Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
emended description of the order chlamydiales, proposal of parachlamydiaceae fam. nov. and simkaniaceae fam. nov., each containing one monotypic genus, revised taxonomy of the family chlamydiaceae, including a new genus and five new species, and standards for the identification of organisms.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 ...199910319462
pcr-based detection of chlamydial infection in swine and subsequent pcr-coupled genotyping of chlamydial omp1-gene amplicons by dna-hybridization, rflp-analysis, and nucleotide sequence analysis.lung and intestine of 49 pigs with respiratory diseases and endocervical swabs from 205 sows with reproductive disorders were investigated for chlamydial infection by polymerase chain reaction. pcr primers targeted dna sequences on the chlamydial omp1 or omp2 genes. pcr amplicons were generated from 49.0% of pigs with respiratory disease, from 60.0% of sows with reproductive disorders, from 24.5% of respiratory healthy controls, but from no endocervical swabs from fertile sows. by dna hybridizat ...200011117968
intestinal lesions caused by a strain of chlamydia suis in weanling pigs infected at 21 days of age.the objective of this study was to determine whether a strain of chlamydia suis shown previously to be an intestinal pathogen in gnotobiotic piglets could cause diarrhea and intestinal lesions in young weanling pigs. pigs from 2 sows were randomly assigned to 2 groups. group 1 included 13 pigs that were weaned at 24 hours of age and then housed in isolator units and fed milk replacer and unmedicated starter ration. group 2 included 8 pigs that nursed their respective sows, consumed unmedicated s ...200010826836
characterization of the rnpb gene and rnase p rna in the order chlamydiales.the sequence of the rnase p rna gene (rnpb) was determined for 60 strains representing all nine species in the family chlamydiaceae and for the related chlamydiales species, parachlamydia acanthamoebae and simkania negevensis. these sequences were used to infer evolutionary relationships among the chlamydiaceae. the analysis separated chlamydophila and chlamydia into two lineages, with chlamydophila forming three distinct clusters: the chlamydophila pneumoniae strains; the chlamydophila pecorum ...200010826799
growth and development of tetracycline-resistant chlamydia suis.tetracycline (tet) is a front-line antibiotic for the treatment of chlamydial infections in both humans and animals, and the emergence of tet-resistant (tet(r)) chlamydia is of significant clinical importance. recently, several tet(r) chlamydial strains have been isolated from swine (sus scrofa) raised in production facilities in nebraska. here, the intracellular development of two tet(r) strains, r19 and r27, is characterized through the use of tissue culture and immunofluorescence. the strains ...200111451674
protein signatures distinctive of chlamydial species: horizontal transfers of cell wall biosynthesis genes glmu from archaea to chlamydiae and mura between chlamydiae and streptomyces.chlamydiae are major human and animal pathogens. based on alignments of different protein sequences, a number of conserved indels (insertion/deletions) were identified that appear to be unique and distinctive characteristics of the chlamydial species. the identified signatures include one 16 aa and two single aa inserts in the enzyme udp-n-acetylglucosamine 1-carboxyvinyltransferase (mura), a 1 aa insert in protein synthesis elongation factor p (ef-p), a 1 aa insert in the mg(2+) transport prote ...200212177347
expression of the major outer membrane protein (momp) of chlamydophila abortus, chlamydophila pecorum, and chlamydia suis in escherichia coli using an arabinose-inducible plasmid vector.the ompa genes encoding the 40 kda major outer membrane protein (momp) of chlamydophila (ch.) abortus, ch. pecorum, and chlamydia (c.) suis were cloned into the arabinose-inducible plasmid vector pbadmychis, and recombinant momps (rmomp) from the three chlamydial species were expressed at high levels in escherichia (e.) coli. the proteins lacking the 22 aa n-terminal signal peptide were expressed as insoluble cytoplasmic inclusion bodies which were readily purified using immobilized metal-affini ...200314633208
primary cultures of female swine genital epithelial cells in vitro: a new approach for the study of hormonal modulation of chlamydia infection.previous studies have demonstrated that female reproductive hormones influence chlamydial infection both in vivo and in vitro. due to the reduced availability of human genital tissues for research purposes, an alternative hormone-responsive model system was sought to study chlamydial pathogenesis. mature female swine eliminated from breeding programs were selected as the animals of choice because of the similarity of a sexually transmitted disease syndrome and sequelae in swine to a disease synd ...200312874351
detection of chlamydia suis from clinical specimens: comparison of pcr, antigen elisa, and culture.cell culture is still widely regarded as the gold standard in chlamydial diagnosis despite its well-known limitations in terms of sensitivity. on the other hand, the polymerase chain reaction (pcr) has emerged as a promising alternative because of rapidity and high sensitivity. however, validation of methodologies is required before the issue of standardization can be addressed. in the present study, 109 clinical samples (organ tissue, nasal, and faecal swabs) from pigs experimentally infected w ...200312782378
