Biofilm phenotypes were studied in 32 Staphylococcus aureus strains isolated from store-bought meats and 22 from diseased patients in hospitals. Of the meat-associated strains, 21 were methicillin-resistant Staphylococcus aureus (MRSA) and 11 were methicillin-susceptible Staphylococcus aureus (MSSA). The hospital-associated strains included 15 MRSAs and 7 MSSAs. We studied the robustness and composition of the biofilms produced by these strains. We found that on average hospital-associated strains form more robust biofilms than meat associated strains. The model often used to describe S. aureus biofilm composition includes two biofilm types defined by the presence or absence of polysaccharide intercellular adhesin (PIA), PIA-dependent and PIA-independent respectively. In this model, PIA-independent biofilms are structurally reliant on proteins and extracellular DNA (eDNA) and PIA-dependent are structurally reliant on polysaccharides. Enzymatic degradation of the extracellular matrix can reveal which compounds are essential for the structural integrity of the biofilm, and by this model PIA-independent biofilms should be susceptible to both DNase and proteinase K. We found that hospital-associated strains are, on average, more susceptible to degradation by proteinase K. Interestingly, hospital-associated strains are less susceptible to degradation by DNase than meat-associated strains. Finding that proteinase K and DNase susceptibility for these strains are not linked gives evidence to support the idea that S. aureus biofilm composition can vary greatly from strain to strain and that the PIA-dependent and PIA-independent dichotomy of the standard model may be insufficient to describe the variety of S. aureus biofilm composition and may only apply to the extremes of the spectrum. Additionally, we saw no relationship between MRSA or MSSA strains and biofilm robustness, proteinase K degradation, or DNase degradation. Differences in biofilm characteristics between hospital-associated and meat-associated strains reinforce previous findings that these populations are genetically distinct.

No description available.

<p>The purpose of this study was to describe the level of knowledge that nurse students in term 6 have about Methicillin-Resistant Staphylococcus aureus (MRSA) and basic hygiene routines. The data collection was carried out by questionnaires. The questionnaire contained questions about knowledge regarding MRSA and basic hygiene routines. The questionnaires were handed out at an obligatory tuition occasion and all of the nurse students who were present (n=57) were asked to take part. The sample consisted of 45 women and 12 men. The youngest participant was 22 years old and the oldest participant was 52 years old. The main results showed a large variation regarding the participants knowledge on the subjects. Regarding questions about basic hygiene routines the majority had given the right answers. The number of right answers in the survey on questions about the participants knowledge of MRSA was lower. Only 12 % had given the right answer to the question about common symptoms of MRSA infection. Regarding the question about whether the nurse students considered themselves knowledgeable enough about MRSA for their future occupation, 32% had answered "to a high degree".</p> / <p>Syftet med studien var att beskriva vilka kunskaper sjuksköterskestuderande i termin 6 har om Methicillinresistenta Staphylococcus aureus (MRSA) och basala hygienrutiner. Datainsamlingen genomfördes med enkäter. Enkäten innehöll frågor om kunskaper gällande MRSA samt basala hygienrutiner. Enkäterna delades ut vid ett obligatoriskt undervisningstillfälle och samtliga, vid undervisningstillfället närvarade sjuksköterskestudenter (n =57) tillfrågades om deltagande. Undersökningsgruppen bestod av 45 kvinnor och 12 män. Yngsta deltagaren var 22 år och den äldsta deltagaren var 52 år. Huvudresultatet visade en stor variation gällande deltagarnas kunskaper i ämnena. På frågor angående basala hygienrutiner hade majoriteten svarat rätt. På de frågor som berörde deltagarnas kunskaper om MRSA var antalet rätta svar i undersökningen lägre. Endast 12 % hade svarat rätt på frågan om symtom som är vanliga vid MRSA infektion. På frågan om sjuksköterskestudenterna ansåg att de hade tillräckliga kunskaper om MRSA för sitt kommande yrke som sjuksköterskor svarade 32 % ”i hög grad”.</p>

