Epidemiological study of dogs with otitis externa in Cape Breton, Nova Scotia

From May 2008 to December 2013, 320 cases of otitis externa were diagnosed among 2012 dogs undergoing routine physical examinations at Celtic Creatures Veterinary Clinic, Sydney River, Nova Scotia for a diagnosis frequency of 15.9% [95% confidence interval (CI): 14.3% to 17.6%]. Twenty-four percent of these dogs exhibited 1 or multiple recurrences despite initial treatment with topical antimicrobial/anti-inflammatory solutions. The frequency of diagnosis was significantly higher in breeds with pendulous ears, but was not affected by ear hairiness. There were no seasonal patterns in the frequency of diagnosis. In clinical examination of 60 dogs with otitis externa, bacteria were evident in 47% of infections. Of 10 genera cultured, Staphylococcus spp. and diptheroids were most common. In this study, analysis of clinical records provided insights into the local prevalence of otitis externa and the efficacy of treatment in routine clinical situations.

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.

Species composition of Malassezia yeasts in dogs in Slovakia

Malassezia (M.) pachydermatis is the lipophilic yeast, which is normally present on the skin and in the ear canal of dogs but under certain conditions it may cause dermatitis and otitis. There is less known about the occurrence of lipid-dependent Malassezia species in dogs. The aim of this study was to detect whether lipid-dependent yeasts are part of the normal microflora in dogs. Two groups of animals were selected for comparison. The group of healthy dogs contained samples of 118 individuals and the group of dogs with cutaneous lesions or otitis externa comprised 328 dogs. The isolates of Malassezia were identified by using genotypic methods that allow the precise identification. M. pachydermatis was the most frequently isolated species in this study (121 isolates). Only four isolates were identified as M. furfur and one isolate was identified as M. nana.

Frequency, Body Distribution, and Population Size of Malassezia Species in Healthy Dogs and in Dogs with Localized Cutaneous Lesions

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%).

Outbreak of Methicillin-Resistant Staphylococcus aureus Colonization and Infection in a Neonatal Intensive Care Unit Epidemiologically Linked to a Healthcare Worker With Chronic Otitis

Objective.

To describe the investigation and interventions necessary to contain an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection in a neonatal intensive care unit (NICU).

Design.

Retrospective case finding that involved prospective performance of surveillance cultures for detection of MRSA and molecular typing of MRSA by repetitive-sequence polymerase chain reaction (rep-PCR).

Setting.

Level III NICU in a tertiary care center.

Participants.

Three neonates in a NICU were identified with MRSA bloodstream infection on April 16, 2004. A point prevalence survey identified 6 additional colonized neonates (attack rate, 75% [9 of 12 neonates]). The outbreak strain was phenotypically unusual.

Interventions.

Cohorting and mupirocin therapy were initiated for neonates who had acquired MRSA during the outbreak. Contact precautions were introduced in the NICU, and healthcare workers (HCWs) were retrained in cleaning and disinfection procedures and hand hygiene. Noncolonized neonates and newly admitted patients had surveillance cultures performed 3 times per week.

Results.

Two new colonized neonates were identified 1 month later. HCW X, who had worked in the NICU since June 2003, was identified as having chronic otitis. MRSA was isolated from cultures of swab specimens from HCW X's ear canal and nares. HCW X was epidemiologically linked to the outbreak. Molecular typing (by rep-PCR) confirmed that the isolates from HCW X and from the neonates were more than 90% similar. Retrospective review of NICU isolates revealed that the outbreak strain was initially cultured from a neonate 2 months after HCW X began working on the unit. The epidemic strain was eradicated after removing HCW X from patient care in the NICU.

Conclusion.

An outbreak of MRSA colonization and infection in a NICU was epidemiologically linked to a HCW with chronic otitis externa and nasal colonization with MRSA. Eradication was not achieved until removal of HCW X from the NICU. Routine surveillance for MRSA may have allowed earlier recognition of the outbreak and is now standard practice in our NICU.

Recurrent malignant otitis externa with multiple cranial nerve involvement: A case report

INTRODUCTION

Necrotizing otitis externa is a rare but conditionally fatal infection of external auditory canal with extension to deep soft tissue and bones, resulting in necrosis and osteomyelitis of the temporal bone and scull base. This condition is also known as malignant otitis due to an aggressive behavior and poor treatment response. Early diagnosis of malignant otitis is a difficult challenge. We present an illustrative case of necrotizing otitis externa and suggest some strategies to avoid diagnostic and treatment pitfalls.

