背景:对β-内酰胺类抗生素的耐药性问题,由ESBL和AmpCβ-内酰胺酶引起,在全球范围内变得更糟。由携带这些酶的细菌分离物引起的感染难以用碳青霉烯类作为此类感染的唯一有效治疗选择来治疗。这项研究的目的是确定从临床标本中分离出的ESBLs和产生AmpC的革兰氏阴性杆菌的频率,并评估头孢吡肟-他唑巴坦组合对它们的敏感性。
方法:这是在2015年2月至2016年1月期间在TheodorBilharz研究所医院对100个革兰氏阴性杆菌进行的观察性横断面研究。ESBL生产通过使用圆盘扩散测试进行筛选,然后通过联合圆盘确认测试进行确认。AmpC生产的筛选是使用头孢西丁圆盘试验进行的,随后通过AmpC光盘测试证实了这一点。研究了对ESBL和/或AmpC产生阳性的分离株对抗生素的敏感性。
结果:在100个革兰氏阴性杆菌中,通过联合圆盘确认测试,在56个分离株中,通过圆盘扩散测试对ESBL产生呈阳性,确认了44个分离株为ESBL产生者。使用头孢西丁圆盘试验评估AmpC生产的存在,筛选出32株为AmpC生产者,AmpC圆盘测试证实了其中9个分离株的AmpC产量。使用Mast®D68C装置,32株是ESBL生产者,3是AmpC生产商,和4个分离株是ESBL/AmpC共生产者。对头孢吡肟-他唑巴坦的敏感性最高(91.48%),其次是碳青霉烯类。
结论:头孢吡肟-他唑巴坦对产生ESBL和/或AmpC的革兰氏阴性杆菌显示出显著的活性,可能被认为是碳青霉烯类抗生素的治疗替代方案。
BACKGROUND: The problem of resistance to beta-lactam antibiotics, which is caused by ESBL and AmpC β-lactamases, is getting worse globally. Infections caused by bacterial isolates harboring these enzymes are difficult to treat with carbapenems being the sole effective treatment option for such infections. The objective of this study was to determine the frequency of ESBLs and AmpC-producing Gram-negative bacilli isolated from clinical specimens and to evaluate the sensitivity of cefepime-tazobactam combination against them.
METHODS: This is an observational cross-sectional study carried out on 100 Gram-negative bacilli at Theodor Bilharz Research Institute Hospital during the period from February 2015 to January 2016. ESBL production was screened by using the disc diffusion test followed by confirmation by the combined disc confirmatory test, the screening for AmpC production was conducted using the cefoxitin disc test, which was subsequently confirmed by the AmpC disc test. Isolates confirmed positive for ESBL and/ or AmpC production were investigated for their susceptibility to antibiotics.
RESULTS: Among 100 Gram-negative bacilli, 44 isolates were confirmed as ESBL producers by the combined disc confirmatory test out of 56 isolates that tested positive for ESBL production through the disc diffusion test. The presence of AmpC production was assessed using the cefoxitin disc test, 32 isolates were screened to be AmpC producers, and the AmpC disc test confirmed AmpC production in 9 isolates of them. Using the Mast® D68C set, 32 isolates were ESBL producers, 3 were AmpC producers, and 4 isolates were ESBL/AmpC co-producers. The highest sensitivity was to cefepime-tazobactam (91.48%) followed by the carbapenems.
CONCLUSIONS: Cefepime-tazobactam showed remarkable activity against ESBL and/or AmpC-producing Gram-negative bacilli and may be considered as a therapeutic alternative to carbapenems.