The purpose of this study was to describe the level of knowledge that nurse students in term 6 have about Methicillin-Resistant Staphylococcus aureus (MRSA) and basic hygiene routines. The data collection was carried out by questionnaires. The questionnaire contained questions about knowledge regarding MRSA and basic hygiene routines. The questionnaires were handed out at an obligatory tuition occasion and all of the nurse students who were present (n=57) were asked to take part. The sample consisted of 45 women and 12 men. The youngest participant was 22 years old and the oldest participant was 52 years old. The main results showed a large variation regarding the participants knowledge on the subjects. Regarding questions about basic hygiene routines the majority had given the right answers. The number of right answers in the survey on questions about the participants knowledge of MRSA was lower. Only 12 % had given the right answer to the question about common symptoms of MRSA infection. Regarding the question about whether the nurse students considered themselves knowledgeable enough about MRSA for their future occupation, 32% had answered "to a high degree". / Syftet med studien var att beskriva vilka kunskaper sjuksköterskestuderande i termin 6 har om Methicillinresistenta Staphylococcus aureus (MRSA) och basala hygienrutiner. Datainsamlingen genomfördes med enkäter. Enkäten innehöll frågor om kunskaper gällande MRSA samt basala hygienrutiner. Enkäterna delades ut vid ett obligatoriskt undervisningstillfälle och samtliga, vid undervisningstillfället närvarade sjuksköterskestudenter (n =57) tillfrågades om deltagande. Undersökningsgruppen bestod av 45 kvinnor och 12 män. Yngsta deltagaren var 22 år och den äldsta deltagaren var 52 år. Huvudresultatet visade en stor variation gällande deltagarnas kunskaper i ämnena. På frågor angående basala hygienrutiner hade majoriteten svarat rätt. På de frågor som berörde deltagarnas kunskaper om MRSA var antalet rätta svar i undersökningen lägre. Endast 12 % hade svarat rätt på frågan om symtom som är vanliga vid MRSA infektion. På frågan om sjuksköterskestudenterna ansåg att de hade tillräckliga kunskaper om MRSA för sitt kommande yrke som sjuksköterskor svarade 32 % ”i hög grad”.

Syftet med föreliggande litteraturstudie var att beskriva upplevelsen av att vara bärare av meticillin-resistensta Stafylococcus aureus (MRSA) samt att kvalitetsbedöma de valda artiklarnas urval och bortfall. Artikelsökning i databaserna Cinahl, Medline och PsycInfo resulterade i inkludering av 12 artiklar. I resultatet framkom faktorerna: Upplevelsen av att vara smittbärare, MRSA:s påverkan på det dagliga livet, Stöd eller frånvaro av stöd från familj och vänner, Information och kunskap, Bemötande från vårdpersonal samt Upplevelsen av isolering. I resultatet framkom att personer bärare av MRSA upplevde rädsla att smitta andra, framförallt sina familjemedlemmar, och avstod från fysiskt kontakt. Personerna upplevde begränsningar i arbetslivet, i dagliga livet samt begränsningar av fysisk aktivitet. Stöd från familj och vänner hade stora betydelser för personernas anpassning till livet som bärare av MRSA. Flera personer med MRSA upplevde att de hade brister i kunskap och information om MRSA, vilket påverkade dem negativt. Positivt bemötande från vårdpersonal gjorde att personerna anpassade sig lättare till sin situation. Isoleringsvård upplevdes antingen som positiv eller som diskriminerande och en begränsning till deras självständighet. Urvalsprocessen beskrevs i tio artiklar och bortfall beskrevs i elva artiklar. Slutsatsen blev att personer med MRSA upplevde adekvat information om sitt tillstånd som en påverkande faktor vid livsstilsförändring. Brister som uppstod vid kunskapsförmedling, i relationer till vänner och familj samt i bemötandet från vårdpersonal upplevdes som negativa erfarenheter. / The aim of this study was to describe the experience of being a carrier of methicillin-resistant Staphylococcus aureus (MRSA) and to evaluate the quality of the selected articles sample and dropouts. Articles were search in databases Cinahl, Medline and PsycInfo which resulted in an inclusion of 12 articles. The result showed factors: The experience of being a carrier, MRSA's impact on daily life, Support or absence of support from family and friends, Information and knowledge, Encounter from health professionals and The experience of isolation. The result showed that individuals carrying MRSA experienced fear of infecting others, especially their family members, and refrained from physical contact. Participants experienced restrictions in the workplace, in everyday life, and limitation of physical activity. Support from family and friends had great meaning for persons adjusting to life as carriers of MRSA. Several people with MRSA felt that they were deficient in knowledge and information on MRSA, which affected them adversely. Positive attitude from health workers led to a facilitated adaption to the carriers’ situation. Isolation care was either percieved as a positive experience or caused discrimination in which subjects felt that their autonomy was restricted. The sample process was described in ten articles and dropouts were described in eleven articles. The conclusion of this study was that people with MRSA felt that adequate information about their condition as an influencing factor to lifestyle change. Deficiencies in sharing of knowledge, in relationships with friends and family as well as in the encounter with health professionals were perceived as negative experiences.

