Regulation of chlamydial infection by host autophagy and vacuolar ATPase-bearing organelles

As arguably the most successful parasite, Chlamydia is an obligate intracellular bacterium replicating inside a vacuole of eukaryotic host cells. The chlamydial vacuole does not fuse with the defense cell organelle lysosome. We previously showed that chlamydial infection increases markers of autophagy, an innate antimicrobial activity requiring lysosomal function. However, the work presented here demonstrates that p62, an autophagy protein that is degraded in lysosomes, either remained unchanged or increased in chlamydia-infected human epithelial, mouse fibroblast, and mouse macrophage cell lines. In addition, the activities of three lysosomal enzymes analyzed were diminished in chlamydia-infected macrophages. Bafilomycin A1 (BafA), a specific inhibitor of vacuolar ATPase (vATPase) required for lysosomal function, increased the growth of the human pathogen Chlamydia trachomatis (L2) in wild-type murine fibroblasts and macrophages but inhibited growth in the autophagy-deficient ATG5(-/-) fibroblasts. BafA exhibited only slight inhibition or no effect on L2 growth in multiple human genital epithelial cell lines. In contrast to L2, the mouse pathogen Chlamydia muridarum (MoPn) was consistently inhibited by BafA in all cell lines examined, regardless of species origin and autophagy status. Finally, L2 but not MoPn grew more efficiently in the ATG5(-/-) cells than in wild-type cells. These results suggest that there are two types of vATPase-bearing organelles that regulate chlamydial infection: one supports chlamydial infection, while the other plays a defensive role through autophagy when cells are artificially infected with certain chlamydiae that have not been adapted to the host species.

Targeting of a chlamydial protease impedes intracellular bacterial growth

Chlamydiae are obligate intracellular bacteria that propagate in a cytosolic vacuole. Recent work has shown that growth of Chlamydia induces the fragmentation of the Golgi apparatus (GA) into ministacks, which facilitates the acquisition of host lipids into the growing inclusion. GA fragmentation results from infection-associated cleavage of the integral GA protein, golgin-84. Golgin-84-cleavage, GA fragmentation and growth of Chlamydia trachomatis can be blocked by the peptide inhibitor WEHD-fmk. Here we identify the bacterial protease chlamydial protease-like activity factor (CPAF) as the factor mediating cleavage of golgin-84 and as the target of WEHD-fmk-inhibition. WEHD-fmk blocked cleavage of golgin-84 as well as cleavage of known CPAF targets during infection with C. trachomatis and C. pneumoniae. The same effect was seen when active CPAF was expressed in non-infected cells and in a cell-free system. Ectopic expression of active CPAF in non-infected cells was sufficient for GA fragmentation. GA fragmentation required the small GTPases Rab6 and Rab11 downstream of CPAF-activity. These results define CPAF as the first protein that is essential for replication of Chlamydia. We suggest that this role makes CPAF a potential anti-infective therapeutic target.

Chlamydiae are bacteria that replicate only inside host (for instance human) cells and that are frequent agents of human disease, in particular sexually transmitted disease. Chlamydia lives in a vacuole inside the cell, surrounded by a lipid membrane, and must acquire nutrients and other factors from the host cell for its replication and for the growth of the vacuole. Recent results show that for this, Chlamydia relies on its ability to induce the loss of an individual protein of the Golgi apparatus (a cellular structure that sorts materials for transport in the cell) called golgin-84. In this work we find that Chlamydia does this using its protein-cleaving enzyme CPAF (which is made by Chlamydia and transported from the vacuole into the cell). CPAF cleaves golgin-84 and thereby induces changes in the Golgi apparatus that are linked to the acquisition of some cellular material by Chlamydia. We further show that a synthetic inhibitor, which was recently found to block chlamydial growth, does that by inhibiting CPAF. CPAF therefore seems necessary for chlamydial growth and blocking CPAF may be a therapeutic strategy against infections with Chlamydia.

A pharmacy-based private chlamydia screening programme: results from the first 2 years of screening and treatment

OBJECTIVE

A major UK Pharmacy chain private Chlamydia screening and treatment service began in October 2006. People pay for a screening kit, send off a urine sample, and are informed of their result directly. Treatment is accessed via the pharmacy chain or the National Health Service. We analysed data from the first 2 years of the service to describe the positivity rate by age and gender, profile of users and to determine if the program succeeded in reaching those who are currently being missed in other clinical settings.

