Clinically Relevant Antibiotic Resistance Mechanisms Can Enhance the In Vivo Fitness of Neisseria gonorrhoeae

In 2007 the Centers for Disease Control and Prevention placed Neisseria gonorrhoeae on the infamous “Super Bugs” list to highlight the high prevalence of strains resistant to relatively inexpensive antibiotics, such as penicillin, tetracycline and fluoroquinolones, previously used in therapy to treat gonorrhea (Shafer et al., 2010). This event was significant because the gonococcus, a strict human pathogen, causes > 95 million infections worldwide each year and since the mid-1940s mankind has relied on effective antibiotic therapy to treat infections and stop local spread of disease. Today, such therapy is threatened by antibiotic resistance. Specifically, the third generation cephalosporins, especially ceftriaxone, may be losing their effectiveness since some (albeit still rare) isolates in the Far East, most recently Japan, and Europe have displayed clinical resistance to currently used levels of ceftriaxone, and treatment failures have been reported (Ohnishi et al., 2011; Unemo et al., 2010). Concern has been raised that the spectrum of resistance expressed by some gonococcal strains may make standard antibiotic treatment for gonorrhea ineffective in the not too distant future (Dionne-Odom et al., 2011). Without new, effective antibiotics or novel combination therapies of existing antibiotics, the reproductive health of the world’s sexually active population may be placed at risk due to such antibiotic resistant gonococci.