Implementation of a Risk-Orientated Hygiene Analysis for the Control of Salmonella JAVA in the Broiler Production.

This field study aimed to establish a risk-orientated hygiene analysis on two broiler farms in Northwestern Germany for the practical use in broiler housing to evaluate the success of disinfection procedures for eradicating S. Java. The risk-orientated hygiene analysis enables fast, reproducible and cost-effective testing of broiler farms and in turn helps minimize the public health risk ensuing from S. Java. Farms were tested before and after cleaning as well as after disinfection according to a risk-orientated hygiene analysis for the presence of Salmonella DNA with qPCR. Positive PCR samples were confirmed by classical microbiology. Before cleaning, all checkpoints were tested positive for Salmonella DNA. Salmonella reduction of ca 66% of the sampled points could be achieved by intensive cleaning. A first disinfection on farm A and B failed to completely eradicate S. Java. A second disinfection followed and finally achieved a Salmonella-free status of the barns. During nine rearing periods, farms were tested weekly with boot swabs for Salmonella and at slaughter carcasses were tested for Salmonella status. No Salmonella were detected in these examinations. The two studied broiler farms have, to date, remained free of Salmonella.

Infection Dynamics and Antimicrobial Resistance Profile of Salmonella Paratyphi B d-tartrate Positive (Java) in a Persistently Infected Broiler Barn.

The infection dynamics of S. Java were examined in three consecutive rearing periods on a broiler farm in Northwestern Germany which had been persistently infected with S. Java for more than five years. The barn was investigated for Salmonella occurrence after cleaning and disinfection to verify the persistent contamination of the broiler house with S. Java before the start of the first rearing cycle. Confirmation of Salmonella absence in day-old chicks (time-point 1) as well as early establishment of infection between days 5-7 (time-point 2) were confirmed by caecal swabs prepared for qPCR and classical microbiological methods. At three time-periods (between days 11-15 (time-point 3), days 25-28 (time-point 4), and days 38-40 (time-point 5)) caecal content was examined for colony forming units (CFU) Salmonella/g. In general, there was an increase in Salmonella Java load at time-point 4 compared to time-points 3 and 5. Therefore, we observed a bell-shaped course of infection resulting in higher rates of Salmonella CFU/g prior to prethinning than at final slaughter. The antimicrobial susceptibility testing revealed resistance to tetracycline, fluorquinolones, trimethoprim, and cefoxitin.