Colonization of Gram negative MDRO among hospitalized patients

Infection Control and Hospital Epidemiology April 2010 Vol 31, No 3 pages 330-337 by
Amy Weintraub,MD
Mollie Roediger,MS
Melissa Barber, MLT
Amy Summers,BS
Ann M. Fieberg,MS
James Dunn, RN
Venus Seldon, RN
Fluryanne Leach,MS
Xio-Zhe Huang, PhDMikeljon P. Nikolich, PhD
Glenn Wortmann,MD

Natural History of Colonization with Gram Negative MDRO among Hospitalized Patients

This study was to determine the anatomical sites of colonization of gram negative MDROs
This study was done at Walter Reed Army Hospital with deployed patients.

Common infection is acinetobacter from Iraq

Groin was the best site for gnmdro
perirectal and groin areas were the best site for esbl e coli

A prolonged study showed that colonization persisted with gnbacteria.

Carbepenem use was censored in this study. Its use was associated with an increased rate of esbl e coli.

Spontaneous decolonization is rare.


Infection Control and Hospital Epidemiology April 2010 Vol 31 No 4 pages 338-340

Lisa Maragakis,MD, MPH
Trish Perl, MD, MSc.

Commentary: How can we stem the rising tide of Multi-resistant gram negatie bacilli?

There is evidence that gram negative bacilli are an emerging threat in healthcare institutions.
We have extensive knowledge of MRSA and VRE. We have less knowledge about gram negative resistant orgs.

The Healthcare Infection Control ADvisory Committee's Management of Multi-drug Resistant Organisms in Health Care Settings
by JD Seigel
E Rhinhart
M Jackson
L Chairello

Healthcare Infection Control Practices Advisory Committee. Management of Multi drug reistant organisms in healthcare settings. 2006 http://www.cdc.gov/ncidod/dhqp/pdf/ar/mdroGuideline2006.pdf accessed April 5, 2010


This article describes a 2 tier level of interventions to prevent and respond to transmission of MDRO in healthcare settings.
The 2nd tier included intensified surveillance culture to identify those patients who are colonized.

In the article by Weintraub et al they have described anatomical sites beneficial to get accurate culturing.Colonizers tended to last about 2 months or longer with gram neg resistant bacilli.

large groups of patients are not identified by the use of clinical cultures, only by the use of surveillance cultures. These unidentified colonized patients provide a resevoir for potentially transmission to other patients.

Weintraub et al have described certain sites for gran neg bacilli, and there are other identified culture sites for MRSA and VRE. To do all these surveillance cutlures on each patient would put a big burden on the microbiology lab.

But miltary setting aside, Weintraub et al have shown that the hospital is the primary setting for MDRo transmission. Selected pateint groups should be cultured: those who havebeen recently hospitalized and specific populations such as military returning from deployment.

More data is needed before we plunge into large scale surveillance , which could direct resources from other important infection prevention practices.