Auricular Research Articles

BMP signaling maintains auricular chondrocyte identity and prevents microtia development by inhibiting protein kinase A.

Elastic cartilage constitutes a major component of the external ear, which functions to guide sound to the middle and inner ears. Defects in auricle development cause congenital microtia, which affects hearing and appearance in patients. Mutations in several genes have been implicated in microtia development, yet, the pathogenesis of this disorder remains incompletely understood. Here, we show that Prrx1 genetically marks auricular chondrocytes in adult mice. Interestingly, BMP-Smad1/5/9 signaling in chondrocytes is increasingly activated from the proximal to distal segments of the ear, which is associated with a decrease in chondrocyte regenerative activity. Ablation of Bmpr1a in auricular chondrocytes led to chondrocyte atrophy and microtia development at the distal part. Transcriptome analysis revealed that Bmpr1a deficiency caused a switch from the chondrogenic program to the osteogenic program, accompanied by enhanced protein kinase A activation, likely through increased expression of Adcy5/8. Inhibition of PKA blocked chondrocyte-to-osteoblast transformation and microtia development. Moreover, analysis of single-cell RNA-seq of human microtia samples uncovered enriched gene expression in the PKA pathway and chondrocyte-to-osteoblast transformation process. These findings suggest that auricle cartilage is actively maintained by BMP signaling, which maintains chondrocyte identity by suppressing osteogenic differentiation.

BMP signaling maintains auricular chondrocyte identity and prevents microtia development by inhibiting protein kinase A

Elastic cartilage constitutes a major component of the external ear, which functions to guide sound to the middle and inner ears. Defects in auricle development cause congenital microtia, which affects hearing and appearance in patients. Mutations in several genes have been implicated in microtia development, yet, the pathogenesis of this disorder remains incompletely understood. Here, we show that Prrx1 genetically marks auricular chondrocytes in adult mice. Interestingly, BMP-Smad1/5/9 signaling in chondrocytes is increasingly activated from the proximal to distal segments of the ear, which is associated with a decrease in chondrocyte regenerative activity. Ablation of Bmpr1a in auricular chondrocytes led to chondrocyte atrophy and microtia development at the distal part. Transcriptome analysis revealed that Bmpr1a deficiency caused a switch from the chondrogenic program to the osteogenic program, accompanied by enhanced protein kinase A activation, likely through increased expression of Adcy5/8. Inhibition of PKA blocked chondrocyte-to-osteoblast transformation and microtia development. Moreover, analysis of single-cell RNA-seq of human microtia samples uncovered enriched gene expression in the PKA pathway and chondrocyte-to-osteoblast transformation process. These findings suggest that auricle cartilage is actively maintained by BMP signaling, which maintains chondrocyte identity by suppressing osteogenic differentiation.

[Analysis of clinical manifestations and imaging features of facial nerve schwannomas].

Objective:To explore the clinical manifestations and imaging characteristics, and to clarify the imaging value in the diagnosis of facial nerve schwannomas. Methods:Retrospectively analyze the data of 23 patients with facial nerve schwannomas confirmed by surgery and pathology in the Department of Otorhinolaryngology of the First Affiliated Hospital of the Air Force Military Medical University from September 2020 to September 2022, including 8 males and 15 females, aged 18-66 years old. Summarize and analyze their clinical symptoms, specialized examinations, and imaging findings. Results:The clinical manifestations were facial nerve paralysis in 15 cases（2 cases of HB Ⅳ, 6 cases of HB Ⅴ, 7 cases of HB Ⅵ）, hearing loss in 14 cases（5 cases of conductive deafness, 2 cases of mixed deafness, and 7 cases of severe sensorineural hearing loss）, 8 cases tinnitus, 7 cases ear pain, 4 cases dizziness, 4 cases headache, 2 cases ear pus, and parotid gland tumors in 6 cases presenting as local masses. Endoscopic examination revealed 8 cases of external ear canal tumors and 3 cases of intratympanic tumors. Combining temporal bone HRCT, MRI enhanced scanning, and CPR imaging techniques, 1 case involved the internal auditory canal segment, 2 cases in the tympanic segment, 6 cases in the parotid gland area. A total of 14 cases involved two or more segments of the internal auditory canal segment, the labyrinthine segment, geniculate ganglion, the tympanic segment, and the mastoid segment. When the tumors were large, adjacent structures were involved. It was found that 8 cases invaded the external auditory canal and tympanic cavity, ossicles were displaced or bony destruction; 3 cases invaded the jugular foramen area, and 1 case grew to the middle cranial fossa region with temporal lobe brain parenchymal compression. Conclusion:The clinical manifestations of facial nerve schwannomas are diverse. The combination of various imaging techniques will be conducive to topical and qualitative diagnosis and provide an important basis for treatment strategies.

