Monitoring Antibiotic Resistance in Campylobacter jejuni from Italy in the last 10 years (2011-2021)

Abstract T3

Presenter: Agustin Conesa (European Food Safety Authority)

Campylobacter jejuni is considered the main pathogen in human foodborne outbreaks worldwide. Over the past years, several studies have reported antibiotic-resistant (AMR) in C. jejuni strains. In Europe, the official monitoring of AMR comprises the testing of Campylobacter spp. from food-producing animals because is responsible for human infections and usually predominant in poultry. While food-producing animals are considered to be a major source of campylobacteriosis through contamination of food products. Concerns are growing due to the current classification of C. jejuni by the WHO as a “high priority pathogen” due to the emergence of resistance to multiple drugs such as those belonging to the fluoroquinolones, macrolides, and other classes, which limits the treatment alternatives. This study is aimed to assess the AMR of C. jejuni isolated from humans, poultry, and birds from wild and urban Italian habitats to identify correlations between phenotypic AMR comparing the origin of the isolates, given the public health concern represented by resistant pathogens in food-producing animals and the paucity of data about this topic in Italy. To achieve this 2,734 C. jejuni strains isolated from domestics and wild animals and humans, during the period 2011-2021 were analyzed. The resistance phenotypes of the isolates were determined using the microdilution method with EUCAST breakpoints, for the following antibiotics: Nalidixic acid, ciprofloxacin, chloramphenicol, erythromycin, gentamicin, streptomycin, tetracycline. The proportion of completely susceptible strains was very similar in isolates from humans and domestic animals (67,63% and 61,55% respectively) while strains from the wild animal population found a significantly higher prevalence (95,49%). Most of these strains were collected from domestic animals (95,01%) largely poultry samples (81,21%), that showed high level of resistances to nalidixic acid, ciprofloxacin, and tetracycline (67,39%, 67,27%, and 55,63% respectively). The human isolates reproduced the same patterns reinforcing the direct association between the increase in the resistance profiles over time with veterinary practices in the control of pathogens in birds. Fluoroquinolones had very high rates of resistant profiles since the 2011 with a stable trend over the last decade. Conversely erythromycin, showed a slight increase of resistance levels mostly for poultry and swine, while for wild animals and human strains had stable trends. Antibiotics released in animal production environments can interfere with the development of resistance profiles. A better knowledge of the resistance levels of C. jejuni is necessary, and mandatory monitoring of Campylobacter species in the different animal productions is suggested according to EFSA.

About the presenter

Veterinarian, MsD in public health, Ph.D. in biological sciences, EFSA fellow in the EU-FORA program at IZSAM G.Caporale, Teramo, IT

linkedin.com/in/agustin-conesa-9b9807130

Presenting in Speaking session 3 - Epidemiology and public health