Taher Harkinezhad

Chlamydophila psittaci infections in birds: a review with emphasis on zoonotic consequences.

The first part of the present review gives an overview on the history of infectious agents of the order Chlamydiales and the general infection biology of Chlamydophila (C.) psittaci, the causative agent of psittacosis. In the second part, the classification of C. psittaci strains, as well as issues of epidemiology of avian chlamydiosis., disease transmission routes, clinical disease, public health significance, present legislation and recommendations for prevention and control are reviewed.

Chlamydophila psittaci Transmission from Pet Birds to Humans

We studied zoonotic transmission of Chlamydophila psittaci in 39 breeding facilities for Psittaciformes (cockatoos, parrots, parakeets, lories) that frequently used antimicrobial drugs. Genotypes A or E/B were detected in 14.9% of humans at these facilities. Information on antimicrobial drug use in Psittaciformes and a C. psittaci vaccine are urgently required.

Chlamydial infections in duck farms associated with human cases of psittacosis in France.

Five severe cases of psittacosis in individuals associated with duck farms were notified in France between January and March 2006. Diagnostic examination included serology and/or molecular detection by PCR from respiratory samples. As a consequence, we investigated all duck flocks (n=11) that were housed in the three farms where human infections occurred. While serology by complement fixation test was negative for all samples, cloacal and/or tracheal chlamydial excretion was detected by PCR in all three units. Notably, one duck flock was tested strongly positive in 2 of the 3 affected farms, and Chlamydophila (C.) psittaci strains were isolated from cloacal and/or tracheal swab samples from both farms. Human samples and duck isolates exhibited the same PCR-RFLP restriction pattern, which appeared to be an intermediate between genotypes A and B. Analysis of ompA gene sequences and comparison to those of the type strains showed that the isolates could not be strictly assigned to any of the generally accepted genotypes of C. psittaci. Further analysis by MLVA of the PCR-positive human samples revealed two distinct patterns, which were related to previously isolated C. psittaci duck strains.

Prevalence of Chlamydophila psittaci infections in a human population in contact with domestic and companion birds

Chlamydophila psittaci infections in humans are underestimated. We investigated the occurrence of C. psittaci in a Belgian population of 540 individuals. Data were from a population survey (n=2524) of apparently healthy community-dwelling subjects aged 35-55 years. Pharyngeal swabs and blood were taken. Individuals completed a questionnaire on professional and nonprofessional activities, smoking habits, medical history and contact frequency with different bird species. Swabs were analysed by a C. psittaci-specific and a Chlamydophila pneumoniae-specific PCR. Sera were tested by a recombinant C. psittaci major outer-membrane protein-based ELISA, a C. psittaci whole organism-based ELISA (Serion) and a micro-immunofluorescence test (Focus Diagnostics). Results confirmed our suspicion about the underestimation of psittacosis in Belgium. Psittaciformes and racing pigeons were the main infection source. Women with excessive alcohol intake defined as a mean intake of >2 units daily were more frequently infected than men. We analysed the effect of seropositivity and/or PCR positivity on inflammation (white blood cell count, high-sensitivity C-reactive protein, fibrinogen). In general, seropositivity showed a trend to slightly higher levels of inflammatory variables (all non-significant), whilst PCR positivity showed a trend to no effect or even lower inflammatory levels.

Chlamydophila psittaci Zoonotic Risk Assessment in a Chicken and Turkey Slaughterhouse

ABSTRACT Chlamydophila psittaci causes respiratory disease in poultry and can be transmitted to humans. We conducted a C. psittaci zoonotic risk assessment study of a chicken and turkey slaughterhouse. Eighty-five percent of the slaughtered chicken flocks tested positive by PCR and culture. Genotype D was discovered. Fifty-seven percent of the slaughtered turkey flocks tested positive by PCR and culture. Genotype D was present. For the chicken slaughterhouse employees, 7.5% and 6% tested positive for C. psittaci by PCR and culture, respectively. In the turkey slaughterhouse, 87% and 61% of the employees tested positive by PCR and culture, respectively. All genotyped human samples contained genotype D. Using stationary bioaerosol monitoring by means of an MAS-100 ecosampler and ChlamyTrap collection medium, chlamydial DNA, and viable organisms were detected in both the chicken and turkey slaughterhouses. Positive air samples were most frequently found in the animal reception area and evisceration room. Zoonotic transmissions were very common, especially from processed turkeys. Accurate diagnostic monitoring and reporting of C. psittaci infections should be promoted in poultry workers.

Specific-pathogen-free pigs as an animal model for studying Chlamydia trachomatis genital infection

ABSTRACT The purpose of the present study was to evaluate pigs as a large-animal model for female genital infection with two Chlamydia trachomatis human serovar E strains. Sixteen-week-old specific-pathogen-free female pigs (gilts) were intravaginally infected with the trachoma type E reference strain Bour or the urogenital serovar E strain 468. Several conclusions can be drawn from our findings on the pathogenicity of a primary C. trachomatis genital infection in gilts. First of all, we demonstrated that the serovar E strains Bour and 468 could ascend in the genital tract of gilts. The serovar E strains could replicate in the superficial columnar cervical epithelium and in the superficial epithelial layer of the uterus, which are known to be the specific target sites for a C. trachomatis genital infection in women. Second, inflammation and pathology occurred at the replication sites. Third, the organisms could trigger a humoral immune response, as demonstrated by the presence of immunoglobulin M (IgM), IgG, and IgA in both serum and genital secretion samples. Our findings imply that the pig model might be useful for studying the pathology, pathogenesis, and immune response to a C. trachomatis infection of the genital system.

Evaluation of the prophylactic use of ovotransferrin against chlamydiosis in SPF turkeys.

