My elderly patient has a WBC count of 60,000 without obvious hematologic malignancy.  How likely is it that his leukocytosis is related to an infection?

Although extremely high WBC count in the absence of myeloproliferative disease may be associated with solid tumors and other causes, infections are often the most common cause of leukemoid reaction (LR), including tuberculosis, Clostridiodes difficile colitis, shigellosis, salmonellosis, pneumonia, abscesses, as well as  parasitic infections (eg, malaria), fungal infections (mucormycosis), and viral diseases (eg, HIV, EBV, Chickungunya fever).1-4   

In a study of 173 hospitalized patients (mean age 69 y) with leukemoid reaction (defined in this study as WBC ≥30,000/µl), infection was the most common cause of LR (48%), followed by tissue ischemia/stress (28%), inflammation (eg, pancreatitis, diverticulitis without perforation) and obstetric diagnoses (7% each) and malignant tumor (5%).1 

In the same study, the most common infections were “sepsis”, pneumonia and urinary tract infections.  Bacteremia was documented in 13%, while Clostridiodes difficile toxin assay was positive in 7% of patients.  The highest WBC counts were observed in patients with either a positive blood culture or positive C. difficile toxin.  In-hospital mortality rate was very high at 62%.

Similarly, in a study involving 105 hospitalized patients, the most common cause was infection, followed by malignancy and other causes. 2 In a smaller study of 25 patients with “extreme” leukocytosis (defined as WBC ≥50,000/µl) infection was considered the cause in 52% and malignancy in 44% of patients; about one-third were bacteremic (eg, Pseudomonas sp, Streptococcus pneumoniae, E. coli).3

Bonus Pearl: Did you know that besides infections and malignancy, drugs (eg, corticosteroids, epinephrine) and ingestion of ethylene glycol have also been associated with LR? 1,3,4

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References

  1. Potasman I, Grupper M. Leukemoid reaction:Spectrum and prognosis of 173 adult patients. Clin Infect Dis 2013;57:e177-81. https://pubmed.ncbi.nlm.nih.gov/23994818/
  2. Portich JP, Faulhaber GAM. Leudemoid reaction: A 21st-century study. https://pubmed.ncbi.nlm.nih.gov/31765058/
  3. Halkes CJM, Dijstelbloem HM, Eelman Rooda SJ, et al. Extreme leucocytosis: not always leukaemia. The Netherlands J Med 2007;65:248-51. https://pubmed.ncbi.nlm.nih.gov/17656811/
  4. Kumar P, Charaniya R, Sahoo R, et al. Leukemoid reaction in Chickungunya fever. J Clin Diagn Res 2016;10:OD05-OD06. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948452/

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

My elderly patient has a WBC count of 60,000 without obvious hematologic malignancy.  How likely is it that his leukocytosis is related to an infection?

“I go after Streptococcus pneumoniae and many other bacteria causing community-acquired pneumonia with vengeance but lately I have had a hard time keeping up with many gram-negatives, including some E. coli. Who am I?”

Additional hint: “The latest FDA warning against the use of my class of drugs has to do with increased risk of ruptures or tears in the aorta in certain patients, including the elderly and those with hypertension, aortic aneurysm or peripheral vascular disease.” 

Editor’s note: This post is part of the P4P “Talking Therapeutics” series designed to make learning about antibiotics fun. Individual antibiotics give a short description of themselves and you are asked to guess their names. Antimicrobial spectrum, common uses and potential adverse effects follow. Enjoy!

And the answer is…… HERE

Selected antimicrobial spectrum

                Gram-positives: Streptococcus pneumoniae, Staphylococcus aureus                         (some resistance even in MSSA), Enterococcus spp (urine;some resistance)

                Gram-negatives: Enterics (eg, E. coli, Klebsiella spp), Pseudomonas spp,                                 Stenotrophomonas maltophilia, H. influenzae, some ESBLs.

                 AVOID: MRSA, anaerobes

Common clinical uses: community-acquired pneumonia (CAP), healthcare-associated pneumonia (HAP), urinary tract infections (UTIs), legionnaire’s disease, abdominal infection (plus anaerobic coverage)

WATCH OUT! QT prolongation, C. difficile, central nervous system toxicity, seizures, myasthenia gravis, peripheral neuropathy, tendinopathy, drug interactions (eg. warfarin), and most recently aortic aneurysm diagnosis/dissection!

