ObjectiveTo study the distributions of virulence genes of Klebsiella pneumoniae (KP) and the distribution of hypervirulent KP (HvKP), and assess the performance of a single gene to predict HvKP.MethodsPolymerase chain reaction (PCR) method was used to analyze 12 virulence-related genes (entB, irp2, iroN, iucA, mrkD, fimH, c-rmpA, p-rmpA2, p-rmpA, wzy-K1, allS and peg-344) and drug-resistance gene blaKPC among 376 clinical KP strains collected from January 2016 to December 2018. Sequence types (ST) of KP were determined after sequencing and comparison, following the detection of 7 house-keeping genes (gapA, infB, mdh, pgi, phoE, rpoB and tonB) by PCR method. Statistical analyses were made for the distributions of virulence genes of KP and the distribution of HvKP with GraphPad Prism 8 software.ResultsAmong the 376 KP strains, the positive rates of entB, irp2, iroN, iucA, mrkD, fimH, c-rmpA, p-rmpA2, p-rmpA, wzy-K1, allS and peg-344 were 100.0%, 76.9%, 22.1%, 28.2%, 97.6%, 97.1%, 1.6%, 24.5%, 21.0%, 7.4%, 4.8% and 31.6%, respectively. The positive rates of the aforementioned virulence genes in the blaKPC-positive group (n=167) were 100.0%, 94.0%, 7.2%, 16.8%, 97.0%, 96.4%, 0.0%, 15.0%, 6.6%, 0.0%, 0.0% and 21.0%, respectively, and those in the blaKPC-negative group (n=209) were 100.0%, 63.2%, 34.0%, 37.3%, 98.1%, 97.6%, 2.9%, 32.1%, 32.5%, 13.4%, 8.6% and 40.2%, respectively; there was no statistically significant difference in entB, mrkD or fimH between the two groups (P>0.05), the positive rate of irp2 was higher in the blaKPC-positive group than that in the blaKPC-negative group (P<0.05), and the positive rates of the rest virulence-related genes were lower in the blaKPC-positive group than those in the blaKPC-negative group (P<0.05). The rate of HvKP in the blaKPC-negative group was higher than that in the blaKPC-positive group (38.3% vs. 18.0%, P<0.05). As a marker of HvKP, iucA showed high sensitivity and specificity (90.9% and 97.7%), followed by p-rmpA2 (83.6% and 100.0%) and iroN (73.6% and 99.2%). ST11 accounted for 87.4% in the blaKPC-positive group, while ST23, ST20, ST54 and ST29 were the four primary types in the blaKPC-negative group, accounting for 23.4% totally.ConclusionsDifferent virulence genes mean different distributions in KP. blaKPC-negative KP is more virulent than blaKPC-positive KP. iucA and p-rmpA2 could serve as good predicators of HvKP. Armed with extreme virulence and drug-resistance, blaKPC-positive HvKP is of great clinical concern.
目的 了解2011年四川大学华西第二医院临床分离菌对常见抗菌药物的耐药性。 方法 采用法国生物梅里埃公司VITEK 2 COMPACT全自动细菌鉴定药敏仪，以及ATB 手工药敏条检测临床分离菌对各种常用抗菌药物的耐药性，参照CLSI 2011年版标准判定药敏试验结果，并用WHONET5.4软件统计分析。 结果 临床分离的1 692株细菌中，G+菌占28.0%（473/1 692），G?菌占72.0%（1 219/1 692）。分离的前5位病原菌分别为大肠埃希菌、流感嗜血杆菌、肺炎克雷伯菌、肺炎链球菌、金黄色葡萄球菌。耐甲氧西林金黄色葡萄球菌和耐甲氧西林的凝固酶阴性葡萄球菌分别占金黄色葡萄球菌和凝固酶阴性葡萄球菌的15.1%（22/146）和76.7%（46/60），未检出万古霉素、利奈唑胺耐药株。屎肠球菌对所测抗菌药物的耐药性显著高于粪肠球菌，对氨苄西林的耐药率分别为95.7%和13.3%，高水平氨基糖苷类抗生素耐药屎肠球菌和粪肠球菌的耐药率分别为82.6%和30.0%，检出1株对万古霉素耐药的屎肠球菌，未发现对利奈唑胺耐药菌株。青霉素耐药的肺炎链球菌占4.0%（6/151），肺炎链球菌对红霉素、克林霉素、四环素、复方磺胺的耐药率均高于90%。流感嗜血杆菌、副流感嗜血杆菌以及卡他布兰汉菌产β内酰胺酶的比例分别为58.1%（175/301）、70.0%（21/30）、75.9%（22/29）。肠杆菌细菌中产超广谱β内酰胺酶的大肠埃希菌和肺炎克雷伯菌检出率分别为59.9%和74.1%，耐药率最低的分别是3种碳青酶烯类抗生素和阿米卡星。不发酵糖G?杆菌在分离病原菌中所占比例较低，为12.1%（148/1 692），主要为鲍曼不动杆菌和铜绿假单胞，药敏结果显示，除铜绿假单胞对复方磺胺耐药率为93.5%和鲍曼不动杆菌对氨曲南耐药率为38.9%外，该两种细菌对所测抗生素敏感性高，均在80%以上，未检出泛耐药细菌。 结论 定期进行细菌耐药性监测有助于了解医院细菌耐药性变迁，对指导医院合理应用抗菌药物有重要意义。
Objective To probe the distribution and drug resistance of pathogens causing surgical site infection in patients after gynecologic operation, and provide reference for prevention and treatment. Methods Seventy patients with incision infection after gynecologic operation in West China Second University Hospital of Sichuan University from January 2010 to May 2015 were selected. Species of the pathogens from the submitted specimens and the results of the drug susceptibility testing were analyzed. Results Seventy-two strains of pathogens were isolated, including 36 strains (50.0%) of Gram-negative (G–) bacteria and 36 strains (50.0%) of Gram-positive (G+) bacteria. The main G– bacteria were Escherichia coli (36.1%) and Enterobacter cloacae (5.6%); the main G+ bacteria were Staphylococcus aureus (18.1%), Staphylococcus epidermidis (12.5%), and Enterococcus faecalis (8.3%). Escherichia coli showed low sensitivities to ampicillin, ceftriaxone, and gentamicin, with resistance rates of 76.9%, 61.5%, and 61.5%, respectively. Staphylococcus aureus showed low sensitivities to penicillin G, clindamycin, and erythromycin, with resistance rates of 92.3%, 69.2%, and 61.5%, respectively. Staphylococcus epidermidis showed low sensitivities to erythromycin, penicillin G, and ciprofloxacin, with resistance rates of 88.9%, 77.8%, and 77.8%, respectively. No carbapenem-resistant G– bacteria or vancomycin-resistant G+ bacteria were detected. Conclusion Postoperative surgical site infection is the most common nosocomial infection. The main bacteria related to postoperative incision infection in the gynecology department of the hospital are Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecalis, which become resistant to common antibiotics currently. Therefore more attention should be paid to bacterial isolation and drug susceptibility test results for rational use of antimicrobial drugs and effectiveness of the treatment to nosocomial infection.