Malignant otitis externa: An updated review

Role of surgery along with antimicrobials in refractory skull base osteomyelitis-A prospective observational study

INTRODUCTION

Study aimed to ole of surgery along with antimicrobials to improve clinical outcomes in treating refractory cases of skull base osteomyelitis (SBO).

METHODS

A prospective observational study in a tertiary care centre with 70 SBO patients meeting eligibility criteria. The study population comprised 35 patients refractory to systemic antimicrobials of at least 4 weeks duration who later underwent surgery in addition to medication (surgical group). They were compared with a medical group that responded to medications alone. The outcome variables studied were the resolution of clinical features (pain, discharge, radiology, and inflammatory markers), culture yield, and total duration of treatment.

RESULTS

According to our study, relief of pain was faster in the surgical group (1.66 against 4.57 months) with statistical significance (p < 0.001). Relief of symptoms (p < 0.001), radiological improvement (p = 0.001), and normalising of inflammatory markers (p < 0.001) were better in the surgical group than in the medical group. The duration of treatment was an average of 9.2 months in the surgical group compared to 11.3 months in the medical group (p = 0.019). Microbial culture from deep tissue sampling was positive in 24 surgical patients (68.57%).

CONCLUSIONS

The treatment response in selected patients of refractory SBO who underwent surgery along with antimicrobials was better than the group who responded to antimicrobials alone. Surgery provided higher microbial yield resulting in culture-specific antimicrobials. The surgical group observed faster relief of symptoms, reduced hospital stay, and total treatment duration.

Serum Galactomannan as a Minimally Invasive Diagnostic Tool for Fungal Skull Base Osteomyelitis

Multidrug resistant strains and fungi add to treatment conundrums in skull base osteomyelitis (SBO). Deep tissue culture in these patients is challenging due to their advanced age and co-morbidities. Besides, fungal culture positivity is seen only in 60% of invasive aspergillosis. To determine the efficacy of a minimally invasive test-Serum Galactomannan (sGM)-for diagnosing fungal SBO. Prospective observational study. Thirty- three patients, clinically diagnosed with SBO were included in this study. Baseline ESR (Erythrocyte Sedimentation Rate), CRP (C- Reactive Protein), pain score, and sGM were noted for all patients. Antifungal Voriconazole was initiated on patients if the sGM values were more than 0.8. At the 12th week of treatment, all parameters were repeated and compared with the baseline values. A significant reduction was noted in ESR, CRP, and pain scores at the 12th week of treatment compared to the baseline values in patients with raised sGM values who were started on Voriconazole. For a culture-proven fungal skull base osteomyelitis with a cut-off value of sGM > / = 0.8, the obtained sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 81.82, 36.36, 39.13, 80 and 51.52% respectively. At a cut-off value of sGM > / = 01.6, the values of sensitivity/specificity, PPV, NPV and accuracy were 81.82/72.73%, 60%, 88.89% and 75.76%. Culture-negative patients in SBO with sGM value > 0.8 were more likely to be fungal SBO. An sGM cut-off of 1.6 was observed to give maximum accuracy for diagnosing fungal SBO.

Hyperbaric oxygen therapy in malignant otitis externa: a retrospective analysis

PURPOSE

Malignant otitis externa (MOE) is a rare form of invasive osteomyelitis of the external ear canal. It is typically caused by Pseudomonas aeruginosa in immunocompromised patients. The diagnosis is clinical, and the initial treatment involves systemic antibiotics or antifungal therapy. Surgery is usually only considered when medical treatment has failed. Although hyperbaric oxygen therapy (HBOT) is recommended for refractory osteomyelitis, there are no specific guidelines for MOE.

METHODS

This is a retrospective study that evaluates clinical data, treatment, and results obtained in patients diagnosed with MOE treated with HBOT at the Pedro Hispano Hospital between 2007 and 2022.

RESULTS

During the study period, fifteen patients diagnosed with MOE were admitted for treatment with HBOT. All patients received antibiotic and/or antifungal therapy, and three required surgical intervention before starting HBOT. The pathology was successfully managed on all patients.

CONCLUSIONS

HBOT may be an effective adjuvant treatment option in patients with MOE but it lacks robust scientific evidence. However, its therapeutic value should not be underestimated due to the good results and few adverse effects reported in recent retrospective studies and case reports.

