Characteristics of Staphylococcus intermedius Isolates from Diseased and Healthy Dogs

Staphylococcus intermedius isolates from diseased and healthy dogs were examined for production of extracellular enzymes and toxins, and phage patterns. There were no significant differences between the two groups of isolates in the production rates of DNase, protease, lipase, gelatinase, hyaluronidase, hemolysins, protein A, and TSST-1, or in phage patterns. But the production rate of enterotoxins in isolates from diseased dogs was significantly higher than that in isolates from healthy dogs. PFGE analysis was performed with isolates from different body sites in individual dogs. In 3 of 6 healthy dogs, identical PFGE patterns were seen in isolates from the nares, external auditory meatus or skin. The remaining 3 dogs yielded isolates of different patterns. In 4 of 6 diseased dogs, identical patterns were seen in isolates from lesions as well as from the other normal sites.

Management of the draining ear in children

There are a variety of causes of otorrhea in children. The most important factor in reaching the proper diagnosis and providing relief of the problem is aural toilet. Once adequate debridement has been performed, the diagnosis is usually clearer, and treatment with ototopicals is significantly more effective. Most cases of otorrhea are due to infection or granulation tissue and can be managed initially with appropriately selected ototopical medication, thereby avoiding the risks and side effects of systemic therapy and the need for referral to a specialist. However, otorrhea in children that is refractory to medical therapy may be due to retained tympanostomy tubes or insidious pathology such as cholesteatoma or malignancy. In such cases, prompt referral to the otolaryngologist can facilitate accurate diagnosis and successful management.

Otitis externa infection in Jordan. Clinical and microbiological features

OBJECTIVE

Aims of this study were to investigate the clinical findings and to identify causative microorganisms and their susceptibility to antibiotics in otitis externa infection.

METHODS

The symptoms and signs, as well as the bacterial and fungal flora from the auditory canal of one hundred and eighty patients (100 males and 80 females), age range from 6 month to 19-years old suffering from acute otitis externa were studied from January 2001 to December 2002. One way ANOVA and Least Significant Difference (LSD) were carried out for statistical analysis.

RESULTS

Pain was the most common symptom (97.2%) while, itching and difficulty in hearing were the least common (11.7 %). Pseudomonas aeruginosa (P.aeruginosa) was isolated from (41.7%) which showed the best susceptibility to ciprofloxacin (93.4%), aspergillus species from (19.4%), candida albicans from (10.6%), staphylococcus aureus from (16.1%) which showed the best susceptibility to amikacin and ciprofloxacin (96.5%), proteus mirabilis from (2.8%) which showed the best susceptibility (100%) to amikacin, ciprofloxacin, imipenem and ofloxacin, anaerobic bacteria from (2.2%); and no bacteria growth was observed in (7.2%). There was a significant variation relating signs, symptoms and sex in favor of males (P=0.03). Significant seasonal variation in otitis externa infection was observed (P <0.05).

CONCLUSION

Pseudomonas aeruginosa was the most frequently isolated pathogenic microorganism, which showed the best susceptibility to ciprofloxacin. Pain was the most common symptom.

In vitro antimicrobial activity of orbifloxacin against Staphylococcus intermedius isolates from canine skin and ear infections

The objective of the study was to evaluate the in vitro activity of orbifloxacin against Staphylococcus intermedius strains isolated in France from canine skin and ear infections. The minimum inhibitory concentrations (MICs) of orbifloxacin against 240 field S. intermedius isolates (69 skin and 171 ear isolates) ranged from 0.016 to 8 mg l(-1), with MIC50 and MIC90 equal to 0.5 and 1 mg l(-1), respectively. Only one strain, a pyoderma isolate was resistant (MIC=8 mg l(-1)). Orbifloxacin was tested at different concentrations for killing rate against five isolates obtained from pyoderma cases and against a reference strain (Staphylococcus aureus ATCC 29213). Orbifloxacin expressed a concentration-dependent bactericidal activity against the S. aureus reference strain, but a time-dependent bactericidal activity against S. intermedius. Orbifloxacin induced bactericidal effect against the S. intermedius strains tested with concentrations equal to or two times MIC.

