The need for continued monitoring of antibiotic resistance patterns in clinical isolates of Staphylococcus aureus from London and Malta

Antibiotic resistance is an increasing problem in isolates of Staphylococcus aureus (S. aureus) worldwide. In 2001 The National Health Service in the UK introduced a mandatory bacteraemia surveillance scheme for the reporting of S. aureus and methicillin-resistant S. aureus (MRSA). This surveillance initiative reports on the percentage of isolates that are methicillin resistant. However, resistance to other antibiotics is not currently reported and therefore the scale of emerging resistance is currently unclear in the UK. In this study, multiple antibiotic resistance (MAR) profiles against fourteen antimicrobial drugs were investigated for 705 isolates of S. aureus collected from two European study sites in the UK (London) and Malta.

Epidemiology of community-acquired meticillin-resistant Staphylococcus aureus obtained from the UK West Midlands region

Between January 2005 and December 2005, 199 meticillin-resistant Staphylococcus aureus (MRSA) isolates were obtained from nonhospitalised patients presenting skin and soft tissue infections to local general practitioners. The study area incorporated 57 surgeries from three Primary Care Trusts in the Lichfield, Tamworth, Burntwood, North and East Birmingham regions of Central England, UK. Following antibiotic susceptibility testing, pulsed-field gel electrophoresis, Panton-Valentine leukocidin gene detection and SCCmec element assignment, 95% of the isolates were shown to be related to hospital epidemic strains EMRSA-15 and EMRSA-16. In total 87% of the isolate population harboured SCCmec IV, 9% had SCCmec II and 4% were identified as carrying novel SCCmec IIIa-mecI. When mapped to patient home postcode, a diverse distribution of isolates harbouring SCCmec II and SCCmec IV was observed; however, the majority of isolates harbouring SCCmec IIIa-mecI were from patients residing in the north-west of the study region, highlighting a possible localised clonal group. Transmission of MRSA from the hospital setting into the surrounding community population, as demonstrated by this study, warrants the need for targeted patient screening and decolonisation in both the clinical and community environments.

Anti-bacterial skin disinfectants in the reduction of methicillin resistant staphylococcus aureus (MRSA) skin colonisation

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Evaluation of molecular typing methods for methicillin resistant staphylococcus aureus

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Rapid serodiagnosis of Staphylococcus aureus surgical site infection following median sternotomy

Objectives: To determine the sensitivity and specificity of a novel ELISA for the serodiagnosis of surgical site infection (SSI) due to staphylococci following median sternotomy. Methods: Twelve patients with a superficial sternal SSI and 19 with a deep sternal SSI due to Staphylococcus aureus were compared with 37 control patients who also underwent median sternotomy for cardiac surgery but exhibited no microbiological or clinical symptoms of infection. A further five patients with sternal SSI due to coagulase-negative (CoNS) staphylococci were studied. An ELISA incorporating a recently recognised exocellular short chain form of lipoteichoic acid (lipid S) recovered from CoNS, was used to determine serum levels of anti-lipid S IgG in all patient groups. Results: Serum anti-lipid S IgG titres of patients with sternal SSI due to S. aureus were significantly higher than the control patients (P<0.0001). In addition, patients with deep sternal SSI had significantly higher serum anti-lipid S IgG titres than patients with superficial sternal SSI (P=0.03). Serum anti-lipid S IgG titres of patients with sternal SSI due to CoNS were significantly higher than the control patients (P=0.001). Conclusion: The lipid S ELISA may facilitate the diagnosis of sternal SSI due to S. aureus and could also be of value with infection due to CoNS. © 2005 Published by Elsevier Ltd. on behalf of The Bristish Infection Society.