Coagulase positive staphylococci, Staphylococcus aureus and Staphylococcus pseudintermedius, are important causes of infection in human beings and dogs respectively. The rapid increase in the incidence of methicillin resistant S. aureus (MRSA) in people and its emergence in dogs has raised the profile of this organism in the veterinary community. Similarly, human S. pseudintermedius infections have also been recognized as the awareness of bidirectional human-dog transmission increases. Antimicrobial resistance has been complicating the treatment of S. aureus infections since the first penicillin resistance was observed in the 1940s. Methicillin resistance (resistance to the majority of â-lactams), is particularly troublesome as the â-lactams are a safe and effective class of antimicrobials for treating susceptible staphylococcal infections in both human beings and dogs. Additionally, resistance to other antimicrobial classes such as the macrolides, tetracyclines, sulfonamides and chloramphenicol, further complicates the treatment of staphylococcal infections. Particularly in small animal private practice, infections are often treated empirically, requiring knowledge of locally prevalent susceptibility patterns. The emergence of resistance to commonly used drugs necessitates surveillance to monitor the dissemination of resistance, and to guide antimicrobial therapy. In the last decade there have been many studies attempting to address gaps in our knowledge of the ecology of S. aureus and S. pseudintermedius in dogs. In particular, the prevalence of colonization with methicillin resistant staphylococci has been documented in different dog populations. However, failing to sample all relevant sites of colonization, may have decreased the sensitivity of these studies. The sites where coagulase positive staphylococci colonize dogs have not been systematically evaluated. The clinical and infection control implications of S. aureus infections, or colonization in the case of MRSA, requires timely laboratory identification. The tube coagulase test is arguably the most important tool used for identifying of staphylococcal species. Studies dating from the 1970s and 1980s suggested that the use of rabbit plasma, which is the current standard, may not be the ideal media for all situations and that different plasmas may need to be considered in different diagnostic situations. In this thesis, the ecology of coagulase positive staphylococci in dogs was studied from start to finish including sample collection, bacterial identification, antimicrobial susceptibility testing and molecular epidemiological investigations. This thesis will serve as a template to be used for follow up studies or by investigators setting up a surveillance program in their region. We found that multiple sites of colonization (nares, pharynx and rectum), are involved in both S. aureus and S. pseudintermedius carriage in dogs. Single site colonized dogs were identified, suggesting that maximal screening sensitivity requires sampling multiple body sites. When canine and rabbit plasma were compared, the time until clot formation was found to be significantly shorter with canine plasma. Although, the availability of canine plasma may limit its use in the diagnostic laboratory, investigators should be aware that rabbit plasma may not be ideal for all applications of the tube coagulase test. Antimicrobial susceptibility testing of canine S. aureus and S. pseudintermedius and human S. aureus isolates was done. Consistent with previous reports from Saskatoon, the S. pseudintermedius isolates were found to be overwhelmingly susceptible: pan-susceptibility was the most common phenotype identified. Antimicrobial resistance was more common among S. aureus than S. pseudintermedius including resistance to drugs which all S. pseudintermedius were susceptible to. No resistance to vancomycin, linezolid, daptomycin or quinupristin/dalfopristin was found. All isolates remained susceptible to at least one of tetracycline, clindamycin, chloramphenicol or trimethoprim/sulfamethoxazole which are often used for treating infections caused by multidrug resistant staphylococci. Finally, DNA fingerprinting revealed that the canine and human S. aureus isolates tested did not belong to mutually exclusive populations. Using AFLP, IS-typing and spa typing, many human and canine isolates were indistinguishable suggesting a common population, supporting the hypothesis that interspecies transmission occurs. The complex and under-characterized ecology of S. aureus and S. pseudintermedius requires more study so that risk factors for infection can be defined and effective infection control measures implemented. Because multiple species are involved, collaboration between veterinarians and human health professionals is imperative, and will no doubt yield the most success in our efforts to understand these potential pathogens.

