Archive for January 11, 2016

Comparison of methicillin-resistant and methicillin-sensitive Staphylococcus aureus strains isolated from a tertiary hospital in Terengganu, Malaysia.

Jpn J Infect Dis. 2012;65(6):502-9.

Lim KT1, Yeo CC, Suhaili Z, Thong KL.

Author information

1Microbiology Division, Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.

Abstract

Staphylococcus aureus is a persistent human pathogen responsible for a variety of infections ranging from soft-tissue infections to bacteremia. The objective of this study was to determine genetic relatedness between methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) strains. We isolated 35 MRSA and 21 MSSA strains from sporadic cases at the main tertiary hospital in Terengganu, Malaysia, screening them for the presence of virulence genes. Their genetic relatedness was determined by accessory gene regulator (agr) types, PCR-restriction fragment length polymorphism (RFLP) of the coa gene, pulsed-field gel electrophoresis (PFGE), S. aureus protein A (spa), and multilocus-sequence typing (MLST). We found that 57% of MRSA and 43% of MSSA strains harbored enterotoxin genes. The majority (87.5%) of the strains were agr type I. PCR-RFLP and PFGE genotyping of the coa gene revealed that MRSA strains were genetically related, whereas MSSA strains had higher heterogeneity. The combined genotype, MLST-spa type ST239-t037, was shared among MRSA and MSSA strains, indicating that MRSA strains could have evolved from MSSA strains. Two combined MLST-spa types were present in MRSA strains, whereas 7 different MLST-spa types were detected in MSSA strains, including 2 combined types (ST779-t878 and ST1179-t267) that have not been reported in Malaysia. In conclusion, enterotoxin genes were more prevalent in MRSA than in MSSA strains in the Terengganu hospital. The MSSA strains were genetically more diverse than the MRSA strains.

PDF

https://www.jstage.jst.go.jp/article/yoken/65/6/65_502/_pdf

Advertisements

January 11, 2016 at 9:01 am

Case fatality ratio and mortality rate trends of community-onset Staphylococcus aureus bacteraemia.

Clin Microbiol Infect. 2014 Oct;20(10):O630-2.

Tom S1, Galbraith JC, Valiquette L, Jacobsson G, Collignon P, Schønheyder HC, Søgaard M, Kennedy KJ, Knudsen JD, Ostergaard C, Lyytikäinen O, Laupland KB; International Bacteraemia Surveillance Collaborative.

Collaborators (21)

Author information

1University of Calgary, Calgary, AB, Canada.

Abstract

Lethal outcomes can be expressed as a case fatality ratio (CFR) or as a mortality rate per 100 000 population per year (MR). Population surveillance for community-onset methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus bacteraemia was conducted in Canada, Australia, Sweden and Denmark to evaluate 30-day CFR and MR trends between 2000 and 2008. The CFR was 20.3% (MSSA 20.2%, MRSA 22.3%) and MR was 3.4 (MSSA 3.1, MRSA 0.3) per 100 000 per year. Although MSSA CFR was stable the MSSA MR increased; MRSA CFR decreased while its MR remained low during the study. Community-onset S. aureus bacteraemia, particularly MSSA, is associated with major disease burden. This study highlights complementary information provided by evaluating both CFR and MR.

PDF

http://www.clinicalmicrobiologyandinfection.com/article/S1198-743X(14)65398-2/pdf

January 11, 2016 at 9:00 am

Improved outcome with early rifampicin combination treatment in methicillin-sensitive Staphylococcus aureus bacteraemia with a deep infection focus – a retrospective cohort study.

PLoS One. 2015 Apr 13;10(4):e0122824.

Forsblom E1, Ruotsalainen E1, Järvinen A1.

Author information

1Division of Infectious Diseases, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland.

Abstract

INTRODUCTION:

Rifampicin has been used as adjunctive therapy in Staphylococcus aureus bacteraemia (SAB) with a deep infection focus. However, data for prognostic impact of rifampicin therapy is unestablished including the optimal initiation time point. We studied the impact of rifampicin therapy and the optimal initiation time for rifampicin treatment on prognosis in methicillin-sensitive S. aureus bacteraemia with a deep infection.

