Posts filed under ‘Resistencia bacteriana’

“Urinary Tract Infection”—Requiem for a Heavyweight

The Journal of the American Geriatrics Society  May 19, 2017

Thomas E. Finucane MD

Johns Hopkins Bayview Medical Center, Baltimore, Maryland

Abstract

“Urinary tract infection” (“UTI”) is an ambiguous, expansive, overused diagnosis that can lead to marked, harmful antibiotic overtreatment. “Significant bacteriuria,” central to most definitions of “UTI,” has little significance in identifying individuals who will benefit from treatment. “Urinary symptoms” are similarly uninformative. Neither criterion is well defined. Bacteriuria and symptoms remit and recur spontaneously. Treatment is standard for acute uncomplicated cystitis and common for asymptomatic bacteriuria, but definite benefits are few. Treatment for “UTI” in older adults with delirium and bacteriuria is widespread but no evidence supports the practice, and expert opinion opposes it.

Sensitive diagnostic tests now demonstrate that healthy urinary tracts host a ubiquitous, complex microbial community. Recognition of this microbiome, largely undetectable using standard agar-based cultures, offers a new perspective on “UTI.” Everyone is bacteriuric. From this perspective, most people who are treated for a “UTI” would probably be better off without treatment. Elderly adults, little studied in this regard, face particular risk. Invasive bacterial diseases such as pyelonephritis and bacteremic bacteriuria are also “UTIs.”

Mindful decisions about antibiotic use will require a far better understanding of how pathogenicity arises within microbial communities. It is likely that public education and meaningful informed-consent discussions about antibiotic treatment of bacteriuria, emphasizing potential harms and uncertain benefits, would reduce overtreatment. Emphasizing the microbiome’s significance and using the term “urinary tract dysbiosis” instead of “UTI” might also help and might encourage mindful study of the relationships among host, aging, microbiome, disease, and antibiotic treatment…..

FULL TEXT

http://onlinelibrary.wiley.com/doi/10.1111/jgs.14907/full

PDF

http://onlinelibrary.wiley.com/doi/10.1111/jgs.14907/epdf

July 20, 2017 at 8:24 am

The Active Component of Aspirin, Salicylic Acid, Promotes Staphylococcus aureus Biofilm Formation in a PIA-dependent Manner

Front. Microbiol. 23 January 2017   

Cristian Dotto1, Andrea Lombarte Serrat1, Natalia Cattelan2, María S. Barbagelata1†, Osvaldo M. Yantorno2, Daniel O. Sordelli1, Monika Ehling-Schulz3, Tom Grunert3 and Fernanda R. Buzzola1*

1 Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Instituto de Investigaciones en Microbiología y Parasitología Médica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina

2 Facultad de Ciencias Exactas, Centro de Investigación y Desarrollo de Fermentaciones Industriales (CINDEFI), Centro Científico Technológico Consejo Nacional de Investigaciones Científicas y Tócnicas (CTT CONICET La Plata), Universidad Nacional de La Plata, La Plata, Argentina

3 Functional Microbiology, Institute for Microbiology, University of Veterinary Medicine, Vienna, Austria

Aspirin has provided clear benefits to human health. But salicylic acid (SAL) -the main aspirin biometabolite- exerts several effects on eukaryote and prokaryote cells. SAL can affect, for instance, the expression of Staphylococcus aureus virulence factors.

SAL can also form complexes with iron cations and it has been shown that different iron chelating molecules diminished the formation of S. aureus biofilm. The aim of this study was to elucidate whether the iron content limitation caused by SAL can modify the S. aureus metabolism and/or metabolic regulators thus changing the expression of the main polysaccharides involved in biofilm formation.

The exposure of biofilm to 2 mM SAL induced a 27% reduction in the intracellular free Fe2+ concentration compared with the controls. In addition, SAL depleted 23% of the available free Fe2+ cation in culture media. These moderate iron-limited conditions promoted …

FULL TEXT

https://doi.org/10.3389/fmicb.2017.00004

 

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July 19, 2017 at 6:53 pm

Increasing Macrolide and Fluoroquinolone Resistance in Mycoplasma genitalium.

Emerg Infect Dis. May, 2017 V.23 N.5 P.809-812.

Murray GL, Bradshaw CS, Bissessor M, Danielewski J, Garland SM, Jensen JS, Fairley CK, Tabrizi SN.

Abstract

Escalating resistance to azithromycin and moxifloxacin is being reported for Mycoplasma genitalium in the Asia-Pacific region.

Analyzing 140 infections, we found pretreatment fluoroquinolone-resistance mutations in parC (13.6%) and gyrA (5%). ParC S83 changes were associated with moxifloxacin failure.

Combined macrolide/fluoroquinolone-resistance mutations were in 8.6% of specimens, for which recommended therapies would be ineffective.

PDF

https://wwwnc.cdc.gov/eid/article/23/5/pdfs/16-1745.pdf

July 19, 2017 at 3:56 pm

Preventing Methicillin-Resistant Staphylococcus aureus (MRSA) Disease in Urban US Hospitals—Now for the Hard Part: More Evidence Pointing to the Community as the Source of MRSA Acquisition

Journal of Infectious Diseases June 1, 2017 V.215 N.11 P.1631-1633

EDITOR’S CHOICE

Susan M. Ray

Methicillin-resistant Staphylococcus aureus (MRSA) first emerged in the 1960s, shortly after the introduction of methicillin for therapeutic use [1].

