Exacerbation ofChlamydophila psittacipathogenicity in turkeys superinfected byEscherichia coli

Abstract

-Both Chlamydophila psittaci and Escherichia coli infections are highly prevalent in Belgian turkeys and therefore they both might contribute to the respiratory disease complex observed in turkeys. C. psittaci can infect turkeys within the first week of age, even in the presence of maternal antibodies. However, the first C. psittaci outbreaks occur mostly at the age of 3 to 6 weeks, the period when also E. coli infections appear on the farms. Therefore, we examined in this study the pathogenicity of an E. coli superinfection on C. psittaci predisposed turkeys. Turkeys were infected with C. psittaci, E. coli or with C. psittaci followed by E. coli. Simulating the impact of an E. coli infection during the acute phase or the latent phase of a C. psittaci infection, turkeys received E. coli at 1 or 5 weeks post C. psittaci infection, respectively. E. coli superinfection during the acute phase of C. psittaci infection increased C. psittaci excretion and stimulated chlamydial replication in the respiratory tract resulting in exacerbated clinical disease. Interestingly, E. coli superinfection during the latent phase of C. psittaci infection induced chlamydial replication, leading to increased C. psittaci-specific antibody titres. In addition, chlamydial predisposition gave higher E. coli excretion compared with turkeys that had only been infected with E. coli. Overall, the present study clearly demonstrates the pathogenic interplay between C. psittaci and E. coli resulting in more severe respiratory disease. Chlamydophila psittaci / Escherichia coli / turkeys

Assessment of Chlamydia psittaci Shedding and Environmental Contamination as Potential Sources of Worker Exposure throughout the Mule Duck Breeding Process

“…It is probable that some interventions may induce more stress for birds and lead to heavier shedding, but this cannot explain all the differences in the prevalence or the excretion level in birds and other factors, such as the "outdoor" factor, that seem to critically impact shedding ( Table 1). As has been previously reported, the presence of coinfections could exacerbate chlamydial shedding (27)(28)(29)(30). Unlike the cases described in these latter studies, it is interesting that the herpesvirus infection that emerged in flock A2 (resulting in premature slaughtering) did not increase the level of C. psittaci shedding from ducks, which therefore had the same shedding pattern as those of flock A1.…”

Effect of ovotransferrin and lactoferrins onChlamydophila psittaciadhesion and invasion in HD11 chicken macrophages

“…The outcome of the infection at 48 h p.i. was analyzed by immunofluorescence staining using a scoring system from 0 to 5 as previously described [34].…”

A severe case of pneumopathy in a duck breeder due to Chlamydia psittaci diagnosed by 16S rDNA sequencing

“…Most of the time, C. psittaci infections in ducks are asymptomatic. Co-infections with another bacteria or viruses have already been reported in turkey flocks, where they exacerbated the chlamydial shedding in infected birds (Van Loock et al, 2006;Loock et al, 2006). It is possible that such co-infections also occurred in the patient's flocks, leading to an increase in C. psittaci shedding.…”