High Gastrointestinal Colonization Rate with IMP-producing E. coli in a Neonatal Intensive Care Unit.

ELENA ALAN; MAGARIÑOS FRANCISCO; JEWTUCHOWICZ V; FACENTE A; GUTKIND GABRIEL; DI CONZA JOSÉ; RADICE MARCELA

New Orleans

Congreso; ASM MICROBE 2017; 2017

American Society for Microbiology

The emergence and spread of carbapenemase-producing bacteria are a major concern of public health systems worldwide. Different types of enzymes, including KPC, VIM, IMP, NDM, and OXA-48, have been involved in this resistant phenotype. Among these markers, IMP type enzymes have been recurrently identified in Pseudomonas spp., however they are seldom recognized in Enterobacteriaceae. Hospitalized patients, mainly immunocompromised or neonates, are at high risk of acquiring these pathogens. The aim of this study was to characterize carbapenem-resistant Enterobacteriaceae (CRE) recovered from rectal colonization of newborns housed at the neonatal ICU.Active surveillance cultures (ASC) are routinely conducted on patients admitted to Intensive Care Unit (ICU) in our hospital. During November ? December 2016, 11 carbapenem-resistant Escherichia coli (CREc) were detected using CHROMagar KPC. Antibiotic susceptibility was assessed by Vitek 2 system. Phenotypic screening of carbapenemases was performed using imipenem and phenylboronic acid (300 µg) or EDTA (1µmol) containing disks. Identification of metallo-carbapenemases and MCR-1 coding genes were conducted by PCR amplification using specific primers, and sequencing. Genotypic characterization of CREc was performed by Rep-PCR and phylogenetic groups were determined according Clermont et al., 2005.All the isolates were resistant to beta-lactams, including both imipenem and meropenem (MIC≥16 ug/ml), amikacin, gentamicin and trimethoprim-sulfamethoxazole. One of them also displayed colistin resistance. The isolates rendered positive synergy with EDTA and it was further confirmed the presence of blaIMP in all of them. The isolates corresponded to phylogenetic group D, being categorized as extraintestinal pathogens. Finally, 9/11 were indistinguishable by PCR typing methods, displaying a rapid and high colonization rate. The colistin resistant isolate was also positive for mcr-1 and exhibited a different banding pattern. In this study we report the gastrointestinal carriage of IMP-type producing enterobacteria. The ASC in CHROMagar KPC warn about the presence of this infrequent resistant phenotype. Digestive tract colonization by CRE is a critical step before the development of nosocomial infections such as bloodstream, urinary tract and ventilator-associated infections in neonates. They can also play a key role in the spread of antibiotic resistance. Therefore, early and accurate detection of colonized patients will help reduce the spread of such organisms.