MRSA Infection

Why nasal decolonization may not work for some

Controversies in Hospital Infection Prevention: Staph: It's deeper than you think.

An antibody stain against S. aureus was applied to visualize the site of colonization. There were two important findings: (1) colonization only occurred distally in the stratified squamous epithelium (i.e., there was no colonization of the more proximal ciliated mucosa; and (2) in 6/9 cadavers, staph organisms were visualized in the hair follicle shaft, and in 2 the bacteria were visualized deep in the follicle. The presence of S. aureus deep in the hair follicle may explain why some patients do not decolonize or recolonize after decolonization with mupirocin since the drug may not be able to penetrate that deeply.

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Coventry and Warwickshire hospitals to screen emergency patients for superbug

Coventry Telegraph - News - North Warwickshire News - Coventry and Warwickshire hospitals to screen emergency patients for superbug.

COVENTRY and Warwickshire’s hospitals are stepping up their fight against MRSA by screening emergency patients for the superbug. Every patient who goes into hospital for a planned operation is already checked to make sure they are not carrying the bug on their skin. But now University Hospital, Coventry, Warwick and George Eliot hospitals are set to screen all patients who are admitted through A&E as well. The Department of Health wants all hospitals to start doing this by the end of the year, but our local hospitals have decided to roll out the scheme three months ahead of schedule. Jill Foster, chief nursing officer at University Hospital, said: “We know members of the public are rightly concerned about hospital infections and, although we have one of the lowest infection rates in the West Midlands, we are keen to reduce this even further.”

Probing the Genetics of VRSA to Find Drug Targets

Molecular Basis of Vancomycin Dependence in VanA-Type Staphylococcus aureus VRSA-9 -- Meziane-Cherif et al. 192 (20): 5465 -- The Journal of Bacteriology.

The vancomycin-resistant Staphylococcus aureus VRSA-9 clinical isolate was partially dependent on glycopeptide for growth. The responsible vanA operon had the same organization as that of Tn1546 and was located on a plasmid. The chromosomal D-Ala:D-Ala ligase (ddl) gene had two point mutations that led to Q260K and A283E substitutions, resulting in a 200-fold decrease in enzymatic activity compared to that of the wild-type strain VRSA-6. To gain insight into the mechanism of enzyme impairment, we determined the crystal structure of VRSA-9 Ddl and showed that the A283E mutation induces new ion pair/hydrogen bond interactions, leading to an asymmetric rearrangement of side chains in the dimer interface. The Q260K substitution is located in an exposed external loop and did not induce any significant conformational change. The VRSA-9 strain was susceptible to oxacillin due to synthesis of pentadepsipeptide precursors ending in D-alanyl-D-lactate which are not substrates for the β-lactam-resistant penicillin binding protein PBP2'. Comparison with the partially vancomycin-dependent VRSA-7, whose Ddl is 5-fold less efficient than that of VRSA-9, indicated that the levels of vancomycin dependence and susceptibility to β-lactams correlate with the degree of Ddl impairment. Ddl drug targeting could therefore be an effective strategy against vancomycin-resistant S. aureus.

Animal MRSA Strain ST398 - Unusual Resistance Patterns

Small plasmids carrying vga(A) or vga(C) genes mediate resistance to lincosamides, pleuromutilins and streptogramin A antibiotics in methicillin-resistant Staphylococcus aureus ST398 from swine — J Antimicrob Chemother.

Methicillin-resistant Staphylococcus aureus (MRSA) isolates of the sequence type ST398 have been identified recently from cases of exudative epidermitis in swine, but also as colonizers of apparently healthy swine in Portugal.1,2 A considerable number of these isolates displayed an unusual resistance phenotype, namely resistance to the lincosamide clindamycin, but susceptibility to the macrolide erythromycin.1,2 Since the genetic basis of this resistance phenotype is unknown, we selected five representative isolates to identify the respective resistance genes, to determine whether they are transferable and to investigate their genetic environment. Of the five MRSA ST398 isolates, three (E32, E33 and E49) were obtained from dust samples in three different holdings of breeding pigs during the European Community baseline study, one (E8) was from the nasal swab of an apparently healthy sow and the remaining one (E18) was from a skin lesion of a piglet suffering from exudative epidermitis. PCR screening for the presence of the lincosamide resistance gene lnu(A)3 yielded negative results in repeated experiments using plasmid DNA or chromosomal DNA as targets.