Coagulase positive staphylococci, Staphylococcus aureus and Staphylococcus pseudintermedius, are important causes of infection in human beings and dogs respectively. The rapid increase in the incidence of methicillin resistant S. aureus (MRSA) in people and its emergence in dogs has raised the profile of this organism in the veterinary community. Similarly, human S. pseudintermedius infections have also been recognized as the awareness of bidirectional human-dog transmission increases. Antimicrobial resistance has been complicating the treatment of S. aureus infections since the first penicillin resistance was observed in the 1940s. Methicillin resistance (resistance to the majority of â-lactams), is particularly troublesome as the â-lactams are a safe and effective class of antimicrobials for treating susceptible staphylococcal infections in both human beings and dogs. Additionally, resistance to other antimicrobial classes such as the macrolides, tetracyclines, sulfonamides and chloramphenicol, further complicates the treatment of staphylococcal infections. Particularly in small animal private practice, infections are often treated empirically, requiring knowledge of locally prevalent susceptibility patterns. The emergence of resistance to commonly used drugs necessitates surveillance to monitor the dissemination of resistance, and to guide antimicrobial therapy. In the last decade there have been many studies attempting to address gaps in our knowledge of the ecology of S. aureus and S. pseudintermedius in dogs. In particular, the prevalence of colonization with methicillin resistant staphylococci has been documented in different dog populations. However, failing to sample all relevant sites of colonization, may have decreased the sensitivity of these studies. The sites where coagulase positive staphylococci colonize dogs have not been systematically evaluated. The clinical and infection control implications of S. aureus infections, or colonization in the case of MRSA, requires timely laboratory identification. The tube coagulase test is arguably the most important tool used for identifying of staphylococcal species. Studies dating from the 1970s and 1980s suggested that the use of rabbit plasma, which is the current standard, may not be the ideal media for all situations and that different plasmas may need to be considered in different diagnostic situations. In this thesis, the ecology of coagulase positive staphylococci in dogs was studied from start to finish including sample collection, bacterial identification, antimicrobial susceptibility testing and molecular epidemiological investigations. This thesis will serve as a template to be used for follow up studies or by investigators setting up a surveillance program in their region. We found that multiple sites of colonization (nares, pharynx and rectum), are involved in both S. aureus and S. pseudintermedius carriage in dogs. Single site colonized dogs were identified, suggesting that maximal screening sensitivity requires sampling multiple body sites. When canine and rabbit plasma were compared, the time until clot formation was found to be significantly shorter with canine plasma. Although, the availability of canine plasma may limit its use in the diagnostic laboratory, investigators should be aware that rabbit plasma may not be ideal for all applications of the tube coagulase test. Antimicrobial susceptibility testing of canine S. aureus and S. pseudintermedius and human S. aureus isolates was done. Consistent with previous reports from Saskatoon, the S. pseudintermedius isolates were found to be overwhelmingly susceptible: pan-susceptibility was the most common phenotype identified. Antimicrobial resistance was more common among S. aureus than S. pseudintermedius including resistance to drugs which all S. pseudintermedius were susceptible to. No resistance to vancomycin, linezolid, daptomycin or quinupristin/dalfopristin was found. All isolates remained susceptible to at least one of tetracycline, clindamycin, chloramphenicol or trimethoprim/sulfamethoxazole which are often used for treating infections caused by multidrug resistant staphylococci. Finally, DNA fingerprinting revealed that the canine and human S. aureus isolates tested did not belong to mutually exclusive populations. Using AFLP, IS-typing and spa typing, many human and canine isolates were indistinguishable suggesting a common population, supporting the hypothesis that interspecies transmission occurs. The complex and under-characterized ecology of S. aureus and S. pseudintermedius requires more study so that risk factors for infection can be defined and effective infection control measures implemented. Because multiple species are involved, collaboration between veterinarians and human health professionals is imperative, and will no doubt yield the most success in our efforts to understand these potential pathogens.