Role of follow-up gallium scintigraphy in the evaluation of malignant external otitis (skull base osteomyelitis): A case report

Malignant otitis externa (skull base osteomyelitis) can be fatal and long-term antibiotic therapy is recommended. Despite being potentially fatal, this infection causes minor changes in inflammatory biomarkers (white blood cell count and C-reactive protein levels) upon blood testing. Computed tomography and magnetic resonance imaging changes persist over a long period. Therefore, it is difficult to determine the optimal time for the discontinuation of antibiotics. We present a 77-year-old male whose medical history included type 2 diabetes mellitus who suffered from chronic otitis media with Pseudomonas aeruginosa infection. His condition did not improve with proper treatment, and imaging revealed malignant otitis media. Intravenous cefepime treatment was administered. Antibiotic treatment was de-escalated to oral levofloxacin treatment after Gallium-67 scintigraphy showed less accumulation after 6 weeks of Cefepime administration; accumulation almost disappeared after 1 year. In this report, we describe the usefulness of gallium scintigraphy in the evaluation of malignant otitis externa.

Diagnostic criteria and core outcome set development for necrotising otitis externa: the COSNOE Delphi consensus study

OBJECTIVE

Evidence for necrotising otitis externa (NOE) diagnosis and management is limited, and outcome reporting is heterogeneous. International best practice guidelines were used to develop consensus diagnostic criteria and a core outcome set (COS).

METHODS

The study was pre-registered on the Core Outcome Measures in Effectiveness Trials (COMET) database. Systematic literature review identified candidate items. Patient-centred items were identified via a qualitative study. Items and their definitions were refined by multidisciplinary stakeholders in a two-round Delphi exercise and subsequent consensus meeting.

RESULTS

The final COS incorporates 36 items within 12 themes: Signs and symptoms; Pain; Advanced Disease Indicators; Complications; Survival; Antibiotic regimes and side effects; Patient comorbidities; Non-antibiotic treatments; Patient compliance; Duration and cessation of treatment; Relapse and readmission; Multidisciplinary team management.Consensus diagnostic criteria include 12 items within 6 themes: Signs and symptoms (oedema, otorrhoea, granulation); Pain (otalgia, nocturnal otalgia); Investigations (microbiology [does not have to be positive], histology [malignancy excluded], positive CT and MRI); Persistent symptoms despite local and/or systemic treatment for at least two weeks; At least one risk factor for impaired immune response; Indicators of advanced disease (not obligatory but mut be reported when present at diagnosis). Stakeholders were unanimous that there is no role for secondary, graded, or optional diagnostic items. The consensus meeting identified themes for future research.

CONCLUSION

The adoption of consensus-defined diagnostic criteria and COS facilitates standardised research reporting and robust data synthesis. Inclusion of patient and professional perspectives ensures best practice stakeholder engagement.

Chronic otorrhea and osteomyelitis of the external auditory canal by Achromobacter xylosoxidans: an uncommon diagnosis

PURPOSE

Achromobacter xylosoxidans is an emerging pathogen mainly associated with resistant nosocomial infections. This bacteria had been isolated in the ear together with other pathogens in cultures from patients with chronic otitis media, but it had never been reported as a cause of osteomyelitis of the external auditory canal.

CASE PRESENTATION

We present a unique case of a healthy 81-year-old woman who presented with left chronic otorrhea refractory to topical and oral antibiotic treatment. Otomicroscopy revealed an erythematous and exudative external auditory canal (EAC) with scant otorrhea. The tympanic membrane was intact, but an area of bone remodeling with a small cavity anterior and inferior to the bony tympanic frame was observed. Otic culture isolated multi-drug-resistant A. xylosoxidans, only sensitive to meropenem and cotrimoxazole. Temporal bone computed tomography showed an excavation of the floor of the EAC compatible with osteomyelitis. Targeted antibiotherapy for 12 weeks was conducted, with subsequent resolution of symptoms and no progression of the bone erosion.

CONCLUSIONS

Atypical pathogens such as A. xylosoxidans can be the cause of chronic otitis externa. Early diagnosis and specific antibiotherapy can prevent the development of further complications, such as osteomyelitis. In these cases, otic cultures play an essential role to identify the causal germ. This is the first case of EAC osteomyelitis due to A. xylosoxidans reported to date.

