Soria-Segarra C, Delgado-Valverde M, Serrano-García M L, López-Hernández I, Navarro-Marí J M, Gutiérrez-Fernández J
José Gutiérrez-Fernández. Laboratorio de Microbiología. Hospital Universitario Virgen de las Nieves. Avenida de las Fuerzas Armadas, 2, E-18014, Granada, Spain.
Rev Esp Quimioter. 2021 Oct;34(5):450-458. doi: 10.37201/req/021.2021. Epub 2021 Jun 8.
Because there are few studies on the clinical implications of colonization by carbapenem-resistant gram-negative bacteria (CRB) this was analyzed in rectal smears (RS) and pharyngeals (PS) and its ability to predict infection/colonization.
A cross-sectional, retrospective study from adult inpatients between January 2016 and December 2019 was conducted. The isolates were characterized by MicroScan and spectrometry of masses applying EUCAST 2018 cutoff points. The detection of carbapenemases was performed by PCR and Sanger sequencing; sequencies was assigned by MLST. The genetic relationship between the clinical isolates was made by pulsed field electrophoresis using the enzymes Xbal, Spel or Apal.
A total of 308 (86.03%) RS and 50 (13.97%) positive PS were detected, the RS had a 85% sensibility, 100% specificity, 100% positive predictive value and 97% negative predictive value. In RS, the following were isolated: 44% (n=135) Acinetobacter baumannii, 26% (n =80) Enterobacterales (20 KPC, 29 OXA-48, 22 VIM, 2 IMP, 7 NDM), 17% (n=53) Pseudomonas aeruginosa and 13% (n=40) Stenotrophomonas maltophilia. In the PS were isolated 44% (n=22) S. maltophilia, 40% (n = 20) A. baumannii, 8% (n=4) P. aeruginosa and 8% (n=4) Enterobacterales (3 VIM, 1 OXA). From the patients with simultaneous RS and PS, 41 (40.6%) had positivity in both smears, 45 (44.6%) only in RS and 15 (14.9%) only in PS. Colonization preceded infection in 81.3% (n=13) of the isolates; association between infection and colonization was found (p<0.001; χ2); and the episodes where the information was found all the isolates from the clinical samples and from the smears were similar.
The probability of predicting infection through the CRB colonized in different clinical samples is feasible. The RS has a major sensibility to detect colonization.
由于关于耐碳青霉烯革兰氏阴性菌（CRB）定植的临床意义的研究较少，因此对直肠涂片（RS）和咽拭子（PS）进行了分析，并评估其预测感染/定植的能力。
对2016年1月至2019年12月期间的成年住院患者进行了一项横断面回顾性研究。分离株通过MicroScan和应用EUCAST 2018临界值的质谱分析法进行鉴定。通过PCR和桑格测序检测碳青霉烯酶；序列通过多位点序列分型（MLST）进行分型。使用Xbal、Spel或Apal酶通过脉冲场凝胶电泳确定临床分离株之间的遗传关系。
共检测到308份（86.03%）RS阳性和50份（13.97%）PS阳性，RS的敏感性为85%，特异性为100%，阳性预测值为100%，阴性预测值为97%。在RS中，分离出以下菌株：44%（n = 135）鲍曼不动杆菌、26%（n = 80）肠杆菌科细菌（20株KPC、29株OXA - 48、22株VIM、2株IMP、7株NDM）、17%（n = 53）铜绿假单胞菌和13%（n = 40）嗜麦芽窄食单胞菌。在PS中，分离出44%（n = 22）嗜麦芽窄食单胞菌、40%（n = 20）鲍曼不动杆菌、8%（n = 4）铜绿假单胞菌和8%（n = 4）肠杆菌科细菌（3株VIM、1株OXA）。在同时进行RS和PS检测的患者中，41例（40.6%）两种涂片均为阳性，45例（44.6%）仅RS阳性，15例（14.9%）仅PS阳性。81.3%（n = 13）的分离株定植先于感染；发现感染与定植之间存在关联（p < 0.001；χ²检验）；并且在所有可获取信息的病例中，临床样本和涂片的所有分离株均相似。
通过不同临床样本中定植的CRB预测感染的可能性是可行的。RS对检测定植具有更高的敏感性。