growth characteristics of porcine chlamydial strains in different cell culture systems and comparison with ovine and avian chlamydial strains.porcine chlamydiaceae were cultivated under various culture conditions and we compared their growth characteristics with those of ruminant and avian strains. the combination of centrifugation assisted cell culture infection and cycloheximide treatment of vero cell coverslip cultures provided the highest inclusion numbers with all chlamydial strains. interestingly, the use of iscove's modified dulbecco's medium instead of eagle's minimal essential medium significantly increased chlamydia suis inc ...200415158211
respiratory chlamydial infection based on experimental aerosol challenge of pigs with chlamydia suis.an experimental study of aerogeneous challenge in pigs was conducted in order to reveal characteristic features of porcine respiratory chlamydiosis. eight conventionally raised pigs were exposed to a pathogenic strain of chlamydia (c.) suis, four controls were mock infected. besides pathological changes, the acute-phase and humoral immune responses, as well as the dissemination and transmission of the challenge strain was monitored in the course of infection. the data from clinical investigation ...200414656538
diagnostic investigation into the role of chlamydiae in cases of increased rates of return to oestrus in pigs.cervical swabs and serum samples were taken from swiss herds of sows with high rates of irregular return to oestrus (group a) and from control herds without reproductive problems (group b. the genital tracts of 21 slaughtered sows of group a were also examined. the swabs and genital tracts were screened for chlamydiae by a new 16s rrna pcr and the sera by an elisa for chlamydiaceae lipopolysaccharide. chlamydophila (cp) abortus was isolated from seven of the 65 swabs taken from group a but from ...200415573952
occurrence of chlamydiaceae spp. in a wild boar (sus scrofa l.) population in thuringia (germany).tissue samples from lungs, pulmonary lymph nodes, large intestine, and uteri of 14 wild boar bagged at a seasonal hunt were examined for the presence of chlamydiae, mycobacteria and mycoplasmas. nested pcr detected chlamydial dna in 57.1% of the animals, predominantly in the lung. dna sequencing identified chlamydophila psittaci as the predominant species, but chlamydophila abortus and chlamydia suis were also encountered. immunohistochemical staining of tissue sections confirmed the presence of ...200415381275
recombinant major outer membrane protein (momp) of chlamydophila abortus, chlamydophila pecorum, and chlamydia suis as antigens to distinguish chlamydial species-specific antibodies in animal sera.recombinant major outer membrane proteins (rmomp) of chlamydophila (ch.) abortus, ch. pecorum, and chlamydia (c.) suis were used as antigens to distinguish chlamydial species-specific antibodies in (i) immune sera from six rabbits and three pigs raised against native purified elementary bodies, (ii) serum samples from 25 sows vaccinated with ch. abortus, and (iii) 40 serum samples from four heifers experimentally infected with ch. abortus. all post-exposition sera contained chlamydial antibodies ...200415381270
tetracycline resistance in chlamydia suis mediated by genomic islands inserted into the chlamydial inv-like gene.many strains of chlamydia suis, a pathogen of pigs, express a stable tetracycline resistance phenotype. we demonstrate that this resistance pattern is associated with a resistance gene, tet(c), in the chlamydial chromosome. four related genomic islands were identified in seven tetracycline-resistant c. suis strains. all resistant isolates carry the structural gene tet(c) and the tetracycline repressor gene tetr(c). the islands share significant nucleotide sequence identity with resistance plasmi ...200415388463
[an enzyme-linked immunosorbent assay (elisa) for the detection of anti-chlamydial antibodies in pig sera].the evaluation of an enzyme-linked immunosorbent assay (elisa) for the detection of antibodies against chlamydiae in pig sera is described. the most widely used serological test is the complement fixation test (cft). the cft has a lack of sensitivity and specificity because of low antibody titers and unspecific reactions. eight conventionally raised pigs were exposed to a pathogenic strain of chlamydia suis, four controls were mock infected. the immune responses was monitored by cft and indirect ...200515690631
a new amplification target for pcr-rflp detection and identification of chlamydiaceae species.the family chlamydiaceae contains nine species pathogenic to humans and animals, but their routine identification is hampered by inadequate detection methods. in an attempt to find a new region for pcr detection and discrimination of the chlamydiaceae species, the 3' end of the omp2 gene of chlamydiaceae has been examined. since sequence data for this part of the genes of chlamydophila felis and chlamydia suis had not been available, the near full length of the omp2 genes of these species were c ...200515682280
evaluation of lung function in pigs either experimentally or naturally infected with chlamydiaceae.this study evaluated the influence of chlamydial infections on lung function in conventionally raised pigs. eight pigs aged 39-44 days were included in an aerogeneous challenge model (4 were exposed to chlamydia suis; 4 served as controls). nineteen pigs aged 5-27 weeks without clinical symptoms (but partly pcr-positive for chlamydial species) were examined over 6 months. for lung function testing, impulse oscillometry was used. in total, all 27 pigs underwent 465 lung function tests. variables ...200515943072
