Co-infection with Neisseria mucosa in a patient with tuberculous otitis media

Tuberculous otitis media(TOM) is a rare manifestation caused by Mycobacterium tuberculosis with low incidence rates among extrapulmonary tuberculosis cases. Diagnosis is often delayed because of the presence of several clinical manifestations and the high prevalence of secondary bacterial infections. Few reports have attributed secondary bacterial infections in patients with TOM to commensal Neisseria. Thus, understanding the pathogenic mechanisms and clinical features of commensal Neisseria is important, considering its recent presentation as an infection-causing pathogen. Neisseria mucosa is a commensal inhabitant in humans and is generally considered non-pathogenic but can cause infection in rare cases. Here, we report an atypical secondary infection caused by Neisseria mucosa in an 81-year-old woman with TOM being treated for pulmonary tuberculosis. Direct purulent otorrhea smear microscopy revealed no acid-fast bacilli using Ziehl-Neelsen staining, whereas the phagocytosis of gram-negative cocci by white blood cells was confirmed using Gram staining. Otorrhea culture revealed the growth of N. mucosa. Subsequently, M. tuberculosis infection in the otorrhea was identified using a culture-based method. Vigilance is critical for the early detection of TOM to prevent further complications. This report raises awareness regarding TOM and provides insight into the pathogenicity of N. mucosa in otitis media.

Is Dose Adjustment Based on Several Factors of Body Size Descriptors Effective for Prevention of Thrombocytopenia by Linezolid Therapy in Hemodialysis Patients?

Previous study suggested that low body weight was one of the risk factors of thrombocytopenia induced by linezolid in non-hemodialysis patients. However, there have been little investigations for the linezolid-induced thrombocytopenia in hemodialysis patients. This study was to evaluate the association between several factors of body size descriptors and thrombocytopenia in hemodialysis-patients. No factor of body size descriptors showed significant correlation with linezolid-induced thrombocytopenia (patients with thrombocytopenia vs patients without thrombocytopenia: body weight;60.0 kg vs 55.3 kg, p = 0.82: body mass indices;21.1 kg/m2 vs 21.2 mg/m2, p = 0.44: ideal body weight;61.2 kg vs 59.5 kg, p = 0.21: lean body weight;50.1 kg vs 45.7 kg, p = 0.64: dosage amount;20.0 mg/kg vs 21.7 mg/kg, p = 0.74: body surface area;1.65 m2 vs 1.54 m2, p = 0.43). There were not significant differences in the body size descriptors between linezolid therapy for more than 14 days and for less than 13 days (more than 14 days vs less than 13 days: body weight;53.5 kg vs 56.8 kg, p = 0.75: body mass indices;20.9 kg/m2 vs 21.1 mg/m2, p = 0.47: ideal body weight;60.3 kg vs 59.9 kg, p = 0.17: lean body weight;44.3 kg vs 47.7 kg, p = 0.56: dosage amount;22.4 mg/kg vs 21.1 mg/kg, p = 0.67: body surface area;1.51 m2 vs 1.59 m2, p = 0.37). Our data suggested that dosage adjustment of linezolid based on body weight was not recommended in hemodialysis-patients.