Escherichia coli (E coli) Infections Medication

Updated: May 18, 2017
  • Author: Tarun Madappa, MD, MPH; Chief Editor: Michael Stuart Bronze, MD  more...
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Medication

Medication Summary

E coli meningitis requires antibiotics, such as third-generation cephalosporins (eg, ceftriaxone).

E coli pneumonia requires respiratory support, adequate oxygenation, and antibiotics, such as third-generation cephalosporins or fluoroquinolones.

E coli cholecystitis/cholangitis requires antibiotics such as third-generation cephalosporins that cover E coli and Klebsiella organisms. Empiric coverage should also include anti– E faecalis coverage.

For E coli intra-abdominal abscess, antibiotics also must include anaerobic coverage (eg, ampicillin and sulbactam or cefoxitin). In severe infection, piperacillin and tazobactam, imipenem and cilastatin, or meropenem may be used. Combination therapy with antibiotics that cover E coli plus an antianaerobe can also be used (eg, levofloxacin plus clindamycin or metronidazole).

E coli enteric infections require fluid replacement with solutions containing appropriate electrolytes. Antimicrobials known to be useful in cases of traveler's diarrhea include doxycycline, trimethoprim/sulfamethoxazole (TMP/SMZ), fluoroquinolones, and rifaximin. They shorten the duration of diarrhea by 24-36 h. Antibiotics are not useful in enterohemorrhagic E coli (EHEC) infection and may predispose to development of HUS. Antimotility agents are contraindicated in children and in persons with enteroinvasive E coli (EIEC) infection.

Uncomplicated E coli cystitis can be treated with a single dose of antibiotic or 3-d course of a fluoroquinolone, TMP/SMZ, or nitrofurantoin.

Recurrent E coli cystitis (ie, >2 episodes/y) is treated with continuous or postcoital prophylaxis with a fluoroquinolone, TMP/SMZ, or nitrofurantoin.

Patients with complex cases (eg, those with diabetes, >65 y, or recent history of UTI) are treated with a 7- to 14-d course of antibiotics (eg, levofloxacin, third-generation cephalosporins, or aztreonam).

Acute uncomplicated E coli pyelonephritis in young women is treated with fluoroquinolone or TMP/SMZ for 14 d. Patients with vomiting, nausea, or underlying illness (eg, diabetes) should be admitted to the hospital. If fever and flank pain persist for more than 72 h, ultrasonography or CT scanning may be performed.

Treat E coli perinephric abscess or prostatitis with at least 6 wk of antibiotics.

E coli sepsis requires at least 2 wk of antibiotics and identification of the source of bacteremia based on imaging study results.

McGannon et al found that antibiotics that target DNA synthesis, such as ciprofloxacin (CIP) and TMP/SMZ, showed increased Shiga toxin production, whereas antibiotics that target the cell wall, transcription, or translation did not. [6] Remarkably, high levels of Shiga toxin were detected even when growth of O157:H7 was completely suppressed by CIP. In contrast, azithromycin significantly reduced Shiga toxin levels even when O157:H7 viability remained high.

Since the late 1990s, multidrug-resistant Enterobacteriaceae (mostly E coli) that produce extended-spectrum beta-lactamases (ESBLs), such as the CTX-M enzymes, have emerged within the community setting as an important cause of UTIs. These bacteria are resistant to the groups of antibiotics that are commonly used to treat these types of infections (penicillins, cephalosporins) and to antibiotics normally reserved for more severe infections (eg, fluoroquinolones, gentamicin).

The spread of CTX-M–positive bacteria considerably changes how the treatment of community-acquired infections is approached and limits the oral antibiotics that may be administered. This finding has major implications for treating individuals who do not clinically respond to first-line antibiotics. [7]

In one study, mortality following bacteremic infection caused by ESBL producing E coli was significantly higher than non–ESBL-producing E coli. These findings have serious implications for antibiotic prescription, as cephalosporins are ineffective treatment for many E coli infections. [8]

Infections due to ESBL-producing E coli have largely been regarded as a healthcare-associated phenomenon. However, reports of community-associated infections caused by ESBL-producing E coli have begun to emerge and this occurrence of community-associated infections due to extended-spectrum β-lactamase (ESBL)–producing Escherichia coli has been recognized among patients without discernible healthcare-associated risk factors in the United States. Most (54.2%) ESBL-producing strains that cause community-associated episodes belonged to ST131 or its related sequence types. Among these strains, all except one produced CTX-M–type ESBL, in particular CTX-M-15. [9]

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Antibiotics

Class Summary

Empiric antimicrobial therapy must be comprehensive and cover all likely pathogens in the context of the clinical setting. However, given the broad use of antibiotics in hospitals, a study was performed to determine the relationship between hospital use of 16 classes of antibacterial agents and the incidence of quinolone-resistant E coli isolates. The results revealed that although the level of hospital use of quinolones influenced the incidence of quinolone resistance in E coli hospital isolates, the consumption of 2 other classes of antibiotics, cephalosporins and tetracyclines, is also associated with quinolone resistance. [10]

