Methicillin-resistant Staphylococus Aureus Research Articles

Occurrence of antimicrobial resistance uropathogenic <i>Staphylococcus aureus</i> isolates from pregnant women attending antenatal clinics within Ilorin

Background: Staphylococus aureus associated with urinary tract infection (UTI) has become a serious health problem especially with the emergence of methicillin resistant Staphylococus aureus (MRSA) due to the acquisition of mecA gene leading to increasing maternal and perinatal burden. This study aimed to evaluate the prevalence of antimicrobial resistance, β-lactamase production and methicillin resistance among uropathogenic S. aureus among pregnant women attending selected antenatal clinics in Ilorin.Methods: Forty-five (45) out of 79 presumptive uropathogenic S. aureus isolated over a period of 12 months from urine samples of pregnant women were identified using standard bacteriological methods. Antibiogram studies was performed using gentamicin (CN-10μg), ciprofloxacin (CIP-5μg), ofloxacin (OFX-5μg), tetracycline (TE-30μg), sulphamethaxozole-trimethoprim (SXT-25μg), ampicillin (AMP-10 μg), penicillin G (P-10 units), nitrofurantoin (F-30 μg) and cefoxitin (FOX-30 μg) for the detection of MRSA by disc diffusion method. Furthermore, detection of β - lactamase producing S. aureus (BL-PSA) was carried out using Iodometric paper strip method.Results: Of the 45 S. aureus isolates, 80% were BL-PSA, MRSA (87%), exhibiting high resistance to penicillin G (97.8%), ampicillin (95.5%), tetracycline (77.8%) and sulphamethaxozole trimethoprim (64.4%). In addition, 56% were multidrug-resistant (MDR) exhibiting 20 different phenotypes with CN-P-SXT-TE-AMP-FOX (15.6%) being the majority. Notwithstanding, S. aureus isolates showed high sensitivity to nitrofurantoin (93.3%) and ofloxacin (91.1%).Conclusion: This study established an increasing resistance of S. aureus to different classes of antibiotics which emphasize the need for constant surveillance to monitor antimicrobial resistance trends. Routine screening for BL-PSA and MRSA among uropathogenic S. aureus is also advocated in order to reduce the development and spread of MDR isolates.

Organization of antibiotic stewardship in Europe: the way to go.

SummaryIt is more than two decades ago that a European Union conference on “The Microbial Threat” hosted by the Danish Government in Copenhagen in September 1998 issued recommendations to encourage good practice in the use of antimicrobial agents and reduce inappropriate prescribing. Essential components of those recommendations were antimicrobial teams in hospitals and the use of feedback to prescribers as well as educational activities. Two decades later, important surveillance systems on both antimicrobial resistance as well as on antibiotic consumption are functioning at the European level and in most European countries; European Committee on Antimicrobial Susceptibility Testing (EUCAST) has thoroughly re-evaluated, standardized and harmonized antibiotic susceptibility testing and breakpoints; there have been educational activities in many countries; and stewardship teams are now included in many guidelines and policy papers and recommendations. Yet, antimicrobial resistance problems in Europe have shifted from methicillin-resistant Staphylococus aureus (MRSA) to vancomycin-resistent Enterococcus faecium (VRE) and to multidrug-resistant gramnegative bacteria, while antibiotic consumption volumes, trends and patterns across countries do not show major and highly significant improvements. The way to go further is to recognize that better prescribing comes at a cost and requires investment in expert personnel, practice guideline drafting, and implementation aids, and, secondly, the setting of clear goals and quantitative targets for prescribing quality.

Effectiveness of methanol extract hydroid aglaophenia cupressina lamoureoux as antimicrobial in resistant Methicilline Staphylococcus Aureus (MRSA), Shigella sp., Malassezia furfur, and Candida albicans