Remember the key features of levofloxacin before you prescribe it!

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Selected references

  1. FDA. FDA warns about increased risk of ruptures or tears in the aorta blood vessel with fluoroquinolone antibiotics in certain patients.  https://www.fda.gov/drugs/drug-safety-and-availability/fda-warns-about-increased-risk-ruptures-or-tears-aorta-blood-vessel-fluoroquinolone-antibiotics. Accessed Nov 26, 2020,.
  2. Marangon FB, Miller D, Muallem MS, et al. Ciprofloxacin and levofloxacin resistance among methicillin-sensitive Staphylococcus aureus isolates from keratitis and conjunctivitis. Am J Ophthal 2004;137:453-58. https://www.ajo.com/article/S0002-9394(03)01287-X/pdf
  3. Yasufuku T, Shigemura K, Shirakawa T, et al. Mechanisms of and risk factors for fluoroquinolone resistance in clinical Enterococcus faecalis from patients with urinary tract infections. J Clin Microbiol 2011;49:3912-16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3209098/
  4.  Rawla P, Helou MLE, Vellipuram AR. Fluoroquinolones and the risk of aortic aneurysm or aortic dissection: A systematic review and meta-analysis. Cardiovasc Hematol Agents Med Chem 2019;17:3-10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6865049/

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

“I go after Streptococcus pneumoniae and many other bacteria causing community-acquired pneumonia with vengeance but lately I have had a hard time keeping up with many gram-negatives, including some E. coli. Who am I?”

Is cefepime an acceptable alternative to carbapenems in the treatment of cefepime susceptible extended spectrum beta-lactamase (ESBL) Gram-negatives?

Irrespective of in-vitro susceptibility results, cefepime should be avoided in the treatment of serious ESBL infections associated with bacteremia, pneumonia, intraabdominal infection, endocarditis, bone/joint infection or whenever a high bacterial inoculum is suspected. Cefepime should be considered only in non-severe infections (eg, uncomplicated urinary tract infection) when the minimum inhibitory concentration (MIC) is 2 mg/L or less (1).

 

To date, clinical studies comparing cefepime vs carbapenem have been small and/or retrospective, often with conflicting results (1). A 2016 propensity score-matched study of patients with ESBL bacteremia receiving cefepime therapy followed by carbapenem therapy vs carbapenem for the entire treatment duration found higher 14 day mortality in the cefepime group (41% vs 20% in the carbapenem group) (2).  Of note, 2 of the patients receiving cefepime who died were infected with an ESBL organism with MIC of 1 mcg/mL. 

 

Another study found cefepime to be inferior to carbapenem therapy in ESBL bacteremic patients with better outcome when cefepime MIC was 1 ug/m or less (3).

 

Two studies involving patients with ESBL UTIs found no significant difference between cefepime and carbapenem in clinical and microbiological response or in-hospital mortality, while another UTI study with a high rate of septic shock (33%) found that cefepime was inferior to carbapenem in clinical and microbiological response (2).

 

The diminished efficacy of cefepime for the treatment of ESBL infections may be related to its “inoculum effect” ie, marked increase in MIC with increased inoculum size compared to that used in standard laboratory susceptibility testing (1,4).   

 

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References

  1. Karaiskos I, Giamarellou H. Carbapenem-sparing strategies for ESBL producers: when and how. Antibiotics 2020;9,61. https://pubmed.ncbi.nlm.nih.gov/32033322/
  2. Wang R, Cosgrove S, Tschudin-Sutter S, et al. Cefepime therapy for cefepime-susceptible extended-spectrum beta-lactamase-producing Enerobacteriaceae bacteremia. Open Forum Infect Dis 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4942761/
  3. Lee NY, Lee CC, Huang WH, et al. Cefepime therapy for monomicrobial bacteremia caused by cefepime-susceptible extended-spectrum beta-lactamase-producing Enterobacteriaceae: MIC matters. Clin Infect Dis 203;56:488-95. https://academic.oup.com/cid/article/56/4/488/351224
  4. Smith KP, Kirby JE. The inoculum effect in the era of multidrug resistance:minor differences in inoculum have dramatic effect on MIC determination. Antimicrob Agents Chemother 2018;62:e00433-18. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6105823/

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Is cefepime an acceptable alternative to carbapenems in the treatment of cefepime susceptible extended spectrum beta-lactamase (ESBL) Gram-negatives?