Mycobiome of the external ear canal of healthy cows.

Malassezia yeasts belong to the normal skin microbiota of a wide range of warm-blooded animals. However, their significance in cattle is still poorly understood. In the present study, the mycobiota of the external ear canal of 20 healthy dairy Holstein cows was assessed by cytology, culture, PCR, and next-generation sequencing. The presence of Malassezia was detected in 15 cows by cytology and PCR. The metagenomic analysis revealed that Ascomycota was the predominant phylum but M. pachydermatis the main species. The Malassezia phylotype 131 was detected in low abundance. Nor M. nana nor M. equina were detected in the samples.

Congenital aural atresia in a 4‐month‐old Dalmatian

AbstractA 4‐month‐old female entire Dalmatian was presented for persistently excessive ceruminous discharge, suspected left aural malformation and decreased hearing. Otoscopic examination of the left ear showed a normal external meatus with an abnormal ending of the ear canal in a cul‐de‐sac. Computed tomography (CT) study of the head showed a diffusely tortuous and convoluted external ear canal with saccular distension and a stenotic area with the presence of a septum. Based on the clinical presentation and imaging findings, total ear canal ablation and lateral bulla osteotomy were performed. Macroscopically, the ear canal appeared to be sigmoid, as in the CT study. Notably, in the stenotic area, there was a membrane separating the vertical and horizontal ear canals. The histopathology of the external ear canal was consistent with that of hyperplastic otitis externa. No growth was observed on bacterial culture. The dog recovered uneventfully and no abnormalities were detected on re‐examination 2 weeks post‐surgery.

Functional and Genetic Analyses Unveil the Implication of CDC27 in Hemifacial Microsomia

Hemifacial microsomia (HFM) is a rare congenital genetic syndrome primarily affecting the first and second pharyngeal arches, leading to defects in the mandible, external ear, and middle ear. The pathogenic genes remain largely unidentified. Whole-exome sequencing (WES) was conducted on 12 HFM probands and their unaffected biological parents. Predictive structural analysis of the target gene was conducted using PSIPRED (v3.3) and SWISS-MODEL, while STRING facilitated protein-to-protein interaction predictions. CRISPR/Cas9 was applied for gene knockout in zebrafish. In situ hybridization (ISH) was employed to examine the spatiotemporal expression of the target gene and neural crest cell (NCC) markers. Immunofluorescence with PH3 and TUNEL assays were used to assess cell proliferation and apoptosis. RNA sequencing was performed on mutant and control embryos, with rescue experiments involving target mRNA injections and specific gene knockouts. CDC27 was identified as a novel candidate gene for HFM, with four nonsynonymous de novo variants detected in three unrelated probands. Structural predictions indicated significant alterations in the secondary and tertiary structures of CDC27. cdc27 knockout in zebrafish resulted in craniofacial malformation, spine deformity, and cardiac edema, mirroring typical HFM phenotypes. Abnormalities in somatic cell apoptosis, reduced NCC proliferation in pharyngeal arches, and chondrocyte differentiation issues were observed in cdc27−/− mutants. cdc27 mRNA injections and cdkn1a or tp53 knockout significantly rescued pharyngeal arch cartilage dysplasia, while sox9a mRNA administration partially restored the defective phenotypes. Our findings suggest a functional link between CDC27 and HFM, primarily through the inhibition of CNCC proliferation and disruption of pharyngeal chondrocyte differentiation.