Management and Outcomes of Necrotizing Otitis Externa: A Retrospective Cohort Study in a Tertiary Referral Center

Objectives

Necrotizing otitis externa (NOE) is a rare infection of the ear that causes osteomyelitis. We aimed to evaluate treatment outcomes and the role of imaging in diagnosing and monitoring disease resolution in a single-center study of patients with NOE.

Methods

In this retrospective cohort study, patients with NOE who were diagnosed and treated in a tertiary otology center in Utrecht, The Netherlands, between January 1, 2013 and August 1, 2022, were included. Data were retrieved from the medical records on demographics, symptoms, physical and diagnostic findings, type and duration of treatment, and course of disease.

Results

A total of 24 cases were included. Patients were often elderly (mean age = 75 years) and diabetic (88%). Pseudomonas aeruginosa was the most commonly found microorganism (63%). Twenty-two cases (92%) received intravenous antibiotic treatment, and 7 cases (29%) received additional systemic antifungal treatment. The mean duration of systemic treatment was 29 weeks. In 20 out of 22 cases (91%), imaging was used to determine the end point of treatment. None of the cases with a total resolution of disease activity (n = 5) on 18F-fluorodeoxyglucose-positron emission tomography-computed tomography imaging at the time of cessation of therapy showed clinical relapse, compared with 1 out of 4 cases on gallium single-photon emission computerized tomography.

Conclusion

Based on the experience from our center, we demonstrated that patients with NOE can successfully be treated with prolonged systemic treatment. Molecular imaging is reasonably successful for disease evaluation and decision-making on the eradication of disease.

The Association Between Malignant Otitis Externa and Diabetes Mellitus in Africa: A Systematic Review

Diabetes mellitus is one of the risk factors for malignant otitis externa. There are very few studies on the disease in Africa and there is a need to pool the prior studies to highlight the characteristics of the disease. The study type is a systematic review and the PRISMA guidelines were followed. Using the appropriate terms, relevant medical databases were systematically searched. Thirty-two studies met the eligibility criteria with a total sample size of 848, who were mainly elderly. Diabetes mellitus was present in 94% of the participants. Average duration of diabetes diagnosis in the participants was 12.4 years. The pooled HbA1c was 9.8%. The most common symptoms were otalgia (96.1%), otorrhoea (75.8%) and hearing loss (56.1%). Pseudomonas was the most common isolate (72%). Fluoroquinolones and the 3rd-generation cephalosporins were the preferred antibiotics. The pooled cure rate from antimicrobial usage was 76.2%. In addition to medications, 24.6% of the affected individuals required debridement. About 1.6% of the participants died from malignant otitis externa. Malignant otitis externa is associated with poorly controlled diabetes. Pseudomonas is the most common cause and a significant proportion gets cured with prolonged antibiotherapy.

Central Skull Base Osteomyelitis: A Case Series from a Tertiary Care Center Over 5 Years

OBJECTIVE

Skull base osteomyelitis may rarely present in the sphenoid bone or clivus without an otologic source. This is referred to as central skull base osteomyelitis (CSBO). Knowledge regarding CSBO is limited to case reports and small case series. Here we present a case series to further describe typical patient characteristics, clinical presentation, and clinical course associated with this rare infection.

METHODS

All patients treated at a single academic tertiary care institution for CSBO from 2016 through 2020 were identified. Inclusion criteria included culture proven CSBO without an otologic or iatrogenic source. Data were extracted via patient chart review and qualitatively analyzed.

RESULTS

Seven patients were identified with CSBO, 5 male and 2 female. Age ranged from 63 to 87 (average 76). Risk factors included advanced age, diabetes, and history of radiation. The most common presenting symptom was headache (6), followed by otalgia (4). Two patients presented with cranial neuropathies. Diagnosis was facilitated by history and exam (including flexible laryngoscope exam), imaging (MRI), and labs (ESR). All patients received endoscopic biopsy and culture (most commonly polymicrobial, with diverse species). Treatment involved IV antibiotics, with a limited role for surgery. All patients survived and achieved resolution of infection.

CONCLUSIONS

CSBO remains a diagnostic challenge due to its rarity and vague presenting symptoms that overlap with presentation of sinonasal malignancies. A high index of suspicion is required by the evaluating provider to ensure a timely diagnosis with early treatment in order to limit the significant morbidity which can be associated with this infection.

LEVEL OF EVIDENCE

4.