Our investigation sought to identify the incidence of treatment failure and its associated costs in patients with methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTIs) treated in the primary care setting. Thirteen clinics participated in this multi-site, observational study. Clinicians consented patients and collected clinical information, pictures, and wound swabs; isolates were processed in the principal investigator's laboratory. Treatment failure was defined as the occurrence of one or more of the following within 90 days: (1) change in antibiotic therapy, (2) subsequent need for incision and drainage, (3) SSTI at new site, (4) SSTI at same site, (5) emergency department visit, or (6) hospitalization. Cost estimates were obtained from the Agency for Healthcare Research and Quality (AHRQ) and Centers for Medicare and Medicaid Service's National Average Drug Acquisition Costs (NADAC). Patients were considered to have “moderate or complicated” SSTIs if they had a lesion ≥ 5cm in diameter, diabetes mellitus, or both. Patients not exhibiting these characteristics were classified as having “mild or uncomplicated” infections. Ninety-eight patients were enrolled. Most patients were of Hispanic ethnicity and more than half of all patients had a body mass index (BMI) ≥ 30kg/m2. The most common treatment modality was incision and drainage (I&D) plus antibiotics (57%). Treatment failure occurred in 21% of all patients at a mean additional cost of $1,933.71. Patients with moderate or complicated SSTIs who received I&D experienced significantly more treatment failures compared mild or uncomplicated patients who received I&D (36% vs. 10%; p = 0.04). The additional cost of treatment failure in patients with moderate or complicated SSTIs was nearly twice that of patients with mild or uncomplicated SSTIs ($2,093.40 vs. $1,255.02; p = 1.0). Treatment failure occurred sooner, on average, in the moderate or complicated group compared to the mild or uncomplicated group (11.8 days vs. 38.8 days; p = 0.06). Among patients with MRSA SSTIs treated in the primary care setting, the rate of treatment failure is high (21%) and costs are considerable ($1,933.71). / text

Σκοπός της παρούσας ερευνητικής εργασίας ήταν η επιδημιολογική μελέτη των σταφυλοκοκκικών λοιμώξεων από πηκτάση–αρνητικούς σταφυλοκόκκους (CNS) σε ασθενείς της Μονάδας Εντατικής Θεραπείας των πρόωρων νεογνών του Πανεπιστημιακoύ Γενικού Νοσοκομείου Πατρών (ΠΓΝΠ) μεταξύ 2002-2004. Κατά τη διάρκεια της μελέτης, συλλέχθηκαν συνολικά 287 στελέχη CNS. Τα στελέχη ελέγχθηκαν για την παραγωγή της πρωτεΐνης PBP2α και την ύπαρξη του γονιδίου mecA για τον προσδιορισμό των ανθεκτικών στη methicillin στελεχών CNS. Από το σύνολο των 287 CNS, τα 132 (46%) χαρακτηρίσθηκαν ως MRCNS. Τα MRCNS αποτελούν σοβαρό πρόβλημα για τα νοσοκομεία, γιατί αυξάνουν τον χρόνο παραμονής των ασθενών στο νοσοκομείο, άρα και το κόστος νοσηλείας και θεραπείας. Έγινε μελέτη του φαινοτύπου αντοχής των στελεχών σε αντιβιοτικά, της κλωνικής τους διασποράς και της ικανότητάς παραγωγής βιομεμβράνης σε σύγκριση με την παρουσία των γονιδίων του οπερονίου ica. Για την επιδημιολογική μελέτη των λοιμώξεων που οφείλονται σε MRCNS, μέθοδος αναφοράς είναι η PFGE, κυρίως σε συνδυασμό και με υβριδισμό του χρωμοσωμικού DNA με ειδικούς ανιχνευτές. Όλα τα στελέχη MRCNS ήταν πολυανθεκτικά και η πλειονότητά τους παρήγαγε βιομεμβράνη (89%). Μεταξύ των 115 στελεχών S. epidermidis αναδείχθηκε ένας κυριάρχος κλώνος (z) (77 στελέχη) και ακολούθησε