Methicillin-resistant Staphylococcus aureus bacteremia:epidemiology, outcome, and laboratory characteristics in a tertiary referral center in the UK

Objective: To analyze the recent epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia in a UK tertiary referral center. Methods: We collected epidemiological and laboratory data on all cases of MRSA bacteremia from September 1, 2005 to December 31, 2007. Results: There were 195 clinically significant episodes. Most were hospital-acquired. Only one episode occurred in patients without a history of hospital admission in the previous 12 months. An intravascular device was the most common focus of infection (37%), with no identifiable source found in 35% of episodes. Twenty-eight percent of patients died within 30 days of bacteremia. Mortality was significantly higher in the absence of an identifiable focus. Failure to include an antibiotic active against MRSA in the empirical treatment was only significantly associated with death in patients showing signs of hemodynamic instability (p < 0.001). No isolates had a minimum inhibitory concentration to vancomycin above 1.5. mg/l and no heteroresistance to glycopeptide antibiotics (heteroresistant vancomycin-intermediate Staphylococcus aureus; hVISA) was detected. All isolates were sensitive to daptomycin, tigecycline, and linezolid. Conclusions: Despite improvement in infection control measures, medical devices remain the most common source of infection. Inappropriate empirical antibiotic usage is associated with a poor outcome in patients with signs of severe sepsis. Susceptibility to glycopeptides and newer antibiotics remains good. © 2010 International Society for Infectious Diseases.

An ethnopharmacological approach to multidrug -resistant Staphylococcus aureus: Evaluation of Italian plants used in the traditional healing of skin disease

One-third of botanical remedies from southern Italy are used to treat skin and soft tissue infections (SST's). Methicillin-resistant Staphylococcus aureus (MRSA), a common cause of SSTIs, is responsible for increased morbidity and mortality from infections. Therapeutic options are limited by antibiotic resistance. Many plants possess potent antimicrobial compounds for these disorders. Validation of traditional medical practices is important for the people who rely on medicinal plants. Moreover, identification of novel antibiotics and anti-pathogenic agents for MRSA is important to global healthcare.^ I took an ethnopharmacological approach to understand how Italian medicinal plants used for the treatment of SSTIs affect MRSA growth and virulence. My hypothesis was that plants used in folk remedies for SSTI would exhibit lower cytotoxicity and greater inhibition of bacterial growth, biofilm formation and toxin production in MRSA than plants used for remedies unrelated to the skin or for plants with no ethnomedical application. The field portion of my research was conducted in the Vulture-Alto Bradano area of southern Italy. I collected 104 plant species and created 168 crude extracts. In the lab, I screened samples for activity against MRSA in a battery of bioassays. Growth inhibition was analyzed using broth microtiter assays for determination of the minimum inhibitory concentration. Interference with quorum-sensing (QS) processes, which mediate pathogenicity, was quantified through RP-HPLC of δ-toxin production. Interference with biofilm formation and adherence was assessed using staining methods. The mammalian cytotoxicity of natural products was analyzed using MTT cell proliferation assay techniques.^ Although bacteriostatic activity was limited, extracts from six plants used in Italian folk medicine (Arundo donax, Ballota nigra, Juglans regia, Leopoldia comosa, Marrubium vulgare, and Rubus ulmifolius ) significantly inhibited biofilm formation and adherence. Moreover, plants used to treat SSTI demonstrated significantly greater anti-biofilm activity when compared to plants with no ethnomedical application. QSI activity was evident in 90% of the extracts tested and extracts from four plants ( Ballota nigra, Castanea saliva, Rosmarinus officinalis, and Sambucus ebulus) exhibited a significant dose-dependent response. Some of the plant remedies for SSTI identified in this study can be validated due to anti-MRSA activity.^

Antibacterial activity of the marine sponge Ircinia Campana collected at Punta Uva Limón against Staphylococcus Aureus

The sponges are simple multicellularorganisms; they inhabit in marine environments from the polar seas to the tropical waterswhere they are more abundant. These species are exposed to large populations of microbes, reason that explains their complex morphological and cellular defense mechanism, which are used by these organisms to fight against pathogens. The purpose of this study was to evaluate the antibacterial activity of the marine sponge Ircinia campana, whichinhabits in the south of the Caribbean coast of Costa Rica against  Sthapylococcus aureus gram-positive bacteria. Sampleswere collected in Punta Uva in Limónduring July of 2007. The active compounds were obtainedby extraction with acetone (crude extract); and subsequently, chromatographic extracts were obtained using fractions 1:4 hexane: ethyl acetate. The antibacterial activities of the different fractions, including the  crude extract were tested.Our results suggest a zone of inhibition of 14.60 ±0.25 mm for the crude extract and18.70±0.25mm for the most active fraction separated by chromatography. The metabolite responsible for the antibacterial activity was isolated by High Performance Liquid Chromatography (HPLC)and preliminarily characterized through ultraviolet (UV) and infrared (IR) spectroscopy.

