Psittaci Research Articles

Clinical characteristics analysis of patients with pneumonia infected by Chlamydia psittaci

To explore the clinical characteristics of pneumonia infected by Chlamydophila psittaci (C. psittaci). A retrospective analysis was performed on 3 cases of C. psittaci pneumonia admitted to People's Hospital of Tongling City from July 2019 to January 2020. The patients' contact history, clinical manifestations, laboratory examination, imaging characteristics and evolution, etiology, treatment process and outcome were analyzed, so as to provide experience for the diagnosis and prevention of C. psittaci pneumonia. The 3 patients had been infected through pet or zoonotic exposures. All symptoms included high fever (body temperature > 39 centigrade), cough, sputum, chest tightness and dyspnea. The disease progressed rapidly, with severe acute respiratory distress syndrome (ARDS) and shock as the main manifestations, but the damages to the heart, liver and kidney were mild. Laboratory tests showed that C-reactive protein (CRP, all > 200 mg/L) and neutrophil proportion (Neut%, > 0.90) were significantly increased, while white blood cell count (WBC) and procalcitonin (PCT) were not significantly increased. Chest computed tomography (CT) showed inflammatory infiltration with interstitial changes, either unilateral or bilateral. Chest X-ray showed large areas of inflammatory infiltrations, fan-shaped or wedge-shaped to the edge of pleura. After 7 days of treatment, the bedside computed X-ray (CR) showed absorption of infiltration. After 11-13 days, the CT reexamination indicated lung infection was basically absorbed. Metagenomic next-generation sequencing (mNGS) confirmed the presence of C. psittaci in patients' sputum. It was sensitive to quinolones and tetracyclines. The patients' body temperature dropped to normal after 2-3 days of antibiotics, and all patients were extubated and transferred to normal ward 10 days later. The total course of illness was 20-30 days. The patients with C. psittaci pneumonia are critically ill, and clinical manifestations of moderate to severe ARDS and shock are common. Early diagnosis depends on mNGS, and reasonable treatment is important for prognosis.

Mycobacterieel conjunctivaal granuloom bij een Chinese zaagbekeend (Mergus squamatus)

Een vijf jaar oude, vrouwelijke Chinese zaagbekeend werd aangeboden met een chronische en wederkerende conjunctivitis van het linkeroog. Op klinisch onderzoek werden overvloedige traanvloei en een kazig nodulair letsel vastgesteld ter hoogte van de palpebrale conjunctiva. Bij autopsie werd een kazig, necrotisch beleg waargenomen ter hoogte van de linkerconjunctiva en de infraorbitale sinus, en er waren multipele granulomen in diverse interne organen aanwezig. Histologisch onderzoek toonde granulomateuze splenitis, hepatitis, arteritis, fibrinonecrotiserende enteritis, conjunctivitis en tevens amyloïdose van lever en milt aan. Bacteriologisch en moleculair onderzoek van de conjunctiva bij het levende dier toonde respectievelijk de aanwezigheid van een multiresistente Escherichia coli en Chlamydia psittaci aan. Deze bacteriën bleken van ondergeschikt pathogeen belang. Pre mortem werd echter geen cytologisch onderzoek of ziehlneelsen (ZN)-kleuring op de histologische coupe van het conjunctivabiopt uitgevoerd. Bovendien werden pre mortem geen bijkomende onderzoeken, zoals bloedonderzoek en radiografie, uitgevoerd. De definitieve diagnose van een Mycobacterium avium-infectie ter hoogte van de conjunctiva en de inwendige organen werd pas bevestigd na autopsie door middel van een ZNkleuring en polymerasekettingreactie (PCR)- analyse. Lokale en systemische behandelingen met antimicrobiële producten, zoals fluoroquinolonen, tetracyclinen en aminoglycosiden, waren niet succesvol.

Inhibitory effects of the Chlamydiaphage phiCPG1 capsid protein Vp1 on Chlamydia psittaci strain guinea pig inclusion conjunctivitis and Chlamydia trachomatis serovar E