SETTING

Three hundred and thirty-eight community pharmacies from a major pharmacy chain in England and Wales.

METHODS

Cross sectional study of the first 2 years screening and treatment data. Data was collected on number of tests, test results, age and gender. Data was also collected on treatment uptake by age and gender. Further Data regarding the treatment service including the site, was collected on customer record forms. Positivity data was analysed using χ(2).

RESULTS

A total of 14,378 private Chlamydia screening tests were performed in pharmacies during the 2 year period. Overall positivity rates in males (9.8%) were higher than females (6.8%). The positivity rate was significantly higher in the 16-24 age group than in the 25 and over age group. A total of 533 people accessed and paid for treatment from Boots out of a total of 1,131 people who tested positive (47.1%). Hundred and thirty three (25.0%) partners also accessed treatment.

CONCLUSIONS

The data further supports the feasibility and acceptability of pharmacy testing and treatment.

Chlamydia trachomatis secretion of hypothetical protein CT622 into host cell cytoplasm via a secretion pathway that can be inhibited by the type III secretion system inhibitor compound 1

Using antibodies raised with C. trachomatis fusion proteins, we localized a hypothetical protein encoded by the ORF ct622 in the cytoplasm of C. trachomatis-infected mammalian cells. The detection was specific since the antibody labelling of CT622 protein was removed by preabsorption with CT622 but not other fusion proteins. We similarly confirmed that CT621, a known secretion protein encoded by a hypothetical ORF downstream of ct622, was secreted into host cell cytosol. Proteins CT622 and CT621 displayed a similar secretion pattern, with both intra-inclusion and host cell cytosol localization, that was distinct from that of CPAF (chlamydial protease/proteasome-like activity factor). However, the expression and secretion kinetics differed significantly between CT622 and CT621: CT622 mRNA was detected at 2 h, protein at 6 h and secretion of protein into host cell cytoplasm at 36 h post-infection, while CT621 mRNA was detected at 8 h, protein at 16 h and secretion at 24 h. The secretion of both CT622 and CT621 was blocked by N'-(3,5-dibromo-2-hydroxybenzylidene)-4-nitrobenzohydrazide (compound 1), an inhibitor known to target the type III secretion system of bacteria. These results suggest that CT621 and CT622 may fulfil different functions during chlamydial intracellular growth. Further characterization of these proteins may generate important information for understanding chlamydial pathogenesis.

[Improvement of treatment of inflammatory diseases in oral cavity]

In order to determine the anti-pathogenic clinical efficacy of cycloferon liniment in the combined treatment of herpetic stomatitis and periodontitis, medical examination and treatment of these disorders have been carried out in a group of 80 patients. It is established that the use of cycloferon liniment in the combined treatment of herpetic stomatitis and periodontitis decreases the infectious load in parodontal recess, reduces the manifestations of local inflammation, normalizes the immunity indices, and decreases the level of endogenous intoxication, which ensures the acceleration of recuperation processes and lowers the frequency of recurrences.

Synergistic effect of ultrasound and antibiotics against Chlamydia trachomatis-infected human epithelial cells in vitro

To investigate whether or not the combined ultrasound and antibiotic treatment is effective against chlamydial infection, a new ultrasound exposure system was designed to treat chlamydia-infected cells. First, the minimum inhibitory concentrations of antibiotics against Chlamydia trachomatis were determined. Infected cultures were treated with antibiotics then sonicated at intensity of 0.15 or 0.44 W/cm(2) with or without Bubble liposomes. After 48 or 72 h after infection, chlamydial inclusions were stained and examined by fluorescence microscopy. The internalization of dextran-fluorescein conjugates by ultrasound irradiation with Bubble liposomes was observed by fluorescence microscopy. The results showed that application of nanobubble-enhanced ultrasound caused no significant effect on cell viability and chlamydial infectivity. However, Doxycycline (1/2 MIC) or CZX (1.0 μg/ml) in combination with nanobubble-enhanced ultrasound dramatically reduced the number of inclusions compared with that administered with antibiotics only. Bubble dose-dependent synergy was also observed. After ultrasound irradiation at intensity of 0.44 W/cm(2) on the presence of Bubble liposomes, 10% of HeLa cells were observed to have internalized the dextran molecules. This study suggests the possibility of using nanobubble-enhanced ultrasound to deliver antibiotic molecules into cells to eradiate intracellular bacteria, such as chlamydiae, without causing much damage to the cells itself.

