Lizi Yin

Emerging Chlamydia psittaci infections in the chicken industry and pathology of Chlamydia psittaci genotype B and D strains in specific pathogen free chickens

Sera of 30 Belgian and 10 Northern French chicken farms were tested by a Chlamydia (C.) psittaci major outer membrane protein (MOMP) based ELISA. Ninety-six percent, 93% and 90% of the Belgian broilers, broiler breeders and layers were seropositive. Ninety-one percent of the French broilers were seropositive. In addition, tissues of 5 Belgian and 5 French broiler farms were examined at slaughter. All French farms were culture positive while C. psittaci was cultured from the lungs of 80% of examined Belgian farms. C. psittaci infections are apparently emerging in chickens raised in Belgium and Northern France. We could proof Hill-Evans postulates for chicken-derived C. psittaci genotype B and D strains. Chicken-processing plant employees should be considered a risk group for human psittacosis. There is a need for higher awareness and for efficient risk assessment and management of C. psittaci infections in chickens as chlamydiosis in broilers seems to be underdiagnosed and infections with highly virulent strains do occur.

Serologic screening for 13 infectious agents in roe deer ( Capreolus capreolus ) in Flanders

Introduction In order to investigate the role of roe deer in the maintenance and transmission of infectious animal and human diseases in Flanders, we conducted a serologic screening in 12 hunting areas. Materials and methods Roe deer sera collected between 2008 and 2013 (n=190) were examined for antibodies against 13 infectious agents, using indirect enzyme-linked immunosorbent assay, virus neutralisation, immunofluorescence, or microagglutination test, depending on the agent. Results and discussion High numbers of seropositives were found for Anaplasma phagocytophilum (45.8%), Toxoplasma gondii (43.2%) and Schmallenberg virus (27.9%), the latter with a distinct temporal distribution pattern following the outbreak in domestic ruminants. Lower antibody prevalence was found for Chlamydia abortus (6.7%), tick-borne encephalitis virus (5.1%), Neospora caninum (4.8%), and Mycobacterium avium subsp paratuberculosis (4.1%). The lowest prevalences were found for Leptospira (1.7%), bovine viral diarrhoea virus 1 (1.3%), and Coxiella burnetii (1.2%). No antibodies were found against Brucella sp., bovine herpesvirus 1, and bluetongue virus. A significant difference in seroprevalence between ages (higher in adults >1 year) was found for N. caninum. Four doubtful reacting sera accounted for a significant difference in seroprevalence between sexes for C. abortus (higher in females). Conclusions Despite the more intensive landscape use in Flanders, the results are consistent with other European studies. Apart from maintaining C. abortus and MAP, roe deer do not seem to play an important role in the epidemiology of the examined zoonotic and domestic animal pathogens. Nevertheless, their meaning as sentinels should not be neglected in the absence of other wild cervid species.

Pathogenicity of Low and Highly Virulent Chlamydia psittaci Isolates for Specific-Pathogen-Free Chickens

SUMMARY In commercially raised poultry, chlamydiosis mostly seems to occur on turkey or duck farms, sometimes associated with zoonotic transmission and disease (psittacosis) in humans. However, Chlamydia infections are apparently emerging in chickens, and information on the virulence of Chlamydia in chickens is limited. Up-to-date Chlamydia psittaci genotypes B and D are most frequently found in broilers. We examined the pathogenicity of the well-characterized C. psittaci genotype B (CP3) and D (92/1293) strains in experimentally (aerosol) infected specific-pathogen-free chickens. Both strains caused conjunctivitis, rhinitis, and dyspnea. Pharyngeal and cloacal C. psittaci excretion was observed in all infected animals, indicative for systemic dissemination as proven by immunofluorescence staining of frozen tissue sections. Histopathologic lesions were present in all infected chickens. However, differences in pathology were observed. Genotype D led to mortality and more severe clinical signs and lesions as compared to genotype B, which showed lower virulence. RESUMEN Patogenicidad de aislamientos baja y alta virulencia de Chlamydia psittaci para aves libres de patógenos específicos. La clamidiosis puede presentarse en aves criadas comercialmente, principalmente en granjas de pavos y patos, a veces asociados con la transmisión zoonótica y la presentación de la enfermedad (psitacosis) en humanos. Sin embargo, las infecciones por Chlamydia aparentemente están surgiendo en los pollos y la información sobre la virulencia de Chlamydia en los pollos es limitada. Hasta la fecha, los genotipos B y D de Chlamydia psittaci son los más frecuentes en pollos de engorde. Se examinó la patogenicidad de las cepas bien caracterizadas de C. psittaci genotipo B (CP3) y genotipo D (92/1293) en aves libres de patógenos específicos infectados experimentalmente por aerosol. Ambas cepas causaron conjuntivitis, rinitis, y disnea. Se observó excreción faríngea y cloacal de C. psittaci en todos los animales infectados, indicativas de diseminación sistémica como fue demostrado por la tinción de inmunofluorescencia de cortes de tejido congelados. Las lesiones histopatológicas estaban presentes en todos los pollos infectados. Sin embargo, se observaron diferencias en la patología. El genotipo D ocasionó mortalidad además de signos clínicos y lesiones más graves en comparación con el genotipo B, que mostró una menor virulencia.