Currently there are many studies that utilize potential of marine resources, because there are many potential bioactive compounds to be developed, especially to overcome multi-drug resistant (MDR) against antibiotics. Hydroid Aglaophenia cupressina Lamoureoux is a marine invertebrate that is often found around spermonde waters containing bioactive compounds that can be developed as a basic ingredient in medicine. This study aims to determine the effectiveness of methanol extract from the Aglaophenia cupessina L. hydroid in inhibiting the growth of Shigella sp. Sd 1617 bacteria, Methicillin-Resistant Staphylococus aureus (MRSA) ATCC 25923 and Malassezia furfur fungi ATCC 14521, and Candida albicans ATCC 10231. In this study, the bioactivity test of methanol extract was carried out by swab method on NA and PDA medium. The concentration of methanol extract used is 5%, 10%, 20% and 40%. Data obtained from measurements of inhibition zone diameter during the incubation period of 24 hours to 48 hours in the Shigella sp. and Methicillin-Resistant Staphylococus aureus (MRSA). While for the Malassezia furfur and Candida albicans fungi incubated for 48 hours to 72 hours. Data obtained in descriptive analysis. The results showed that methanol extract from Aglaophenia cupressina L. hydroid has potential as an antimicrobial which is bactericidal at all test concentrations against the bacterium Shigella sp., Methicillin-Resistant Staphylococus aureus (MRSA) is bacteriostatic (5%, 10%, 40%), bactericidal at a concentration of 20%. Against the fungi Malassezia furfur showed fungistatic properties in all variations in extract concentration, and against Candida albicans was fungicidal at concentrations of 5% and 10%, while concentrations of 20% and 40% were fungistatic.

Ionic Liquid Meidated Synthesis of Cellulose and Chitosan Composite for Purification of Drinking Water

A simple method was developed to synthesize composites containing cellulose (CEL) chitosan (CS), keratin (KER) (from wool, hair and chicken feather) and metal nanoparticles including silver, gold and copper oxide nanoparticles (AgNPs, AuNPs and CuONPs). In this method, butylmethylimmidazolium chloride ([BMIm+Cl-]), a simple ionic liquid, was used as the sole solvent and metal salts such as silver chloride, HAuCl4 or Copper oxide was added to the [BMIm+Cl-] solution during the dissolution process. The metal salts in the composites were completely converted to metallic nanoparticles (Ag0NPs, Au0NPS or CuONPs) by reducing it with NaBH4. FTIR, XRD and SEM results confirm that CEL, CS and KER remain chemically intact and homogeneously distributed in the composites, and that the Ag0NPs, Au0NPs or CuONPs in the composites is homogeneously distributed throughout the composites. All composites were found to exhibit excellent adsorbent for pollutants (endocrine disruptors, heavy metal ions) and antibacterial activity against many bacteria and fungi including Escherichia coli, Staphylococus aureus, Pseudomonas aeruginosa, methicillin resistant Staphylococus aureus (MRSA), vancomycin resistant Enterococus faecalis (VRE) and Candida Albicans. The antibacterial activity of both composites increases with the content of the nanoparticles in the composites. All nanoparticles composites were found to be toxic to human fibroblasts at higher concentration (e.g., >0.72 mmol for Ag0NPs). As expected, by lowering concentration of the NPs, (e.g., Ag0NPs concentration to <0.48 mmol), all three nanoparticle composites can be made biocompatible while still retaining their pollutant adsorber and antimicrobial activity. These results together with our previous finding that [CEL+CS+KER] composites can be used for controlled delivery of drugs (e.g. Ciprofloxacin) clearly indicate that the silver, gold and copper oxide nanoparticle composites possess all required properties for successfully used as dressing to treat chronic ulcerous infected wounds and to purify drinking water.

In vitro bactericidal activity of diterpenoids isolated from Aframomum melegueta K. Schum against strains of Escherichia coli, Listeria monocytogenes and Staphylococcus aureus

Abstract Ethnopharmacological relevance The ethnobotanical use of Aframomum melegueta in the treatment of urinary tract and soft tissue infection suggested that the plant has antimicrobial activity. Materials and methods To substantiate the folkloric claims, an acetone, 50:50 acetone:methanol and 2:1 chloroform:methanol extracts were tested against Escherichia coli K12 ; acetone extract and the fractions of acetone extracts were tested against Listeria monocytogenes . Bioassay-guided fractionation was performed on the extract using L. monocytogenes as the test organism to isolate the bioactive compounds which were then tested against all the other organisms. Results Four known labdane diterpenes (G3 and G5) were isolated for the first time from the rhizomes of A. melegueta and purified. These were tested against E. coli , L. monocytogenes , methicillin resistant Staphylococus aureus (MRSA) and S. aureus to determine antibacterial activity. The result showed that two compounds G3 and G5 exhibited more potent antibacterial activity compared to the current clinically used antibiotics ampicillin, gentamicin and vancomycin and can be potential antibacterial lead compounds. The structure of the labdane diterpenes were elucidated using nuclear magnetic resonance (NMR) spectroscopy and Mass spectrometry. A possible mode of action of the isolated compound G3 and its potential cytotoxicity towards mammalian cells were also discussed. Conclusion The results confirmed the presence of antibacterial compounds in the rhizomes of A. melegueta with a favourable toxicity profile which could be further optimized as antibacterial lead compounds.

