Isolation of Malassezia species from healthy cats and cats with otitis

Lipid-dependent Malassezia species have recently been cultured from veterinary specimens. The identification of Malassezia species isolates from animals is important to clarify the epidemiology of these lipophilic yeasts. Malassezia species were cultured from the external ear canals of 63 out of 99 cats with otitis and 12 of 52 (23%) healthy control cats. The rate of isolation in affected animals versus controls was highly significant ( P<0.01). Malassezia pachydermatis was isolated as a pure culture in 33 (45.2%) cats, associated with Malassezia globosa and Malassezia furfur in 20 (50%) and 17 (42.5%) animals, respectively. Three different species were isolated simultaneously in three cats (two cats with M pachydermatis, M globosa and M furfur, one subject with M pachydermatis, M furfur and Malassezia sympodialis). M globosa was isolated as the sole species in two animals. The present work confirms the presence of some lipid-dependent species of Malassezia in both healthy and otitic cats.

Multilocus sequencing typing of Pseudomonas aeruginosa isolates and analysis of potential pathogenicity of typical genotype strains from occupational oxyhelium saturation divers

BACKGROUND

Pseudomonas aeruginosa (P. aeruginosa) is a common microbe isolated from divers with ear and skin infections. To obtain the epidemic characters of the occurrence of the P. aeruginosa infection, multilocus sequence typing (MLST) was used to assess the genetic background of different strains isolated from divers involved in saturation diving.

METHODS

A total of 64 P. aeruginosa strains from naval divers were sequenced by multilocus sequence typing using seven housekeeping genes (acsA, aroE, guaA, mutL, nuoD, ppsA and trpE). The results were analyzed based on the P. aeruginosa international MLST database to obtain the allelic profiles and sequence types (STs). MLST data were analyzed by Bionumerics 4.0 (http: // pubmlst.org/mlstanalyse) using LIAN and eBURST. Twenty-eight strains with the typical genotype were selected for further analysis of pathogenic characteristics by Caenorhabditis elegans (C. elegans) fast killing model.

RESULTS

Data from MLST revealed a high STs diversity among the strains. Of the 64 strains, 53 strains were assigned to 19 STs, and the remaining 11 clones could not be assigned. ST274 accounted for 18.5% (12/64), and ST260 accounted for 15.62% (10/64). C. elegans killing assay showed that all the test strains had distinct virulent properties as compared with the negative control group. Clone 503-1 had the highest virulence and clone 54 had the lowest virulence as compared with the positive clinical group.

CONCLUSION

The P. aeruginosa strains carried by the occupational diver groups in Chinese regions have characteristically dominant STs, and have a relatively strong virulence as compared with the standard strain and the clinically isolated positive control strain.

[The comparative characteristic of the microflora species composition in the tympanic cavity, nasal mucous membrane and external ear mucosa in the course of experimental suppurative staphylococcal otitis]

The objective of the present work was to study the species composition of microflora in the suppurative exudate from the tympanic cavity in the course of development of experimental suppurative staphylococcal otitis and to identify the initial sites of migration of secondary pathogens. The experiments were carried out on 20 adult rabbits showing no signs of "spontaneous" otitis. Experimental staphylococcal suppurative otitis was induced in 17 of these animals. The microbiological study included isolation and identification of pure bacterial cultures with the use of the classical method. The initial sites of migration of secondary pathogens were detected from the results of comparison of the species composition of microflora in tympanic exudate and the mucous membrane of the nearest anatomical regions, such as the nasal cavity an external auditory canal. The data obtained indicate that suppurative exudate from the tympanic cavity is populated by polyflora containing secondary pathogens, besides the principal ones (Staphylococci). The large amounts of secondary pathogens penetrate into the tympanic cavity from the mucous membranes of the nasal cavity and nasopharynx. It is concluded that the rhinotubal system is the major pathway through which pathogenic microflora migrates into the middle ear.

Lepromatous leprosy with an uncommon presentation: a case report

28 yr old male presented with asymptomatic nodules and few well to ill defined papules on ears, asymmetrical nerve enlargement and evanescent tender nodules on the extremities without any infiltration of the skin and madarosis. Slit skin smear done from normal skin was BI 6+. Skin biopsy showed features of lepromatous leprosy.

Possible mode of emergence for drug-resistant leprosy is revealed by an analysis of samples from Mexico

Mexico is a country with sporadic leprosy cases, and the reemergence of drug resistance is a concern. In this study, molecular analysis of Mycobacterium leprae was employed to clarify the spread of drug-resistant leprosy. Thus, drug resistance-determining regions in the folP1, rpoB, and gyrA genes, which are associated with resistance to dapsone, rifampicin, and ofloxacin, respectively, were analyzed by direct sequencing of the PCR product. No mutations in the folP1 gene were observed in any of the 72 slit skin samples obtained from 38 patients, although two samples carrying a mutation at codon 425 in the rpoB gene, which confers resistance to rifampicin, a key component of multidrug therapy, were identified. In addition, a mutation at codon 91 in the gyrA gene, which correlates with ofloxacin resistance, was found in one sample. These results demonstrate the existence of rifampicin- and ofloxacin-resistant leprosy. Interestingly, wild-type and mutant sequences in the gyrA gene were found to coexist in one clinical sample. In addition, all three drug resistance-related mutations were found in only one of the two earlobes of the patients concerned, suggesting a possible pathway for the spread of drug-resistant M. leprae.

