Antibiotic-Resistant Gram Negative Bacilli in Meals Delivered at a General Hospital, Italy

Maria Rosa Anna Plano,Anna Maria Di Noto,Caterina Mammina,Sonia Sciortino,Alberto Firenze

doi:10.1155/2009/476150

Abstract

This study aimed at detecting the presence of antibiotic-resistant Gram-negatives in samples of meals delivered at the University General Hospital of Palermo, Italy. Antibiotic resistant Gram negatives were isolated in July—September 2007 ffrom cold dishes and food contact surfaces and utensils. Bacterial strains were submitted to susceptibility test and subtyped by random amplification of polymorphic DNA (RAPD). Forty-six of 55 (83.6%) food samples and 14 of 17 (82.3%) environmental swabs were culture positive for Gram negative bacilli resistant to at least one group of antibacterial drugs. A total of 134 antibiotic resistant strains, 51 fermenters and 83 non-fermenters, were recovered. Fermenters and non-fermenters showed frequencies as high as 97.8% of resistance to two or more groups of antibiotics and non fermenters were 28.9% resistant to more than three groups. Molecular typing detected 34 different profiles among the fermenters and 68 among the non-fermenters. Antibiotic resistance was very common among both fermenters and non-fermenters. However, the wide heterogeneity of RAPD patterns seems to support a prominent role of cross-contamination rather than a clonal expansion of a few resistant isolates. A contribution of commensal Gram negatives colonizing foods to a common bacterial resistance pool should not been overlooked.

Highlights

Resistance to various antibacterial drugs is rapidly emerging and posing a major challenge to Public Health
This study aimed at detecting the presence of multidrug resistant Gram-negatives (MDR-GN) in food samples delivered through a plated service at the University general hospital “Azienda Ospedaliero-Universitaria Policlinico” (AOUP), Palermo, Italy
To contribute additional information about foodmediated exposure to Gram negative antimicrobial resistant bacterial (ARB), we investigated the occurrence of these organisms in food products processed in a catering premise and delivered to hospitalized patients

Summary

Introduction

Resistance to various antibacterial drugs is rapidly emerging and posing a major challenge to Public Health. While occurrence and evolution of a foodborne resistant pathogen’s incursion into various community and healthcare associated settings has been frequently experienced and thoroughly studied, horizontal gene transfer events taking place between commensals and pathogens and between food-derived commensals and human commensals are to date poorly known [4,5,6,7,8,9,10,11] Such transfers will likely be most successful when the host is simultaneously submitted to a selective pressure by an antimicrobial substance to which the involved organisms are resistant [1]. From this point of view, health-care associated settings are the environments where ARB and their resistance determinants are most likely to be present, a genetic horizontal transmission has more chances to occur, and the consequences in terms of therapeutic failures and costs might be more severe [1, 12, 13]

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