In vitro activities of several antimicrobial agents against recently isolated and genotyped Chlamydia trachomatis urogenital serovars D through K

A systematic evaluation of the susceptibility of all Chlamydia trachomatis urogenital serovars (D through K) to levofloxacin, erythromycin, doxycycline, clarithromycin, and azithromycin was performed. All C. trachomatis serovars had comparable susceptibilities with respect to the various antimicrobials tested, thus confirming the homogeneous data so far obtained regarding the susceptibility of C. trachomatis to antimicrobial agents.

Targeting antibiotics to households for trachoma control

Background

Mass drug administration (MDA) is part of the current trachoma control strategy, but it can be costly and results in many uninfected individuals receiving treatment. Here we explore whether alternative, targeted approaches are effective antibiotic-sparing strategies.

Methodology/Principal Findings

We analysed data on the prevalence of ocular infection with Chlamydia trachomatis and of active trachoma disease among 4,436 individuals from two communities in The Gambia (West Africa) and two communities in Tanzania (East Africa). An age- and household-structured mathematical model of transmission was fitted to these data using maximum likelihood. The presence of active inflammatory disease as a marker of infection in a household was, in general, significantly more sensitive (between 79% [95%CI: 60%–92%] and 86% [71%–95%] across the four communities) than as a marker of infection in an individual (24% [16%–33%]–66% [56%–76%]). Model simulations, under the best fit models for each community, showed that targeting treatment to households has the potential to be as effective as and significantly more cost-effective than mass treatment when antibiotics are not donated. The cost (2007US$) per incident infection averted ranged from 1.5 to 3.1 for MDA, from 1.0 to 1.7 for household-targeted treatment assuming equivalent coverage, and from 0.4 to 1.7 if household visits increased treatment coverage to 100% in selected households. Assuming antibiotics were donated, MDA was predicted to be more cost-effective unless opportunity costs incurred by individuals collecting antibiotics were included or household visits improved treatment uptake. Limiting MDA to children was not as effective in reducing infection as the other aforementioned distribution strategies.

Conclusions/Significance

Our model suggests that targeting antibiotics to households with active trachoma has the potential to be a cost-effective trachoma control measure, but further work is required to assess if costs can be reduced and to what extent the approach can increase the treatment coverage of infected individuals compared to MDA in different settings.

Repeated ocular infection with the bacterium Chlamydia trachomatis leads to the development of trachoma, a major cause of infectious blindness worldwide. Mass distribution of antibiotics, a component of the current trachoma control strategy, has had success in reducing infection in some areas, but results in a large number of uninfected people receiving antibiotics. We have previously shown that transmission of the bacteria between people in the same household is very efficient. Here, we investigated the effectiveness and cost-effectiveness of targeting antibiotics to households with active trachoma (inflammatory disease) compared to mass distribution, using data from four trachoma-endemic populations and a mathematical model of transmission. We found a high correspondence between households with active trachoma and infected households. In all populations the household targeted approach was predicted to be as effective as mass distribution, but it reduced the number of uninfected individuals receiving antibiotics, making the targeted strategy more cost-effective when antibiotics are not donated. Assuming antibiotics are donated, we predicted the targeted strategy to be more cost effective if it increases the proportion of infected individuals receiving treatment. Further work to address the feasibility and the cost variability in implementing the targeted approach in different settings is now required.

Candidate vaginal microbicides with activity against Chlamydia trachomatis and Neisseriagonorrhoeae