Declining susceptibility to neomycin and polymyxin B of pathogens recovered in otitis externa clinical trials

BACKGROUND

Otitis externa is usually treated empirically with topical neomycin/polymyxin B/hydrocortisone. The predominant pathogens associated with this infection are Pseudomonas aeruginosa and Staphylococcus aureus.

METHODS

Two multicenter clinical trials (one in adults and adolescents, and one in children), conducted between 1995 and 1996, compared neomycin/polymyxin B/hydrocortisone with ofloxacin for the treatment of otitis externa; two similar trials were conducted between 1999 and 2000. Assessments included the minimum inhibitory concentrations (MICs) of each antimicrobial drug for the major pathogens, bacterial eradication, and clinical efficacy.

RESULTS

The MICs of all bacterial isolates (including P. aeruginosa) for neomycin and polymyxin B increased markedly in the 1999 to 2000 studies compared with the 1995 to 1996 studies. In the later studies, mean MICs for all major pathogens tested had increased above the breakpoint for polymyxin B (> or = 4 microg/ml). In contrast, MICs of all isolates for ofloxacin remained similar between the two study periods and were within the susceptible range for this drug.

CONCLUSIONS

Although the bacterial eradication rates for both treatments in each study were equivalent, the clinical cure rate for neomycin/polymyxin B/hydrocortisone was lower (87%) than for ofloxacin (93%). Therefore, the organisms most often causing otitis externa appear to be developing resistance to neomycin and polymyxin B but not to ofloxacin.

Sensitivity and spectrum of bacterial isolates in infectious otitis externa

OBJECTIVE

To determine the spectrum and antibiotic sensitivity pattern of organisms from aural swabs taken from cases of infectious otitis externa.

DESIGN

Descriptive study.

PLACE AND DURATION OF STUDY

Department of ENT, Combined Military Hospital, Peshawar, from May 2002 to April 2003.

SUBJECTS AND METHODS

One hundred and twenty-four patients, diagnosed clinically as infectious otitis externa without concomitant suppurative otitis media, perforated tympanic membrane or otomycosis, were selected for the study. Samples of pus from external auditory canal were taken on sterile cotton swabs and were cultured on blood agar and MacConkey Agar for 24 to 48 hours. Sensitivity was tested and interpreted by Kirby-Bauer disc diffusion method of grading zones of inhibition.

RESULTS

One hundred and twenty four subjects were cultured. Sixteen samples showed no growth. One hundred and eight specimens yielded growth of bacteria. No specimen revealed multiple organisms. Staphylococcus aureus was found in 38%, and Pseudomonas aeruginosa was found in other 38%. Others included Proteus, Enterococci, Klebsiella, and E. coli. Majority of organisms were resistant to co-trimoxazole, amoxicillin and erythromycin, while 100% were sensitive to imipenem. Sensitivity to enoxacin was 96%, Ninety-two percent were sensitive to ciprofloxacin and ofloxacin.

CONCLUSION

Pseudomonas aeruginosa and Staphylococcus aureus were the most common bacterial isolates. Both were sensitive to fluoroquinolones. The latter can be used empirically for treatment of acute infectious otitis externa.

Efficacy of ofloxacin otic solution once daily for 7 days in the treatment of otitis externa: A multicenter, open-label, phase III trial

BACKGROUND

Otitis externa (OE) is an infection of the external auditory canal that is typically treated with topically applied broad-spectrum antibiotics. Twice-daily topical treatment with ofloxacin otic 0.3% solution for 10 days has been reported to be as effective and well tolerated as the standard of care, neomycin sulfate/polymyxin B sulfate/hydrocortisone solution administered 4 times daily for 10 days.

OBJECTIVE

This study evaluated the efficacy and safety profile of 7 days of a once-daily regimen of ofloxacin otic 0.3% solution in the treatment of OE.