CASE OUTLINE

A 70-year-old patient presented with signs of malignant otitis externa, complicated by peripheral facial palsy. Adequate diagnostic and treatment procedures were performed with clinical signs of resolution. The recurrence of malignant infection had presented three months after previous infection with multiple cranial nerve neuropathies and signs of jugular vein and lateral sinus thrombosis. An aggressive antibiotic treatment and surgery were carried out, followed by substantial recovery of the patient and complete restoration of cranial nerves’ functions.

CONCLUSION

Necrotizing otitis externa is a serious condition with uncertain prognosis. The suspicion of malignant external otitis should be raised in cases of resistance to topical treatment, especially in patient with predisposing factors. Evidence-based guideline for necrotizing otitis externa still doesn’t exist and treatment protocol should be adjusted to individual presentation of each patient.

Otite externe maligne à Candida Albicans

L’otite externe maligne est une ostéomyélite de la base du crane. Le Pseudomonas aeruginosa est le germe le plus incriminé. Cependant l’origine fongique n’est pas rare. Patiente âgée de 80 ans avait présenté une otalgie gauche persistante depuis deux mois malgré un traitement bien conduit. L’examen otologique mettait en évidence des signes inflammatoires au niveau du pavillon, une sténose du conduit avec des granulomes, et otorrhée d’allure purulente. Le scanner montrait un comblement otomastoïdien, un processus inflammatoire extensif des tissus pré et rétro-auriculaire et une lyse du tympanal. Vu l’absence d’amélioration un examen mycologique a été réalisé et qui a révélé la présence de Candida Albicans. Les cas d’otite externe maligne à Candida Albicans sont rarement rapportés. L’origine fongique doit être suspecté devant la négativité des prélèvements bactériologiques et la non amélioration malgré un traitement antibiotique bien conduit, et confirmée par des prélèvements mycologiques parfois multiples. L’otite externe maligne à Candida Albicans est une infection rare potentiellement mortelle.

[Efficacy of Dioxidine antimicrobial preparation for the treatment of inflammatory diseases of the external and middle ear]

In this article, the comparative analysis of the clinical efficacy of drugs for local therapy in patients with acute external otitis, acute purulent otitis media and exacerbation of chronic suppurative otitis media is presented. The results of the clinical study, dynamic bacteriological investigation confirmed the high efficacy, safety and good tolerance of dioxidine in treatment of external and middle ear infections.

Outcome predictors of treatment effectiveness for fungal malignant external otitis: a systematic review

The aim of this review is to summarise literature data on clinical aspects and traditional management of fungal malignant external otitis (FMEO), and to identify potential predictive factors of positive treatment outcome. Articles were initially selected based on their titles or abstracts. Full articles were then retrieved and further scrutinised according to predetermined criteria. Reference lists of selected articles were searched for any missed publications. The selected articles were methodologically evaluated. Of an initial 143 references, 14 were selected that focalised on the management of FMEO. The majority of studies demonstrated a correlation between treatment effectiveness, assessed as symptom resolution, and clinical and management variables: abstention from surgical debridement, absence of facial palsy, Aspergillus spp. as causative pathogen and absence of imaging findings at diagnosis and follow-up. The effectiveness of FMEO treatment depends on the assessment of cranial nerve state, the causative pathogen and imaging findings. Above all, absence of facial nerve palsy, Aspergillus spp. and absence of radiological signs at diagnosis and during follow-up correlate with symptom resolution. The fact that conservative treatment may be associated with a better outcome than surgical debridement could purely reflect that patients with more aggressive and advanced illness required debridement, whereas milder disease was treated conservatively. Thus, caution should be advised in the interpretation of data due to the need for further trials on the topic.

Malignant otitis externa in a healthy non-diabetic patient

A healthy 60-year-old male was initially treated for external otitis, and subsequently received multiple surgeries including abscess drainage, temporal bone debridement, canaloplasty of the external auditory meatus, and fistula excision and was treated with numerous antibiotics at another hospital over a 1-year period. He was seen at our hospital on February 14, 2014 with a complaint of a non-healing wound behind the left ear and drainage of purulent fluid. He had no history of diabetes mellitus or compromised immune function. Computed tomography (CT) and magnetic resonance imaging (MRI) studies at our hospital showed osteomyelitis involving the left temporal, occipital, and sphenoid bones, the mandible, and an epidural abscess. Routine blood testing and tests of immune function were normal, and no evidence of other infectious processes was found. He was diagnosed with malignant otitis externa (MOE). Bone debridement and incision and drainage of the epidural abscess were performed, and vancomycin was administered because culture results revealed Corynebacterium jeikeium, Corynebacterium xerosis, and Enterococcus faecalis. MOE should be considered in healthy patients with external otitis who fail initial treatment.

