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1.
Abstract Macroscopic and cytological aspects of anal sac content were evaluated in 40 normal dogs and 10 dogs each with pyoderma, Malassezia dermatitis associated with atopic dermatitis and uncomplicated atopic dermatitis. Bacteria isolated from anal sacs were compared with those from abdominal skin and hair in 20 normal dogs and 10 dogs with pyoderma. There was no difference between the groups in anal sac dimension, or in the colour, consistency or presence of granules in their content. Extracellular bacteria were found in higher numbers in diseased animals, whereas intracellular bacteria were observed in 40% of dogs with pyoderma and in only 2.5% of normal dogs. Malassezia spp. were present in 15.7% of dogs, with no difference between groups. Neutrophils were observed in 12.5% of normal dogs, 30% of dogs with Malassezia dermatitis with underlying atopic dermatitis and in 70 and 80% of dogs with pyoderma and uncomplicated atopic dermatitis, respectively. Seven bacterial species were isolated from anal sacs, with no difference between normal dogs and dogs with pyoderma. In five normal animals and in four dogs with pyoderma the same bacterial strains were isolated from anal sacs and from abdominal skin and hair.  相似文献   

2.
The bacterial and fungal flora of the external ear canal of dogs with otitis externa and of healthy dogs were studied. The most frequently isolated microorganism from otitic ears was Staphylococcus intermedius (58.8%), followed by Malassezia pachydermatis (30.9%), Streptococcus canis (29.9%), Proteus spp. (14.4%) and Escherichia coli (10.3%). A statistical analysis of our results showed that the prevalence of these microorganisms is significant in dogs with otitis externa. Furthermore, the antimicrobial susceptibility patterns of isolated strains were determined. Majority of all bacterial isolates were most susceptible to gentamicin. Malassezia pachydermatis, the most prevalent yeast in this study, showed an excellent level of susceptibility to all antifungal agents tested.  相似文献   

3.
Malassezia species are commensal organisms of human and animal skin that occasionally act as opportunistic pathogens. The lipid-dependent species are associated with human skin disorders, whereas the non-lipid-dependent species (Malassezia pachydermatis) is considered as an opportunistic secondary pathogen affecting the canine skin surface and ear canal. This study evaluated the relationship between Malassezia yeasts, their population size, and the occurrence of skin lesions from healthy and skin-diseased dogs. The efficiency of cytological examination and fungal culture for Malassezia detection was also evaluated. From March 2002 to July 2003, 33 healthy dogs and 54 dogs with pruritic localized skin diseases were examined; skin swabs (1218) were collected from 7 anatomical sites for culture and cytological examination. Malassezia prevalence according to anatomical site and the agreement between cytological results and fungal cultures were statistically analyzed. Differences in mean colony forming unit counts between positive healthy and diseased dogs were evaluated using the Bonferroni test for post hoc pair-wise comparisons. In healthy dogs, Malassezia yeasts were most frequently isolated in the perianal and perioral areas. The frequency of isolation and population size of Malassezia species were higher in dogs with localized dermatitis, especially in affected areas, indicating a role for Malassezia in the occurrence of skin lesions. Malassezia pachydermatis was the species most commonly cultured from the skin and external ear canal of healthy and diseased dogs; isolation of lipid-dependent yeasts from healthy dogs was less frequent. Using fungal culture as the gold standard, cytological examination showed good relative specificity (95%) but very low relative sensitivity (30%).  相似文献   

