Tuesday, February 26, 2008

Prophylactic antibiotics given within 24 hours of surgery, compared with antibiotics given for 72 hours perioperatively increased rate of MRSA

Prophylactic antibiotics given within 24 hours of surgery, compared with antibiotics given for 72 hours perioperatively, increased the rate of methicillin-resistant Staphylococcus aureus isolated from surgical site infections

J Infect Chemother. 2008 Feb

Kusachi S, Sumiyama Y, Nagao J, Arima Y, Yoshida Y, Tanaka H, Nakamura Y, Saida Y, Watanabe M, Watanabe R, Sato J.Third Department of Surgery, Toho University Ohashi Medical Center Hospital, 2-17-6 Ohashi, Meguro-ku, Tokyo, 153-8515, Japan, kusachi@med.toho-u.ac.jp.

The purpose of this research was to find which method better prevented MRSA isolation from postoperative infection sites: the administration of postoperative infection control agents within 72 h of surgery, including the day of surgery, or the administration of these agents within 24 h of surgery. More than 3000 patients who underwent elective surgery of the digestive system were studied. Cefazolin or cefotiam was used as the prophylactic antibiotic. The number of patients, sex, age, clinical stage, incidence of surgical site infection (SSI), isolated bacteria, distal pancreatectomy with or without gastrectomy, the rate of laparoscopic surgery, and the rate of abdominoperineal resection (APR) were examined in a prospective controlled study over three time periods. There were no significant differences in the demographics of patients in the three periods. The duration of antibiotic administration was 96.1 +/- 11.2 h in period A, 18.2 +/- 2.7 h in period B, and 66.9 +/- 11.1 hours in period C (P less then 0.05). There was no significant difference in the incidence of SSI in the three periods. Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from the infectious site in 0.47% of patients in period A, and from 2.1% and 0.34% of patients in periods B and C, respectively, and the incidence of MRSA was significantly higher in period B as compared with periods A and C. The isolation rates of MRSA and methicillin-sensitive S. aureus (MSSA) were both significantly higher in period B patients. We concluded that the administration of prophylactic antibiotics within 24 h of surgery increased the rate of isolation of MRSA.


Saturday, February 23, 2008

Community-acquired methicillin-resistant Staphylococcus aureus: an emerging concern for physical therapists: Discussion.

Community-acquired methicillin-resistant Staphylococcus aureus: an emerging concern for physical therapists: Discussion.
Physiother Res Int. 2008 Feb

Levenhagen KM.
Department of Physical Therapy, Doisy College of Health Sciences, Saint Louis University, 3437 Caroline Mall, Room 1026, St. Louis, MO 63104, USA.

The Centers for Disease Control has identified community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) as an emerging worldwide public health risk. Healthcare professionals such as physical therapists can play an important role in the early detection, prevention and management of CA-MRSA. This discussion paper is a narrative overview of CA-MRSA's prevalence in at-risk groups, the distinguishing characteristics of hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) and CA-MRSA infections, and treatments for HA-MRSA and CA-MRSA. Using the Guide to Physical Therapist Practice as a framework, this paper describes physical therapists' role in the detection, prevention and management of CA-MRSA infections and their role in community education about CA-MRSA. Copyright (c) 2008 John Wiley & Sons, Ltd.

PMID: 18288766 [PubMed - as supplied by publisher]

Daptomycin: a new treatment for insidious infections due to gram-positive pathogens (MRSA)

Daptomycin: a new treatment for insidious infections due to gram-positive pathogens (MRSA)
February 2008

Cottagnoud P.
Department of Internal Medicine, Inselspital, Bern, Switzerland.

Daptomycin, a new lipopeptide antibiotic, is highly bactericidal against the majority of Grampositive human pathogens, including methicillinresistant (MRSA) and vancomycin-resistant enterococci. Its mechanism of action is unique resulting in the destruction of the membrane potential without lysing the cell wall. The mechanism of action of daptomycin, its antibacterial spectrum, the development of resistance and pre- and clinical studies are discussed in this review.

PMID: 18293118 [PubMed - in process]

Friday, February 22, 2008

Rapid Diagnostics for Methicillin-Resistant Staphylococcus aureus: Current Status.

Rapid Diagnostics for Methicillin-Resistant Staphylococcus aureus: Current Status.
Mol Diagn Ther. 2008

Carroll KC.
Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of healthcare- and community-associated infections, and its prevalence continues to increase. These infections are associated with morbidity and excessive mortality compared with infections caused by methicillin-susceptible S. aureus (MSSA). Numerous studies have cited the increased healthcare costs associated with MRSA infections. Infection control guidelines that combine active surveillance with aggressive patient management, such as patient isolation, decontamination, and other strategies, have been shown to reduce transmission and subsequent infections. The availability of rapid molecular diagnostics has strengthened infection control programs by providing results in hours rather than days, as the time required for culture-based methods. This review summarizes the current status of rapid diagnostic methods available for MRSA detection from nasal surveillance specimens, and assays available for rapid identification of MRSA from positive blood cultures containing Gram-positive cocci in clusters. Both amplification- and probe-based assays are highlighted and discussed in detail. Future technological advances are likely to see real-time assays that combine multiple gene targets for assessment of microbial identification, virulence detection, and mechanisms of resistance beyond mecA.

