MRSA Infection

Staphylococcus aureus Colonization Among Household Contacts of Patients With Skin Infections

Staphylococcus aureus Colonization Among Household Contacts of Patients With Skin Infections: Risk Factors, Strain Discordance, and Complex Ecology.

Results. We enrolled 1162 persons (350 index patients and 812 household members). The most common infection isolate characteristic was ST8/SCCmec IV, PVL+ MRSA (USA300) (53%). S. aureus colonized 40% (137/350) of index patients and 50% (405/812) of household contacts. A nares-only survey would have missed 48% of S. aureus and 51% of MRSA colonized persons. Sixty-five percent of households had >1 S. aureus genetic background identified and 26% of MRSA isolates in household contacts were discordant with the index patients' infecting MRSA strain type. Factors independently associated (P < .05) with the index strain type colonizing household contacts were recent skin infection, recent cephalexin use, and USA300 genetic background. Conclusions. In our study population, USA300 MRSA appeared more transmissible among household members compared with other S. aureus genetic backgrounds. Strain distribution was complex; >1 S. aureus genetic background was present in many households. S. aureus decolonization strategies may need to address extra-nasal colonization and the consequences of eradicating S. aureus genetic backgrounds infrequently associated with infection.

Community MRSA entering Hospitals in India

BMC Microbiology | Abstract | al complexes and virulence factors of Staphylococcus aureus from several cities in India.

Molecular analyses of 68 S. aureus isolates from in and around Bengaluru and three other Indian cities have been carried out. Our strains fall into fifteen ST with all major clonal complexes (CC) present along with some minor ones. The dominant MRSA clones are ST22 and ST772 among healthy carriers and patients. We are reporting two methicillin sensitive S. aureus (MSSA) isolates belonging to ST291 (related to ST398 which is live stock associated), ST1208 (CC8), and ST672 as emerging MRSA clones in this study for the first time. Sixty nine percent of isolates carry Panton- Valentine Leucocidin genes (PVL) along with many other toxins. There is more diversity of ST among methicillin sensitive S. aureus than resistant ones. Microarray analysis of isolates belonging to different ST for the first time gives an insight into major toxins, virulence factors, adhesion and immune evasion factors present among the isolates in various parts of India. Conclusions S. aureus isolates reported in this study belong to a highly diverse group of ST and CC and we are reporting several new ST which have not been reported earlier along with factors influencing virulence and host pathogen interactions.

Probe into community MRSA in Glasgow

Probe into community superbugs | Evening Times.

GLASGOW health chiefs are to investigate the number of cases of superbug infections in the community. NHS Greater Glasgow and Clyde is to monitor cases of C.diff caught outside hospitals and S.aureus, the bacterium that causes MRSA. The board said while hospital infection rates are now at their lowest recorded levels, attempts to tackle community infections had not been as successful.

Community-onset Staph infections - Some worse than MRSA

Illness severity in community-onset invasive Staphylococcus aureus infection and the presence of virulence genes.

Results 57 cMRSA and 50 cMSSA infections were analyzed. Ten clones caused 82 (77%) of these infections and had an ISS calculated. The enterotoxin gene cluster (egc), and the collagen adhesin (cna) gene were found in four of the five highest ranked clones (ST47-MSSA, ST30-MRSA-IV[2B], ST45-MSSA and ST22-MRSA-IV[2B]) compared with none and one of the lowest five ranked clones. cMSSA clones caused more severe infection than cMRSA clones. The lukF/lukS Panton-Valentine leukocidin (PVL) genes did not directly correlate with the ISS, being present in the 2nd, 4th and 10th most virulent clones. Conclusions The clinical severity of invasive cMRSA and cMSSA infection is likely to be attributable to the isolates’ entire genotype rather than a single putative virulence determinant such as PVL.

Trends in Staph infections in USA hospital

Trends and Characteristics of Culture-Confirmed Staphylococcus aureus Infections in a Large U.S. Integrated Health Care Organization.

