Q fever (coxiellosis) is an infectious disease of animals and humans, caused by.C. burnetii and widely distributed throughout the world. It is known that people and animals acquire the disease predominantly.via inhalation of infectious aerosols. The possibility of transmission of the pathogen by the alimentary route is still a matter of debate and remains controversial. Therefore the aim of this study was to fill the gaps in knowledge of oral transmission of.C. burnetii by conducting biological tests on the guinea pig model.
Material and Methods
Guinea pigs, divided into five groups comprising a negative control and four experimental groups, received specified concentrations of.C. burnetii per os. To determine the presence of specific antibodies, blood samples were tested using CFT. Also, internal organs collected during necropsy were screened by a real-time PCR targeting I.1111. Additionally, histopathological evaluation of the tissues was performed.
The presence of antibodies and pathogen DNA in caecum was confirmed in one guinea pig from experimental group IV..C. burnetii was also detected in testicular tissue collected from one animal of experimental group II.
The presence of pathogen DNA in the testicular tissue indicates that infection spreads haematogenously. In the majority of experimental animals specific antibodies and genetic material of.C. burnetii were not detected. This fact suggests that development of infection depends on many factors, such as animal immune status.
Chlamydiales, one of the oldest bacterial orders in evolutionary terms, are widespread among animals. Blinding trachoma, a disease caused by Chlamydia trachomatis, was already known in ancient times, whereas modern reports on psittacosis date from 1879. Though these pathogens have long been known and lead to serious health problems both in human and animals, data on Chlamydiales biology has been limited. It is due to their intracellular life style and complex developmental cycle. New molecular biological methods have been recently developed expanding the possibilities of chlamydial research and diagnosis. This paper reviews data concerning avian chlamydiosis, its aetiological agent C. psittaci, newly proposed species isolated from birds, namely C. ibidis sp. nov., C. avium sp. nov., and C. gallinacea sp. nov., and their zoonotic potential.
Q fever is a zoonotic disease caused by Coxiella burnetii. The main source of infection are ruminants (cattle, sheep, and goats). C. burnetii is excreted via birth products, vaginal mucus, milk, and faeces. Raw milk is considered useful for epidemiological examinations of animals and evaluation of infection dynamics at the herd level. This article summarises data on prevalence studies on C. burnetii in bulk-tank milk in different European countries with the means of serological tests and PCR. It also summarises the results of studies to evaluate the actual risk of disease transmission to humans through consumption of raw milk. Moreover, the available diagnostic tools for detection C. burnetii infection are presented.
The outbreak of chlamydiosis in one of the western provinces of Poland, was diagnosed accidentally as a concurrent infection in a commercial laying hen flock during an outbreak of fowl pox. For histological examination, skin and subcutaneous tissue samples from lesions on heads of the birds were collected. Swabs from throat and trachea have been examined by nested PCR, real-time PCR, and partial ompA sequencing. Detailed electron microscopy analysis revealed fowl pox intracytoplasmic inclusions, called Bollinger bodies, and the presence of other intracytoplasmic inclusions; specific for Chlamydia sp. Results of nested PCR confirmed the presence of Chlamydiaceae sp. in two tested samples. Surprisingly, one of the two Chlamydiaceae-positive cases turned out to be infected with a non-classified strain. Results of real-time PCR and sequencing confirmed the presence of a new Chlamydia species that has not been found in Poland to date. Partial sequencing and BLAST analysis of ompA gene sequence confirmed the highest homology to non-classified poultry strains of Chlamydia sp. that were previously detected in Germany and France. The zoonotic potential and the exact taxonomic status of this atypical strain have yet to be defined.
The aim of the study was to assess the seroprevalence of Coxiella burnetii in cattle herds in different regions of Poland. A total of 1150 serum samples collected from 443 cattle herds from 14 provinces were tested using complement fixation test. The seroprevalence was different in individual regions of Poland. The average percentage of seropositive herds was 40.41% and these herds were identified in each province tested.
Changes in the taxonomy of the order Chlamydiales, after its separation from the order Rickettsiales, were presented. These changes resulted in the recognition of the following families: Chlamydiaceae, Chlavichlamydiaceae, Criblamydiaceae, Parachlamydiaceae, Piscichlamydiaceae, Rhabdochlamydiaceae, Simkaniaceae, and Waddliaceae. Other described changes concerned particularly the family Chlamydiaceae. Its genus Chlamydia was divided into Chlamydia and Chlamydophila. However, in the following years, a revision to the single original genus was made, based upon phylogenetic analysis of 16S and 23S rRNA genes of the strains belonging to these two taxonomic units. The review also discusses other families outside the family Chlamydiaceae, which contain so-called Chlamydia-related or Chlamydia-like organisms. Members of each family share a 16S rDNA gene sequence similarity >90%. Furthermore, characterisation of the pathogenecity is presented, focusing especially on the representatives of the family Chlamydiaceae, which cause animal infections, and describing their zoonotic potential. Available data on this topic, connected with the representatives of other families, were mentioned.
