More than classical Chlamydia psittaci in urban pigeons.
TL;DR: The combined use of highly specific and sensitive molecular assays facilitated the detection of atypical serovars of C. psittaci, as well as other species of Chlamydia, such as C. pecorum and C. abortus, which raises the question of their epidemiological importance and possible role as pathogens.
About: This article is published in Veterinary Microbiology.The article was published on 2012-06-15. It has received 89 citations till now. The article focuses on the topics: Chlamydia psittaci & Chlamydiaceae.
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TL;DR: Comparative genome analysis involving the type strains of currently accepted Chlamydiaceae species and the designated type strains representing the two new clades confirmed that the latter could be classified into two different species as their average nucleotide identity (ANI) values were always below 94%, both with the closest relative species and between themselves.
159 citations
TL;DR: The historical background and the most important developments in the field of animal chlamydial research in the past 5 years with a special focus on pathology are summarized, the current nomenclature is summarized, critical thoughts about diagnostics are presented, and an update on chlamYDial infections in domesticated animals such as livestock, companion animals and birds are given.
Abstract: Chlamydiae have a worldwide distribution causing a wide range of diseases in human hosts, livestock, and companion animals as well as in wildlife and exotic species. Moreover, they can persist in their hosts as asymptomatic infections for extended periods of time. The introduction of molecular techniques has revolutionized the Chlamydia field by expanding the host range of known chlamydial species but also by discovering new species and even new families of bacteria in the broader order Chlamydiales. The wide range of hosts, diseases, and tissues affected by chlamydiae complicate the diagnosis such that standard diagnostic approaches for these bacteria are rare. Bacteria of the Chlamydiales order are small and their inclusions are difficult to detect by standard microscopy. With the exception of avian and ovine chlamydiosis, macroscopic and/or histologic changes might not be pathognomic or indicative for a chlamydial infection or even not present at all. Moreover, detection of chlamydial DNA in specimens in the absence of other methods or related pathological lesions questions the significance of such findings. The pathogenic potential of the majority of recently identified Chlamydia-related bacteria remains largely unknown and awaits investigation through experimental or natural infection models including histomorphological characterization of associated lesions. This review aims to summarize the historical background and the most important developments in the field of animal chlamydial research in the past 5 years with a special focus on pathology. It will summarize the current nomenclature, present critical thoughts about diagnostics, and give an update on chlamydial infections in domesticated animals such as livestock, companion animals and birds, as well as free-ranging and captive wild animals such as reptiles, fish, and marsupials.
100 citations
TL;DR: Ulastructural analysis, comparative sequence analysis, and determination of the whole genome sequence confirmed the relatedness of the new isolate to members of the Chlamydiaceae, while, at the same time demonstrating a unique position outside the currently recognized species of this family.
Abstract: Investigations conducted on feral African Sacred Ibises (Threskiornis aethiopicus) in western France led to the isolation of a strain with chlamydial genetic determinants. Ultrastructural analysis, comparative sequence analysis of the 16S rRNA gene, ompA, and of a concatenate of 31 highly conserved genes, as well as determination of the whole genome sequence confirmed the relatedness of the new isolate to members of the Chlamydiaceae, while, at the same time demonstrating a unique position outside the currently recognized species of this family. We propose to name this new chlamydial species Chlamydia ibidis.
94 citations
Cites background from "More than classical Chlamydia psitt..."
...Additionally, new and hitherto non-classified chlamydial agents were recently described in chickens [6,16,29], pigeons [11,12], and sea gulls [10]....
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TL;DR: Biological and clinical features, therapeutic implications and future perspectives of these lymphoma-microbial associations are discussed in this review.
72 citations
Cites background from "More than classical Chlamydia psitt..."
...[58] Sachse K, Kuehlewind S, Ruettger A, Schubert E, Rohde G....
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...Cp DNA can be detected in feces of 45–77% of pigeons in urban areas [58]....
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TL;DR: This study indicates that C. gallinacea is the endemic chlamydial species in chickens, whereas C. psittaci dominates only in pigeons, and further studies are required to address the specific conditions under which C.gallinacea could act as an avian pathogen and possibly also a zoonotic agent.