Integration of 3D-printed middle ear models and middle ear prostheses in otosurgical training

BackgroundIn otosurgical training, cadaveric temporal bones are primarily used to provide a realistic tactile experience. However, using cadaveric temporal bones is challenging due to their limited availability, high cost, and potential for infection. Utilizing current three-dimensional (3D) technologies could overcome the limitations associated with cadaveric bones. This study focused on how a 3D-printed middle ear model can be used in otosurgical training.MethodsA cadaveric temporal bone was imaged using microcomputed tomography (micro-CT) to generate a 3D model of the middle ear. The final model was printed from transparent photopolymers using a laser-based 3D printer (vat photopolymerization), yielding a 3D-printed phantom of the external ear canal and middle ear. The feasibility of this phantom for otosurgical training was evaluated through an ossiculoplasty simulation involving ten otosurgeons and ten otolaryngology–head and neck surgery (ORL-HNS) residents. The participants were tasked with drilling, scooping, and placing a 3D-printed partial ossicular replacement prosthesis (PORP). Following the simulation, a questionnaire was used to collect the participants' opinions and feedback.ResultsA transparent photopolymer was deemed suitable for both the middle ear phantom and PORP. The printing procedure was precise, and the anatomical landmarks were recognizable. Based on the evaluations, the phantom had realistic maneuverability, although the haptic feedback during drilling and scooping received some criticism from ORL-HNS residents. Both otosurgeons and ORL-HNS residents were optimistic about the application of these 3D-printed models as training tools.ConclusionsThe 3D-printed middle ear phantom and PORP used in this study can be used for low-threshold training in the future. The integration of 3D-printed models in conventional otosurgical training holds significant promise.

Artificial intelligence-based diagnosis in fetal pathology using external ear shapes.

Here we trained an automatic phenotype assessment tool to recognize syndromic ears in two syndromes in fetuses-=CHARGE and Mandibulo-Facial Dysostosis Guion Almeida type (MFDGA)-versus controls. We trained an automatic model on all profile pictures of children diagnosed with genetically confirmed MFDGA and CHARGE syndromes, and a cohort of control patients, collected from 1981 to 2023 in Necker Hospital (Paris) with a visible external ear. The model consisted in extracting landmarks from photographs of external ears, in applying geometric morphometry methods, and in a classification step using machine learning. The approach was then tested on photographs of two groups of fetuses: controls and fetuses with CHARGE and MFDGA syndromes. The training set contained a total of 1489 ear photographs from 526 children. The validation set contained a total of 51 ear photographs from 51 fetuses. The overall accuracy was 72.6% (58.3%-84.1%, p<0.001), and 76.4%, 74.9%, and 86.2% respectively for CHARGE, control and MFDGA fetuses. The area under the curves were 86.8%, 87.5%, and 90.3% respectively for CHARGE, controls, and MFDGA fetuses. We report the first automatic fetal ear phenotyping model, with satisfactory classification performances. Further validations are required before using this approach as a diagnostic tool.

Novel likely pathogenic variant in the EYA1 gene causing Branchio oto renal syndrome and the exploration of pathogenic mechanisms

ObjectiveBranchio-oto-renal syndrome (BOR, OMIM#113,650) is a rare autosomal dominant disorder that presents with a variety of symptoms, including hearing loss (sensorineural, conductive, or mixed), structural abnormalities affecting the outer, middle, and inner ear, branchial fistulas or cysts, as well as renal abnormalities.This study aims to identify the pathogenic variants by performing genetic testing on a family with Branchio-oto-renal /Branchio-otic (BO, OMIM#602,588) syndrome using whole-exome sequencing, and to explore possible pathogenic mechanisms.MethodsThe family spans 4 generations and consists of 9 individuals, including 4 affected by the BOR/BO syndrome. Phenotypic information, including ear malformation and branchial cleft, was collected from family members. Audiological, temporal bone imaging, and renal ultrasound examinations were also performed. Whole-exome sequencing was conducted to identify candidate pathogenic variants and explore the underlying molecular etiology of BOR/BO syndrome by minigene experiments.ResultsIntra-familial variability was observed in the clinical phenotypes of BOR/BO syndrome in this family. The severity and nature of hearing loss varied in family members, with mixed or sensorineural hearing loss. The proband, in particular, had profound sensorineural hearing loss on the left and moderate conductive hearing loss on the right. Additionally, the proband exhibited developmental delay, and her mother experienced renal failure during pregnancy and terminated the pregnancy prematurely. Genetic testing revealed a novel heterozygous variant NM_000503.6: c.639 + 3 A > C in the EYA1 gene in affected family members. In vitro minigene experiments demonstrated its effect on splicing. According to the American College of Medical Genetics (ACMG) guidelines, this variant was classified as likely pathogenic.ConclusionThis study highlights the phenotypic heterogeneity within the same family, reports the occurrence of renal failure and adverse pregnancy outcomes in a female patient at reproductive age with BOR syndrome, and enriches the mutational spectrum of pathogenic variants in the EYA1 gene.