METHODS

This multicenter, open-label, Phase III study was conducted from June 12, 2002, to October 14, 2002. Eligible patients were aged > or = 6 months and had OE of <2 weeks' duration with moderate to severe edema and tenderness involving 1 or both ears and sufficient exudate for microbiologic culture. Ofloxacin otic solution was instilled once daily for 7 days (5 drops for children aged 6 months to <13 years, 10 drops for adolescents/adults aged > or = 13 years). Assessments were conducted at the end-of-treatment visit and 7 to 10 days later (the test-of-cure visit). Medication was supplied free of charge to study participants who incurred no costs for physician visits.

RESULTS

Of 489 patients enrolled at 58 sites in 3 countries, 439 were clinically evaluable (173 children, 266 adolescents/adults; 52 % males, 48% females; 47% Hispanic, 45% white; 5% black, and 3% other). The cure rate among clinically evaluable patients was 91% (95% of children, 88% of adolescents/adults); 68% of patients were cured within 7 days. Forty-three potentially pathogenic strains were isolated from 253 microbiologically evaluable patients. Pseudomonas aeruginosa was isolated from 158 (62%) microbiologically evaluable patients and Staphylococcus aureus from 32 (13%). Eradication rates were 96% overall. No serious adverse events were observed. Minor adverse events were experienced by 15 (3%) of 489 patients included in the safety population. The most common adverse events were pruritus (5 patients), increased earache (4 patients), and application-site reactions (3 patients). Overall mean (SD) adherence to therapy was 98% (11.9).

CONCLUSIONS

Ofloxacin otic 0.3% solution administered once daily for 7 days was well tolerated and effective in achieving clinical and microbiologic cure of OE. The compliance rates in this study suggests that this regimen may be better accepted by patients than longer, more repetitive regimens.

Occurrence of Malassezia species in healthy and dermatologically diseased dogs

The presence of Malassezia spp. yeasts was investigated in dermatological specimens of 224 dogs, 164 dermatologically diseased and 60 normal dogs. Subjects included in the study were of different breed, age, sex and habitat. Malassezia spp. positive cultures were obtained in 142 (63.4%) specimens: 67.6% from dermatologically diseased subjects and 51.6% from healthy dogs. Malassezia pachydermatis, either as a pure culture or in association with lipid-dependent species, was identified in 138 (97%) specimens. Malassezia furfur was identified in 69 (48.6%) specimens and was associated with other Malassezia species in 68 dogs, as a pure culture in one subject: at the best of our knowledge, this species was identified before as the sole species from canine dermatitis. Malassezia sympodialis was identified in 11 (7.7%) specimens, always in association with other species: it was never isolated from kennel dogs. Statistical analysis of data showed a very significant difference (P < 0.01) in the prevalence of isolation of Malassezia spp. between animals with and without dermatological signs, and in the distribution of cultural burden between diseased and healthy dogs. A statistically significant difference (P<0.05) was also detected in the group of animals between 1- and 5-years of age. No significant difference was found between male and female dogs.

Pseudomonas aeruginosa from canine otitis externa exhibit a quorum sensing deficiency

Pseudomonas aeruginosa LasB elastase gene (lasB) transcription depends on cell density-dependent quorum-sensing mechanisms of gene activation. Previously, we collected several non-mucoid P. aeruginosa veterinary isolates and showed that the total matrix protease phenotype was similar for isolates regardless of host and site of isolation. In contrast, isolates from chronic canine ear infections (otitis externa) were significantly more likely to exhibit less elastase activity as measured by elastin Congo red than from any other site [Clin. Diag. Lab. Immun. 8 (2001) 632]. In this study, we found that the elastase deficiency phenotype is stable upon passage in broth culture. Transcript amplification analyses indicated that the elastase deficiency appears to be strain-specific, with each isolate exhibiting a unique expression profile relative to strain PAO1. Although a number of strain-specific transcriptional differences were observed, the overall pattern that emerges is a quorum sensing deficiency among canine ear P. aeruginosa isolates.

First Isolation of Cryptococcus magnus from a Cat

A 6-month-old male Japanese domestic cat with otitis externa due to Aspergillus fumigatus was treated with antifungal agents for 25 days and appeared to be cured. Many yeast colonies however developed from the ear canal samples on Sabouraud's dextrose agar at 27 degrees C for 5 days, instead of A. fumigatus. This yeast colony was cream-colored and slim in texture with smooth and highly glossy surface after 5-day incubation on Sabouraud's dextrose agar at 27 degrees C. The isolate was identified as Cryptococcus magnus by mycological analysis and 28S ribosomal analysis.