Necrotizing otitis externa: a new trend? Report of 6 atypical cases

Necrotizing otitis externa (OE) is traditionally seen in elderly diabetics and immunocompromised patients. During a 7-year period at our institution, we treated 6 patients with necrotizing OE who were not diabetic, who were not immunocompromised, and who were relatively young (age range: 27 to 65 yr; mean: 42.8). The necrotizing OE in these patients was less aggressive but just as severe as its usual presentation in older diabetic or immunocompromised patients. All 6 patients had evidence of bony erosion on computed tomography of the temporal bones, although 4 had negative findings on technetium-99m scintigraphy. Four of the 6 patients required mastoid exploration and fascia lata grafting, and the other 2 chose to undergo extensive daily microdebridements and intravenous antibiotics followed by 6 weeks of oral antibiotics. We recommend that a diagnosis of necrotizing OE be kept in mind when evaluating any patient who presents with severe otalgia, particularly in the presence of Pseudomonas aeruginosa infection of the external auditory canal, edema, granulation tissue, and bony erosion.

[Pigs as an infection source for methicillin resistant Staphylococcus aureus infections in humans]

Recent Dutch studies indicate that methicillin-resistant Staphylococcus aureus (MRSA) sequence type 398 is widely distributed in pigs and may give rise to infection in humans. In this study we present the first two Danish cases of MRSA infection, which in all probability were acquired from occupational contact with pigs. One infection presented as a severe surgical wound infection, following knee surgery, the other as a superficial ear lobe infection. Both MRSA strains were multiresistant, sequence type 398, Spa-type t034, and Panton-Valentine leukocidin-encoding gene negative.

Methicillin-resistant Staphylococcus aureus colonization and its association with infection among infants hospitalized in neonatal intensive care units

OBJECTIVES

We conducted this study to assess the rate of methicillin-resistant Staphylococcus aureus colonization and its association with infection among infants hospitalized in methicillin-resistant S aureus-endemic NICUs.

METHODS

Between March 2003 and February 2004, surveillance culture specimens from the nares, postauricular areas, axillae, and umbilicus of infants admitted to the NICUs at a children's hospital in Taiwan were obtained weekly for the detection of methicillin-resistant S aureus. All colonized and clinical isolates from each study infant with methicillin-resistant S aureus infection were genotyped with pulsed-field gel electrophoresis, with Sma1 digestion, and compared.

RESULTS

A total of 783 infants were included in this study. Methicillin-resistant S aureus colonization was detected for 323 infants during their NICU stays, with detection with the first 2 samples for 89%. Nares and umbilicus were the 2 most common sites of initial colonization. Methicillin-resistant S aureus colonization was associated significantly with premature birth (< or = 28 weeks) and low birth weight (< or = 1500 g), and infants with colonization had a significantly higher rate of methicillin-resistant S aureus infection, compared with those without colonization (26% vs 2%). Methicillin-resistant S aureus colonization was noted for 84 of 92 infants with methicillin-resistant S aureus infections. Of the 68 episodes with previous colonization and isolates available for genotyping analysis, colonized and clinical isolates were indistinguishable in 63 episodes, highly related in 2 episodes, and distinct in 3 episodes.

CONCLUSIONS

More than 40% of the hospitalized infants were colonized with methicillin-resistant S aureus during their stay in methicillin-resistant S aureus-endemic NICUs; this was associated significantly with methicillin-resistant S aureus infection. Most infants with methicillin-resistant S aureus infections had previous colonization with an indistinguishable strain.

Pseudomonas aeruginosa otochondritis complicating localized cutaneous leishmaniasis: prevention of mutilation by early antibiotic therapy

A patient with an ulcerated cutaneous leishmaniasis of the pinna had suppurative otochondritis after a first unsuccessful course of treatment with meglumine antimoniate. Although the Leishmania ulceration healed after a second course of meglumine antimoniate, and despite three oral dicloxacillin or pristinamycin courses, the otochondritis extended and an abscess developed. Pus from the abscess revealed a pure culture of Pseudomonas aeruginosa. Five days of oral ciprofloxacin plus rifampin led to a marked improvement. The P. aeruginosa isolate was sensitive to ciprofloxacin but fully resistant to rifampin. Healing with minimal mutilation was obtained at the end of a six-week course of multiple antibiotic therapy. Pseudomonas aeruginosa otochondritis was a co-factor of cartilage mutilation in this patient. Thus, infection with P. aeruginosa should be promptly treated when present in tender cutaneous or mucosal leishmaniasis lesions near cartilaginous areas.

