and was not evolving as rapidly as 28S rDNA sequence. The evolutionary rates of transcribed spacer regions were much higher than those of the coding regions. The maximum parsimony trees of 18S and 28S rDNA appeared to be almost identical, consistent with their morphological classification. Based on the fact that the resolution capability of sequence length and the divergence of the 13 segments (D1–D6, D7a, D7b, and D8–D12) of 28S rDNA were stronger than that of the nine variable regions (V1–V9) of 18S rDNA, we were able to identify Demodex (Cheyletoidea) by the indels occurring in D2, D6, and D8.     

Association study of <Emphasis Type="Italic">Demodex</Emphasis> bacteria and facial dermatoses based on DGGE technique

The role of bacteria is unclear in the facial skin lesions caused by Demodex. To shed some light on this issue, we conducted a case-control study comparing cases with facial dermatoses with controls with healthy skin using denaturing gradient gel electrophoresis (DGGE) technique. The bacterial diversity, composition, and principal component were analyzed for Demodex bacteria and the matched facial skin bacteria. The result of mite examination showed that all 33 cases were infected with Demodex folliculorum (D. f), whereas 16 out of the 30 controls were infected with D. f, and the remaining 14 controls were infected with Demodex brevis (D. b). The diversity analysis showed that only evenness index presented statistical difference between mite bacteria and matched skin bacteria in the cases. The composition analysis showed that the DGGE bands of cases and controls were assigned to 12 taxa of 4 phyla, including Proteobacteria (39.37–52.78%), Firmicutes (2.7–26.77%), Actinobacteria (0–5.71%), and Bacteroidetes (0–2.08%). In cases, the proportion of Staphylococcus in Firmicutes was significantly higher than that in D. f controls and D. b controls, while the proportion of Sphingomonas in Proteobacteria was significantly lower than that in D. f controls. The between-group analysis (BGA) showed that all the banding patterns clustered into three groups, namely, D. f cases, D. f controls, and D. b controls. Our study suggests that the bacteria in Demodex should come from the matched facial skin bacteria. Proteobacteria and Firmicutes are the two main taxa. The increase of Staphylococcus and decrease of Sphingomonas might be associated with the development of facial dermatoses.     

The first case of Demodex gatoi in Austria, detected with fecal flotation

Feline demodicosis is a rare parasitic condition caused by three different species of mites (Demodex cati, Demodex gatoi, and an unnamed species). D. gatoi inhabits the superficial skin layer (stratum corneum) and is easily transmitted between individual cats. A 2-year-old female spayed Cornish Rex was presented with alopecia and pruritus. The dermatological examination revealed bilateral alopecia and excoriations on trunk, limbs, and belly. The second cat in the household, a 3-year-old female spayed Thai, showed no clinical signs. Superficial and deep skin scrapings were performed and cellophane tapes applied, and living D. gatoi mites could be detected in both cats. Oral ivermectin (0.25 mg/kg every other day) was subscribed. Feces were collected from both cats and fecal flotation with sugar and zinc solutions performed. When compared to skin scrapings and cellophane tapes, D. gatoi was detected more frequently and in higher numbers in fecal samples. Our findings suggest that D. gatoi can be efficiently diagnosed with coproscopy, particularly in asymptomatic carrier animals. DNA was extracted from the flotation liquid, and a PCR protocol for the species verification was designed. A fragment targeting a 325-bp DNA fragment of the D. gatoi mitochondrial 16S rDNA gene was amplified with a 100 % similarity to the D. gatoi entry in GenBank® (GI 421920216). We report the first finding of D. gatoi in Austria and propose fecal flotation as a valuable tool for mite detection. Fecal flotation liquid is suitable for DNA extraction and PCR-based species verification of D. gatoi.     

Morphological, biometrical, and molecular characterization of Ctenocephalides felis and Ctenocephalides canis isolated from dogs from different geographical regions

In the present work, a comparative morphological, biometrical and molecular study of Ctenocephalides spp. isolated from dogs (Canis lupus familiaris) from different geographical regions (Spain, Iran, and South Africa) has been carried out. The internal transcribed spacer 1 (ITS1) sequences of Ctenocephalides felis and Ctenocephalides canis collected from dogs from different geographical regions have been determined to clarify the taxonomic status of these species and to assess intraspecific variation and interspecific sequence differences. In addition, a phylogenetic analysis based on ITS1 sequences has been performed. Four different morphological populations were observed in the individuals of C. felis collected from dogs from different geographical locations. Nevertheless, the comparative study of the ITS1 sequences of the different morphological populations observed in C. felis did not show molecular differences. The results showed clear molecular differences between C. felis and C. canis and some specific recognition sites for endonucleases were detected between both species. Thus, BfrBI and DraI sites have diagnostic value for specific determination in C. felis. The phylogenetic tree based on the ITS1 sequences of C. felis and C. canis revealed that all the populations of C. felis from different geographical regions clustered together and separated, with high bootstrap values, from C. canis. We conclude that ITS1 region is a useful tool to approach different taxonomic and phylogenetic questions in Ctenocephalides species.     

