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Sample records for haematogenous staphylococcus aureus

  1. Beneficial effect of glucocorticoids on the course of haematogenously acquired Staphylococcus aureus nephritis.

    PubMed

    Verba, V; Sakiniene, E; Tarkowski, A

    1997-03-01

    The effect of combined antibiotic and corticosteroid treatment on the course of haematogenously acquired Staphylococcus aureus nephritis was studied. Mice were given a single injection of S. aureus producing toxic shock syndrome toxin-1 in a dose capable of inducing a high frequency of inflammatory kidney lesions and divided into three groups according to a treatment regimen. In all untreated animals inflammatory infiltrates were seen in kidney cortex and medulla with high frequencies of glomerular (90%) and tubular damage (50%) as well as fibrotic changes (50%). The treatment with antibiotics alone reduced significantly only the occurrence of focal inflammatory infiltrates. In contrast, the mice treated with a combination of antibiotics and corticosteroids displayed in 64% of cases normal histological kidney appearance and a significant decrease in occurrence of glomerular (P<0.01) and tubular (P<0.05) lesions. Immunohistochemically, the combined treatment resulted in a more pronounced decrease in numbers of CD4, IL-2R (four to fivefold) and CD8 positive cells in kidney inflammatory lesions compared to antibiotics only treated group. Thus, glucocorticoids in association with antibiotics are shown to improve the outcome of septic murine nephritis, possibly due to suppression of kidney infiltrating T cells.

  2. Participation of V beta 4(+)-, V beta 7(+)-, and V beta 11(+)-T lymphocytes in haematogenously acquired Staphylococcus aureus nephritis.

    PubMed

    Verba, V; Tarkowski, A

    1996-09-01

    The most frequent pathogen in haematogenously acquired kidney infections in humans in Staphylococcus aureus. In order to characterize in situ the immunological patterns of septic nephritis we developed a murine model of this disease. A single intravenous injection of S. aureus producing toxic shock syndrome toxin-1 resulted in high frequency of inflammatory kidney lesions. Histopathologically, both focal and diffuse inflammatory infiltrates were seen in kidney cortex and medulla. Immunohistochemical evaluation revealed high numbers of Mac-1+ phagocytic cells as well as CD4(+)-and CD8(+)-lymphocytes. The expansion of lymphocytes carrying T-cell receptor V beta chain 4, 7, and 11 families in the kidney was observed. Our results suggest that the haematogenously acquired kidney infection by superantigen-producing staphylococci leads to migration, in situ activation and expansion of responding T-lymphocyte subsets.

  3. Acute haematogenous community-acquired methicillin-resistant Staphylococcus aureus osteomyelitis in an adult: Case report and review of literature

    PubMed Central

    2012-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) has of late emerged as a cause of community-acquired infections among immunocompetent adults without risk factors. Skin and soft tissue infections represent the majority of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) clinical presentations, whilst invasive and life-threatening illness like necrotizing pneumonia, necrotizing fasciitis, pyomyositis, osteomyelitis and sepsis syndrome are less common. Although more widely described in the pediatric age group, the occurrence of CA-MRSA osteomyelitis in adults is an uncommonly reported entity. Case presentation We describe an invasive CA-MRSA infection in a 28 year-old previously healthy male, manifesting with bacteraemia, osteomyelitis of femur, pyomyositis and septic arthritis of the knee. Initially a preliminary diagnosis of osteosarcoma was suggested by imaging studies and patient underwent a bone biopsy. MRSA was subsequently isolated from blood cultures taken on day of admission, bone, tissue and pus cultures. Incision and drainage of abscess was performed and patient was treated with vancomycin, with fusidic acid added later. It took 6 months for the inflammatory markers to normalize, warranting 6-months of anti-MRSA therapy. Patient was a fervent deer hunter and we speculate that he acquired this infection from extensive direct contact with deer. Molecular characterization of this isolate showed that it belonged to multilocus sequence type (MLST) ST30 and exhibited the staphylococcal chromosome cassette mec (SCCmec) type IV, staphylococcus protein A (spa) type t019, accessory gene regulator (agr) type III and dru type dt10m. This strain harbored Panton-Valentine leukocidin (pvl) genes together with 3 other virulent genes; sei (enterotoxin), hlg (hemolysin) and fnbA (fibronectin binding protein). Conclusion This case study alerts physicians that beyond the most commonly encountered skin and soft tissue infections, pvl

  4. Comparison of autologous 111In-leukocytes, 18F-FDG, 11C-methionine, 11C-PK11195 and 68Ga-citrate for diagnostic nuclear imaging in a juvenile porcine haematogenous staphylococcus aureus osteomyelitis model

    PubMed Central

    Nielsen, Ole L; Afzelius, Pia; Bender, Dirk; Schønheyder, Henrik C; Leifsson, Páll S; Nielsen, Karin M; Larsen, Jytte O; Jensen, Svend B; Alstrup, Aage KO

    2015-01-01

    The aim of this study was to compare 111In-labeled leukocyte single-photon emission computed tomography (SPECT) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) to PET with tracers that potentially could improve detection of osteomyelitis. We chose 11C-methionine, 11C-PK11195 and 68Ga-citrate and validated their diagnostic utility in a porcine haematogenous osteomyelitis model. Four juvenile 14-15 weeks old female pigs were scanned seven days after intra-arterial inoculation in the right femoral artery with a porcine strain of Staphylococcus aureus using a sequential scan protocol with 18F-FDG, 68Ga-citrate, 11C-methionine, 11C-PK11195, 99mTc-Nanocoll and 111In-labelled autologous leukocytes. This was followed by necropsy of the pigs and gross pathology, histopathology and microbial examination. The pigs developed a total of five osteomyelitis lesions, five lesions characterized as abscesses/cellulitis, arthritis in three joints and five enlarged lymph nodes. None of the tracers accumulated in joints with arthritis. By comparing the 10 infectious lesions, 18F-FDG accumulated in nine, 111In-leukocytes in eight, 11C-methionine in six, 68Ga-citrate in four and 11C-PK11195 accumulated in only one lesion. Overall, 18F-FDG PET was superior to 111In-leukocyte SPECT in marking infectious and proliferative, i.e. hyperplastic, lesions. However, leukocyte SPECT was performed as early scans, approximately 6 h after injection of the leukocytes, to match the requirements of the 18 h long scan protocol. 11C-methionine and possibly 68Ga-citrate may be useful for diagnosis of soft issue lesions. PMID:25973338

  5. Staphylococcus aureus and Pregnancy

    MedlinePlus

    Staphylococcus aureus (Staph Infection) In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a ... from your health care provider. What is a staph infection? Staphylococcus aureus (staph) is a type of bacteria ( ...

  6. Staphylococcus aureus toxins.

    PubMed

    Otto, Michael

    2014-02-01

    Staphylococcus aureus is a dangerous pathogen that causes a variety of severe diseases. The virulence of S. aureus is defined by a large repertoire of virulence factors, among which secreted toxins play a preeminent role. Many S. aureus toxins damage biological membranes, leading to cell death. In particular, S. aureus produces potent hemolysins and leukotoxins. Among the latter, some were recently identified to lyse neutrophils after ingestion, representing an especially powerful weapon against bacterial elimination by innate host defense. Furthermore, S. aureus secretes many factors that inhibit the complement cascade or prevent recognition by host defenses. Several further toxins add to this multi-faceted program of S. aureus to evade elimination in the host. This review will give an overview over S. aureus toxins focusing on recent advances in our understanding of how leukotoxins work in receptor-mediated or receptor-independent fashions. Published by Elsevier Ltd.

  7. Staphylococcus aureus biofilms

    PubMed Central

    Archer, Nathan K; Mazaitis, Mark J; Costerton, J William; Leid, Jeff G; Powers, Mary Elizabeth

    2011-01-01

    Increasing attention has been focused on understanding bacterial biofilms and this growth modality's relation to human disease. In this review we explore the genetic regulation and molecular components involved in biofilm formation and maturation in the context of the Gram-positive cocci, Staphylococcus aureus. In addition, we discuss diseases and host immune responses, along with current therapies associated with S. aureus biofilm infections and prevention strategies. PMID:21921685

  8. The Staphylococcus aureus "superbug".

    PubMed

    Foster, Timothy J

    2004-12-01

    There has been some debate about the disease-invoking potential of Staphylococcus aureus strains and whether invasive disease is associated with particularly virulent genotypes, or "superbugs." A study in this issue of the JCI describes the genotyping of a large collection of nonclinical, commensal S. aureus strains from healthy individuals in a Dutch population. Extensive study of their genetic relatedness by amplified restriction fragment typing and comparison with strains that are associated with different types of infections revealed that the S. aureus population is clonal and that some strains have enhanced virulence. This is discussed in the context of growing interest in the mechanisms of bacterial colonization, antibiotic resistance, and novel vaccines.

  9. Atopic dermatitis and Staphylococcus aureus.

    PubMed

    Arslanagic, Naima; Arslanagic, Rusmir

    2004-01-01

    Atopic dermatitis is chronic, pruritic inflammatory skin disorder strongly influenced by environmental factors. Staplylococcus aurcus is the common pathogen and colonize the normal skin but it is not number of normal skin flora. Damaged protective skin function by atopic dermatitis, the disturbance of quantity and quality of lipids of stratum corneum are some of the reasons for increasing degree of skin colonisation with staphylococcus aureus. We had presented frequency of the isolation staphylococcus aureus from eczematous atopic skin, from the nose and throat of atopic patients and also from clinically unaffected atopic skin in the group of 30 children compared with 15 healthy children without positive atopic family history. Staphylococcus aureus had been significantly more isolated by all earlier mentioned places in atopic group of children. There is a direct correlation between intensity and also extensity of atopic dermatitis and frequency of the isolation of staphylococcus aureus from mentioned places. The role of staphylococcus aureus in pathogenesis of atopic dermatitis was discussed.

  10. Staphylococcus aureus bacteremia.

    PubMed

    Jensen, Allan Garlik

    2003-11-01

    Staphylococcus aureus bacteremia (SAB) is still associated with a high mortality, and knowledge on risk factors and the clinical and the therapeutic aspects of SAB is still limited. This thesis focuses on the clinical aspects of SAB and its metastatic infections. In a study of all patients with bacteremia in Copenhagen County October 1992 through April 1993 (study I) we emphasized previous findings, that S. aureus is one of the most frequent pathogens in bacteremia, and in a case control study also in Copenhagen County 1994-95 (study II) we demonstrated, that not only an inserted central venous catheter and nasal S. aureus carriage but also hyponatremia and anemia are important risk factors for hospital-acquired SAB (study II). Studies on the treatment of SAB have pointed out, that the eradication of a primary is important, but there are only limited clinical studies dealing with antibiotic treatment. By logistic regression analysis, we were able to demonstrate that focus eradication is essential, but also that treatment with dicloxacillin 1 g x 4 or 2 g x 3 are superior to 1 g x 3 (studie III), indicating that the time for serum concentration above the Minimal Inhibitory Concentration (MIC) for the bacteria plays a role in the outcome of SAB treatment. S. aureus osteomyelitis secondary to SAB is frequently observed. No other countries, however, have a centralized registration, which make it possible to evaluate a large number of these patients. Since 1960, The Staphylococcal Laboratory, Statens Serum Institut in Copenhagen, has registrated selected clinical informations from nearly all patients with positive blood cultures of S. aureus. Based on this registration, we were able to show an increased number of S. aureus osteomyelitis among older patients and a decreased number of S. aureus osteomyelitis of femur and tibia among younger infants in the period 1980-90 (study IV). By reviewing the records of a large number of patients with vertebral S. aureus

  11. Evolving Superantigens of Staphylococcus Aureus

    DTIC Science & Technology

    2000-01-01

    1993) Phenotypic char- acterization of xpr, a global regulator of extracellular virulence fac- tors in Staphylococcus aureus. Infect . Immun. 61, 919...tional fusions as the detection system in the rabbit endocarditis mod- el. Infect . Immun. 66, 5988-5993. [35] Wieneke, A.A., Roberts, D. and... Infections Diseases, 1425 Porter Street, Frederick, MD 21702, USA Received 24 March 1999; accepted 14 April 1999 Abstract Staphylococcus aureus

  12. [Protein toxins of Staphylococcus aureus].

    PubMed

    Shamsutdinov, A F; Tiurin, Iu A

    2014-01-01

    Main scientific-research studies regarding protein bacterial toxins of the most widespread bacteria that belong to Staphylococcus spp. genus and in particular the most pathogenic species for humans--Staphylococcus aureus, are analyzed. Structural and biological properties of protein toxins that have received the name of staphylococcus pyrogenic toxins (PTSAg) are presented. Data regarding genetic regulation of secretion and synthesis of these toxins and 3 main regulatory genetic systems (agr--accessory gene regulator, xpr--extracellular protein regulator, sar--staphylococcal accessory regulator) that coordinate synthesis of the most important protein toxins and enzymes for virulence of S. aureus, are presented.

