产后感染病原菌耐药性及危险因素分析

Distribution of pathogens causing postpartum infections and risk factors

目的分析产妇产后感染相关因素和病原菌分布及耐药机制,为产后感染预防和治疗提供依据。方法收集锦州地区2014年1月-2018年6月分娩的2 400例产妇的临床资料。无菌操作收集标本,全自动微生物鉴定系统鉴定菌种。K-B纸片法,对主要分离菌进行药敏试验,参照CLSI标准判断药敏结果。PCR检测金黄色葡萄球菌blaZ、mecA和femA等耐药基因。对患者年龄、分娩方式、产次、产程和是否产后出血等进行统计分析。结果 2 400例产妇85例出现产后感染,感染率3.54%。手术切口感染、呼吸系统感染、生殖道感染、泌尿系统感染和消化系统感染分别为24例(28.24%)、21例(24.71%)、18例(21.18%)、16例(18.82%)和6例(7.06%)。共培养出病原菌90株,其中革兰阳性菌46株(51.11%),革兰阴性菌42株(46.67%),真菌2株(2.22%)。金黄色葡萄球菌对克林霉素、青霉素G、头孢他啶、庆大霉素、妥布霉素、阿米卡星、四环素、左旋氧氟沙星、加替沙星、利福平和万古霉素的耐药率分别为28.57%、38.10%、33.33%、28.57%、19.05%、4.76%、33.33%、23.81%、9.52%、9.52%和0%。草绿色链球菌、粪肠球菌、大肠埃希菌、铜绿假单胞菌和肺炎克雷伯菌对四环素类药物呈高度耐药,对头孢类、青霉素、氨基糖类和喹诺酮类抗生素存在不同程度耐药。金黄色葡萄球菌检出12种耐药基因:blaZ(6株),mecA(1株),femA(2株),pbp 1(2株),ermA(5株),ermB(1株),tetM(6株),tetO(2株),gyrA(5株),fexA(3株)aacA-aphD(2株)和aac(6')-aph(2'')(4株)。分娩方式、产程、医源性操作不当和产后出血与产后感染相关(P<0.05),年龄、产次与产后感染无相关(P>0.05)。讨论产妇产后抵抗力下降易发感染,产后感染的病原菌类型和耐药性有一定特征。产后感染预防宜针对高危因素进行有效干预,根据药敏结果进行治疗。

Objective To analyze factors related to development of a postpartum infection, the distribution of pathogens, and their mechanisms of drug resistance in order to provide evidence for the prevention and treatment of postpartum infections. Methods Clinical data were collected on 2,400 pregnant women who delivered in Obstetrics and Gynecology in Jinzhou from January 2014 to June 2018. Drug susceptibility tests of Staphylococcus aureus, Streptococcus grass, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae were performed using the K-B disc method and CLSI interpretive criteria. Drug resistance genes of S. aureus, such as blaZ, mecA, and femA, were detected using PCR. Clinical data on age, form of delivery, parity, course of labor, and whether or not a postpartum hemorrhage occurred were analyzed. Results Of 2,400 pregnant women, 85 developed a postpartum infection for a rate of infection of 3.54%. Twenty-four patients(28.24%) had a surgical site infection, 21(24.71%) had a respiratory infection, 18(21.18%) had a reproductive tract infection, 16(18.82%) had a urinary tract infection, and 6(7.06%) had a digestive tract infection. Ninety pathogens were cultured, 46 Gram-positive bacteria(51.11%), 42 Gram-negative bacteria(46.67%) and 2 Fungi(2.22%). S. aureus was resistant to clindamycin at a rate of 28.57%, to penicillin G at a rate of 38.10%, to ceftazidime at a rate of 33.33%, to gentamicin at a rate of 28.57%, to tobramycin at a rate of 19.05%, to amikacin at a rate of 4.76%, to tetracycline at a rate of 33.33%, to levofloxacin at a rate of 23.81%, to gatifloxacin at a rate of 9.52%, to rifampicin at a rate of 9.52%, and to vancomycin at a rate of 0%. S. viride, E. faecalis, E. coli, P. aeruginosa, and K. pneumoniae were highly resistant to tetracyclines and were resistant to cephalosporins, penicillins, aminoglycosides, and quinolones to differing degrees. S. aureus was tested for 12 common drug resistance genes. blaZ was detected in 6 strains, mecA was detected in 1, femA was detected in 2, PBP 1 was detected in 2, ermA was detected in 5, ermB was detected in 1, tetM was detected in 6, tetO was detected in 2, gyrA was detected in 5, fexA was detected in 3, aacA-aphD was detected in 2, and AAC(6’-aph(2’) was detected in 4. Factors correlated with a postpartum infection were the form of delivery, course of labor, improper procedure, and postpartum hemorrhage(P<0.05), while age and parity were not correlated with a postpartum infection(P>0.05). Conclusion Puerperal women have decreased resistant after delivery and are susceptible to infections. The types of pathogens causing a postpartum infection and their drug resistance had certain characteristics. Risk factors for a postpartum infection need to dealt with effectively based on the results of drug susceptibility testing.