MRSA Drugs and Skin Infections

Complicated skin and soft tissue infection — J Antimicrob Chemother.

The epidemiology of community-acquired and healthcare-acquired strains is constantly shifting and this presents challenges in the choice of empirical antibiotic therapy. Toxin production, particularly with Panton–Valentine leucocidin, may complicate the presentation still further. Polymicrobial infection with Gram-positive and Gram-negative organisms and anaerobes may occur in infections approximating the rectum or genital tract and in diabetic foot infections and burns. Successful management of cSSTI involves prompt recognition, timely surgical debridement or drainage, resuscitation if required and appropriate antibiotic therapy. The mainstays of treatment are the penicillins, cephalosporins, clindamycin and co-trimoxazole. β-Lactam/β-lactamase inhibitor combinations are indicated for polymicrobial infection. A range of new agents for the treatment of methicillin-resistant S. aureus infections have compared favourably with the glycopeptides and some have distinct pharmacokinetic advantages. These include linezolid, daptomycin and tigecycline. The latter and fluoroquinolones with enhanced anti-Gram-positive activity such as moxifloxacin are better suited for polymicrobial infection.

MRSA Strain ST93 - Whole Genome Analysed

Complete Genome Sequence of Staphylococcus aureus Strain JKD6159, a Unique Australian Clone of ST93-IV Community Methicillin-Resistant Staphylococcus aureus -- Chua et al. 192 (20): 5556 -- The Journal of Bacteriology.

Community methicillin-resistant Staphylococcus aureus (cMRSA) is an emerging issue that has resulted in multiple worldwide epidemics. We report the first complete genome sequence of an ST93-MRSA-IV clinical isolate that caused severe invasive infection and a familial outbreak of skin infection. This isolate is a representative of the most common Australian clone of cMRSA that is more distantly related to the previously sequenced genomes of S. aureus.

UK MRSA in Children - Usually the very young

Enhanced surveillance of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in children in the UK and Ireland -- Johnson et al. 95 (10): 781 -- Archives of Disease in Childhood.

Methods Cases were ascertained by active surveillance involving paediatricians reporting to the British Paediatric Surveillance Unit and by routine laboratory surveillance. Patient characteristics were obtained using questionnaires sent to reporting paediatricians. MRSA isolates were characterised using molecular and phenotypic techniques including antimicrobial susceptibility testing. Results 265 episodes of MRSA bacteraemia were ascertained, involving 252 children. The overall incidence rate was 1.1 per 100 000 child population per year (95% CI 0.9 to 1.2): 61% of the children were aged <1 year (a rate of 9.7 cases per 100 000 population per year (95% CI 8.2 to 11.4)) and 35% were <1 month. Clinical data were obtained from 115 cases. The clinical presentation varied, with fever present in only 16% of neonates compared with 72% of older children. A history of invasive procedure was common, with 32% having had intravascular lines and 13% having undergone surgery. 62% of patients for whom data were available were receiving high-dependency care (46% in SCBU/NICU and 16% in PICU). Of 93 MRSA isolates studied, 73% belonged to epidemic strains widely associated with nosocomial infection in the UK and Ireland. Conclusions MRSA bacteraemia in children was relatively uncommon and was predominantly seen in very young children, often those receiving neonatal or paediatric intensive care. Bacteraemia predominantly involved well-documented epidemic strains of MRSA associated with nosocomial infection.

3M Infection Prevention to Offer Series of Educational Events During MRSA Week

ADDING ADDITIONAL FACT SHEETS 3M Infection Prevention to Offer Series of Educational Events for Healthcare Professionals During Week of September 27 - MarketWatch.