  13. Staphylococcus aureus: a community pathogen.

    PubMed

    Miller, Loren G; Kaplan, Sheldon L

    2009-03-01

    Staphylococcus aureus is a common human pathogen. S aureus infections most commonly clinically manifest as skin infections. There has been much interest in S aureus infections in the community over the past decade because of the rise of community-associated methicillin-resistant S aureus (CA-MRSA) infections, which have emerged globally over a relatively short period of time. In contrast to health care-associated methicillin resistant S aureus (HA-MRSA), circulating strains of CA-MRSA have characteristic pathogenesis, strain characteristics, epidemiology, and clinical manifestations that are distinct from HA-MRSA. In fact, CA-MRSA probably behaves more like community-associated methicillin-sensitive S aureus (MSSA). This article reviews current knowledge of the epidemiology and clinical manifestations of community-associated S aureus and CA-MRSA infections.

  14. Methicillin-resistant Staphylococcus aureus (MRSA)

    MedlinePlus

    Methicillin-resistant Staphylococcus aureus; Hospital-acquired MRSA (HA-MRSA); Staph - MRSA; Staphylococcal - MRSA ... Que YA, Moreillon P. Staphylococcus aureus (including ... MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice ...

  15. Staphylococcus aureus: superbug, super genome?

    PubMed

    Lindsay, Jodi A; Holden, Matthew T G

    2004-08-01

    Staphylococcus aureus is a common cause of infection in both hospitals and the community, and it is becoming increasingly virulent and resistant to antibiotics. The recent sequencing of seven strains of S. aureus provides unprecedented information about its genome diversity. Subtle differences in core (stable) regions of the genome have been exploited by multi-locus sequence typing (MLST) to understand S. aureus population structure. Dramatic differences in the carriage and spread of accessory genes, including those involved in virulence and resistance, contribute to the emergence of new strains with healthcare implications. Understanding the differences between S. aureus genomes and the controls that govern these changes is helping to improve our knowledge of S. aureus pathogenicity and to predict the evolution of super-superbugs.

  16. [Vancomycin-resistant Staphylococcus aureus].

    PubMed

    Rodríguez, Carlos Andrés; Vesga, Omar

    2005-12-01

    The evolution and molecular mechanisms of vancomycin resistance in Staphylococcus aureus were reviewed. Case reports and research studies on biochemestry, electron microscopy and molecular biology of Staphylococcus aureus were selected from Medline database and summarized in the following review. After almost 40 years of successful treatment of S. aureus with vancomycin, several cases of clinical failures have been reported (since 1997). S. aureus strains have appeared with intermediate susceptibility (MIC 8-16 microg/ml), as well as strains with heterogeneous resistance (global MIC < or =4 microg/ml), but with subpopulations of intermediate susceptibility. In these cases, resistance is mediated by cell wall thickening with reduced cross linking. This traps the antibiotic before it reaches its major target, the murein monomers in the cell membrane. In 2002, a total vancomycin resistant strain (MIC > or =32 microg/ml) was reported with vanA genes from Enterococcus spp. These genes induce the change of D-Ala-D-Ala terminus for D-Ala-D-lactate in the cell wall precursors, leading to loss of affinity for glycopeptides. Vancomycin resistance in S. aureus has appeared; it is mediated by cell wall modifications that trap the antibiotic before it reaches its action site. In strains with total resistance, Enterococcus spp. genes have been acquired that lead to modification of the glycopeptide target.

  17. Pathogenesis of Staphylococcus aureus abscesses.

    PubMed

    Kobayashi, Scott D; Malachowa, Natalia; DeLeo, Frank R

    2015-06-01

    Staphylococcus aureus causes many types of human infections and syndromes-most notably skin and soft tissue infections. Abscesses are a frequent manifestation of S. aureus skin and soft tissue infections and are formed, in part, to contain the nidus of infection. Polymorphonuclear leukocytes (neutrophils) are the primary cellular host defense against S. aureus infections and a major component of S. aureus abscesses. These host cells contain and produce many antimicrobial agents that are effective at killing bacteria, but can also cause non-specific damage to host tissues and contribute to the formation of abscesses. By comparison, S. aureus produces several molecules that also contribute to the formation of abscesses. Such molecules include those that recruit neutrophils, cause host cell lysis, and are involved in the formation of the fibrin capsule surrounding the abscess. Herein, we review our current knowledge of the mechanisms and processes underlying the formation of S. aureus abscesses, including the involvement of polymorphonuclear leukocytes, and provide a brief overview of therapeutic approaches.

  18. Adaptive Immunity Against Staphylococcus aureus.

    PubMed

    Karauzum, Hatice; Datta, Sandip K

    2016-02-27

    A complex interplay between host and bacterial factors allows Staphylococcus aureus to occupy its niche as a human commensal and a major human pathogen. The role of neutrophils as a critical component of the innate immune response against S. aureus, particularly for control of systemic infection, has been established in both animal models and in humans with acquired and congenital neutrophil dysfunction. The role of the adaptive immune system is less clear. Although deficiencies in adaptive immunity do not result in the marked susceptibility to S. aureus infection that neutrophil dysfunction imparts, emerging evidence suggests both T cell- and B cell-mediated adaptive immunity can influence host susceptibility and control of S. aureus. The contribution of adaptive immunity depends on the context and site of infection and can be either beneficial or detrimental to the host. Furthermore, S. aureus has evolved mechanisms to manipulate adaptive immune responses to its advantage. In this chapter, we will review the evidence for the role of adaptive immunity during S. aureus infections. Further elucidation of this role will be important to understand how it influences susceptibility to infection and to appropriately design vaccines that elicit adaptive immune responses to protect against subsequent infections.

  19. Staphylococcus aureus and sore nipples.

    PubMed Central

    Livingstone, V. H.; Willis, C. E.; Berkowitz, J.

    1996-01-01

    OBJECTIVE: To correlate clinical symptoms and signs of sore nipples with the presence of Staphylococcus aureus and to determine the probability of mothers having S aureus-infected nipples when these local symptoms and signs are found. DESIGN: Two cohorts of consecutive patients were enrolled regardless of presenting complaint. A questionnaire was administered to determine the presence and severity of sore nipples. Objective findings on breast examination were documented. A nipple swab was taken for culture and sensitivity. SETTING: Breastfeeding clinic serving patients referred by family physicians, pediatricians, and community health nurses. PATIENTS: A sample of 227 breastfeeding mothers was collected in two cohorts. MAIN OUTCOME MEASURES: Answers to questions about sore nipples, objective findings from physical examination, and results from nipple swabs. RESULTS: Most subjects (51%) had sore nipples, and 45% of subjects had objective findings on examination; 23% of subjects had a positive nipple swab culture; 15% grew S aureus on culture. The risk of having S aureus colonization was 4.8 times greater if nipple pain was moderate or severe rather than mild. A break in nipple integument associated with cracks, fissures, ulcers, or pus gave a 35% chance of having S aureus colonization, five times greater than when the integument was intact. CONCLUSIONS: The study showed that mothers with infants younger than 1 month who complained of moderate to severe nipple pain and who had cracks, fissures, ulcers, or exudates had a 64% chance of having positive skin cultures and a 54% chance of having S aureus colonization. PMID:8653033

  20. CHROMOSOMAL MAPPING IN STRAINS OF STAPHYLOCOCCUS AUREUS,

    DTIC Science & Technology

    STAPHYLOCOCCUS AUREUS , CHROMOSOMES), (*CHROMOSOMES, MAPPING), NITROSO COMPOUNDS, GUANIDINES, GENETICS, MUTATIONS, DRUGS, TOLERANCES(PHYSIOLOGY), TEST METHODS, DEOXYRIBONUCLEIC ACIDS, INHIBITION, RESISTANCE(BIOLOGY).

  1. Staphylococcus aureus in rural drinking water.

    PubMed Central

    LeChevallier, M W; Seidler, R J

    1980-01-01

    Coagulase-positive Staphylococcus aureus was isolated from over 6% of 320 rural drinking water specimens. Well water was the most common source examined. The presence of S. aureus was not found to correlate with the presence of coliform bacteria. Strains of Staphylococcus that produced enterotoxin A were found in 40% of the samples containing S. aureus. Additional studies showed that faucet aerator screens were common sources of high cell densities of S. aureus. PMID:7377774

  2. Collagen binding to Staphylococcus aureus

    SciTech Connect

    Holderbaum, D.; Hall, G.S.; Ehrhart, L.A.

    1986-11-01

    Staphylococcus aureus can bind soluble collagen in a specific, saturable manner. We have previously shown that some variability exists in the degree of collagen binding between different strains of heat-killed, formaldehyde-fixed S. aureus which are commercially available as immunologic reagents. The present study demonstrates that live S. aureus of the Cowan 1 strain binds amounts of collagen per organism equivalent to those demonstrated previously in heat-killed, formaldehyde-fixed bacteria but has an affinity over 100 times greater, with Kd values of 9.7 X 10(-11) M and 4.3 X 10(-8) M for live and heat-killed organisms, respectively. Studies were also carried out with S. aureus killed by ionizing radiation, since this method of killing the organism seemed less likely to alter the binding moieties on the surface than did heat killing. Bacteria killed by exposure to gamma radiation bound collagen in a manner essentially indistinguishable from that of live organisms. Binding of collagen to irradiated cells of the Cowan 1 strain was rapid, with equilibrium reached by 30 min at 22 degrees C, and was fully reversible. The binding was not inhibited by fibronectin, fibrinogen, C1q, or immunoglobulin G, suggesting a binding site for collagen distinct from those for these proteins. Collagen binding was virtually eliminated in trypsin-treated organisms, indicating that the binding site has a protein component. Of four strains examined, Cowan 1 and S. aureus ATCC 25923 showed saturable, specific binding, while strains Woods and S4 showed a complete lack of binding. These results suggest that some strains of S. aureus contain high-affinity binding sites for collagen. While the number of binding sites per bacterium varied sixfold in the two collagen-binding strains, the apparent affinity was similar.

  3. Methicillin resistant Staphylococcus aureus - an overview.

    PubMed

    Haque, N; Bari, M S; Bilkis, L; Haque, N; Haque, S; Sultana, S

    2011-01-01

    Staphylococcus aureus strains those are resistant to methicillin are referred to as Methicillin resistant Staphylococcus aureus. These express mecA gene to produce altered penicillin binding protein. At present Methicillin resistant Staphylococcus aureus has been increasing as a serious nosocomial and community pathogen having the property of multi drug resistant. Humans are the natural reservoir for Staphylococcus aureus and asymptomatic colonization is far more common than infection. Many hospitals of different country of the world including Bangladesh are struggling with increasing number of this versatile pathogen. Early and specific diagnosis is important to ensure a favourable outcome. In this paper we attempted to explore history, prevalence, transmission, risk factors, pathogenicity, laboratory diagnosis, prevention and control of Methicillin resistant Staphylococcus aureus as a critical review to provide some new upgrade regarding this super bug.

  4. Fluorescent Reporters for Staphylococcus aureus

    PubMed Central

    Malone, Cheryl L.; Boles, Blaise R.; Lauderdale, Katherine J.; Thoendel, Matthew; Kavanaugh, Jeffrey S.; Horswill, Alexander R.

    2009-01-01

    With the emergence of Staphylococcus aureus as a prominent pathogen in community and healthcare settings, there is a growing need for effective reporter tools to facilitate physiology and pathogenesis studies. Fluorescent proteins are ideal as reporters for their convenience in monitoring gene expression, performing host interaction studies, and monitoring biofilm growth. We have developed a suite of fluorescent reporter plasmids for labeling S. aureus cells. These plasmids encode either green fluorescent protein (GFP) or higher wavelength reporter variants for yellow (YFP) and red (mCherry) labeling. The reporters were placed under control of characterized promoters to enable constitutive or inducible expression. Additionally, plasmids were assembled with fluorescent reporters under control of the agr quorum-sensing and Sigma factor B promoters, and the fluorescent response with wildtype and relevant mutant strains was characterized. Interestingly, reporter expression displayed a strong dependence on ribosome binding site (RBS) sequence, with the superoxide dismutase RBS displaying the strongest expression kinetics of the sequences examined. To test the robustness of the reporter plasmids, cell imaging was performed with fluorescence microscopy and cell populations were separated using florescence activated cell sorting (FACS), demonstrating the possibilities of simultaneous monitoring of multiple S. aureus properties. Finally, a constitutive YFP reporter displayed stable, robust labeling of biofilm growth in a flow cell apparatus. This toolbox of fluorescent reporter plasmids will facilitate cell labeling for a variety of different experimental applications. PMID:19264102

  5. Desiccation tolerance in Staphylococcus aureus.

    PubMed

    Chaibenjawong, Plykaeow; Foster, Simon J

    2011-02-01

    Staphylococcus aureus is a multidrug-resistant pathogen that not only causes a diverse array of human diseases, but also is able to survive in potentially dry and stressful environments, such as the human nose, on skin and on inanimate surfaces such as clothing and surfaces. This study investigated parameters governing desiccation tolerance of S. aureus and identified several components involved in the process. Initially, the role of environmental parameters such as temperature, growth phase, cell density, desiccation time and protectants in desiccation tolerance were determined. This established a robust model of desiccation tolerance in which S. aureus has the ability to survive on dry plastic surfaces for more than 1,097 days. Using a combination of a random screen and defined mutants, clpX, sigB and yjbH were identified as being required for desiccation tolerance. ClpX is a part of the ATP-dependent ClpXP protease, important for protein turnover, and YjbH has a proposed linked function. SigB is an accessory sigma factor with a role in generalized stress resistance. Understanding the molecular mechanisms that govern desiccation tolerance may determine the break points to be exploited to prevent the spread of this dangerous pathogen in hospitals and communities.