Epidemiology of congenital malformations of the external ear in Hunan Province, China, from 2016 to 2020.

To describe the epidemiology of congenital malformations of the external ear (CMEE). Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2016 to 2020. The prevalence of CMEEs is defined as the number of cases per 1000 fetuses (births and deaths at 28 weeks of gestation and beyond) (unit: ‰). Prevalence and 95% confidence intervals (CI) were calculated by the log-binomial method. Chi-square trend tests (χ2trend) were used to determine trends in prevalence by year. P < .05 was considered statistically significant. Crude odds ratios (ORs) were calculated to examine the association of sex, residence, and maternal age with CMEEs. Our study included 847,755 fetuses, and 14,459 birth defects were identified, including 1227 CMEEs (accounted for 8.49% of birth defects). The prevalences of birth defects and CMEEs were 17.06‰ (95%CI: 16.78-17.33) and 1.45‰ (95%CI: 1.37-1.53), respectively. A total of 185 microtia-anotias were identified, accounting for 15.08% of CMEEs, with a prevalence of 0.22‰ (95%CI: 0.19-0.25). And 1042 other CMEEs were identified, accounting for 84.92% of CMEEs. From 2016 to 2020, the prevalences of birth defects were 18.20‰, 18.00‰, 16.31‰, 16.03‰, and 16.47‰, respectively, showing a downward trend (χ2trend =8.45, P < .01); the prevalences of CMEEs were 1.19‰, 1.62‰, 1.80‰, 1.21‰, and 1.35‰, respectively, with no significant trend (χ2trend =0.09, P = .77). CMEEs were more common in males than females (1.60‰ vs 1.27‰, OR = 1.26, 95%CI: 1.12-1.41), in urban areas than in rural areas (1.77‰ vs 1.23‰, OR = 1.45, 95%CI: 1.29-1.62). The prevalences of CMEEs for maternal age < 20, 20-24, 25-29, 30-34, and ≥ 35 were 1.75‰, 1.27‰, 1.44‰, 1.47‰, and 1.58‰, respectively, with no significant difference (P > .05, reference: 25-29). Most CMEEs were diagnosed by clinical examinations (92.34%), and most CMEEs were diagnosed postpartum (within 7 days) (96.25%). In summary, we have presented the epidemiology of CMEEs in Hunan Province, China. CMEEs were more common in males than females, in urban areas than rural areas, whereas there was no significant difference in prevalence of CMEEs by maternal age. We inferred that CMEEs may be mainly related to genetics, and the mechanism needs to be examined in the future.

Graft Healing Process Following Cartilage Myringoplasty Without Trimming of the Perforation Margin.

Objective: The objective of this study was to endoscopically evaluate the graft healing process and graft success rate following cartilage myringoplasty, without trimming of the perforation margin or external ear canal (EAC) packing. Material and Methods: Patients with chronic tympanic membrane (TM) perforation underwent endoscope cartilage underlay myringoplasty, without trimming perforation margin or EAC packing. The healing process of the cartilage graft and the graft success rate were evaluated at 6 months postoperatively. Results: Fifty-eight ears were included in this study. At 1 week postoperatively, clinical inosculation and neovascularization of the graft were observed in small- and medium-sized perforations, but not in large or subtotal perforations. At 2 weeks postoperatively, graft clinical inosculation and neovascularization were completed in the small- and medium-sized perforations; however, neovascularization of the graft had only just begun in the large perforations. At 3 weeks postoperatively, completion of the graft clinical inosculation was achieved in 57 of the 58 ears. At 4 weeks postoperatively, complete neovascularization was achieved in all perforations. Of the 58 ears, postoperative infection resulted in residual perforation in 1 ear, and an insufficient graft resulted in residual perforation in a large perforation without infection. Overall, the graft success rate was 96.6% (56/58). There was no correlation between the graft success rate and graft neovascularization score. Conclusions: The graft healing process experienced the dilation of the blood vessels of the remnant TM, graft clinical inosculation, and neovascularization following cartilage myringoplasty without trimming of the perforation margin and EAC packing; however, the graft success rate was not related to the endoscopic graft neovascularization scores.

