is the leading cause of sexually transmitted infections that may progress to pelvic inflammatory disease and infertility. No effective vaccine exists for , nor are there biomarkers available that readily predict disease progression. In this cross-sectional pilot study, we recruited symptomatic and asymptomatic women with (CT) infection and asymptomatic, uninfected control women from an urban sexually transmitted disease clinic to determine if there were differences in microRNA (miRNA) expression.
View Article and Find Full Text PDFPurpose: Evidence has shown an inverse correlation between previous dental care experience and anxiety levels in children. This study aimed to determine the prevalence of dental anxiety in Brazilian schoolchildren and to evaluate the association between previous experience with the dentist and anxiety and fear of pain.
Methods: This was a cross-sectional descriptive study carried out in two cities in Brazil with 1191 schoolchildren aged 6-12 years.
Aims: To verify the effect of awards after dental care in children's motivation in two visits to the dentist and if differences occur between genders.
Methods: This was a randomised and blinded study with a systematic convenience sample consisting of 306 children of 4.99 ± 0.
Chlamydia muridarum and Chlamydia caviae have equivalent growth rates in mouse epithelial cells but only C. muridarum replicates inside mouse macrophages, while C. caviae does not.
View Article and Find Full Text PDFObjective: To assess the efficacy of the Baby's Mouth early dental care prevention and promotion program in preventing oral diseases (caries, gingivitis, or malocclusions) in children attended since 2010.
Methods: This was a cross-sectional and cohort study that assessed 252 children between 36 and 60 months of age in both sexes. The children were divided into three groups: G1: effective participants of the program from birth; G2: children who have stopped participating for more than 24 months, and G3: children who have never attended a prevention program.
Not all women infected with chlamydiae develop upper genital tract disease, but the reason(s) for this remains undefined. Host genetics and hormonal changes associated with the menstrual cycle are possible explanations for variable infection outcomes. It is also possible that disease severity depends on the virulence of the chlamydial inoculum.
View Article and Find Full Text PDFBackground: Breastfeeding is associated with a variety of positive health outcomes in children and is recommended exclusively for the first 6 months of life; however, 50-70 % of infants in the US are formula-fed. To test the hypothesis that immune system development and function in neonates and infants are significantly influenced by diet, 2-day old piglets were fed soy or milk formula (n = 6/group/gender) until day 21 and compared to a sow-fed group (n = 6/gender).
Methods: Histomorphometric analyses of ileum, jejunum and Peyer's patches were carried out, to determine the inflammation status, mRNA and protein expression of pro-inflammatory, anti-inflammatory and growth-related chemokines and cytokines.
An important question in the study of chlamydial genital tract disease is why some women develop severe upper tract disease while others have mild or even "silent" infections with or without pathology. Animal studies suggest that the pathological outcome of an infection is dependent upon both the composition of the infecting chlamydial population and the genotype of the host, along with host physiological effects, such as the cyclical production of reproductive hormones and even the size of the infecting inoculum or the number of repeated infections. In this study, we compared two variants of Chlamydia caviae, contrasting in virulence, with respect to their abilities to ascend the guinea pig genital tract.
View Article and Find Full Text PDFBackground: Single-dose azithromycin is recommended over multi-dose doxycycline as treatment for chlamydial infection. However, even with imperfect adherence, doxycycline is more effective in treating genital and rectal infection. Recently, it has been suggested that autoinoculation from the rectum to the genitals may be a source of persistent chlamydial infection in women.
View Article and Find Full Text PDFIn humans, the vaginal microbiota is thought to be the first line of defense again pathogens including Chlamydia trachomatis. The guinea pig has been extensively used as a model to study chlamydial infection because it shares anatomical and physiological similarities with humans, such as a squamous vaginal epithelium as well as some of the long-term outcomes caused by chlamydial infection. In this study, we aimed to evaluate the guinea pig-C.
View Article and Find Full Text PDFWe have previously shown that Chlamydia muridarum has multiple genomic variants that concomitantly vary in their in vitro and in vivo phenotype. Herein, we used real-time polymerase chain reaction-based genotyping assays to query plaque-cloned isolates of C. muridarum for the frequency of eight selected polymorphisms.
View Article and Find Full Text PDFGuinea pigs have been used as a second animal model to validate putative anti-chlamydial vaccine candidates tested in mice. However, the lack of guinea pig-specific reagents has limited the utility of this animal model in Chlamydia sp. vaccine studies.
View Article and Find Full Text PDFThe interactions between chlamydial pathogens and their host contribute to the outcome of infection. Nonresolving infections in immunodeficient mice can provide insights into these mechanisms by allowing observation of a form of persistent infection. Using a mathematical model, we predict that in a nonresolving infection, the number of chlamydiae in the host will attain a stable equilibrium and that this equilibrium will be independent of the inoculum size.