Technetium-99m (⁹⁹mTc)-labelled sulesomab in the management of malignant external otitis: is there any role?

We report two cases of malignant external otitis (MEO) evaluated with Technetium-99m((99m)Tc)-labelled sulesomab. Two patients affected by MEO are presented, together with a literature review. Both patients were studied with clinical examination, ear discharge culture, radiological imaging, blood exams, (99m)Tc Sulesomab, and treated with antibiotic therapy. (99m)Tc-Sulesomab would appear to be an useful tool for diagnosis and follow-up of MEO, highlighting the site and extension of the inflammatory process, and evaluating course and treatment efficacy. (99m)Tc-Sulesomab shows promise as a rapid, effective and safe imaging agent for treatment response evaluation and follow-up of patients with MEO. Further studies are warranted to validate the inclusion of (99m)Tc-Sulesomab scan in the imaging follow-up of patients with MEO.

[Fungus culture of the ear discharge and therapeutic effects in 60 outpatients with otitis externa]

OBJECTIVE

To assess the diagnosis and therapeutic effects for fungal otitis externa by clinical symptoms, endoscopic findings, and fungus culture of the ear discharge.

METHOD

Sixty outpatients diagnosed with otitis externa were enrolled in the study. All patients were treated with a thorough debridement of the ear and one antifungal medication regimens (compound resorcinol solution) in case of a positive fungus culture. One subgroup of patients treated with daub glycerol during 2 weeks of follow-up.

RESULT

Positive cultures were found in 42 cases. The efficacy was observed in all patients even in those who received only ear endoscopy.

CONCLUSION

Fungal otitis externa could be easily diagnosed by ear endoscopy. A thorough debridement of the ear and utility of compound resorcinol solution is an easy and effective approach for treatment of fungal otitis externa.

An Outbreak ofPseudomonas aeruginosaPneumonia and Bloodstream Infection Associated With Intermittent Otitis Externa in a Healthcare Worker

Objectives:

To investigate an outbreak ofPseudomonas aeruginosapneumonia and bloodstream infection among four neonates, determine risk factors for infection, and implement preventive strategies.

Design:

Retrospective case finding; prospective surveillance cultures of patients, personnel, and environmental sites; molecular typing by pulsed-field gel electrophoresis; and a matched case-control study.

Patients and Setting:

Neonates in the level-III neonatal intensive care unit of a tertiary-care pediatric institution.

Interventions:

Cohorting of patients with positive results forP. aeruginosa, work restrictions for staff with positive results, implementation of an alcohol-based hand product, review of infection control policies and procedures, and closure of the unit until completion of the investigation.

Results:

Seven (4%) of 190 environmental cultures and 5 (3%) of 178 cultures of individual healthcare workers' hands grewP. aeruginosa. All four outbreak isolates and one previous bloodstream isolate were genotypically identical, as were theP. aeruginosaisolates from the hands and external auditory canal of a healthcare worker with intermittent otitis externa. Four of 5 case-patients versus 5 of 15 matched control-patients had been cared for by this healthcare worker (P= .05). The healthcare worker was treated and no further cases occurred.

Conclusions:

These findings suggest that a healthcare worker with intermittent otitis externa may have caused this cluster of fatalP. aeruginosainfections, adding the external ear to the list of colonized body sites that may serve as a source of potentially pathogenic organisms.

The joint in vitro action of polymyxin B and miconazole against pathogens associated with canine otitis externa from three European countries

BACKGROUND

Canine otitis externa, an inflammation of the external ear canal, can be maintained and worsened by bacterial or fungal infections. For topical treatment, combinations of anti-inflammatory and antimicrobial ingredients are mainly used.

HYPOTHESIS/OBJECTIVES

This study was conducted to elucidate the in vitro activity of polymyxin B and miconazole against clinical bacterial isolates from three European countries, to investigate possible differences in sensitivity and to assess drug interactions.