Ectoparasites of dogs and cats in Albania

One hundred eighty-one dogs and 26 short-hair cats from suburban areas around Tirana, Albania were examined for ectoparasite infestation. The dogs were examined on several occasions from 2005 through 2009 representing three seasons: winter (December–February), spring (March–May), and summer (June–August); the cats were examined in late autumn (November). In addition, deep ear swab specimens of 30 dogs were examined for ear mites. The arthropod ectoparasite fauna of the dogs included two tick species (Rhipicephalus sanguineus and Ixodes ricinus), three mite species (Sarcoptes scabiei var. canis, Otodectes cynotis, and Demodex canis), three flea species (Ctenocephalides canis, Ctenocephalides felis, and Pulex irritans), and one louse species (Trichodectes canis). In the dogs, rates of infestation were 23.8% for R. sanguineus, 0.6% for I. ricinus, 4.4% for S. scabiei var. canis, 6.7% for O. cynotis, 0.6% for D. canis, 75.7% for C. canis, 5.0% for C. felis, 8.3% for P. irritans, and 6.6% for T. canis. Mixed infestation with two or three species of ectoparasites was recorded on 38.1% of the dogs. Fleas infested 75.7% dogs (geometric mean, 3.96; range, 1–80) and were observed in winter, spring, and summer with increasing prevalences of 64.3%, 75.9%, and 100%. Ticks parasitized 24.3% of the dogs (geometric mean, 0.41; range, 1–331). R. sanguineus ticks were recorded on 34.2% and 50% of the dogs examined in spring and summer, respectively, but were absent on the dogs during winter except for a single I. ricinus specimen observed. Prevalence of infestation with R. sanguineus, S. scabiei var. canis, C. felis, P. irritans, and T. canis did not differ between dogs ≤6 months and dogs >6 months of age; however, prevalence of infestation with C. canis was significantly (p?<?0.01) higher in dogs >6 months old. There was no difference between the sexes for the prevalences of infestation with those parasites. The examination of the cats revealed infestation with only one species of ectoparasite, C. felis (prevalence, 100%; geometric mean, 2.5; range, 1–9).     

<Emphasis Type="Italic">Demodex folliculorum</Emphasis> in patients with rheumatoid arthritis

The objective of this study was to investigate the incidence and density of Demodex folliculorum in the patients with rheumatoid arthritis (RA). Forty-one patients with RA and twenty-seven age and sex matched healthy controls were enrolled in this study. Disease Activity Score (DAS 28) was used for the assessment of disease activity. Out of 41 patients, 33 were females and 8 males. The mean disease duration was 10.9 ± 8.2 years. The mean DAS 28 was 3.8 ± 1.2. No statistically significant differences in the incidence and density of Demodex mites were found between patients with RA and controls. Although immunosuppression is thought to be a risk factor for the D. folliculorum infestation no such correlations could be found in the 41 immunosuppressed patients with RA, therefore, further studies with larger groups are needed.     

Sequential Evaluation of Dogs Naturally Infected with Ehrlichia canis, Ehrlichia chaffeensis, Ehrlichia equi, Ehrlichia ewingii, or Bartonella vinsonii

Historically, disease manifestations in dogs seroreactive to Ehrlichia canis antigens by indirect immunofluorescent antibody testing have been attributed to infection with either E. canis or Ehrlichia ewingii. A 1996 study by Dawson and colleagues provided PCR evidence that healthy dogs from southeastern Virginia could be naturally infected with Ehrlichia chaffeensis. This observation stimulated us to determine which Ehrlichia spp. infected sick dogs that were referred to our hospital from the same region. Based upon PCR amplification with species-specific primers, sick dogs seroreactive to E. canis antigens were determined to be infected with four Ehrlichia species: E. canis, E. chaffeensis, E. equi, and E. ewingii. Coinfection with three Ehrlichia species (E. canis, E. ewingii, and E. equi) was documented for one dog. An additional canine pathogen presumed to be tick transmitted, Bartonella vinsonii subsp. berkhoffii, was identified in 7 of 12 dogs. Importantly, our results indicate that in naturally infected dogs, E. chaffeensis can cause severe disease manifestations that are clinically and serologically indistinguishable from disease manifestations of E. canis or E. ewingii. In addition, our findings support the efficacy of doxycycline for treatment of E. canis, E. equi, and E. ewingii infections but indicate that, based upon the persistence of E. chaffeensis DNA for 1 year following treatment, E. chaffeensis infection in dogs may be more refractory to doxycycline treatment. Undetected coinfection with Bartonella may also complicate the evaluation of treatment efficacy while resulting in disease manifestations that mimic ehrlichiosis.     