ο κλώνος (g). Τα δέκα από τα δεκαέξι στελέχη του είδους S. haemolyticus ανήκαν στον κλώνο (y). Το οπερόνιο ica συμβάλλει στην παραγωγή της εξωκυττάριας ουσίας polysaccharide-intercellular-adhesin (ΡΙΑ) που είναι το κύριο συστατικό του biofilm. Η έκφραση των γονιδίων του οπερονίου ica επάγεται από την παρουσία του ρυθμιστικού γονιδίου sarA, ενώ καταστέλλεται από το γονίδιο icaR. Τα περισσότερα στελέχη που ήταν biofilm-θετικά (80%) έφεραν όλα τα γονίδια του οπερονίου ica και το τρανσποζόνιο IS256, ενώ τα υπόλοιπα 23 είχαν ποικίλους συνδυασμούς των γονιδίων. Η παρουσία όλων των γονιδίων του οπερονίου ica ανιχνεύθηκε σε τρία από τα δεκαπέντε biofilm-αρνητικά στελέχη. Αναδείχθηκαν ένας κύριος και δύο δευτερεύοντες biofilm-θετικοί, πολυανθεκτικοί MRCNS κλώνοι, που αποίκισαν και προξένησαν λοιμώξεις στα πρόωρα νεογνά. Μέρος της παρούσας ερευνητικής εργασίας ήταν η διερεύνηση της επίδρασης του χρόνου επώασης στη γονιδιακή έκφραση σε δεκατέσσερα αντιπροσωπευτικά στελέχη. Αυτό έγινε μέσω της ποσοτικοποίησης με αλυσιδωτή αντίδραση πολυμεράσης πραγματικού χρόνου (RT-PCR) των γονιδίων icaA και icaD τα οποία κυρίως σχετίζονται με την παραγωγή biofilm, καθώς και δύο ρυθμιστικών γονιδίων icaR και sarA σε σύγκριση με ένα συντηρημένο γονίδιο αναφοράς (23S rDNA). Ο έλεγχος έγινε σε στελέχη S. epidermidis που ήταν ανθεκτικά στη methicillin, κατατάσσονταν σε διαφορετικούς κλώνους, εμφάνιζαν διαφορετικό φαινότυπο σύνθεσης βιομεμβράνης και έφεραν ποικίλους συνδυασμούς γονίδιων. Οι αντιδράσεις απόλυτης ποσοτικοποίησης έκφρασης των γονιδίων είχαν υψηλή απόδοση (1,86 και 1,84 για την επώαση στις τέσσερις ώρες και δύο ώρες, αντίστοιχα). Η μαθηματική ανάλυση δεν έδειξε ιδιαίτερα μεγάλες διαφορές μεταξύ των αποτελεσμάτων για τα τέσσερα γονίδια και τους δύο χρόνους επώασης. Αυτό που παρατηρήθηκε ήταν οτι η έκφραση ήταν υψηλότερη στα biofilm-θετικά στελέχη. Προκειμένου να μελετηθεί η επίδραση της βακτηριακής προσκόλλησης στις διάφορες επιφάνειες τροποποιημένου και μη τροποποιημένου γυαλιού, πραγματοποιήθηκαν δυναμικά πειράματα, κάτω από δύο διαφορετικές συνθήκες ροής, σε δύο χρόνους επώασης σε τέσσερα στελέχη S. epidermidis. Η βακτηριακή προσκόλληση, η παραγωγή biofilm και ο σχηματισμός βιομεμβράνης στις τροποποιημένες επιφάνειες ήταν αυξημένα σε σχέση με τις μη τροποποιημένες. Αυτό ήταν σε συμφωνία με τα αποτελέσματα της γονιδιακής έκφρασης των γονιδίων icaA και icaD, μετά από ανάλυση της έκφρασης των γονιδίων icaA και icaD με RT-PCR, που έδειξε αυξημένες τιμές στις τροποποιημένες επιφάνειες, κυρίως στην υψηλή ροή. Επομένως, ο συνδυασμός της δράσης της χημείας της επιφάνειας και της ροής, επηρεάζουν την προσκόλληση, τον φαινότυπο και το γονότυπο των βακτηριακών στελεχών, όπως και την προσαρμογή τους στις αλλαγές του περιβάλλοντος. Η μελέτη της γονιδιακής έκφρασης μπορεί να βοηθήσει στην κατανόηση των αλληλεπιδράσεων της βακτηριακής προσκόλλησης με το βιοϋλικό. / A total of 132 methicillin-resistant coagulase-negative staphylococci (MRCNS) isolated from preterm neonates were studied for antibiotic resistance patterns, clonal distribution and biofilm formation in relation to the presence of ica operon. All MR-CNS were multi-resistant while the majority (89%) produced biofilm. Among 115 Staphylococcus epidermidis, a major clone (z) was identified (77 strains), followed by clone g. Ten out of 16 S. haemolyticus belonged to a common clone (y). Most of the biofilm-positive strains (80%) possessed all tested genes, while the remaining 23 had a variety of gene