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PubMed1983

Attachment and internalization of a Chlamydia trachomatis lymphogranuloma venereum strain by McCoy cells: kinetics of infectivity and effect of lectins and carbohydrates.

The kinetics of attachment and ingestion of Chlamydia trachomatis serotype L1 by monolayers of McCoy cells were studied by using a method that discriminated between attachment and uptake. When about 1% of the McCoy cells was infected, the proteinase K-resistant chlamydial fraction, regarded as ingested chlamydiae, reached a constant value after about 3 h of incubation at 37 degrees C. Uptake of chlamydiae at 4 degrees C could not be demonstrated. The attached and ingested chlamydial fractions were constant over an eightfold increase in chlamydial inoculum. Chitobiose and chitotriose, the di- and trisaccharides of N-acetyl-D-glucosamine, reduced the association of C. trachomatis serotype L1 with McCoy cells. Higher concentrations of chitobiose also selectively inhibited ingestion of chlamydiae. A corresponding effect of chitobiose was also observed on the number of chlamydial inclusions. Wheat germ agglutinin, specific for N-acetyl-D-glucosamine residues, reduced the association of chlamydiae when incubated at 4 degrees C, but not at 37 degrees C. A small inhibiting effect of concanavalin A on association of chlamydiae, but no effect of the corresponding carbohydrates, indicates a nonspecific effect on chlamydial attachment of this lectin. These results suggest that beta 1 leads to 4-linked oligomers of N-acetyl-D-glucosamine are important in the specificity of attachment of C. trachomatis to McCoy cells.

Carbohydrates↗
PubMed1990

Structural and antigenic analysis of Chlamydia pneumoniae.

Several isolates of Chlamydia pneumoniae were compared with each other and to Chlamydia trachomatis and Chlamydia psittaci by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblots. Protein profiles of the C. pneumoniae isolates appeared to be the same and were distinct from the other Chlamydia species. A 39.5-kilodalton (kDa) protein, similar in molecular weight to the major outer membrane proteins (MOMP) of C. trachomatis and C. psittaci, was found in the Sarkosyl-insoluble fraction, demonstrating its association with the outer membrane complex. In the outer membrane complex, the MOMP was shown to exist in disulfide-linked protein complexes. Electron microscopy of the Sarkosyl-extracted elementary bodies showed that the structural rigidity and pear-shaped morphology remained intact. Rabbit immune sera prepared against C. pneumoniae demonstrated immunoreactive proteins of 98-, 77-, 75-, 66-, 60-, 39.5-, 28-, and 17.5-kDa proteins. Cross-reactivity experiments revealed that most of the antigenic reactivities shared between C. psittaci and C. trachomatis extend to C. pneumoniae and that the 98-kDa protein recognition appeared to be C. pneumoniae specific. In contrast to the other Chlamydia spp., the recognition of the C. pneumoniae MOMP by homologous immune sera was weak and was cross-reactive with the MOMPs of the other Chlamydia species. These results suggest that the C. pneumoniae MOMP is less immunogenic and antigenically complex than are the MOMPs of C. trachomatis and C. psittaci.

Antibodies, Bacterial↗
PubMed1990

Developmental cycle-specific host-free RNA synthesis in Chlamydia spp.

The incorporation of radiolabeled GTP into RNA in host-free Chlamydia trachomatis serovar L2 organisms was investigated. The incorporation was partially inhibited by rifampin and dactinomycin and hydrolyzed by RNase. RNA made by host-free chlamydiae consisted mainly of species of fewer than 800 bases in size, although 16S and 23S species were noted by agarose-gel electrophoresis. The hybridization of radiolabeled host-free RNA to restriction fragments of the gene encoding the major outer membrane protein was analyzed; all regions of the gene were transcribed. The relative intensity of hybridization of host-free RNA made by chlamydiae isolated during the middle and late stages of the developmental cycle to the DNA of clones encoding gene products known to be made at these times in vivo indicated that the temporal patterns of host-free and in vivo transcription were similar. Radiolabeled RNA from 1- and 24-h host-free Chlamydia psittaci 6BC organisms hybridized to many of the same EcoRI and BamHI restriction fragments of C. psittaci genomic DNA, although some differences could be noted. When these RNAs were used to screen a partial C. psittaci genomic library in lambda gt11, plaques were identified that reacted mainly either with 1-h RNA or with 24-h RNA. Because RNA synthesized by host-free chlamydiae appears to be developmental cycle stage specific, transcripts made by host-free chlamydiae may be convenient probes that can be used to clone developmental stage-specific chlamydial genes.