Could my patient with acute dysuria and less than 10,000 E. coli/ml on urine culture still have a urinary tract infection (UTI)?

Absolutely! Although historically ≥100,000 bacteria/ml has been used as a criterion for UTI based on studies of women with pyelonephritis in the 1950s,1 several studies have since found that this criterion may not be met in up to 50% of symptomatic patients with UTI. 2-6 A lower criterion of 100-1,000 bacteria/ml of urine increases the sensitivity of urine culture to ~90% or more for diagnosis of UTI (albeit with lower specificity). 2-5

A 1982 NEJM study involving UTIs due to coliforms in acutely dysuric women found that the traditional count of ≥100,000 bacteria/ml in midstream urine missed ~50% of cases based on positive bladder cultures. 2 Similarly a 2013 NEJM study reported that 40% of women with symptomatic UTI would be missed if the ≥100,000 bacteria/ml criterion for midstream urine is used. 3

Among symptomatic men, 32% have been found to have <100,000 bacteria/ml in their midstream urine 4 and a single urine specimen by urethral catheterization growing ≥ 100 bacteria/ml is consistent with bacteriuria for both men and women. 5

Since most of these studies have involved UTI caused by E. coli or other coliforms, more data are needed to find out if the same findings apply to non-coliform urinary pathogens.

Bonus Pearl: Did you know that because quantitative urine culture results are concentration dependent (ie, “per ml”), a dilute urine—as may be found in patients experiencing diuresis—will result in lower numbers of bacteria/ ml. 5

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 References

  1. Kass EH. Asymptomatic infections of the urinary tract. Trans Assoc Am Physicians 1958;69:56-74. https://pubmed.ncbi.nlm.nih.gov/13380946/
  2. Stamm WE, Counts GW, Running KR, et al. Diagnosis of coliform infection in acutely dysuric women. N Engl J Med 1982;307:463-8. https://pubmed.ncbi.nlm.nih.gov/7099208/
  3. Hooten TM, Roberts PL, Cox ME, et al. Voided midstream urine culture and acute cystitis in premenopausal women. N Engl J Med 2013;369:1883-91. https://www.nejm.org/doi/full/10.1056/NEJMoa1302186
  4. Lipsky BA, Ireton RC, Fihn SD, et al. Diagnosis of bacteriuria in men: specimen collection and culture interpretation. J Infect Dis 1987;155:847-54. https://pubmed.ncbi.nlm.nih.gov/3559288/
  5. Nicolle LE, Bradley S, Colgan R, et al. Infectious Diseases Society of America Guidelines for the diagnosis and treatment of asymptomatic bacteriuria in adults. Clin Infect Dis 2005;40:643-54. https://pubmed.ncbi.nlm.nih.gov/15714408/
  6. Roberts KB, Wald ER. The diagnosis of UTI: colony count criteria revisited. Pediatrics 2018;141:e20173239. https://doi.org/10.1542/peds.2017-3239

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Could my patient with acute dysuria and less than 10,000 E. coli/ml on urine culture still have a urinary tract infection (UTI)?

How long should I treat my patient with urinary tract infection and E. Coli bacteremia?

Although traditionally 7 to 14 days of antibiotic therapy has been recommended for Gram-negative bacteremia, more recent studies suggest that shorter antibiotic treatment courses are as effective as longer treatments for a variety of infections, particuarly those due to Enterobacteriaceae (eg, E. Coli, Klebsiella sp) in patients with low severity illness (1). 

Keep in mind that short course therapy may not apply to all patients with UTI and bacteremia, such as those with prostatitis (not included in the most recent study [1,2]), which requires longer course of antibiotics (3)

 
A 2019 randomized-controlled study involving primarily patients with bacteremia caused by E. Coli or Klebsiella sp. (~75%) with most cases associated with UTI (~70%) found that 7 days was as effective as 14 days of treatment in hemodynamically stable patients who are afebrile for at least 48 hours without an ongoing focus of infection (1). More specifically, there was no significant difference between the 2 groups in the rates of relapse of bacteremia or mortality at 14 or 28 days.

 
An accompanying editorial concluded that “7 days of treatment may be sufficient for hospitalized, non-critically ill patients with Gram-negative bacteremia and with signs of early response to treatment” (4)  Again, the accent should be on hemodynamically stable patients who respond rapidly to treatment. 