  6. Colony spreading in Staphylococcus aureus.

    PubMed

    Kaito, Chikara; Sekimizu, Kazuhisa

    2007-03-01

    Wild-type Staphylococcus aureus rapidly expands on the surface of soft agar plates. The rates of expansion and the shapes of the resultant giant colonies were distinct for different strains of laboratory stocks and clinical isolates. The colony spreading abilities did not correlate with the biofilm-forming abilities in these strains. Insertional disruption of the dltABCD operon, which functions at the step of D-alanine addition to teichoic acids, and of the tagO gene, which is responsible for the synthesis of wall teichoic acids, decreased the colony spreading ability. The results indicate that wall teichoic acids and D-alanylation of teichoic acids are required for colony spreading.

  7. Exfoliative Toxins of Staphylococcus aureus

    PubMed Central

    Bukowski, Michal; Wladyka, Benedykt; Dubin, Grzegorz

    2010-01-01

    Staphylococcus aureus is an important pathogen of humans and livestock. It causes a diverse array of diseases, ranging from relatively harmless localized skin infections to life-threatening systemic conditions. Among multiple virulence factors, staphylococci secrete several exotoxins directly associated with particular disease symptoms. These include toxic shock syndrome toxin 1 (TSST-1), enterotoxins, and exfoliative toxins (ETs). The latter are particularly interesting as the sole agents responsible for staphylococcal scalded skin syndrome (SSSS), a disease predominantly affecting infants and characterized by the loss of superficial skin layers, dehydration, and secondary infections. The molecular basis of the clinical symptoms of SSSS is well understood. ETs are serine proteases with high substrate specificity, which selectively recognize and hydrolyze desmosomal proteins in the skin. The fascinating road leading to the discovery of ETs as the agents responsible for SSSS and the characterization of the molecular mechanism of their action, including recent advances in the field, are reviewed in this article. PMID:22069631

  8. Exfoliative toxins of Staphylococcus aureus.

    PubMed

    Bukowski, Michal; Wladyka, Benedykt; Dubin, Grzegorz

    2010-05-01

    Staphylococcus aureus is an important pathogen of humans and livestock. It causes a diverse array of diseases, ranging from relatively harmless localized skin infections to life-threatening systemic conditions. Among multiple virulence factors, staphylococci secrete several exotoxins directly associated with particular disease symptoms. These include toxic shock syndrome toxin 1 (TSST-1), enterotoxins, and exfoliative toxins (ETs). The latter are particularly interesting as the sole agents responsible for staphylococcal scalded skin syndrome (SSSS), a disease predominantly affecting infants and characterized by the loss of superficial skin layers, dehydration, and secondary infections. The molecular basis of the clinical symptoms of SSSS is well understood. ETs are serine proteases with high substrate specificity, which selectively recognize and hydrolyze desmosomal proteins in the skin. The fascinating road leading to the discovery of ETs as the agents responsible for SSSS and the characterization of the molecular mechanism of their action, including recent advances in the field, are reviewed in this article.

  9. Comparative Efficacy of Ceftaroline with Linezolid against Staphylococcus aureus and Methicillin Resistant Staphylococcus aureus.

    PubMed

    Hafeez, Amira; Munir, Tehmina; Rehman, Sabahat; Najeeb, Sara; Gilani, Mehreen; Latif, Mahwish; Ansari, Maliha; Saad, Nadia

    2015-04-01

    To compare the in vitro antimicrobial efficacy of ceftaroline with linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Quasi-experimental study. Microbiology Department, Army Medical College, Rawalpindi, from January to December 2013. Clinical samples from respiratory tract, blood, pus and various catheter tips routinely received in the Department of Microbiology, Army Medical College, Rawalpindi were innoculated on blood and MacConkey agar. Staphylococcus aureus was identified by colony morphology, Gram reaction, catalase test and coagulase test. Methicillin resistant Staphylococcus aureus detection was done by modified Kirby Bauer disc diffusion method using cefoxitin disc (30 μg) and the isolates were considered methicillin resistant if the zone of inhibition around cefoxitin disc was ≤ 21 mm. Bacterial suspensions of 56 Staphylococcus aureus isolates and 50 MRSA isolates were prepared, which were standardized equal to 0.5 McFarland's turbidity standard and inoculated on Mueller-Hinton agar plates followed by application of ceftaroline and linezolid disc (Oxoid, UK), according to manufacturer's instructions. The plates were then incubated at 37 °C aerobically for 18 - 24 hours. Diameters of inhibition zone were measured and interpretated as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Out of 106 isolates all of the 56 Staphylococcus aureus (100%) were sensitive to ceftaroline and linezolid. However, out of 50 methicillin resistant Staphylococcus aureus, 48 (96%) were sensitive to ceftaroline whereas, 49 (98%) were sensitive to linezolid. Ceftaroline is equally effective as linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus.

  10. Complement depletion aggravates Staphylococcus aureus septicaemia and septic arthritis

    PubMed Central

    Sakiniene, E; Bremell, T; Tarkowski, A

    1999-01-01

    The aim of the study was to assess the role of the complement system in Staphylococcus aureus arthritis and septicaemia. The murine model of haematogenously acquired septic arthritis was used, injecting intravenously toxic shock syndrome toxin-1 (TSST-1), producing S. aureus LS-1. Complement was depleted using cobra venom factor (CVF). Evaluation of arthritis was performed clinically and histopathologically. In addition, the effect of complement depletion on the phagocytic activity of leucocytes was assessed in vivo and in vitro. Six days after inoculation of S. aureus the prevalence of arthritis in decomplemented mice was three-fold higher than that in controls (91% versus 25%). The clinical severity of arthritis at the end of the experiment, expressed as arthritic index, was 7.3 and 1.9, respectively. These findings were confirmed by histological index of synovitis as well as of cartilage and/or bone destruction being significantly higher in decomplemented mice than in controls (9.8 ± 1.7 versus 4.9 ± 1.2, P < 0.05; and 7.9 ± 1.7 versus 3.0 ± 0.9, P < 0.05, respectively). Also, the septicaemia-induced mortality was clearly higher in decomplemented mice compared with the controls. CVF treatment significantly reduced in vivo polymorphonuclear cell-dependent inflammation induced by subcutaneous injection of olive oil and mirroring the capacity of polymorphonuclear cells (PMNC) to migrate and/or extravasate. Besides, the decomplementation procedure significantly impaired phagocytic activity of peripheral blood leucocytes in vitro, since the number of phagocytes being able to ingest bacteria decreased by 50% when the cells were maintained in decomplemented serum compared with those in intact serum. The conclusion is that complement depletion aggravates the clinical course of S. aureus arthritis and septicaemia, possibly by a combination of decreased migration/extravasation of PMNC and an impairment of phagocytosis. PMID:9933426

  11. Catheter-associated Staphylococcus aureus bacteremia.

    PubMed

    Gold, H S; Karchmer, A W

    1996-09-15

    The majority of cases of Staphylococcus aureus bacteremia are hospital-acquired, and most are associated with infected intravenous catheters. Preventive measures, early detection of infections, and strategies for effective treatment have become matters of increasing urgency.

  12. How Clonal Is Staphylococcus aureus?

    PubMed Central

    Feil, Edward J.; Cooper, Jessica E.; Grundmann, Hajo; Robinson, D. Ashley; Enright, Mark C.; Berendt, Tony; Peacock, Sharon J.; Smith, John Maynard; Murphy, Michael; Spratt, Brian G.; Moore, Catrin E.; Day, Nicholas P. J.

    2003-01-01

    Staphylococcus aureus is an important human pathogen and represents a growing public health burden owing to the emergence and spread of antibiotic-resistant clones, particularly within the hospital environment. Despite this, basic questions about the evolution and population biology of the species, particularly with regard to the extent and impact of homologous recombination, remain unanswered. We address these issues through an analysis of sequence data obtained from the characterization by multilocus sequence typing (MLST) of 334 isolates of S. aureus, recovered from a well-defined population, over a limited time span. We find no significant differences in the distribution of multilocus genotypes between strains isolated from carriers and those from patients with invasive disease; there is, therefore, no evidence from MLST data, which index variation within the stable “core” genome, for the existence of hypervirulent clones of this pathogen. Examination of the sequence changes at MLST loci during clonal diversification shows that point mutations give rise to new alleles at least 15-fold more frequently than does recombination. This contrasts with the naturally transformable species Neisseria meningitidis and Streptococcus pneumoniae, in which alleles change between 5- and 10-fold more frequently by recombination than by mutation. However, phylogenetic analysis suggests that homologous recombination does contribute toward the evolution of this species over the long term. Finally, we note a striking excess of nonsynonymous substitutions in comparisons between isolates belonging to the same clonal complex compared to isolates belonging to different clonal complexes, suggesting that the removal of deleterious mutations by purifying selection may be relatively slow. PMID:12754228

  13. Immunomodulation and Disease Tolerance to Staphylococcus aureus

    PubMed Central

    Li, Zhigang; Peres, Adam G.; Damian, Andreea C.; Madrenas, Joaquín

    2015-01-01

    The Gram-positive bacterium Staphylococcus aureus is one of the most frequent pathogens that causes severe morbidity and mortality throughout the world. S. aureus can infect skin and soft tissues or become invasive leading to diseases such as pneumonia, endocarditis, sepsis or toxic shock syndrome. In contrast, S. aureus is also a common commensal microbe and is often part of the human nasal microbiome without causing any apparent disease. In this review, we explore the immunomodulation and disease tolerance mechanisms that promote commensalism to S. aureus. PMID:26580658

  14. Evasion of Neutrophil Killing by Staphylococcus aureus

    PubMed Central

    McGuinness, Will A.; Kobayashi, Scott D.; DeLeo, Frank R.

    2016-01-01

    Staphylococcus aureus causes many types of infections, ranging from self-resolving skin infections to severe or fatal pneumonia. Human innate immune cells, called polymorphonuclear leukocytes (PMNs or neutrophils), are essential for defense against S. aureus infections. Neutrophils are the most prominent cell type of the innate immune system and are capable of producing non-specific antimicrobial molecules that are effective at eliminating bacteria. Although significant progress has been made over the past few decades, our knowledge of S. aureus-host innate immune system interactions is incomplete. Most notably, S. aureus has the capacity to produce numerous molecules that are directed to protect the bacterium from neutrophils. Here we review in brief the role played by neutrophils in defense against S. aureus infection, and correspondingly, highlight selected S. aureus molecules that target key neutrophil functions. PMID:26999220

  15. Presence of Laminin Receptors in Staphylococcus aureus

    NASA Astrophysics Data System (ADS)

    Lopes, J. D.; Dos Reis, M.; Brentani, R. R.

    1985-07-01

    A characteristic feature of infection by Staphylococcus aureus is bloodstream invasion and widespread metastatic abscess formation. The ability to extravasate, which entails crossing the vascular basement membrane, appears to be critical for the organism's pathogenicity. Extravasation by normal and neoplastic mammalian cells has been correlated with the presence of specific cell surface receptors for the basement membrane glycoprotein laminin. Similar laminin receptors were found in Staphylococcus aureus but not in Staphylococcus epidermidis, a noninvasive pathogen. There were about 100 binding sites per cell, with an apparent binding affinity of 2.9 nanomolar. The molecular weight of the receptor was 50,000 and pI was 4.2. Eukaryotic laminin receptors were visualized by means of the binding of S. aureus in the presence of laminin. Prokaryotic and eukaryotic invasive cells might utilize similar, if not identical, mechanisms for invasion.