"3M is focused on helping hospitals reduce HAIs and our commitment to serving patients and the institutions that care for them is unparalleled," said Debra Rectenwald, president and general manager of 3M's Infection Prevention Division. "Over the last year, we have made a number of strategic investments that provide hospitals with total solutions to their infection prevention needs. We are arming them with the latest information, resources and support to continue their efforts to make hospitals even safer for patients."

Activists to Unite to Call Attention to Fight Against MRSA

Activists to Unite to Call Attention to Fight Against Superbug that Sickens, Kills Thousands.

A number of MRSA survivors and their families and friends will be on hand to share their experiences with MRSA at the second annual World MRSA Day kickoff event at Loyola University Chicago. The event, held in conjunction with World MRSA Awareness Month in October, will take place from 10 a.m. to 12:30 p.m., Friday, Oct. 1, in the Simpson Room at Loyola University Chicago’s Lake Shore Campus, 1032 West Sheridan Road, Chicago. “We have a fantastic event planned this year with organizations, students, health officials, infectious disease specialists, legislators and MRSA infection survivors and family members along with the community coming together from across the country to raise awareness for MRSA,” said Jeanine Thomas, a MRSA infection survivor and founder of World MRSA Day and MRSA Survivors Network.

Oritavancin - a new MRSA drug candidate

Oritavancin Disrupts Membrane Integrity of Staphylococcus aureus and Vancomycin Resistant Enterococci to Effect Rapid Bacterial Killing -- Belley et al., 10.1128/AAC.00760-10 -- Antimicrobial Agents and Chemotherapy.

Oritavancin is an investigational lipoglycopeptide in clinical development for the treatment of acute bacterial skin and skin structure infections. In this study, we demonstrate that oritavancin causes bacterial membrane depolarization and permeabilization leading to cell death of gram-positive pathogens and that these effects are attributable to the 4'-chlorobiphenylmethyl group of the molecule.

MRSA in Newborns - The Statistics

Neonatal infections in England: the NeonIN surveillance network -- Vergnano et al. -- ADC - Fetal and Neonatal Edition.

Results With the inclusion of coagulase negative Staphylococci (CoNS), the incidence of all neonatal infection was 8/1000 live births and 71/1000 neonatal admissions (2007–2008). The majority of infections occurred in premature (<37 weeks) and low birthweight (<2500 g) infants (82% and 81%, respectively). The incidence of early onset sepsis (EOS; ≤48 h of age) was 0.9/1000 live births and 9/1000 neonatal admissions, and group B Streptococcus (58%) and Escherichia coli (18%) were the most common organisms. The incidence of late onset sepsis (LOS; >48 h of age) was 3/1000 live births and 29/1000 neonatal admissions (7/1000 live births and 61/1000 admissions including CoNS) and the most common organisms were CoNS (54%), Enterobacteriaceae (21%) and Staphylococcus aureus (18%, 11% of which were methicillin resistant S aureus). Fungi accounted for 9% of LOS (72% Candida albicans). The majority of pathogens causing EOS (95%) and LOS (84%) were susceptible to commonly used empiric first line antibiotic combinations of penicillin/gentamicin and flucloxacillin/gentamicin, respectively (excluding CoNS).

Successful treatment of vancomycin resistance with Telavancin

Successful treatment of vancomycin-intermediate Staphylococcus aureus pacemaker lead infective Endocarditis with Telavancin -- Marcos and Camins, 10.1128/AAC.00857-10 -- Antimicrobial Agents and Chemotherapy.

Emerging infections caused by the vancomycin-intermediate Staphylococcus aureus (VISA) isolates are more likely to be associated with treatment failures. We present a case of pacemaker lead infective endocarditis caused by a daptomycin non-susceptible strain of VISA. After eight weeks of parenteral telavancin therapy, the patient achieved microbiological and clinical cure.

