Posts filed under ‘Infecciones urinarias’

Understanding the Mechanism of Bacterial Biofilms Resistance to Antimicrobial Agents.

Open Microbiol J. 2017 Apr 28;11:53-62.

Singh S1, Singh SK2, Chowdhury I3, Singh R2.

1 Department of Kriya Sharir, Institute of Medical Sciences, Banaras Hindu University, Varanasi- 221 005 UP India.

2 Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, Atlanta, GA, USA.

3 Department of Obstetrics and Gynecology; Morehouse School of Medicine, Atlanta, GA, USA.


A biofilm is a group of microorganisms, that causes health problems for the patients with indwelling medical devices via attachment of cells to the surface matrix. It increases the resistance of a microorganism for antimicrobial agents and developed the human infection. Current strategies are removed or prevent the microbial colonies from the medical devices, which are attached to the surfaces. This will improve the clinical outcomes in favor of the patients suffering from serious infectious diseases. Moreover, the identification and inhibition of genes, which have the major role in biofilm formation, could be the effective approach for health care systems. In a current review article, we are highlighting the biofilm matrix and molecular mechanism of antimicrobial resistance in bacterial biofilms.




October 14, 2018 at 10:44 am

Biofilms: survival mechanisms of clinically relevant microorganisms.

Clinical Microbiology Reviews April 2002 V.15 N.2 P.167-93.

Donlan RM1, Costerton JW.

1 Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.


Though biofilms were first described by Antonie van Leeuwenhoek, the theory describing the biofilm process was not developed until 1978. We now understand that biofilms are universal, occurring in aquatic and industrial water systems as well as a large number of environments and medical devices relevant for public health. Using tools such as the scanning electron microscope and, more recently, the confocal laser scanning microscope, biofilm researchers now understand that biofilms are not unstructured, homogeneous deposits of cells and accumulated slime, but complex communities of surface-associated cells enclosed in a polymer matrix containing open water channels. Further studies have shown that the biofilm phenotype can be described in terms of the genes expressed by biofilm-associated cells. Microorganisms growing in a biofilm are highly resistant to antimicrobial agents by one or more mechanisms. Biofilm-associated microorganisms have been shown to be associated with several human diseases, such as native valve endocarditis and cystic fibrosis, and to colonize a wide variety of medical devices. Though epidemiologic evidence points to biofilms as a source of several infectious diseases, the exact mechanisms by which biofilm-associated microorganisms elicit disease are poorly understood. Detachment of cells or cell aggregates, production of endotoxin, increased resistance to the host immune system, and provision of a niche for the generation of resistant organisms are all biofilm processes which could initiate the disease process. Effective strategies to prevent or control biofilms on medical devices must take into consideration the unique and tenacious nature of biofilms. Current intervention strategies are designed to prevent initial device colonization, minimize microbial cell attachment to the device, penetrate the biofilm matrix and kill the associated cells, or remove the device from the patient. In the future, treatments may be based on inhibition of genes involved in cell attachment and biofilm formation.


October 14, 2018 at 10:41 am

Biofilm formation: a clinically relevant microbiological process.

Clinical Infectious Disseases October 15, 2001 V.33 N.8 P.1387-92.

Donlan RM1.

1 Biofilm Laboratory, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.


Microorganisms universally attach to surfaces and produce extracellular polysaccharides, resulting in the formation of a biofilm. Biofilms pose a serious problem for public health because of the increased resistance of biofilm-associated organisms to antimicrobial agents and the potential for these organisms to cause infections in patients with indwelling medical devices. An appreciation of the role of biofilms in infection should enhance the clinical decision-making process.




