Imipenem-resistance in Serratia marcescens is mediated by plasmid expression of KPC-2
Authors: N-M Deng
W-Q Su
Y-Q Zhu
L Li
Journal: European review for medical and pharmacological sciences (2017)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Imipenem; Serratia marcescens; KPC-2; antibiotic resistance; plasmid-mediated
Affiliations: Department of Laboratory, Qingdao Municipal Hospital, Qingdao, China. .

Abstract:  Objective: Imipenem is a broad-spectrum carbapenem antibiotic with applications against severe bacterial infections. Here, we describe the identification of imipenem-resistant Serratia marcescens in our hospital and the role of plasmid-mediated KPC-2 expression in imipenem resistance. Materials and methods: We used the modified Hodge test to detect carbapenemase produced in imipenem-resistant strains. Results: His resistance can be transferred to E. coli in co-culture tests, which implicates the plasmid in imipenem resistance. PCR amplification from the plasmid identified two products consistent with KPC-2 of 583 and 1050 bp that were also present in E. coli after co-culture. The restriction pattern for both plasmids was identical, supporting the transfer from the S. marcescens isolate to E. coli. Finally, gene sequencing confirmed KPC-2 in the plasmid. Conclusions: Due to the presence of KPC-2 in the imipenem-resistant S. marcescens, we propose that KPC-2 mediates antibiotic resistance in the S. marcescens isolate. 

Retracted: No

PubPeer comments:
 Additional problematic data figure 3b J Mol Med (Berl). 2006 Jul;84(7):551-60. ![file] , 
 Thank you for this remark. In reply to comments to a few other old papers I did not argue because the original data were no longer available for evaluation. However, in this case the comment of Pandanus Comatus about 18S RNA seems inappropriate because it regards two independent papers with no authors in common. I cannot see how the original image could have been duplicated. This casts some doubts about the accuracy of software-based image comparisons. Regarding the FtH and FtL bands, unfortunately almost 15 years after publication the original data are not available. However, it can be appreciated that the blot has not been reused by observing the last two lanes (7 and 8 from the left): the signals are stronger than those of lanes 5 and 6 for FtH and weaker for FtL. Moreover, it should be noted that ferritin (Ft) is composed of H and L subunits, which are coordinately regulated. No wonder that the figure shows a similar pattern for FtH and FtL. , 
  However, in this case the comment of Pandanus Comatus about 18S RNA seems inappropriate because it regards two independent papers with no authors in common. I cannot see how the original image could have been duplicated.  Both papers from Institute of General Pathology, University of Milan,Via Luigi Mangiagalli 31, 20133 Milan, Italy. 1. Carcinogenesis. 2004 Nov;25(11):2089-100. Epub 2004 Jul 7. Hepatocyte growth factor-activated NF-kappaB regulates HIF-1 activity and ODC expression, implicated in survival, differently in different carcinoma cell lines. Tacchini L1, De Ponti C, Matteucci E, Follis R, Desiderio MA. Author information 1 Institute of General Pathology, University of Milan, Via Luigi Mangiagalli 31, 20133 Milan, Italy. 2. J Mol Med (Berl). 2006 Jul;84(7):551-60. Epub 2006 Jun 13. IRP1-independent alterations of cardiac iron metabolism in doxorubicin-treated mice. Corna G1, Galy B, Hentze MW, Cairo G. Author information 1 Institute of General Pathology, University of Milan, Via Mangiagalli 31, Milan 20133, Italy. , 
 #2  Moreover, it should be noted that ferritin (Ft) is composed of H and L subunits, which are coordinately regulated. No wonder that the figure shows a similar pattern for FtH and FtL. But shifted over by one lane. , 
 Fig 3a, here compared with *[right]* Fig 2B from Tacchini et al (2004). ![file] ,