POTENTIAL PATHOGENS CARRIED BY SPANISH IBEX (CAPRA PYRENAICA HISPANICA) IN SOUTHERN SPAIN

The Spanish ibex (Capra pyrenaica hispanica) population of southern Spain was surveyed for potential pathogens associated with the conjunctiva, external ear canal, as well as reproductive and upper respiratory tracts. We sampled 321 ibex (131 adult males, 100 adult females, and 90 yearlings); these included 271 apparently healthy animals and 50 that were naturally infected with Sarcoptes scabiei. A total of 688 bacterial isolates were identified (377 gram-negatives, 225 gram-positives, and 86 Mycoplasma spp.); sex, age, location, infection with S. scabiei, and disposition of the animal (free-ranging versus captive) were evaluated as risk factors for infection. Infections with Mycoplasma agalactiae and Mycoplasma arginini were associated with age, having a higher frequency of isolation in young animals. With Escherichia coli, Mannheimia haemolytica, Pasteurella multocida biotype A, and Staphylococcus aureus, significantly higher isolation rates were associated with adults. The isolation frequency for E. coli was higher in females, whereas Moraxella bovis isolations were mostly associated with males. The presence of mange increased the risk of infection with both Streptococcus equi subsp. zooepidemicus and M. haemolytica. The geographic origin of sampled animals was related to the isolation of Branhamella ovis, M. agalactiae, and all Pasteurella sp. Isolations of M. haemolytica, P. multocida biotype A, E. coli, and B. ovis were more prevalent in samples from free-ranging rather than captive animals. Of the gram-positive bacteria, S. aureus represented the predominant species isolated from nasal, vaginal, and ocular samples. Mycoplasma agalactiae and M. arginini were the predominant Mycoplasma spp., and both were associated most often with the external ear canal. The most frequently isolated gram-negative bacteria included E. coli, M. haemolytica, P. multocida biotype A, and B. ovis. Isolation rates of gram-negative species varied by source. In nasal samples, M. haemolytica and P. multocida biotype A were isolated most frequently, whereas in ocular and vaginal samples, B. ovis and E. coli, respectively, were most frequently isolated.

Occurrence and Population Size of Malassezia spp. in the External Ear Canal of Dogs and Cats Both Healthy and with Otitis

Malassezia yeasts are commensal organisms of human and animal skin that occasionally act as pathogens; lipid-dependent species are associated with human skin disorders. The aim of this work was to evaluate the occurrence, risk factors and population size of different species of Malassezia in the external ear canal of dogs and cats with and without otitis externa. Between 2001 and 2003, 107 healthy animals (25 cats and 82 dogs) and 123 animals with chronic otitis exteirna (48 cats and 75 dogs) were clinically examined. Sterile cotton swabs were used to collect specimens from the external ear canal and culture tests and cytological examinations were performed to detect the presence and population size of Malassezia yeasts. Malassezia yeasts were isolated from 72.9% and 40% of the cats and from 57.3% and 28.0% of the dogs, with and without otitis externa, respectively. Malassezia was frequently isolated from animals under 5 years of age. The highest prevalence of positive samples was reported in winter for cats and in autumn for dogs. Dogs with pendulous ears showed a higher incidence of infection than dogs with erect ears. More Malassezia yeasts were recovered from animals with otitis (i.e. 59.6 colony forming units - CFUs - for cats and 66.0 CFUs for dogs) than healthy animals. Out of the 413 isolates obtained from animals with and without otitis, 403 (97.6%) were identified as M. pachydermatis and 10 (2.4%) as M. globosa. A statistical evaluation of the occurrence of Malassezia yeasts in dogs and cats revealed that predisposing factors for Malassezia infections are sampling period for cats, and type of ear for dogs. The largest population of Malassezia yeasts was detected in animals with otitis, suggesting a role in the occurrence of lesions.

Malignant external otitis: treatment with prolonged usage of antibiotics and Burow's solution

Malignant external otitis is a severe infection of the external auditory canal, generally caused by Pseudomonas aeruginosa in elderly diabetics patients. We describe a case of malignant external otitis in a 63-year-old man with severe otalgia, purulent otorrhea and polypoid granulation of the external auditory canal. Local debridement, insulin treatment and 6-week intravenous antibiotic therapy with carbapemens were very effective and the granulation tissue disappeared completely. However, the patient readmitted for recurrent disease 3 weeks later, despite the oral and ear drop administration with new quinolone. No recurrence has been noted after 4-week additional treatment with intravenous carbapenems followed by 3-week treatment with Burow's solution as ear drops.

