Vahaboglu H, Hall L M, Mulazimoglu L, Dodanli S, Yildirim I, Livermore D M
Department of Medical Microbiology, London Hospital Medical College.
J Med Microbiol. 1995 Oct;43(4):294-9. doi: 10.1099/00222615-43-4-294.
Two Salmonella typhimurium isolates were studied, one as a representative from a series of neonatal meningitis cases treated at an Istanbul teaching hospital, the other from a gastro-enteritis case seen at a different Istanbul hospital. Both isolates were resistant to extended-spectrum cephalosporins, as well as penicillins, aminoglycosides and chloramphenicol. Cephalosporin resistance depended on production of PER-1 beta-lactamase, which is an extended-spectrum class A enzyme that is only distantly related to TEM and SHV enzymes, and which was previously known only from Pseudomonas aeruginosa isolates. The PER-1 gene was carried by an 81-MDa plasmid, which also determined resistance to aminoglycosides and chloramphenicol. Although it was not self-transmissible to Escherichia coli, this element did transfer if mobilised with plasmid pUZ8. The two S. typhimurium isolates gave indistinguishable DNA restriction patterns and, in addition to their 81-MDa plasmid, also contained 52- and 2.8-MDa plasmids, the last of these encoded TEM-1 enzyme. The two isolates were identical in serotype, antibiogram and plasmid-profile but nevertheless differed in phage type, and, therefore, represented distinct strains. The emergence of cefotaxime and ceftriaxone resistance in salmonellae is disturbing, since these agents are preferred therapy for neonatal meningitis caused by members of the genus.
对两株鼠伤寒沙门氏菌分离株进行了研究，一株是伊斯坦布尔一家教学医院治疗的一系列新生儿脑膜炎病例中的代表性菌株，另一株来自伊斯坦布尔另一家医院的一例胃肠炎病例。两株分离株均对广谱头孢菌素、青霉素、氨基糖苷类和氯霉素耐药。头孢菌素耐药性取决于PER-1β-内酰胺酶的产生，PER-1是一种A类广谱酶，与TEM和SHV酶仅有远缘关系，此前仅在铜绿假单胞菌分离株中发现。PER-1基因由一个81-MDa质粒携带，该质粒还决定了对氨基糖苷类和氯霉素的耐药性。虽然它不能自行转移到大肠杆菌中，但如果用质粒pUZ8进行动员，该元件确实会转移。这两株鼠伤寒沙门氏菌分离株给出了难以区分的DNA限制性图谱，除了它们的81-MDa质粒外，还含有52-MDa和2.8-MDa质粒，其中最后一个编码TEM-1酶。这两株分离株在血清型、抗菌谱和质粒图谱方面相同，但在噬菌体类型上不同，因此代表不同的菌株。沙门氏菌对头孢噻肟和头孢曲松耐药性的出现令人不安，因为这些药物是该属成员引起的新生儿脑膜炎的首选治疗药物。