Novel Gene Aids Resistance in MRSA ST398

Novel Apramycin Resistance Gene apmA in Bovine and Porcine Methicillin-resistant Staphylococcus aureus ST398 -- Feßler et al., 10.1128/AAC.01124-10 -- Antimicrobial Agents and Chemotherapy.

A novel apramycin resistance gene, apmA, was detected on the ca. 40-kb resistance plasmid pAFS11 from bovine MRSA ST398. The apmA gene coded for a protein of 274 amino acids which was only distantly related to acetyltransferases involved in chloramphenicol or streptogramin A resistance. NsiI deletion of apmA resulted in a 16- to 32-fold decrease in the apramycin MICs. An apmA-specific PCR identified this gene in one additional bovine and four porcine MRSA ST398 isolates.

Meat tainted with deadly MRSA bacteria is being sold to consumers

Meat tainted with deadly virus is being sold to consumers; government forms 'work group'.

A number of clinical and academic studies bear this out: a recent Canadian study showed nearly 14% of pork chops (about one in seven) and 6.3% of ground pork sold in supermarkets carried the contamination -- taken together, 9.6% of all pork samples. Additionally, 5.6% of the beef and 1.2% of the poultry carried the bug. The bacterium was also found in veal, lamb and other meats. Another report, by Louisiana State University, found 5.5% of pork samples and 3.3% of beef samples taken from local supermarkets were contaminated. Yet another - this one out of the pork industry's lobby arm, the National Pork Board -- found MRSA in 3% of pork samples.  While some controversy exists about the particular strains of the infection and the likelihood that not all MRSA-contaminated meat is linked to the way the animals were raised, the U.S. Department of Agriculture, which oversees the meat industry, does not mandate or carry out any rigorous testing for MRSA in meat, nor does it issue recalls. "I don't think the USDA wants to touch this. They know if they start testing for MRSA, they're going to find infected pork and that will force them to make a decision, one that would hugely impact the meat export industry," said Kirby, who has hit a brick wall when trying to get answers from the agency.

MRSA Research and eradicating the 'Sleeper' cells

Surviving antibiotics... - The Gene Gym Blog | Nature Publishing Group.

Whilst the idea of targeting non-growing bacteria is not a wholly new idea (you can find a review on the subject by Prof. Coates in my 'Further reading'), it does seem that together with the report's first author, Dr Yanmin Hu, their spin-out company (Helperby Therapeutics) has developed a platform and proof of principle drug that is now in trials, demonstrating the utility of such an approach. They have identified an antibiotic compound that has potent anti-Staphylococcal activity, but importantly, acts specifically against non-multiplying cells. In a second paper, brought to my attention by Ed Yong, the Collins lab in Boston has identified that a sub-population of super-resistant bacteria act in a charitable manner to other members of the colony that are less resistant. Whilst the super-resistant cells could satisfy their own selfishness by merely allowing all their less-resistant siblings to die out, the bacteria in this case have a mutation that maintains their production of indole (a signalling molecule) when normally its production would be shut down on exposure to the antibiotic. When released by the cell, indole stimulates non-resistant cells to enter a state of phenotypic resistance or 'antibiotic survival', even though continued-production of indole incurs a fitness cost.

Patient Screening: Everyone or High Risk Only?

HighWire Medline Abstract.

The UK Government has prioritised methicillin-resistant Staphylococcus aureus (MRSA) screening and new operational guidance has instructed that all day-case surgical patients should be screened from April 2009. RESULTS Six patients (2.1%;) screened MRSA-positive (DH estimate 7%;); five were previously known to be MRSA-positive, therefore only 0.36%; patients were newly-identified as MRSA-positive. The proportion of patients screened increased from 35%; to 72.5%; after April 2009, in accordance with DH guidance. Successful decolonisation was proved in two patients (33.3%;).CONCLUSIONS  It is not cost-effective to screen all vascular day-case admissions. We recommend selective screening for patients previously identified as MRSA-positive, or considered high risk.