evaluation of antimicrobial resistance and treatment failures for chlamydia trachomatis: a meeting report.each year, chlamydia trachomatis causes ~3 million new infections and results in more than 1 billion dollars in medical costs in the united states. repeat or persistent infection occurs in 10%-15% of women who are treated for c. trachomatis infection. however, the role played by antimicrobial resistance in c. trachomatis treatment failures or persistent infection is unclear. with researchers in the field, we reviewed current knowledge and available approaches for evaluating antimicrobial resista ...200515717267
prevalence of chlamydiae in boars and semen used for artificial insemination.although there are indications for venereal transmission of chlamydiae in pigs, direct diagnostic evidence on the presence of these bacteria in boars and boar semen in particular is still incomplete. we investigated boars from two studs (a, b) in semen (a: n = 174; b: n = 100) and faeces (a: n = 174; b: n = 24) for chlamydiae using ompa-pcr and partial ompa gene sequencing. additionally, blood serum was examined for chlamydial antibodies using an indirect elisa (a: n = 171; b: n = 62). chlamydia ...200616280160
functional characterization of iscs605, an insertion element carried by tetracycline-resistant chlamydia suis.stable tetracycline resistance in chlamydia suis is mediated by a family of genomic islands [the tet(c) islands] that are integrated into the chlamydial chromosome. the tet(c) islands contain several plasmid-specific genes, the tet(c) resistance gene and, in most cases, a novel insertion element (iscs605) encoding two predicted transposases. the hypothesis that iscs605 mediated the integration of the tet(c) resistance islands into the c. suis genome was tested using a plasmid-based transposition ...200717185536
intensively kept pigs pre-disposed to chlamydial associated conjunctivitis.in the present study, ocular chlamydial infections in pigs that originate from two different farming systems were investigated. in particular, the aim was to test pigs with and without clinical ocular symptoms for the presence of chlamydiaceae and for linked infections with acanthamoebae spp. possibly acting as vectors for chlamydia or chlamydia-like organisms. in a total of 181 pigs, 102 from germany (ger), representing the intensively kept animals and 79 from switzerland (ch), which were kept ...200717650151
the chlamydial invasin-like protein gene conundrum.variants of an ilp (invasin-like protein) gene have been identified previously in chlamydia caviae and in chlamydia suis. the c. caviae ilp gene is interrupted by two frame shift mutations while the c. suis gene is intact. characterization of the ilp gene in c. caviae passaged minimally in vitro showed that the two frameshift mutations were present in the original isolates. the gentamicin protection assay was used to determine if e. coli bacteria expressing the intact c. suis ilp could adhere to ...200717533147
sensitivity of chlamydia suis to cathelicidin peptides.nine chlamydia suis isolates, obtained from pigs with conjunctivitis, were molecularly characterized by ompa sequencing and their in vitro susceptibility to six cathelicidin peptides (smap-29, bac-7, bmap-27, bmap-27, bmap-28, pg-1, ll-37) determined in cell culture. smap-29 was the most active peptide, reducing the intracellular inclusion number by > or =50% at a concentration of 10 microg/ml (3 microm) in six of the nine isolates tested. three molecularly identical isolates were insensitive at ...200717391870
prevalence of chlamydiae in semen and genital tracts of bulls, rams and bucks.chlamydiae infect male genital organs of ruminants. however, little is known about their prevalence. hence, we investigated fresh and cryopreserved semen (bulls: n=304; rams: n=78; bucks: n=44) by polymerase chain reaction (pcr), as well as genital organs (bulls: n=13; rams: n=10; bucks: n=6) by immunohistochemistry (ihc) and pcr. sera from bulls (n=104) and small ruminants (n=61) were tested by lps and rmomp (recombinant major outer membrane protein) elisa and competitive elisa (celisa), respec ...200716935325
chlamydiae in free-ranging and captive frogs in switzerland.a total of 210 frog samples originating either from a mass mortality (1991/1992) or from routine postmortem investigations of the years 1990 to 2004 were examined retrospectively for a possible involvement of chlamydiae. for a prevalence study of chlamydia in a selected swiss amphibian population, 403 samples from free-ranging rana temporaria were examined. histopathology, immunohistochemistry using a monoclonal antibody against chlamydial lipopolysaccharide, and a 16s rrna polymerase chain reac ...200717317791
an experimentally induced chlamydia suis infection in pigs results in severe lung function disorders and pulmonary inflammation.this study was aimed at evaluating the pathophysiology of pulmonary dysfunctions and inflammatory consequences of an acute respiratory chlamydial infection induced experimentally in conventionally raised pigs (aged 39-44 days). eight animals were exposed to chlamydia suis (c. suis) and four non-infected animals served as controls. the total observation period was from seven days before challenge to seven days post exposure. while non-infected control pigs did not exhibit any clinical symptoms, a ...200818298931
distribution and molecular characterization of tetracycline resistance in laribacter hongkongensis.laribacter hongkongensis is a newly discovered bacterium associated with gastroenteritis and found in freshwater fish. although isolates resistant to tetracycline have been described, their resistance mechanisms have not been studied.200818227089
tetracycline-resistant chlamydia suis isolates in italy. 200818723867
in vitro detection of neutralising antibodies to chlamydia suis in pig sera. 200919202171