Abstract: To investigate the prevalence and diversity of Chlamydia spp. in domestic birds in China, oral and cloacal swabs of healthy chickens, ducks, geese and pigeons were collected nationwide from live-animal markets and examined by Chlamydia spp. 23 S rRNA gene FRET-PCR followed by high-resolution melting curve analysis and confirmatory sequencing. Overall, 26.2% of the birds (602/2,300) were positive for Chlamydia spp. and five Chlamydia spp. were identified. While occasional detection of C. suis and C. muridarum in poultry is reported here for the first time, the predominant chlamydial agent was C. gallinacea representing 63.8% of all positives (384/602) and 81.2% of positive chickens (359/442). Analysis of the C. gallinacea ompA phylogeny revealed at least 13 well segregated variants (serovars). Seven-month monitoring of C. gallinacea-infected chickens indicated that the infection was persistent. C. gallinacea-infected chickens remained without overt clinical disease, but showed body weight gains significantly reduced by 6.5-11.4% beginning in week 3 post-infection. This study indicates that C. gallinacea is the endemic chlamydial species in chickens, whereas C. psittaci dominates only in pigeons. Further studies are required to address the specific conditions under which C. gallinacea could act as an avian pathogen and possibly also a zoonotic agent.
72 citations
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TL;DR: A reclassification of the order Chlamydiales and its current taxa is proposed in this article, which retains currently known strains with > 90% 16S rRNA identity in the family Chlamdianaceae and separates other chlamydia-like organisms that have 80-90% 16s rRNA relatedness to the chlamydiaceae into new families.
Abstract: The current taxonomic classification of Chlamydia is based on limited phenotypic, morphologic and genetic criteria This classification does not take into account recent analysis of the ribosomal operon or recently identified obligately intracellular organisms that have a chlamydia-like developmental cycle of replication Neither does it provide a systematic rationale for identifying new strains In this study, phylogenetic analyses of the 16S and 23S rRNA genes are presented with corroborating genetic and phenotypic information to show that the order Chlamydiales contains at least four distinct groups at the family level and that within the Chlamydiaceae are two distinct lineages which branch into nine separate clusters In this report a reclassification of the order Chlamydiales and its current taxa is proposed This proposal retains currently known strains with > 90% 16S rRNA identity in the family Chlamydiaceae and separates other chlamydia-like organisms that have 80--90% 16S rRNA relatedness to the Chlamydiaceae into new families Chlamydiae that were previously described as ‘Candidatus Parachlamydia acanthamoebae’ Amann, Springer, Schonhuber, Ludwig, Schmid, Muller and Michel 1997, become members of Parachlamydiaceae fam nov, Parachlamydia acanthamoebae gen nov, sp nov ‘Simkania’ strain Z becomes the founding member of Simkaniaceae fam nov, Simkania negevensis gen nov, sp nov The fourth group, which includes strain WSU 86--1044, was left unnamed The Chlamydiaceae, which currently has only the genus Chlamydia, is divided into two genera, Chlamydia and Chlamydophila gen nov Two new species, Chlamydia muridarum sp nov and Chlamydia suis sp nov, join Chlamydia trachomatis in the emended genus Chlamydia Chlamydophila gen nov assimilates the current species, Chlamydia pecorum, Chlamydia pneumoniae and Chlamydia psittaci, to form Chlamydophila pecorum comb nov, Chlamydophila pneumoniae comb nov and Chlamydophila psittaci comb nov Three new Chlamydophila species are derived from Chlamydia psittaci: Chlamydophila abortus gen nov, sp nov, Chlamydophila caviae gen nov, sp nov and Chlamydophila felis gen nov, sp nov Emended descriptions for the order Chlamydiales and for the family Chlamydiaceae are provided These families, genera and species are readily distinguished by analysis of signature sequences in the 165 and 235 ribosomal genes
920 citations
TL;DR: 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.
223 citations
TL;DR: Examination of dilution series of a plasmid standard carrying the target sequence from Chlamydia trachomatis and genomic DNA of this organism revealed that a single PCR-amplifiable target copy was sufficient to obtain a specific hybridization pattern.
220 citations
TL;DR: Although feral pigeons pose sporadic health risks to humans, the risk is very low, even for humans involved in occupations that bring them into close contact with nesting sites, and the immunocompromised patient may have a nearly 1000-fold greater risk of acquiring mycotic disease from feral pigeon and their excreta than does the general population.
177 citations
TL;DR: The dramatic changes that have occurred in the taxonomy of bacteria known as Chlamydia create opportunities for veterinarians to carry out epidemiological studies of chlamydiae that previously were not possible, and DNA-based testing methods are now available that distinguish different chlamydial families, genera, and species.
169 citations