Posts filed under ‘BIOFILM – BIOPELICULAS’

Staphylococcus aureus Bacteremia and Endocarditis: Making an Impact on Outcomes: The Role of the Patient and the Organism

Infectious Diseases in Clinical Practice July 2011 V.19 N.4 P.238-242

NFID Clinical Updates

Weinstein, Robert A.

Three scientific approaches to infectious disease-case series, epidemiologic investigation, and molecular analysis-have aided researchers in understanding the evolution of pathogen activity.

Four eras of pathogen activity have occurred from 1920 to the present (streptococcus, staphylococci, gram-negative rods, and multidrug-resistant organisms).

The emergence of health care-associated and community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) infections has resulted in the blurred distinction among the entities.

In addition, there are several virulence factors that contribute significantly to the pathogenicity of the organism, and single nucleotide polymorphisms (SNPs) play an important role in determining an individual’s response to infection.

Health outcomes are significantly worse in MRSA patients compared with uninfected patients or those infected with methicillin-susceptible S. aureus (MSSA).

Ongoing molecular research will continue to elucidate mechanisms associated with virulence of MRSA.

FULL TEXT

https://journals.lww.com/infectdis/Fulltext/2011/07000/Staphylococcus_aureus_Bacteremia_and_Endocarditis_.2.aspx

PDF (CLIC en PDF)

Advertisements

December 7, 2018 at 9:30 am

Improving the Diagnosis of Orthopedic Implant-Associated Infections: Optimizing the Use of Tools Already in the Box

Clin. Microbiol. December 2018 V.56 N.12

Shawn Vasoo

With the increasing number of prosthetic joints replaced annually worldwide, orthopedic implant-associated infections (OIAI) present a considerable burden. Accurate diagnostics are required to optimize surgical and antimicrobial therapy. Sonication fluid cultures have been shown in multiple studies to improve the microbiological yield of OIAIs, but uptake of sonication has not been widespread in many routine clinical microbiology laboratories. In this issue, M. Dudareva and colleagues (J Clin Microbiol 56:e00688-18, 2018, https://doi.org/10.1128/JCM.00688-18) describe their unit’s experience with OIAI diagnosis using periprosthetic tissue inoculated into an automated blood culture system and sonication fluid culture.

FULL TEXT

https://jcm.asm.org/content/56/12/e01379-18?etoc=

PDF

https://jcm.asm.org/content/jcm/56/12/e01379-18.full.pdf

 

 

Clin. Microbiol. December 2018 V.56 N.12

Sonication versus Tissue Sampling for Diagnosis of Prosthetic Joint and Other Orthopedic Device-Related Infections

Maria Dudareva, Lucinda Barrett, Mel Figtree, Matthew Scarborough, Masanori Watanabe, Robert Newnham, Rachael Wallis, Sarah Oakley, Ben Kendrick, David Stubbs, Martin A. McNally, Philip Bejon, Bridget A. Atkins, Adrian Taylor and Andrew J. Brent

Current guidelines recommend collection of multiple tissue samples for diagnosis of prosthetic joint infections (PJI). Sonication of explanted devices has been proposed as a potentially simpler alternative; however, reported microbiological yield varies. We evaluated sonication for diagnosis of PJI and other orthopedic device-related infections (DRI) at the Oxford Bone Infection Unit between October 2012 and August 2016. We compared the performance of paired tissue and sonication cultures against a “gold standard” of published clinical and composite clinical and microbiological definitions of infection. We analyzed explanted devices and a median of five tissue specimens from 505 procedures. Among clinically infected cases the sensitivity of tissue and sonication culture was 69% (95% confidence interval, 63 to 75) and 57% (50 to 63), respectively (P < 0.0001). Tissue culture was more sensitive than sonication for both PJI and other DRI, irrespective of the infection definition used. Tissue culture yield was higher for all subgroups except less virulent infections, among which tissue and sonication culture yield were similar. The combined sensitivity of tissue and sonication culture was 76% (70 to 81) and increased with the number of tissue specimens obtained. Tissue culture specificity was 97% (94 to 99), compared with 94% (90 to 97) for sonication (P = 0.052) and 93% (89 to 96) for the two methods combined. Tissue culture is more sensitive and may be more specific than sonication for diagnosis of orthopedic DRI in our setting. Variable methodology and case mix may explain reported differences between centers in the relative yield of tissue and sonication culture. Culture yield was highest for both methods combined.

FULL TEXT

https://jcm.asm.org/content/56/12/e00688-18?etoc=

PDF

https://jcm.asm.org/content/jcm/56/12/e00688-18.full.pdf

November 28, 2018 at 3:12 pm

Ecological Analyses of Mycobacteria in Showerhead Biofilms and Their Relevance to Human Health

mBio 2018 September/October 2018 V.9 N.5 P.e01614-18

Matthew J. Gebert, Manuel Delgado-Baquerizo, Angela M. Oliverio, Tara M. Webster, Lauren M. Nichols, Jennifer R. Honda, Edward D. Chan, Jennifer Adjemian, Robert R. Dunn, Noah Fierer

Bacteria within the genus Mycobacterium can be abundant in showerheads, and the inhalation of aerosolized mycobacteria while showering has been implicated as a mode of transmission in nontuberculous mycobacterial (NTM) lung infections.

