[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.

Immunization with recombinant actin from Trypanosoma evansi induces protective immunity against T. evansi, T. equiperdum and T. b. brucei infection.

Actin gene of Trypanosoma evansi (STIB 806) was cloned and expressed in Escherichia coli. The predicted amino acid sequence of T. evansi actin shows 100%, 98.7%, and 93.1%, homology with Trypanosoma equiperdum, Trypanosoma brucei brucei, and Trypanosoma cruzi. Recombinant actin was expressed as inclusion bodies in E. coli. It was purified and renatured for immunological studies. Mice immunized with the renatured recombinant actin were protected from lethal challenge with T. evansi STIB 806, T. equiperdum STIB 818, and T. b. brucei STIB 940, showing 63.3%, 56.7%, and 53.3% protection, respectively. Serum collected from the rabbit immunized with recombinant actin inhibited the growth of T. evansi, T. equiperdum, and T. b. brucei in vitro cultivation. Serum from mice and rabbits immunized with recombinant actin only recognized T. evansi actin but not mouse actin. The results of this study suggest that the recombinant T. evansi actin induces protective immunity against T. evansi, T. equiperdum, and T. b. brucei infection and may be useful in the development of a vaccine with other cytoskeletal proteins to prevent animal trypanosomiasis caused by these three trypanosome species.