Vaginal microbicides with activity towards organisms that cause sexually transmitted infections have been proposed as a strategy to reduce transmission. Small-molecule inhibitors of Chlamydia trachomatis serovar D belonging to the class of salicylidene acylhydrazides (INPs) have been shown to work through a mechanism that involves iron restriction. Expanding on this work, ten INPs were tested against a lymphogranuloma venereum strain of C. trachomatis (serovar L2), Neisseria gonorrhoeae, and hydrogen peroxide-producing Lactobacillus crispatus and Lactobacillus jensenii. Seven INPs had minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations of <50 microM towards C. trachomatis L2. Three INPs had a MIC <12.5 microM against N. gonorrhoeae. Inhibition was reversed by iron, holo-transferrin and holo-lactoferrin but not by the iron-poor forms of these compounds. The compounds exhibited no bactericidal activity toward Lactobacillus. The INPs were not cytotoxic to HeLa 229 cells. When INP 0341 was tested in a mouse model of a Chlamydia vaginal infection there was a significant reduction in the number of mice shedding C. trachomatis up to 4 days after infection (P<0.01). In summary, select INPs are promising vaginal microbicide candidates as they inhibit the growth of two common sexually transmitted organisms in vitro, are active in a mouse model against C. trachomatis, are not cytotoxic and do not inhibit organisms that compose the normal vaginal flora.

[Clinical application of azithromycin extended-release (ER) formulation to treat female sexually transmitted infection]

The prevalence of female sexually transmitted infection (STI) in Japan is in the decreasing tendency after 2002, however it still actualizes as a social problem. Azithromycin, which is 15-member macrolide antimicrobial agent, has indication to treat the chlamydia STI in a single dose of 1 g. In April 2009, a single dose of 2 g of azithromycin extended release (ER) formulation, which is improved formulation by the viewpoint of pharmacokinetics-pharmacodynamics, was approved and has indications to treat not only chlamydial STI but also gonococcal STI. We considered the clinical application of azithromycin ER to treat female STI, including our new our own experiences because the clinical studies of azithromycin ER for STI had not been conducted. In conclusion, azithromycin ER was suggested theoretically becoming one of the choices of new treatment STI caused by not only chlamydia but also gonococcus, more clinical consideration to treat STI will be necessary in the future.

[Determining antimicrobial resistance to Chlamydia trachomatis and applying present findings in daily practice]

Chlamydia trachomatis (C. trachomatis) is the most common bacterial causative agent of sexually transmitted diseases today. Treatment outcome will depend on the choice of antimicrobial drug. Therefore, it is very important to know antimicrobial sensitivity of this pathogen. Cultivation in cell culture is a method of choice for diagnosis of C. trachomatis infection, in terms of medico-legal investigations and follow-up after completed therapy, but also serves for determining the antimicrobial sensitivity of C. trachomatis. Tetracyclines, macrolides and kinolones are commonly used in the treatment of the C. trachomatis infection. Resistance to these antibiotics was described for strains isolated from unsuccessfully treated patients. All described resistant clinical strains demonstrated in vitro heterotypic resistance. To date no homotypic resistance was described for human isolates. An evaluation of antimicrobial resistance and treatment outcome in C. trachomatis infection is complicated by the lack of standardized tests, as well as by the fact that in vitro resistance does not correlate with clinical outcome. In case of any suspicion of unsuccessful treatment of genitourinary infection caused by C. trachomatis isolation should be attempted and isolated strains forwarded to a specialized laboratory.

Effects of baicalin on Chlamydia trachomatis infection in vitro

Baicalin has emerged as a promising agent for the therapy of infectious diseases due to the increasing number of pathogenic microbial strains resistant to several antibiotics. In this study, we investigated the inhibitory activity of baicalin on Chlamydia infection in vitro. We found that baicalin blocked the infection of HeLa cells in vitro when added to the infected cells. In order to shed light on the inhibitory effects of baicalin on the Chlamydia-infected cells, the expression of RFX5 and Chlamydia protease-like activity factor (CPAF) mRNAs and proteins in the Chlamydia-infected cells were examined using Western blot and real-time RT-PCR analysis. The results demonstrated that RFX5 and CPAF were upregulated and downregulated, respectively, by baicalin. Because CPAF is responsible for degrading RFX5, it is suggested that CPAF is a primary target of baicalin and plays an important role in downregulating RFX5. In conclusion, our findings demonstrated that baicalin can effectively inhibit Chlamydia Trachomatis in HeLa cells and therefore can be considered a potential agent for the therapy of infectious diseases caused by C. trachomatis.