horizontal transfer of tetracycline resistance among chlamydia spp. in vitro.there are no examples of stable tetracycline resistance in clinical strains of chlamydia trachomatis. however, the swine pathogen chlamydia suis is commonly tetracycline resistant, both in america and in europe. in tested u.s. strains, this resistance is mediated by a genomic island carrying a tet(c) allele. in the present study, the ability of c. suis to mobilize tet(c) into other chlamydial species was examined. differently antibiotic resistant strains of c. suis, c. trachomatis, and chlamydia ...200919687238
aberrant chlamydial developmental forms in the gastrointestinal tract of pigs spontaneously and experimentally infected with chlamydia suis.the phenomenon of persistence is well known from in vitro studies, where it is associated with the production of aberrant bodies, but its occurrence in vivo is less well documented. the objective of this study was to search for aberrant bodies in intestinal tissues from pigs, describe their ultrastructure, and investigate the suitability of immunohistochemical staining for chlamydial heat shock protein 60 (chsp60) to detect such forms. intestinal tissues derived from pigs naturally and experimen ...200918950970
experimental enteric infection of gnotobiotic piglets with chlamydia suis strain s45.enteric chlamydial infections of pigs with chlamydia (c.) suis are frequent and often subclinical. the enteric pathogenicity of c. suis strain s45 was investigated in gnotobiotic piglets. piglets from three litters (n=31) were inoculated with egg-grown chlamydiae at 2-3 days of age (n=17) or used as controls (n=14). they were observed for clinical signs, killed and necropsied sequentially at 2-13 days postinoculation (dpi). feces were collected daily and investigated with an elisa for chlamydial ...200918950966
natural cross chlamydial infection between livestock and free-living bird species.the study of cross-species pathogen transmission is essential to understanding the epizootiology and epidemiology of infectious diseases. avian chlamydiosis is a zoonotic disease whose effects have been mainly investigated in humans, poultry and pet birds. it has been suggested that wild bird species play an important role as reservoirs for this disease. during a comparative health status survey in common (falco tinnunculus) and lesser (falco naumanni) kestrel populations in spain, acute gammapa ...201020976071
chlamydiaceae in cattle: commensals, trigger organisms, or pathogens?epidemiological data indicate that infection of cattle with chlamydiae such as chlamydophila (c.) pecorum, c. abortus, c. psittaci and chlamydia suis, is ubiquitous with mixed infections occurring frequently. the apparent lack of association between infection and clinical disease has resulted in debate as to the pathogenic significance of these organisms, and their tendency to sub-clinical and/or persistent infection presents a challenge to the study of their potential effects. however, recent e ...201020980178
antibody-neutralizing activity against all urogenital chlamydia trachomatis serovars in chlamydia suis-infected pigs.it is known that neutralizing species-specific or serovar-specific antibodies are produced in response to chlamydial infection in humans and in some animal species. in a previous study, a strong in vitro neutralizing activity to chlamydia suis in 80% of sera from c. suis-infected pigs had been observed. in view of the close relationship between c. suis and chlamydia trachomatis, in the present study, the neutralizing activity against d-k c. trachomatis and c. suis purified elementary bodies (ebs ...201021214636
possible pathogenic interplay between chlamydia suis, chlamydophila abortus and pcv-2 on a pig production farm.a concurrent outbreak of chlamydial disease in boars, sows and gilts and postweaning multisystemic wasting syndrome (pmws) in weaned piglets was investigated on a large pig production farm in estonia. chlamydia suis dna was detected in conjunctival swabs from boars, sows and gilts, but also in the faeces of boars and sows. chlamydophila abortus dna was found in semen, and in conjunctival swabs from sows; dna was demonstrated by microarrays. serum samples from boars were examined using a chlamydi ...201020228367
antibiotic resistance in chlamydiae.there are few documented reports of antibiotic resistance in chlamydia and no examples of natural and stable antibiotic resistance in strains collected from humans. while there are several reports of clinical isolates exhibiting resistance to antibiotics, these strains either lost their resistance phenotype in vitro, or lost viability altogether. differences in procedures for chlamydial culture in the laboratory, low recovery rates of clinical isolates and the unknown significance of heterotypic ...201020860486
characterisation of acid-base abnormalities in pigs experimentally infected with chlamydia suis.this study characterises the acid-base abnormalities in pigs experimentally infected with chlamydia suis (henderson-hasselbalch equation and constable's simplified strong ion equation). eight pigs were challenged with the respiratory pathogen c. suis and four pigs served as non-infected controls. pigs were monitored from 7 days before challenge to 8 days post-inoculation. clinical examination was performed twice daily and venous blood samples were collected every two days. blood-gas analysis, ha ...201019286403
in vitro activity of rifaximin against chlamydia suis. 201121979443