In vitro bactericidal activity of diterpenoids isolated from Aframomum melegueta K.Schum against strains of Escherichia coli, Listeria monocytogenes and Staphylococcus aureus

Ethnopharmacological relevanceThe ethnobotanical use of Aframomum melegueta in the treatment of urinary tract and soft tissue infection suggested that the plant has antimicrobial activity. Materials and methodsTo substantiate the folkloric claims, an acetone, 50:50 acetone:methanol and 2:1 chloroform:methanol extracts were tested against Escherichia coli K12; acetone extract and the fractions of acetone extracts were tested against Listeria monocytogenes. Bioassay-guided fractionation was performed on the extract using L. monocytogenes as the test organism to isolate the bioactive compounds which were then tested against all the other organisms. ResultsFour known labdane diterpenes (G3 and G5) were isolated for the first time from the rhizomes of A. melegueta and purified. These were tested against E. coli, L. monocytogenes, methicillin resistant Staphylococus aureus (MRSA) and S. aureus to determine antibacterial activity. The result showed that two compounds G3 and G5 exhibited more potent antibacterial activity compared to the current clinically used antibiotics ampicillin, gentamicin and vancomycin and can be potential antibacterial lead compounds. The structure of the labdane diterpenes were elucidated using nuclear magnetic resonance (NMR) spectroscopy and Mass spectrometry. A possible mode of action of the isolated compound G3 and its potential cytotoxicity towards mammalian cells were also discussed. ConclusionThe results confirmed the presence of antibacterial compounds in the rhizomes of A. melegueta with a favourable toxicity profile which could be further optimized as antibacterial lead compounds.

Beyond conventional antibiotics for the future treatment of methicillin-resistantStaphylococcus aureusinfections: two novel alternatives

The majority of antibiotics currently used to treat methicillin-resistant Staphylococus aureus (MRSA) infections target bacterial cell wall synthesis or protein synthesis. Only daptomycin has a novel mode of action. Reliance on limited targets for MRSA chemotherapy, has contributed to antimicrobial resistance. Two alternative approaches to the treatment of S.aureus infection, particularly those caused by MRSA, that have alternative mechanisms of action and that address the challenge of antimicrobial resistance are cationic host defence peptides and agents that target S.aureus virulence. Cationic host defence peptides have multiple mechanisms of action and are less likely than conventional agents to select resistant mutants. They are amenable to modifications that improve their stability, effectiveness and selectivity. Some cationic defence peptides such as bactenecin, mucroporin and imcroporin have potent in vitro bactericidal activity against MRSA. Antipathogenic agents also have potential to limit the pathogenesis of Saureus. These are generally small molecules that inhibit virulence targets in S.aureus without killing the bacterium and therefore have limited capacity to promote resistance development. Potential antipathogenic targets include the sortase enzyme system, the accessory gene regulator (agr) and the carotenoid biosynthetic pathway. Inhibitors of these targets have been identified and these may have potential for further development.

Synthesis and biological activity of 2-aminoimidazole triazoles accessed by Suzuki–Miyaura cross-coupling

A pilot library of 2-aminoimidazole triazoles (2-AITs) was synthesized and assayed against Acinetobacter baumannii and methicillin-resistant Staphylococus aureus (MRSA). Results from these studies show that these new derivatives have improved biofilm dispersal activities as well as antibacterial properties against A. baumannii. With MRSA biofilms they are found to possess biofilm inhibition capabilities at low micromolar concentrations.