Bacterial Outer Membrane Proteins↗
PubMed1990

Chlamydia trachomatis-host cell interactions: role of the chlamydial major outer membrane protein as an adhesin.

The major outer membrane protein (MOMP) of Chlamydia trachomatis is characterized by four symmetrically spaced variable domains (VDs I to IV) whose sequences vary among serotypes. The surface-exposed portions of these VDs contain contiguous sequences that are both serotyping determinants and in vivo target sites for neutralizing antibodies. Previous studies using surface proteolysis of C. trachomatis B implicated VDs II and IV of the MOMP of this serotype in the attachment of chlamydiae to host cells. In this study, we used monoclonal antibodies (MAbs) specific to antigenic determinants located in VDs II and IV of the MOMP of serotype B to further investigate the role of the MOMP in the attachment of chlamydiae to host cells. MABs specific to serotype- and subspecies-specific epitopes located in exposed VDs II and IV, respectively, neutralized chlamydial infectivity for hamster kidney cells by blocking chlamydial attachment. We radioiodinated these MAbs and used them to determine the number and topology of the surface-exposed VDs II and IV epitopes on chlamydial elementary bodies. VDs II and IV each comprised approximately 2.86 x 10(4) negatively charged sites and were in proximity on the chlamydial cell surface. These studies suggest that the MAbs blocked chlamydial attachment by inhibiting electrostatic interactions with host cells. We examined the effects of thermal inactivation on both chlamydial attachment and conformation of the MOMP. Heat-inactivated chlamydiae failed to attach to host cells and exhibited a conformational change in an inaccessible invariant hydrophobic nonapeptide sequence located within VD IV of the MOMPs of C. trachomatis serotypes. These findings suggest that in addition to electrostatic interactions, a common hydrophobic component of the MOMP also contributes to the binding of chlamydiae to host cells. Thus, we propose that the MOMP functions as a chlamydial adhesin by promoting nonspecific (electrostatic and hydrophobic) interactions with host cells. Surface-accessible negatively charged VDs appear to be important in electrostatic binding, while the invariant region of VD IV may provide a subsurface hydrophobic depression which further promotes binding of chlamydiae to host cells through hydrophobic interactions.

Antibodies, Monoclonal↗
PubMed1994

Abortion and subsequent excretion of chlamydiae from the reproductive tract of sheep during estrus.

Chlamydia psittaci serovar 1 infection in pregnant sheep typically causes abortion or the birth of weak lambs. Eight sheep that experienced chlamydia-induced abortion during their first pregnancy were successfully rebred yearly for the past 2 years. Chlamydia-specific lipopolysaccharide was detectable for approximately 3 weeks in vaginal swabs taken from the experimentally infected sheep following abortion. There was no evidence of chlamydiae in vaginal, placental, or neonatal samples obtained immediately after each subsequent successful pregnancy. Sera collected from the experimentally infected sheep had persistent, high antibody levels to C. psittaci, suggesting continued exposure of the immune system to the organism. Examination of vaginal specimens obtained during various stages of the estrus cycle revealed detectable levels of chlamydiae only when the animal was near ovulation. Chlamydiae were not detected in swabs from sheep that did not experience abortion. Enhanced chlamydial excretion during the periovulation period of sheep may provide sufficient stimulation of the immune system to account for the persistent antibody response. Furthermore, the association between estrus and chlamydial shedding has important implications for transmission of infection to other ewes during breeding.

Abortion, Veterinary↗
PubMed2004

Interaction of Chlamydia trachomatis serovar L2 with the host autophagic pathway.

