Resistance urinary tract infections

Mixtures of sulfas (eg, the tri-sulfapyrimidines) have also been used for this purpose. Resistant organisms frequently result after a urinary tract infection has been treated with sulfonamides, however. 

Cefuroxime (35) is effective against community-acquired pneumonia in which ampicillin-resistant Haemophilus influence is the probable etiologic agent. Cefoxitin (23) is used to treat mixed aerobic—anaerobic infections including pelvic infections, intra-abdorninal infections, and nosocomial aspiration pneumonia. Cefonicid (31), because of its long half-life has been used in a once-a-day regimen to treat a variety of mild to moderate infections including community-acquired pneumonias, urinary tract infections, and infections of the skin and soft tissue (132,215). 

Gupta K, Sahm DF, Mayfield D, et al. Antimicrobial resistance among uropathogens that cause community-acquired urinary tract infections in women a nationwide analysis. Clin Infect Dis 2001 33 89-94. 

Perfetto EM, Gondek EK. Escherichia coli resistance in uncomplicated urinary tract infection a model for determining when to change first-line empirical antibiotic choice. Manag Care Interface 2002 6 35M2. 

MRSA, methicillin-resistant S. aureus PVD, peripheral vascular disease IJTI, urinary tract infection. 

Compound 21a in combination with ceftazidime or cefpirome at a ratio of 1 1 was observed to have efficacy in vivo [96]. It improved the efficacy of both the cephalosporins in both a murine systemic infection model with cephalosporinase-resistant rods and in urinary tract infection models with cephalosporin-resistant P. aeruginosa. Further developments in this class of compounds would be rewarding. 

Resistance to the drugs has developed over time current uses include treatment of gonorrhea, and upper and lower urinary tract infections in both sexes. 

Levofloxacin (1), the levo-isomer or the (5)-enantiomer of ofloxacin, received FDA approval in 1996 (Fish, 2003 Hurst et al., 2002 Mascaretti, 2003 Norrby, 1999 North et al., 1998). The initial approval covered community-acquired pneumonia, acute bacterial exacerbation of chronic bronchitis, acute maxillary sinusitis, uncomplicated skin and skin structure infections, acute pyelonephritis, and complicated urinary tract infections (North et al., 1998). Four years later, the levofloxacin indication list grew to include community-acquired pneumonia caused by penicillin-resistant Streptococcus pneumoniae. In addition, in 2002, nosocomial (hospital-acquired) pneumonia caused by methicillin-susceptible Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcescens, Haemophilus influenzae, Kliebsella pneumoniae, and Escherichia coli was added (Hurst et al., 2002). Finally in 2004, LVX was approved as a post-exposure treatment for individuals exposed to Bacillus anthracis, the microbe that causes anthrax, via inhalation (FDA, 2004). 

For infections frequently encountered outside hospitals, e.g. uncomplicated urinary tract infection in young women, surveillance of resistance data of the most likely pathogens Escherichia coli) allows physicians to prescribe empiric therapy without performing cultures in the individual patient. However, in severely ill hospitalised patients, it is necessary to take samples for culture before starting empiric therapy. Microscopy of the Gram stained smear can help fine-tune empiric therapy at an early stage. Whether the infection is community-acquired or hospital-acquired, and whether the patient has been exposed to previous antimicrobial therapy should also be taken into account when choosing empiric therapy. 

Acute uncomplicated urinary tract infections caused by E. coli and other pathogens generally respond promptly to one of the short-acting sulfonamides. Recurrent urinary tract infections (UTIs), when related to some structural abnormality in the tract, are frequently caused by sulfonamide-resistant bacteria. 

Therapeutic uses of the quinolones include urinary and respiratory tract infections, GI and abdominal infections, STDs, and bone, joint, and soft tissue infections. Nalidixic acid is effective for urinary tract infections however, bacteria can become resistant, particularly if the drug is used for long periods. The second-generation fluoroquinolones are all equally efficacious in UTIs, and their activity is comparable to that of TMP-SMX. These drugs have shown efficacy in treating prostatitis and can serve as an alternative therapy for patients not responding to TMP-SMX. 

Since cephalosporin C is only one-thousandth as active as benzylpenicillin, its use is very limited. However, it is remarkably resistant to enzymatic hydrolysis and becomes highly concentrated in the urine, which makes it useful in urinary tract infections caused by Gram-negative organisms. 

The fluoroquinolones represent an important therapeutic advance and are extremely useful agents. They are important for the treatment of Gram-negative urinary tract infections, especially those from sulfa-resistant strains of E. coli, and for the treatment of serious hacterial infections such as those caused by Pseudomonas aeruginosa. On the basis of microbiological considerations, the fluoroquinolones may be further subdivided into three groups ... 

After oral administration, it is rapidly absorbed and is distributed in various body tissues including CSF. It is excreted largely unchanged in urine by glomerular filtration. It is used for treatment of multidrug resistant tuberculosis with other primary drugs. It is also used in acute urinary tract infections caused by susceptible microorganisms. 

A combination of trimethoprim-sulfamethoxazole is effective treatment for a wide variety of infections including P jiroveci pneumonia, shigellosis, systemic salmonella infections, urinary tract infections, prostatitis, and some nontuberculous mycobacterial infections. It is active against most Staphylococcus aureus strains, both methicillin-susceptible and methicillin-resistant, and against respiratory tract pathogens such as the pneumococcus, Haemophilus sp, Moraxella catarrhalis, and Klebsiella pneumoniae (but not Mycoplasma pneumoniae). However, the increasing prevalence of strains of E coli (up to 30% or more) and pneumococci that are resistant to trimethoprim-sulfamethoxazole must be considered before using this combination for empirical therapy of upper urinary tract infections or pneumonia. 

Nitrofurantoin is bacteriostatic and bactericidal for many gram-positive and gram-negative bacteria but P aeruginosa and many strains of proteus are resistant. There is no cross-resistance between nitrofurantoin and other antimicrobial agents and resistance emerges slowly. As Escherichia coli resistant to trimethoprim-sulfamethoxazole and fluoroquinolones has become more common, nitrofurantoin has become an important alternative oral agent for treatment of uncomplicated urinary tract infection. 

There is no regimen that is reliably bactericidal for vancomycin-resistant enterococcus for which there is extensive clinical experience daptomycin has bactericidal activity in vitro. Regimens that have been reported to be efficacious include nitrofurantoin (for urinary tract infection) potential regimens for bacteremia include daptomycin, linezolid, and dalfopristin/quinupristin. 

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