 
Bonus Pearl: While on the subject of shorter course antibiotic therapy, a 2016 “mantra” article nicely summarizes more recent suggestions for common infectious disease conditions (5). Obviously, clinical judgment should be exercised in all cases.
• Community-acquired pneumonia                               3-5 days (vs 7-10 days)
• Nosocomial pneumonia                                                 8 days or less (vs 10-15 days)
• Pyelonephritis                                                                  5-7 days (vs 10-14 days)
• Intraabdominal infection                                             4 days (vs 10 days)
• COPD acute exacerbation                                             5 days or less (vs >6 days)
• Acute bacterial sinusitis                                               5 days (vs 10 days)
• Cellulitis                                                                            5-6 days (vs 10 days)

 

 

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References
1. Yahav D, Franceschini E, Koppel F, et al. Seven versus 14 days of antibiotic therapy for uncomplicated Gram-negative bacteremia: A noninferiority randomized controlled trial. Clin Infect Dis 2019; 69:1091-8. https://academic.oup.com/cid/article/69/7/1091/5237874       2. Yahav D, Mussini C, Leibovici L, et al. Reply to “Should we treat bacteremic prostatitis for 7 days”.  Clin Infect Dis 2010;70:751-3. DOI:10:1093/cid/ciz393.

3.  De Greef J, Doyen L, Hnrard S, et al. Should we treat bacteremic prostatitis for 7 days? Clin Infect Dis 2020;70:351https://academic.oup.com/cid/article-abstract/70/2/351/5488067?redirectedFrom=fulltext
4. Daneman D, Fowler RA. Shortening antibiotic treatment durations for bacteremia. Clin Infect Dis 2019;69:1099-1100. https://academic.oup.com/cid/article-abstract/69/7/1099/5237877?redirectedFrom=fulltext
5. Spellberg B. The new antibiotic mantra: “ Shorter is better”. JAMA Intern Med 2016;176:1254-55. https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2536180

How long should I treat my patient with urinary tract infection and E. Coli bacteremia?

My 70 year old male patient is admitted with 1 day of fever, dysuria, and urinary frequency and urgency, but has a negative urine dipstick test for nitrites and leukocyte esterase. Could he still have acute bacterial prostatitis?

Short answer: Yes! In fact, no routine clinical imaging test can adequately rule out prostatic involvement in men with urinary tract infection (UTI) symptoms (1)! 

Although the presence of nitrites and leukocyte esterase (LE) may have a high positive predictive value for acute bacterial prostatitis (ABP) (~95%), their combined absence has a negative predictive value of only ~70%; ie, we may miss about one-third of patients with UTI symptoms if we relied solely on the results of nitrite and LE urine dipstick (2,3). Negative nitrites alone has a negative predictive value of only ~ 45%, while a negative LE has a negative predictive value of ~60% (3).

To evaluate for ABP, our patient should undergo rectal exam for prostatic tenderness, as should all men with UTI symptoms. The finding of a tender prostate in this setting is supportive of ABP, although its absence will still not rule out this diagnosis because the reported sensitivity of rectal exam may vary from 9% to 100% in ABP (1).

 
Although there may not be a general agreement on the definition of ABP, 2 studies utilizing indium-labeled leukocyte scintigraphy or a combination of PSA levels and transrectal ultrasound have provided evidence for frequent prostatic involvement in men with UTI symptoms (4,5).  In these studies, an inflammatory reaction within the prostate was seen in the majority of cases, even when the digital rectal examination was not painful or when clinicians diagnosed pyelonephritis without prostatitis.

Bonus pearl: Did you know that the lifetime probability of a man receiving a diagnosis of prostatitis is >25% (1)? 

