Outbreak Caused by Enterobacteriaceae Harboring NDM-1 Metallo-β-Lactamase Carried in an IncFII Plasmid in a Tertiary Care Hospital in Mexico City

Abstract

Carbapenem-resistant Enterobacteriaceae carrying New Delhi metallo-␤-lactamase 1 (NDM-1) have rarely been reported in Latin America. We report of an outbreak caused by a bla NDM-1 -harboring plasmid spread through different bacterial species, including Escherichia coli (ST617) and Enterobacter cloacae (ST182) isolates from the same patient and three Klebsiella pneumoniae isolates (ST22) derived from three epidemiologically related patients. IncFII plasmids were found in all strains. Measures to control the outbreak were applied successfully. The spread of carbapenem-resistant Enterobacteriaceae (CRE) is a global concern. The most common mechanism of CRE is the acquisition of plasmid-borne ␤-lactamases that can hydrolyze carbapenems. The New Delhi metallo-␤-lactamase (MBL) 1 (NDM-1) has been reported in several regions of the world, mostly in patients with a history of travel to areas where it is endemic but scarcely in Latin America (1-4). We report an outbreak caused by NDM-1-harboring Enterobacteriaceae, where horizontal gene transfer likely occurred between different species with further clonal expansion.Hospital setting and bacterial strains. Ours is a 230-bed tertiary care hospital in Mexico City with a 14-bed intensive care unit (ICU) to which adult patients from the all of Mexico are referred for medical treatment. The first case of CRE carrying an MBL was detected on 5 November 2013 in a patient transferred from a southwestern city in Mexico who was admitted to the ICU. A second case was identified on 14 December 2013 in the ICU. After this, we established active screening of CRE carriers via rectal swab cultures. Rectal swabs were cultured using a 10-g ertapenem disk in 5 ml Trypticase soy broth (6). Other clinical samples were collected from the patients according to the usual protocol.Antimicrobial susceptibility tests and molecular detection of ␤-lactamases. Identification and antimicrobial susceptibility of the isolates were done with the Vitek 2 (bioMérieux, Durham, NC) and interpreted according to CLSI standards (7). Additionally, the EDTA double-disc synergy phenotypic test was performed to detect metallo-␤-lactamases (8). Presence of ␤-lactamases was determined by PCR (bla IMI , bla VIM , bla NDM , bla GES bla CTX-M-15 , bla , bla SHV , bla TEM ), as described elsewhere (8, 9). PCR-generated fragments were purified by Qiaquick PCR purification spin columns (Qiagen, Venlo, Netherlands), and sequenced with a 3130xl genetic analyzer (AB Applied Biosystems, Hitachi, San Francisco, CA). The nucleotide sequences were analyzed through the National Center for Biotechnology Information website (http://www.ncbi.nlm.nih.gov). Five isolates (1 Escherichia coli, 1 Enterobacter cloacae, and 3 Klebsiella pneumoniae) from four patients were evaluated. All isolates showing resistance to third-generation cephalosporins, quinolones, monobactams, carbapenems, and PCR were positive for NDM-1 and CTX-M-15 (Table 1).Genotyping. Pulsed-field gel electrophoresis (PFGE) was performed for all K. pneumoniae clinical (n ϭ ...

Molecular and microbiological report of a hospital outbreak of NDM-1-carrying Enterobacteriaceae in Mexico

“…The combination of clonal expansion and horizontal gene transfer demonstrated in this study has been described in Mexico, UK, and Chennai, India [6,41]. In contrast, isolates from Haryana, India, showed an apparent clonal expansion by the demonstration of two types of predominant plasmids [41].…”

Fosfomycin trometamol in the prophylaxis of post‐kidney transplant urinary tract infection: A controlled, randomized clinical trial

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