4.
The prevalence of gastrointestinal parasites in stray dogs, and dogs with owners was investigated by fecal examinations from 271 dogs employing sedimentation, simple flotation and centrifugation-flotation methods. The centrifugation-flotation method, when compared to simple flotation or sedimentation methods was generally more accurate in the diagnosis of all intestinal parasites, but statistical differences were detected only in relation to Giardia spp. and Cystoisospora spp. (synonym Isospora spp.). The following parasites, with their respective prevalence, were diagnosed in the fecal samples: Ancylostoma spp. (23.6%); Toxocara canis (5.5%); Trichuris vulpis (4.8%); Spirocerca lupi (1.9%); Dipylidium caninum (0.7%); Giardia spp. (12.2%); Hammondia heydorni (2.6%); Cystoisospora spp. (8.5%); and Sarcocystis spp. (2.2%). The prevalence of most parasites was similar for dogs of mixed-breed and for dogs of a defined-breed, except for Cystoisospora spp. and T. canis which showed a significantly higher prevalence in mixed-breed dogs. The prevalence of Ancylostoma spp. (17.1%) was significantly lower in stray dogs than in those with an owner (31.9%) and the prevalence of Giardia spp. and Cystoisospora spp. was higher in stray dogs (P < 0.05). No effect of season on the occurrence of the different parasite genera could be observed, except for Ancylostoma spp., for which an increase in the percentage of dogs shedding eggs was observed at the beginning of Summer with a peak occurrence during April and May (Autumn). The prevalence of Ancylostoma spp., T. canis, T. vulpis, Giardia spp. and Cystoisospora spp. was higher in adult males than in adult females, but significant differences between the two groups occurred only with Giardia spp. Young animals were found to more frequently shed Nematode eggs in feces than adult animals.  相似文献   

5.
IgG immunoreactivity to Malassezia pachydermatis was compared in atopic and non-atopic dogs. Malassezia pachydermatis proteins with a molecular weight of 98 kDa were recognized at a significantly higher frequency in the sera of atopic dogs. Most of the atopic dogs with Malassezia dermatitis had a greater IgG response than did normal dogs.  相似文献   

6.
Malassezia spp. yeasts are commensal organisms of mammal and avian skin, but little is known about their presence on the skin of healthy cats. The purposes of this study were to evaluate the prevalence of Malassezia spp. yeasts in feline nail folds and to identify the different species. Forty-six cats of different breeds were evaluated by cytological examination, and Malassezia spp. yeasts were seen in 61% of them. Yeasts were found in 100% of Devon Rex cats [mean 8.63/oil immersion field (high-power field - HPF)]. Conversely, only 42% of cats of other breeds (domestic short-haired and Persian) were positive (mean 0.59/HPF). Twenty-one cats of different breeds were subsequently evaluated by fungal culture. Malassezia pachydermatis was isolated from 52%, M. furfur from 38%, and M. sympodialis from 9.5% of the cats. More than one species was observed in eight of 21 cats, six of which were Devon Rex. Malassezia spp. yeasts are common inhabitants of feline nail folds, especially in Devon Rex cats, and the presence of a high number of yeasts on cytology correlates with the clinical observation of brown, greasy material in the nail folds. M. pachydermatis and two lipid-dependent species were isolated from both Devon Rex cats and cats of other breeds.  相似文献   

7.
OBJECTIVE: To investigate the potential cell-mediated immune response of atopic dogs to the yeast Malassezia pachydermatis and to correlate it with the type-1 hypersensitivity (humoral) response of the same population of dogs. ANIMALS: 16 clinically normal dogs, 15 atopic dogs with Malassezia dermatitis, 5 atopic dogs with Malassezia otitis, and 7 atopic control (ie, without Malassezia dermatitis or otitis) dogs. PROCEDURE: A crude extract of M pachydermatis was extracted for use as an intradermal allergy testing reagent and for stimulation of isolated peripheral blood mononuclear cells in vitro. Flow cytometry was also used to assess cell surface antigenic determinants (CD3, CD4, CD8, CD14, CD21, CD45RA, surface immunoglobulin) on peripheral blood mononuclear cells. RESULTS: Atopic dogs with cytologic evidence of Malassezia dermatitis had an increased lymphocyte blastogenic response to crude M pachydermatis extract, compared with clinically normal dogs and dogs with Malassezia otitis. Atopic control dogs did not differ significantly in their responses from atopic dogs with Malassezia dermatitis or otitis. A significant correlation was not found between the lymphocyte blastogenic response and the type-1 hypersensitivity response to M pachydermatis within any of the groups. CONCLUSIONS AND CLINICAL RELEVANCE: Cell-mediated and humoral reactivities to M pachydermatis contribute to the pathogenesis of atopic dermatitis in dogs but are not directly correlated. Modification of the dysregulated immune response toward M pachydermatis may assist in the reduction of pathologic changes associated with an atopic dermatitis phenotype in dogs.  相似文献   

