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.
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.
目的 了解2011年四川大學華西第二醫院臨床分離菌對常見抗菌藥物的耐藥性。 方法 采用法國生物梅里埃公司VITEK 2 COMPACT全自動細菌鑒定藥敏儀，以及ATB 手工藥敏條檢測臨床分離菌對各種常用抗菌藥物的耐藥性，參照CLSI 2011年版標準判定藥敏試驗結果，并用WHONET5.4軟件統計分析。 結果 臨床分離的1 692株細菌中，G+菌占28.0%（473/1 692），G?菌占72.0%（1 219/1 692）。分離的前5位病原菌分別為大腸埃希菌、流感嗜血桿菌、肺炎克雷伯菌、肺炎鏈球菌、金黃色葡萄球菌。耐甲氧西林金黃色葡萄球菌和耐甲氧西林的凝固酶陰性葡萄球菌分別占金黃色葡萄球菌和凝固酶陰性葡萄球菌的15.1%（22/146）和76.7%（46/60），未檢出萬古霉素、利奈唑胺耐藥株。屎腸球菌對所測抗菌藥物的耐藥性顯著高于糞腸球菌，對氨芐西林的耐藥率分別為95.7%和13.3%，高水平氨基糖苷類抗生素耐藥屎腸球菌和糞腸球菌的耐藥率分別為82.6%和30.0%，檢出1株對萬古霉素耐藥的屎腸球菌，未發現對利奈唑胺耐藥菌株。青霉素耐藥的肺炎鏈球菌占4.0%（6/151），肺炎鏈球菌對紅霉素、克林霉素、四環素、復方磺胺的耐藥率均高于90%。流感嗜血桿菌、副流感嗜血桿菌以及卡他布蘭漢菌產β內酰胺酶的比例分別為58.1%（175/301）、70.0%（21/30）、75.9%（22/29）。腸桿菌細菌中產超廣譜β內酰胺酶的大腸埃希菌和肺炎克雷伯菌檢出率分別為59.9%和74.1%，耐藥率最低的分別是3種碳青酶烯類抗生素和阿米卡星。不發酵糖G?桿菌在分離病原菌中所占比例較低，為12.1%（148/1 692），主要為鮑曼不動桿菌和銅綠假單胞，藥敏結果顯示，除銅綠假單胞對復方磺胺耐藥率為93.5%和鮑曼不動桿菌對氨曲南耐藥率為38.9%外，該兩種細菌對所測抗生素敏感性高，均在80%以上，未檢出泛耐藥細菌。 結論 定期進行細菌耐藥性監測有助于了解醫院細菌耐藥性變遷，對指導醫院合理應用抗菌藥物有重要意義。