Dissemination of Methicillin‐ResistantStaphylococcus aureusUSA300 Sequence Type 8 Lineage in Latin America

Methicillin-resistant Staphylococus aureus (MRSA) is an important nosocomial and community-associated (CA) pathogen. Recently, a variant of the MRSA USA300 clone emerged and disseminated in South America, causing important clinical problems. S. aureus isolates were prospectively collected (2006-2008) from 32 tertiary hospitals in Colombia, Ecuador, Peru, and Venezuela. MRSA isolates were subjected to antimicrobial susceptibility testing and pulsed-field gel electrophoresis and were categorized as health care-associated (HA)-like or CA-like clones on the basis of genotypic characteristics and detection of genes encoding Panton-Valentine leukocidin and staphylococcal cassette chromosome (SCC) mec IV. In addition, multilocus sequence typing of representative isolates of each major CA-MRSA pulsotype was performed, and the presence of USA300-associated toxins and the arcA gene was investigated for all isolates categorized as CA-MRSA. A total of 1570 S. aureus were included; 651 were MRSA (41%)--with the highest rate of MRSA isolation in Peru (62%) and the lowest in Venezuela (26%)--and 71%, 27%, and 2% were classified as HA-like, CA-like, and non-CA/HA-like clones, respectively. Only 9 MRSA isolates were confirmed to have reduced susceptibility to glycopeptides (glycopeptide-intermediate S. aureus phenotype). The most common pulsotype (designated ComA) among the CA-like MRSA strains was found in 96% of isolates, with the majority (81%) having a < or =6-band difference with the USA300-0114 strain. Representative isolates of this clone were sequence type 8; however, unlike the USA300-0114 strain, they harbored a different SCCmec IV subtype and lacked arcA (an indicator of the arginine catabolic mobile element). A variant CA-MRSA USA300 clone has become established in South America and, in some countries, is endemic in hospital settings.

Influence of Methicillin-Resistant Staphylococcus aureus Carrier Status in Liver Transplant Recipients

The prevalence of methicillin-resistant Staphylococus aureus (MRSA) has increased worldwide and MRSA has emerged as an important cause of sepsis in cirrhotic patients and liver transplant recipients. In this retrospective study, the prevalence of MRSA colonization and its influence on infections following orthotopic liver transplantation (OLT) was investigated. From August, 2002 until November, 2004, 66 primary cadaver OLT were performed for adult recipients. Antibody induction used Daclizumab ( n = 49) or ATG ( n = 14). Maintenance immunosuppression consisted of tacrolimus and steroids, with 30 patients receiving mycophenolate mofetil and 4, rapamune. For perioperative anti-infectious prophylaxis cefotaxime, metronidazole, and tobramycin were administered for 48 hours. The preoperatively performed routine swabs revealed MRSA colonization in 12 of 66 (18.2%) patients. The stage of cirrhosis was equivalent for MRSA(−) patients according to Child score. The mean MELD score was significantly higher for MRSA(+) patients (24.3 versus 18.7, P = .036). More MRSA(+) patients were hospitalized at the time of transplantation (14/54 versus 8/12, P = .018). The incidence of posttransplant infections was not significantly different among the two groups. Within the first year 7 of 66 (10.6%) patients died: 3 of 12 (25%) MRSA(+) and 4 of 54 (7.4%) MRSA(−). The 1-year survival was lower in the MRSA(+) group (74.1% versus 94.1%). In conclusion, this study did not show that an MRSA-positive carrier status implies an increased risk for septic complications following OLT. Mortality was increased for MRSA(+), but failed to show a significant difference. A significantly higher MELD score and pretransplant hospitalization for MRSA(+) patients may contribute to the higher mortality and reflect sicker patients.

Clinical and radiographic spectrum of septic pulmonary embolism

Aims: To review the clinical presentation, radiographic findings, and outcome of therapy in children with septic pulmonary embolism. Methods: Retrospective analysis of patients in a tertiary paediatric facility in northern...

Commons told of MRSA cover-up.

THE RCN has defended hospitals from an MP's claims of a cover-up of thousands of deaths from methicillin-resistant Staphylococus aureus (MRSA).

A CASE OF TOXIC SHOCK SYNDROME CAUSED BY METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS AFTER APPENDECTOMY

Staphylococcus causing toxic shock syndrome (TSS) in the surgical field is Methicillin-resistant Staphylococus aureus (MRSA) in most cases. Postoperative MRSA is an important factor to provoke TSS. Postoperative MRSA infection has been speculated mostly as a result of the prophylactic use of third-generation cephems on the immunologically compromised patient. However, the virulence of the bacteria may possibly overpower the defence mechanism of the host who has undergone minimum surgical stress. Recently we experienced an adult male patient with non-perforated acute appendicitis who developed MRSA peritonitis after an appendectomy causing TSS in an acute clinical course. We have reconfirmed that even patient without any risk factors can develop MRSA infection followed by TSS, if things come to the worst. The importance of the careful monitoring and management of postoperative MRSA infection even after the less invasive abdominal surgery should be emphasized.