Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina, USA.
Department of Surgery, University of North Carolina, Chapel Hill, North Carolina, USA.
Antimicrob Agents Chemother. 2022 Sep 20;66(9):e0068822. doi: 10.1128/aac.00688-22. Epub 2022 Sep 6.
Patients with burn injuries are at high risk for infectious complications, and infections are the most common cause of death after the first 72 h of hospitalization. Hospital-acquired infections caused by multidrug resistant (MDR) Gram-negative bacteria (GNB) in this population are concerning. Here, we evaluated carriage with MDR GNB in patients in a large tertiary-care burn intensive care unit. Twenty-nine patients in the burn unit were screened for intestinal carriage. Samples were cultured on selective media. Median time from admission to the burn unit to first sample collection was 9 days (IQR 5 - 17 days). In 21 (72%) patients, MDR GNB were recovered; the most common bacterial species isolated was Pseudomonas aeruginosa, which was found in 11/29 (38%) of patients. Two of these patients later developed bloodstream infections with P. aeruginosa. Transmission of KPC-31-producing ST22 Citrobacter freundii was detected. Samples from two patients grew genetically similar C. freundii isolates that were resistant to ceftazidime-avibactam. On analysis of whole-genome sequencing, was part of a Tn transposon that was present on two different plasmids in each C. freundii isolate. Plasmid curing experiments showed that removal of both copies of was required to restore susceptibility to ceftazidime-avibactam. In summary, MDR GNB colonization is common in burn patients and patient-to-patient transmission of highly resistant GNB occurs. These results emphasize the ongoing need for infection prevention and antimicrobial stewardship efforts in this highly vulnerable population.
烧伤患者感染并发症的风险很高，感染是烧伤后住院前 72 小时内死亡的最常见原因。该人群中由耐多药（MDR）革兰氏阴性菌（GNB）引起的医院获得性感染令人担忧。在这里，我们评估了大型三级烧伤重症监护病房患者的 MDR GNB 携带情况。对烧伤病房的 29 名患者进行了肠道携带检测。对样本进行了选择性培养。从烧伤病房入院到第一次采样的中位时间为 9 天（IQR 5-17 天）。在 21 名（72%）患者中回收了 MDR GNB；分离出的最常见细菌是铜绿假单胞菌，在 29 名患者中的 11 名（38%）中发现了这种细菌。其中两名患者后来发生了铜绿假单胞菌血流感染。检测到携带 KPC-31 的产 ST22 弗氏柠檬酸杆菌的传播。两名患者的样本均生长出对头孢他啶-阿维巴坦耐药的遗传相似弗氏柠檬酸杆菌分离株。全基因组测序分析表明，位于两个不同质粒上的 Tn 转座子上存在。质粒消除实验表明，需要去除两个拷贝的才能恢复对头孢他啶-阿维巴坦的敏感性。总之，烧伤患者中 MDR GNB 定植很常见，并且高度耐药的 GNB 会在患者之间传播。这些结果强调了在这个高度脆弱的人群中持续需要进行感染预防和抗菌药物管理工作。