Chlamydiae are obligate intracellular pathogens that replicate within a membrane-bound compartment (the inclusion) and are associated with important human diseases, such as trachoma, pneumonia, and atherosclerosis. We have examined the interaction of the host autophagic pathway with Chlamydia trachomatis serovar L2 by using the specific autophagosomal stain monodansylcadaverine, antibodies to autophagosome-associated markers, and traditionally used autophagic inhibitors, particularly 3-methyladenine and amino acids. Chlamydial inclusions did not sequester monodansylcadaverine, suggesting absence of fusion with autophagosomes. Interestingly, exposure of cultures infected for 19 h to 3-methyladenine or single amino acids until the end of infection (44 h) caused various degrees of abnormalities in the inclusion maturation and in the progeny infectivity. Incubation of host cells with chemicals throughout the entire period of infection modulated the growth of Chlamydia even more dramatically. Remarkably, autophagosomal markers MAP-LC3 and calreticulin were redistributed to the inclusion of Chlamydia, a process that appears to be sensitive to 3-methyladenine and some amino acids. The present data indicate the lack of autophagosomal fusion with the inclusion because it was devoid of monodansylcadaverine and no distinct rim of autophagosomal protein-specific staining around the inclusion could be observed. However, high sensitivity of Chlamydia to conditions that could inhibit host autophagic pathway and the close association of MAP-LC3 and calreticulin with the inclusion membrane still suggest a potential role of host autophagy in the pathogenesis of Chlamydia.

Adenine↗
PubMed2005

The Salmonella enterica serovar typhimurium-encoded type III secretion systems can translocate Chlamydia trachomatis proteins into the cytosol of host cells.

Chlamydia trachomatis is an obligate, intracellular pathogen that is a major cause of preventable blindness and infertility worldwide. Although the published genome sequence suggests that C. trachomatis encodes a type III secretion system, the lack of genetic tools for studying Chlamydia has hindered the examination of this potentially important class of virulence genes. We have developed a technique to identify Chlamydia proteins that can be translocated into the host cell cytoplasm by a type III secretion system. We have selected several Chlamydia proteins and tagged them with a multiple peptide motif element called F8M4. Epitopes contained in the F8M4 tag allow us to use tools corresponding to different arms of the adaptive immune system to detect the expression and translocation of these proteins by Salmonella enterica serovar Typhimurium. In particular, CD8(+)-T-cell reactivity can be used to detect the translocation of F8M4-tagged proteins into the cytoplasm of host cells. We have found that CD8(+)-T-cell activity assays are sensitive enough to detect translocation of even a small amount of F8M4-tagged protein. We have used CD8(+)-T-cell activity to show that CopN, a Chlamydia protein previously shown to be translocated by Yersinia type III secretion, can be translocated by the Salmonella pathogenicity island 1 (SPI-1) type III secretion system. Additionally, we demonstrate that CopD and Pkn5, two Chlamydia proteins hypothesized to be substrates of a type III secretion system, are translocated via the SPI-2 type III secretion system of serovar Typhimurium. The epitope tag system described here can be used more generally to examine the expression and subcellular compartmentalization of bacterial proteins deployed during the interaction of pathogens with mammalian cells.

Animals↗
PubMed2003

Functional and biochemical analysis of Chlamydia trachomatis MurC, an enzyme displaying UDP-N-acetylmuramate:amino acid ligase activity.

Chlamydiae are unusual obligate intracellular bacteria that cause serious infections in humans. Chlamydiae contain genes that appear to encode products with peptidoglycan biosynthetic activity. The organisms are also susceptible to antibiotics that inhibit peptidoglycan synthesis. However, chlamydiae do not synthesize detectable peptidoglycan. The paradox created by these observations is known as the chlamydial anomaly. The MurC enzyme of chlamydiae, which is synthesized as a bifunctional MurC-Ddl product, is expected to possess UDP-N-acetylmuramate (UDP-MurNAc):L-alanine ligase activity. In this paper we demonstrate that the MurC domain of the Chlamydia trachomatis bifunctional protein is functionally expressed in Escherichia coli, since it complements a conditional lethal E. coli mutant possessing a temperature-sensitive lesion in MurC. The recombinant MurC domain was overexpressed in and purified from E. coli. It displayed in vitro ATP-dependent UDP-MurNAc:L-alanine ligase activity, with a pH optimum of 8.0 and dependence upon magnesium ions (optimum concentration, 20 mM). Its substrate specificity was studied with three amino acids (L-alanine, L-serine, and glycine); comparable Vmax/Km values were obtained. Our results are consistent with the synthesis of a muramic acid-containing polymer in chlamydiae with UDP-MurNAc-pentapeptide as a precursor molecule. However, due to the lack of specificity of MurC activity in vitro, it is not obvious which amino acid is present in the first position of the pentapeptide.