ANIMALS

Seventeen strains of Escherichia coli, 24 strains of Pseudomonas aeruginosa, 24 strains of Proteus mirabilis and 25 strains of Staphylococcus pseudintermedius from dogs with diagnosed otitis externa had been isolated in Germany, France and Italy.

METHODS

Drug activities were evaluated by minimal inhibitory concentration (MIC) and minimal bactericidal concentration. The potentiation of polymyxin B plus miconazole was calculated using the fractional inhibitory concentration index (FICI). An FICI ≤0.5 defined synergy. Furthermore, geographical variations in the FICI and MIC were assessed by statistical analysis.

RESULTS

Bacterial susceptibilities were comparable in different European countries, because there were no significant MIC and FICI variations (P > 0.05). As a single agent, polymyxin B had bactericidal activity against most E. coli and P. aeruginosa strains and, in higher concentrations, against S. pseudintermedius strains. Miconazole was bactericidal against all Staphylococcus strains. Synergy was demonstrated against strains of E. coli and P. aeruginosa (FICI = 0.25 and 0.50, respectively), whereas overall there was no interaction against S. pseudintermedius strains (FICI = 1.25). Proteus mirabilis strains were not inhibited by each of the drugs individually or by their combination.

CONCLUSIONS AND CLINICAL IMPORTANCE

In vitro synergy of polymyxin B and miconazole against E. coli and P. aeruginosa isolates indicates a rationale for applying both agents in combination to treat otitis externa when infected with these types of bacteria.

Otitis externa following aural irrigation linked to instruments contaminated with Pseudomonas aeruginosa

BACKGROUND

The incidence of acute otitis externa, an infection of the external auditory canal, in general practitioners' (GP) practices in The Netherlands is about 14 per 1000 patients per year. In early 2010, one of the authors noted that some of the otitis externa patients in his GP practice had undergone cerumen removal by ear syringing a few weeks earlier. Bacterial cultures of samples taken from the instruments used showed contamination of an ear syringe by Pseudomonas aeruginosa. From then on, P. aeruginosa isolates from patients' ears were stored in the laboratory.

AIM

It was assessed whether cross-contamination with P. aeruginosa between patients in the same GP practice could occur through the use of contaminated ear lavage instruments.

METHODS

From 17 GP practices, the otolaryngology Outpatient Department and the Out-of-Hours GP Service, instruments used for examining and cleaning the outer ear were swabbed. Strains of P. aeruginosa cultured from the instruments were genotyped together with isolates of patients registered in the same practice.

FINDINGS

In four practices where contaminated instruments were found, genotyping showed similarity between P. aeruginosa strains isolated from a patient and the ear syringe, and/or between strains of different patients in the same practice.

CONCLUSIONS

Transmission of P. aeruginosa from ear lavage instruments to patients appears to occur with otitis externa as a result. Together with the Infection Control Unit of our hospital we have formulated recommendations for the appropriate cleaning, disinfection and storage of re-usable ear lavage instruments for the GP practices to implement.

An investigation of ear necrosis in pigs

Porcine ear necrosis was investigated in 23 conveniently chosen farms, consisting of 14 case farms and 9 control farms. Biopsies of lesions and oral swabs from pigs on 11 case farms were examined by histology and bacterial culture. All farms were visited for observations and a survey on management, housing, and the presence of other clinical signs or behavioral vices. Histological examination revealed that the lesions began on the surface and progressed to deeper layers, and that vascular damage did not appear to be the initiating cause. Spirochetes were only rarely observed in histological examination and were not cultured from biopsies and oral swabs. Staphylococcus aureus and Staphylococcus hyicus were cultured from 91% and 66% of samples, respectively. Ear biting and a humid environment were associated with ear necrosis. On some farms large numbers of pigs were affected and lesions were sometimes extensive. The condition appears to be an infectious disease beginning on the surface of the skin; contributing environmental and management factors are likely.

[Comparison of four different staining methods for ear cytology of dogs with otitis externa]

AIM

Cytological examination is crucial for the diagnosis and classification of canine otitis externa. Staining should reveal micro-organisms as perpetuating factors of otitis externa. The aim of the study was to compare four different staining methods (Diff-Quik®, Diff-Quik® after dipping in acetone, Gram Quick stain® and a commercial rapid stain for otitis externa) for ear cytology of dogs with otitis externa and to investigate the agreement of cytology and culture.