Also see a related P4P pearl: Acute prostatitis and u/a

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References
1. Etienne M, Chavanet P, Sibert L, et al. Acute bacterial prostatitis: heterogeneity in diagnostic criteria and management. Retrospective multicentric analysis of 371 patients diagnosed with acute prostatitis. BMC Infect Dis 2008, 8:12 doi:10.1186/1471-2334-8-12. https://bmcinfectdis.biomedcentral.com/articles/10.1186/1471-2334-8-12
2. Lipsky BA, Byren I, Hoey CT. Treatment of bacterial prostatitis. Clin Infect Dis 2010;50:1641-1652. https://academic.oup.com/cid/article/50/12/1641/305217
3. Etienne M, Pestel-Caron M, Chavanet P, et al. Performance of the urine leukocyte esterase and nitrite dipstick test for the diagnosis of acute prostatitis. Clin Infect Dis 2008; 46:951-53. https://academic.oup.com/cid/article/46/6/951/351423
4. Velasco M, Mateos JJ, Martinez JA, et al. Accurate topographical diagnosis of urinary tract infection in male patients with (111)indium-labelled leukocyte scintigraphy. Eur J Intern Med 2004;15:157-61. https://www.ncbi.nlm.nih.gov/pubmed/15245717
5. Ulleryd P, Zackrisson B, Aus G, et al. Prostatic involvement in men with febrie urinary tract infection as measured by serum prostate-specific antigen and transrectal ultrasonography. BJU Int 1999;84:470-74. https://onlinelibrary.wiley.com/doi/full/10.1046/j.1464-410x.1999.00164.x

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

My 70 year old male patient is admitted with 1 day of fever, dysuria, and urinary frequency and urgency, but has a negative urine dipstick test for nitrites and leukocyte esterase. Could he still have acute bacterial prostatitis?

My hospitalized patient with pneumonia has now suffered an acute myocardial infarction (MI). Can acute infection and MI be related?

Yes! Ample epidemiological studies implicate infection as an important risk factor for MI.1 The increased risk of MI has been observed during the days, weeks, months or even years following an infection.

A 2018 paper reported a several-fold risk of MI during the week after laboratory-confirmed infection caused by a variety of respiratory pathogens such as influenza virus (6-fold), respiratory syncytial virus (4-fold), and other respiratory viruses (3-fold). 2 Among patients hospitalized for pneumococcal pneumonia, 7-8% may suffer an MI.3,4 One study found a 48-fold increase in the risk of MI during the first 15 days after hospitalization for acute bacterial pneumonia.5 Similarly, an increase in the short-term risk of MI has been observed in patients with urinary tract infection and bacteremia.6

The risk of MI appears to be the highest at the onset of infection and correlates with the severity of illness, with the risk being the highest in patients with pneumonia complicated by sepsis, followed by pneumonia and upper respiratory tract infection. Among patients with pneumonia, the risk exceeds the baseline risk for up to 10 years after the event, particularly with more severe infections.1

Potential mechanisms of MI following infections include release of inflammatory cytokines (eg, interleukins 1, 6, tumor necrosis factor alpha) causing activation of inflammatory cells in atherosclerotic plaques, in turn resulting in destabilization of the plaques. In addition, the thrombogenic state of acute infections, platelet and endothelial dysfunction may increase the risk of coronary thrombosis at sites of plaque disruption beyond clinical resolution of the acute infection. 1

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References

  1. Musher DM, Abers MS, Corrales-Medina VF. Acute infection and myocardial infarction. N Engl J Med 2019;380:171-6. https://www.ncbi.nlm.nih.gov/pubmed/30625066
  2. Kwong JC, Schwartz KL, Campitelli MA, et al. Acute myocardial infarction after laboratory-confirmed influenza infection. N Engl J Med 2018;378:345-53. https://www.nejm.org/doi/full/10.1056/NEJMoa1702090
  3. Musher DM, Alexandraki I, Graviss EA, et al. Bacteremic and nonbacteremic pneumococcal pneumonia: a prospective study. Medicine (Baltimore) 2000;79:210-21. https://www.ncbi.nlm.nih.gov/pubmed/10941350
  4. Musher DM, Rueda Am, Kaka As, Mapara SM. The association between pneumococcal pneumonia and acute cardiac events. Clin Infect Dis 2007;45:158-65. https://www.ncbi.nlm.nih.gov/pubmed/17578773
  5. Corrales-Medina VF, Serpa J, Rueda AM, et al. Acute bacterial pneumonia is associated with the occurrence of acute coronary syndromes. Medicine (Baltimore) 2009;88:154-9. https://www.ncbi.nlm.nih.gov/pubmed/19440118
  6. Dalager-Pedersen M, Sogaard M, Schonheyder HC, et al. Risk for myocardial infarction and stroke after community-acquired bacteremia: a 20-year population-based cohort study. Circulation 2014;129:1387-96. https://www.ncbi.nlm.nih.gov/pubmed/24523433

 

My hospitalized patient with pneumonia has now suffered an acute myocardial infarction (MI). Can acute infection and MI be related?