Adaptations to sociality in the mimetic and auricular musculature of the African wild dog (Lycaon pictus).

The African wild dog (Lycaon pictus) is a highly social canid that engages in sophisticated, coordinated group hunting tactics to procure large game. It is one of the most effective hunters of the African savannah, due to its highly developed communication methods. It also has large, mobile ears which enhance its auditory capabilities while hunting and assist with thermoregulation. Recent research suggested that certain muscles of facial expression, particularly those involved with expressive eyebrow movement, evolved solely in domestic dogs (Canis familiaris) to facilitate communication with their human owners. However, it is unclear whether highly social wild canid species may also employ similar expressive eye communication. We performed detailed dissections of an adult male L. pictus to evaluate and describe its mimetic and auricular musculature. Overall, L. pictus has well-developed facial and ear muscles. Musculi levator anguli oculi medialis (LAOM) and retractor anguli oculi lateralis (RAOL), mimetic muscles of hypothesized importance in domestic dog-human non-verbal communication, are enlarged in L. pictus, comparable in size to those of domestic dogs, as is m. orbicularis oculi. This morphology suggests that ocular facial expressions contribute to within-pack communication in wild dogs and are not unique to domestic dogs. The auricular muscles of L. pictus are well-developed, supporting greater leverage and fine manipulation of its large, mobile ears. These muscular adaptations facilitate the highly social ecology of African wild dogs and challenge current interpretations about the unique nature of domestic dog facial expressions.

Genotype-phenotype associations in microtia: a systematic review

BackgroundMicrotia is a congenital ear malformation that can occur as isolated microtia or as part of a syndrome. The etiology is currently poorly understood, although there is strong evidence that genetics has a role in the occurrence of microtia. This systematic review aimed to determine the genes involved and the abnormalities in microtia patients' head and neck regions.MethodsWe used seven search engines to search all known literature on the genetic and phenotypic variables associated with the development or outcome of microtia. The identified publications were screened and selected based on inclusion and exclusion criteria and assessed for methodological quality using the Joanna Briggs Institute (JBI) critical appraisal tools. We found 40 papers in this systematic review with phenotypic data in microtia involving 1459 patients and 30 articles containing genetic data involved in microtia.ResultThe most common accompanying phenotype of all microtia patients was external ear canal atresia, while the most common head and neck abnormalities were the auricular, mental, and oral regions. The most common syndrome found was craniofacial microsomia syndrome. In the syndromic microtia group, the most common genes were TCOF1 (43.75%), SIX2 (4.69%), and HSPA9 (4.69%), while in the non-syndromic microtia group, the most frequently found gene was GSC exon 2 (25%), FANCB (16.67%), HOXA2 (8.33%), GSC exon 3 (8.33%), MARS1 (8.33%), and CDT1 (8.33%).ConclusionsOur systematic review shows some genes involved in the microtia development, including TCOF1, SIX2, HSPA9, GSC exon 2, FANCB, HOXA2, GSC exon 3, MARS1, and CDT1 genes. We also reveal a genotype-phenotype association in microtia. In addition, further studies with more complete and comprehensive data are needed, including patients with complete data on syndromes, phenotypes, and genotypes.

Contemporary Treatment of Microtia-Atresia.

Microtia-atresia is a congenital deformity affecting the external ear and ear canal that can present with varying degrees of severity and morbidity. Treatment occurs along a spectrum and primarily centers on improving aesthetic appearance. Many cases of microtia will not be effectively treated with conservative measures and will require some form of reconstruction. There are several options available, including porous polyethylene implants, autologous rib grafting, and autologous chondrocyte frameworks. Equally significant is the treatment of hearing loss, as many patients with microtia-atresia will have a component of conductive hearing loss. This article aims to comprehensively review contemporary treatment modalities for microtia-atresia and discuss the advantages, disadvantages, and practicality of each. Treatment and reconstruction often take a multidisciplinary and multistaged approach to achieve optimal results, with ideal management determined by each patient's individualized needs.

Auriculocondylar syndrome 2 caused by a novel PLCB4 variant in a male Chinese neonate: A case report and review of the literature.

