Gajul Shivali V, Mohite Shivajirao T, Mangalgi Smita S, Wavare Sanjay M, Kakade Satish V
Department of Microbiology, Krishna Institute of Medical Sciences, Karad, Maharashtra, India.
Department of Microbiology, BLDEU's Shri BM Patil Medical College, Bijapur, Karnataka, India.
J Lab Physicians. 2015 Jan-Jun;7(1):32-7. doi: 10.4103/0974-2727.151689.
β-lactamases viz., extended spectrum β-lactamase (ESBL), AmpC, and metallo β-lactamase (MBL) production in Klebsiella pneumoniae has led to a serious concern about septicemic neonates in Neonatal Intensive Care Units due to high resistance against commonly used antimicrobials.
To study the prevalence of ESBL, AmpC, and MBL production in K. pneumoniae isolates in neonatal septicemia, to check antimicrobial susceptibility to various drugs including tigecycline; and to assess burden of multiple drug resistance (MDR).
Total 24 clinical isolates of K. pneumoniae isolated from 318 blood samples of suspected cases of neonatal septicemia were studied. Isolates were screened for ESBL, AmpC, and MBL production by Clinical and Laboratory Standards Institute (CLSI) disk method, AmpC cefoxitin screen, and imipenem, meropenem, ceftazidime disk screen respectively; and confirmation was done by CLSI phenotypic disk confirmatory test, AmpC sterile disk method, and imipenem ethylenediamine tetracetic acid double disk synergy test respectively. Antimicrobial susceptibility was determined by Kirby-Bauer's disk diffusion method. Efficacy of tigecycline was evaluated using United States Food and Drug Administration guidelines.
Of the 24 K. pneumoniae isolates, co-production of AmpC + MBL was found in more number of isolates (67%) (P < 0.0001) compared to single enzyme production (ESBL and MBL 8% both, AmpC 12.5%). Rate of resistance for penicillins and cephalosporins was highest. Susceptibility was more for imipenem, co-trimoxazole, and meropenem. Nonsusceptibility to tigecycline was low (21%). A total of 23 (96%) isolates were MDR.
Routine detection of ESBL, AmpC, and MBL is required in laboratories. Carbapenems should be kept as a last resort drugs. Trend of tigecycline susceptibility has been noted in the study. Continued monitoring of susceptibility pattern is necessary to detect true burden of resistance for proper management.
肺炎克雷伯菌产生的β-内酰胺酶，即超广谱β-内酰胺酶（ESBL）、AmpC酶和金属β-内酰胺酶（MBL），由于对常用抗菌药物具有高度耐药性，已引起新生儿重症监护病房对败血症新生儿的严重关注。
研究新生儿败血症中肺炎克雷伯菌分离株中ESBL、AmpC和MBL的产生率，检测对包括替加环素在内的各种药物的抗菌敏感性；并评估多重耐药（MDR）负担。
研究了从318例疑似新生儿败血症病例的血样中分离出的24株肺炎克雷伯菌临床分离株。分别采用临床和实验室标准协会（CLSI）纸片法、AmpC头孢西丁筛选试验以及亚胺培南、美罗培南、头孢他啶纸片筛选试验对分离株进行ESBL、AmpC和MBL产生情况的筛选；并分别通过CLSI表型纸片确证试验、AmpC无菌纸片法以及亚胺培南乙二胺四乙酸双纸片协同试验进行确证。采用 Kirby-Bauer纸片扩散法测定抗菌敏感性。根据美国食品药品监督管理局指南评估替加环素的疗效。
在24株肺炎克雷伯菌分离株中，与单一酶产生（ESBL和MBL均为8%，AmpC为12.5%）相比，发现更多分离株（67%）同时产生AmpC + MBL（P < 0.0001）。青霉素类和头孢菌素类的耐药率最高。亚胺培南、复方新诺明和美罗培南的敏感性较高。对替加环素的不敏感性较低（21%）。共有23株（96%）分离株为多重耐药。
实验室需要常规检测ESBL、AmpC和MBL。碳青霉烯类药物应留作最后使用的药物。本研究中已注意到替加环素敏感性的趋势。持续监测药敏模式对于检测真正的耐药负担以进行适当管理是必要的。