combinations. Presence of the entire ica cluster was detected in three out of 15 biofilm-negative strains. One major and two minor biofilm-positive, multi-resistant MRCNS clones were disseminated, colonizing and infecting hospitalized preterm neonates. Fourteen representative MR- S. epidermidis strains were selected and investigated for the expression of icaA and icaD genes, and two regulatory genes, icaR (repressor) and sarA (inducer), towards a housekeeping gene (23SrDNA), by Real-Time PCR (RT-PCR). These strains belonged to various clones, had different combinations of ica genes and biofilm-forming phenotypes. The experiments were performed in two incubation times, after two and four hours. Νο differences were observed at the gene expression level at the two tested times. In general, biofilm-positive strains had higher expression rates for ica operon and sarA genes and lower for the repressor of ica cluster gene (icaR). In order to investigate the interaction of bacteria with the surfaces after attachment, dynamic experiments were performed under two flow conditions. Two different surfaces were used, a modified and a non-modified glass surface. Bacterial adhesion, as well as biofilm production and biofilm formation, was much higher on the modified surface than on the non-modified one for four S. epidermidis strains. This was in agreement with icaA and icaD gene expression that showed increased expression by RT-PCR, for the bacteria adhered at the modified substrate, especially under the high shear rate. Therefore, the combined effect of surface chemistry and shear significantly influence the adhesion of interacting bacterial cells. This indicates that analysis of gene expression not only can greatly refine our knowledge of bacterial-material interactions, but also yield novel biomarkers for potential use in biocompatibility assessment.

INTRODUCTION: National obesity rates are leading to higher rates of Type 2 Diabetes, increasing the number of people at risk of invasive infections with Methicillin Resistant Staphylococcus aureus (iMRSA) upon onset of ESRD and hemodialysis. However, an association between adiposity and risk of iMRSA has not been researched. AIM: The purpose of this study is to describe the epidemiological characteristics of an iMRSA cohort in the Atlanta metro area between 2005-2008; to examine BMI-related health outcomes within the cohort; and to compare proportions of BMI categories in this cohort to BRFSS data. METHODS: Surveillance data collected by the CDC EIP program on iMRSA in Atlanta, Georgia was used. BMI was calculated for each eligible case. Statistical analysis was carried out in SPSS. Univariate and multivariate binary logistic regression analysis was performed on select variables. A p-value of < 0.05 and a 95% confidence interval (CI) were used to determine significance. BRFSS BMI data for Georgia was compared to the study population. RESULTS: Overweight and obese cases were more likely to be diagnosed with diabetes by regression analysis. Cases with diabetes were at greater odds of having undergone dialysis within the previous year (univariate OR=2.3, p=0.000; multivariate OR=2.5, p=0.000). The proportion of iMRSA patients with diabetes is much greater (42.8%) than in the general population of the United States (7.8-10.7%). DISCUSSION: The results indicate that there may be a higher risk for iMRSA in overweight and obese individuals, particularly if other adiposity-related health problems are present.