Auriculocondylar syndrome (ARCND) is a rare congenital craniofacial developmental malformation syndrome of the first and second pharyngeal arches with external ear malformation at the junction between the lobe and helix, micromaxillary malformation, and mandibular condylar hypoplasia. Four subtypes of ARCND have been described so far, that is, ARCND1 (OMIM # 602483), ARCND2 (ARCND2A, OMIM # 614669; ARCND2B, OMIM # 620458), ARCND3 (OMIM # 615706), and ARCND4 (OMIM # 620457). This study reports a case of ARCND2 resulting from a novel pathogenic variant in the PLCB4 gene, and summarizes PLCB4 gene mutation sites and phenotypes of ARCND2. The proband, a 5-day-old male neonate, was referred to our hospital for respiratory distress. Micrognathia, microstomia, distinctive question mark ears, as well as mandibular condyle hypoplasia were identified. Trio-based whole-exome sequencing identified a novel missense variant of NM_001377142.1:c.1928C>T (NP_001364071.1:p.Ser643Phe) in the PLCB4 gene, which was predicted to impair the local structural stability with a result that the protein function might be affected. From a review of the literature, only 36 patients with PLCB4 gene mutations were retrieved. As with other studies examining familial cases of ARCND2, incomplete penetrance and variable expressivity were observed within different families' heterozygous mutations in PLCB4 gene. Although, motor and intellectual development are in the normal range in the vast majority of patients with ARCND2, long-term follow-up and assessment are still required.

Pathogenic Aspergillus Strains Identification and Antifungal Susceptibility Analysis of 452 Cases with Otomycosis in Jingzhou, China.

To study the distribution of pathogenic Aspergillus strains of otomycosis in central China and the identification of their antifungal sensitivity. We collected external ear canal secretions clinically diagnosed as otomycosis from April 2020 to January 2023 from the Department of Otolaryngology-Head and Neck Surgery in central China. The pathogenic Aspergillus strains were identified through morphological examination and sequencing. The antifungal sensitivity was performed using the broth microdilution method described in the Clinical Laboratory Standard Institute document M38-A3. In the 452 clinical strains isolated from the external ear canal, 284 were identified as Aspergillus terreus (62.83%), 92 as Aspergillus flavus (20.35%), 55 as Aspergillus niger (12.17%). In antifungal susceptibility tests the MIC of Aspergillus strains to bifonazole and clotrimazole was high,all the MIC90 is > 16 ug/mL. However, most Aspergillus isolates show moderate greatly against terbinafine, itraconazole and voriconazole. A. terreus is the most common pathogenic Aspergillus strain in otomycosis in central China. The selected topical antifungal drugs were bifonazole and clotrimazole; the drug resistance rate was approximately 30%. If the infection is persistent and requires systemic treatment, terbinafine and itraconazole can be used. The resistance of Aspergillus in otomycosis to voriconazole should be screened to avoid the systemic spread of infection in immunocompromised people and poor compliance with treatment. However, the pan-azole-resistant strain of Aspergillus should be monitored, particularly in high-risk patients with otomycosis.

Knowledge and Attitude Toward Otitis Externa: A Saudi Arabian Perspective

ABSTRACT Objectives: This study intended to assess the level of awareness and attitude toward otitis externa (OE) and specific limitations that counter the attempts to uplift the understanding and notion related to OE among the general population of Saudi Arabia. Methods: A cross-sectional quantitative study using a questionnaire was done via Google Forms between May 2023 and July 2023. The scoring method was used to determine the participant’s awareness or attitude; participants who scored &gt;50% were considered aware or to have a good attitude. Results: Approximately 52.2% had a good attitude toward the OE, and majority were willing to visit healthcare professionals (81%) to provide care and receive proper education during office visits (80.1%). Of all the participants, 69%, 33.4%, and 30.8% suggested that a lack of awareness, cost, and health insurance, respectively, might prevent patients from seeking a healthcare professional. Only 10.9% of participants demonstrated good awareness (score &gt;13) of outer ear inflammation. Conclusion: The findings indicate a poor level of awareness regarding OE, and a positive attitude toward seeking healthcare, with the majority recommending professional visits and relying on healthcare professionals for information.