Penicillin induced persistence in Chlamydia trachomatis: high quality time lapse video analysis of the developmental cycle

BACKGROUND

Chlamydia trachomatis is a major human pathogen with a unique obligate intracellular developmental cycle that takes place inside a modified cytoplasmic structure known as an inclusion. Following entry into a cell, the infectious elementary body (EB) differentiates into a non-infectious replicative form known as a reticulate body (RB). RBs divide by binary fission and at the end of the cycle they redifferentiate into EBs. Treatment of C.trachomatis with penicillin prevents maturation of RBs which survive and enlarge to become aberrant RBs within the inclusion in a non-infective persistent state. Persistently infected individuals may be a reservoir for chlamydial infection. The C.trachomatis genome encodes the enzymes for peptidoglycan (PG) biosynthesis but a PG sacculus has never been detected. This coupled to the action of penicillin is known as the chlamydial anomaly. We have applied video microscopy and quantitative DNA assays to the chlamydial developmental cycle to assess the effects of penicillin treatment and establish a framework for investigating penicillin induced chlamydial persistence.

PRINCIPAL FINDINGS

Addition of penicillin at the time of cell infection does not prevent uptake and the establishment of an inclusion. EB to RB transition occurs but bacterial cytokinesis is arrested by the second binary fission. RBs continue to enlarge but not divide in the presence of penicillin. The normal developmental cycle can be recovered by the removal of penicillin although the large, aberrant RBs do not revert to the normal smaller size but remain present to the completion of the developmental cycle. Chromosomal and plasmid DNA replication is unaffected by the addition of penicillin but the arrest of bacterial cytokinesis under these conditions results in RBs accumulating multiple copies of the genome.

CONCLUSIONS

We have applied video time lapse microscopy to the study of the chlamydial developmental cycle. Linked with accurate measures of genome replication this provides a defined framework to analyse the developmental cycle and to investigate and provide new insights into the effects of antibiotic treatments. Removal of penicillin allows recovery of the normal developmental cycle by 10-20 hrs and the process occurs by budding from aberrant RBs.

Trachoma surveillance annual report, 2008. A report by the National Trachoma Surveillance and Reporting Unit

The National Trachoma Surveillance and Reporting Unit has reported data for trachoma endemic regions and communities in the Northern Territory, South Australia and Western Australia for 2006 to 2008. Aboriginal children aged 1-9 years were examined using the World Health Organization grading criteria. Screening in the Northern Territory was conducted by the primary health care staff from the Healthy School Age Kids program, the Australian Government Emergency Intervention and Aboriginal Community Controlled Health Services. Forty-three of 92 communities in 6 regions were screened and reported data (2,462 children). In South Australia, the Eye Health and Chronic Disease Specialist Support Program and a team of eye specialists visited 11 of 72 communities in regions serviced by 6 Aboriginal Community Controlled Health Services (365 children). In Western Australia, population health unit and primary health care staff screened and reported data for 67 of 123 communities in 4 regions (1,823 children). Prevalence rates of active trachoma varied between the regions with reported prevalence ranging from 4%-67% in the Northern Territory, 0%-13% in South Australia and 8%-25% in Western Australia. Statistical comparisons must be viewed with caution due to the year-to-year variation in the coverage of children examined and the small numbers. Comparisons of 2006, 2007 and 2008 regional prevalence of active trachoma showed that many communities had no change in prevalence, though there were a few statistically significant increases and decreases (P<0.05). The number of communities screened and the number of children examined has improved but still remains low for some regions. The implementation of the World Health Organization Surgery (for trichiasis), Antibiotics (with azithromycin), Facial cleanliness and Environmental improvement (SAFE) strategy has been variable. Few data continue to be reported for the surgery and environmental improvement components. In general, the availability of the community programs for surgery, antibiotic treatment, and facial cleanliness has improved. Reporting of antibiotic treatment has improved from 2006 to 2008. No significant changes were noted in bacterial resistance reported by pathology services from 2007 to 2008; these rates are comparable to national data collected by the Advisory Group on Antibiotic Resistance in 2005.

Chlamydia trachomatisand male fertility

There is increasing evidence that the function of human spermatozoa can be significantly affected by direct exposure to the bacterium Chlamydia trachomatis. This may contribute to sub-fertility in infected individuals by a route that is independent of any damage to the reproductive epithelium. In addition, if a C. trachomatis infection is undiagnosed it could contribute to poor outcomes in assisted conception techniques such as in vitro fertilization. The antibiotics routinely used in IVF culture systems are largely ineffective against chlamydia, emphasizing the importance of screening patients prior to treatment. Moreover, given the many thousands of semen samples provided for analysis by men in primary care (many of which will never undergo assisted conception treatment), it is suggested that this may represent a wasted opportunity to provide screening (and treatment) for the infection using an appropriate test specimen and without the need for additional hospital visits.