Objective To evaluate inhibitory effects of the Chlamydiaphage phiCPG1 capsid protein Vp1 on Chlamydia psittaci strain guinea pig inclusion conjunctivitis (GPIC)and Chlamydia trachomatis (Ct)serovar E, and to provide new ideas for the treatment of Ct infection. Methods The Chlamydiaphage phiCPG1 capsid protein Vp1 was expressed in Escherichia coli BL21 transfected with the recombinant plasmid Vp1-pET30a (+), identified by Western blot analysis and purified by using dialysis bags. Bicinchonininc acid (BCA)assay was performed to determine the concentration of Vp1 protein. GPIC and Ct serovar E strains were both classified into 4 groups to be firstly incubated with Vp1 protein (Vp1 group), Tris-glycine solution (Tris group), S protein (S group)or Dulbecco's Modified Eagle Medium (DMEM, DMEM group)at room temperature for 3 hours, then were used to infect Hela cells followed by 72-hour (GPIC) or 48-hour (Ct serovar E)culture with the presence of Vp1 protein (Vp1 group), Tris-glycine solution (Tris group), S protein (S group)or DMEM (DMEM group). Subsequently, immunofluorescence staining was conducted to observe and count chlamydial inclusions. Results The number of GPIC inclusions was significantly different between the 4 groups after 72-hour culture (F= 476.632, P 0.05). Compared with the DMEM group, the Vp1 group showed a significant decrease of 80.2%±3.99% and 77.2%±1.79% in the number of GPIC and Ct serovar E inclusions respectively, with no significant difference in the inhibitory effect of Vp1 on GPIC versus Ct serovar E (t = 2.057, P > 0.05). Conclusion The phiCPG1 capsid protein Vp1 can obviously inhibit GPIC and Ct serovar E infections to a similar degree. Key words: Chlamydia trachomatis; Chlamydia muridarum; Capsid proteins; Phages; Protein Vp1

Immunogenicity analysis of a recombinant protein CPSIT_p7 and its expression in HeLa cells during persistent Chlamydophila psittaci infection

Objective To construct a prokaryotic expression plasmid for CPSIT_p7 gene from Chlamydophila psittaci （ Cps） 6BC strain and to evaluate immunogenicity of the recombinant protein His-CPSIT_p7 and detect its dynamic expression at mRNA and protein levels in HeLa cells during persistent Cps infection.Methods The fusion protein His-CPSIT_p7 was expressed in E.coli BL21 and purified by Ni-NTA affinity chromatography .BALB/c mice were immunized with the recombinant protein to prepare polyclonal antibody for evaluation of the immunogenicity of His-CPSIT_p7 by ELISA.Penicillin sodium was used to establish a model of Cps persistence infection .RT-PCR and Western blot assay were performed to de-tect the expression of CPSIT_p7 at mRNA and protein levels during Cps persistent infection .Results The fusion protein His-CPSIT_p7 was successfully expressed with the use of constructed recombinant expression plasmid pET30 a-CPSIT_p7 and purified .ELISA result showed that the specific antibody titer against CPSIT_p7 reached 1 ∶1 000 000 on the 40th days after immunization .The expression of CPSIT_p7 at mRNA and protein levels were increased in a time-dependent manner in Cps-infected HeLa cells .The peak of mRNA level was reached at the time point of 36 hours after infection , followed by a time-dependent decrease during Cps acute infection .However , the expression of CPSIT_p7 at mRNA and protein levels were not decreased until 60 hours after infection during Cps persistent infection .Conclusion His-CPSIT_p7 protein was suc-cessfully expressed in the prokaryotic expression system and purified , showing an advantage of good immuno-genicity.Highly expressed CPSIT_p7 at mRNA and protein levels were detected during Cps persistent infection. Key words: Chlamydophila psittaci; Cloning and expression; Immunogenicity; Per-sistent infection

Correction: Evaluation of pulmonary dysfunctions and acid–base imbalances induced by Chlamydia psittaci in a bovine model of respiratory infection

Correction about the publication of our article by Ostermann C, Linde S, Siegling-Vlitakis C, Reinhold P: Evaluation of pulmonary dysfunctions and acid–base imbalances induced by Chlamydia psittaci in a bovine model of respiratory infection. Multidiscip Respir Med 2014, 9:10.

Localization and temporal expression of CPSIT_0271 in Chlamydia psittaci-infected cells and its stimula-tory effects on the expression of proinflammatory cytokines by THP-1 cells