Results. The percent of SA isolates that were MRSA increased from 9% to 20% between 1998 and 2001, from 25% to 49% between 2002 and 2005, and decreased from 49% to 43% between 2006 and 2009. The increase in MRSA was seen in blood and in other bacteriological specimens, and occurred in all ages and race/ethnicity groups, though most pronounced in persons aged 18-<50 years and African-Americans. Hospital-onset infections were the most likely to be MRSA (Odds Ratio (OR): 1.58, Confidence Interval (CI): 1.46 to 1.70, compared to community-associated cases), but the largest increase in MRSA was among community-associated infections. Isolates from African-Americans (OR: 1.73, CI: 1.64 to 1.82) and Hispanics (OR: 1.11, CI: 1.06 to 1.16) were more likely to be MRSA, compared to whites. Conclusions. After substantial increases between 1998 and 2005 in the proportion of SA isolates that were MRSA, the proportion decreased between 2006 and 2009. Hospital-onset SA infections are disproportionately MRSA, as are those among African-Americans.

Non Livestock MRSA ST398 'sticks to skin'

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One example of the scientific challenge emerged last month. Researchers from Columbia University Medical Center, NIH, and St. George’s University of London detailed how methicillin-susceptible S. aureus (MSSA) clone ST398-NM has emerged as a significant cause of community-associated infections in humans in the U.S., Europe, and China. Based on samples from 332 Manhattan households, scientists determined ST398-NM efficiently transmits from person to person in part because it adheres well to human skin.

Community MRSA - It keeps coming back for some patients

Where We Are With Community-Associated Staphylococcus aureus Prevention—And in the Meantime, What Do We Tell Our Patients?.

One notable aspect of CA-MRSA skin infections is their predilection to cause subsequent disease. Recurrent SSTIs are frequently encountered in patients with community-associated S. aureus and CA-MRSA [1], and recurrence rates exceeding 50% have been described in selected populations [5]. Unfortunately, there are few data to guide clinicians and patients on optimal methods for prevention. In this issue of Clinical Infectious Diseases, Fritz et al [6] present results of a randomized clinical trial on prevention of community-associated S. aureus SSTI infection. The investigators randomized children with S. aureus infection plus S. aureus colonization in the nares, axilla, or inguinal folds into a 5-day decolonization regimen that targeted either the infected child alone or the entire household. The investigators exploited the knowledge that many households’ members are also colonized with the infecting isolate [7] and thus may serve as reservoirs for pathogenic S. aureus strains.

Scientists Investigate Rogue Strain of MRSA ST398 spreading in Community

Scientists Investigate a Newly Emerging Staph Strain.

A methicillin-resistant S. aureus (MRSA) strain known as livestock-associated (LA)-ST398 is a cause of severe infections in people in Europe who have close contact with swine, but the bacterium does not transmit well from person to person. More recently, a variant of LA-ST398 that presently is susceptible to methicillin has emerged as a significant cause of community-associated infections in several countries, including the United States, Canada and China. The new strain primarily infects the skin and soft tissue, but it can cause more severe disease. Based on samples from 332 households in northern Manhattan, New York, scientists have determined that this new strain, named ST398-NM, efficiently transmits from person to person—in contrast to the transmission characteristics of the livestock-associated strain. By analyzing and comparing the genomes of LA-ST398 and ST398-NM, the study, led by Anne-Catrin Uhlemann, MD, PhD, at Columbia, charted several ways in which the bacterium has adapted to its hosts. For example, they learned that the human-adapted strain (ST398-NM) contains human-specific immune evasion genes, whereas the livestock-adapted strain does not. They also found that ST398-NM adheres well to human skin, thus increasing its ability to colonize and infect people.

HIV & AIDS Information :: 'Social networks' may explain high prevalence of MRSA colonization seen in patients with HIV

HIV & AIDS Information :: 'Social networks' may explain high prevalence of MRSA colonization seen in patients with HIV.