Isolation and characterization of staphylococci from external auditory meatus of dogs with or without otitis externa with special reference to Staphylococcus schleiferi subsp. coagulans isolates

Staphylococci were isolated from the external auditory meatus in 14 (48.3%) of 29 dogs affected with otitis externa (OE dogs) and 28 (68.3%) of 41 dogs without OE (non-OE dogs). Twenty-two OE isolates were identified as belonging to 12 species, and 42 non-OE isolates were identified as belonging to 13 species. The predominant species found in both OE and non-OE isolates were S. intermedius, and S. epidermidis. Thirty-eight (59.4%) of 64 isolates were resistant to one or more of the 17 antimicrobial agents tested. Resistance to PCG and ABPC was most frequent. S. schleiferi subsp. coagulans, a recent etiologic agent of canine OE, was isolated from OE and non-OE dogs. All of the 5 S. schleiferi subsp. coagulans isolates showed typical characteristics. No clear difference in the extracellular enzyme or toxin profiles, nor in the PFGE patterns, was demonstrated between the OE and non-OE isolates of S. schleiferi subsp. coagulans. A new PCR primer set specific for 16S rDNA was designed to identify strains of S. schleiferi subsp. coagulans. The amplified fragment was detected in all of the 5 isolates as well as the type strain GA 211 (=JCM 7470) and a reference strain GA 11, but was not detected in any strains of the related species, S. aureus, S. intermedius and S. hyicus. The PCR may allow a simple, rapid and precise identification of S. schleiferi subsp. coagulans, in addition to the standard tube test for free coagulase.

Prevalence of Malassezia spp. in healthy pigs

In the present study, we evaluated the occurrence of Malassezia spp. from superficial areas (ear, anus, forehead and back) in 100 healthy pigs. All cultures from anus, forehead and back were negative for Malassezia spp. A total of 73% of pigs were colonized by Malassezia yeasts in the external ear canals. We isolated only lipid-dependent species (Malassezia sympodialis 58%, Malassezia slooffiae 30%). This study evaluates the occurrence of Malassezia spp. in pigs since the taxonomic revision in 1996.

[Auricular perichondritis in adults. An evaluation-study of 12 hospitalized patients]

Perichondritis of the auricle in adults can be secondary to traumatic agents, external otitis or surgery being Pseudomona aeruginosa the bacteria more often isolated. We have performed a retrospective study of 12 hospitalized patients with that diagnosis and these following variables have been evaluated: Age, sex, personal antecedents, clinical symptoms, affected auricle, complementary explorations, treatment, evolution and stay.

Viabilidade de cepas de Malassezia pachydermatis mantidas em diferentes métodos de conservação

A manutenção de culturas de Malassezia pachydermatis em micotecas é importante para estudos retrospectivos e prospectivos. O objetivo deste trabalho foi avaliar o comportamento de Malassezia pachydermatis frente a diferentes métodos de conservação de culturas. Para tanto, após o processo de identificação, essa levedura foi estocada, por seis e nove meses, em salina e salina com óleo mineral a 28°C, bem como, em ágar Dixon, ágar Dixon acrescido de glicerol e ágar Dixon acrescido de dimetil-sulfóxido (DMSO) a -20°C. Os meios de Dixon e Dixon acrescido de glicerol foram os métodos mais adequados (p< 0,05) para manter a viabilidade das cepas, em seis e nove meses de estoque. Qualquer dos métodos utilizados foi conveniente para manutenção da positividade na prova da urease em seis meses de estocagem, sendo o ágar Dixon e o ágar Dixon acrescido de glicerol, os melhores (p< 0,05) para nove meses. Portanto, para a recuperação e manutenção das características de Malassezia pachydermatis, recomenda-se o emprego do meio de Dixon ou do meio de Dixon acrescido de glicerol.

[Effects of high-pressure argon-containing gaseous compositions on operators' rhinopharynx and external ear microflora and its reactivity to antibiotics]

Earlier investigations revealed an important microbiological feature of the human in hyperbaric environment--linear progressive unbalance in the opportunistic and commensal ratio within the main biotopes. Change in the gaseous environment may influence the activity of infectious agents. Purpose of our investigation was to study effects of argon-containing gaseous compositions on the rhinopharynx and external ear microflora in operators, and its reactivity to antibiotics. Attempted was quantification of the operators' aerobic microflora exposed for 6, 7 and 18 days to argon-containing gaseous compositions (normoxic and hypoxic) under an elevated pressure (0.15-0.5 MPa). Evaluated was also susceptibility of the human microflora to antibiotics of the basic chemical classes under these conditions. The argon-containing gaseous compositions in the above pressure range did not have any specific effects on the ratio of aerobic gram-negative bacilli and staphylococci; neither they created selective advantages to any of the groups of microorganisms under study. It was found additionally that long-duration exposure in the argon-containing gaseous environment (6, 7 and 18 days) gave rise to cultures with the signs of hospitalism (e.g., high index of multiple drug resistance). Potentiality of infection development in dwelling modules with argon-containing gaseous environment and proliferation of polyresistant strains point to the necessity to design a respective preventive system.

The Cytology of the External Ear Canal in the Normal Dog and Cat

This study was conducted on 50 normal dogs and 52 normal cats in order to characterize the normal cytological findings in specimens taken from the vertical ear canal by swabbing. Yeast were detected in 96% of the dogs and 83% of the cats. Gram-positive cocci were found in 42% of the dogs and 71% of the cats. Rods were not seen. In dogs, the median numbers per high-power microscopic field (400x magnification) for yeast, cocci and keratinocytes were 0.2, 0 and 3.9, respectively. In cats, the median numbers were 0.2, 0.3 and 8, respectively. Nucleated keratinocytes were occasionally observed in both species, and should not be mistaken for a pathological process (parakeratotic hyperkeratosis).