Introduction: Mycoplasma bovis is one of the main pathogens involved in cattle pneumonia. Other mycoplasmas have also been directly implicated in respiratory diseases in cattle. The prevalence of different Mycoplasma spp. in cattle affected by respiratory diseases and molecular characteristics of M. bovis field strains were evaluated. Material and Methods: In total, 713 nasal swabs from 73 cattle herds were tested. The uvrC gene fragment was amplified by PCR and PCR products were sequenced. PCR/DGGE and RAPD were performed. Results: It was found that 39 (5.5%) samples were positive for M. bovis in the PCR and six field strains had point nucleotide mutations. Additionally, the phylogenetic analysis of 20 M. bovis field strains tested with RAPD showed two distinct groups of M. bovis strains sharing only 3.8% similarity. PCR/DGGE analysis demonstrated the presence of bacteria belonging to the Mollicutes class in 79.1% of DNA isolates. The isolates were identified as: Mycoplasma bovirhinis, M. dispar, M. bovis, M. canis, M. arginini, M. canadense, M. bovoculi, M. alkalescens, and Ureaplasma diversum. Conclusion: Different Mycoplasma spp. strains play a crucial role in inducing respiratory diseases in cattle.
Introduction: The study was conducted to investigate the prevalence and genetic diversity of Chlamydia spp. in poultry in Poland and estimate possible transmission to humans.
Material and Methods: Molecular diagnostic methods followed by sequencing and strain isolation were used on cloacal/faecal swabs collected from 182 apparently healthy poultry flocks including chickens, turkeys, ducks, and geese. Serum samples obtained from people exposed (study group) and non-exposed (control group) to birds were tested by complement fixation test to acquire data on Chlamydia spp. antibody level.
Results: Overall, 15.9% of the tested flocks were Chlamydiaceae-positive and three Chlamydia spp. were identified. Predominant chlamydial agent found was C. gallinacea occurring in 65.5% of all positive poultry flocks and in 73.0% of positive chicken flocks. The sequences from four chicken flocks were assigned to C. abortus, whereas C. psittaci was confirmed in one duck and one goose flock. The analysis of ompA variable domains revealed at least nine genetic variants of C. gallinacea. Chlamydial antibodies were detected in 19.2% of human serum samples in the study group in comparison with 10.8% in the controls.
Conclusion: The obtained results confirm that chlamydiae are common among chicken flocks in Poland with C. gallinacea as a dominant species. Moreover, the presence of C. abortus in chickens is reported here for the first time. Further investigation should focus on possible zoonotic transmission of C. gallinacea and C. abortus as well as potential pathogenic effects on birds’ health and poultry production.
Introduction:Coxiella (C.) burnetii, the aetiological agent of Q fever, is able to modulate the macrophage/T-lymphocyte axis in an infected organism and impair synthesis of monokines and lymphokines.
Material and Methods: The purpose of this research was to determine the levels of the cytokines that play a key role in the response to C. burnetii antigens (IL-1β, IL-2, IL-6, IL-10, IFN-γ and TNF-α) in the serum of animals originating from an infected herd prior to vaccination (day 0) and at 1, 7, and 21 days afterwards.
Results: The vaccination of animals did not affect the production of IL-6, IL-1β, or IL-2. The serum levels of these cytokines were too low to measure in most of the samples. The initial levels of TNFα, IFNγ, and IL-10 were higher in seropositive than in seronegative animals, although significant differences between seropositive shedders and seropositive nonshedders appeared only in the levels of IFNγ and IL-10. Additionally, the course of the post-vaccination response concerning these two cytokines was different among seronegative nonshedders, seropositive nonshedders, and seropositive shedders.
Conclusion: It seems that analysis of the IFNγ and IL-10 concentrations in animal blood serum may have some practical value in an assessment of the health status of seropositive animals and post-vaccination response.
The main objective of this study was to assess the occurrence of Chlamydia spp. in Polish swine herds by using serological, molecular, and histological methods as well as by clinical manifestation of the suspected infection when reproductive disorders were taken into account. The seroprevalence among examined animals was 5.65% (96/1698), whereas molecular assessment of the pathogen was negative (0/298). The results of our investigation showed that Chlamydia spp. infection in swine may be suspected more often based on clinical manifestation or histological examination than serological or molecular methods.