  16. Triclosan promotes Staphylococcus aureus nasal colonization.

    PubMed

    Syed, Adnan K; Ghosh, Sudeshna; Love, Nancy G; Boles, Blaise R

    2014-04-08

    The biocide triclosan is used in many personal care products, including toothpastes, soaps, clothing, and medical equipment. Consequently, it is present as a contaminant in the environment and has been detected in some human fluids, including serum, urine, and milk. Staphylococcus aureus is an opportunistic pathogen that colonizes the noses and throats of approximately 30% of the population. Colonization with S. aureus is known to be a risk factor for several types of infection. Here we demonstrate that triclosan is commonly found in the nasal secretions of healthy adults and the presence of triclosan trends positively with nasal colonization by S. aureus. We demonstrate that triclosan can promote the binding of S. aureus to host proteins such as collagen, fibronectin, and keratin, as well as inanimate surfaces such as plastic and glass. Lastly, triclosan-exposed rats are more susceptible to nasal colonization with S. aureus. These data reveal a novel factor that influences the ability of S. aureus to bind surfaces and alters S. aureus nasal colonization. IMPORTANCE Triclosan has been used as a biocide for over 40 years, but the broader effects that it has on the human microbiome have not been investigated. We demonstrate that triclosan is present in nasal secretions of a large portion of a test population and its presence correlates with Staphylococcus aureus nasal colonization. Triclosan also promotes the binding of S. aureus to human proteins and increases the susceptibility of rats to nasal colonization by S. aureus. These findings are significant because S. aureus colonization is a known risk factor for the development of several types of infections. Our data demonstrate the unintended consequences of unregulated triclosan use and contribute to the growing body of research demonstrating inadvertent effects of triclosan on the environment and human health.

  17. Mouse model of Staphylococcus aureus skin infection.

    PubMed

    Malachowa, Natalia; Kobayashi, Scott D; Braughton, Kevin R; DeLeo, Frank R

    2013-01-01

    Bacterial skin and soft tissue infections are abundant worldwide and many are caused by Staphylococcus aureus. Indeed, S. aureus is the leading cause of skin and soft tissue infections in the USA. Here, we describe a mouse model of skin and soft tissue infection induced by subcutaneous inoculation of S. aureus. This animal model can be used to investigate a number of factors related to the pathogenesis of skin and soft tissue infections, including strain virulence and the contribution of specific bacterial molecules to disease, and it can be employed to test the potential effectiveness of antibiotic therapies or vaccine candidates.

  18. Neutrophil-Mediated Phagocytosis of Staphylococcus aureus

    PubMed Central

    van Kessel, Kok P. M.; Bestebroer, Jovanka; van Strijp, Jos A. G.

    2014-01-01

    Initial elimination of invading Staphylococcus aureus from the body is mediated by professional phagocytes. The neutrophil is the major phagocyte of the innate immunity and plays a key role in the host defense against staphylococcal infections. Opsonization of the bacteria with immunoglobulins and complement factors enables efficient recognition by the neutrophil that subsequently leads to intracellular compartmentalization and killing. Here, we provide a review of the key processes evolved in neutrophil-mediated phagocytosis of S. aureus and briefly describe killing. As S. aureus is not helpless against the professional phagocytes, we will also highlight its immune evasion arsenal related to phagocytosis. PMID:25309547

  19. The T Cell Response to Staphylococcus aureus

    PubMed Central

    Bröker, Barbara M.; Mrochen, Daniel; Péton, Vincent

    2016-01-01

    Staphylococcus aureus (S. aureus) is a dangerous pathogen and a leading cause of both nosocomial and community acquired bacterial infection worldwide. However, on the other hand, we are all exposed to this bacterium, often within the first hours of life, and usually manage to establish equilibrium and coexist with it. What does the adaptive immune system contribute toward lifelong control of S. aureus? Will it become possible to raise or enhance protective immune memory by vaccination? While in the past the S. aureus-specific antibody response has dominated this discussion, the research community is now coming to appreciate the role that the cellular arm of adaptive immunity, the T cells, plays. There are numerous T cell subsets, each with differing functions, which together have the ability to orchestrate the immune response to S. aureus and hence to tip the balance between protection and pathology. This review summarizes the state of the art in this dynamic field of research. PMID:26999219

  20. Hemoglobin Promotes Staphylococcus aureus Nasal Colonization

    PubMed Central

    Schwartz, Kelly; Hernandez, Margarita; Boles, Blaise R.

    2011-01-01

    Staphylococcus aureus nasal colonization is an important risk factor for community and nosocomial infection. Despite the importance of S. aureus to human health, molecular mechanisms and host factors influencing nasal colonization are not well understood. To identify host factors contributing to nasal colonization, we collected human nasal secretions and analyzed their ability to promote S. aureus surface colonization. Some individuals produced secretions possessing the ability to significantly promote S. aureus surface colonization. Nasal secretions pretreated with protease no longer promoted S. aureus surface colonization, suggesting the involvement of protein factors. The major protein components of secretions were identified and subsequent analysis revealed that hemoglobin possessed the ability to promote S. aureus surface colonization. Immunoprecipitation of hemoglobin from nasal secretions resulted in reduced S. aureus surface colonization. Furthermore, exogenously added hemoglobin significantly decreased the inoculum necessary for nasal colonization in a rodent model. Finally, we found that hemoglobin prevented expression of the agr quorum sensing system and that aberrant constitutive expression of the agr effector molecule, RNAIII, resulted in reduced nasal colonization of S. aureus. Collectively our results suggest that the presence of hemoglobin in nasal secretions contributes to S. aureus nasal colonization. PMID:21750673

  1. An Improved Medium for Growing Staphylococcus aureus Biofilm

    DTIC Science & Technology

    2012-04-19

    Note An improved medium for growing Staphylococcus aureus biofilm Ping Chen, Johnathan J. Abercrombie, Nicole R. Jeffrey, Kai P. Leung ⁎ Microbiology...Keywords: Staphylococcus aureus Biofilm Human plasma Microfluidic A medium (Brain Heart Infusion plus 10% human plasma) was developed, tested, and...validated for growing Staphylococcus aureus biofilm in vitro. With this medium, S. aureus forms reproducible and robust biofilms in flow chambers under

  2. Repression of Staphylococcus aureus by Food Bacteria

    PubMed Central

    Troller, John A.; Frazier, W. C.

    1963-01-01

    The effects of environmental factors on the inhibition of an enterotoxin-producing strain of Staphylococcus aureus by food bacteria were investigated. Type of medium and temperature of incubation were important factors in determining the amount of inhibition. The pH range of maximal inhibition was found to be 7.4 to 6.2. Availability of oxygen was not a factor. As the ratios of inhibitor to staphylococcus were increased from 1:1 to 10:1 and 100:1, the amount of inhibition was markedly increased. Inhibition occurred in custard, where it increased with increasing ratios of effector to staphylococcus. The repression of the staphylococcus in all media usually was sufficient to be of practical significance. PMID:13994250

  3. Triclosan Promotes Staphylococcus aureus Nasal Colonization

    PubMed Central

    Syed, Adnan K.; Ghosh, Sudeshna; Love, Nancy G.; Boles, Blaise R.

    2014-01-01

    ABSTRACT The biocide triclosan is used in many personal care products, including toothpastes, soaps, clothing, and medical equipment. Consequently, it is present as a contaminant in the environment and has been detected in some human fluids, including serum, urine, and milk. Staphylococcus aureus is an opportunistic pathogen that colonizes the noses and throats of approximately 30% of the population. Colonization with S. aureus is known to be a risk factor for several types of infection. Here we demonstrate that triclosan is commonly found in the nasal secretions of healthy adults and the presence of triclosan trends positively with nasal colonization by S. aureus. We demonstrate that triclosan can promote the binding of S. aureus to host proteins such as collagen, fibronectin, and keratin, as well as inanimate surfaces such as plastic and glass. Lastly, triclosan-exposed rats are more susceptible to nasal colonization with S. aureus. These data reveal a novel factor that influences the ability of S. aureus to bind surfaces and alters S. aureus nasal colonization. PMID:24713325

  4. Genomic Analysis of Companion Rabbit Staphylococcus aureus

    PubMed Central

    Holmes, Mark A.; Harrison, Ewan M.; Fisher, Elizabeth A.; Graham, Elizabeth M.; Parkhill, Julian; Foster, Geoffrey; Paterson, Gavin K.

    2016-01-01

    In addition to being an important human pathogen, Staphylococcus aureus is able to cause a variety of infections in numerous other host species. While the S. aureus strains causing infection in several of these hosts have been well characterised, this is not the case for companion rabbits (Oryctolagus cuniculus), where little data are available on S. aureus strains from this host. To address this deficiency we have performed antimicrobial susceptibility testing and genome sequencing on a collection of S. aureus isolates from companion rabbits. The findings show a diverse S. aureus population is able to cause infection in this host, and while antimicrobial resistance was uncommon, the isolates possess a range of known and putative virulence factors consistent with a diverse clinical presentation in companion rabbits including severe abscesses. We additionally show that companion rabbit isolates carry polymorphisms within dltB as described as underlying host-adaption of S. aureus to farmed rabbits. The availability of S. aureus genome sequences from companion rabbits provides an important aid to understanding the pathogenesis of disease in this host and in the clinical management and surveillance of these infections. PMID:26963381

  5. Epidemiology of Staphylococcus aureus during space flight

    NASA Technical Reports Server (NTRS)

    Pierson, D. L.; Chidambaram, M.; Heath, J. D.; Mallary, L.; Mishra, S. K.; Sharma, B.; Weinstock, G. M.

    1996-01-01

    Staphylococcus aureus was isolated over 2 years from Space Shuttle mission crewmembers to determine dissemination and retention of bacteria. Samples before and after each mission were from nasal, throat, urine, and feces and from air and surface sampling of the Space Shuttle. DNA fingerprinting of samples by digestion of DNA with SmaI restriction endonuclease followed by pulsed-field gel electrophoresis showed S. aureus from each crewmember had a unique fingerprint and usually only one strain was carried by an individual. There was only one instance of transfer between crewmembers. Strains from interior surfaces after flight matched those of crewmembers, suggesting microbial fingerprinting may have forensic application.

  6. Epidemiology of Staphylococcus aureus during space flight.

    PubMed

    Pierson, D L; Chidambaram, M; Heath, J D; Mallary, L; Mishra, S K; Sharma, B; Weinstock, G M

    1996-12-31

    Staphylococcus aureus was isolated over 2 years from Space Shuttle mission crewmembers to determine dissemination and retention of bacteria. Samples before and after each mission were from nasal, throat, urine, and feces and from air and surface sampling of the Space Shuttle. DNA fingerprinting of samples by digestion of DNA with SmaI restriction endonuclease followed by pulsed-field gel electrophoresis showed S. aureus from each crewmember had a unique fingerprint and usually only one strain was carried by an individual. There was only one instance of transfer between crewmembers. Strains from interior surfaces after flight matched those of crewmembers, suggesting microbial fingerprinting may have forensic application.

  7. BACTERICIDAL SUBSTANCE FROM STAPHYLOCOCCUS AUREUS

    PubMed Central

    Dajani, Adnan S.; Gray, Ernest D.; Wannamaker, Lewis W.

    1970-01-01

    A bactericidal substance previously isolated from phage type 71 Slaphylococcus aureus has been further identified and characterized. Staphylococci belonging to phage type 71 produce the substance in higher titers than staphylococci lysed by other phages in group II in addition to phage 71. Other staphylococci do not produce the bactericidal substance. The bactericidal substance shares several of the properties of bacteriocins but differs from this group of antibiotic substances in some respects. A combination of ammonium sulfate fractionation and gel filtration on a Sephadex G-100 column resulted in considerable degree of purification of the bactericidal substance. The substance is a previously unrecognized product of S. aureus and is distinct from other extracellular products of this organism. PMID:5443199

  8. [Screening for Staphylococcus aureus before heart surgery].

    PubMed

    Bandiera-Clerc, Catherine; Le Godais, Sandrine; Vala, Dominique

    2017-02-01

    One patient out of four having to undergo an operation is a carrier of Staphylococcus aureus. This, notably in cases of heart surgery, increases the risk of developing a nosocomial infection with this very germ in the post-operative period. Nurses must implement appropriate care procedures to favour decolonisation and the education of these patients. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. [Change in drug resistance of Staphylococcus aureus].

    PubMed

    Lin, Yan; Liu, Yan; Luo, Yan-Ping; Liu, Chang-Ting

    2013-11-01

    To analyze the change in drug resistance of Staphylococcus aureus (SAU) in the PLA general hospital from January 2008 to December 2012, and to provide solid evidence to support the rational use of antibiotics for clinical applications. The SAU strains isolated from clinical samples in the hospital were collected and subjected to the Kirby-Bauer disk diffusion test. The results were assessed based on the 2002 American National Committee for Clinical Laboratory Standards (NCCLS) guidelines. SAU strains were mainly isolated from sputum, urine, blood and wound excreta and distributed in penology, neurology wards, orthopedics and surgery ICU wards. Except for glycopeptide drugs, methicillin-resistant Staphylococcus aureus (MRSA) had a higher drug resistance rate than those of the other drugs and had significantly more resistance than methicillin-sensitive Staphylococcus aureus (MSSA) (P < 0.05). In the dynamic observation of drug resistance, we discovered a gradual increase in drug resistance to fourteen test drugs during the last five years. Drug resistance rate of SAU stayed at a higher level over the last five years; moreover, the detection ratio of MRSA keeps rising year by year. It is crucial for physicians to use antibiotics rationally and monitor the change in drug resistance in a dynamic way.

