Resistance to fluoroquinolone

Fluoroquinolones arenot recommended for treating infections in MSM or infections acquired in Hawaii, California, or other parts of the world where high-level resistance to fluoroquinolones is reported, or in heterosexuals with a history of recent foreign travel (including exposure froma partner with a history of recent foreign travel). 

Alteration in the target enzyme, DNA gyrase, has resulted In resistance to fluoroquinolones. ... 

Everett MJ, Piddock LJV. Mechanisms of resistance to fluoroquinolones. In Quinolone Antibacterials. Kuhlmann J, DalhoffA, Zeiler H-J (Eds.) Springer Berlin, Heidelberg, New York, Barcelona, Budapest, Hong Kong, London, Milan, Paris, Santa Clara, Singapore, Tokyo, 1998, pp. 259-296. 

Mathon L, Decaillot F, Allaouchiche B. Impact de I anti-biotherapie initiale sur 1 evolution des resistances aux fluoroquinolones et aux aminosides des bacilles a gram negatif isoles chez des patients de reanimation. [Impact of initial antibiotic therapy on the course of resistance to fluoroquinolones and aminoglycosides in Gram-negative bacilli isolated from intensive care patients.] Ann Fr Anesth Reanim 1999 18(10) 1054-60. 

From 8419 worldwide clinical isolates of Streptococcus pneumoniae associated with lower respiratory tract or blood infections obtained from 519 geographically distinct hospital laboratories during 1997-98,69 had reduced susceptibility or resistance to fluoroquinolones. Only mutations in parC and gyrA (especially in combination), but not in gyrB or parE, contributed significantly to... 

Goettsch W, van Pelt W, Nagelkerke N, Hendrix MG, Buiting AG, Petit PL, Sabbe LJ, van Griethuysen AJ, de Neehng AJ. Increasing resistance to fluoroquinolones in Escherichia coli from urinary tract infections in the nether-lands. J Antimicrob Chemother 2000 46(2) 223-8. 

Concern has been raised about staphylococci resistance to fluoroquinolones. Methicillin-resistant S. aureus infections do not respond... 

One of the worrisome issues in the treatment of typhoid fever is the emergence of Salmonella typhi strain resistant to ampicillin, amoxicillin and chloramphinicol. There are also reports of resistance to fluoroquinolones and multidrug resistance. This threat places a high priority for prevention and control of typhoid fever by sanitary measures, especially safe water and sewage disposal, as well as the development of new drugs. 

Answer A- Microbial resistance to fluoroquinolones is increasing, and some strains of Streptococcus pneumoniae are now resistant to ciprofloxacin. The mechanism can involve changes in the structure of topoisomerase IV, one of the targets of fluoroquinolones, which inhibit nucleic acid synthesis. Pneumococcal resistance to penicillins is also increasing via changes in penicillin-binding proteins (PBPs). The other mechanisms listed underlie microbial resistance to other antibiotics as follows sulfonamides (choice B), macrolides (choice C), extended-spectrum penicillins (choice D), and beta-lactams (choice E). 

A single oral dose of a fluoroquinolone such as ofloxacin or ciprofloxacin is effective treatment for sensitive strains of N. gonorrhoeae, but increasing resistance to fluoroquinolones has made... 

Pneumococcal resistance to fluoroquinolones may involve changes in topoisomerase IV Modification of fluoroquinolone dosage is required in patients if creatinine clearance is less than 50 mL/min... 

Both linezolid and co-trimoxazole are antibiotics that are well suited for oral therapy of bone and joint infections caused by otherwise resistant Gram-positive cocci (resistant to fluoroquinolones, macrolides, beta-lactams). 

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