October 14, 2018 at 10:39 am

Commentaries – Fluoroquinolones for urinary tract infection and within-household spread of resistant Enterobacteriaceae: the smoking gun

Clinical Microbiology and Infection september 2018 V.24 N.9  P.929–930

Barbara W. Trautner

The ‘smoking gun hypothesis’ refers to scientific evidence that strongly suggests—but falls just short of demonstrating—a causal relationship. The phrase originated in the 1983 Sherlock Holmes story The Adventure of the Gloria Scott in which the narrator rushes into a ship’s cabin to find a man shot on the floor and the chaplain holding a smoking pistol [1]. The paper in this issue of Clinical Microbiology and Infection by Stewardson et al. [2] presents smoking-gun evidence for the emergence of resistant strains of the Enterobacteriaceae after antibiotic treatment of urinary tract infections (UTIs), both in the treated individual and in the patient’s household contacts…




September 29, 2018 at 10:30 am

Preventing urinary tract infections in patients with neurogenic bladder

LANCET INFECTIOUS DISEASES September 2018 V.18 N.9 P.926-927


Florian M E WagenlehnerAdrian Pilatz

Urological complications are very common among patients with spinal cord injury; development of neurogenic bladder leading to recurrent urinary tract infections (UTIs) and “pyelonephritis being the end condition of a paraplegic”, has determined the fate of these patients for centuries.1 Antibiotic treatment and prevention of UTIs in patients who use clean intermittent self-catheterisation (CISC) have substantially improved the clinical outcomes for patients with neurogenic bladder disturbances.1,  2,  3,  4 However, increasing antibiotic resistance during the past decade has called into question whether long-term antibiotic prophylaxis is useful in many types of recurrent UTIs. In recurrent uncomplicated cystitis, guidelines primarily recommend non-antibiotic prophylaxis strategies to reduce the emergence of antibiotic resistance…




LANCET INFECTIOUS DISEASES September 2018 V.18 N.9 P.957-968


Continuous low-dose antibiotic prophylaxis for adults with repeated urinary tract infections (AnTIC): a randomised, open-label trial

Holly Fisher, PhDYemi Oluboyede, PhDThomas Chadwick, PhDMohamed Abdel-Fattah, MBCatherine Brennand, MScProf Mandy Fader, PhDSimon Harrison, MChirPaul Hilton, MDJames Larcombe, PhDP …


Repeated symptomatic urinary tract infections (UTIs) affect 25% of people who use clean intermittent self-catheterisation (CISC) to empty their bladder. We aimed to determine the benefits, harms, and cost-effectiveness of continuous low-dose antibiotic prophylaxis for prevention of recurrent UTIs in adult users of CISC.


In this randomised, open-label, superiority trial, we enrolled participants from 51 UK National Health Service organisations. These participants were community-dwelling (as opposed to hospital inpatient) users of CISC with recurrent UTIs. We randomly allocated participants (1:1) to receive either antibiotic prophylaxis once daily (prophylaxis group) or no prophylaxis (control group) for 12 months by use of an internet-based system with permuted blocks of variable length. Trial and laboratory staff who assessed outcomes were masked to allocation but participants were aware of their treatment group. The primary outcome was the incidence of symptomatic, antibiotic-treated UTIs over 12 months. Participants who completed at least 6 months of follow-up were assumed to provide a reliable estimate of UTI incidence and were included in the analysis of the primary outcome. Change in antimicrobial resistance of urinary and faecal bacteria was monitored as a secondary outcome. The AnTIC trial is registered at ISRCTN, number 67145101; and EudraCT, number 2013-002556-32.


Between Nov 25, 2013, and Jan 29, 2016, we screened 1743 adult users of CISC for eligibility, of whom 404 (23%) participants were enrolled between Nov 26, 2013, and Jan 31, 2016. Of these 404 participants, 203 (50%) were allocated to receive prophylaxis and 201 (50%) to receive no prophylaxis. 1339 participants were excluded before randomisation. The primary analysis included 181 (89%) adults allocated to the prophylaxis group and 180 (90%) adults in the no prophylaxis (control) group. 22 participants in the prophylaxis group and 21 participants in the control group were not included in the primary analysis because they were missing follow-up data before 6 months. The incidence of symptomatic antibiotic-treated UTIs over 12 months was 1·3 cases per person-year (95% CI 1·1–1·6) in the prophylaxis group and 2·6 (2·3–2·9) in the control group, giving an incidence rate ratio of 0·52 (0·44–0·61; p<0·0001), indicating a 48% reduction in UTI frequency after treatment with prophylaxis. Use of prophylaxis was well tolerated: we recorded 22 minor adverse events in the prophylaxis group related to antibiotic prophylaxis during the study, predominantly gastrointestinal disturbance (six participants), skin rash (six participants), and candidal infection (four participants). However, resistance against the antibiotics used for UTI treatment was more frequent in urinary isolates from the prophylaxis group than in those from the control group at 9–12 months of trial participation (nitrofurantoin 12 [24%] of 51 participants from the prophylaxis group vs six [9%] of 64 participants from the control group with at least one isolate; p=0·038), trimethoprim (34 [67%] of 51 vs 21 [33%] of 64; p=0·0003), and co-trimoxazole (26 [53%] of 49 vs 15 [24%] of 62; p=0·002).