  10. Pathogenesis of Staphylococcus aureus Bloodstream Infections

    PubMed Central

    Thomer, Lena; Schneewind, Olaf; Missiakas, Dominique

    2016-01-01

    Staphylococcus aureus , a Gram-positive bacterium colonizing nares, skin, and the gastrointestinal tract, frequently invades the skin, soft tissues, and bloodstreams of humans. Even with surgical and antibiotic therapy, bloodstream infections are associated with significant mortality. The secretion of coagulases, proteins that associate with and activate the host hemostatic factor prothrombin, and the bacterial surface display of agglutinins, proteins that bind polymerized fibrin, are key virulence strategies for the pathogenesis of S. aureus bloodstream infections, which culminate in the establishment of abscess lesions. Pathogen-controlled processes, involving a wide spectrum of secreted factors, are responsible for the recruitment and destruction of immune cells, transforming abscess lesions into purulent exudate, with which staphylococci disseminate to produce new infectious lesions or to infect new hosts. Research on S. aureus bloodstream infections is a frontier for the characterization of protective vaccine antigens and the development of immune therapeutics aiming to prevent disease or improve outcomes. PMID:26925499

  11. The Staphylococcus aureus “superbug”

    PubMed Central

    Foster, Timothy J.

    2004-01-01

    There has been some debate about the disease-invoking potential of Staphylococcus aureus strains and whether invasive disease is associated with particularly virulent genotypes, or “superbugs.” A study in this issue of the JCI describes the genotyping of a large collection of nonclinical, commensal S. aureus strains from healthy individuals in a Dutch population. Extensive study of their genetic relatedness by amplified restriction fragment typing and comparison with strains that are associated with different types of infections revealed that the S. aureus population is clonal and that some strains have enhanced virulence. This is discussed in the context of growing interest in the mechanisms of bacterial colonization, antibiotic resistance, and novel vaccines. PMID:15599392

  12. TOLERANCE OF STAPHYLOCOCCUS AUREUS TO SODIUM CHLORIDE

    PubMed Central

    Parfentjev, I. A.; Catelli, Anna R.

    1964-01-01

    Parfentjev, I. A. (Institute of Applied Biology, New York, N.Y.), and Anna R. Catelli. Tolerance of Staphylococcus aureus to sodium chloride. J. Bacteriol. 88:1–3. 1964.—The tolerance of Staphylococcus aureus to high concentrations of sodium chloride in liquid medium has been reported. We found that S. aureus grows at 37 C in Tryptose Phosphate Broth saturated with sodium chloride. No difference was noticed between possibly pathogenic and nonpathogenic strains. Under the conditions of our tests, no changes in the original properties of S. aureus strains occurred. In contrast, solutions of sodium chloride in distilled water were injurious to staphylococci and killed most of these organisms in 1 hr. Staphylococci were killed faster at 37 C than at room temperature in a solution of 0.85% sodium chloride in water. Addition of traces of Tryptose Phosphate Broth had a protective effect and prolonged the life of these organisms in physiological saline. All tests were performed at pH 7.2. PMID:14197887

  13. Immunopathological features of rat Staphylococcus aureus arthritis.

    PubMed Central

    Bremell, T; Lange, S; Holmdahl, R; Rydén, C; Hansson, G K; Tarkowski, A

    1994-01-01

    Staphylococcus aureus is the most common bacterial species found in nongonococcal bacterial arthritis in humans. We present the first description, to our knowledge, of an outbreak of spontaneous staphylococcal arthritis in a rat colony. In a group of 10 rats, 9 displayed arthritis. Clinically, the most obvious findings were arthritis of one or both hindpaws and malaise. Bacteriophage typing showed the common phage type 85 in isolates recovered from the joints, blood, and bedding of rats and from the nose and cheeks of one person from the staff of the animal facility. The S. aureus strain proved to produce staphylococcal enterotoxin A and exhibited strong binding to collagen types I and II and bone sialoprotein, which are potentially important virulence factors. When the recovered S. aureus strain was injected intravenously into healthy rats, severe septic arthritis was induced in almost all of the animals. The arthritic lesions were characterized by infiltration of phagocytic cells and T lymphocytes into the synovium. Many of the synovial cells strongly expressed major histocompatibility complex class II molecules. Increased levels of interleukin 6 in serum as well as a prominent polyclonal B-cell activation were noted throughout the disease course. Pretreatment of S. aureus-injected rats in vivo with an antibody to the alpha beta T-cell receptor significantly decreased the severity of the arthritis. Our results indicate that alpha beta + T lymphocytes contribute to an erosive and persistent course of S. aureus arthritis. Images PMID:8188356

  14. Staphylococcus aureus dispersal from healthy volunteers.

    PubMed

    Thompson, Katy-Anne; Copley, Vicky R; Parks, Simon; Walker, James T; Bennett, Allan M

    2014-03-01

    Understanding Staphylococcus aureus dispersal from human carriers is vital for preventing transmission and colonization of this organism in health care settings. This study investigated the S aureus supershedder hypothesis in relation to attributes of healthy volunteers. Microbial aerosol generation from volunteers was quantified within a controlled environmental chamber during walking or sitting activities. Biological air samplers were used to determine numbers of total S aureus colony-forming units disseminated during these activities. A total of 17 volunteers was sampled on 3 occasions. Hairstyle (long hair tied up or a shaved head) was the only significant predictor of dissemination of S aureus (5% significance level). No other significant effects were found at the 5% level. A negative binomial distribution provides the best fit with respect to S aureus. We found that, in the context of our small sample size, hairstyle (long hair tied up or a shaved head) statistically affected levels of bacteria shed from volunteers. However, we found no evidence for "supershedders" or "cloud adults," suggesting they are at an extreme end of a continuous distribution. Crown Copyright © 2014. Published by Mosby, Inc. All rights reserved.

  15. [Staphylococcus aureus broncho-pulmonary infections].

    PubMed

    Valour, F; Chebib, N; Gillet, Y; Reix, P; Laurent, F; Chidiac, C; Ferry, T

    2013-12-01

    Staphylococcus aureus accounts for 2-5% of the etiologies of community-acquired pneumonia. These infections occur mainly in elderly patients with comorbidity, after a respiratory viral infection. S. aureus could also be responsible for necrotizing pneumonia, which occurs in young subjects, also after flu. Necrotizing pneumonia are associated with the production of a particular staphylococcal toxin called Panton-Valentine leukocidin, responsible for pulmonary focal necrosis, occurrence haemoptysis, leucopenia, and death. In Europe, these strains are still predominantly sensitive to anti-staphylococcal penicillin, which must be used at high dosage intravenously in combination with an antibiotic that reduces toxin production such as clindamycin, and intravenous immunoglobulin in severe cases. The mortality rate is estimated at 50%. In addition, S. aureus is one of the pathogens involved in early respiratory infections in cystic fibrosis patients, in whom methicillin resistance plays an important prognostic role. However, the involvement of S. aureus in COPD exacerbations is rare. Finally, S. aureus represents 20 to 30% of cases of hospital-acquired pneumonia, including ventilator-associated pneumonia. In these cases, methicillin-resistance is common and requires the use of glycopeptides or linezolid. The place of new anti-staphylococcal antibiotics such as new generation cephalosporins or tigecyclin remains to be defined.

  16. Potassium Uptake Modulates Staphylococcus aureus Metabolism

    PubMed Central

    Gries, Casey M.; Sadykov, Marat R.; Bulock, Logan L.; Chaudhari, Sujata S.; Thomas, Vinai C.; Bose, Jeffrey L.

    2016-01-01

    ABSTRACT As a leading cause of community-associated and nosocomial infections, Staphylococcus aureus requires sophisticated mechanisms that function to maintain cellular homeostasis in response to its exposure to changing environmental conditions. The adaptation to stress and maintenance of homeostasis depend largely on membrane activity, including supporting electrochemical gradients and synthesis of ATP. This is largely achieved through potassium (K+) transport, which plays an essential role in maintaining chemiosmotic homeostasis, affects antimicrobial resistance, and contributes to fitness in vivo. Here, we report that S. aureus Ktr-mediated K+ uptake is necessary for maintaining cytoplasmic pH and the establishment of a proton motive force. Metabolite analyses revealed that K+ deficiency affects both metabolic and energy states of S. aureus by impairing oxidative phosphorylation and directing carbon flux toward substrate-level phosphorylation. Taken together, these results underline the importance of K+ uptake in maintaining essential components of S. aureus metabolism. IMPORTANCE Previous studies describing mechanisms for K+ uptake in S. aureus revealed that the Ktr-mediated K+ transport system was required for normal growth under alkaline conditions but not under neutral or acidic conditions. This work focuses on the effect of K+ uptake on S. aureus metabolism, including intracellular pH and carbon flux, and is the first to utilize a pH-dependent green fluorescent protein (GFP) to measure S. aureus cytoplasmic pH. These studies highlight the role of K+ uptake in supporting proton efflux under alkaline conditions and uncover a critical role for K+ uptake in establishing efficient carbon utilization. PMID:27340697

  17. Staphylococcus aureus exhibit similarities in their interactions with Acanthamoeba and ThP1 macrophage-like cells.

    PubMed

    Cardas, Mihaela; Khan, Naveed Ahmed; Alsam, Selwa

    2012-12-01

    Staphylococcus aureus is a leading cause of nosocomial infections. Haematogenous spread is a pre-requisite but it is not clear how S. aureus survive the onslaught of macrophages. Acanthamoeba is a protozoan pathogen that is remarkably similar to macrophages, particularly in their cellular structure (morphological and ultra-structural features), molecular motility, biochemical physiology, ability to capture prey by phagocytosis and interactions with microbial pathogens. Thus, we hypothesize that S. aureus exhibit similarities in their interactions with Acanthamoeba and ThP1 macrophage-like cells. Here, we studied interactions of methicillin-sensitive S. aureus (MSSA), methicillin-resistant S. aureus (MRSA) and Staphylococcus epidermidis (SE) with Acanthamoeba castellanii belonging to the T4 genotype and macrophage-like cells (ThP1). The findings revealed that both MRSA and MSSA exhibited similarities in their binding/association and invasion of A. castellanii and ThP1 cells. Long-term incubation showed that MRSA and MSSA can survive intracellularly of both Acanthamoeba and ThP1 cells. Overall, these findings suggest that Acanthamoeba exhibit similar characteristics with ThP1 macrophage-like cells in their interaction with MRSA and MSSA. Additionally it was shown that bacteria survive inside Acanthamoeba during the encystment process as evidenced by bacterial recovery from mature cysts. Given that Acanthamoeba cysts are airborne, these findings suggest that cysts may act as "Trojan horse" to help spread MRSA to susceptible hosts.

  18. Hyaluronan Modulation Impacts Staphylococcus aureus Biofilm Infection

    PubMed Central

    Ibberson, Carolyn B.; Parlet, Corey P.; Kwiecinski, Jakub; Crosby, Heidi A.; Meyerholz, David K.

    2016-01-01

    Staphylococcus aureus is a leading cause of chronic biofilm infections. Hyaluronic acid (HA) is a large glycosaminoglycan abundant in mammalian tissues that has been shown to enhance biofilm formation in multiple Gram-positive pathogens. We observed that HA accumulated in an S. aureus biofilm infection using a murine implant-associated infection model and that HA levels increased in a mutant strain lacking hyaluronidase (HysA). S. aureus secretes HysA in order to cleave HA during infection. Through in vitro biofilm studies with HA, the hysA mutant was found to accumulate increased biofilm biomass compared to the wild type, and confocal microscopy showed that HA is incorporated into the biofilm matrix. Exogenous addition of purified HysA enzyme dispersed HA-containing biofilms, while catalytically inactive enzyme had no impact. Additionally, induction of hysA expression prevented biofilm formation and also dispersed an established biofilm in the presence of HA. These observations were corroborated in the implant model, where there was decreased dissemination from an hysA mutant biofilm infection compared to the S. aureus wild type. Histopathology demonstrated that infection with an hysA mutant caused significantly reduced distribution of tissue inflammation compared to wild-type infection. To extend these studies, the impact of HA and S. aureus HysA on biofilm-like aggregates found in joint infections was examined. We found that HA contributes to the formation of synovial fluid aggregates, and HysA can disrupt aggregate formation. Taken together, these studies demonstrate that HA is a relevant component of the S. aureus biofilm matrix and HysA is important for dissemination from a biofilm infection. PMID:27068096

  19. Pseudomonas aeruginosa, Staphylococcus aureus, and fluoroquinolone use.

    PubMed

    MacDougall, Conan; Harpe, Spencer E; Powell, J Patrick; Johnson, Christopher K; Edmond, Michael B; Polk, Ron E

    2005-08-01

    Few long-term multicenter investigations have evaluated the relationships between aggregate antimicrobial drug use in hospitals and bacterial resistance. We measured fluoroquinolone use from 1999 through 2003 in a network of US hospitals. The percentages of fluoroquinolone-resistant Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) were obtained from yearly antibiograms at each hospital. Univariate linear regression showed significant associations between a hospital's volume of fluoroquinolone use and percent resistance in most individual study years (1999-2001 for P. aeruginosa, 1999-2002 for S. aureus). When the method of generalized estimating equations was used, a population-averaged longitudinal model incorporating total fluoroquinolone use and the previous year's resistance (to account for autocorrelation) did not show a significant effect of fluoroquinolone use on percent resistance for most drug-organism combinations, except for the relationship between levofloxacin use and percent MRSA. The ecologic relationship between fluoroquinolone use and resistance is complex and requires further study.