PMID: 18288879 [PubMed - in process]

Monday, February 18, 2008

USA300 MRSA may be sexually transmitted in MSM

USA300 MRSA may be sexually transmitted in MSM
Male–male sex should be considered a risk factor for multidrug-resistant USA300 MRSA infection, independent of previous infection.
by Jay LewisIDN Managing Editor

February 2008

Multidrug-resistant USA300 methicillin-resistant Staphylococcus aureus may be significantly more prevalent in men who have sex with men, compared with the general population, according to the results of a recent study. The researchers hypothesized that multidrug-resistant USA300 MRSA may be sexually transmitted in this population.

The researchers conducted a population-based survey in nine hospitals in San Francisco and a cross-sectional study in two outpatient clinics in San Francisco and Boston. The researchers reviewed patients’ data to determine annual incidence, spatial clustering and risk factors for multidrug-resistant USA300 MRSA.

The results showed that the overall incidence of multidrug-resistant USA300 MRSA infection in San Francisco was 26 cases per 100,000 people. Further analysis demonstrated that incidence rates were higher in ZIP codes with a higher percentage of male same-sex couples.
The researchers determined that male–male sex should be considered a risk factor for multidrug-resistant USA300 MRSA infection, independent of previous MRSA infection. This risk also appeared to be independent of HIV status.

Study limitations

The researchers stressed that there are several limitations to the study: it only examined the multidrug-resistant USA300 strain of MRSA and did not assess patients’ sexual behavior risks.

“Our study examined the rate of infection with multidrug-resistant USA300 MRSA, which is only a subset of the usual USA300 MRSA that is susceptible to multiple antibiotics,” Christopher Graber, MD, MPH, one of the study’s researchers and member of the infectious diseases section at the VA Greater Los Angeles Healthcare System, told Infectious Disease News. “We found that this multidrug-resistant clone seemed to be concentrated in the ZIP code corresponding to the Castro district when we examined its prevalence in isolates collected from a population-based study of MRSA in San Francisco in 2004-2005. There had been results of prior studies that described a high frequency of MRSA infection in MSM, so we undertook the clinic-based studies to see if patients self-identifying as MSM were experiencing infections due to this multidrug-resistant USA300 clone more than other populations, which ended up being the case.”

Graber said more information is needed to better understand how multidrug-resistant USA300 MRSA is transmitted and why it may be infecting MSM at an increased frequency. “The retrospective nature of our study did not allow us to systematically investigate how transmission of infection exactly occurred; it only allowed us to identify the presence of multidrug-resistant USA300 MRSA in the MSM population,” Graber said. “We already know that MRSA disease can be spread by close skin-to-skin contact, and we did find that a large number of patients with infection due to multidrug-resistant USA300 MRSA had infections in the buttock/genitoperineal areas; however, we can only make an epidemiologic association and cannot definitively specify a method of transmission.”

Media attention

The study results, which are published in the Feb. 19 issue of Annals of Internal Medicine, were made available on the journal’s website in mid-January.

After its online release, the study received much attention in the mainstream media, including stories garnering headlines cautioning about a “new gay disease” and “the new HIV.” However, experts are concerned that some of this media attention may have misled the general public about the risk for multidrug-resistant USA300 MRSA.

Graber said previous reports and studies have suggested heterosexual transmission of MRSA strains. The mainstream media may be misleading the public into thinking only MSM are at risk for infection with multidrug-resistant USA300 MRSA. “USA300 MRSA is already present in the general population, and it is reasonable to expect that multidrug-resistant USA300 MRSA will spread in the general population as well,” Graber said.

According to Graber, the spread of MRSA strains can be reduced if people maintain proper personal hygiene, including regular bathing and frequent handwashing. “Routine examination of the skin is also important to identify small cuts and abrasions that could serve as points of bacterial entry,” Graber said. “Any person who has an active skin infection should keep draining wounds covered and thoroughly wash or dispose of all material that comes into contact with the wound.”

To reduce the risk for sexual transmission of MRSA strains, people are encouraged to wash with soap and water after sex, particularly if their partners show signs of active skin infection.

For more information:

Diep B, Chambers H, Graber C, et al. Emergence of multidrug-resistant, community-associated, methicillin-resistant Staphylococcus aureus clone USA300 in men who have sex with men. Ann Intern Med. http://www.annals.org/cgi/content/full/0000605-200802190-00204v1.