recurrence of chlamydiasuis infection in pigs after short-term antimicrobial treatment.the effect of short-term antimicrobial treatment on natural excretion of chlamydia suis in rectal swabs and c. suis and chlamydophila psittaci in nasal swabs was investigated in 47 clinically normal piglets by quantitative real-time pcr. pigs were treated im with 4 mg/kg enrofloxacin for 5 days (n = 22) or 2.5mg/kg enrofloxacin for 3 days followed by 100mg/ml tiamulin (n = 25). antimicrobial treatment reduced the number of pigs positive for chlamydiae and the quantity of chlamydial dna in positi ...201120800518
seroepidemiologic survey for chlamydia suis in wild boar (sus scrofa) populations in italy.we used serology to estimate the prevalence of exposure to chlamydiae in italian populations of wild boars (sus scrofa). sera from 173 hunter-killed wild boars harvested during the 2006-2009 hunting seasons in three italian regions were tested for antibodies to chlamydia suis, chlamydophila pecorum, chlamydophila abortus, and chlamydophila psittaci by the microimmunofluorescence test. antibody titers to chlamydiae ôëñ 1:32 were detected in 110 of the 173 samples tested (63.6%). specific reactivi ...201121719838
selection for tetracycline-resistant chlamydia suis in treated pigs.the aim of this study was to investigate chlamydia suis in a pig farm with an outbreak of conjunctivitis and diarrhea. eye swabs and pooled fecal samples were investigated for the presence of c. suis by real-time pcr and arraytube microarray. samples positive for c. suis by arraytube microarray assay were further tested for the presence of the tet(c) resistance gene by pcr. in the first examination, c. suis was identified in 12 six-week-old pigs showing conjunctivitis. of these, the tet(c) gene- ...201122036200
a nested multiplex polymerase chain reaction assay for the differential identification of three zooanthroponotic chlamydial strains in porcine swab samples.porcine chlamydial infection is an enzootic infectious disease caused by multiple members of the family chlamydiaceae (e.g. chlamydophila abortus, chlamydia suis, and chlamydophila pneumoniae). rapid and accurate differentiation of these pathogens is critical in the control and prevention of disease. the aim of the current study was to develop a nested multiplex polymerase chain reaction (nmpcr) assay to simultaneously detect the 3 chlamydial pathogens in clinical samples. in the first round of ...201121908308
waddlia, parachlamydia and chlamydiaceae in bovine abortion.the etiology remains unknown in many cases of bovine abortion in switzerland. bacteria of the chlamydiales order are known abortive agents, therefore cases of bovine abortion from three representative regions of switzerland were investigated in this study. particularly chlamydiaceae as well as the chlamydia-like organisms waddlia and parachlamydia were of interest, especially because of their possible zoonotic potential. placenta samples (n=343) were tested for these bacteria by different pcr-me ...201121658867
chlamydiaceae infections in pig.abstract: chlamydiaceae are gram-negative obligate intracellular bacteria. they are responsible for a broad range of diseases in animals and humans. in pigs, chlamydia suis, chlamydia abortus, chlamydia pecorum and chlamydia psittaci have been isolated. chlamydiaceae infections in pigs are associated with different pathologies such as conjunctivitis, pneumonia, pericarditis, polyarthritis, polyserositis, pseudo-membranous or necrotizing enteritis, periparturient dysgalactiae syndrome, vaginal di ...201121314912
the occurrence of chlamydia spp. in pigs with and without clinical disease.within the genera chlamydia, the development of refined diagnostic techniques has allowed the identification of four species that are capable of infecting pigs. the epidemiology, clinical, and zoonotic impacts of these species are however largely unknown. the study aimed to investigate the presence of chlamydia spp. in the intestines of growing pigs and in conjunctival swabs from finisher pigs, and relate the findings to clinical signs.201222280482
chlamydiosis: seroepidemiologic survey in a red deer (cervus elaphus) population in italy.chlamydiae are obligate, intracellular, gram-negative bacteria that are responsible for important diseases in humans, other mammals, and birds. studies have shown that chlamydiae could be present in wild ruminants, but the serodiagnostic method most commonly used did not allow identification of chlamydial species. we determined the prevalence of antibodies to chlamydia pecorum, chlamydia suis, chlamydia abortus, and chlamydia psittaci in 271 red deer (cervus elaphus) of a central italian populat ...201222493128
serological and nested pcr survey to determine the occurrence of chlamydia infections in the polish cattle population.chlamydia spp. is an obligate intracellular agent that causes chlamydiosis in animals and humans. the aim of the presented study was to investigate the prevalence of chlamydia infection in the polish cattle population, both asymptomatic and having reproductive disorders. the study was performed on 4,475 serum samples collected from 16 polish provinces at the turn of 2009-2011. the samples (3,419 from asymptomatic cattle and 1,056 from cattle with reproductive disorders) were tested by complement ...201324364434
evidence for chlamydiaceae and parachlamydiaceae in a wild boar (sus scrofa) population in italy.conjunctival swabs from 44 free-living wild boars culled during a demographic control programme applied in a regional park located in the northern italy were examined by 16s rrna encoding gene nested pcr. in total, 22 (50%) wild boars were pcr positive. sequencing of the amplicons identified chlamydia suis and chlamydia pecorum in 12 and 5 samples, respectively. for one sample found pcr positive, the nucleotide sequence could not be determined. four conjunctival samples showed ≥ 92% sequence sim ...201323564593