Host-pathogen interactions in specific pathogen-free chickens following aerogenous infection with Chlamydia psittaci and Chlamydia abortus

Although Chlamydia (C.) psittaci infections are recognized as an important factor causing economic losses and impairing animal welfare in poultry production, the specific mechanisms leading to severe clinical outcomes are poorly understood. In the present study, we comparatively investigated pathology and host immune response, as well as systemic dissemination and expression of essential chlamydial genes in the course of experimental aerogeneous infection with C. psittaci and the closely related C. abortus, respectively, in specific pathogen-free chicks. Clinical signs appeared sooner and were more severe in the C. psittaci-infected group. Compared to C. abortus infection, more intense systemic dissemination of C. psittaci correlated with higher and faster infiltration of immune cells, as well as more macroscopic lesions and epithelial pathology, such as hyperplasia and erosion. In thoracic air sac tissue, mRNA expression of immunologically relevant factors, such as IFN-γ, IL-1β, IL-6, IL-17, IL-22, LITAF and iNOS was significantly stronger up-regulated in C. psittaci- than in C. abortus-infected birds between 3 and 14 days post-infection. Likewise, transcription rates of the chlamydial genes groEL, cpaf and ftsW were consistently higher in C. psittaci during the acute phase. These findings illustrate that the stronger replication of C. psittaci in its natural host also evoked a more intense immune response than in the case of C. abortus infection.

The immune response against Chlamydia suis genital tract infection partially protects against re-infection

The aim of the present study was to reveal the characteristic features of genital Chlamydia suis infection and re-infection in female pigs by studying the immune response, pathological changes, replication of chlamydial bacteria in the genital tract and excretion of viable bacteria. Pigs were intravaginally infected and re-infected with C. suis strain S45, the type strain of this species. We demonstrated that S45 is pathogenic for the female urogenital tract. Chlamydia replication occurred throughout the urogenital tract, causing inflammation and pathology. Furthermore, genital infection elicited both cellular and humoral immune responses. Compared to the primo-infection of pigs with C. suis, re-infection was characterized by less severe macroscopic lesions and less chlamydial elementary bodies and inclusions in the urogenital tract. This indicates the development of a certain level of protection following the initial infection. Protective immunity against re-infection coincided with higher Chlamydia-specific IgG and IgA antibody titers in sera and vaginal secretions, higher proliferative responses of peripheral blood mononuclear cells (PBMC), higher percentages of blood B lymphocytes, monocytes and CD8+ T cells and upregulated production of IFN-γ and IL-10 by PBMC.

Chlamydia psittaci infections in Chinese poultry: a literature review

Chlamydia (C.) psittaci, formerly known as Chlamydophila psittaci infections cause important economical losses to the poultry industry and are a danger to public health. The economic and zoonotic impact of C. psittaci infections in the Western poultry industry is well documented. Less is known on its occurrence in Asia. In the following review we address C. psittaci infections in Chinese poultry in view of China supplying 40.8% of global egg production and 14.2, 69.3 and 91.1% of global chicken, duck and goose meat, respectively. The current paper compiles English and Chinese scientific literature on C. psittaci infections in Chinese poultry. The paper is focusing on seroprevalence, culture, direct antigen detection, molecular characterisation, observed symptoms, Chinese traditional medicine and psittacosis case reports. A review on the epidemiology of chlamydiosis in Chinese poultry clearly illustrates the widespread presence of virulent C. psittaci strains in chickens, ducks and geese across China. In Western countries, C. psittaci infections in poultry are principally treated with antibiotics. In China, however, herbal medicine is often used in conjunction with antibiotic treatment or as prophylaxis. The applied production and marketing systems facilitate zoonotic transfer. Chinese occupationally acquired psittacosis cases include reports on infections contracted from ducks, pigeons, chickens and peacocks.

Chlamydia Psittaci Strains from Broiler Chickens Induce Histopathological Lesions and Mortality in SPF Chickens

Abstract A detailed study on histopathological lesions induced by two C. psittaci outer membrane protein A (ompA) genotype B strains (10/423 and 10/525) and one genotype D strain (10/298) in experimentally infected (aerosol) specific pathogen free (SPF) chickens was performed. The strains were derived from Belgian and French commercially raised broilers with pneumonia. Both genotype B and D strains induced conjunctivitis, rhinitis, sinusitis, tracheitis, bronchitis, pneumonitis, airsacculitis, splenitis, hepatitis, nephritis, and enteritis in sequentially (days 2 to 34 post infection) euthanized chickens. Inflammation of the ovaries was only observed in genotype D infected chickens. Overall, the genotype D strain caused more severe gross and histopathological lesions and mortality (54.5%) early upon infection. The genotype D strain seemed to replicate faster as severity of the lesions increased more quickly. C. psittaci is a primary pathogen in chickens, and efficient monitoring and control of this emerging zoonotic pathogen is urgently needed.