Infectious Disease News

Saturday, February 16, 2008

Emergence of MRSA in positive blood cultures from patients with febrile neutropenia-a cause for concern.

Emergence of MRSA in positive blood cultures from patients with febrile neutropenia-a cause for concern.

Support Care Cancer. 2008 Feb 15

Morris PG, Hassan T, McNamara M, Hassan A, Wiig R, Grogan L, Breathnach OS, Smyth E, Humphreys H.
Department of Oncology, Beaumont Hospital, Dublin 9, Dublin, Ireland,

GOALS OF WORK: Febrile neutropenia (FN) causes considerable morbidity in patients on cytotoxic chemotherapy. Recently, there has been a trend towards fewer Gram-negative and more Gram-positive infections with increasing antibiotic resistance. To assess these patterns, data from a supra-regional cancer centre in Ireland were reviewed.

PATIENTS AND METHODS: A 5-year review of all positive blood cultures in patients undergoing anti-cancer chemotherapy was carried out.

MAIN RESULTS: Eight hundred and ninety-four patients were reviewed. The mean incidence of FN was 64.2 cases per year. Eight hundred and forty-six blood culture specimens were taken and 173 (20.4%) were culture positive. The isolated organisms were Gram positive (71.1%), Gram negative (27.8%) and fungal (1.1%). Of the Gram-positive organisms, 75.6% were staphylococci. Of these, 67.8% were coagulase-negative staphylococci and 30.1% were Staphylococci aureus. Amongst the S. aureus, 89.3% were methicillin-resistant (MRSA). Vancomycin-resistant enterococci were not identified as a cause of positive blood cultures.

CONCLUSIONS: Amongst patients with cancer who develop FN in our hospital, Gram-positive bacteria account for the largest proportion. The high proportion of MRSA as a cause of positive blood cultures is of concern.

PMID: 18274787 [PubMed - as supplied by publisher]

MRSA and the environment: implications for comprehensive control measures

MRSA and the environment: implications for comprehensive control measures

Eur J Clin Microbiol Infect Dis. 2008 Feb 14

N. Cimolai1, 2
Department of Pathology and Laboratory Medicine, Faculty of Medicine, The University of British Columbia, Vancouver, BC, V6H 3V4, Canada
Department of Pathology and Laboratory Medicine, Children’s and Women’s Centre of British Columbia, Vancouver, BC, V6H 3V4, Canada
Received: 28 September 2007 Accepted: 23 January 2008 Published online: 14 February 2008

Email: ncimolai@interchange.ubc.ca


Environmental contamination with methicillin-resistant Staphylococcus aureus (MRSA) is established soon after colonized or infected patients become resident. There are many studies that detail the mechanisms of spread and environmental survival of methicillin-susceptible Staphylococcus aureus (MSSA); this knowledge translates directly into the same findings for MRSA. The potential ubiquity of MRSA in a health-care setting poses challenges for decontamination. Whereas patients and medical staff are important sources for MRSA spread, the environmental burden may contribute significantly in various contexts. Effective control measures must therefore include consideration for MRSA in the environment.


Sunday, February 3, 2008

Mortality after infection with methicillin resistant Staphylococcus aureus (MRSA) diagnosed in the community

Mortality after infection with methicillin resistant Staphylococcus aureus (MRSA) diagnosed in the community
BMC Med. 2008 Jan 31

Delaney JA, Schneider-Lindner V, Brassard P, Suissa S.


Outbreak reports suggest that community-acquired Methicillin-resistant Staphylococcus aureus (MRSA) infections can be life-threatening. We conducted a population based cohort study to assess the magnitude of mortality associated with MRSA infections diagnosed in the community.


We used the United Kingdomas General Practice Research Database (GPRD) to form a cohort of all patients with MRSA diagnosed in the community from 2001 through 2004 and up to ten patients without an MRSA diagnosis. The latter were frequency-matched with the MRSA patients on age, GPRD practice, and diagnosis date. All patients were older than 18 years, had no hospitalization in the 2 years prior to cohort entry, and medical history information of at least 2 years prior to cohort entry. The cohort was followed up for one year and all deaths and hospitalizations were identified. Hazard ratios of all-cause mortality were estimated using the Cox proportional hazards model adjusted for patient characteristics.


The cohort included 1,439 patients diagnosed with MRSA and 14,090 patients with no MRSA diagnosis. Mean age at cohort entry was 70 years in both groups, while co-morbid conditions were more prevalent in the patients with MRSA. Within 1 year, 21.8% of MRSA patients died as compared with 5.0% of non-MRSA patients. The risk of death was increased in patients diagnosed with MRSA in the community (adjusted hazard ratio 4.1; 95% confidence interval: 3.5 to 4.7).


MRSA infections diagnosed in the community are associated with significant mortality in the year after diagnosis.

BMC Medicine