Objective To study the intracellular localization and temporal expression of CPSIT_0271 in Chlamydia psittaci-infected cells; and to investigate the effects of recombinant GST-CPSIT_0271 protein on the expression of proinflammatory cytokines including IL-6, IL-1βand TNF-αby THP-1 cells.Methods The gene encoding CPSIT_0271 of Chlamydia psittaci was expressed as fusion protein （ GST-CPSIT_0271 ） in E.coli.The polyclonal antibody was prepared by immunizing BALB /c mice with the purified recombinant pro-tein.Antibody titer was determined by ELISA .Indirect immunofluorescence assay （ IFA） was performed to lo-cate the endogenous CPSIT_0271 protein in C.psittaci-infected cells .The expression characteristics of CPSIT_0271 protein were detected by Western blot in C.psittaci-infected HeLa cells at different time points .The levels of IL-6, IL-1βand TNF-αwere analyzed by ELISA after stimulating THP-1 cells with different concentrations of CPSIT_0271 protein.Results CPSIT_0271 protein was found to express in the chlamydia inclusion of C.psittaci-infected HeLa cells .The expression of CPSIT_0271 protein was detected firstly at 36 h and increased at 48 h after C.psittaci infection.The titer of anti-CPSIT_0271 specific antibody in GST-CPSIT_0271 immu-nized mice reached to 1 ∶16 000.GST-CPSIT_0271 protein increased the levels of IL-6, IL-1βand TNF-αin THP-1 cells in a dose-dependent manner in the range of 2 to 5 μg/ml.The levels of TNF-αand IL-1βreached their peaks at 24 h, and IL-6 level peaked at 48 h upon the stimulation by 5 μg/ml of GST-CPSIT_0271 pro-tein.Conclusion CPSIT_0271 expressed in inclusion bodies of Chlamydia psittaci in the infected cells , sug-gesting it might be a late expression gene .GST-CPSIT_0271 protein shows good immunogenicity and enhances the expressions of IL-6, IL-1βand TNF-αin THP-1 cells. Key words: Chlamydophila psittaci; CPSIT_0271; Cellular localization; Temporal expression; Proin-flammatory cytokines

Purification and immunological characteristics of monoclonal antibody 2H4 against Chlamydia trachomatis pORF5 plasmid protein

Objective To purify and characterize the monoclonal antibody (McAb) against Chlamydia trachomatis pORF5 plasmid protein.Methods The hybridoma cells stably secreting specific McAb against pORF5 were cultured in a large scale,and protein G purification by affinity chromatography was used to purify 2H4 McAb.ELISA was used to determine the antibody titer,and identify McAb isotype.Immunofluorescence assay (IFA) and Western blot were performed to detect McAb specificity.Results The purity of 2H4 antibody was 93％,the titer reached 1:1024,and 2H4 McAb was identified to belong to IgG2a isotype,2H4 McAb reacted strongly with the GST-pORF5 fusion protein and endogenous pORF5 protein expressed by Chlamydia trachomatis serovar A,D,L2,Chlamydia muridarum ( MoPn ),Chlamydia psittaci 6BC,but not other chlamydial plasmid proteins and Chlamydia pneumoniae(Cpn) AR39 strain.Conclusion 2H4 McAb against pORF5 protein was successfully purified with a high titer and specificity which lay a foundation for further study on pORF5 protein structure and function. Key words: Chlamydia trachomatis; pORF5 plasmid protein; Monoclonal antibody; Immunological characteristics

Study on the diagnosis application using recombinant protein of immunodominant region gene of chlamydial protease-like activity factor from Chlamydophila psittaci

Objective To clone and express the immunodominant domain of the chlamydial proteaselike activity factor(CPAF) from Chlamydophila psittaci(Cps) and evaluated the diagnosing value of the recombinant protein in Cps infection.Methods The immunodominant region epitope of CPAF (CPAFm,A196-A450)from Cps was chosen according to bioinformatics analysis and references.The specific primer was designed and the gene was amplified by PCR and then ligated into a pGEX6p-2 vector.Recombinant protein was induced to express by IPTG and analyzed by SDS-PAGE and Western blot.Indirect EL1SA method of serological diagnosis was established with the reorganization protein as coating antigen.One hundred and eighty sera samples from ducks with respiratory tract infection symptoms were detected with the established indirect ELISA and a commercial ELISA-kit to assess the value of the recombinant protein in serodiagnosis.The results were further identified with Western blot.Results Prokaryotic expression vector pGEX6p-2/CPAFm was constructed and a 54x103 fusion protein was attained.The indirect ELISA method was established with reorganization protein for envelope antigen.Using the indirect ELISA to detect Cps lgG positive and negative reference sera,the sensitivity and specificity were both 100％ (20/20).And the recombinant protein has no cross reaction with either Chlamydophila pneumoniae or Chlamydophila trachomatis.The concordance rate between the indirect ELISA and Western blot to 180 ducks sera samples was 100％,while the concordance rate of the commercial ELISA kit was 77.5％-95.0％.Conclusion The prepared recombinant protein of the CPAF immunodominant region epitope gene from Gps can highly benefit on developing new indirect ELISA as methods to detect specific anti-Cps antibodies. Key words: Chlamydophila psittaci; Chlamydial protease-like activity factor; Immunocompetence; Serological diagnosis

Clinical and serological studies in six cases of chlamydial pneumonia

Clinical and serological studies of chlamydial pneumonia were done in six patients (three men and three women). The other three patients had no avian contact and showed almost the same clinical symptom. Acute infection with Chlamydia psittaci and Chlamydia pneumoniae were diagnosed in two patients and in one patient, respectively, by MFA. Because in some cases Chlamydia psittaci pneumonia and Chlamydia pneumoniae pneumonia are difficult to differentiate, it is necessary to use a test that allows different chlamydia species to be distinguished.