My previously healthy patient is admitted with a multi-drug resistant E. coli urinary tract infection. Could her urinary tract infection (UTI) be foodborne?

Yes! Although foodborne infections are often thought to cause infections limited to the GI tract, an increasing number of studies have linked foodborne E.coli to extraintestinal infections in humans, including UTIs.1

Supportive data include frequent genetic similarly between antimicrobial-resistant E. coli from humans and poultry-associated E. coli. 2 In fact, antimicrobial-resistant E. coli isolates from humans may be  genetically more similar to poultry isolates than susceptible commensal E. coli strains in the human GI tract.3

A U.S. study found that 14% of chicken meat products were contaminated with E. coli strains capable of causing extraintestinal disease, 1/3 of which were mutli-drug resistant.4  Another study found that 94% of retail chicken meat samples contained E. coli with ESBL-genes,  of which nearly 40% contained isolates present in humans.5

Among women, UTI caused by antimicrobial-resistant extraintestinal pathogenic E. coli has been linked to high levels of self-reported chicken consumption.6

The plausibility of foodborne transmission of antimicrobial-resistant E. coli to humans is further supported by the finding that drug resistant E coli from chicken carcasses widely contaminate the kitchen during meal preparation and can appear in the intestinal tract of those who prepare such food.2

Bonus Pearl: Did you know that women with multi-drug resistant E. coli UTI are 3.7 times more likely to report frequent consumption of chicken? 6

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References

  1. Manges AR. Escherichia coli and urinary tract infections: the role of poultry-meat. Clin Microbiol Infect 2016;22:122-29. https://www.ncbi.nlm.nih.gov/pubmed/26679924
  2. Manges AR, Johnson JR. Reservoirs of extraintestinal pathogenic Escherichia coli. Microbiol Spectrum 2012;3(5):UTI-0006-2012. https://www.ncbi.nlm.nih.gov/pubmed/26542041
  3. Johnson JR, Menard M, Johsnton B, et al. Epidemic clonal groups of Escherichia coli as a cause of antimicrobial-resistant urinary tract infections in Canada, 2002 to 2004. Antimicrob Agents Chemother 53;2733-2739. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2704706/
  4. Johnson JR, Porter SB, Johnston B, et al. Extraintestinal pathogenic and antimicrobial-resistant Escherichia coli, including sequence type 131 (ST131) from retail chicken breasts in the United States in 2013. Apppl Environ Microbiol 83:e02956-16. https://www.ncbi.nlm.nih.gov/pubmed/28062464
  5. Leverstein-van Hall MA, Dierikx CM, Stuart JC, et al. Dutch patients, retail chicken meat and poultry share the same ESBL genes, plasmids and strains. Clin Microbiol Infect 2011;17:873-880. https://www.ncbi.nlm.nih.gov/pubmed/21463397
  6. Manges AR, Smith SP, Lau BJ, et al. Retail meat consumption and the acquisition of antimicrobial resistant Escherichia coli causing urinary tract infections: a case-control study. Foodborne Path Dis 4:419-431. https://www.ncbi.nlm.nih.gov/pubmed/18041952

 

My previously healthy patient is admitted with a multi-drug resistant E. coli urinary tract infection. Could her urinary tract infection (UTI) be foodborne?

Should I consider fosfomycin in the treatment of urinary tract infection in my male patient with suspected prostatitis?

Although fosfomycin (FM) has been approved by the FDA only for the treatment of uncomplicated urinary tract infection (UTI) in women, it may also have a role in the treatment of acute and chronic prostatitis among males given its favorable levels in the prostate tissue. 1-5

Despite lack of studies comparing the efficacy of FM with that of commonly used antibiotics for treatment of prostatitis, the potential utility of FM is supported by several reports of its efficacy in the treatment of prostatitis, including those caused by extended-spectrum beta-lactamase (ESBL)-producing gram-negative rods. 1,4-5

When considering FM for treatment of prostatitis, a higher dose than customary may be needed (3 g once daily, not every 48-72 h) . 4 Although the optimal duration of therapy with FM is unclear in this setting, 12-16 weeks of therapy was used in 2 patients with recurrent UTIs and prostatitis due to multi-drug resistant ESBL-positive E. coli. 4