Resistencia antimicrobiana de Staphylococcus aureus en pacientes con pie diabético que asisten a la consulta externa del Hospital Nacional Dr. Jorge Arturo Mena de Santiago de María, departamento de Usulután en el período de junio a agosto de 2014

La resistencia bacteriana es uno de los problemas de Salud Pública más graves, los microorganismos que causan enfermedades infecciosas han dejado de responder a los antibióticos de uso común; en la investigación el objetivo fue determinar la resistencia antimicrobiana de Staphylococcus aureus en pacientes con pie diabético que asistieron a la Consulta Externa del Hospital Nacional Dr. Jorge Arturo Mena de Santiago de María, departamento de Usulután en el período de junio a agosto de 2014; a los antibióticos Eritromicina, Clindamicina, Ampicilina, Ciprofloxacina, Ceftriaxona, Cotrimoxazol; utilizados en el tratamiento de infecciones por bacterias grampositivas, para lo cual se observaron y analizaron 30 muestras de personas con pie diabético para obtener una población de 10 personas a quienes se les aisló la bacteria Staphylococcus aureus y se les realizó el respectivo antibiograma. Metodología fue un estudio de tipo prospectivo, transversal, descriptivo y de campo; los datos obtenidos fueron ordenados y tabulados en donde se obtuvieron las siguientes Resultados se determinó que existe resistencia antimicrobiana de Staphylococcus aureus a los antibióticos: Eritromicina 70%, Clindamicina 60%, Ampicilina 60%, Ciprofloxacina 50%, Ceftriaxona 40% y Crotrimoxazol 20%; en pacientes con pie diabético que asistieron a la Consulta Externa del Hospital Nacional Dr. Jorge Arturo Mena de Santiago de María; mediante la utilizando la técnica de Kirby-Bauer y se cumplió con la norma del CLSI (Clinical and Laboratory Standards Institute). La población en estudio manifestó no conocer que el no tomar el tratamiento completo puede producir resistencia bacteriana 60%, el 90% recibió tratamiento con el antibiótico Ciprofloxacina, 70% Eritromicina, 50% Clindamicina y Ampicilina; el 60% no recordaba cuantas veces había recibido tratamiento con los antibióticos mencionados, factores que contribuyen a las complicaciones de quienes padecen pie diabético y son tratados por infecciones bacterianas.También se obtuvo resistencia antimicrobiana de otras bacterias aisladas en el estudio, donde: Enterococcus sp presentó una resistencia en un 100% a los antibióticos Cotrimoxazol, Ceftriaxona y Ciprofloxacina, al igual que Pseudomonas sp que es una bacteria nosocomial, manifestó ser resistente en un 50% a los 3 antibióticos; Escherichia coli presentó un 41.7% de resistencia al antibiótico Cotrimoxazol, Ciprofloxacina 33.3% y Ceftriaxona 25%; a diferencia de Proteus sp y Staphylococcus coagulasa negativa que no presentaron resistencia. Conclusiones: Staphylococcus aureus presento mayor resistencia al antibiótico Eritromicina 70%; uno de los factores que influye puede ser que la población en estudio manifestó en un 60% no saber que el abandonar los tratamientos producen resistencias bacteriana.

Prevalencia de infección por Staphylococcus aureus resistente a meticilina en heridas crónicas en atención primaria de Lleida: estudio retrospectivo

Objetivo: averiguar la prevalencia de infecciones por Staphylococcus aureus (S. aureus) y S. aureus resistente a meticilina (MRSA) en los cultivos de heridas crónicas en atención primaria de la región sanitaria de Lleida y valorar la prescripción de antibioterapia oral según resultado del antibiograma. Diseño: estudio transversal retrospectivo. Muestra: cultivos realizados en heridas crónicas de enero de 2010 a diciembre 2012. Resultados: se estimó una prevalencia de cultivos positivos a Staphylococcus aureus resistente a meticilina de 3,77% (intervalo de confianza IC al 95%: 2,1-5,5) y de S. aureus no resistente a meticilina de 8,79% (IC 95%: 1,1-6,1) calculado sobre el número total de cultivos registrados en este periodo. Conclusiones: la prescripción de antibióticos respecto al antibiograma es más precisa al tener como respuesta un MRSA que un cultivo de S. aureus.