Farmer health conference tackles MRSA antibiotic resistance

Farmer health conference tackles antibiotic resistance - State News - Agribusiness and General - General - Farm Weekly.

ANTIBIOTIC-resistant bacteria in the animals we eat will be on the menu at the inaugural National Centre for Farmer Health Conference in Hamilton, Victoria, next month. American Professor Kelley J. Donham will give a current risk assessment for methicillin-resistant Staphylococcus aureus or MRSA and management tips during the conference in the Hamilton Performing Arts Centre from October 11-13. National Centre for Farmer Health director clinical associate professor Sue Brumby said MRSA was well-recognised as a hospital-acquired infection but had recently been detected in livestock, including in cattle and poultry, in Europe and Asia. Professor Brumby said the conference would also cover Q Fever, equine influenza, leptospirosis, cross staph infections and needle stick injuries.

415V Steam Cleaner Thwarts MRSA Microbes

415V Steam Cleaner Thwarts MRSA Microbes.

MRSA microbes are particularly dangerous because of their immunity to standard antibiotic regimens. Generally, these germs have been confined to hospital settings. But scientists have recently detected the microorganisms in settings frequented by the general population. “These new lab tests confirm the disinfecting abilities of the ATIS® design found in the 8441-360CVP,” In the tests sited earlier, the ATIS® technology found in the KleenJet® 8441-360 CVP steam cleaner eradicated 99.99 % of MRSA in laboratory experiments. Previously, ATIS® proved its efficacy on a host of other unhealthy microbes, including listeria and salmonella. The 8441-360CVP is equipped for 415 volt, 3 phase, 60 Hz power. The 4,850 watt unit outputs nearly three times as much as steam as a 1600-watt machine. The added power results in longer periods of high-density steam. The vacuum steam cleaner is manufactured with a 14-liter boiler subsystem that includes: stainless steel construction, a lifetime warranty and a removable heating element for quick repairs by a technician. The ATIS® sanitizing system resides in the boiler. The machine features both wet and dry vacuuming. The wet feature improves productivity and decrease time spent hand wiping. The dry vacuum feature extracts pollen, spores, and allergy-aggravating substances.

More MRSA bacteria on lift buttons than toilet seats

More bacteria on lift buttons than toilet seats.

The number of bacteria on a lift button can be significantly higher than on a public toilet seat, the results of a new study indicate. US researchers collected bacteria samples from hotels, restaurants, banks, offices and airports. They found that the level of bacteria on lift buttons averaged 2,200 colony forming units per square centimeter. On the average public toilet seat, this figure was just eight. Among the common bacteria found were E.coli and MRSA. The research was carried out on behalf of Mircoban Europe, which manufactures antibacterial protection products. According to Dr Nicholas Moon of Microban, in a busy building, a lift button can be touched by ‘dozens of different people who will have come into contact with all kinds of bacteria every hour'.

Seagulls spreading vancomycin resistant superbugs?

Seagulls spreading superbugs? - Health Insurance News.

A healthcare plan to treat superbugs may be needed after it was found that deadly bacteria could be being spread by migratory birds. Portuguese researchers have found that antibiotic-resistant bacteria can be carried by seagulls. They studied 57 samples of droppings from the yellow-legged Caspian Gull Larus Cachinnans, finding that one in ten contained bacteria resistant to the antibiotic vancomycin, which is a last resort treatment used when most other antibiotics have failed. Reported in the journal Proteome Science, the scientists speculate the birds pick up the infections from eating scraps in human garbage. "Migrating birds that fly and travel long distances can act as transporters, or as reservoirs, of antibiotic-resistant bacteria and may consequently have a significant epidemiological role in the dissemination of resistance," said lead scientist Gilberto Igrejas, of the University of Tras-os-Montes and Alto Douro. The white and grey seagulls used in the study are common in many southern parts of the UK. It was recently reported that the Health Protection Agency has found evidence that superbug versions of common food poisoning, such as e.coli, are present in farm animals across Britain.