View Article and Find Full Text PDFUnlabelled: It is not currently possible to predict the probability of whether a woman with a chlamydial genital infection will develop pelvic inflammatory disease (PID). To determine if specific biomarkers may be associated with distinct chlamydial pathotypes, we utilized two Chlamydia muridarum variants (C. muridarum Var001 [CmVar001] and CmVar004) that differ in their abilities to elicit upper genital tract pathology in a mouse model.
View Article and Find Full Text PDFBackground: Sexually-transmitted pathogens often have severe reproductive health implications if treatment is delayed or absent, especially in females. The complex processes of disease progression, namely replication and ascension of the infection through the genital tract, span both extracellular and intracellular physiological scales, and in females can vary over the distinct phases of the menstrual cycle. The complexity of these processes, coupled with the common impossibility of obtaining comprehensive and sequential clinical data from individual human patients, makes mathematical and computational modelling valuable tools in developing our understanding of the infection, with a view to identifying new interventions.
View Article and Find Full Text PDFAlthough the concept of persistence in chlamydial infections has been recognized for about 80 years, there is still very little known about the mechanism by which this occurs. In this review, we revisit an old paradigm, long known to chlamydiologists and veterinarians, that in virtually all hosts of chlamydiae, including mammals and birds, chlamydiae reside in the gastrointestinal tract for long periods of time in the absence of clinical disease. Thus, if gastrointestinal infection occurs in most hosts, then it is very likely that gastrointestinal infection occurs in humans as well.
View Article and Find Full Text PDFAntimicrob Agents Chemother
December 2013
Evidence from animal studies suggests that chlamydiae may persist in the gastrointestinal tract (GI) and be a reservoir for reinfection of the genital tract. We hypothesize that there may be a differential susceptibility of organisms in the GI and genital tracts. To determine the effect of azithromycin on persistent chlamydial gut infection, C57BL/6 and BALB/c mice were infected orally and genitally and treated with azithromycin (Az) orally (20, 40, or 80 mg/kg of body weight), and the numbers of chlamydiae were determined from cervix and cecal tissues.
View Article and Find Full Text PDFAmong chlamydial virulence factors are the type III secretion (T3S) system and its effectors. T3S effectors target host proteins to benefit the infecting chlamydiae. The assortment of effectors, each with a unique function, varies between species.
View Article and Find Full Text PDFThe mechanism by which chlamydiae persist in vivo remains undefined; however, chlamydiae in most animals persist in the gastrointestinal tract (GI) and are transmitted via the fecal-oral route. Oral infection of mice with Chlamydia muridarum was previously shown to establish a long-term persistent infection in the GI tract. In this study, BALB/c, DBA/2, and C57Bl/6 mice, infected orally with C.
View Article and Find Full Text PDFIn order to study the interaction of variants in in vivo infection, we employed an azithromycin-resistant mutant (AZ(2)) and its wild-type parent (SP(6)) in the guinea pig model of Chlamydia caviae conjunctival infection. When each strain was inoculated individually into conjunctiva, both attained the same level of growth, but AZ(2) elicited less pathology. However, when equal numbers of the two strains were inoculated together into the guinea pig conjunctiva, SP(6) produced a significantly greater number of inclusion-forming units than AZ(2), and the pathology reflected that of a SP(6) monoinfection.
View Article and Find Full Text PDFWe utilized a recently developed model of intracervical infection with Chlamydia muridarum in the mouse to elicit a relatively synchronous infection during the initial developmental cycle in order to examine at the ultrastructural level the development of both the chlamydial inclusion and the onset of the inflammatory response. At 18 h after infection, only a few elementary bodies attached to cells were visible, as were an occasional intracellular intermediate body and reticulate body. By 24 h, inclusions had 2 to 5 reticulate bodies and were beginning to fuse.
View Article and Find Full Text PDFLate Chlamydia trachomatis inclusions express each member of the surface-exposed polymorphic membrane protein family (Pmp subtypes A through I) with a reproducible distribution of fully-on, fully-off and intermediate phenotypes. This observation is consistent with observed variable Pmp antibody profiles in C. trachomatis-infected patients and has led to the hypothesis that the pmp gene family forms the basis of a phase variation-like mechanism of antigenic variation.
View Article and Find Full Text PDFTrachoma, the world's leading cause of preventable blindness, is produced by chronic ocular infection with Chlamydia trachomatis, an obligate intracellular bacterium. While many studies have focused on immune mechanisms for trachoma during chronic stages of infection, less research has targeted immune mechanisms in primary ocular infections, events that could impact chronic responses. The goal of this study was to investigate the function of neutrophils during primary chlamydial ocular infection by using the guinea pig model of Chlamydia caviae inclusion conjunctivitis.
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