8.
The prevalence of intestinal parasites in dogs presented to the Veterinary Policlinic of the University of Zulia (PVU) was measured between January and December 2001. A total of 614 fecal samples were evaluated by the fecal flotation method. One or more species of parasites was identified in 218 (35.5%) dogs. The parasites most frequently detected were: Ancylostoma spp. (24.5%), Toxocara canis (11.4%) and Isospora spp. (8.1%). Single parasitic infections were present in 149 (24.3%) dogs. The age distribution of intestinal parasites in dogs less than 1 year old had a higher overall prevalence than those dogs over 12 months of age. There was no significant difference in the prevalence between male (38.9%) and female (31.7%) dogs. There was a significantly (P < 0.05) greater prevalence of parasites in mixed-breed dogs (40.3%) as compared with pure-breed dogs (30.8%). A significant difference (P < 0.05) was detected between the general prevalence of January and December compared to August.  相似文献   

9.
Malassezia pachydermatis is considered to be a contributing factor to canine atopic dermatitis (AD). The purpose of this study was to investigate the humoral response to a commercially produced M. pachydermatis extract. Fifteen atopic dogs with Malassezia overgrowth on the skin (MD), 16 atopic dogs without MD, three atopic dogs with overgrowth of Malassezia in the ears only (MO), and 12 normal dogs were intradermally tested with M. pachydermatis extract at 50, 100, 250, 500, 1000, 2000 and 4000 PNU mL(-1). All dogs were evaluated cytologically by cutaneous tape strip and bilateral ear exudate sampling to determine presence of MD or MO. Each had serum evaluated for anti-Malassezia IgE using three Malassezia extracts with an ELISA assay. The irritant threshold concentration at which healthy nonatopic dogs ceased to react was 1000 PNU mL(-1). There was a significant difference in intradermal test reactivity between the atopic groups. At this dilution, 93% (14/15) of the atopic MD group, 31% (5/16) of the atopic group without MD or MO, and 100% (3/3) of the atopic MO only group reacted. There were no significant differences in the serum IgE levels as measured by the Greer ELISA assay, between any groups using any of the three extracts. These results support that Greer's M. pachydermatis extract is useful for intradermal testing of dogs with an allergic phenotype, and that atopics with MD are more likely to have a type-1 Malassezia hypersensitivity than those without. The ELISA assay may require further development in order to be useful for the diagnosis of Malassezia hypersensitivity.  相似文献   

10.
Aim of the present study was to determine the distribution and quantification of Malassezia yeasts on a wide number of cutaneous sites in atopic dogs by means of a semiquantitative swab technique. A possible relationship between the presence of clinical signs and the occurrence and population size of yeasts was attempted. Forty-one privately owned atopic dogs of different age and breed were sampled. Results were expressed as colony forming units per swab. Malassezia colonies obtained from each plate were counted, scored and typed. All dogs yielded Malassezia pachydermatis from at least one skin area. Yeast population mean size by site was 6.98 (S.D.=3.47) as compared to other body areas. The frequence of isolation was higher from interdigital areas (70.7%), ears (63.4%), nail folds (35.7%), mouth (33.3%), groin (30.9%), conjunctiva and axillae (23.8%), perineum and anus (19%), perianal glands (9.5%). Ears, anus, interdigital areas, perianal glands and groin yielded the largest mycotic amount. M. pachydermatis was the sole species of yeast to colonize canine skin in examined animals. No statistical correlation between the presence of cutaneous alterations and Malassezia isolation was detected. Highest scores were not exclusively found on affected areas, but also on lesion-free sites, demonstrating that atopic animals can be heavily colonized also in apparently healthy areas.  相似文献   