When can antibiotic treatments for trachoma be discontinued? Graduating communities in three African countries

BACKGROUND

Repeated mass azithromycin distributions are effective in controlling the ocular strains of chlamydia that cause trachoma. However, it is unclear when treatments can be discontinued. Investigators have proposed graduating communities when the prevalence of infection identified in children decreases below a threshold. While this can be tested empirically, results will not be available for years. Here we use a mathematical model to predict results with different graduation strategies in three African countries.

METHODS

A stochastic model of trachoma transmission was constructed, using the parameters with the maximum likelihood of obtaining results observed from studies in Tanzania (with 16% infection in children pre-treatment), The Gambia (9%), and Ethiopia (64%). The expected prevalence of infection at 3 years was obtained, given different thresholds for graduation and varying the characteristics of the diagnostic test.

RESULTS

The model projects that three annual treatments at 80% coverage would reduce the mean prevalence of infection to 0.03% in Tanzanian, 2.4% in Gambian, and 12.9% in the Ethiopian communities. If communities graduate when the prevalence of infection falls below 5%, then the mean prevalence at 3 years with the new strategy would be 0.3%, 3.9%, and 14.4%, respectively. Graduations reduced antibiotic usage by 63% in Tanzania, 56% in The Gambia, and 11% in Ethiopia.

CONCLUSION

Models suggest that graduating communities from a program when the infection is reduced to 5% is a reasonable strategy and could reduce the amount of antibiotic distributed in some areas by more than 2-fold.

[Diagnosis of urethritis in men. A 3-year review]

OBJECTIVES

The aim of this study is to know the prevalence and tendency of microorganisms producing urethritis, in men, in the City Centre of Madrid.

METHODS

Cross-sectional study. The urethral samples of 1.248 men were analyzed, for 3 years. The samples were studied for: GRAM stain, when secretion exists; culture in habitual plates; detection of C. trachomatis, U. urealyticum and M. hominis, when there was suspicious, study of T. vaginalis and when suspicious injuries exist, study of virus Herpes simplex.

RESULTS

The percentage of positive samples was 22.60%. The isolated microorganisms were: U. urealyticum 7.61%, N. gonorrhoeae 6.33%, C. trachomatis 4.81%, M. hominis 0.24%, H. parainfluenzae 1.76%, H. influenzae 1.12%, Candida spp 0.48%, S. pyogenes 0.16% and Herpes virus simplex (2) 0.08%. Two or more microorganisms were isolated in 1.68%. The percentage of positive samples in 2003 was 17.41% and N. gonorrhoeae the most frequent microorganism (6.22%). In 2004 was 25.57% and the most frequent U. urealyticum (10.18%). In 2005 the 24.50% of the samples were positive and U. urealyticum the most frequent (7.92%). The 79.41% of N. gonorrhoeae were susceptible to all antibiotics tested. It is not found resistance to ceftriaxone, claritromicine and amoxicilline/clavulanic acid. The 11.76% were betalactamase- producing. The 26.47% of Haemophilus spp. were betalactamase- producing and all strains were susceptible to cefotaxime.

CONCLUSIONS

The isolated microorganisms most frequently were: U. urealyticum, N. gonorrhoeae and C. trachomatis. There is an increase of 7% of prevalence between the years 2003 and 2005. Ceftriaxone, claritromicine and amoxicilline/clavulanic acid were susceptible to all the strains studied and cefotaxime to all Haemophilus spp.

[Analysis of the infection status and the drug resistance of mycoplasma and chlamydiae in genitourinary tracts of children with suspected nongonococcal urethritis]

OBJECTIVE

To investigate the infection and the drug resistance status of mycoplasma and chlamydiae in genitourinary tracts of children with suspected nongonococcal urethritis (NGU) and provide information for clinical rational administration of antimicrobial agents.