host defense peptides: general overview and an update on their activity against chlamydia spp.chlamydiae are obligate intracellular bacteria that cause serious diseases in a wide range of hosts. chlamydia trachomatis is one of the leading sexually transmitted pathogens in the world. because vaccines are not currently available, effective drugs are essential. in both animals and humans, chlamydial infections are often treated with tetracycline or its derivatives. a stable tetracycline-resistant phenotype was described in chlamydia suis strains from pigs in the usa and in europe. in humans ...201324111488
ocular lesions associated with chlamydia suis in a wild boar piglet (sus scrofa) from a semi-free range population in spain.the role of the wild boar (sus scrofa) as a reservoir for a large number of pathogens that can affect both domestic animals and humans has been widely studied in the last few years. however, the impact of some of these pathogens on the health of wild boar populations is still being determined. this article presents a clinical case of severe bilateral keratoconjunctivitis affecting a 2-mo-old piglet from a semi-free range population in spain. histopathologic and microbiologic analysis revealed le ...201323505718
tetracycline-resistant chlamydia suis in cases of reproductive failure on belgian, cypriote and israeli pig production farms.similar cases of severe reproductive failure associated with the presence of chlamydia suis in two belgian, one cypriote and one israeli pig farrowing to slaughter farms are presented. vaginal and rectal swabs from 39 sows were examined by culture and dna microarray. nineteen of 23 (83 %) c. suis-positive sows were infected with tetracycline-resistant c. suis strains, as determined by mic tests. furthermore, boar semen from a german artificial insemination centre, intended for export, was positi ...201323105027
evaluation of the presence and zoonotic transmission of chlamydia suis in a pig slaughterhouse.a significant number of studies on pig farms and wild boars worldwide, demonstrate the endemic presence of chlamydia suis in pigs. however, the zoonotic potential of this pathogen, phylogenetically closely related to chlamydia trachomatis, is still uninvestigated. therefore, this study aims to examine the zoonotic transmission in a belgian pig abattoir.201425358497
the immune response against chlamydia suis genital tract infection partially protects against re-infection.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 throu ...201425252649
novel locked nucleic acid (lna)-based probe for the rapid identification of chlamydia suis using real-time pcr.as the importance of chlamydial infections in pigs has become more obvious, a rapid and sensitive method to study the prevalence of chlamydia suis in pig herds is required. such a method should permit routine diagnostic tests for herds with clinical and subclinical infections, without the need for chlamydia culture.201425249439
evidence of a conserved role for chlamydia htra in the replication phase of the chlamydial developmental cycle.identification of the htra inhibitor jo146 previously enabled us to demonstrate an essential function for htra during the mid-replicative phase of the chlamydia trachomatis developmental cycle. here we extend our investigations to other members of the chlamydia genus. c. trachomatis isolates with distinct replicative phase growth kinetics showed significant loss of viable infectious progeny after htra was inhibited during the replicative phase. mid-replicative phase addition of jo146 was also si ...201425066238
development and validation of a real-time pcr for chlamydia suis diagnosis in swine and humans.pigs are the natural host for chlamydia suis, a pathogen which is phylogenetically highly related to the human pathogen c. trachomatis. chlamydia suis infections are generally treated with tetracyclines. in 1998, tetracyline resistant c. suis strains emerged on u.s. pig farms and they are currently present in the belgian, cypriote, german, israeli, italian and swiss pig industry. infections with tetracycline resistant c. suis strains are mainly associated with severe reproductive failure leading ...201424816542
genome sequence of chlamydia suis md56, isolated from the conjunctiva of a weaned piglet.chlamydia suis is a natural pathogen of pigs (sus scrofa) and causes conjunctivitis, pneumonia, enteritis, and various reproductive disorders that adversely impact this economically important animal. here, we report the first c. suis genome, that of c. suis md56, isolated from a conjunctival swab of a weaned piglet.201424812227
rare events of intragenus and intraspecies horizontal transfer of the 16s rrna gene.horizontal gene transfer (hgt) of operational genes has been widely reported in prokaryotic organisms. however, informational genes such as those involved in transcription and translation processes are very difficult to be horizontally transferred, as described by woese's complexity hypothesis. here, we analyzed all of the completed prokaryotic genome sequences (2,143 genomes) in the ncbi (national center for biotechnology information) database, scanned for genomes with high intragenomic heterog ...201526220935
assessment of chlamydia suis infection in pig farmers.chlamydia suis infections are endemic in domestic pigs in europe and can lead to conjunctivitis, pneumonia, enteritis and reproductive failure. currently, the knowledge on the zoonotic potential of c. suis is limited. moreover, the last decades, porcine tetracycline resistant c. suis strains have been isolated, which interfere with treatment of chlamydial infections. in this study, the presence of c. suis was examined on nine belgian pig farms, using chlamydia culture and a c. suis specific real ...201526576707