Alanine↗
PubMed1997

Species identification of Chlamydia isolates by analyzing restriction fragment length polymorphism of the 16S-23S rRNA spacer region.

The genetic diversity of the 16S-23S rRNA spacer region of 12 Chlamydia pneumoniae isolates, 7 Chlamydia trachomatis isolates (human biovars: the trachoma serovars B and C, the urogenital serovars D, E, and F, and the lymphogranuloma venereum serovar L2; and a mouse biovar), 6 Chlamydia psittaci isolates (5 avian isolates and 1 feline isolate), and one Chlamydia pecorum isolate was studied. The 16S-23S rRNA spacer region was amplified by PCR and digested with the restriction enzymes MseI, PstI, AluI, BglII, NlaIV, and BclI. All 26 isolates could be amplified by using one genus-specific primer pair, yielding an amplicon with a size of 803 bp. The analytical sensitivity of the PCR assay was < or = 100 inclusion-forming units per reaction. Digestion with MseI or AluI made it possible to differentiate the four species from each other, the C. trachomatis human biovars from the mouse biovar, and the C. psittaci avian isolates from the feline isolate. The MseI profiles were more distinct than the AluI profiles. Phylogenetic analysis of the results for all enzymes combined supported the current classification of four Chlamydia species: C. pneumoniae, C. trachomatis, C. psittaci, and C. pecorum. Phylogenetic analysis also suggested subdivision of isolates of C. trachomatis and C. psittaci into subgroups that coincide with their host range. In conclusion, we have developed an easy and rapid method for species and subspecies identification of Chlamydia based on restriction fragment length polymorphism analysis of the 16S-23S rRNA spacer region.

Bacterial Typing Techniques↗
PubMed2005

Young, male, and infected: the forgotten victims of chlamydia in primary care.

OBJECTIVES: To identify current levels of testing men for chlamydia and establish levels of knowledge relating to chlamydia infection among practice nurses in primary care in one north Wales local area health group (LHG) as part of a study to improve delivery of sexual health services in primary care. METHODS: Anonymous confidential self completed postal questionnaires were sent to 46 practice nurses employed at 22 GP practices within one north Wales LHG. On return of the questionnaires and analysis of the data using SPSS, semistructured interviews with seven practice nurses were undertaken. RESULTS: Responses were obtained from 33/46 (71.7%) practice nurses. The majority, 30 (90.9%), do not examine male genitalia and 18 (54.5%) have never tested male patients for chlamydia infection. 28 (84.8%) practice nurses do not consider contact tracing as part of their role. CONCLUSIONS: Primary care has a pivotal part to play in reducing prevalence of chlamydia. The paucity of male testing for chlamydia and a lack of consistent uniform testing and contact tracing in primary care has implications for the prevalence and long term consequences of infection. There is scope to greatly increase male testing for chlamydia both for those presenting with signs and symptoms of infection and those asymptomatic. This cannot be achieved without both educational and financial support for practice nurses.

Adolescent↗
PubMed1983

A study of inactivation of Chlamydia trachomatis by normal human serum.