METHODS

Samples of genitourinary tract secretion from 146 children who were suspected of having nongonococcal urethritis or colpitis were collected and tested for mycoplasma via culture and for chlamydia with antigen detection. Meanwhile, susceptibility test was carried out on the samples which were positive in mycoplasma cultivation. Chlamydia antigen was detected by the polymer conjugate-enhanced (PCE) indirect enzyme immunoassay (EIA) (IDEIA PCE Chlamydia; DAKO). The mycoplasma culture medium was produced by Nanjing Liming Biological Products Co,. Ltd. Antibiotics used for susceptibility test were erythromycin, roxithromycin, josamycin, leucomycin, meleumycin, rovamycin, azithromycin, clarithromycin, cycloate erythromycin, and clindamycin.

RESULTS

Fifteen samples were positive for Chlamydia trachomatis (Ct) by antigen detection (10.3%), 82 samples were positive in mycoplasma cultivation (56.2%), and among the 82 samples, 58 were positive for Ureaplasma urealyticum (Uu, 39.7%), 9 were positive for Mycoplasma hominis (Mh, 6.2%), and 15 were positive for Uu and Mh (10.3%). Of all the samples, 4 were positive for both Uu and Ct (2.7%). The rates of drug resistance of the 10 commonly used antibiotics were as follows: erythromycin 32.9%, roxithromycin 41.5%, josamycin 19.5%, leucomycin 22.0%, meleumycin 28.0%, rovamycin 30.5%, azithromycin 37.8%, clarithromycin 26.8%, davercin 24.4%, and clindamycin 26.8%, respectively. The results indicated that drug resistance rates of josamycin and leucomycin were the lowest, and the rates of roxithromycin and azithromycin were the highest.

CONCLUSIONS

The infection rates of mycoplasma and chlamydia in children suspected NGU were high. Mycoplasma showed drug resistance to a different degree to 10 common antibiotics. The results of chemosensitivity showed that josamycin had the highest susceptibility rate.

The cell-penetrating peptide, Pep-1, has activity against intracellular chlamydial growth but not extracellular forms of Chlamydia trachomatis

OBJECTIVES

In the course of studies to identify novel treatment strategies against the pathogenic bacterium, Chlamydia, we tested the carrier peptide, Pep-1, for activity against an intracellular infection.

METHODS

Using a cell culture model of Chlamydia trachomatis infection, the effect of Pep-1 was measured by incubating the peptide with extracellular chlamydiae prior to infection, or by adding Pep-1 to the medium at varying times after infection, and assaying for inhibition of inclusion formation.

RESULTS

Pep-1 had a concentration-dependent effect on chlamydial growth with 100% inhibition of inclusion formation at 8 mg/L peptide. There was a window of susceptibility during the chlamydial developmental cycle with a maximal effect when treatment was begun within 12 h of infection. Pep-1 treatment caused a severe reduction in the production of infectious progeny even when started later, when the effect on inclusion formation was minimal. Furthermore, electron micrographs showed a paucity of progeny elementary bodies (EBs) in the inclusion. In contrast, pre-incubation of EBs with Pep-1 prior to infection did not affect inclusion formation. Taken together, these findings indicate that the antichlamydial effect was specific for the intracellular stage of chlamydial infection. By comparison, Pep-1 had no antimicrobial activity against Escherichia coli and Staphylococcus aureus or the obligate intracellular parasite, Toxoplasma gondii.

CONCLUSIONS

Pep-1 has antichlamydial activity by preventing intracellular chlamydial growth and replication but has no effect on extracellular chlamydiae.

Sonodynamic therapy

Recently, there have been numerous reports on the application of non-thermal ultrasound energy for treating various diseases in combination with drugs. Furthermore, the introduction of microbubbles and nanobubbles as carriers/enhancers of drugs has added a whole new dimension to therapeutic ultrasound. Non-thermal mechanisms for effects seen include various forms of energy due to cavitation, acoustic streaming, micro jets and radiation force which increases possibilities for targeting tissue with drugs, enhancing drug effectiveness or even chemically activating certain materials. Examples such as enhancement of thrombolytic agents by ultrasound have proven to be beneficial for acute stroke patients and peripheral arterial occlusions. Non-invasive low intensity focused ultrasound in conjunction with anti-cancer drugs may help to reduce tumor size and lessen recurrence while reducing severe drug side effects. Chemical activation of drugs by ultrasound energy for treatment of atherosclerosis and tumors is another new field recently termed as "Sonodynamic therapy". Lastly, advances in molecular imaging have aroused great expectations in applying ultrasound for both diagnosis and therapy simultaneously. Microbubbles or nanobubbles targeted at the molecular level will allow medical doctors to make a final diagnosis of a disease using ultrasound imaging and then immediately proceed to a therapeutic ultrasound treatment.