Despite their importance, the diversity, distributions, and environmental predictors of showerhead-associated mycobacteria remain largely unresolved.

To address these knowledge gaps, we worked with citizen scientists to collect showerhead biofilm samples and associated water chemistry data from 656 households located across the United States and Europe.

Our cultivation-independent analyses revealed that the genus Mycobacterium was consistently the most abundant genus of bacteria detected in residential showerheads, and yet mycobacterial diversity and abundances were highly variable.

Mycobacteria were far more abundant, on average, in showerheads receiving municipal water than in those receiving well water and in U.S. households than in European households, patterns that are likely driven by differences in the use of chlorine disinfectants.

Moreover, we found that water source, water chemistry, and household location also influenced the prevalence of specific mycobacterial lineages detected in showerheads.

We identified geographic regions within the United States where showerheads have particularly high abundances of potentially pathogenic lineages of mycobacteria, and these “hot spots” generally overlapped those regions where NTM lung disease is most prevalent. Together, these results emphasize the public health relevance of mycobacteria in showerhead biofilms.

They further demonstrate that mycobacterial distributions in showerhead biofilms are often predictable from household location and water chemistry, knowledge that advances our understanding of NTM transmission dynamics and the development of strategies to reduce exposures to these emerging pathogens.

FULL TEXT

https://mbio.asm.org/content/9/5/e01614-18

PDF

https://mbio.asm.org/content/mbio/9/5/e01614-18.full.pdf

November 9, 2018 at 8:14 am

NEUMONÍA ASOCIADA A VENTILACIÓN MECÁNICA. ACTUALIZACIÓN Y RECOMENDACIONES INTER-SOCIEDADES, SOCIEDAD ARGENTINA DE INFECTOLOGÍA – SOCIEDAD ARGENTINA DE TERAPIA INTENSIVA

Medicina (B Aires). 2018;78(2):99-106.

Pneumonia associated with mechanical ventilation. Update and recommendations inter- Societies SADI-SATI.

[Article in Spanish]

Cornistein W1, Colque ÁM2, Staneloni MI3, Monserrat Lloria M4, Lares M5, González AL5, Fernández Garcés A6, Carbone E7.

Author information

1 Hospital General de Agudos Dr. Cosme Argerich, Hospital Universitario Austral, Buenos Aires, Argentina. E-mail: wandacornistein@gmail.com.

2 Complejo Médico Churruca Visca, Buenos Aires, Argentina.

3 Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.

4 Hospital Prof. Alejandro Posadas, Buenos Aires, Argentina.

5 Hospital Interzonal General de Agudos San Martín de La Plata, Argentina.

6 Clínica AMEBPBA (Mutual de Empleados del Banco de la Provincia de Buenos Aires), Argentina.

7 Hospital Aeronáutico Central, Buenos Aires, Argentina.

Abstract

Representatives of the Argentine Society of Infectious Diseases (SADI) and the Argentine Society of Intensive Therapy (SATI) worked together on the development of specific recommendations for the diagnosis, treatment and prevention of ventilator-associated pneumonia (VAP). The methodology used was the analysis of the literature published in the last 15 years, complemented with the opinion of experts and local data. This document aims to offer basic tools to optimize diagnosis based on clinical and microbiological criteria, orientation in empirical and targeted antibiotic schemes, news on posology and administration of antibiotics in critical patients and to promote effective measures to reduce the risk of VAP. It also offers a diagnostic and treatment algorithm and considerations on inhaled antibiotics. The joint work of both societies -infectious diseases and intensive care- highlights the concern for the management of VAP and the importance of ensuring improvement in daily practices. This guideline established recommendations to optimize the diagnosis, treatment and prevention of VAP in order to reduce morbidity and mortality, days of hospitalization, costs and resistance to antibiotics due to misuse of antimicrobials.

PDF

http://www.medicinabuenosaires.com/PMID/29659359.pdf

November 3, 2018 at 10:43 am

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.

Abstract

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.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5427689/pdf/TOMICROJ-11-53.pdf

 

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. rld8@cdc.gov

Abstract

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.

PDF

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC118068/pdf/0012.pdf

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. rld8@cdc.gov

Abstract

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.

FULL TEXT

https://academic.oup.com/cid/article/33/8/1387/347551

PDF (CLIC en PDF)

 

October 14, 2018 at 10:39 am

Older Posts


Calendar

December 2018
M T W T F S S
« Nov    
 12
3456789
10111213141516
17181920212223
24252627282930
31  

Posts by Month

Posts by Category