To assess the effect of human serum on the viability of Chlamydia trachomatis, organisms were mixed with unheated and heat inactivated homologous serum, and the numbers surviving after incubation at 37 degrees C for 1 hour were compared. With a pool of sera obtained from 12 donors, the number of chlamydiae surviving incubation in unheated serum was less than 1% of that surviving incubation in heat inactivated serum. The antichlamydial activity of the unheated pooled serum samples could be noticeably reduced by treatment with Mg-EGTA (ethyleneglycolbis (beta-amino ethyl ether)-N,N'-tetra-acetic acid). This indicated a requirement for calcium ions and showed that the alternative pathway of complement activation played only a minor role, if any, in the inactivation process. When 12 serum samples were tested individually it was found that four inactivated chlamydiae to an extent comparable with that seen with the pooled serum. The other eight samples showed only moderate (or slight) antichlamydial activity, with survival rates in unheated serum of 20-60% (or more than 60%) of those in heat inactivated serum. There was no correlation between the titres of antichlamydial antibodies and antichlamydial activity, all serum samples having undetectable or low concentrations of antibody on measurement by micro-immunofluorescence. The antichlamydial activity destroyed by heating was restored, however, when heat inactivated serum was mixed with an equal volume of an unheated serum that was not inhibitory to chlamydiae. When the latter serum was heated before addition antichlamydial activity was not restored, indicating the requirement of both a heat stable and a heat labile factor. This observation and the need for calcium ions for inactivation of chlamydiae are compatable with killing mediated by antibody and complement. Thus serum samples from individuals with no clinical or serological evidence of infection with chlamydiae vary in their ability to inactivate the organism, some having antichlamydial activity which is possibly mediated by antibody and complement.

Antibodies, Bacterial↗
PubMed1999

Do the factors associated with successful contact tracing of patients with gonorrhoea and Chlamydia differ?

OBJECTIVE: To assess and compare factors which may be associated with successful contact tracing in patients with gonorrhoea and chlamydia. STUDY DESIGN: Prospective observational study of patients attending a genitourinary medicine clinic with a diagnosis of gonorrhoea or chlamydia. Multivariate analysis model including demographic, socioeconomic, and behavioural variables. RESULTS: The attendance of at least one sexual contact was associated with naming more contacts for patients with gonorrhoea (OR 1.44, 95% CI 1.04-2.01). A history of gonorrhoea was associated with successful contact tracing for patients with chlamydia (OR 1.46, 95% CI 1.12-1.9). Successful contact tracing, as defined by at least one confirmed contact attendance after the index case, was not associated with age, sex, sexual orientation, history of chlamydia, use of condoms, marital status, ethnicity, or socioeconomic status for either gonorrhoea or chlamydia. CONCLUSIONS: Differences in the composition of the core groups infected with gonorrhoea and chlamydia are not explained by differences in contact tracing success. In the clinic setting studied, the outcome of contact tracing was not associated with a variety of demographic, socioeconomic, and behaviour factors.

Adult↗
PubMed1994

Self-esteem, problem solving, and sexual risk behavior among women with and without Chlamydia.

Self-esteem and problem-solving appraisal were evaluated as an explanation of sexual risk behavior for the sexually transmitted disease (STD), chlamydia. Chlamydia, the most prevalent bacterial STD in the United States, is linked to a variety of problems which affect women, their offspring, and their sex partners. Data were collected by two nurse practitioners during scheduled gynecology visits for 105 military women. There was a statistical association among women with chlamydia (chi 2 = 3.623, df = 1, p = .057) and trichomonas (chi 2 = 12.83, df = 1, p = < .001) and a friable cervix. With a 10% prevalence of chlamydia, accurate diagnosis and treatment are imperative. No differences between the prevalence of chlamydia and self-esteem and problem-solving appraisal were noted. These findings support the strategies for diagnoses, treatment, and prevention of chlamydia recommended by the Centers for Disease Control.

Adult↗
PubMed2006

Developing a realistic sexual network model of chlamydia transmission in Britain.

BACKGROUND: A national chlamydia screening programme is currently being rolled out in the UK and other countries. However, much of the epidemiology remains poorly understood. In this paper we present a stochastic, individual based, dynamic sexual network model of chlamydia transmission and its parameterisation. Mathematical models provide a theoretical framework for understanding the key epidemiological features of chlamydia: sexual behaviour, health care seeking and transmission dynamics. RESULTS: The model parameters were estimated either directly or by systematic fitting to a variety of appropriate data sources. The fitted model was representative of sexual behaviour, chlamydia epidemiology and health care use in England. We were able to recapture the observed age distribution of chlamydia prevalence. CONCLUSION: Estimating parameters for models of sexual behaviour and transmission of chlamydia is complex. Most of the parameter values are highly correlated, highly variable and there is little empirical evidence to inform estimates. We used a novel approach to estimate the rate of active treatment seeking, by combining data sources, which improved the credibility of the model results. The model structure is flexible and is broadly applicable to other developed world settings and provides a practical tool for public health decision makers.