Infection with HIV per se does not increase the risk of colonisation with community-associated MRSA, according to US research published in the online edition of Clinical Infectious Diseases. The investigators found that prevalence of nasal colonisation with community-associated MRSA (methicillin-resistant Staphylococcus aureus) was significantly higher in HIV-positive patients compared to HIV-negative patients. However, they also found a hierarchy of risk among the HIV-positive patients. Moreover, after controlling for factors such as imprisonment and area of residence, infection with HIV did not have a significant association with MRSA colonisation. “Community exposures may be more important for predicting MRSA colonization than HIV status in certain groups,” comment the authors. Earlier research by the same investigators showed that HIV-positive patients had a six-fold higher risk of community-acquired MRSA skin and soft tissue infections compared to HIV-negative individuals. It is unclear why HIV-positive patients have an increased risk of the infection. Immune suppression and extensive use of antibiotics may be contributory factors.

Why Community MRSA Will Dominate

Methicillin Resistance Reduces the Virulence of Healthcare-Associated Methicillin-Resistant Staphylococcus aureus by Interfering With the agr Quorum Sensing System.

In our study of one of the major healthcare-associated MRSA (HA-MRSA) clones, we show that expression of the gene responsible for conferring methicillin resistance (mecA) is also directly responsible for reducing the ability of HA-MRSA to secrete cytolytic toxins. We show that resistance to methicillin induces changes in the cell wall, which affects the bacteria's agr quorum sensing system. This leads to reduced toxin expression and, as a consequence, reduced virulence in a murine model of sepsis. This diminished capacity to cause infection may explain the inability of HA-MRSA to move into the community and help us understand the recent emergence of community-associated MRSA (CA-MRSA). CA-MRSA typically express less penicillin-binding protein 2a (encoded by mecA), allowing them to maintain full virulence and succeed in the community environment.

Commercially distributed meat and community MRSA

Commercially distributed meat as a potential vehicle for community-acquired methicillin-resistant Staphylococcus aureus.

We examined the distribution of MRSAs in commercially distributed raw meat samples (n = 197) and diarrheal stool samples of outpatients (n = 1287) that were collected in Oita Prefecture, Japan, between 2003 and 2009 for routine legal inspections. Fourteen MRSA strains were isolated from 3 meat and 11 stool samples. Among these, 7 isolates from 3 meat and 4 stool samples exhibited the same epidemiological marker profiles [coagulase type III, staphylococcal enterotoxin C, SCCmec type IV, ST8, spa type 606 (t1767), and TSST-1 producing type]. Furthermore, of the 7 strains, 3 isolates from 2 meat and 1 stool samples collected in 2007 exhibited completely identical characteristics with respect to phage ORF typing, pulsed-field gel electrophoresis, and drug susceptibility profiles. The results suggest that commercially distributed meat could play a role in the prevalence of CA-MRSA in the community.

Vigilance urged against community-associated MRSA

Vigilance urged against community-associated MRSA.

The appeal was made following the CHP's investigation into a confirmed case of invasive CA-MRSA involving a 26-year-old woman living in Southern District. The woman, with good past health, presented with right calf pain on November 15. She consulted the Accident and Emergency Department of Pamela Youde Nethersole Eastern Hospital the next day and was found to have an abscess on her right calf. She was admitted to hospital and an operation was done on November 18 to remove the abscess. The patient is currently in stable condition in hospital. Her blood culture grew CA-MRSA. She has no recent travel history. Her home contacts had no symptoms of CA-MRSA infection.

Chronic MRSA on the rise

Minor 'nuisance' cases of MRSA on the rise - South Florida Sun-Sentinel.com.

"It's more disfiguring than anything else," said Dr. Latha Srinath, a specialist in Boynton Beach. "These are young people coming in with multiple abscesses and infections that don't go away after repeated treatments with antibiotics. At any given day at my offices, I have two or three new referrals, which is a lot." The cases involve "community-acquired" MRSA that lives on the skin and nasal passages, spreading through skin-to-skin contact and fluids such as sweat. Patients rarely need to be hospitalized, but many come back for a second or third time when drugs do not clear up the infection, said Dr. Nabil El Sanadi, chief of four ERs at the tax-assisted North Broward Hospital District.