  20. [Antibiotic stewardship and Staphylococcus aureus Bacteremia].

    PubMed

    Weis, S; Kimmig, A; Hagel, S; Pletz, M W

    2017-04-04

    Rates of antibiotic resistance are increasing worldwide and impact on the treatment of patients with bacterial infections. A broad and uncritical application in inpatient and outpatient settings as well as in agriculture has been recognized as the main driving force. Antibiotic stewardship (ABS) programs aim at countering this worrisome development using various direct interventions such as infectious disease counseling. Blood stream infections caused by Staphylococcus (S.) aureus are severe infections associated with high mortality rates. ABS interventions such as de-eskalation of the antibiotic regimen or application of narrow-spectrum beta-lactam antibiotics can significantly reduce mortality rates. In this review, we discuss the importance of ABS programs and infectious disease counseling for the treatment of S. aureus blood stream infection.

  1. Methicillin-resistant Staphylococcus aureus: the superbug.

    PubMed

    Ippolito, Giuseppe; Leone, Sebastiano; Lauria, Francesco N; Nicastri, Emanuele; Wenzel, Richard P

    2010-10-01

    Over the last decade, methicillin-resistant Staphylococcus aureus (MRSA) strains have emerged as serious pathogens in the nosocomial and community setting. Hospitalization costs associated with MRSA infections are substantially greater than those associated with methicillin-sensitive S. aureus (MSSA) infections, and MRSA has wider economic effects that involve indirect costs to the patient and to society. In addition, there is some evidence suggesting that MRSA infections increase morbidity and the risk of mortality. Glycopeptides are the backbone antibiotics for the treatment of MRSA infections. However, several recent reports have highlighted the limitations of vancomycin, and its role in the management of serious infections is now being reconsidered. Several new antimicrobials demonstrate in vitro activity against MRSA and other Gram-positive bacteria. Data from large surveys indicate that linezolid, daptomycin, and tigecycline are almost universally active against MRSA. This review will briefly discuss the epidemiology, costs, outcome, and therapeutic options for the management of MRSA infections.

  2. Mechanisms of antibiotic resistance in Staphylococcus aureus.

    PubMed

    Pantosti, Annalisa; Sanchini, Andrea; Monaco, Monica

    2007-06-01

    Staphylococcus aureus can exemplify better than any other human pathogen the adaptive evolution of bacteria in the antibiotic era, as it has demonstrated a unique ability to quickly respond to each new antibiotic with the development of a resistance mechanism, starting with penicillin and methicillin, until the most recent, linezolid and daptomycin. Resistance mechanisms include enzymatic inactivation of the antibiotic (penicillinase and aminoglycoside-modification enzymes), alteration of the target with decreased affinity for the antibiotic (notable examples being penicillin-binding protein 2a of methicillin-resistant S. aureus and D-Ala-D-Lac of peptidoglycan precursors of vancomycin-resistant strains), trapping of the antibiotic (for vancomycin and possibly daptomycin) and efflux pumps (fluoroquinolones and tetracycline). Complex genetic arrays (staphylococcal chromosomal cassette mec elements or the vanA operon) have been acquired by S. aureus through horizontal gene transfer, while resistance to other antibiotics, including some of the most recent ones (e.g., fluoroquinolones, linezolid and daptomycin) have developed through spontaneous mutations and positive selection. Detection of the resistance mechanisms and their genetic basis is an important support to antibiotic susceptibility surveillance in S. aureus.

  3. Staphylococcus aureus vaccines: Deviating from the carol

    PubMed Central

    2016-01-01

    Staphylococcus aureus, a commensal of the human nasopharynx and skin, also causes invasive disease, most frequently skin and soft tissue infections. Invasive disease caused by drug-resistant strains, designated MRSA (methicillin-resistant S. aureus), is associated with failure of antibiotic therapy and elevated mortality. Here we review polysaccharide-conjugate and subunit vaccines that were designed to prevent S. aureus infection in patients at risk of bacteremia or surgical wound infection but failed to reach their clinical endpoints. We also discuss vaccines with ongoing trials for combinations of polysaccharide-conjugates and subunits. S. aureus colonization and invasive disease are not associated with the development of protective immune responses, which is attributable to a large spectrum of immune evasion factors. Two evasive strategies, assembly of protective fibrin shields via coagulases and protein A–mediated B cell superantigen activity, are discussed as possible vaccine targets. Although correlates for protective immunity are not yet known, opsonophagocytic killing of staphylococci by phagocytic cells offers opportunities to establish such criteria. PMID:27526714

  4. Methicillin-resistant Staphylococcus aureus in obstetrics.

    PubMed

    Sheffield, Jeanne S

    2013-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the major multiple antibiotic-resistant bacterial pathogens causing serious community-associated and health care-associated infections. It is now pervasive in the obstetric population associated with skin and soft tissue infections, mastitis, episiotomy, and cesarean wound infections and urinary tract infections. This review addresses the epidemiology, definitions, microbiology, and pathogenesis as well as common clinical presentations. A discussion of the 2011 Infectious Diseases Society of America MRSA treatment guidelines details available antibiotics, invasive and noninvasive MRSA management, and specific factors related to obstetrics. Finally, prevention strategies including decolonization are discussed. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Prevalence of Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA) in the oral cavity.

    PubMed

    Koukos, Georgios; Sakellari, Dimitra; Arsenakis, Minas; Tsalikis, Lazaros; Slini, Theodora; Konstantinidis, Antonios

    2015-09-01

    To assess the prevalence of Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA) in plaque and tongue samples from systemically healthy subjects with periodontal health, gingivitis or chronic periodontitis. After screening 720 potentially eligible subjects, 154 systemically healthy participants were ultimately enrolled in the current study. Subgingival samples were taken from the first molars and the tongue and analyzed for the presence of S. aureus and MRSA by polymerase chain reaction (PCR), using primers and conditions previously described in the literature. In addition, samples were taken from deep periodontal pockets of chronic periodontitis patients. Statistical analysis was performed by applying non-parametric tests (Kruskal-Wallis for clinical parameters, and z-test with Bonferroni corrections for distributions of assessed parameters). All comparisons were set at the 0.05 significance level. S. aureus was detected in 18% of all participants and in 10% of the samples tested. No significant differences were found in its distribution among the three investigated groups (z-test for proportions with Bonferroni corrections, p>0.05). The mecA gene was not present in any of the S. aureus found. S. aureus can be found in the oral environment regardless of the periodontal conditions and therefore should be considered as a member of the transient flora not participating in periodontal pathology. Subgingival sites and tongue surfaces seem to be an unusual habitat of MRSA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Susceptibilities of Escherichia coli and Staphylococcus aureus to Aloe barbadensis.

    PubMed

    Shilpakala, S R; Prathiba, J; Malathi, R

    2009-01-01

    The in vitro susceptibilities of Escherichia coli and Staphylococcus aureus were evaluated and the two organisms were susceptible to the inner gel of aloe barbadensis, though it was more effective against Staphylococcus aureus than Escherichia coli. The reduction for Aloe Vera (AV) needed to suppress the growth of the gram-positive bacterium was attributed to the structural differences between the two organisms.

  7. [Staphylococcus aureus prevalence among preschool- and school-aged pupils].

    PubMed

    Pavilonyte, Zaneta; Kacerauskiene, Justina; Budryte, Brigita; Keizeris, Tadas; Junevicius, Jonas; Pavilonis, Alvydas

    2007-01-01

    To determine the prevalence and incidence of Staphylococcus aureus strains among preschool- and school-aged pupils and susceptibility of these strains to antimicrobial materials. A study of 243 preschool- and 300 school-aged pupils was conducted during 2003-2004. Identification of Staphylococcus aureus was made with plasmacoagulase and DNase tests. The resistance of Staphylococcus aureus to antibiotics, beta-lactamase activity, phagotypes, and phage groups were determined. The isolated Staphylococcus aureus strains were tested for resistance to methicillin by performing disc diffusion method using commercial discs (Oxoid) (methicillin 5 microg per disk and oxacillin 1 microg per disk). A total of 292 (53.8%) Staphylococcus aureus strains were isolated and identified (113 (46.5%) from preschool- and 179 (59.7%) from school-aged pupils). The prevalence of Staphylococcus aureus strains among preschool-aged pupils varied from 46.5% to 47%. It increased to 59.0% (P>0.05) among schoolchildren aged from 11 to 15 years and to 73.0% (P<0.001) among schoolchildren aged from 16 to 19 years. Six methicillin-resistant Staphylococcus aureus strains were isolated: two (1.8%) of them were from preschool-aged and four (2.2%) from school-aged pupils. The prevalence of Staphylococcus aureus strains with beta-lactamase activity increased from 70.7 to 76.6% in preschool-aged pupils, and it varied from 72.0 to 79.0% in school-aged pupils (P>0.05). Staphylococcus aureus strains of phage group II (32.2-43.4%) were prevailing; nontypable Staphylococcus aureus strains made up 19.2-33.6%. The prevalence of Staphylococcus aureus among preschool-aged children is 41.7 to 48.8%, and it increases among 9th-12th-grade pupils (73.0%, P<0.001). Some Staphylococcus aureus strains (2.1%) were resistant to methicillin. Staphylococcus aureus strains of phage group II (39.0%, P<0.05) are most prevalent among preschool- and school-aged pupils. Pupils were colonized with methicillin

  8. [Staphylococcus aureus in food determined by polymerase chain reaction].

    PubMed

    Tian, Jing; Ji, Rong; Yang, Jun; Li, Yepeng

    2007-03-01

    To establish a rapid polymerase chain reaction (PCR)method for detection of staphylococcus aureus in milk, ice cream and meat. Two pairs of oligonucleotide primers were designed with thermo nuclease gene nuc and surfaced-associated fibrinogen-binding protein gene ClfA to detect staphylococcus aureus. Fifty-two staphylococcus aureus and thirty-one non staphylococcus aureus were amplified by PCR to verify the specificity. Various numbers of bacteria were added into milk, ice cream and meat. After enrichment, DNA extracted in different time was amplified by PCR to verify detection limit. Each primer pair allows specific detection. The limit of detection was 10 cfu/g (ml) in three kinds of food. Whole procedure of detection could be finished in 24 hours. A rapid, sensitive and specific PCR method can be applied detecting staphylococcus aureus in milk, ice cream and meat.

  9. Staphopains Modulate Staphylococcus aureus Biofilm Integrity

    PubMed Central

    Mootz, Joe M.; Malone, Cheryl L.; Shaw, Lindsey N.

    2013-01-01

    Staphylococcus aureus is a known cause of chronic biofilm infections that can reside on medical implants or host tissue. Recent studies have demonstrated an important role for proteinaceous material in the biofilm structure. The S. aureus genome encodes many secreted proteases, and there is growing evidence that these enzymes have self-cleavage properties that alter biofilm integrity. However, the specific contribution of each protease and mechanism of biofilm modulation is not clear. To address this issue, we utilized a sigma factor B (ΔsigB) mutant where protease activity results in a biofilm-negative phenotype, thereby creating a condition where the protease(s) responsible for the phenotype could be identified. Using a plasma-coated microtiter assay, biofilm formation was restored to the ΔsigB mutant through the addition of the cysteine protease inhibitor E-64 or by using Staphostatin inhibitors that specifically target the extracellular cysteine proteases SspB and ScpA (called Staphopains). Through construction of gene deletion mutants, we determined that an sspB scpA double mutant restored ΔsigB biofilm formation, and this recovery could be replicated in plasma-coated flow cell biofilms. Staphopain levels were also found to be decreased under biofilm-forming conditions, possibly allowing biofilm establishment. The treatment of S. aureus biofilms with purified SspB or ScpA enzyme inhibited their formation, and ScpA was also able to disperse an established biofilm. The antibiofilm properties of ScpA were conserved across S. aureus strain lineages. These findings suggest an underappreciated role of the SspB and ScpA cysteine proteases in modulating S. aureus biofilm architecture. PMID:23798534

  10. Survival of Staphylococcus aureus on fomites.

    PubMed

    Cuesta, Alicia; Nastri, Natalia; Bernat, Maria; Brusca, Maria; Turcot, Liliana; Nastri, Maria; Rosa, Alcira C

    2008-01-01

    The aim of this study was to evaluate duration of survival of Staphylococcus aureus on contaminated standardized fomites, such as sterilization paper (SP) and polyester previously sterilized in a steam autoclave, and to determine the potential inhibitory effects of the substrates (fabrics used to manufacture garments and special wrapping paper used in the dental setting) using the bacteriostasis test. The test was performed on two types of sterile standardized samples (T1 and T2). Sterility of the samples was validated following the protocol in use at the Department of Microbiology, after which the samples were inoculated with 50 microl of a calibrated suspension of Staphylococcus aureus (reference strain ATCC 25923) in the exponential growth phase, in a final concentration of 10(7) cfu/ml and 10(6) cfu/ml). The samples were incubated at 27 degrees C and survival and concentration of microorganisms attached to the surface of the substrates was determined at the following experimental time points: immediately post-contamination, and 3 hours, 24 hours, 3 days, and 7 days post-contamination. Recovery was determined and expressed as a percentage; the bacteriostasis test was performed and showed negative results. Our results suggest that the quantity of recovered microorganisms varies according to the type of substrate and that there is a relation between survival and incubation time of the inoculated substrate serving as an artificial niche.