Adolescent↗
PubMed2000

Coronary artery disease and infection with chlamydia pneumonia.

The association between chlamydia pneumonia and coronary artery disease is well documented, however less is known about the correlation between chlamydia pneumonia infection and blood inflammatory markers or lipid levels. In 100 patients with proven coronary artery disease (25 females, 61.0 +/- 4.0 years old), and 60 healthy volunteer control cases (15 females, 60.6 +/- 3.4 years old), anti chlamydia pneumonia IgG, blood lipid, C-reactive protein and fibrinogen levels were detected. In cases with coronary artery disease seropositivity for IgG antibodies to chlamydia pneumonia (74% versus 34%, p < 0.0001), C-reactive protein (mg / l) (2.8 +/- 0.6 versus 1.4 +/- 0.6; p < 0.0001), fibrinogen (mg / dl) (317.4 +/- 38.2 versus 256.2 +/- 34.5, p < 0.0001), triglyceride (mg / dl) (217.5 +/- 39.0 versus 191.0 +/- 25.9, p < 0.0001), LDL-cholesterol (mg / dl) (126.9 +/- 19.2 versus 110.6 +/- 19.5, p < 0.0001) levels and total cholesterol / HDL-cholesterol ratio (7.7 +/- 1.8 versus 4.4 +/- 1.2, p < 0.0001) were higher but the level of HDL-cholesterol (mg / dl) (26.4 +/- 6.7 versus 47.0 +/- 11.2, p < 0.0001) was lower. The levels of total cholesterol did not differ between the two groups (p=0.9). Levels of triglyceride (r=0.60, p < 0.00001), LDL-cholesterol (r = 0.27, p = 0.0004), C-reactive protein (r = 0.69, p < 0.00001), fibrinogen (r = 0.60, p < 0.00001) and total cholesterol / HDL-cholesterol ratio (r = 0.74, p < 0.00001) had a direct relation, but the level of HDL-cholesterol had a negative (r= -0.80, p < 0.00001) relation with the seropositivity for chlamydia pneumonia. As a result, seropositivity for IgG antibodies to chlamydia pneumonia is considered as a risk factor for coronary artery disease by its association with the atherogenic lipid profile and procoagulant activity.

Antibodies↗
PubMed2000

Testing for Chlamydia and sexual history taking in adolescent females: results from a statewide survey of Colorado primary care providers.