Factors associated with the prevalence of Malassezia species in the external ears of cattle from the state of Minas Gerais, Brazil

Swabs collected from the external ears of 942 cattle, including both European and zebu breeds, were used to evaluate the epidemiology of Malassezia species. High numbers of Malassezia isolates were significantly associated with maturity of the animals and with diagnosed otitis. In healthy animals, a particularly low prevalence of the genus was found in Holstein cows, especially in the summer months, a finding perhaps correlating with the open, air-exposed ears of this breed. Pendutlous-eared zebu breeds and hybrids had higher levels of colonization, although this effect was more pronounced in humid regions, and was least in the dry north and west of the state. The most common species seen was M. sympodialis, which accounted for 47.1% of isolates from healthy cattle and 39.1% from cattle with otitis. In cattle with otitis sampled in summer, we found that the relatively thermotolerant M. sympodialis made up 80.8% of isolates. By contrast, during the winter the less thermotolerant M. globosa was the most common species from otitis, making up 56% of the isolates. Humidity and temperature may be the main factors explaining the epidemiology of Malassezia diseases and colonizations in both animals and humans.

Quantity of aerobic bacteria in the bony portion of the external auditory canal of children

OBJECTIVE

the human external auditory canal (EAC) hosts a commensal bacterial flora of mainly non-pathogens, but bacterial pathogens may also be present. The latter are important in the aetiopathogenesis of external otitis and middle ear cholesteatoma with discharge. The purpose of this study was to quantify the bacteria normally harboured in the healthy EAC and on a well-defined region of the cavum conchae (CC) of children.

METHODS

bacterial samples were collected from the CC and bony portion of the EAC of 32 children (18 boys, 14 girls; median age 5 years). Prior to sampling, the EACs were either left untreated, anaesthetized with Bonain's solution, or washed with 70% alcoholic solution. The samples were incubated at 37 degrees C and evaluated regarding bacterial species and number.

RESULTS

the predominant bacterial non-pathogens were coagulase-negative Staphylococci and coryneforms (diphtheroids) and pathogens Staphylococcus aureus and Pseudomonas aeruginosa. Total bacterial counts of the CC ranged between 2 x 10(3) and 4.6 x 10(4) CFU/cm(2) (median value 7 x 10(3); n = 14). Total bacterial counts from the bony portion of the EAC ranged between 0 and 5.7 x 10(7) CFU/EAC (median value 8 x 10(3); n = 32). Pre-treatment of the EACs with Bonain's solution containing the highly bactericidal substance phenol or with 70% alcoholic solution did not sterilize the EAC.

CONCLUSIONS

small numbers of bacterial non-pathogens (and sometimes pathogens) are found in the EAC of children. Neither phenol nor 70% alcoholic solution can inhibit or eradicate all these microorganisms.

[Perichondritis caused by high ear piercing. Therapeutic and legal aspects]

Three cases of auricular perichondritis caused by infection with Pseudomonas aeruginosa are described to draw attention to the high incidence of piercing-related infections and the risk of structural deformities to the outer ear. Various therapies and outcomes are described and current Danish legislation is highlighted.

[Ear piercing and auricular chondritis caused by Pseudomonas aeruginosa]

This paper describes five patients who had undergone transcartilaginous ear piercing and were infected with Pseudomonas aeruginosa, which led to perichondrial abscess. Early treatment of chondritis with aggressive surgical therapy combined with relevant antibiotics results in good healing and a minimal loss of cartilage. The literature review and cases presented show that piercing is not harmless and that regulation of the piercing business would seem to be desirable.

Comparison of two sampling techniques to assess quantity and distribution of Malassezia yeasts on the skin of Basset Hounds

Cytological examination using the tape-strip technique and fungal culture using contact plates with modified Dixon's medium were compared to evaluate the carriage of Malassezia yeasts on four cutaneous sites (left pinna, umbilical region, axilla and perianal area) in adult Basset Hounds. Twenty animals were included in the study. High numbers of Malassezia were isolated from at least one area in 100% of the animals. The frequencies of isolation and population sizes differed significantly according to anatomical location. They were greater on the pinna, followed by the umbilical area, axilla and perianal area. Fungal culture was more sensitive than cytology for the isolation of Malassezia yeasts. Frequencies of isolation were greater using this method, but population sizes were constantly smaller than with cytology.

Frequency of isolation and antimicrobial susceptibility patterns of Staphylococcus intermedius and Pseudomonas aeruginosa isolates from canine skin and ear samples over a 6-year period (1992-1997)

Staphylococcus intermedius (S. intermedius) was isolated from 88.6% and 49.4% of skin and ear samples, respectively, during the years 1992 through 1997, and frequency of isolation remained unchanged. More than 95% of all S. intermedius isolates were susceptible to cephalothin and oxacillin, providing support for empirical treatment of canine skin and ear infections with cephalexin. Pseudomonas aeruginosa (P. aeruginosa) was isolated from 7.5% and 27.8% of skin and ear samples, respectively. The frequency of isolation from skin samples increased over the study period. Because of multidrug-resistant profiles for P. aeruginosa isolates, especially for ear isolates, empirical treatment of P. aeruginosa infections is not advisable.