Skull Base Osteomyelitis: Historical Perspective, Diagnosis and Management Update

SBO is a life-threatening disease that requires a high index of suspicion based on these patients complex underlying medical co-morbidities and clinician's acumen. Once a diagnosis is made, is it critical to communicate and work closely with other multidisciplinary teams (neuroradiology for appropriate choice of imaging study and interpretation; infectious disease for appropriate medical treatment and duration; internist to properly manage their underlying medical co-morbidities). Despite advances in imaging, the diagnosis is first made based on clinical judgment, appropriate culture, and tissue biopsy.

Are artificial intelligence large language models a reliable tool for difficult differential diagnosis? An a posteriori analysis of a peculiar case of necrotizing otitis externa

Key Clinical Message

Large language models have made artificial intelligence readily available to the general public and potentially have a role in healthcare; however, their use in difficult differential diagnosis is still limited, as demonstrated by a case of necrotizing otitis externa.

Abstract

This case report presents a peculiar case of necrotizing otitis externa (NOE) with skull base involvement which proved diagnostically challenging. The initial patient presentation and the imaging performed on the 78-year-old patient suggested a neoplastic rhinopharyngeal lesion and only after several unsuccessful biopsies the patient was transferred to our unit. Upon re-evaluation of the clinical picture, a clinical hypothesis of NOE with skull base erosion was made and confirmed by identifying Pseudomonas aeruginosa in biopsy specimens of skull base bone and external auditory canal skin. Upon diagnosis confirmation, the patient was treated with culture-oriented long-term antibiotics with complete resolution of the disease. Given the complex clinical presentation, we chose to submit a posteriori this NOE case to two large language models (LLM) to test their ability to handle difficult differential diagnoses. LLMs are easily approachable artificial intelligence tools that enable human-like interaction with the user relying upon large information databases for analyzing queries. The LLMs of choice were ChatGPT-3 and ChatGPT-4 and they were requested to analyze the case being provided with only objective clinical and imaging data.

Perspectives of Italian Physicians and Patients in the Treatment of Otitis Externa: A Real-Life Study

(1) Background: Otitis externa (OE) is a common inflammatory disease of the external ear canal. Given the numerous manifestations of OE, the high rate of recurrence of the disease, as well as the emergence of resistance to antibiotics, therapeutic strategies are numerous and still not well standardized. The aim of this study was to investigate the patient journey of Italian patients suffering from OE, paying greater attention to new therapeutic options. (2) Methods: We conducted a national survey to evaluate the characteristics of patients affected by OE and to analyze the most-prescribed treatments. (3) Results: OE is a common, often relapsing disease that has several clinical manifestations. Prior to observation, the combination of corticosteroids and topical antibiotics was the most common therapeutic strategy. At the time of observation, new liposomal ozone-based preparations were the most-prescribed treatment. (4) Conclusions: This multi-center study investigated key aspects of the OE patient journey, highlighting the growing problem of antibiotic resistance. Restoring a correct ear microbiome is the therapeutic goal. In this context, new liposomal ozone-based drugs represent a promising therapeutic strategy.

Suppurative Meningoencephalitis by Pseudomonas aeruginosa from Direct Extension of Chronic Otitis in a Gir Cow

This paper aims to report clinical, laboratory and pathological features in a case of suppurative meningoencephalitis by P. aeruginosa from the direct extension of chronic otitis in a Gir cow. The cow was recumbent during physical examination, and neurological examination revealed depression, absence of left eyelid and auricular motor reflex, and hypotonic tongue. Hematology revealed hemoconcentration, leukocytosis by neutrophilia, and hyperfibrinogenemia. Cerebrospinal fluid was slightly turbid, and presented polymorphonuclear pleocytosis, and hyperproteinorrachia. Grossly, the skull floor showed a purulent green-yellow exudate that drained from the left inner ear to the cisterna magna. There was diffuse congestion of the telencephalon, and meninges showed severe hyperemia, moderate thickening, and opacity with the deposition of fibrinosuppurative material ventrally, extending to the cerebellum and brainstem. The left cerebellar hemisphere showed an approximately 1.5 cm in diameter liquefaction area surrounded by a hemorrhagic halo. Histologically, cerebellar, mesencephalic, thalamic, and brain base meninges were intensely thickened and showed severe suppurative inflammation and fibrin deposition. Small multifocal suppurative areas were observed in the cerebellum and brainstem, characterized by a necrotic core, a number of neutrophils, and Gram-negative intralesional bacillary myriads. Pure cultures of P. aeruginosa were obtained and identified in the suppurative CNS lesions, meninges, and inner ear samples. This report highlights an uncommon clinical evolution of secondary P. aeruginosa suppurative meningoencephalitis, probably triggered by recurrent parasitic otitis in an adult Gir cow. Veterinarians, practitioners, and farmers must be aware of the risk of CNS infections after unresolved media and inner otitis, especially in cattle breeds more prone to developing parasitic otitis, such as the Gir and Indubrasil breeds.