MATERIAL AND METHODS

In a study evaluating dogs with otitis externa, five ear swabs (one for culture and four for cytology) were taken from the horizontal part of the external auditory canal of 224 affected ears and compared semi-quantitatively.

RESULTS

Diff-Quik® with and without prior dipping in acetone as well as the Gram Quick stain® displayed a high degree of agreement in the detection of micro-organisms (cocci p = 0.2366; rods p = 0.4832; yeasts p = 0.1574), while the commercial otitis rapid stain revealed significantly less micro-organisms (p < 0.001 for all comparisons). The results of the first three stains corresponded to the culture results by >  70%; the agreement was lower with the commercial otitis rapid stain. The quickest and easiest method was staining with Diff-Quik®.

CONCLUSION

Diff-Quik® with or without prior dipping in acetone and the Gram Quick stain® had a high agreement in the detection of microorganisms and can thus be considered nearly equivalent for the diagnosis of otitis externa infectiosa. The commercial otitis rapid stain is less reliable.

CLINICAL RELEVANCE

Based on this study Diff-Quik® can be recommended for the routine cytology of ear swabs. Additionally, a culture may be indicated and must be interpreted in the context of the cytology.

[Comparative characteristic of the local application of anti-inflammatory agents for the treatment of otitis externa and otitis media]

The objective of the present work was the clinical study of candibiotic exhibitic antibacterial, antimycotic, anti-inflammatory, and anesthetic properties when applied for the treatment of otitis externa and otitis media. This agent was included together with traditionally used systemic medications in the combined treatment of 26 patients. It was applied in the form of endoaural drops, transtubal administration through a catheter, and transtympanic pumping by the Politzer balloon technique (in case of perforation). In the patients with otomycosys, the preparation was used for the treatment of the external acoustic canal after the removal of fungal masses thrice daily for 1 month. Good clinical effect achieved in all the patients was manifest as the normal otoscopic picture and less frequent complaints on days 8-10 after the onset of therapy. Its maximum duration was 21 days. Positive dynamics (pain relief) was apparent within the first 2 days of the treatment. Fungal mycelium was absent after 14-16 days of the treatment in 100% of the patients initially presenting with yeast-like fungi.

[Agents of otomycosis in Manisa region, Turkey, 1995-2011]

Otomycosis, which is otitis externa caused by fungi, is common throughout the world especially in tropical and subtropical countries. However, the epidemiologic data about the etiologic agents of otomycosis in Turkey is limited. The aim of this retrospective study was to evaluate the agents of otomycosis in patients living at Manisa region (located at western Anatolia of Turkey). A total of 2279 cases [1465 male, 813 female; age range 1-87 (mean: 41.7) years] who were clinically prediagnosed as otomycosis at Celal Bayar University Hospital, between February 1995 and July 2011, were included in the study. External ear swab samples from patients with suspicion of otomycosis have been evaluated by routine mycological methods. Identification of mold-like fungi was based on colony morphology and microscopic examination of fungal structure, whereas germ tube test, growth characteristics on cornmeal-Tween 80 agar and API 20C AUX (bio-Mérieux, France) system were used for the identification of yeast-like fungi. Of the samples, 28% (638/2279) were found positive by direct microscopy and 24% (544/2279) by culture methods. Among culture-positive cases the isolation rates of mold-like and yeast-like fungi were 66% (359/544) and 34% (185/544), respectively. The number of distribution of the molds were as follows; Aspergillus niger (180), Aspergillus fumigatus (95), Aspergillus terreus (32), Aspergillus flavus (23), Aspergillus spp. (14), Penicillium spp. (13), Trichophyton spp. (T.rubrum 1, T.mentagrophytes 1); while this distribution was as follows for the yeasts; Candida tropicalis (97), Candida albicans (39), Candida parapsilosis (21), Candida glabrata (19), Candida kefyr (4), C.guilliermondii (2), Candida krusei (1), Geotrichum candidum (1) and Trichosporon capitatum (1). It was notable that 96% (344/359) of mold-like fungi were Aspergillus spp., and 99% (183/185) of yeast-like fungi were Candida spp. The results of this study indicated that the most frequent agents of otomycosis were non-dermatophyte species such as Aspergillus, followed by Candida. Dermatophytes were isolated in a small number of otomycosis cases. These data will provide support to the establishment of antifungal therapy guidelines for otomycosis.