Over the next 4 decades, MRSA spread worldwide and became endemic in hospitals in many countries [2].

In the 1990s, community- associated MRSA emerged as an epidemic of skin and soft-tissue infections in patients without any prior healthcare contact and was associated with serious morbidity and mortality [3, 4].

Although the earliest reports of community-associated MRSA disease in the United States were due to both USA400 and USA300, it was soon clear that USA300 was the epidemic community-associated MRSA clone of greatest importance in the United States, and it has persisted for well over a decade [5, 6].

By the mid-2000s, USA300 was noted to cause healthcare-associated disease [7], and in some urban centers it now accounts for up to 50% of nosocomial MRSA bacteremias [8] and a high proportion of cases of MRSA disease and colonization in long-term-care facilities [9, 10]….

PDF

https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/jid/215/11/10.1093_infdis_jix109/5/jix109.pdf?Expires=1500037938&Signature=M0o6aaG1nA-QKa5cEmLj56MsouSnLNTmXn-rFt5eerqIhGRsOgr7M9TVLV3yPaZdHI9nXHLygHt02IoXRNC52maaY~kOam~1c1TuDdfcfJ4RwkUOAUOBkKsyEGuzyllVW6j-okbFuBgALwX4MnyilQz~XvqeWt0e7z3JKg4bmLgEj2a5swrFQJHO8t37Jz70wwFyXG4G4mbsUFUuvvRe6UYs6m2MFutBvChhUUPfYlqzW7Y6BL-FZ~F7xLX2PeulV4xZ4ag7AYF8iwDGTLykI~hEkiIgXy7lLZqUsctiu~38reEjq-9Y2GmDmw8GtJeU~lWzyPorY2qcwEY9UhjKqg__&Key-Pair-Id=APKAIUCZBIA4LVPAVW3Q

 

July 13, 2017 at 4:07 pm

Preventing Methicillin-Resistant Staphylococcus aureus (MRSA) Disease in Urban US Hospitals—Now for the Hard Part: More Evidence Pointing to the Community as the Source of MRSA Acquisition

Journal of Infectious Diseases June 1, 2017 V.215 N.11 P.1631-1633

EDITOR’S CHOICE

Susan M. Ray

Methicillin-resistant Staphylococcus aureus (MRSA) first emerged in the 1960s, shortly after the introduction of methicillin for therapeutic use [1].

Over the next 4 decades, MRSA spread worldwide and became endemic in hospitals in many countries [2]. In the 1990s, community- associated MRSA emerged as an epidemic of skin and soft-tissue infections in patients without any prior healthcare contact and was associated with serious morbidity and mortality [3, 4].

Although the earliest reports of community-associated MRSA disease in the United States were due to both USA400 and USA300, it was soon clear that USA300 was the epidemic community-associated MRSA clone of greatest importance in the United States, and it has persisted for well over a decade [5, 6].

By the mid-2000s, USA300 was noted to cause healthcare-associated disease [7], and in some urban centers it now accounts for up to 50% of nosocomial MRSA bacteremias [8] and a high proportion of cases of MRSA disease and colonization in long-term-care facilities [9, 10]….

PDF

https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/jid/215/11/10.1093_infdis_jix109/5/jix109.pdf?Expires=1500037938&Signature=M0o6aaG1nA-QKa5cEmLj56MsouSnLNTmXn-rFt5eerqIhGRsOgr7M9TVLV3yPaZdHI9nXHLygHt02IoXRNC52maaY~kOam~1c1TuDdfcfJ4RwkUOAUOBkKsyEGuzyllVW6j-okbFuBgALwX4MnyilQz~XvqeWt0e7z3JKg4bmLgEj2a5swrFQJHO8t37Jz70wwFyXG4G4mbsUFUuvvRe6UYs6m2MFutBvChhUUPfYlqzW7Y6BL-FZ~F7xLX2PeulV4xZ4ag7AYF8iwDGTLykI~hEkiIgXy7lLZqUsctiu~38reEjq-9Y2GmDmw8GtJeU~lWzyPorY2qcwEY9UhjKqg__&Key-Pair-Id=APKAIUCZBIA4LVPAVW3Q

July 13, 2017 at 8:20 am

Clinical Risk Factors for Infective Endocarditis in Staphylococcus aureus Bacteremia.

Tex Heart Inst J. Feb 1, 2017 V.44 N.1 P.10-15.

Salvador VB, Chapagain B, Joshi A, Brennessel DJ.

Abstract

Crucial to the management of staphylococcal bacteremia is an accurate evaluation of associated endocarditis, which has both therapeutic and prognostic implications. Because the clinical presentation of endocarditis can be nonspecific, the judicious use of echocardiography is important in distinguishing patients at high risk of developing endocarditis.

In the presence of high-risk clinical features, an early transesophageal echocardiogram is warranted without prior transthoracic echocardiography.