  11. A novel in vitro model for haematogenous spreading of S. aureus device biofilms demonstrating clumping dispersal as an advantageous dissemination mechanism.

    PubMed

    Grønnemose, R B; Saederup, K L; Kolmos, H J; Hansen, S W K; Asferg, C A; Rasmussen, K J; Palarasah, Y; Andersen, T E

    2017-09-05

    Staphylococcus aureus is able to disseminate from vascular device biofilms to the blood and organs, resulting in life-threatening infections such as endocarditis. The mechanisms behind spreading are largely unknown, especially how the bacterium escapes immune effectors and antibiotics in the process. Using an in vitro catheter infection model, we studied S. aureus biofilm growth, late-stage dispersal, and reattachment to downstream endothelial cell layers. The ability of the released biofilm material to resist host response and disseminate in vivo was furthermore studied in whole blood and phagocyte survival assays and in a short-term murine infection model. We found that S. aureus biofilms formed in flow of human plasma release biofilm thromboemboli with embedded bacteria and bacteria-secreted polysaccharides. The emboli disseminate as antibiotic and immune resistant vehicles that hold the ability to adhere to and initiate colonisation of endothelial cell layers under flow. In vivo experiments showed that the released biofilm material reached the heart similarly as ordinary broth-grown bacteria but also that clumps to some extend were trapped in the lungs. The clumping dispersal of S. aureus from in vivo-like vascular biofilms and their specific properties demonstrated here help explain the pathophysiology associated with S. aureus bloodstream infections. © 2017 John Wiley & Sons Ltd.

  12. Complete Genome Sequence of Staphylococcus aureus Strain Wood 46

    PubMed Central

    Balachandran, Manasi; Riley, Matthew C.; Bemis, David A.

    2017-01-01

    ABSTRACT Here, we report the first complete genome sequence of the Staphylococcus aureus strain Wood 46. Wood 46 has played an important role in understanding the virulence and pathogenesis of S. aureus infections. This report will assist efforts in vaccine development against methicillin-resistant S. aureus (MRSA) infections. PMID:28360163

  13. Multidrug-Resistant Staphylococcus aureus in US Meat and Poultry

    PubMed Central

    Waters, Andrew E.; Contente-Cuomo, Tania; Buchhagen, Jordan; Liu, Cindy M.; Watson, Lindsey; Pearce, Kimberly; Foster, Jeffrey T.; Bowers, Jolene; Driebe, Elizabeth M.; Engelthaler, David M.; Keim, Paul S.

    2011-01-01

    We characterized the prevalence, antibiotic susceptibility profiles, and genotypes of Staphylococcus aureus among US meat and poultry samples (n = 136). S. aureus contaminated 47% of samples, and multidrug resistance was common among isolates (52%). S. aureus genotypes and resistance profiles differed significantly among sample types, suggesting food animal–specific contamination. PMID:21498385

  14. Methicillin-Susceptible, Vancomycin-Resistant Staphylococcus aureus, Brazil

    PubMed Central

    Panesso, Diana; Planet, Paul J.; Diaz, Lorena; Hugonnet, Jean-Emmanuel; Tran, Truc T.; Narechania, Apurva; Munita, Jose M.; Rincon, Sandra; Carvajal, Lina P.; Reyes, Jinnethe; Londoño, Alejandra; Smith, Hannah; Sebra, Robert; Deikus, Gintaras; Weinstock, George M.; Murray, Barbara E.; Rossi, Flavia; Arthur, Michel

    2015-01-01

    We report characterization of a methicillin-susceptible, vancomycin-resistant bloodstream isolate of Staphylococcus aureus recovered from a patient in Brazil. Emergence of vancomycin resistance in methicillin-susceptible S. aureus would indicate that this resistance trait might be poised to disseminate more rapidly among S. aureus and represents a major public health threat. PMID:26402569

  15. Methicillin-Susceptible, Vancomycin-Resistant Staphylococcus aureus, Brazil.

    PubMed

    Panesso, Diana; Planet, Paul J; Diaz, Lorena; Hugonnet, Jean-Emmanuel; Tran, Truc T; Narechania, Apurva; Munita, Jose M; Rincon, Sandra; Carvajal, Lina P; Reyes, Jinnethe; Londoño, Alejandra; Smith, Hannah; Sebra, Robert; Deikus, Gintaras; Weinstock, George M; Murray, Barbara E; Rossi, Flavia; Arthur, Michel; Arias, Cesar A

    2015-10-01

    We report characterization of a methicillin-susceptible, vancomycin-resistant bloodstream isolate of Staphylococcus aureus recovered from a patient in Brazil. Emergence of vancomycin resistance in methicillin-susceptible S. aureus would indicate that this resistance trait might be poised to disseminate more rapidly among S. aureus and represents a major public health threat.

  16. Complete Genome Sequence of Staphylococcus aureus Strain Wood 46.

    PubMed

    Balachandran, Manasi; Riley, Matthew C; Bemis, David A; Kania, Stephen A

    2017-03-30

    Here, we report the first complete genome sequence of the Staphylococcus aureus strain Wood 46. Wood 46 has played an important role in understanding the virulence and pathogenesis of S. aureus infections. This report will assist efforts in vaccine development against methicillin-resistant S. aureus (MRSA) infections.

  17. Toxin-Antitoxin Systems of Staphylococcus aureus

    PubMed Central

    Schuster, Christopher F.; Bertram, Ralph

    2016-01-01

    Toxin-antitoxin (TA) systems are small genetic elements found in the majority of prokaryotes. They encode toxin proteins that interfere with vital cellular functions and are counteracted by antitoxins. Dependent on the chemical nature of the antitoxins (protein or RNA) and how they control the activity of the toxin, TA systems are currently divided into six different types. Genes comprising the TA types I, II and III have been identified in Staphylococcus aureus. MazF, the toxin of the mazEF locus is a sequence-specific RNase that cleaves a number of transcripts, including those encoding pathogenicity factors. Two yefM-yoeB paralogs represent two independent, but auto-regulated TA systems that give rise to ribosome-dependent RNases. In addition, omega/epsilon/zeta constitutes a tripartite TA system that supposedly plays a role in the stabilization of resistance factors. The SprA1/SprA1AS and SprF1/SprG1 systems are post-transcriptionally regulated by RNA antitoxins and encode small membrane damaging proteins. TA systems controlled by interaction between toxin protein and antitoxin RNA have been identified in S. aureus in silico, but not yet experimentally proven. A closer inspection of possible links between TA systems and S. aureus pathophysiology will reveal, if these genetic loci may represent druggable targets. The modification of a staphylococcal TA toxin to a cyclopeptide antibiotic highlights the potential of TA systems as rather untapped sources of drug discovery. PMID:27164142

  18. Toxin-Antitoxin Systems of Staphylococcus aureus.

    PubMed

    Schuster, Christopher F; Bertram, Ralph

    2016-05-05

    Toxin-antitoxin (TA) systems are small genetic elements found in the majority of prokaryotes. They encode toxin proteins that interfere with vital cellular functions and are counteracted by antitoxins. Dependent on the chemical nature of the antitoxins (protein or RNA) and how they control the activity of the toxin, TA systems are currently divided into six different types. Genes comprising the TA types I, II and III have been identified in Staphylococcus aureus. MazF, the toxin of the mazEF locus is a sequence-specific RNase that cleaves a number of transcripts, including those encoding pathogenicity factors. Two yefM-yoeB paralogs represent two independent, but auto-regulated TA systems that give rise to ribosome-dependent RNases. In addition, omega/epsilon/zeta constitutes a tripartite TA system that supposedly plays a role in the stabilization of resistance factors. The SprA1/SprA1AS and SprF1/SprG1 systems are post-transcriptionally regulated by RNA antitoxins and encode small membrane damaging proteins. TA systems controlled by interaction between toxin protein and antitoxin RNA have been identified in S. aureus in silico, but not yet experimentally proven. A closer inspection of possible links between TA systems and S. aureus pathophysiology will reveal, if these genetic loci may represent druggable targets. The modification of a staphylococcal TA toxin to a cyclopeptide antibiotic highlights the potential of TA systems as rather untapped sources of drug discovery.

  19. NVC-422 inactivates Staphylococcus aureus toxins.

    PubMed

    Jekle, Andreas; Yoon, Jungjoo; Zuck, Meghan; Najafi, Ramin; Wang, Lu; Shiau, Timothy; Francavilla, Charles; Rani, Suriani Abdul; Eitzinger, Christian; Nagl, Markus; Anderson, Mark; Debabov, Dmitri

    2013-02-01

    Bacterial pathogens have specific virulence factors (e.g., toxins) that contribute significantly to the virulence and infectivity of microorganisms within the human hosts. Virulence factors are molecules expressed by pathogens that enable colonization, immunoevasion, and immunosuppression, obtaining nutrients from the host or gaining entry into host cells. They can cause pathogenesis by inhibiting or stimulating certain host functions. For example, in systemic Staphylococcus aureus infections, virulence factors such as toxic shock syndrome toxin 1 (TSST-1), staphylococcal enterotoxin A (SEA), and staphylococcal enterotoxin B (SEB) cause sepsis or toxic shock by uncontrolled stimulation of T lymphocytes and by triggering a cytokine storm. In vitro, these superantigens stimulate the proliferation of human peripheral blood mononuclear cells (PBMC) and the release of many cytokines. NVC-422 (N,N-dichloro-2,2-dimethyltaurine) is a broad-spectrum, fast-acting topical anti-infective agent against microbial pathogens, including antibiotic-resistant microbes. Using mass spectrometry, we demonstrate here that NVC-422 oxidizes methionine residues of TSST-1, SEA, SEB, and exfoliative toxin A (ETA). Exposure of virulence factors to 0.1% NVC-422 for 1 h prevented TSST-1-, SEA-, SEB-, and ETA-induced cell proliferation and cytokine release. Moreover, NVC-422 also delayed and reduced the protein A- and clumping factor-associated agglutination of S. aureus cultures. These results show that, in addition to its well-described direct microbicidal activity, NVC-422 can inactivate S. aureus virulence factors through rapid oxidation of methionines.

  20. Immunopathogenesis of Staphylococcus aureus pulmonary infection

    PubMed Central

    Parker, Dane; Prince, Alice

    2013-01-01

    Staphylococcus aureus is a common human pathogen highly evolved as both a component of the commensal flora and as a major cause of invasive infection. Severe respiratory infection due to staphylococci has been increasing due to the prevalence of more virulent USA300 CA-MRSA strains in the general population. The ability of S. aureus to adapt to the milieu of the respiratory tract has facilitated its emergence as a respiratory pathogen. Its metabolic versatility, the ability to scavenge iron, coordinate gene expression, and the horizontal acquisition of useful genetic elements have all contributed to its success as a component of the respiratory flora, in hospitalized patients, as a complication of influenza and in normal hosts. The expression of surface adhesins facilitates its persistence in the airways. In addition, the highly sophisticated interactions of the multiple S. aureus virulence factors, particularly the α-hemolysin and protein A, with diverse immune effectors in the lung such as ADAM10, TNFR1, EGFR, immunoglobulin, and complement all contribute to the pathogenesis of staphylococcal pneumonia. PMID:22037948

  1. The Innate Immune Response Against Staphylococcus aureus.

    PubMed

    Bekeredjian-Ding, Isabelle; Stein, Christoph; Uebele, Julia

    2015-12-15

    The innate immune system harbors a multitude of different receptor systems and cells that are constantly prepared to sense and eliminate invading microbial pathogens. Staphylococcus aureus enters the body on its exposed epithelial surfaces, e.g., on skin and mucosa. The initial interaction with epithelial cells is governed by Toll-like receptor (TLR)-2-mediated local production of soluble mediators, including cytokines, chemokines, and antimicrobial peptides. The overall goal is to achieve a steady state of immune mediators and colonizing bacteria. Following cell and tissue invasion clearance of bacteria depends on intracellular microbial sensors and subsequent activation of the inflammasomes. Tissue-resident mast cells and macrophages recruit neutrophils, macrophages, and NK cells. This inflammatory response supports the generation of IL-17 producing NKT, γδ T cells, and T helper cells. Local dendritic cells migrate to the lymph nodes and fine-tune the adaptive immune response. The scope of this chapter is to provide an overview on the major cell types and receptors involved in innate immune defense against S. aureus. By segregating the different stages of infection from epithelial barrier to intracellular and systemic infection, this chapter highlights the different qualities of the innate immune response to S. aureus at different stages of invasiveness.