Otitis in cattle, an aetiological review

Otitis externa in cattle has a significant impact in tropical and subtropical regions, and the aetiological agents are predominantly rhabditiform nematodes and mites of the genus Raillietia. Its prevalence is higher in mature and Zebu cattle. In advanced clinical cases there can be irreversible and fatal neural lesions. Ear infection in calves has been associated with concurrent respiratory diseases and mixed infection. The principal reported agents of otitis in calves are bacteria such as Actinomyces spp., Corynebacterium pseudotuberculosis, Escherichia coli, Haemophilus somnus, Pasteurella multocida, Mannheimia haemolytica, Pseudomonas spp., Streptococcus spp. and Mycoplasma bovis. The control and treatment of bovine otitis is not standardized and there is little evidence-based support for the diverse treatments available in the literature.

Comparison of Microbial Isolates and Susceptibility Patterns From the External Ear Canal of Dogs With Otitis Externa

Otic exudate was obtained from 33 dogs with otitis externa for cytopathology and culture. Two samples were taken from the same location in the external ear canal, for a total of 100 samples. Thirty-six (36%) samples isolated only a single organism, of which 21 (21%) were Malassezia spp. Two organisms were present in 23 (23%) of the samples. Cultures of the two samples agreed in 40 (80%) of the 50 pairs. Cytopathology agreed with culture results only 68% of the time. Cytopathology and culture may not be as definitive as previously assumed because of apparent variability of the microbial population within the external canal.

The changing face of malignant (necrotising) external otitis: clinical, radiological, and anatomic correlations

Malignant (necrotising) external otitis is an invasive infection of the external auditory canal. Although elderly patients with diabetes remain the population most commonly affected, immunosuppressed individuals (eg, from HIV infection, chemotherapy, etc) are also susceptible to malignant external otitis. Pseudomonas aeruginosa is isolated from the aural drainage in more than 90% of cases. The pathophysiology is incompletely understood although aural water exposure (eg, irrigation for cerumen impaction) has been reported as a potential iatrogenic factor. The typical patient presents with exquisitely painful otorrhoea. If untreated, cranial neuropathies (most commonly of the facial nerve) can develop due to subtemporal extension of the infection. The diagnosis of malignant external otitis is based on a combination of clinical findings, an increased erythrocyte sedimentation rate, and radiographic evidence of soft tissue with or without bone erosion in the external canal and infratemporal fossa. Treatment consists of prolonged administration (6-8 weeks) of an antipseudomonal agent (typically an orally administered quinolone). With the introduction and widespread use of both oral and topical quinolones, there are reports of less severe presentation of malignant external otitis and even the emergence of ciprofloxacin resistance. Reservation of systemic quinolones for the treatment of invasive ear infections is recommended.

Chronic bilateral otomycosis caused by Aspergillus niger. Fallbericht. Chronisch bilaterale Otomykose durch Aspergillus niger

Aspergillus niger, an opportunistic filamentous fungus, was identified as the cause of chronic bilateral otomycosis in a 46-year-old female patient who was unresponsive to different drugs. The patient showed signs of erythema, otalgia, itching, otorrhoea and presence of greyish black coloured mass in both the ear canals. The direct microscopical examination of the ear debris in potassium hydroxide preparations, Giemsa, phase contrast and Gram revealed many thin, branched septate hyphae, condia and conidiophores morphologically indistinguishable from Aspergillus spp. The histopathological section of the ear wax mass by haematoxylin and eosin and periodic acid-Schiff techniques also showed similar fungal elements. The patient responded to 1% solution of mercurochrome. The use of mercurochrome in developing countries like India may be recommended to treat the fungal otitis in patients. We also emphasize that 'Narayan' stain should be routinely employed by microbiology and public health laboratories to study the morphology of pathogenic fungi.