Continuous antibiotic prophylaxis is effective in reducing UTI frequency in CISC users with recurrent UTIs, and it is well tolerated in these individuals. However, increased resistance of urinary bacteria is a concern that requires surveillance if prophylaxis is started.


UK National Institute for Health Research.



August 25, 2018 at 11:09 am

Actinotignum schaalii Infection: A Clandestine Cause of Sterile Pyuria?

Open Forum Infectious Diseases, February 2018 V.5 N.2

Lucy E Horton; Sanjay R Mehta; Lejla Aganovic; Joshua Fierer

Actinotignum schaalii is an underappreciated cause of urinary tract infections (UTIs) in older adults. The diagnosis may be missed due to difficulty isolating and identifying the organism. Complications can result because the organism is intrinsically resistant to 2 commonly used drugs to treat UTI, as illustrated by this case.



July 30, 2018 at 9:21 am

Biomarker guided triage can reduce hospitalization rate in community acquired febrile urinary tract infection

Journal of Infection July 2018 V.76 N.7 P.18–24

Janneke Evelyne Stalenhoef, Cees van Nieuwkoop, Darius Cameron Wilson, Willize Elizabeth van der Starre, Nathalie Manon Delfos, Eliane Madeleine Sophie Leyten, Ted Koster, Hans Christiaan Ablij, Johannes(Jan) Willem van’t Wout, Jaap Tamino van Dissel


  • Biomarkers are assessed to predict disease severity in febrile urinary tract infection.
  • MRproADM has a higher predictive value for a complicated course than PCT or CRP.
  • MRproADM and PCT were significantly higher in patients directly hospitalized.
  • Outpatients requiring subsequent hospitalization had higher MRproADM concentrations.
  • MRproADM guided triage may decrease hospitalization rate without compromising safety.


Febrile urinary tract infections (fUTI) can often be treated safely with oral antimicrobials in an outpatient setting. However, a minority of patients develop complications that may progress into septic shock. An accurate assessment of disease severity upon emergency department (ED) presentation is therefore crucial in order to guide the most appropriate triage and treatment decisions.


Consecutive patients were enrolled with presumptive fUTI across 7 EDs in the Netherlands. The biomarkers mid-regional proadrenomedullin (MR-proADM), procalcitonin (PCT), C-reactive protein (CRP), and a clinical score (PRACTICE), were compared in their ability to predict a clinically severe course of fUTI, initial hospital admission and subsequent readmission using area under the receiver operating characteristic (AUROC) curves.


Biomarker concentrations were measured in 313 patients, with 259 (83%) hospitalized upon ED presentation, and 54 (17%) treated as outpatients. Of these outpatients, 12 (22%) were later hospitalized. MR-proADM had the highest diagnostic accuracy for predicting a complicated fUTI (AUROC [95% CI]: 0.86 [0.79–0.92]), followed by PCT (AUROC [95% CI]: 0.69 [0.58–0.80]). MR-proADM concentrations were unique in being significantly elevated in patients directly admitted and in outpatients requiring subsequent hospitalization, compared to those completing treatment at home. A virtual triage algorithm with an MR-proADM cut-off of 0.80  nmol/L resulted in a hospitalization rate of 66%, with only 2% secondary admissions.


MR-proADM could accurately predict a severe course in patients with fUTI, and identify greater patient numbers who could be safely managed as outpatients. An initial assessment on ED presentation may focus resources to patients with highest disease severities.



July 28, 2018 at 7:31 pm

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