Beata Mlynarczyk-Bonikowska

Plasmid-mediated resistance to tetracyclines among Neisseria gonorrhoeae strains isolated in Poland between 2012 and 2013

Introduction One of two main mechanisms of resistance in tetracycline-resistant Neisseria gonorrhoeae (TRNG) is associated with the presence of TetM protein responsible for actively blocking of the tetracycline target site in the 30S ribosomal subunit. This mechanism is encoded by conjugative plasmids. The second mechanism is chromosomal in nature and due to mutations in specific genes. Aim To determine the incidence and type of tetM determinants in TRNG strains isolated from patients presenting with gonorrhea infection to the Dermatology and Venereology Clinic in Warsaw in 2012–2013. Material and methods Tetracycline and doxycycline susceptibility was determined by E-Tests. The presence and type of the tetM gene were determined by polymerase chain reaction. Results Tetracycline resistance was detected in 50.8% of the evaluated strains. The TRNG strains containing the tetM plasmid constituted 13.8% of all the evaluated strains. Dutch type tetM constituted 12.3% and American type tetM 1.5% of all the evaluated strains. In the remaining TRNG strains, resistance to tetracyclines was presumably chromosome-encoded. The minimal inhibitory concentration (MIC) of tetracycline ranged from 0.25 to 32.0 mg/l, MIC50 = 2.0 mg/l, MIC90 = 32.0 mg/l. The MIC of doxycycline ranged from 0.25 to 32.0 mg/l, MIC50 = 4.0 mg/l, MIC90 = 16.0 mg/l. Conclusions Unlike most of European countries, in 2012–2013 in Poland, the Dutch type tetM was found to be much more common than the American type. Minimal inhibitory concentration values of tetracycline and doxycycline were similar, with doxycycline exhibiting a somewhat lower effectiveness in vitro than tetracycline towards chromosome-mediated tetracycline resistant strains of N. gonorrhoeae.

Antiviral Medication in Sexually Transmitted Diseases. Part II: HIV

This is a second part of a review under a main title Antiviral medication in sexually transmitted diseases. In the part we published in Mini Rev Med Chem. 2013,13(13):1837-45, we have described mechanisms of action and mechanism of resistance to antiviral agents used in genital herpes and genital HPV infection. The Part II review focuses on therapeutic options in HIV infection. In 1987, 6 years after the recognition of AIDS, the FDA approved the first drug against HIV--zidovudine. Since then a lot of antiretroviral drugs are available. The most effective treatment for HIV is highly active antiretroviral therapy--a combination of several antiretroviral medicines that cause a reduction of HIV blood concentration and often results in substantial recovery of impaired immunologic function. At present, there are over 20 drugs licensed and used for the treatment of HIV/AIDS, and these drugs are divided into one of six classes. Investigational agents include GS-7340, the prodrug of tenofovir and BMS-663068--the first in a novel class of drugs that blocks the binding of the HIV gp120 to the CD4 receptor.

Antiviral medication in sexually transmitted diseases. Part III: hepatitis B, hepatitis C.

In the previous parts of the series the antiviral agents used in genital herpes, genital HPV infection and therapeutic options in HIV infections were presented. The sexual contact is one of the major routes in the transmission of HBV and also possible modes of transmission of HCV. In this review we present the clinical indications, mechanisms of action, and side effects of presently available medication for the management of HBV and HCV infections. Currently a revolution is happening in the therapy of chronic hepatitis, especially caused by HCV. Direct-acting antivirals promise to open a new era in treating of chronic HCV infection. Efficacious, simplified and well tolerated interferon-free, and in some cases ribavirin-free regiments are available already and several other inhibitors currently are in the clinical trials.