Decreased Susceptibility to Azithromycin and Doxycycline in Clinical Isolates of<i> Chlamydia trachomatis</i> Obtained from Recurrently Infected Female Patients in India

Abstract

Background: Recurrent genital Chlamydia trachomatis infection often results in serious sequelae and has a major impact on reproductive health. Materials and Methods: Recurrent infections were determined in symptomatic female patients. In vitro susceptibility assay was performed for azithromycin and doxycycline using the cell culture technique against 21 clinical isolates obtained from C. trachomatis-positive patients including those who were recurrently infected. Results: Thirteen isolates (61.9%) were found to be susceptible to azithromycin and doxycycline with minimum inhibitory concentration (MIC) values ≤0.125 and ≤0.25 µg/ml, respectively. Eight isolates (38%) were found to be less susceptible to the drugs. Two of them had MICs of 8 µg/ml for both the drugs and could not be completely eradicated as observed by minimum bactericidal concentration assay. Conclusions: Decreased antibiotic susceptibility to the current first-line drugs (azithromycin and doxycycline) for chlamydial infection treatment was observed in isolates obtained from recurrently infected patients.

Inhibition of Indoleamine 2,3-Dioxygenase Activity by Levo-1-Methyl Tryptophan Blocks Gamma Interferon-Induced Chlamydia trachomatis Persistence in Human Epithelial Cells

“…Problems associated with persistent chlamydial growth include the possibilities that it (i) permits immune evasion (6), (ii) provides a reservoir of bacteria that can be reactivated when conditions in the infected microenvironment are permissive (9,10), and (iii) may underlie the recalcitrance of chlamydiae to some commonly used antibiotics (11,12,39,60). In this study, we explored the effects of the specific IDO1 inhib- We hypothesize that the mechanism underlying the ability of L-1MT to rescue C. trachomatis from IFN-␥-mediated persistence, while limiting the productive multiplication of the bacterium, involves the temporal depletion of tryptophan (Table 4).…”

Human and Pathogen Factors Associated with Chlamydia trachomatis-Related Infertility in Women

“…Batteiger et al (79) showed that repeat infections in 13.7% of their patients were due to possible or probable treatment failures. Additionally, in vitro studies have shown that azithromycin induces chlamydial persistence or heterotrophic resistance (84)(85)(86)(87). Therefore, treatment failure or perhaps indirect failure via persistence could be a contributing factor in the development of infertility in some women via all of the proposed mechanisms.…”

Chlamydia trachomatis Infection and Reproductive Health Outcomes in Women

“…A recent European study that included C. trachomatis isolates from all the urogenital serovars (D through K, n=45) found that all the isolates were susceptible to the antimicrobials tested: levofloxacin, erythromycin, doxycycline, clarithromycin, and azithromycin (33). Nevertheless, in India, decreased antibiotic susceptibility to azithromycin and doxycycline has been reported in 38% -a significant proportion -of the strains isolated in patients with recurrent infections (10). The advisability of monitoring the development of C. trachomatis resistance is hampered by the lack of standardized antimicrobial susceptibility tests, which currently require cell cultures.…”