The purpose of this study was to investigate the clinical risk factors for staphylococcal infective endocarditis that might warrant earlier transesophageal echocardiography and to describe the incidence of endocarditis in cases of methicillin-resistant and methicillin-sensitive Staphylococcus aureus bacteremia.

A retrospective case-control study was conducted by means of chart review of 91 patients consecutively admitted to a community hospital from January 2009 through January 2013. Clinical risk factors of patients with staphylococcal bacteremia were compared with risk factors of patients who had definite diagnoses of infective endocarditis.

There were 69 patients with bacteremia alone (76%) and 22 patients with endocarditis (24%), as verified by echocardiography. Univariate analysis showed that diabetes mellitus (P=0.024), the presence of an automatic implantable cardioverter-defibrillator/pacemaker (P=0.006) or a prosthetic heart valve (P=0.003), and recent hospitalization (P=0.048) were significantly associated with developing infective endocarditis in patients with S. aureus bacteremia.

The incidence of methicillin-resistant and methicillin-sensitive S. aureus bacteremia was similar in the bacteremia and infective-endocarditis groups (P=0.437).

In conclusion, identified high-risk clinical factors in the presence of bacteremia can suggest infective endocarditis.

Early evaluation with transesophageal echocardiography might well be warranted.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5317353/pdf/i1526-6702-44-1-10.pdf

July 11, 2017 at 4:06 pm

Telavancin: a novel semisynthetic lipoglycopeptide agent to counter the challenge of resistant Gram-positive pathogens.

Ther Adv Infect Dis. March 2017 V.4 N.2 P.49-73.    

Das B1, Sarkar C2, Das D3, Gupta A4, Kalra A1, Sahni S1.

Author information

1 Department of Pharmacology, All India Institute of Medical Sciences (AIIMS) Rishikesh, Rishikesh, India.

2 Department of Pharmacology & Clinical Pharmacology, North Eastern Indira Gandhi Regional Institute of Health & Medical Sciences (NEIGRIHMS) Shillong, Shillong, India.

3 Department of Computer Science & Engineering, Faculty of Engineering, Manipal University Jaipur, Dehmi Kalan, Jaipur Ajmer Expressway, Rajasthan, India.

4 Department of Surgery, All India Institute of Medical Sciences (AIIMS) Rishikesh, Rishikesh, India.

Abstract

Telavancin (TD-6424), a semisynthetic lipoglycopeptide vancomycin-derivative, is a novel antimicrobial agent developed by Theravance for overcoming resistant Gram-positive bacterial infections, specifically methicillin-resistant Staphylococcus aureus (MRSA).

The US Food and Drug Administration (USFDA) had approved telavancin in 2009 for the treatment of complicated skin and skin structure infections (cSSSIs) caused by Gram-positive bacteria, including MRSA (S. aureus, Streptococcus agalactiae, Streptococcus pyogenes, Streptococcus anginosus group, or Enterococcus faecalis).

Telavancin has two proposed mechanisms of action. In vitro, telavancin has a rapid, concentration-dependent bactericidal effect, due to disruption of cell membrane integrity. Telavancin has demonstrable in vitro activity against aerobic and anaerobic Gram-positive bacteria. Telavancin and vancomycin have similar spectra of activity. Gram-negative bacteria are usually non-susceptible to telavancin.

Telavancin has been successfully tested in various animal models of bacteremia, endocarditis, meningitis, and pneumonia. Phase II Telavancin versus Standard Therapy for Treatment of Complicated Skin and Soft-Tissue Infections due to Gram-Positive Bacteria (FAST 1 and FAST 2) and phase III [Assessment of Telavancin in Complicated Skin and Skin Structure Infections 1 (ATLAS 1 and ATLAS 2)] clinical trials have been conducted for evaluating telavancin’s efficacy and safety in cSSSIs.

Phase III clinical trials have been carried out for evaluating telavancin’s safety and efficacy in nosocomial pneumonia [Assessment of Telavancin for Treatment of Hospital acquired Pneumonia 1 and 2 (ATTAIN 1 and ATTAIN 2)].

A phase II randomized, double-blind, clinical trial has been carried out for evaluating telavancin’s safety and efficacy in uncomplicated S. aureus bacteremia [Telavancin for Treatment of Uncomplicated S. aureus Bacteremia (ASSURE)]. Pacemaker lead-related infective endocarditis due to a vancomycin intermediate S. aureus (VISA) strain (non-daptomycin susceptible) was successfully treated with parenteral telavancin for 8 weeks.

Telavancin extensively binds to serum albumin (~93%) and has a relatively small volume of distribution. Telavancin is not biotransformed by any cytochrome P450 microsomal enzymes and excreted mainly in the urine. Though well-tolerated, worrisome adverse effects, including renal dysfunction and QTc prolongation are of potential concern.

Given its extensive binding to plasma proteins, long half-life, and a long post-antibiotic effect, it represents a promising addition to the therapeutic armamentarium in combating infections caused by resistant Gram-positive pathogens, namely, MRSA.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5467880/pdf/10.1177_2049936117690501.pdf

July 11, 2017 at 4:04 pm

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