11.
In 12 cases of lethal acrodermatitis (LAD), four sampling techniques (brush, swab, scrape and adhesive tape strip) were used to study the distribution of yeasts in various body sites and these results were compared with those from five cases of atopic dermatitis and those of 10 normal dogs. Malassezia was frequently isolated from lesional and non-lesional skin and haircoat, footpads, nails and mucous membranes from dogs with either LAD or atopic dermatitis, although, generally, more Malassezia organisms were isolated from LAD cases. In normal dogs, Malassezia was most frequently recovered from the ear canal and the perianal skin. Candida was isolated frequently from dogs with LAD, but only a single isolate of this yeast was found in the other two groups. Fungal hyphae and pseudohyphae, probably Candida albicans, could be detected in samples collected from the nails and footpads of dogs with LAD. Both Malassezia and Candida could be isolated using all four sampling techniques. The MacKenzie (toothbrush) technique and adhesive tape strip cultures proved simple methods for the semiquantitative evaluation of yeasts. The high recovery rate of Malassezia and Candida from dogs with LAD is probably related to immune dysfunction, particularly T-cell dysfunction, known to be present in these dogs. C albicans infection may in part be responsible for the pathogenic changes of the nails and footpads commonly seen in cases of LAD.  相似文献   

12.
A total of 281 faecal samples from owned shepherd and hunting dogs were collected in the Serres Prefecture, Northern Greece and were examined for the presence of intestinal parasites. The overall prevalence of parasitism was 26% and the 11 species found were: Toxocara canis (12.8%), Trichuris vulpis (9.6%), Giardia spp. (4.3%), Isospora (Cystoisospora) spp. (3.9%), Ancylostoma/Uncinaria spp. (2.8%), Cryptosporidium spp. (2.8%), Alaria alata (2.5%), Strongyloides stercoralis (1.8%), Angiostrongylus vasorum (1.1%), Toxascaris leonina (0.7%) and Dipylidium caninum (0.3%). The prevalence of T. canis and Isospora (Cystoisospora) spp. was significantly higher in young than in adult dogs (p < 0.05). There was no significant difference in prevalence between genders, except for T. canis, which was more common in male dogs (p < 0.05).  相似文献   

13.
The purpose of this study was to investigate the diversity of yeast associated with the degree of canine seborrheic dermatitis (SD) by anatomical sites. Fifty-seven samples were divided as 17 healthy skin, 20 with primary seborrheic dermatitis (PSD), and 20 with secondary seborrheic dermatitis (SSD). Yeast isolation and characterization were carried out based on microscopical features and biochemical properties. DNA analysis at the internal transcribed spacer I of 26S rDNA region was utilized for species confirmation. Four species of yeast consisting Malassezia pachydermatis, Malassezia furfur, Candida parapsilosis and Candida tropicalis recovered from examined dogs. M. pachydermatis and C. parapsilosis were isolated from all dogs, but C. tropicalis and M. furfur were recovered from 3 healthy dogs and one diseased dog, respectively. The number of M. pachydermatis and C. parapsilosis in diseased dogs was higher than that of healthy specimens (P<0.01). High frequency and population size of C. parapsilosis were closely associated to PSD, while those of M. pachydermatis were associated with both PSD and SSD (P<0.01). C. parapsilosis were predominant at the perianal area. This study demonstrated the co-colonization of M. pachydermatis and C. parapsilosis in large amounts and frequency associated with stage of disease and anatomical site.  相似文献   

14.
To investigate the role of Malassezia pachydermatis as a pathogenic agent in canine otitis, a comparative analysis of isolates from normal and diseased external ear canals in dogs was undertaken. Specimens were collected from the ears of dogs with unilateral or bilateral otitis and from healthy dogs. Mycological analysis was by direct microscopy and fungal culture on Sabouraud's dextrose agar and Dixon's agar. Of the otitis specimens, 63.7% showed typical Malassezia cells on cytological examination. In samples taken from the healthy ears of dogs with unilateral otitis, only 21.43% (P<0.05) showed evidence of Malassezia. M. pachydermatis was identified cytologically and culturally in 57.53% (P<0.05), 14.29% and 30.0% of samples from the ears of dogs with otitis, from the healthy ears of dogs with unilateral otitis and from the ears of healthy dogs with no otitis. In the group with otitis associated with M. pachydermatis, the poodle was the most common breed (39.29%; P<0.05), whereas in the group without otitis, the German Shepherd breed was prominent (although this observation was not statistically significant). In both groups, the majority of dogs with M. pachydermatis were aged between 1 and 3 years (P<0.05). The higher incidence of M. pachydermatis isolated from the ears of dogs with otitis externa suggests a putative pathogenic role of this yeast in this condition.  相似文献   