A semiquantitative cytological evaluation of normal and pathological samples from the external ear canal of dogs and cats

Numbers of desquamated epithelial cells, yeast cells and bacterial organisms were counted in samples collected from the external ear canal of 37 normal dogs and 16 normal cats, and from 24 dogs and 22 cats with otitis externa. The aims of the study were to establish quantitative reference ranges and to correlate these data with the clinical status of the dogs and cats. Numbers of yeast cells and bacterial organisms were significantly increased in dogs (P = 0.05; P = 0.0001) and cats (P = 0.0001; P = 0.0001) with otitis externa, and in most cases high counts were correlated with clinical signs. Mean Malassezia counts per high-power dry field of > or = 5 in the dog and > or = 12 in the cat were considered abnormal. Mean bacterial counts per high-power dry field of > or = 25 in the dog and > or = 15 in the cat were considered abnormal. When used to differentiate normal from inflamed external ear canals, these figures provided a low sensitivity but a specificity of > or = 95%.

Occurrence of Malassezia spp. in the external ear canals of dogs and cats with and without otitis externa

We studied the lipophilic microbiota of the external ear canals of 332 animals (264 dogs and 68 cats), with and without otitis externa, over an 11-year period from 1988 to 1999. Malassezia pachydermatis was isolated from 62.2% and 50% of dogs with and without otitis externa, respectively, and from 41.2% and 17.6% of cats with and without otitis externa, respectively. In the group of animals studied for lipid-dependent species, these yeasts were isolated from 4.5% of dogs with otitis externa and from 23.1% and 8.9% of cats with and without otitis externa, respectively. M. sympodialis and M. furfur were isolated from cats and M. furfur and M. obtusa from dogs. Our findings show that lipid-dependent Malassezia species may contribute to the etiology of otitis externa in dogs and cats.

[Dermatophytosis of the external auditory meatus]

Dermatophytosis of the external auditory meatus is believed to be a fairly rare disease. In the past three and a half years we have had seven cases of dermatophytosis in the external auditory meatus. All cases except one were associated with tinea of other lesions. Case 1: A 44-year-old man had tinea of the auricle, tinea pedis and tinea unguium. Case 2: A 14-year-old boy, the son of case 1 had no tinea elsewhere on his body, including the auricle. He scratched the auditory meatus with an earpick which his father had used. Case 3: A 62-year-old man had tinea of the auricle, tinea pedis and tinea unguium. Case 4: A 50-year-old man had tinea of the auricle, tinea pedis and tinea unguium. Case 5: A 36-year-old man had tinea of the auricle, tinea pedis, tinea unguium and tinea cruris. Case 6: A 30-year-old woman had tinea of the auricle. Case 7: A 68-year-old man had tinea of the auricle, tinea pedis, tinea unguium and tinea manuum. Endoscopic examination (except for cases 4 and 7) revealed dry cerumen from cartilaginous to bony region of the external auditory meatus. Direct examination using KOH method of the cerumen in all cases demonstrated numerous fungal elements. Fungal cultures identified Trichophyton rubrum except for cases 3 and 6. All cases were successfully treated with oral itraconazole or terbinafine. We suggest that tinea of the external auditory meatus is frequently associated with that of the auricle.

Influence of human wet cerumen on the growth of common and pathogenic bacteria of the ear

The available data on the effect of human wet cerumen on bacterial growth are not conclusive. Nevertheless it is widely accepted that cerumen has a bactericidal effect. In this study the activity of human wet cerumen on bacterial growth was assessed by applying cerumen suspensions to bacterial cultures. Bacterial counts were performed before and after application of cerumen suspensions. A total of 383 assays was carried out with 73 pools of cerumen that were tested against cultures of Staphylococcus aureus, Staphylococcus epidermidis, Corynebacterium spp., Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Serratia marcescens. An increase in growth occurred much more frequently than a decrease in growth in almost every microrganism tested, with the mean increase percentage being much higher than the mean decrease percentage, except in the case of S. aureus. The largest average growth increase was obtained with E. coli. The largest average decrease in bacterial growth was recorded with S. marcescens. Our study does not support the conception of a decrease in bacterial growth produced by humen wet cerumen. In vitro, the most observable effect was in fact an increase in microbial growth.

Bilateral aural hyalohyphomycosis in sable antelope (Hippotragus niger)

Three juvenile sable antelope (Hippotragus niger) were diagnosed with bilateral aural hyalohyphomycosis based on histopathology. All three animals were suspected to be immunodeficient based on low IgG levels determined using the zinc sulfate turbidity test. The serum and hepatic copper levels of one animal were below the bovine reference range. Clinical signs in the three animals included bilateral ventral deviation of the pinnae with multifocal subcutaneous aural tumefaction and poor body condition. Numerous septate, nonpigmented fungal hyphae were found within the auricular cartilage, dermis, and subcutaneous granulomas. No significant fungal agents were isolated by culture, and no signs of systemic fungal dissemination were identified except for a concurrent fungal rhinitis in one animal.