Given its pharmacokinetics and lack of proven efficacy, avoid FM in pyelonephritis, perinephric abscess or UTI with bacteremia. 2

References

  1. Falagas ME, Vouloumanou EK, Samonis G, et al. Fosfomycin. Clin Microbiol Rev 2016;29:321-347. https://www.ncbi.nlm.nih.gov/pubmed/26960938
  2. Wankum M, Koutsari C, Gens K. Fosfomycin use. Pharmacy Times. November 30, 2017. https://www.pharmacytimes.com/publications/health-system-edition/2017/november2017/fosfomycin-use
  3. Cunha BA, Gran A, Raza M. Persistent extended-spectrum β-lactamase-positive Escherechia coli chronic prostatitis successfully treated with a combination of fosfomycin and doxycycline. International J Antimicrob Agents 2015;45:427-29. https://www.ncbi.nlm.nih.gov/pubmed/25662814
  4. Grayson ML, Macesic N, Trevillyan J, et al. Fosfomycin for treatment of prostatitis: new tricks for old dogs. Clin Infect Dis 2015;61:1141-3. https://www.ncbi.nlm.nih.gov/pubmed/26063723
  5. Falagas ME, Rafailidis PI. Fosfomycin: the current status of the drug. Clin Infect Dis 2015;61:1144-6. https://www.ncbi.nlm.nih.gov/pubmed/26063717
Should I consider fosfomycin in the treatment of urinary tract infection in my male patient with suspected prostatitis?

Should Aerococcus urinae growth from the urine of my elderly patient be considered a pathogen?

Although for many years Aerococcus urinae was considered a urinary contaminant, increasingly it is recognized as an emerging pathogen capable of causing not only urinary tract infection (UTI) but also secondary bacteremia and endocarditis, among others.1   

The proportion of patients with aerococcal bacteriuria with symptoms suggestive of UTI ranges from 55-98%.1 So A. urinae can no longer be assumed to be a contaminant, particularly in the presence of symptoms suggestive of UTI.

A. urinae UTI often affects the elderly (median age 79 y) and those with pre-existing urinary tract pathologies, such as prostatic hyperplasia, urethral stricture, renal calculi, and prior urinary tract surgery.2,3 Many patients also have underlying comorbidities such as diabetes, heart disease, dementia, and chronic renal failure.3

One clue to the presence of A. urinae in the urine is its particularly pungent odor reminiscent of that of patients with trimethylaminuria (fish odor syndrome).4

Once you decide you should treat A. urinae, keep in mind that it is NOT predictably susceptible to trimethoprim-sulfamethoxazole, fluoroquinolones, or fosfomycin!  Instead, consider penicillin, ampicillin, cephalosporin, or nitrofurantoin to which most strains are susceptible.5,6.

 

References

  1. Rasmussen M. Aerococcus: an increasingly acknowledged human pathogen. Clin Microbiol Infect 2016;22:22-27. https://www.ncbi.nlm.nih.gov/pubmed/26454061
  2. Tathireddy H, Settypalli S, Farrell JJ. A rare case of aerococcus urinae infective endocarditis. J Community Hosp Intern Med Perspectives 2017; 7:126-129. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5473194/
  3. Higgins A, Garg T. Aerococcus urinae: An emerging cause of urinary tract infection in older adults with multimordidity and urologic cancer. Urology Case Reports 2017;24-25. https://www.ncbi.nlm.nih.gov/pubmed/28435789
  4. Lenherr N, Berndt A, Ritz N, et al. Aerococcus urinae: a possible reason for malodorus urine in otherwise healthy children. Eur J Pediatr. 2014;173:1115-7 https://www.ncbi.nlm.nih.gov/pubmed/24913181
  5. Christensen JJ, Nielsen XC. Aerococcus urinae. Antimicrobe @ http://www.antimicrobe.orgb75.asp , accessed June 14, 2018.
  6. Dimitriadi D, Charitidou C, Pittaras T, et al. A case of urinary tract infection caused by Aerococcus urinae. J Bacteriol Mycol 2016; 2: 00041. https://pdfs.semanticscholar.org/a1cf/048d8444ce054ca9a332f7c2b4a218325ff6.pdf

 

Should Aerococcus urinae growth from the urine of my elderly patient be considered a pathogen?