15.
Abstract We have previously shown that both atopic and normal dogs generate an IgG response to antigens of Malassezia pachydermatis . The aim of this study was to compare IgE responses to separated proteins of M. pachydermatis in 28 atopic dogs with Malassezia dermatitis and 22 clinically normal dogs using Western immunoblotting. Six different detection systems were evaluated in order to assess sensitivity and eliminate nonspecific binding and cross-reactivity. The protocol yielding the best results utilized a monoclonal mouse antidog IgE, an alkaline phosphatase conjugated goat antimouse IgG which had been passed through a canine IgG column 3 times, a chemiluminescent substrate and a digital imaging system. Proteins of 45, 52, 56 and 63 kDa were recognized by more than 50% of the atopic dog sera and thus represented major allergens. Only a minority of normal dogs showed faint IgE binding to these proteins. The results indicate that the majority of atopic dogs with Malassezia dermatitis have a greater IgE response than normal dogs, suggesting an IgE-mediated immune response may be clinically important in the pathogenesis of the disease.  相似文献   

16.
OBJECTIVE: To investigate the direct interaction between canine keratinocytes and live Malassezia pachydermatis and thereby determine the role of these organisms in the pathogenesis of epidermal hyperplasia associated with Malassezia dermatitis in dogs. SAMPLE POPULATION: Primary canine keratinocyte cultures established from skin samples obtained from clinically normal dogs. PROCEDURE: The proliferative response of keratinocytes co-cultured with Malassezia organisms for 1, 2, or 3 days was assessed by use of direct manual counting (to determine the number of keratinocytes in both the monolayer and the medium) and immunohistochemical staining techniques involving antibodies against proliferating cell nuclear antigen (PCNA) and another cellular proliferation marker, Ki-67. The potential cytotoxic effect of Malassezia organisms was investigated by use of an apoptosis detection kit to label keratinocytes co-cultured with M. pachydermatis that underwent apoptosis. RESULTS: No stimulatory effect of Malassezia organisms on canine keratinocyte proliferation was detected via cell counting and immunohistochemical techniques. However, there was a significant increase in dead keratinocytes in the medium with increasing numbers of Malassezia organisms in the co-culture. More apoptotic cells were observed in keratinocyte monolayers co-cultured with high numbers of M. pachydermatis than there were in monolayers cultured without Malassezia organisms, and the number increased after prolonged incubation. CONCLUSIONS AND CLINICAL RELEVANCE: M. pachydermatis did not stimulate canine keratinocyte proliferation in vitro. The results suggested that the epidermal hyperplasia observed in dogs with Malassezia dermatitis is unlikely to be caused by a direct effect of the organism on the keratinocyte cell cycle, but is likely to involve other mechanisms.  相似文献   

17.
Malassezia spp. dermatitis, a rare disorder in cats, has previously been associated with immune suppression and internal malignancies. This study evaluates the presence and importance of Malassezia spp. in feline biopsy specimens submitted for histopathological examination. Five hundred and fifty haematoxylin and eosin-stained skin biopsy specimens received for histopathological examination between January 1999 and November 2000 were reviewed. Fifteen (2.7%) submissions contained Malassezia organisms in the stratum corneum of the epidermis or follicular infundibulum. Eleven of 15 cats presented with an acute onset of multifocal to generalized skin lesions. All 11 cats were euthanized or died within 2 months of the onset of clinical signs. Seven cats had dermatopathological changes and clinical signs supportive of paraneoplastic alopecia, and three cats had an interface dermatitis suggestive of erythema multiforme or thymoma-associated dermatosis. Histopathological changes were nonspecific in one cat that was euthanized 2 weeks following onset of severe pruritus and alopecia. In three cats, Malassezia spp. were found in localized sites (two chin, one footpads) and appeared inconsequential to their overall health status. One cat had Malassezia spp. in association with cutaneous demodicosis. These findings suggest that Malassezia yeast in dermatopathological specimens from multifocal or generalized lesions should prompt a thorough clinical work-up for internal neoplasia.  相似文献   