[Imaging and traumatic, inflammatory and neoplastic pathologies of the external and middle ear]

CT and MR imaging have a growing place in the assessment of pathologic ear. Nowadays, Ultra-high resolution CT scan is the method of choice to detect traumatic, tumoral or inflammatory lesions. MR imaging is frequently proceed in second place after CT evaluation. MR remains essential to evaluate the extension of malignant tumor of the temporal bone in particular to the fatty tissues or cerebral parenchyma. Our aim is to present the radiologic semeiology of external and middle ear pathologies, precising for each one the role of CT and MR imaging.

An unusual case of Pneumocystis carinii presenting as an aural mass

Extrapulmonary involvement of organs with the protozoan Pneumocystis carinii is rare. We describe a case of Pneumocystis carinii presenting as an erosive aural mass in a young male patient with acquired immunodeficiency syndrome. As far as the authors are aware such an example has never been described in a British journal and is the first case worldwide where otic pneumocystosis has extended into the middle cranial fossa. We also present a review of the literature on otological manifestations of Pneumocystis carinii.

[Congenital cholesteatoma of temporal bone]

On the basis of 72 reports in the literature and own case, the authors described new theories on the pathogenesis of congenital cholesteatoma. They present differentiation of congenital and acquired cholesteatoma by cyto-, histochemical and immunohistochemical methods. They discuss methods of diagnosis and therapy. Attention has been called to diagnosis by CT and MR examinations.

Specificity of infection-induced immunity among Borrelia burgdorferi sensu lato species

The specificity of infection-induced immunity in mice infected with cultured or host-adapted Borrelia burgdorferi sensu lato, the agent of Lyme disease, was examined. Sera obtained from mice following infection with high and low doses of cultured B. burgdorferi sensu stricto, transplantation of infected tissue (host-adapted spirochetes), or tick-borne inoculation all showed protective activity in passive immunization assays. Infection and disease were similar in mice infected with cultured spirochetes or by transplantation. Thus, the adaptive form of inoculated spirochetes did not influence the immune response during active infection. Mice infected with B. burgdorferi sensu stricto and then cured of infection with an antibiotic during early or late stages of infection were resistant to challenge with high doses of homologous cultured spirochetes for up to 1 year. In contrast, actively immune mice infected with different Borrelia species (B. burgdorferi sensu lato, B. burgdorferi sensu stricto cN40, Borrelia afzelii PKo, and Borrelia garinii PBi) and then treated with an antibiotic were resistant to challenge with cultured homologous but not heterologous spirochetes. Similar results were achieved for actively immune mice challenged by transplantation and by passive immunization with sera from mice infected with each of the Borrelia species and then challenged with cultured spirochetes. Arthritis and carditis in mice that had immunizing infections with B. afzelii and B. garinii and then challenged by transplantation with B. burgdorferi sensu stricto were equivalent in prevalence and severity to those in nonimmune recipient mice. These results indicate that protective immunity and disease-modulating immunity that develop during active infection are universal among species related to B. burgdorferi sensu lato but are species specific.

Clinical evaluation and surgical management of congenital preauricular fistulas

PURPOSE

The retrospective investigation evaluated the clinical data on patients with a preauricular fistula with respect to demographic factors, symptoms, preoperative diagnosis, and surgical therapy. Follow-up studies served to critically assess the outcome of the operations.

PATIENTS AND METHODS

The records of 62 patients were studied. Patients were divided into two groups: those operated on for the first time for a preauricular fistula and those operated on for a recurrence. Controlled follow-up was performed by means of a standardized questionnaire filled out by both the patients' physicians and the patients themselves.

RESULTS

The mean age of patients operated on for the first time was 16 years, and that of patients operated on for a recurrence was 22 years. Although the overall rate of recurrence was 21%, it differed widely between groups (14% in first operations and 42% in patients operated on for the first time for a recurrence). These figures are within the lower range of the recurrence rates previously reported. Serious side effects, such as persistent damage to the facial nerve, were not observed.

CONCLUSIONS

Operative management of a preauricular fistula is a treatment with few side effects that should be offered to each patient with such a malformation. Because the first operation is decisive for the further course of the condition, surgery should be performed under optimum conditions to avoid recurrence.

Auricular chromoblastomycosis caused by Rhinocladiella aquaspersa

An unusual case of chromoblastomycosis localized in the ear and caused by R. aquaspersa is presented. The patient was a 60-year-old male urban resident, who had had the disease for 5 years. The lesion was darkly pigmented, infiltrative and crusty. Sclerotic cells were seen on direct examinations and the fungus was recovered in culture and identified on the basis of the characteristic sporulation. Itraconazole therapy at a dose of 200 mg day-1 for 7 months produced complete healing.