Clinical Spectrum and Treatment Response of Malignant Otitis Externa Patients: A Rural Tertiary Care Centre Experience

INTRODUCTION

Malignant otitis externa (MOE) is an invasive external ear infection that has a tendency to spread through the temporal bone and can further progress to involve intracranial structures. Though the prevalence of MOE is rare, high morbidity and mortality are often associated. Complications of advanced MOE include cranial nerve involvement, most commonly facial nerve, and intracranial infections such as abscesses and meningitis.

MATERIALS AND METHODS

In this retrospective case series of nine patients diagnosed with MOE, demographic data, clinical presentations, laboratory data, and radiological findings were reviewed. All patients were followed up for a minimum period of three months after discharge. Outcomes were measured in terms of reduction in obnoxious ear pain (Visual Analogue Scale), ear discharge, tinnitus, need for re-hospitalization, recurrence of disease, and overall survival.

RESULTS

In our case series of nine patients (seven males and two females), six underwent surgery, and three patients were managed with a medical line of treatment. All patients had a significant reduction in otorrhea, otalgia, random venous blood sugars, and improvement of facial palsy implicating good response to treatment.

CONCLUSION

Prompt diagnosis of MOE warrants clinical expertise and aids in preventing complications. A prolonged course of intravenous anti-microbial agents is the mainstay of treatment, but timely surgical interventions in treatment-resistant cases can prevent complications.

Malignant External Otitis: What the Diabetes Specialist Should Know-A Narrative Review

AIMS

Malignant external otitis (MEO) is a special type of external otitis associated with extensive inflammation and osteomyelitis. It is believed to originate from the external auditory meatus and advance regionally to the soft tissues and the bone, eventually involving the skull base. Pseudomonas aeruginosa and diabetes mellitus are factors commonly involved in the pathogenesis of MEO. Although its treatment has changed considerably during the last decades, morbidity and mortality of the disease remain high. Our aim was to review basic aspects of MEO, a disease unknown until 1968, which attracts great interest among Ears, Nose and Throat (ENT), diabetes and infectious diseases specialists.

METHODS AND RESULTS

In this narrative review we mainly include relevant papers written in English or with an English abstract. We searched PubMed and Google Scholar, using the keywords malignant external otitis, malignant otitis externa, necrotizing external otitis, skull base osteomyelitis, diabetes mellitus and surgery up to July 2022. Some of the most recent articles, with specific references to earlier articles and a book reference regarding the pathophysiology, diagnosis and treatment of MEO and its relationship to diabetes mellitus, were included.

CONCLUSION

MEO is not an uncommon disease and is principally treated by ENT surgeons. Nevertheless, diabetes specialists should be aware of the disease presentation and management, since they will often encounter patients with undiagnosed MEO or will need to manage glucose levels in patients hospitalized with the disease.

Trends and Outcomes of Fungal Temporal Bone Osteomyelitis: A Scoping Review

INTRODUCTION

Temporal bone osteomyelitis is an invasive infection most often caused by bacteria and associated with high mortality. Fungal etiologies are rare and little is known of the predictors of disease severity and outcomes in fungal temporal bone osteomyelitis.

MATERIALS AND METHODS

A scoping review was performed to determine what is known from the literature on how clinical, diagnostic, and treatment characteristics relate to patient outcomes in fungal temporal bone osteomyelitis. Using PRISMA guidelines, three databases were searched to identify all published cases of fungal temporal bone osteomyelitis. Data were extracted from each study, including clinical, diagnostic, and treatment characteristics, and outcomes.

RESULTS

Sixty-eight studies comprising 74 individual cases of fungal temporal bone osteomyelitis were included. All studies were case reports. There were high rates of diabetes, facial nerve palsy, infectious complications, and need for surgical intervention, as well as a significant delay in the evaluation and diagnosis of fungal temporal bone osteomyelitis. Disease recovery was greater in patients presenting with otorrhea, comorbid diabetes, and in those without facial nerve palsy.