18.
Significant numbers of humans with atopic dermatitis develop Malassezia-specific IgE. Immediate skin-test reactivity to Malassezia has been demonstrated in atopic dogs. The aim of this study was to compare the serum IgG and IgE response to Malassezia in atopic dogs with and without clinical evidence of Malassezia dermatitis and/or otitis, nonatopic dogs with clinical evidence of Malassezia dermatitis and/or otitis and healthy dogs. Cytology was used to diagnose clinically significant Malassezia dermatitis and otitis. Contact plate cultures confirmed the validity of this technique. Reproducible enzyme-linked immunosorbent assays for Malassezia-specific IgG and IgE in canine serum were established. Atopic dogs had significantly higher serum IgG and IgE levels than either healthy dogs or nonatopic dogs with clinical evidence of Malassezia dermatitis and/or otitis. There was no significant difference in IgG and IgE levels between atopic dogs with and without clinical evidence of Malassezia dermatitis and/or otitis. The implications of these findings in the pathogenesis and management of canine atopic dermatitis are discussed.  相似文献   

19.
Enterohepatic Helicobacter spp. have been described colonizing the large intestine and liver of healthy and symptomatic subjects and are thought to have a role in the development of inflammatory bowel disease (IBD). The prevalence of enterohepatic Helicobacter spp. infection in dogs is largely unknown and to our knowledge there are no data about their potential pathogenic role. In light of these considerations, the aims of this study were (i) to assess the prevalence of enterohepatic Helicobacter spp. in colonic biopsies of symptomatic pet dogs and (ii) to evaluate a possible association between Helicobacter spp. colonization status (heavily colonized, poorly colonized and uncolonized biopsies) and histological lesions. Colonic biopsies from 27 pet dogs of different ages were evaluated by family Helicobacteraceae and enterohepatic Helicobacter spp. PCR, histology, and immunohistochemistry for the in situ detection of Helicobacter spp. organisms. 85% and 52% of colonic biopsies were positive by Helicobacteraceae and enterohepatic Helicobacter spp. PCR, respectively. Immunohistochemistry revealed Helicobacter spp. were localized both in the superficial mucus (55%) and within intestinal crypts (33%). Dogs with heavy enterohepatic Helicobacter spp. colonization were significantly younger and had a higher level of mucosal fibrosis/atrophy than dogs with uncolonized or poorly colonized biopsies (p<0.05). These findings contribute to widen current knowledge regarding canine enterohepatic Helicobacter spp., suggesting the infection is rather common in dogs and acquired at an early age. Furthermore, heavy colonization of colonic crypts is associated with chronic inflammatory lesions (fibrosis/atrophy), supporting the role of enterohepatic Helicobacter spp. in the development of canine IBD.  相似文献   

20.
The bacterial and fungal flora of 1118 ears of dogs with otitis externa and 100 ears of healthy control dogs were studied in order to isolate the causative agents. The yeast Malassezia pachydermatis (56%) was by far the most common organism in otitic dogs followed by the bacteria Staphylococcus intermedius (23%), Pseudomonas aeruginosa (12%), Proteus spp. (6%) and Streptococcus canis (5%). A statistical analysis of observed results showed that the incidence of these organisms is significant in otitic dogs. Many strains of S.intermedius, P.aeruginosa and Proteus spp. are resistant to antimicrobial agents commonly used to treat otitis externa. Therefore an antimicrobial susceptibility testing was performed using "Cobas Bact" for these bacterias. Furthermore, 80 strains of M.pachydermatis were submitted to identification-kits (API 20 CAUX, API STAPH, Cobas Micro). The observed results showed that an identification with these tests was not possible.  相似文献   

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