New combination for the therapy of canine otitis externa. I. Microbiology of otitis externa

In order to compound a new drug combination against canine otitis externa (OE), 515 dogs affected with OE were subjected to physical examination and microbiological analysis of their ear exudates. OE was erythematous-ceruminous in 83 per cent and suppurative in 17 per cent of the patient material. Erythematous-ceruminous inflammations were characterised by severe pruritus and accumulation of brownish, greasy cerumen in the auditory canal. The yeast Malassezia pachydermatis was isolated from the ears of 76 per cent of the dogs, often in combination with Staphylococcus intermedius bacteria. M pachydermatis showed the most sensitivity, in decreasing order of efficacy, to ketoconazole, econazole, clotrimazole, miconazole and nystatin. S intermedius isolates were most sensitive to amoxycillin-clavulanic acid, enrofloxacin, cephalexin and gentamicin. The microorganism most frequently isolated from dogs with suppurative OE was Pseudomonas aeruginosa; in some cases Proteus, Streptococcus and Pasteurella were also isolated. The P aeruginosa isolates showed the highest sensitivity to gentamicin, polymyxin B and tobramycin.

Skin smears in leprosy: is reduction in number of sites justified?

An analysis of 377 sets of positive skin smears of leprosy patients was done to determine the minimum sites needed to detect all smear positive leprosy patients. A combination of earlobe and a selective site could pick up 95.5% of the patients. An additional smear from the forehead increased the sensitivity of 97.7%. The results suggest that the sites for skin smears may be reduced to a combination of the earlobe and one selective site smear from a skin lesion to be able to detect most smear positive leprosy patients.

Role of the eastern chipmunk (Tamias striatus) in the epizootiology of Lyme borreliosis in northwestern Illinois, USA

The role of the eastern chipmunk (Tamias striatus) in the epizootiology of Lyme borreliosis was evaluated in Castle Rock State Park, Illinois (USA), an enzootic region, from June to August 1993. Prevalence, intensity, and molting rate of immature Ixodes scapularis were determined for chipmunks, white footed mice (Peromyscus leucopus), and raccoons (Procyon lotor). Chipmunks were the primary host for I. scapularis nymphs and an important secondary host for I. scapularis larvae. Based upon ear punch biopsy analysis, B. burgdorferi prevalence in chipmunks was similar to that of mice in August and greater than that of mice in June and July. Thus we propose that chipmunks are the primary source of B. burgdorferi infection for I. scapularis nymphs and an important secondary source of infection for larvae.

Antibiotic treatment in mice infected with Japanese Borrelia garinii: efficacy of ceftriaxone for eradicating the infection induced by Ixodes persulcatus tick bites

We compared the efficacy of three antibiotics (ceftriaxone, erythromycin and clarithromycin) against Borrelia garinii infection in mice. The nymphal ticks of Ixodes persulcatus infected with the strain JEM6 of Japanese B. garinii were allowed to feed on female C3H mice. The mice were treated with each of the antibiotics for 5 consecutive days 1, 3, or 7 weeks after tick detachment. The doses of antibiotics per day were as follows: 5 mg intraperitoneal injection of ceftriaxone, 2 mg intraperitoneal injection of erythromycin and 1 mg peroral administration of clarithromycin. The infection status in treated mice was monitored by culturing their earlobes, hearts and urinary bladders in BSK II medium. Ceftriaxone eliminated borreliae completely; however, a recurrence of infection was observed in mice treated with erythromycin and clarithromycin.

Comparison of media and conditions of incubation for the quantitative culture of Malassezia pachydermatis from canine skin

Fifty-five swab-wash specimens from dogs were cultured at 32 degrees C on Sabouraud's dextrose agar either with or without 1 per cent Tween 80. Ushijima's medium A and modified Dixon's and Leeming's media. The counts of Malassezia pachydermatis were not significantly different after three or seven days of incubation. Colony counts on contact plates were significantly greater after incubation for seven days on Sabouraud's dextrose (P < 0.001) and modified Dixon's agars (P < 0.05) than after three days at 26 degrees C, but not at 32 degrees C. Counts on Sabouraud's or modified Dixon's agars after incubation at 32 degrees C and 37 degrees C were not significantly different. When compared with aerobic culture, an atmosphere containing 5 to 10 per cent carbon dioxide significantly (P < 0.01) increased the frequency of isolation and colony counts on Sabouraud's dextrose agar but not on modified Dixon's agar.

Prevalence of Lyme disease spirochetes in Ixodes persulcatus and wild rodents in far eastern Russia

Borrelia spirochetes were isolated from the adult ixodid tick (Ixodes persulcatus) in three areas of far eastern Russia, namely, Khabarovsk, Vladivostok, and Yuzhno-Sakhalinsk. Borrelia infective rates of ticks in those areas were 24.5, 41.4, and 25.1%, respectively (total rate was 26.6%). Spirochetes were also isolated from the tissues of small mammals captured at Khabarovsk (infective rate was 20.8%). Samples were classified by rRNA gene restriction fragment length polymorphism (RFLP) analysis. The isolated spirochetes from ticks were classified mainly RFLP ribotype group IV (B. garinii), followed by groups II (B. garinii), III (B. afzelii), and V (B. garinii), showing that B. garinii is a dominant species among them. Both B. garinii and B. afzelii were also found in rodents, and multiple infections with those two species were observed in some rodents. B. burgdorferi sensu stricto (group I) was not isolated from either ticks or rodents.