Trichophyton rubrum in the external auditory meatus. Fallbericht. Trichophyton rubrum im ausseren Gehorgang

We report the case of a 28-year-old immunocompetent male suffering from otitis externa. The right external auditory meatus was filled with cerumen and detritus, the tympanic membrane covered wallpaper-like with layers of fungi. Mycological analysis revealed Trichophyton rubrum. With further examination tinea pedis of plantar and interdigital type and concomitant onychomycosis of the toenails due to T. rubrum could be detected. The auditory meatus was cleaned and treated topically with clotrimazole. Two weeks later the auditory meatus and the tympanic membrane were bare of fungi and the inflammation was resolved. Treatment of tinea pedis and onychomycosis with terbinafine (systemically and topically) is still lasting.

Poor-quality water in swimming pools associated with a substantial risk of otitis externa due to Pseudomonas aeruginosa

There are many large and small public outdoor and indoor swimming pools in Tehran that hundreds of people use, especially on hot summer days. The bacteriological quality of the water of some of these pools was assayed over a period of about one year (2001-2002). To assess if these swimming pools were a health risk to users, eleven public swimming pools, in the east and northeast of the city, were examined, and the exposed people were monitored. Samples of swimming-pool waters were examined for colony counts, Escherichia coli and coliforms. In addition, Pseudomonas aeruginosa was isolated from nine (81.8%) of those pools. P. aeruginosa grew in seven (63.6%) of the swimming-pool water samples. In two (18.2%) other samples, in addition to P. aeruginosa, high rates of total bacterial count, total coliforms and faecal coliform counts were also found. At the same time, users of the swimming pools were asked to complete a questionnaire. Ear swabs were collected from 179 users with a history of ear problems during the previous two weeks. An adequate control group was chosen randomly from those who never used the investigated pools. P. aeruginosa was isolated from the ear swabs of 142 (79.3%) of the cases, as well as from 4% of the controls. Results were matched for age, sex, duration of time spent in the pools, place of occurrence and other useful information. Investigation of the contaminated swimming pools revealed that chlorination was often inadequate, especially when high numbers of people led to overuse of the pools. Although the results of this research showed that otitis externa was strongly associated with the swimming pools, due to P. aeruginosa, an extensive follow-up study is needed to determine the other possible health risks associated with public pools.

[Effective antibacterial therapy in otorhinolaryngology: bacteriological rationale]

The article presents current views on etiopathogenesis of the diseases associated with contamination with microorganisms; reviews inflammatory ENT diseases in terms of current literature on clinical microbiology of these diseases; characterizes microorganisms more or less specific for each relevant nosological entity; analyses basic groups of antibacterial drugs with formulation of bacteriologically grounded principles of initial antibacterial therapy of ENT inflammation.

Temporomandibular joint involvement in malignant external otitis

OBJECTIVE

The purpose of this study was to present 6 patients with malignant external otitis (MEO) that resulted in temporomandibular joint (TMJ) involvement and to discuss the incidence, clinical presentation, and treatment modalities.

STUDY DESIGN

All patients diagnosed with MEO between 1994 and 2002 were reviewed for cases in which the TMJ was invaded by the infectious process. Only patients in whom TMJ involvement was documented radiographically and in whom the clinical course was well documented were included in this study.

RESULTS

MEO was diagnosed in 42 patients over an 8-year period; TMJ involvement was recorded in 6 patients (14%). The medical history revealed controlled type 2 diabetes mellitus in 4 of the 6 patients. All patients reported early ear symptoms, mainly otalgia and otorrhea. Local signs included an ear canal filled with granulation material, edematous overlying skin, and sensitivity to palpation. Cultures taken from the external ear were positive for either Pseudomonas aeruginosa, Staphylococcus epidermidis, Aspergillus, or Proteus mirabilis. TMJ symptoms developed between 1 and 5 months after admission and included painful periauricular swelling and trismus. In 3 patients, healing was uneventful; 3 also died of the disease.

CONCLUSIONS

TMJ involvement in MEO is associated with a resistant disease process, often with several recurrences. Prolonged administration of antibiotics is the treatment of choice. Surgical debridement of the TMJ is necessary for the positive identification of the pathogenic organism, in cases of abscess formation, or when osteomyelitic bone destruction of the condyle and glenoid fossa develop.