Effects of levofloxacin and doxycycline on interleukin-6 production of Chlamydia trachomatis-infected human synovial fibroblasts

BACKGROUND

A large amount (80,000-100,000 pg/ml) of interleukin-6 (IL-6) was detected in cultures of human synoviocytes infected with Chlamydia trachomatis. In this study, we investigated the effect of antibiotics on the IL-6 production of C. trachomatis-infected human fibroblast-like synovial cells (HFLS).

METHODS

The minimum inhibitory concentrations of levofloxacin and doxycycline against C. trachomatis were determined in either HFLS or HeLa 229 cells. The number of live Chlamydia was also examined. IL-6 in the supernatants of infected cultures was quantified by capture ELISA.

RESULTS

The production of IL-6 was suppressed to as low as 1,800 pg/ml in the infected HFLS treated with levofloxacin or doxycycline immediately or early after infection. In HFLS treated with levofloxacin and doxycycline, the IL-6 levels decreased to 37,000 and 21,000 pg/ml, respectively, 48 h after infection, and levofloxacin was thus found to be less effective than doxycycline. In addition, the number of viable C. trachomatis in the infected cultures treated with levofloxacin 24 h after infection was higher than when treated with doxycycline.

CONCLUSIONS

The early administration and proper selection of antibiotics is important for the suppression of inflammatory cytokine production. These findings indicate that antibiotic therapy will not only work in treating infections but might also be useful in treating reactive arthritis secondary to the infection.

Can nucleic acid amplification tests be used to test for chlamydia and gonorrhoea in microbicide trials?

Microbicides may interfere with detection of Chlamydia trachomatis (Ct) and Neisseria gonorrhoeae (Ng) in urine samples from women who use microbicides. The inhibitory effects of BufferGel, PRO2000 and PRO2000 placebo, in urine samples, were determined by nucleic acid amplification tests (NAATs). Uninfected urine was inoculated with different concentrations (10(5)-10(1) organisms/mL); microbicides were added to achieve final concentrations from 5% to 0.1%. Specimens were tested using strand displacement amplification (SDA) for Ct and Ng. Samples with BufferGel demonstrated no inhibition. Samples with PRO2000 showed inhibition at the 5% concentration when tested for Ct, whereas for Ng, PRO2000 showed inhibition at 5%, 2% and some 1% concentrations. The placebo showed no inhibition when detecting Ct, and variable inhibition at the 5% and 2% concentrations for Ng. The potential inhibitory effects of microbicides on the NAATs selected for detection of Ct and Ng should be considered in clinical trials involving topical microbicides.

Efficacy of a dish detergent in reducing populations of STI organisms in inoculated female condoms

We assessed the efficacy of dish detergent in removing Neisseria gonorrhoeae, HIV-1, herpes simplex virus type 2 and Chlamydia trachomatis organisms from the surface of inoculated female condoms. The reductions achieved in organism counts with dish detergent were compared with those for household bleach and water. New (out-of-package) and pre-washed/re-lubricated female condoms were used. Dish detergent was as efficacious as bleach in reducing organism counts from the surface of inoculated female condoms. Both bleach and dish detergent performed better than water, although >3 log(10) reductions were achieved with water alone. There was little difference in organism reduction between new and pre-washed condoms. Furthermore, 30 seconds of mechanical agitation (washing) had minimal added impact on organism removal. Reduction in organism counts with water alone suggests that dilution effect may have been as important in organism removal as the microbicidal properties of the detergent.

Characterization of in vitro chlamydial cultures in low-oxygen atmospheres

To mimic in vivo conditions during chlamydial infections, Chlamydia trachomatis serovar D and Chlamydia pneumoniae CWL029 were cultured in low-oxygen atmospheres containing 4% O(2), with parallel controls cultured in atmospheric air. Both were enriched with 5% CO(2). The results showed a dramatic increase in the growth of C. pneumoniae but not of C. trachomatis.