DISCUSSION

Many of the defining characteristics of fungal temporal bone osteomyelitis remain unknown, and future reports should focus on determining factors that improve timely diagnosis and treatment of fungal TBO in addition to identifying prognostic indicators for outcomes and survival.

Improving patient care pathways in otitis externa

INTRODUCTION

Referrals for otitis externa (OE) have dramatically increased but the reasons for this remain unclear. We aim to characterize management of patients both pre- and post-referral to identify areas of improvement at the primary-secondary care interface.

METHODS

Questionnaire study from consultant-led research clinic specifically set up to prospectively analyse OE referrals at a tertiary referral centre for Otolaryngology.

RESULTS

Sixty-two patients were included; 63% female, median age 57 years. One was excluded (clinically not OE). Most patients had multiple primary care visits before referral (average 4 GP; 2 practice nurse). Sixty per cent had received oral antibiotics (16% multiple classes). Eighteen per cent had never had ear drops. Thirty-nine per cent were not advised to keep ears dry. Twenty-one per cent had dermatitis; 13% contact allergy, 30% systemic allergy, 5% diabetes. Less than 10% had narrow canals. Thirty-six per cent had active discharge but <7% needed a wick. Approximately 75% appear suitable for community aural care clinics.

CONCLUSIONS

OE occurs most commonly in female patients, often with associated risk factors. Patients often consult primary care several times prior to referral. Lifestyle advice and ototopical drops are frequently overlooked; instead, often inappropriately treated with oral antibiotics. Most ears were anatomically normal, and community aural care clinics may have a role in more timely and accessible treatment.

Retrospective analysis of outcomes of outpatient parenteral antimicrobial therapy (OPAT) for necrotising otitis externa

Necrotising otitis externa (NOE) is an uncommon but life-threatening infection that requires prolonged systemic antimicrobial therapy. This study aims to identify factors associated with treatment response and outcome in patients with NOE treated through outpatient parenteral antimicrobial therapy (OPAT). We performed a retrospective analysis of patients with NOE treated over a 4-year period (January 2018-January 2022) at a tertiary referral hospital in Derbyshire, UK. We defined OPAT failure as unplanned readmission within 30 days of discontinuation of OPAT. Prolonged duration of therapy was defined as length of parenteral antimicrobial treatment of more than 8 weeks. A total of 46 cases of NOE were reviewed. OPAT failure and prolonged therapy were recorded in 9 (19.6%) and 23 (50.0%) episodes respectively. Facial nerve involvement (odds ratio [OR], 14.54; 95% confidence interval [CI], 2.76-76.60; p = 0.002), dementia (OR, 7.65; 95% CI, 1.23-47.46; p = 0.029), Charlson comorbidity score (OR, 1.41 per unit increase; 95% CI, 1.00-2.00; p = 0.049) and peak CRP level (OR, 1.03 per unit increase; 95% CI, 1.00-1.06; p = 0.027) were associated with increased risk of treatment failure. Facial nerve involvement (OR, 16.30; 95% CI, 2.60-102.31; p = 0.003) and peak CRP level (OR, 1.04; 95% CI, 1.01-1.07; p = 0.016) were also associated with an increased need for prolonged antimicrobial therapy. In addition, extent of disease (based on imaging findings) was linked to prolonged therapy (OR, 22.89; 95% CI, 3.62-144.76; p = 0.001). NOE could be effectively managed as outpatient via OPAT. However, vigorous antimicrobial treatment and close monitoring of patients with pre-existing comorbidities, facial nerve paralysis, extensive disease and markedly elevated inflammatory markers are essential to optimise clinical outcomes.

Necrotising Otitis Externa Antibiotic therapy complications: A retrospective cohort analysis

NOE is a rare but life-threatening condition. Treatment is long-term intravenous antibiotics. However, there is no evidence on the complications of antibiotic treatment in this complex cohort of patients In our study, patients on average are treated with two different antibiotic regimes 63% of these changes in regimen are due to direct adverse effects from treatment including drug intolerance and lack of significant clinical response leading to deterioration and morbid complications Patients requiring multiple antibiotic regimes have a statistically longer duration of treatment. These adverse effects appear to occur more frequently in patients with additional comorbidities. This novel data provides information clinicians can use when initiating treatment for NOE and counsel patients appropriately.

