背景:假单胞菌属于假单胞菌属,可引起各种感染,包括耳朵,皮肤,和软组织感染。耳麦有独特的易感性,对青霉素和头孢菌素敏感,但对碳青霉烯类耐药,由于产生称为POM-1的金属-β-内酰胺酶。这揭示了与铜绿假单胞菌的遗传相似性,这有时会导致错误识别。
方法:我们报告一例70岁的日本男性,他在多发性骨髓瘤化疗期间出现蜂窝织炎和菌血症。他最初接受了美罗培南治疗,但血培养后发现革兰阴性杆菌经基质辅助激光解吸电离-飞行时间质谱(MALDI-TOFMS)鉴定为耳炎。从以前的报告中预测了碳青霉烯耐药性;因此,我们改用左氧氟沙星和头孢吡肟双重治疗,取得了良好的治疗效果。
结论:这是首例报道的免疫功能低下患者中耳炎和菌血症的病例。碳青霉烯类通常用于免疫功能低下的患者,而耳闻假单胞菌通常对其具有抗性。然而,其生化特性与铜绿假单胞菌相似;因此,它的准确识别至关重要。在本研究中,我们使用MALDI-TOFMS快速鉴定出耳炎,并从碳青霉烯类抗生素转向适当的抗菌治疗,导致一个成功的结果。
BACKGROUND: Pseudomonas otitidis belongs to the genus Pseudomonas and causes various infections, including ear, skin, and soft tissue infections. P. otitidis has a unique susceptibility profile, being susceptible to penicillins and cephalosporins but resistant to carbapenems, due to the production of the metallo-β-lactamase called POM-1. This revealed genetic similarities with Pseudomonas aeruginosa, which can sometimes lead to misidentification.
METHODS: We report the
case of a 70-year-old Japanese male who developed cellulitis and bacteremia during chemotherapy for multiple myeloma. He was initially treated with meropenem, but blood culture later revealed gram-negative bacilli identified as P. otitidis using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Carbapenem resistance was predicted from previous
reports; therefore, we switched to dual therapy with levofloxacin and cefepime, and favorable treatment results were obtained.
CONCLUSIONS: This is the first reported
case of P. otitidis cellulitis and bacteremia in an immunocompromised patient. Carbapenems are typically used in immunocompromised patients and P. otitidis is often resistant to it. However, its biochemical properties are similar to those of Pseudomonas aeruginosa; therefore, its accurate identification is critical. In the present study, we rapidly identified P. otitidis using MALDI-TOF MS and switched from carbapenems to an appropriate antimicrobial therapy, resulting in a successful outcome.