METHODS:

Retrospective, multicentre study in Finland including 357 SAB patients with a deep infection focus. Patients with alcoholism, liver disease or patients who died within 3 days were excluded. Patients were categorised according to duration of rifampicin therapy and according to whether rifampicin was initiated early (within 7 days) or late (7 days after) after the positive blood cultures. Primary end point was 90 days mortality.

RESULTS:

Twenty-seven percent of patients received no rifampicin therapy, 14% received rifampicin for 1-13 days whereas 59% received rifampicin ≥14 days. The 90 day mortality was; 26% for patients treated without rifampicin, 16% for rifampicin therapy of any length and 10% for early onset rifampicin therapy ≥14 days. Lack of rifampicin therapy increased (OR 1.89, p=0.026), rifampicin of any duration decreased (OR 0.53, p=0.026) and rifampicin therapy ≥14 days with early onset lowered the risk for a fatal outcome (OR 0.33, p<0.01) during 90 days follow-up.

CONCLUSION:

Rifampicin adjunctive therapy for at least 14 days and initiated within 7 days of positive blood culture associated with improved outcome among SAB patients with a deep infection.

PDF

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4395220/pdf/pone.0122824.pdf

January 11, 2016 at 8:58 am

A 1,000-Year-Old Antimicrobial Remedy with Antistaphylococcal Activity.

MBio. 2015 Aug 11;6(4):e01129.

Harrison F1, Roberts AE2, Gabrilska R3, Rumbaugh KP3, Lee C4, Diggle SP1.

Author information

1Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom freya.andersdottir@gmail.com steve.diggle@nottingham.ac.uk

2Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom.

3Department of Surgery, Texas Tech University Health Sciences Center, School of Medicine, Lubbock, Texas, USA.

4School of English and Centre for the Study of the Viking Age, University of Nottingham, University Park, Nottingham, United Kingdom.

Abstract

Plant-derived compounds and other natural substances are a rich potential source of compounds that kill or attenuate pathogens that are resistant to current antibiotics. Medieval societies used a range of these natural substances to treat conditions clearly recognizable to the modern eye as microbial infections, and there has been much debate over the likely efficacy of these treatments. Our interdisciplinary team, comprising researchers from both sciences and humanities, identified and reconstructed a potential remedy for Staphylococcus aureus infection from a 10th century Anglo-Saxon leechbook. The remedy repeatedly killed established S. aureus biofilms in an in vitro model of soft tissue infection and killed methicillin-resistant S. aureus (MRSA) in a mouse chronic wound model. While the remedy contained several ingredients that are individually known to have some antibacterial activity, full efficacy required the combined action of several ingredients, highlighting the scholarship of premodern doctors and the potential of ancient texts as a source of new antimicrobial agents.

IMPORTANCE:

While the antibiotic potential of some materials used in historical medicine has been demonstrated, empirical tests of entire remedies are scarce. This is an important omission, because the efficacy of “ancientbiotics” could rely on the combined activity of their various ingredients. This would lead us to underestimate their efficacy and, by extension, the scholarship of premodern doctors. It could also help us to understand why some natural compounds that show antibacterial promise in the laboratory fail to yield positive results in clinical trials. We have reconstructed a 1,000-year-old remedy which kills the bacteria it was designed to treat and have shown that this activity relies on the combined activity of several antimicrobial ingredients. Our results highlight (i) the scholarship and rational methodology of premodern medical professionals and (ii) the untapped potential of premodern remedies for yielding novel therapeutics at a time when new antibiotics are desperately needed.

PDF

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4542191/pdf/mBio.01129-15.pdf

January 11, 2016 at 8:56 am


Calendar

January 2016
M T W T F S S
« Dec   Feb »
 123
45678910
11121314151617
18192021222324
25262728293031

Posts by Month

Posts by Category