porcine retinal cell line vido r1 and chlamydia suis to modelize ocular chlamydiosis.human ocular chlamydia trachomatis infections can lead to trachoma, the major cause of infectious blindness worldwide. trachoma control strategies are very helpful but logistically challenging, and a trachoma vaccine is needed but not available. pigs are a valuable large animal model for various immunological questions and could facilitate the study of human ocular chlamydial infections. in addition, a recent study identified the zoonotic potential of chlamydia suis, the natural pathogen of pigs ...201526103808
a mouse model for chlamydia suis genital infection.a mouse model for chlamydia suis genital infection was developed. ninety-nine mice were randomly divided into three groups and intravaginally inoculated with chlamydia: 45 mice (group 1) received c. suis purified elementary bodies (ebs), 27 (group 2) were inoculated with c. trachomatis genotype e ebs and 27 mice (group 3) with c. trachomatis genotype f ebs. additionally, 10 mice were used as a negative control. at seven days post-infection (dpi) secretory anti-c. suis iga were recovered from vag ...201525854004
prevalence of chlamydial infections in fattening pigs and their influencing factors.chlamydial infections in pigs are associated with respiratory disease, diarrhea, conjunctivitis and other pathologies. the aim of this study was to define the prevalence of chlamydiaceae in swiss fattening pigs by applying sensitive and specific detection methods and to correlate prior antibiotic treatment and farm related factors with differences in prevalence. conjunctival and fecal swabs were collected from 636 pigs in 29 swiss fattening pig farms with and without antibiotic treatment, at the ...201526619187
chlamydial infections in wildlife-conservation threats and/or reservoirs of 'spill-over' infections?members of the order chlamydiales are biphasic intracellular pathogens known to cause disease in both humans and animals. as we learn more about the genetic diversity of this group of pathogens, evidence is growing that these bacteria infect a broader range of animal hosts than previously thought. over 400 host species are now documented globally with the majority of these being wild animals. given the impact of chlamydial infections on humans and domesticated animals, the identification of memb ...201627939160
natural products for the treatment of chlamydiaceae infections.due to the global prevalence of chlamydiae, exploring studies of diverse antichlamydial compounds is important in the development of effective treatment strategies and global infectious disease management. chlamydiaceae is the most widely known bacterial family of the chlamydiae order. among the species in the family chlamydiaceae, chlamydia trachomatis and chlamydia pneumoniae cause common human diseases, while chlamydia abortus, chlamydia psittaci, and chlamydia suis represent zoonotic threats ...201627754466
an infectious pig model of crohn's disease.over the last several years, we have demonstrated that intestinal lymphangitis and lymphatic obstruction are fundamental lesions in crohn's disease, for which no therapy is currently available. there is an infectious enteritis of young pigs that offers an opportunity to understand how the lymphangitis of cd may have been initiated. the pathology of chlamydial enteritis was described earlier, from 1987 to 2009.201627542129
extended semen for artificial insemination in swine as a potential transmission mechanism for infectious chlamydia suis.although typically unnoticed, chlamydia infections in swine have been shown to be both widespread and may impact production characteristics and reproductive performance in swine. serum titers suggest chlamydia infection within boar studs is common, and infected boars are known to shed chlamydia in their ejaculates. although the transmission of viruses in chilled extended semen (es) is well established, the inclusion of antibiotics in commercially available extender is generally believed to limit ...201627087534
tetracycline susceptibility in chlamydia suis pig isolates.the aims of the present study were to assess the prevalence of chlamydia suis in an italian pig herd, determine the tetracycline susceptibility of c. suis isolates, and evaluate tet(c) and tetr(c) gene expression. conjunctival swabs from 20 pigs were tested for c. suis by real-time polymerase chain reaction, and 55% (11) were positive. c. suis was then isolated from 11 conjunctival swabs resampled from the same herd. all positive samples and isolates were positive for the tet(c) resistance gene. ...201626913523
flow cytometry as an improved method for the titration of chlamydiaceae and other intracellular bacteria.chlamydiaceae is a family of intracellular bacteria causing a range of diverse pathological outcomes. the most devastating human diseases are ocular infections with c. trachomatis leading to blindness and genital infections causing pelvic inflammatory disease with long-term sequelae including infertility and chronic pelvic pain. in order to enable the comparison of experiments between laboratories investigating host-chlamydia interactions, the infectious titer has to be determined. titer determi ...201626849001
selective pressure promotes tetracycline resistance of chlamydia suis in fattening pigs.in pigs, chlamydia suis has been associated with respiratory disease, diarrhea and conjunctivitis, but there is a high rate of inapparent c. suis infection found in the gastrointestinal tract of pigs. tetracycline resistance in c. suis has been described in the usa, italy, switzerland, belgium, cyprus and israel. tetracyclines are commonly used in pig production due to their broad-spectrum activity and relatively low cost. the aim of this study was to isolate clinical c. suis samples in cell cul ...201627893834