Community acquired pulmonary infections in a general hospital

We studied community acquired pulmonary infections in general hospital. Forty-seven outpatients (group I) and 107 inpatients (group II) were analyzed respectively. The mean age of group I was 43.4 years old and that of group II was 57.4 years old. Significant underlying diseases were present in 45% of group I and 62% of group II. In group I, the underlying diseases were chronic respiratory diseases, and in group II, chronic respiratory diseases and other significant diseases such as diabetes mellitus, cardiovascular diseases, malnutrition or malignancy. All of group I and 81 cases of group II were pneumonia. Pleuritis with pneumonia (11), lung abscess or cavitary infection (11), and pyothorax (4) were included in group II. Etiologic organisms were determined in 48.6% of the cases in group I, and 44.0% in group II. Invasive methods such as transtracheal aspiration and percutaneous lung puncture aspiration were very useful for isolation of the pathogen. The pathogens isolated included H. influenzae (17), S. pneumoniae (10), M. pneumoniae (4), C. psittaci (4) in total cases. In group I, H. influenzae was mostly isolated and in group II, S. pneumoniae was mostly isolated and opportunistic pathogens were also isolated. The form of pneumococcal pneumonia was almost always focal pneumonia in this study. There were 8 fatalities (5.2%), all of which were very old or had other serious diseases.

Study of cell populations of bronchoalveolar lavage fluid in patients with pneumonia due to Chlamydia psittaci and Mycoplasma pneumoniae

We have performed bronchoalveolar lavage (BAL) examination in 27 cases; 5 with Chlamydial pneumonia, 7 with Mycoplasmal pneumonia and 15 in the control group (5 non-smokers, 10 smokers), and the following results were obtained. 1. In Chlamydial pneumonia and Mycoplasmal pneumonia, the cell population of alveolar macrophages in BALF decreased (p < 0.01) and that of lymphocytes increased compared with control group (p < 0.01). 2. In all cases of Mycoplasmal pneumonia without peripheral eosinophilia, the cell population of eosinophils in BALF increased compared with cases of Chlamydial pneumonia (p < 0.05). These results indicate that lymphocytes played the main role in the immune host defense in Chlamydial pneumonia, whereas infiltration of lymphocytes and eosinophils into the pneumonic lesion occurred in Mycoplasma pneumoniae infection.

Unanticipated outbreak of Q fever during a study using sheep, and its significance for further projects

Effective measures for protection of laboratory staff against infections due to experiments with pathogens are a challenge for safeguarding against hazards. Investigations on limited epidemic infections and their causes are of high relevance. During an experiment with pregnant sheep 5 of 7 persons who took part in the operation procedures developed Q fever 10 to 24 days after exposure. One sheep aborted spontaneously 3 days after the third experiment. Examinations of the aborted material revealed Coxiella burnetii, Chlamydophila psittaci, and Staphylococcus chromogenes. Coxiella burnetii and Chlamydophila psittaci were also detected in some of the other placentae. This outbreak of Q fever during an experiment with infected sheep affected more than 70% of the people involved with this experiment and shows the high risk of working with the zoonotic agent Coxiella burnetii. Hence, technical, organizational, and personnel measures have to be taken, and laboratory animals are to be monitored to prevent further infections.

Antibodies to Chlamydia psittaci in goats in Botswana

Antibodies to Chlamydia psittaci in goats in Botswana

Studies on the safety of Chlamydia psittaci vaccination in cats.

Studies on the safety of Chlamydia psittaci vaccination in cats.

Experimental conjunctival infection of lambs with a strain of Chlamydia psittaci isolated from the eyes of a sheep naturally affected with keratoconjunctivitis.