Community MRSA and HIV

BioMed Central | Full text | Community-associated Methicillin-resistant Staphylococcus aureus Bacteremia and Endocarditis among HIV Patients: a cohort study.

Results Among 131 episodes of S. aureus bacteremia, 85 (66%) were MRSA of which 47 (54%) were CA-MRSA. Sixty-three patients (48%) developed endocarditis and 10 patients (8%) died in the hospital on the index admission Patients with CA-MRSA were significantly more likely to develop endocarditis (OR = 2.73, 95% CI = 1.30, 5.71). No other variables including comorbid conditions, current receipt of antiretroviral therapy, pre-culture severity of illness, or CD4 count were significantly associated with endocarditis and none were associated with in-hospital mortality. Conclusions CA-MRSA was significantly associated with an increased incidence of endocarditis in this cohort of HIV patients with MRSA bacteremia. In populations such as these, in which the prevalence of intravenous drug use and probability of endocarditis are both high, efforts must be made for early detection, which may improve treatment outcomes.

Community MRSA a challenge for HIV Patients s

Hopkins Nurse Researcher Studies Control of Secondary Infections in HIV-Positive Patients.

The biggest issue for HIV/AIDS-affected patients, Farley says, is the immune response a CA-MRSA infection prompts. The viral load spikes when the body begins to fight CA-MRSA. “We wanted to look at how the bacteria evolved and whether patients had it on different parts of the body,” Farley says. “It’s important to know if a patient is a carrier or has been colonized by the strain especially if they start to develop multiple skin and soft tissue infections.” Understanding CA-MRSA’s genetic make-up can help create an intervention that prevents bacterial infection between persons or within households, Farley says. A Johns Hopkins Clinical Research Scholars Award funded the study.

Illegal tattoo shops spread MRSA

Investigation uncovers illegal tattoo shops operating in Northeast Ohio.

Dangerous skin infections linked to illegal tattooing Illegal tattooing has also been linked to outbreaks of MRSA, an antibiotic–resistant staph infection. MRSA can resemble red pimples or boils that can turn into pus-filled abscesses, according to Dr. Elma Baron, a dermatologist at University Hospitals Case Medical Center in Cleveland. In April 2005, Ohio Department of Health officials documented 12 cases of MRSA linked to illegal tattooing in the Toledo area. In January 2009, three cases were linked to illegal tattooing in Logan County. Ohio health officials have also documented two MRSA outbreaks linked to legal tattoo shops. In May 2005, seven cases were documented in Highland County. In January 2011, six cases were documented in Jackson County. Dr. Baron said she regularly treats patients who have contracted MRSA and other skin infections after getting tattooed. “It’s pretty common, especially for the young people who are getting more and more tattoos,” she said. Rising popularity sparks demand for illegal shops. Grisez blames the rising popularity of tattooing for the rise in illegally operated shops.

Next phase of MRSA study rolled out to Washington's firefighters

Next phase of MRSA study rolled out to Washington's firefighters | KING5.com Seattle.

The University of Washington is beginning phase two of a health study involving the state's firefighters hoping to see how widespread MRSA bacteria really is. The study has already attracted international attention about the medical and health risks of being a firefighter, and could lead to listing MRSA as one more job related health threat facing the nation's firefighters. The initial study conducted a year ago found one group of Snohomish County firefighters tested positive for MRSA in their systems at a rate 10 to 20 times that of the general public.

Management of MRSA in Community Clinics

Management of Skin and Soft Tissue Infections in Community Practice Before and After Implementing a “Best Practice” Approach: An Iowa Research Network (IRENE) Intervention Study.

