CTX-M and tem as a predominant type of extended spectrum beta-lactamase among serratia marcescens isolated from solid organ recipients
A Młynarczyk, K Szymanek, A Sawicka-Grzelak, J Pazik, T Buczkowska, M Durlik, B Łągiewska, M Pacholczyk, A Chmura, L Pączek, G Młynarczyk
Ann Transplant 2009; 14(1): 71-71
Background: Serratia marcescens is an important pathogen in hospital infections, especially among patients with impaired immunity. Particularly dangerous are strains producing extended - spectrum beta - lactamases (ESBLs) and carbapenemases. The aim of the work was to establish the percentage of ESBL producing strains of S. marcescens isolated form patients of Transplantation Institute of Transplantology as well as the type of the enzyme.
Material/Methods: The standard clinical microbiology methods were applied to identification and assessment antibiotics susceptibility of S. marcescens isolated from patients of Institute of Transplantology in four years (2005-2008). All strains were examined for ESBL production by several phenotype methods. 28 strains were examined in PCR reaction with starters for most popular types of ESBLs: TEM, SHV, CTX-M.
Results: In total 386 S. marcescens strains from 257 patients were isolated from various specimens form patients from Transplantation Institute. In 2005, 88 patients were infected, and respectively in 2006, 82 patients, in 2007, 57 patients and in 2008, 30. In the case of 188 patients (73%), it was shown by phenotype methods that infecting strain produced ESBL. From 28 strains chosen for molecular analysis 17 produced both CTX-M and TEM beta-lacta-mase, 9 produced only TEM - type, and 2 strains only CTX-M type beta-lacta-mase. Two strains from 2008 were resistant to carbapenems.
Conclusions: In the 2008 the frequency of S. marcescens isolation diminished two times compared to the previous years. The CTX-M-type of ESBL predominated among beta-lactamases produced by the strains. Alarming is the appearance of S. marcescens strains resistant to carbapenems.