Demodex-associated dermatologic conditions – A coincidence or an etiological correlate. Review with a report of a rare case of sebaceous adenoma

Demodex folliculorum is a saprophytic mite of the human pilosebaceous unit with a prelidiction for facial skin and eyelashes. Infestation occurs frequently without symptoms; however, suppurative or granulomatous inflammation may be seen with high mite density. Skin lesions, such as rosacea, pityriasis, and blepharitis, have been attributed to Demodex; however, its role in sebaceous adenoma (SA) has not been reported in extensively searched medical literature. We report this rare case and review the skin lesions associated with Demodex folliculorum.     

Phylogenetic relationships in Demodex mites (Acari: Demodicidae) based on mitochondrial 16S rDNA partial sequences

To confirm phylogenetic relationships in Demodex mites based on mitochondrial 16S rDNA partial sequences, mtDNA 16S partial sequences of ten isolates of three Demodex species from China were amplified, recombined, and sequenced and then analyzed with two Demodex folliculorum isolates from Spain. Lastly, genetic distance was computed, and phylogenetic tree was reconstructed. MEGA 4.0 analysis showed high sequence identity among 16S rDNA partial sequences of three Demodex species, which were 95.85?% in D. folliculorum, 98.53?% in Demodex canis, and 99.71?% in Demodex brevis. The divergence, genetic distance, and transition/transversions of the three Demodex species reached interspecies level, whereas there was no significant difference of the divergence (1.1?%), genetic distance (0.011), and transition/transversions (3/1) of the two geographic D. folliculorum isolates (Spain and China). Phylogenetic trees reveal that the three Demodex species formed three separate branches of one clade, where D. folliculorum and D. canis gathered first, and then gathered with D. brevis. The two Spain and five China D. folliculorum isolates did not form sister clades. In conclusion, 16S mtDNA are suitable for phylogenetic relationship analysis in low taxa (genus or species), but not for intraspecies determination of Demodex. The differentiation among the three Demodex species has reached interspecies level.     

Molecular survey and genetic characterization of tick-borne pathogens in dogs in metropolitan Recife (north-eastern Brazil)

To identify DNA of the main tick-borne pathogens in dogs from Recife (Brazil), polymerase chain reactions were carried out on blood samples of dogs treated at the Veterinary Hospital of the Universidade Federal Rural de Pernambuco from March 2007 to June 2008. The detection of DNA was performed using specific primers. Amplicons were analyzed through electrophoresis and sequencing. A phylogenetic tree was constructed using the UPGMA method, revealing that the sequences were closely related to those of strains from other geographic regions. Among the 205 blood samples analyzed, 48.78% was positive for Anaplasma platys; 38.04% was positive for Ehrlichia canis; 7.31% was positive for Babesia canis vogeli; and 0.49% was positive for Hepatozoon canis and Mycoplasma haemocanis. Coinfection of two or three pathogens was found in 23.9% (49/205) of the dogs. The subspecies B. canis vogeli was identified. Infection by H. canis and M. haemocanis is reported for the first time in dogs in the state of Pernambuco (Brazil). The data indicate that the main tick-borne pathogens in dogs in this region are E. canis and/or A. platys, followed by B. canis vogeli.     

Nodular dermatitis as an atypical form of canine demodicosis in an English bulldog

This case report describes the unusual clinical findings in a 2-year-old English bulldog with generalized demodicosis. The dog was referred with a 2-month history of generalized pruritus, alopecia, lichenification, and nodular lesions. A complete series of dermatologic tests such as Wood's light examination, direct microscopic examination, and fungal culture were performed. In the deep skin scrapings Demodex canis was identified by microscopic examination. A punch biopsy was taken from nodules and histological examination revealed that the large numbers of mites were located both in the lumen of hair follicles and sebaceous glands which provoked granulomatous responses in the dermis. The dog was treated topically every 7 days for a total of eight treatments with an amitraz solution. The treatment resulted in a marked decrease in the number of skin nodules. Complete clinical cure was achieved following 2 months of treatment. Although generalized demodicosis is a well-known parasitic skin disease in dogs, the present clinical case represents an alert to practitioners about the atypical clinical form of demodicosis in dogs.     

Molecular identification and characterization of canine Hepatozoon species from Brazil

Canine Hepatozoon species from Brazil was molecular identified and characterized for the first time. From 31 dogs, 7 were positive for blood smear examination and 21 positive for PCR. Partial sequences of the 18S rRNA gene from eight naturally infected dogs were analyzed. Sequences revealed that Brazilian Hepatozoon is closely related with the Japanese Hepatozoon, that has 99% nucleotide identity with Hepatozoon canis from Israel, and different from Hepatozoon americanum. These results indicate that the canine Hepatozoon species from Brazil is H. canis.