Recent data from the Canadian national surveillance study, CANWARD, revealed that 868 urine isolates of E coli collected from 2010-2013 were sensitive to fosfomycin using the Clinical and Laboratory Standards Institute (CLSI) agar dilution method, with minimum inhibitory concentrations (MICs) interpreted using CLSI M100-S23 (2013) criteria. The concentrations of fosfomycin inhibiting 50% (MIC 50 ) and 90% (MIC 90 ) of isolates were 1 or less and 4 μg/mL, respectivelyl; 99.4% of isolates were susceptible to fosfomycin. [11]

Doxycycline (Vibramycin, Adoxa, Doryx, Morgidox, Monodox)

Doxycycline inhibits protein synthesis and thus, bacterial growth, by binding to the 30S and possibly 50S ribosomal subunits of susceptible bacteria. It is used to treat traveler's diarrhea.

Trimethoprim/sulfamethoxazole (Bactrim, Bactrim DS, Septra DS, Sulfatrim)

Trimethoprim/sulfamethoxazole inhibits bacterial growth by inhibiting the synthesis of dihydrofolic acid. It is used to treat traveler's diarrhea for 5 days, uncomplicated UTI for 3 days, complicated UTI for 10-14 days, and acute prostatitis for 6-12 weeks.

Ciprofloxacin (Cipro)

Ciprofloxacin is a fluoroquinolone that inhibits bacterial DNA synthesis and, consequently, growth. It is used to treat mild-to-moderate UTI for 7-14 days, acute uncomplicated cystitis for 3 days, severe-to-complicated UTI for 7-14 days, infectious diarrhea for 5-7 days, and chronic bacterial prostatitis for 4-6 weeks.

Levofloxacin (Levaquin)

Levofloxacin is used for infections due to multidrug-resistant gram-negative organisms. It is used to treat community-acquired pneumonia for 7-14 days, acute pyelonephritis and complicated UTI for 10 days, and traveler's diarrhea for 5 days.

Amoxicillin (Moxatag)

Amoxicillin interferes with the synthesis of cell wall mucopeptides during active multiplication, resulting in bactericidal activity against susceptible bacteria. It is used to treat uncomplicated UTI for 7 days and complicated UTI or pyelonephritis for 10-14 days.

Aztreonam (Azactam)

Aztreonam is a monobactam that inhibits cell wall synthesis during bacterial growth. It is active against aerobic gram-negative bacilli. It is used to treat complicated UTIs/pyelonephritis and bacteremia for 7-14 days, intra-abdominal infections for 14-21 days, and pneumonia for 14 days.

Ampicillin and sulbactam (Unasyn)

Ampicillin and sulbactam is a drug combination of a beta-lactamase inhibitor with ampicillin. It is used to treat intra-abdominal infections for 14-21 days.

Nitrofurantoin (Macrodantin, Macrobid, Furadantin)

Nitrofurantoin is synthetic nitrofuran and interferes with bacterial carbohydrate metabolism by inhibiting acetylcoenzyme A. It is used to treat uncomplicated UTIs for 7 days or for 3 days after urine is sterile.

Meropenem (Merrem IV)

Meropenem is a bactericidal broad-spectrum carbapenem antibiotic that inhibits cell wall synthesis. It is effective against most gram-positive and gram-negative bacteria. It is used to treat intra-abdominal infections for 14-21 days.

Ceftriaxone (Rocephin)

Ceftriaxone is a third-generation cephalosporin that arrests bacterial growth by binding to one or more penicillin-binding proteins. It is used to treat meningitis and bacteremia for 14-21 days and pneumonia, complicated UTI, or pyelonephritis for 14 days.

Piperacillin and tazobactam (Zosyn)

Piperacillin and tazobactam is an antipseudomonal penicillin plus beta-lactamase inhibitor. It inhibits biosynthesis of cell wall mucopeptide and is effective during the stage of active multiplication. It is used to treat intra-abdominal infections for 14-21 days.

Imipenem and cilastatin (Primaxin)

The imipenem and cilastatin combination is for treatment of multiple-organism infections in which other agents do not have wide-spectrum coverage or are contraindicated due to potential for toxicity. It is used to treat pneumonia and complicated UTI for 14 days, bacteremia for 7 days, and intra-abdominal abscess for 14-21 days.

Rifaximin (Xifaxan)

Rifaximin is a nonabsorbed (< 0.4%), broad-spectrum antibiotic specific for enteric pathogens of the GI tract (ie, gram-positive, gram-negative, aerobic, anaerobic). It is a rifampin structural analog, and it binds to the beta-subunit of bacterial DNA-dependent RNA polymerase, thereby inhibiting RNA synthesis. It is indicated for E coli (enterotoxigenic and enteroaggregative strains) associated with travelers' diarrhea.

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