Results: Three hundred sixty-eight forms (244 preintervention and 124 postintervention) were returned; 216 (89%) preintervention forms and 118 (95%) postintervention forms were usable. Multivariable logistic regression models found statistically significant and independent factors associated with MRSA coverage at the initial visit included being in the postintervention rather than the preintervention group, having an abscess component compared with cellulitis alone, having a culture sent, being prescribed two or fewer antibiotics, and not being hospitalized. Conclusions: The CDC algorithm was feasible for offices to use. Following a discussion of SSTI management in the outpatient setting, use of MRSA coverage increased both initially and overall. Thus, involving clinicians in a discussion about guidelines rather than simply providing guidelines or a didactic session may be a useful way to change physician practices.

Community MRSA entering hospitals in UAE

Change in meticillin-resistant Staphylococcus aureus clones at a tertiary care hospital in the United Arab Emirates over a 5-year period -- Sonnevend et al. -- Journal of Clinical Pathology.

Aims Meticillin-resistant Staphylococcus aureus (MRSA) strains isolated in Tawam Hospital, a tertiary care hospital in the United Arab Emirates, were examined in order to understand the reasons for a doubling of its incidence between 2003 and 2008 while maintaining the same infection control measures. Methods All consecutive non-duplicate clinically relevant MRSA isolates recovered between January and December 2003 and between May and October 2008 were studied. The antibiotic susceptibility, pulsed field gel electrophoresis, toxin gene, staphylococcal cassette chromosome mec (SCCmec), spa, agr and multilocus sequence types of the strains were tested. Results In 2003, typical healthcare-associated (HA-MRSA) genotypes (ST239-MRSA-III, ST22-MRSA-IV and ST5-MRSA-II) represented the majority (61.5%) of the isolates. By 2008 this pattern had changed and clonal types considered as community-associated (CA) MRSA comprised 73.1% of the strains with ST80-MRSA-IV, ST5-MRSA-IV and ST1-MRSA with non-typable SCCmec types being the most frequent. However, further epidemiological investigations showed that only one-third of the CA-MRSA infections were actually acquired in the community, indicating that CA-MRSA clones have entered and spread within the hospital. Conclusions The emergence of CA-MRSA clones with subsequent entry to and spread within the hospital has contributed to the increasing incidence of MRSA observed in Tawam Hospital and probably also in other hospitals in the UAE.

Emergence of community-acquired MRSA in India

Nine years' review on preseptal and orbital cellulitis and emergence of community-acquired methicillin-resistant Staphylococus aureus in a tertiary hospital in India Pandian DG, Babu RK, Chaitra A, Anjali A, Rao VA, Srinivasan R - Indian J Ophthalmol.

Context: Preseptal cellulitis is the commonest orbital disease which frequently needs to be differentiated from orbital cellulitis. Prompt diagnosis and treatment with appropriate antibiotics can prevent vision loss and life-threatening complications of orbital cellulitis. Aims: To describe the clinical profile of cases with preseptal and orbital cellulitis admitted to a tertiary care hospital during a period of nine years. The causative organisms and the clinical outcome were analyzed. Settings and Design : Retrospective descriptive case study done in a tertiary care hospital in South India. Material and Methods: The in-patient records of patients with preseptal and orbital cellulitis were reviewed from 1998 to 2006. The factors reviewed included ocular findings aiding in the distinction of the two clinical conditions, the duration of symptoms, the duration of hospital stay, microbiological culture report of pus or wound swab, blood culture, drugs used for treatment, the response to therapy and complications. Statistical Analysis Used: Descriptive analysis. Results: One hundred and ten cases, 77 patients with preseptal cellulitis and 33 patients with orbital cellulitis were reviewed. Five percent of children and 21% of adults presented with cutaneous anthrax contributing to preseptal cellulitis. Thirty-nine percent cases with orbital cellulitis were caused by methicillin-resistant Staphylococcus aureus (MRSA). Conclusions: This study has helped in identifying organisms which cause orbital infections, especially community-acquired MRSA. It indicates the need for modifying our empirical antimicrobial therapy, especially in orbital cellulitis.