Ford Mary B, Mende Katrin, Kaiser Susan J, Beckius Miriam L, Lu Dan, Stam Jason, Li Ping, Stewart Laveta, Tribble David R, Blyth Dana M
Brooke Army Medical Center, JBSA Fort Sam Houston, TX 78234, USA.
Infectious Disease Clinical Research Program, Department ofPreventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
Mil Med. 2022 Mar 28;187(3-4):426-434. doi: 10.1093/milmed/usab259.
Multidrug-resistant (MDR) Gram-negative infections complicate care of combat casualties. We describe the clinical characteristics, resistance patterns, and outcomes of Pseudomonas aeruginosa infections in combat casualties.
Combat casualties included in the Trauma Infectious Disease Outcomes Study with infections with and without P. aeruginosa isolation during initial hospitalization were compared. Pseudomonas aeruginosa from initial wound, blood, and serial isolates (≥7 days from previous isolate) collected from June 2009 through February 2014 was subjected to antimicrobial susceptibility testing, pulsed-field gel electrophoresis, and whole genome sequencing for assessing clonality. Multidrug resistance was determined using the CDC National Healthcare Safety Network definition.
Of 829 combat casualties with infections diagnosed during initial hospitalization, 143 (17%) had P. aeruginosa isolated. Those with P. aeruginosa were more severely injured (median Injury Severity Score 33 [interquartile range (IQR) 27-45] vs 30 [IQR 18.5-42]; P < .001), had longer hospitalizations (median 58.5 [IQR 43-95] vs 38 [IQR 26-56] days; P < .001), and higher mortality (6.9% vs 1.5%; P < .001) than those with other organisms. Thirty-nine patients had serial P. aeruginosa isolation (median 2 subsequent isolates; IQR: 1-5), with decreasing antimicrobial susceptibility. Ten percent of P. aeruginosa isolates were MDR, associated with prior exposure to antipseudomonal antibiotics (P = .002), with amikacin and colistin remaining the most effective antimicrobials. Novel antimicrobials targeting MDR Gram-negative organisms were also examined, and 100% of the MDR P. aeruginosa isolates were resistant to imipenem/relabactam, while ceftazidime/avibactam and ceftolozane/tazobactam were active against 35% and 56% of the isolates, respectively. We identified two previously unrecognized P. aeruginosa outbreaks involving 13 patients.
Pseudomonas aeruginosa continues to be a major cause of morbidity, affecting severely injured combat casualties, with emergent antimicrobial resistance upon serial isolation. Among MDR P. aeruginosa, active antimicrobials remain the oldest and most toxic. Despite ongoing efforts, outbreaks are still noted, reinforcing the crucial role of antimicrobial stewardship and infection control.
耐多药革兰氏阴性菌感染使战斗伤员的治疗变得复杂。我们描述了战斗伤员中铜绿假单胞菌感染的临床特征、耐药模式及转归。
比较创伤感染性疾病转归研究中初始住院期间有或无铜绿假单胞菌分离的战斗伤员。对2009年6月至2014年2月收集的初始伤口、血液及系列分离株（距上次分离株≥7天）中的铜绿假单胞菌进行药敏试验、脉冲场凝胶电泳及全基因组测序以评估克隆性。采用美国疾病控制与预防中心国家医疗安全网络的定义确定耐多药情况。
在初始住院期间诊断为感染的829名战斗伤员中，143例（17%）分离出铜绿假单胞菌。分离出铜绿假单胞菌的伤员受伤更严重（损伤严重度评分中位数33[四分位间距（IQR）27 - 45] vs 30[IQR 18.5 - 42]；P <.001），住院时间更长（中位数58.5[IQR 43 - 95] vs 38[IQR 26 - 56]天；P <.001），死亡率更高（6.9% vs 1.5%；P <.001）。39例患者有系列铜绿假单胞菌分离（中位数为后续2株分离株；IQR：1 - 5），药敏性降低。10%的铜绿假单胞菌分离株为耐多药，与先前使用抗假单胞菌抗生素有关（P =.002），阿米卡星和黏菌素仍是最有效的抗菌药物。还检测了针对耐多药革兰氏阴性菌的新型抗菌药物，100%的耐多药铜绿假单胞菌分离株对亚胺培南/雷利巴坦耐药，而头孢他啶/阿维巴坦和头孢洛扎/他唑巴坦分别对35%和56%的分离株有活性。我们识别出两起涉及13名患者的此前未被认识的铜绿假单胞菌暴发。
铜绿假单胞菌仍是发病的主要原因，影响重伤的战斗伤员，系列分离时出现新的耐药性。在耐多药铜绿假单胞菌中，有效的抗菌药物仍是最古老且毒性最大的。尽管不断努力，仍有暴发发生，这强化了抗菌药物管理和感染控制的关键作用。