OBJECTIVES: Little is known about the practice patterns of primary care providers as they relate to assessing risk of and screening for chlamydial infections, an important cause of preventable reproductive morbidity in young women in the United States. The present cross-sectional study was undertaken to assess levels of chlamydia testing, sexual history taking, and prevention practices by Colorado primary care physicians, nurse practitioners, and physician assistants who provide gynecologic care to adolescent females (13-19 years old). METHODS: Between July 1998 and October 1998, an anonymous, self-administered questionnaire was mailed to a 25% random sample (n = 1265) of Colorado physicians (family practitioners, internal medicine specialists, obstetrician-gynecologists, and pediatricians), nurse practitioners, and physician assistants. Practitioners were identified through professional organization membership, state-licensing bodies, and listings in the yellow pages. RESULTS: After estimating the eligibility rate among non-respondents, the adjusted response rate was 71.5%. Only 53.8% of providers reported regularly testing sexually active female adolescents for chlamydia; 71.8% of providers regularly took a sexual history. Female providers reported significantly higher levels of regularly taking a sexual history (87. 2% vs 60.6% of males), feeling comfortable discussing sex (94.4% vs 77.8%), discussing sexually transmitted disease (STD) prevention (81. 5% vs 71.3%), and testing for chlamydia (64.4% vs 38.6%). Among provider types, obstetrician-gynecologists, nurse practitioners, and pediatricians were most likely to report regularly taking a sexual history (90.1%, 88.6%, and 76.0%, respectively). Internal medicine specialists were the least likely to report taking a sexual history (43.9%). Pediatricians and nurse practitioners were the most likely to report testing sexually active adolescent females for chlamydia (74.1% and 70.1%, respectively), whereas physician assistants and internal medicine specialists were the least likely (46.0% and 38.5%, respectively). In multivariate analysis, variables independently associated with regularly taking a sexual history included female provider gender (odds ratio [OR]: 5.5; 95% confidence interval [CI]: 2.9-10.9), obstetrics/gynecology specialty (OR: 4.0; 95% CI: 1.7-10. 3; referent group: family practitioners), and provider comfort level in discussing sex (OR: 4.9; 95% CI: 2.3-11.1). Variables independently associated with regularly testing adolescent females for chlamydia included female provider gender (OR: 2.8; 95% CI: 1. 6-4.8), regularly discussing STD prevention (OR: 2.1; 95% CI: 1.1-4. 1), and regularly discussing limiting the number of patients' sex partners (OR: 2.4; 95% CI: 1.4-4.1). CONCLUSIONS: Only a little over one half of providers (54%) reported regularly performing chlamydia tests on adolescent females who are sexually active by history. Because this falls well short of the recommendations of the Centers for Disease Control and Prevention to test all sexually active female adolescents, efforts are needed to improve STD clinical practices of Colorado physician and nonphysician providers of primary care for adolescent females. Particular efforts are needed to close the provider gender gap.

Adolescent↗
PubMed2000

Chlamydia pneumoniae and atherosclerosis. Identification of bacterial DNA in the arterial wall.

OBJECTIVE: The intracellular Gram-negative bacterium Chlamydia pneumoniae has been associated with atherosclerosis. The presence of Chlamydia pneumoniae has been investigated in fragments of the arterial wall with a technique for DNA identification. METHODS: Arterial fragments obtained from vascular surgical procedures in 58 patients were analyzed. From these patients, 39 were males and the mean age was 65+/-6 years. The polymerase chain reaction was used to identify the bacterial DNA with a pair of primers that codify the major outer membrane protein (MOMP) of Chlamydia pneumoniae. The amplified product was visualized by electrophoresis in the 2% agarose gel stained with ethidium bromide, and it was considered positive when migrating in the band of molecular weight of the positive controls. RESULTS: Seven (12%) out of the 58 patients showed positive results for Chlamydia pneumoniae. CONCLUSION: DNA from Chlamydia pneumoniae was identified in the arterial wall of a substantial number of patients with atherosclerosis. This association, which has already been described in other countries, corroborates the evidence favoring a role played by Chlamydia pneumoniae in atherogenesis.

Aged↗
PubMed1996

Serology of chlamydia in relation to asthma and bronchial hyperresponsiveness.

Antibodies to the 3 strains of chlamydia were measured in the sera of 197 subjects; 122 with asthma-related symptoms and 75 from the general population. The subjects underwent a structured interview, spirometry, a methacholine provocation test and skin-prick tests. For chlamydia antibodies, IgG titer values of > or = 1:512 and/or IgM > or = 1:16 were regarded as evidence of a current or recent infection while IgG levels < 1:512 and > 1:32 were regarded as indicative of a previous infection. For Chlamydia pneumoniae, a relationship was found between current or recent infection and wheezing (odds ratio (OR) 6.0, confidence intervals (CI) 1.3-28) and also between IgA antibodies and bronchial hyperresponsiveness (BHR) (OR 3.3, CI 1.3-8.3). For Chlamydia trachomatis, serological signs of a previous infection were found significantly more often in subjects who reported having had asthma at some time: (OR 3.2, CI 1.4-7.1), asthma during the last year (OR 3.2, CI 1.4-7.1), wheezing during the last year (OR 4.2, CI 1.6-6.6) and in those who had BHR (OR 2.7, CI 1.2-6.1). We conclude that a relationship may exist between Chlamydia pneumoniae and Chlamydia trachomatis infections and asthma-related symptoms and BHR.

Adult↗