Chlamydophila (C.) psittaci infections are highly prevalent in turkeys and the economical and public health importance of these infections has been recognized since 1950. As there are no vaccines, antibiotic treatment (tetracylines, enrofloxacine) is often needed to allow marketing of poultry. In this study, we explored the use of ovotransferrin (ovoTF), a natural anti-microbial protein, in preventing an experimental C. psittaci infection in specific pathogen free (SPF) turkeys. Turkeys were treated with aerosolized ovoTF prior to the infection. Groups 1 and 2 received a single dose of 10 and 5 mg ovoTF per turkey, respectively. Group 3 received a daily dose of 5mg ovoTF per turkey during 12 days. Group 4 served as untreated, infected control group. Turkeys were aerosol infected using 10(6) TCID(50) of the virulent C. psittaci serovar/genotype D strain 92/1293. Birds were monitored (clinical signs, bacterial excretion) during 12 subsequent days before being necropsied. At necropsy, pathology and C. psittaci replication in various tissues was examined. A single dose of 10mg ovoTF and a repeated daily dose of 5mg ovoTF could not prevent the birds from becoming infected with C. psittaci, but they significantly reduced the outcome of the infection. A single dose of 5mg ovoTF had no influence on the outcome of the infection as compared to the non-treated infected controls. Our results demonstrate the anti-chlamydial effect of ovoTF in vivo and present a base for further research on practical applications of ovoTF on turkey farms.

Protection of budgerigars (Melopsittacus undulatus) against Chlamydophila psittaci challenge by DNA vaccination

Plasmid DNA (pcDNA1::MOMP A) expressing the major outer membrane protein (MOMP) of Chlamydophila psittaci genotype A strain 89/1051 has been tested for its ability to induce protective immunity against Cp. psittaci challenge in budgerigars. Eight pairs of male and female budgerigars were housed in eight separate bird cages placed in two negative pressure isolators, four cages per group. All budgerigars were immunised twice intramuscularly with 100 microasmid DNA. Both groups received a primary DNA inoculation at day 0 followed by a booster inoculation 3 weeks later. Group 1 received pcDNA1::MOMP A, while group 2 received the placebo vaccine pcDNA1. Budgerigars were challenged by aerosol 2 weeks following the booster vaccination. The challenge consisted of 10(8) TCID(50) of the homologous Cp. psittaci genotype A strain. Cloacal and pharyngeal swabs of all budgerigars, taken prior to the experimental infection were negative in both PCR and culture. However, all budgerigars showed low pre-existing serum antibody titres. This indicates that animals were previously infected. Nevertheless, DNA immunisation could significantly reduce clinical signs, macroscopic lesions, pharyngeal and cloacal excretion as well as chlamydial replication, even in the presence of pre-existing serum antibodies, as compared to the placebo-vaccinated controls.

Effect of Aflatoxin B1 on Growth of Bovine Mammary Epithelial Cells in 3D and Monolayer Culture System.

PURPOSE Many studies have been showed transfer of aflatoxins, toxins produced by Aspergillus flvaus and Aspergillus parasiticus fungi, into milk. These toxins are transferred into the milk through digestive system by eating contaminated food. Due to the toxicity of these materials, it seems that it has side effects on the growth of mammary cells. Therefore, the present work aimed to investigate possible toxic effects of aflatoxin B1 (AFB1) on bovine mammary epithelial cells in monolayer and three-dimensional cultures. METHODS Specimens of the mammary tissue of bovine were sized out in size 2×2 cm in slaughterhouse. After disinfection and washing in sterile PBS, primary cell culture was performed by enzymatic digestion of tissue with collagenase. When proper numbers of cells were achieved in monolayer culture, cells were seeded in a 24-well culture plate for three-dimensional (3D) culture in Matrigel matrix. After 21 days of 3D culture and reaching the required number of cells, the concentrations of 15, 25 and 35 µL of AFB1 were added to the culture in quadruplicate and incubated for 8 hours. Cellular cytotoxicity was examined using standard colorimetric assay and finally, any change in the morphology of the cells was studied by microscopic technique. RESULTS Microscopic investigations showed necrosis of the AFB1-exposed cells compared to the control cells. Also, bovine mammary epithelial cells were significantly affected by AFB1 in dose and time dependent manner in cell viability assays. CONCLUSION According to the results, it seems that AFB1 can induce cytotoxicity and necrosis in bovine mammary epithelial cells.

Evaluation of STAT5A Gene Expression in Aflatoxin B1 Treated Bovine Mammary Epithelial Cells.

PURPOSE Aflatoxin B1 (AFB1) is a potent mycotoxin which has been produced by fungi such as Aspergillus flavus and Aspergillus parasiticus as secondary metabolites due to their growth on food stuffs and induces hepatocellular carcinoma in many animal species, including humans. In the present study, the effect of AFB1 on STAT5A gene expression was investigated in bovine mammary epithelial cells using real time RT-PCR. METHODS Bovine mammary epithelial cells were seeded in a 24-well culture plate for three-dimensional (3D) culture in Matrigel matrix. After 21 days of 3D culture and reaching the required number of cells, cells were treated with AFB1 and incubated for 8 h. For real time PCR reaction, total RNA from the cultured and treated cells was extracted and used for complementary DNA synthesis. RESULTS The expression of STAT5A gene was significantly down regulated by AFB1 in dose- dependent manner and led to the reduction of proliferation and differentiation of epithelial cells, which has direct effect in milk protein quantity and quality. CONCLUSION According to the results, it seems that down regulation of STAT5A gene in AFB1-treated cells maybe due to DNA damage induced by AFB1 in bovine mammary epithelial cells.