Infection and Drug Resistance (Jun 2023)
The Effect of Amoxicillin Pre-Exposure on Treatment Outcomes and Antimicrobial Susceptibility in Patients with Urogenital Chlamydia trachomatis Infection
Abstract
Cong You,1 Mingyi Liao,1 Mei Wang,2 Leran Zhao,3 Longnian Li,1 Xiaoying Ye,1 Tao Yang1 1Department of Dermatology and Venereology; Candidate Branch of National Clinical Research Centre for Skin and Immune Diseases, the First Affiliated Hospital of Gannan Medical University, Ganzhou, People’s Republic of China; 2Department of Dermatology, Tianjin First Central Hospital, School of Medicine, Nankai University, Tianjin, People’s Republic of China; 3Department of Dermatology and Venereology, the General Hospital of Tianjin Medical University, Tianjin, People’s Republic of ChinaCorrespondence: Tao Yang, Department of Dermatology and Venereology, Candidate Branch of National Clinical Research Centre for Skin and Immune Diseases, the First Affiliated Hospital of Gannan Medical University, Ganzhou, People’s Republic of China, Tel +8618720732351, Email [email protected]: We investigated the influence of amoxicillin pre-exposure on treatment outcomes, Chlamydia trachomatis (CT) culture, the presence of drug-resistant genes, minimum inhibitory concentrations (MICs), and fractional inhibitory concentrations (FICs) in CT clinical strains. Additionally, we explored the effect of different antimicrobial combinations on CT.Patients and Methods: Clinical data of 62 patients with CT infection were recorded. Of these, 33 had pre-exposure to amoxicillin and 29 did not. Among patients with pre-exposure, 17 received azithromycin and 16 received minocycline. Among the patients without pre-exposure, 15 received azithromycin and 14 received minocycline. All patients underwent microbiological cure follow-ups one month after completing the treatment. 23S rRNA gene mutations, acquisition of tet(M) and tet(C) were detected using reverse transcription PCR (RT-PCR) and PCR, respectively. The MICs and FICs of azithromycin, minocycline, and moxifloxacin, alone or in combination, were determined using the microdilution and checkerboard methods, respectively.Results: More cases of treatment failure occurred in pre-exposed patients, in both treatment groups (P 0.05).Conclusion: Pre-exposure to amoxicillin in CT patients may inhibit CT growth and decrease sensitivity of CT strains to antibiotics. Azithromycin plus moxifloxacin may be a promising treatment regimen for genital CT infections with treatment failure.Keywords: Chlamydia trachomatis, amoxicillin, minimal inhibitory concentrations, fractional inhibitory concentrations, persistent infection