Conventional Antifungals for Invasive Infections Delivered by Unconventional Methods; Aerosols, Irrigants, Directed Injections and Impregnated Cement

The administration of approved antifungals via unapproved formulations or administration routes (such as aerosol, direct injection, irrigation, topical formulation and antifungal-impregnated orthopedic beads or cement) may be resorted to in an attempt to optimize drug exposure while minimizing toxicities and/or drug interactions associated with conventional (systemic) administrations. Existing data regarding such administrations are mostly restricted to uncontrolled case reports of patients with diseases refractory to conventional therapies. Attribution of efficacy and tolerability is most often problematic. This review updates prior published summaries, reflecting the most recent data and its application by available prevention and treatment guidelines for invasive fungal infections. Of the various dosage forms and antifungals, perhaps none is more widely reported than the application of amphotericin B-containing aerosols for the prevention of invasive mold infections (notably Aspergillus spp.).

Necrotising otitis externa: a serious condition becoming more frequently encountered

BACKGROUND

Necrotising otitis externa is an aggressive infection of the external ear, which extends to the surrounding bone and soft tissue. In recent years, there has been an apparent increase in the number of patients admitted to our hospital with this condition.

METHODS

A retrospective review was conducted of all patients admitted to our hospital with necrotising otitis externa between July 2012 and June 2020.

RESULTS

Among 39 patients included, only 9 were diagnosed in the first four years, and 30 were diagnosed in the last four years. There were 27 males and 12 females, and the mean age was 78.7 years. There were six non-diabetic immunocompetent patients. Cranial nerve palsies developed in 50 per cent of the patients. Disease-related mortality was 7.7 per cent. A favourable outcome was recorded in 66.7 per cent of the patients.

CONCLUSION

Necrotising otitis externa is associated with high morbidity and mortality. The incidence of the disease is rising in our local geographical area.

Sanguinarine Inhibits the 2-Ketogluconate Pathway of Glucose Utilization in Pseudomonas aeruginosa

Interfering with the ability of pathogenic bacteria to import glucose may represent a new promising antibacterial strategy, especially for the treatment of infections occurring in diabetic and other hyperglycemic patients. Such patients are particularly susceptible to infections caused by a variety of bacteria, among which opportunistic pathogens like Pseudomonas aeruginosa. In P. aeruginosa, glucose can be directly imported into the cytoplasm or after its periplasmic oxidation into gluconate and 2-ketogluconate (2-KG). We recently demonstrated that a P. aeruginosa mutant lacking the 2-KG transporter KguT is less virulent than its kguT⁺ parental strain in an insect infection model, pointing to 2-KG branch of glucose utilization as a possible target for anti-Pseudomonas drugs. In this work, we devised an experimental protocol to find specific inhibitors of the 2-KG pathway of P. aeruginosa glucose utilization and applied it to the screening of the Prestwick Chemical Library. By exploiting mutants lacking genes involved in the transport of glucose derivatives in the primary screening and in the secondary assays, we could identify sanguinarine as an inhibitor of 2-KG utilization. We also demonstrated that sanguinarine does not prevent 2-KG formation by gluconate oxidation or its transport, suggesting that either KguD or KguK is the target of sanguinarine in P. Aeruginosa.

Pseudomonas aeruginosa: a clinical and genomics update

Antimicrobial resistance (AMR) has become a global medical priority that needs urgent resolution. Pseudomonas aeruginosa is a versatile, adaptable bacterial species with widespread environmental occurrence, strong medical relevance, a diverse set of virulence genes and a multitude of intrinsic and possibly acquired antibiotic resistance traits. P. aeruginosa causes a wide variety of infections and has an epidemic-clonal population structure. Several of its dominant global clones have collected a wide variety of resistance genes rendering them multi-drug resistant (MDR) and particularly threatening groups of vulnerable individuals including surgical patients, immunocompromised patients, Caucasians suffering from cystic fibrosis (CF) and more. AMR and MDR especially are particularly problematic in P. aeruginosa significantly complicating successful antibiotic treatment. In addition, antimicrobial susceptibility testing (AST) of P. aeruginosa can be cumbersome due to its slow growth or the massive production of exopolysaccharides and other extracellular compounds. For that reason, phenotypic AST is progressively challenged by genotypic methods using whole genome sequences (WGS) and large-scale phenotype databases as a framework of reference. We here summarize the state of affairs and the quality level of WGS-based AST for P. aeruginosa mostly from clinical origin.