tetracycline selective pressure and homologous recombination shape the evolution of chlamydia suis: a recently identified zoonotic pathogen.species closely related to the human pathogen chlamydia trachomatis (ct) have recently been found to cause zoonotic infections, posing a public health threat especially in the case of tetracycline resistant chlamydia suis (cs) strains. these strains acquired a tet(c)-containing cassette via horizontal gene transfer (hgt). genomes of 11 cs strains from various tissues were sequenced to reconstruct evolutionary pathway(s) for tet(c) hgt. cs had the highest recombination rate of chlamydia species s ...201627576537
quantifying the growth of chlamydia suis in cell culture using high-content microscopy.the porcine pathogen chlamydia suis is widespread in pig farming. isolation of chlamydia suis in cell culture is crucial for the generation and characterization of new isolates. however, isolation of chlamydia suis strains from field samples is fastidious. therefore, we exploited high-content microscopy to quantify the growth of chlamydia suis strains in different cell lines. we found that the cell line yielding optimal propagation of chlamydia suis differed among isolates, and we identified cel ...201727862609
tet(c) gene transfer between chlamydia suis strains occurs by homologous recombination after co-infection: implications for spread of tetracycline-resistance among chlamydiaceae.chlamydia suis is a swine pathogen that has also recently been found to cause zoonotic infections of the human eye, pharynx, and gastrointestinal tract. many strains contain a tetracycline class c gene [tet(c)] cassette that confers tetracycline resistance. the cassette was likely originally acquired by horizontal gene transfer from a gram-negative donor after the introduction of tetracycline into animal feed in the 1950s. various research groups have described the capacity for different chlamyd ...201728223970
chlamydia suis and chlamydia trachomatis induce multifunctional cd4 t cells in pigs.chlamydia trachomatis infections are the most prominent bacterial sexually-transmitted disease world-wide and a lot of effort is put into the development of an effective vaccine. pigs have been shown to be a valuable animal model for c. trachomatis vaccine development. the aim of this study was to decipher the t-cell-mediated immune response to chlamydial infections including c. trachomatis and c. suis, the chlamydia species naturally infecting pigs with a demonstrated zoonotic potential. vagina ...201727894718
the chlamydia suis genome exhibits high levels of diversity, plasticity, and mobile antibiotic resistance: comparative genomics of a recent livestock cohort shows influence of treatment regimes.chlamydia suis is an endemic pig pathogen, belonging to a fascinating genus of obligate intracellular pathogens. of particular interest, this is the only chlamydial species to have naturally acquired genes encoding for tetracycline resistance. to date, the distribution and mobility of the tet-island are not well understood. our study focused on whole genome sequencing of 29 c. suis isolates from a recent porcine cohort within switzerland, combined with data from usa tetracycline-resistant isolat ...201728338777
involvement of multiple chlamydia suis genotypes in porcine conjunctivitis.chlamydia suis has been detected in numerous disease conditions of pigs, particularly in eye infections. this study examined recurring conjunctivitis cases in five commercial pig farms in japan. 40.5% of the cases were identified as chlamydia positive using impression cytology of ocular smears and a genus-specific direct fluorescent antibody. c. suis was detected in 59.5% of the samples using pcr tests targeting 16s-23s rrna intergenic spacer region (isr) and ompa gene. genetic analysis of pcr a ...201728345224
chlamydial antibiotic resistance and treatment failure in veterinary and human medicine.the chlamydiaceae are widespread pathogens of both humans and animals. chlamydia trachomatis infection causes blinding trachoma and reproductive complications in humans. chlamydia pneumoniae causes human respiratory tract infections and atypical pneumonia. chlamydia suis infection is associated with conjunctivitis, diarrhea, and failure to gain weight in domestic swine. chlamydial infections in humans and domesticated animals are generally controlled by antibiotic treatment-particularly macrolid ...201727218014
asymptomatic infections with highly polymorphic chlamydia suis are ubiquitous in pigs.chlamydia suis is an important, globally distributed, highly prevalent and diverse obligate intracellular pathogen infecting pigs. to investigate the prevalence and genetic diversity of c. suis in china, 2,137 nasal, conjunctival, and rectal swabs as well as whole blood and lung samples of pigs were collected in 19 regions from ten provinces of china in this study.201729191191
development of a chlamydia suis-specific antibody enzyme-linked immunosorbent assay based on the use of a b-cell epitope of the polymorphic membrane protein c.chlamydia suis infections lead to economic loss in the pork industry. chlamydia suis infections could be successfully treated with tetracyclines until the appearance of a tetracycline resistant phenotype, which was acquired via horizontal gene transfer of the tet(c) gene. given the importance of c. suis as a swine pathogen and as a recently emerged tetracycline resistant pathogen with zoonotic potential, our aim was to develop a sensitive c. suis-specific antibody elisa based on the polymorphic ...201829314736
Displaying items 1 - 80 of 80