Lizi Yin

Bio: Lizi Yin is an academic researcher from Ghent University. The author has contributed to research in topics: Chlamydia psittaci & Psittacosis. The author has an hindex of 7, co-authored 13 publications receiving 138 citations. Previous affiliations of Lizi Yin include Sichuan Agricultural University.

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

Abstract: 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. Keywords: roe deer; serology; screening; antibodies; infection; pathogens; exposure; sentinel (Published: 24 November 2015) Citation: Infection Ecology and Epidemiology 2015, 5: 29862 - http://dx.doi.org/10.3402/iee.v5.29862

Pathogenicity of low and highly virulent Chlamydia psittaci isolates for specific-pathogen-free chickens.

Abstract: 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 a...

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

Abstract: 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.

Prevalence of Chlamydia abortus in Belgian ruminants

Abstract: Chlamydia (C.) abortus enzootic abortion still remains the most common cause of reproductive failure in sheep-breeding countries all over the world. Chlamydia abortus in cattle is predominantly associated with genital tract disease and mastitis. In this study, Belgian sheep (n=958), goats (n=48) and cattle (n=1849) were examined, using the ID Screen (TM) Chlamydia abortus indirect multi-species antibody ELISA. In the sheep, the highest prevalence rate was found in Limburg (4.05%). The animals of Antwerp, Brabant and Liege tested negative. The prevalence in the remaining five regions was low (0.24% to 2.74%). Of the nine goat herds, only one herd in Luxembourg was seropositive. In cattle, the highest prevalence rate was found in Walloon Brabant (4.23%). The animals of Limburg and Namur tested negative. The prevalence rate in the remaining seven regions ranged between 0.39% and 4.02%.

Tick-Borne Encephalitis Virus, United Kingdom

Abstract: During February 2018-January 2019, we conducted large-scale surveillance for the presence and prevalence of tick-borne encephalitis virus (TBEV) and louping ill virus (LIV) in sentinel animals and ticks in the United Kingdom. Serum was collected from 1,309 deer culled across England and Scotland. Overall, 4% of samples were ELISA-positive for the TBEV serocomplex. A focus in the Thetford Forest area had the highest proportion (47.7%) of seropositive samples. Ticks collected from culled deer within seropositive regions were tested for viral RNA; 5 of 2,041 ticks tested positive by LIV/TBEV real-time reverse transcription PCR, all from within the Thetford Forest area. From 1 tick, we identified a full-length genomic sequence of TBEV. Thus, using deer as sentinels revealed a potential TBEV focus in the United Kingdom. This detection of TBEV genomic sequence in UK ticks has important public health implications, especially for undiagnosed encephalitis.

Emerging Chlamydia psittaci infections in chickens and examination of transmission to humans

Abstract: Chlamydia psittaci and atypical Chlamydiaceae infections are (re)-emerging in chickens. We therefore examined the prevalence of C. psittaci, atypical Chlamydiaceae and their zoonotic transmission on 19 Belgian chicken farms. Atypical Chlamydiaceae were not detected in chickens but 18 out of 19 farms were positive for C. psittaci by culture and PCR. C. psittaci ompA genotypes A and D were discovered. None of the examined humans (n = 31) was infected with atypical Chlamydiaceae, but 29 (93.5%) of them were positive for C. psittaci by culture and PCR. Genotypes A, D and a mixed infection with genotypes C and D were found. Humans (n = 2) working at the C. psittaci-negative farm never had respiratory complaints, while 25 out of 29 positive farmers (86.2%) reported yearly medical complaints potentially related to psittacosis. Four of them currently experienced respiratory disease and one of them was being treated with antibiotics. Four farmers (12.5%) mentioned that they had pneumonia after starting to keep chickens. Occupational physicians should be aware of emerging Chlamydiaceae infections in chickens.

Outbreak of psittacosis in a group of women exposed to Chlamydia psittaci-infected chickens

Abstract: Eight cases of psittacosis due to Chlamydia psittaci were identified in May 2013 among 15 individuals involved in chicken gutting activities on a mixed poultry farm in France. All cases were women between 42 and 67 years-old. Cases were diagnosed by serology and PCR of respiratory samples. Appropriate treatment was immediately administered to the eight hospitalised individuals after exposure to birds had been discovered. In the chicken flocks, mainly C. gallinacea was detected, a new member of the family Chlamydiaceae, whereas the ducks were found to harbour predominantly C. psittaci, the classical agent of psittacosis. In addition, C. psittaci was found in the same flock as the chickens that the patients had slaughtered. Both human and C. psittaci-positive avian samples carried the same ompA genotype E/B of C. psittaci, which is widespread among French duck flocks. Repeated grassland rotations between duck and chicken flocks on the farm may explain the presence of C. psittaci in the chickens. Inspection by the veterinary service led to temporary closure of the farm. All birds had to be euthanised on site as no slaughterhouses accepted processing them. Farm buildings and grasslands were cleaned and/or disinfected before the introduction of new poultry birds.