By hiding inside macrophages (a type of white blood cell in blood and tissue which is the first line of defence against microbes) Enterobacter lies dormant and does not stimulate any inflammatory responses, allowing it to escape the action of the few antibiotics that remain available for treating the infection. 

Enterobacter infections, including wound infections, urinary tract infections, gastroenteritis, meningitis, pneumonia and septicemia, are serious infections with a high mortality rate, even with appropriate treatment.  

This breakthrough could help to develop new ways to treat infected patients and clear Enterobacter infections more efficiently, leading to less deaths. 

The study has been published in the Journal of Infectious Diseases. 

This research was carried out at the Infection Biology Group of the Wellcome-Wolfson Institute for Experimental Medicine at Queen’s University Belfast by the Valvano Lab Research Team including Dr Georgiana Parau, Ms. Hannah Parks, Ms. Amy Anderson and Dr Inmaculada Garcia-Romero. 

Lead researcher on the study, Professor Miguel A. Valvano, Chair in Microbiology and Infectious Diseases from the Wellcome-Wolfson Institute for Experimental Medicine at Queen’s University Belfast, explains: “Despite extensive information on antibiotic resistance by Enterobacter species, very little is known about how these bacteria cause infection. Our new study has bridged this knowledge gap by showing for the first time that antibiotic-resistant isolates of Enterobacter species can survive inside human macrophages without being killed.  

“The demonstration that Enterobacter isolates can hide inside macrophages has important clinical implications for the treatment of infected patients since antibiotics cannot reach the intracellular bacteria and the macrophages cannot easily remove them.” 

The research was funded by the Biotechnology and Biological Sciences Research Council. 

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