Ben Hassen A, Fournier G, Kechrid A, Fendri C, Ben Redjeb S, Philippon A
Service de Microbiologie, Hôpital Charles-Nicolle, Tunis.
Pathol Biol (Paris). 1990 May;38(5):464-9.
The enzymatic and plasmid-encoded resistance towards oxyimino-beta-lactams has been recently reported as related to the production of an extended-spectrum beta-lactamase (e.g. SHV-2, CTX-1 or TEM-3), in particular in our hospital since 1984. The prevalence of that resistance has been examined from January 1984 to December 1988 in function of specimen, unit and type of enzyme among 8,421 isolates of Klebsiella spp., E. coli, Salmonella spp. Each isolate showing a diameter of inhibition zone size inferior or equal to 25 mm for cefotaxime, the double disk synergy test was performed between a disk of amoxicillin and a clavulanic acid disk of cefotaxime, ceftriaxone, ceftazidime and aztreonam. In case of synergy, sonicated extracts have been prepared and examined by isoelectrofocusing with the detection of beta-lactamase activity by ceftriaxone and nitrocefin. 56 isolates (K. pneumoniae, K. oxytoca, E. coli, S. wien, S. typhimurium scored positive including 27 in pediatrics, 18 in surgery, and 8 in medicine. 41% of isolates have been obtained from blood cultures and 26.8% from urines. A majority of isolates (49/56) produced the SHV-2 type, but other types mediating the resistance phenotype CTX have been individualized initially by their isoelectric points e.g. 5.4 (TEM-20 in K. pneumoniae in July 1986), 6.4 (TEM-21 in E. coli, 1 K. pneumoniae in July 1988). The prevalence of resistance to cefotaxime from 1984 to 1988 has increased (from 0.3 to 1.4%), the highest rate being observed in pediatrics (5.6% in 1984 and 22.1% in 1988).
最近有报道称，对氧亚氨基β-内酰胺类药物的酶促和质粒编码耐药性与超广谱β-内酰胺酶（如SHV-2、CTX-1或TEM-3）的产生有关，自1984年以来在我们医院尤其如此。1984年1月至1988年12月期间，对8421株克雷伯菌属、大肠杆菌、沙门菌属菌株，根据标本、科室和酶的类型，对这种耐药性的流行情况进行了调查。对于头孢噻肟，每个抑菌圈直径小于或等于25mm的分离株，在阿莫西林纸片和头孢噻肟、头孢曲松、头孢他啶及氨曲南的克拉维酸纸片之间进行双纸片协同试验。出现协同作用时，制备超声提取物，并通过等电聚焦进行检测，同时用头孢曲松和硝基头孢菌素检测β-内酰胺酶活性。56株分离株（肺炎克雷伯菌、产酸克雷伯菌、大肠杆菌、维也纳沙门菌、鼠伤寒沙门菌）检测呈阳性，其中儿科27株，外科18株，内科8株。41%的分离株来自血培养，26.8%来自尿液。大多数分离株（49/56）产生SHV-2型，但其他介导耐药表型CTX的类型最初是通过其等电点确定的，例如5.4（1986年7月肺炎克雷伯菌中的TEM-20）、6.4（1988年7月大肠杆菌中的TEM-21，1株肺炎克雷伯菌）。1984年至1988年对头孢噻肟的耐药率有所上升（从0.3%升至1.4%），儿科的耐药率最高（1984年为5.6%，1988年为22.1%）。