Five ram-lambs were inoculated into the left conjunctival sac with the 15R isolate of Chlamydia psittaci, recovered from a sheep with keratoconjunctivitis. A sixth ram-lamb was kept in contact with them. The five lambs developed varying degrees of acute conjunctivitis and 14 days later C psittaci could be recovered from the inoculated eyes, from which Branhamella ovis was also isolated. The eyes were examined regularly for four months; C psittaci could not be re-isolated but the eyes developed varying degrees of follicular conjunctivitis. After four months the sheep were treated with corticosteroids in an attempt to reactivate a latent chlamydial infection but no chlamydiae could be isolated. Five months after the start of the experiment the six lambs were inoculated with 15R into the left conjunctival sacs. Acute conjunctivitis developed which was not as severe as after the first inoculation, but C psittaci could only be recovered from the left eyes of three sheep three days after inoculation. The eyes remained chronically affected by follicular conjunctivitis. Six months after the start of the experiment the left eyes were again inoculated with 15R; on this occasion acute conjunctivitis did not develop and chlamydiae could not be isolated. Chronic follicular conjunctivitis persisted until the experiment was terminated three months later.

Serological detection of phage infection in Chlamydia psittaci recovered from ducks.

Antiserum prepared against a phage which infects a Chlamydia psittaci isolate recovered from domestic ducks was used to screen other recent avian C psittaci isolates by indirect immunofluorescence. Two more phage infected strains from ducks were discovered. However, phage was not detected in every isolate examined from common source ducks, although such birds are likely to be infected with the same C psittaci strain. Moreover, phage could not always be demonstrated by indirect immunofluorescence in McCoy cell monolayers infected with the phage-containing strain. The results suggest that phage infection is probably an integral part of duck chlamydiosis in the United Kingdom at present, but that the infection is often cryptic.

Simple transport medium for the isolation of Chlamydia psittaci from clinical material.

Infectious elementary bodies of Chlamydia psittaci in tissue samples from field cases of enzootic abortion were placed in five different transport media (A to E). In one medium, in the absence of refrigerative storage, the organism remained viable for 30 days and at 4 degrees C for 34 days. This was medium D; it consisted of sucrose (74.6 g/litre), K2HPO4 (1.237 g/litre), L-glutamic acid (0.721 g/litre), fetal calf serum (10 per cent v/v), vancomycin and streptomycin (100 micrograms/ml) and nystatin and gentamicin (50 micrograms/ml). Samples of this transport medium were supplied to veterinary investigation centres throughout the UK. Of 1862 samples submitted for diagnosis of enzootic abortion only 1.55 per cent were so contaminated that chlamydiae could not be detected. This transport medium permits the isolation of C psittaci from clinical material for up to about one month, even in the absence of conventional storage facilities.

Attachment defect in mouse fibroblasts (L cells) persistently infected with Chlamydia psittaci.

Almost all the cells in populations of mouse fibroblasts (L cells) persistently infected with the 6BC strain of Chlamydia psittaci were immune to superinfection with high multiplicities of C. psittaci, whether or not the L cells contained visible chlamydial inclusions. As ascertained by experiments with 14C-labeled C. psittaci, immunity to superinfection resulted from the failure of added chlamydiae to attach to persistently infected host cells. However, when exogenous C. psittaci was introduced into persistently infected L cells by centrifuging the inoculum onto host cell monolayers or by pretreating the monolayers with diethylaminoethyl-dextran, these chlamydiae produced expected numbers of infectious progeny. Persistently infected L cells were associated in an unknown way with a C. psittaci population that entered the host cells only with the aid of centrifugation or pretreatment with diethylaminoethyl-dextran. Inclusion-free, persistently infected L cells appeared to present at least two separate hindrances to chlamydial activity: blockage of the attachment of exogenous elementary bodies to persistently infected host cells and prevention of the initiation of chlamydial multiplication by means of a normal developmental cycle in the absence of added C. psittaci.

Diagnostic Specificity of Immunoglobulin M (IgM) Response in Differentiating Legionnaires' Disease from Psittacosis

Specific IgM and IgG antibody responses to Legionella pneumophila (LDB) and Chlamydia psittaci (PSI) in serum specimens from 22 cases of Legionnaires' Disease (LD) were examined by micro-immunofluorescence (IF) tests to explore the diagnostic significance of the IgM antibody response. Serial samples from 5 patients with LD showed greater than or equal to 4-fold changes in IgG antibody against LDB and PSI. All 5 patients possessed IgM antibodies against LDB but not against PSI. In single convalescent serum samples from 17 additional cases, 16 exhibited IgG and 15 showed IgM antibodies against LDB; all 17 exhibited IgG but not IgM antibodies against PSI. The IgM antibody response appears more specific than the corresponding IgG response in the serodiagnosis of LD, and may be valuable in differentiating LDB infections from those due to PSI.

On heterochrosis in Australian Psittaci

On heterochrosis in Australian Psittaci