Three Common Skin Infections in a Student Athlete and a Subsequent Outbreak of Methicillin-resistant Staphylococcus aureus Skin Infections in a Single Gym: a Case Report

Individuals with frequent physical contact, such as wrestlers, are at an increased risk of developing infectious diseases, including bacterial, viral, and fungal infections. Herein, we report the case of a student wrestler who developed three common skin infections and a subsequent outbreak of methicillin-resistant Staphylococcus aureus (MRSA) skin infections in a single gym. A 14-year-old male presented with a 2-week history of an edematous, painful skin lesion on the left outer ear. He responded poorly to empirical antimicrobial therapy. Examination revealed multiple crusts and oozing on the left ear helix. A solitary, erythematous firm nodule was also observed on the left posterior neck. Bacterial culture confirmed MRSA resistance to clindamycin and tetracycline. Further assessment confirmed the diagnosis of herpes labialis and tinea faciei. Within 3 weeks, six additional cases of MRSA skin infections were reported, all linked to the same wrestling gym. Most patients were effectively treated with oral cephalosporins combined with topical fluoroquinolones and occlusive dressing.

The reliability of remote diagnostic hearing assessment in school-entry-aged children

Objective To explore the feasibility of remote diagnostic hearing testing within schools, for school-entry aged children (4–7 years). Design A prospective cross-sectional comparative study design was used to establish the reliability of remote hearing assessment by comparing traditional face-to-face pure tone audiometry (PTA) with remote PTA, traditional otoscopy with remote video otoscopy and interpretation of tympanograms in-person with remote analysis. Study Sample 464 school-entry year level children from 18 schools. Results Air conduction thresholds established by remote testing were within a clinically acceptable range of ±10 dB HL from traditional thresholds in 98% of cases at 1 kHz and 97.8% at 4 kHz. Bone conduction thresholds varied by ≤10 dB HL in 100% of cases at 1 kHz and 95.7% at 4 kHz. Remote otoscopy and tympanometry interpretation had 78.6% agreement (moderate; κ = 0.6) and 92.2% agreement (almost perfect; κ = 0.9), respectively. Conclusions We found there to be good reliability between face-to-face PTA and remote PTA performed within the school environment. Furthermore, assessment of the outer and middle ear via video otoscopy and remote tympanometry classification were both viable. Remote diagnostic hearing tests in schools can extend reach of paediatric services in rural areas.

Mange in farmed rabbits

In this study we determined occurrence of mange in breeding rabbits on 1368 commercial farms in Portugal and Spain during 1996-2022. We obtained our information by carrying out 11 737 visits to 1334 doe farms, 11 farms only with growers, and 23 artificial insemination (AI) centres. The median size of the visited doe farms was 450 does (minimum to maximum: 100–2500 does) and 1175 does (ranging from100 to 6000 does) in 1996 and 2022, respectively. AI was used on 9% of the farms visited in 1996 and 95% in 2022. For our diagnoses we used (1) clinical observations on all visited farms to detect sarcoptic mange; (2) examination of the outer ear of breeding rabbits on a subset of farms to assess the prevalence of otodectic clinical mange (OCM); and (3) the examination of breeding rabbits and youngstock does (2.5 to 5.5 mo old) on a subset of 72 farms during 2018 to estimate prevalence of body mange compatible with cheyletiellosis. They were mainly clinical diagnoses, supported sometimes by a laboratorial confirmation. Over the course of the 27-yr clinical study, the cumulative incidence of sarcoptic mange was low; we recorded a total of 13 affected doe farms. The percentage of farms affected by OCM dropped from 55% in 1996 to 28% in 2022. OCM mean prevalence for the period 1996-2022 and 95% binomial confidence interval (CI) were 3.2% (95% CI [3.1-3.3%]), and 3.9% (95% CI [3.7-4.1%]) in does and bucks, respectively. We observed an improvement over time; the OCM yearly mean prevalence decreased from 7% in 1996 to 2.3% in 2022 in females and from 7.2% to 2.2% in males, respectively. This progress was compatible with the use of semen coming from AI centres; biosecurity measures and medical management also contributed. Genetic type was predisposing risk factor for OCM. Enabling risk factors were year and season (more affected in summer). Hair and skin disorders along the back, compatible with cheyletiellosis, were also assessed during 2018; we detected 50% of positive farms with various prevalence results in females, males or young does. In this study, we describe protocols observed in the control of benign and severe cases of mange in rabbitries, which included the use of ivermectin and synthetic acaricides. Ivermectin was used on 36% of doe farms visited during 2018-2022; we suggest that it should be used less often to lower its negative impact on the environment.