  2. Destruction of Staphylococcus aureus during frankfurter processing.

    PubMed Central

    Palumbo, S A; Smith, J L; Kissinger, J C

    1977-01-01

    We studied the thermal resistance of Staphylococcus aureus during frankfurter processing in respect to whether staphylococci are killed by the heating step of the process and whether heat injury interferes with the quantitative estimation of the survivors. With S. aureus 198E, heat injury could be demonstrated only when large numbers of cells (10(8)/g) were present and at a product temperature of 140 degrees F (60 degrees C). On tryptic soy agar and tryptic soy agar plus 7% NaCl media, at temperatures less than 140 degrees F, the counts were virtually identical; above 140 degrees F, the counts converged, with the organisms dying so rapidly that heat injury was not demonstrable. Heat injury was thus judged not to interfere with the quantitative estimation of staphylococci surviving the normal commercial heating given frankfurters. By using a combination of direct plating on tryptic soy agar and a most-probable-number technique, we detected no viable cells (less than 0.3/g) of several strains of S. aureus in frankfurters heated to 160 degrees F (71.1 degrees C). This temperature is compatible with the normal final temperature to which federally inspected processors heat their frankfurters and with the temperature needed to destroy salmonellae. PMID:563701

  3. Staphylococcus aureus infections in Australasian neonatal nurseries

    PubMed Central

    Isaacs, D; Fraser, S; Hogg, G; Li, H

    2004-01-01

    Objective: To study the incidence and outcome of systemic infections with methicillin sensitive (MSSA) and methicillin resistant Staphylococcus aureus (MRSA) infections in Australasian neonatal nurseries. Methods: Prospective longitudinal study of systemic infections (clinical sepsis plus positive cultures of blood and/or cerebrospinal fluid) in 17 Australasian neonatal nurseries. Results: The incidence of early onset sepsis with S aureus, mainly MSSA, was 19 cases per 244 718 live births or 0.08 per 1000. From 1992 to 1994, MRSA infections caused only 8% of staphylococcal infections. From 1995 to 1998, there was an outbreak of MRSA infection, in two Melbourne hospitals. The outbreak resolved, after the use of topical mupirocin and improved handwashing. Babies with MRSA sepsis were significantly smaller than babies with MSSA sepsis (mean birth weight 1093 v 1617 g) and more preterm (mean gestation 27.5 v 30.3 weeks). The mortality of MRSA sepsis was 24.6% compared with 9.9% for MSSA infections. The mortality of early onset MSSA sepsis, however, was 39% (seven of 18) compared with 7.3% of late onset MSSA infection presenting more than two days after birth. Conclusions: S aureus is a rare but important cause of early onset sepsis. Late onset MRSA infections carried a higher mortality than late onset MSSA infections, but babies with early onset MSSA sepsis had a particularly high mortality. PMID:15210669

  4. Isolation of Staphylococcus aureus and Antibiotic-Resistant Staphylococcus aureus from Residential Indoor Bioaerosols

    PubMed Central

    Gandara, Angelina; Mota, Linda C.; Flores, Carissa; Perez, Hernando R.; Green, Christopher F.; Gibbs, Shawn G.

    2006-01-01

    Objective In this study we evaluated the levels of Staphylococcus aureus and antibiotic-resistant S. aureus in colony-forming units (CFU) per cubic meter of air. Design We used Andersen two-stage samplers to collect bioaerosol samples from 24 houses in El Paso, Texas, using tryptic soy agar as the collection media, followed by the replicate plate method on Chapman Stone selective medium to isolate S. aureus. The Kirby-Bauer disk diffusion method was used to determine antibiotic resistance to ampicillin, penicillin, and cefaclor, which represent two distinct classes of antibiotics. Results The average recovered concentration of respirable heterotrophic organisms found outside each home was 345.38 CFU/m3, with an average of 12.63 CFU/m3 for S. aureus. The average recovered concentration of respirable heterotrophic organisms found inside each home was 460.23 CFU/m3, with an average of 15.39 CFU/m3 for S. aureus. The respirable S. aureus recovered from inside each home had an average resistance of 54.59% to ampicillin and 60.46%. to penicillin. Presence of cefaclor-resistant and of multidrug-resistant S. aureus was the same, averaging 13.20% per house. The respirable S. aureus recovered from outside each home had an average resistance of 34.42% to ampicillin and 41.81% to penicillin. Presence of cefaclor-resistant and of multidrug-resistant S. aureus was the same, averaging 13.96% per house. Conclusions This study indicates that antibiotic-resistant bioaerosols are commonly found within residential homes. Our results also suggest that resistant strains of airborne culturable S. aureus are present in higher concentrations inside the study homes than outside the homes. PMID:17185276

  5. Staphylococcus lugdunensis, a serious pathogen in periprosthetic joint infections: comparison to Staphylococcus aureus and Staphylococcus epidermidis.

    PubMed

    Lourtet-Hascoët, J; Bicart-See, A; Félicé, M P; Giordano, G; Bonnet, E

    2016-10-01

    The aim of this study was to assess the characteristics of periprosthetic joint infection (PJI) due to Staphylococcus lugdunensis and to compare these to the characteristics of PJI due to Staphylococcus aureus and Staphylococcus epidermidis. A retrospective multicentre study including all consecutive cases of S. lugdunensis PJI (2000-2014) was performed. Eighty-eight cases of staphylococcal PJI were recorded: 28 due to S. lugdunensis, 30 to S. aureus, and 30 to S. epidermidis, as identified by Vitek 2 or API Staph (bioMérieux). Clinical symptoms were more often reported in the S. lugdunensis group, and the median delay between surgery and infection was shorter for the S. lugdunensis group than for the S. aureus and S. epidermidis groups. Regarding antibiotic susceptibility, the S. lugdunensis strains were susceptible to antibiotics and 61% of the patients could be treated with levofloxacin + rifampicin. The outcome of the PJI was favourable for 89% of patients with S. lugdunensis, 83% with S. aureus, and 97% with S. epidermidis. S. lugdunensis is an emerging pathogen with a pathogenicity quite similar to that of S. aureus. This coagulase-negative Staphylococcus must be identified precisely in PJI, in order to select the appropriate surgical treatment and antibiotics . Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  6. Sialic Acid Catabolism in Staphylococcus aureus

    PubMed Central

    Olson, Michael E.; King, Jessica M.; Yahr, Timothy L.

    2013-01-01

    Staphylococcus aureus is a ubiquitous bacterial pathogen that is the causative agent of numerous acute and chronic infections. S. aureus colonizes the anterior nares of a significant portion of the healthy adult population, but the mechanisms of colonization remain incompletely defined. Sialic acid (N-acetylneuraminic acid [Neu5Ac]) is a bioavailable carbon and nitrogen source that is abundant on mucosal surfaces and in secretions in the commensal environment. Our findings demonstrate that Neu5Ac can serve as an S. aureus carbon source, and we have identified a previously uncharacterized chromosomal locus (nan) that is required for Neu5Ac utilization. Molecular characterization of the nan locus indicates that it contains five genes, organized into four transcripts, and the genes were renamed nanE, nanR, nanK, nanA, and nanT. Initial studies with gene deletions indicate that nanT, predicted to encode the Neu5Ac transporter, and nanA and nanE, predicted to encode catabolic enzymes, are essential for growth on Neu5Ac. Furthermore, a nanE deletion mutant exhibits a growth inhibition phenotype in the presence of Neu5Ac. Transcriptional fusions and Northern blot analyses indicate that NanR represses the expression of both the nanAT and nanE transcripts, which can be relieved with Neu5Ac. Electrophoretic mobility studies demonstrate that NanR binds to the nanAT and nanE promoter regions, and the Neu5Ac catabolic intermediate N-acetylmannosamine-6-phosphate (ManNAc-6P) relieves NanR promoter binding. Taken together, these data indicate that the nan gene cluster is essential for Neu5Ac utilization and may perform an important function for S. aureus survival in the host. PMID:23396916

  7. [Staphylococcus aureus in bulk milk samples].

    PubMed

    Benda, P; Vyletĕlová, M

    1995-07-01

    In the years 1993-1994 the occurrence of Staphylococcus aureus was investigated in bulk milk samples in the area where a Baby Food Factory at Zábreh in Moravia is located, and in Bruntál, Zlín and Policka districts. Evaluation of the results was based on ECC Directive 92/46, while the dynamics of S. aureus presence was followed for the whole period of observation as well as in the particular seasons. A total of 4,485 samples was processed. Out of these, 50.7% contained less than 100 CFU/ml of S. aureus, 41.4% contained 100-500 CFU/ml, 6.73% 500-2,000 CFU/ml and 1.14% contained more than 2,000 CFU/ml (Fig. 1). The samples were divided into three categories: private new-established farms, cooperative and State-owned enterprises in the area of the Zábĕh Factory and others (Zlín, Bruntál and Policka districts). There were highly significant differences in the content of staphylococci (P = 0.01%) between the three categories of samples. Ninety-eight percent of samples from private farms, 96% samples from the Zábreh Factory area and 85% of the other samples comply with the regulation EEC 92/64 (Tab. I) for raw cow's milk for the manufacture of products "made with raw milk" whose manufacturing process does not involve any heat treatment (Fig. 2). The occurrence of S. aureus in the Zábreh Factory area shows an expressive seasonal dynamics (P = 0.005%) with maximum values in winter months (December-March) and minimum values in summer months (July-October)-Fig. 3. The same relationship can be seen on more extensive data files for the particular producers (Fig. 4).(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Laboratory Maintenance of Methicillin-Resistant Staphylococcus aureus (MRSA)

    PubMed Central

    Vitko, Nicholas P.; Richardson, Anthony R.

    2014-01-01

    Staphylococcus aureus is an important bacterial pathogen in the hospital and community settings, especially Staphylococcus aureus clones that exhibit methicillin-resistance (MRSA). Many strains of S. aureus are utilized in the laboratory, underscoring the genetic differences inherent in clinical isolates. S. aureus grows quickly at 37°C with aeration in rich media (e.g. BHI) and exhibits a preference for glycolytic carbon sources. Furthermore, S. aureus has a gold pigmentation, exhibits β-hemolysis, and is catalase and coagulase positive. The four basic laboratory protocols presented in this unit describe how to culture S. aureus on liquid and solid media, how to identify S. aureus strains as methicillin resistant, and how to generate a freezer stock of S. aureus for long-term storage. PMID:23408135

  9. Laboratory maintenance of methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Vitko, Nicholas P; Richardson, Anthony R

    2013-02-01

    Staphylococcus aureus is an important bacterial pathogen in the hospital and community settings, especially Staphylococcus aureus clones that exhibit methicillin-resistance (MRSA). Many strains of S. aureus are utilized in the laboratory, underscoring the genetic differences inherent in clinical isolates. S. aureus grows quickly at 37°C with aeration in rich media (e.g., BHI) and exhibits a preference for glycolytic carbon sources. Furthermore, S. aureus has a gold pigmentation, exhibits β-hemolysis, and is catalase and coagulase positive. The four basic laboratory protocols presented in this unit describe how to culture S. aureus on liquid and solid media, how to identify S. aureus strains as methicillin resistant, and how to generate a freezer stock of S. aureus for long-term storage. © 2013 by John Wiley & Sons, Inc.

  10. AN EXPERIMENTAL STUDY OF OPSONIC IMMUNITY TO STAPHYLOCOCCUS AUREUS

    PubMed Central

    Meakins, J. C.

    1910-01-01

    1. The administration of Staphylococcus aureus, killed by heat (vaccine), produces a high degree of opsonic immunity in rabbits. 2. Such increase of opsonin affords protection against living virulent staphylococcus in direct proportion to the amount of opsonins present in the serum and complete recovery may follow subsequent inoculation, if the opsonic power be high. 3. Frequent administration of vaccines may produce a diminution of the opsonic power of the serum. 4. Immune opsonins are most active against the homologous strain of Staphylococcus aureus, but are only slightly less active against heterologous strains. 5. Infections of the human body by Staphylococcus aureus may cause great increase of opsonins. 6. Vaccines prepared from Staphylococcus aureus may produce a high degree of opsonic immunity in man. PMID:19867314

  11. Immunogenicity of Staphylococcus aureus delta-toxin.

    PubMed Central

    Nolte, F S; Kapral, F A

    1981-01-01

    Studies were conducted to determine the immunogenicity of purified Staphylococcus aureus delta-toxin. Rabbits and guinea pigs immunized with delta-toxin incorporated into a multiple antibody, whereas animals given toxin in saline or toxin in saline with Tween 80 did not produce antibody. The immunoglobulin G (IgG) fraction isolated by chromatography on protein A-Sepharose was examined for the presence of anti-delta-toxin antibody by immunoelectrophoresis, immunodiffusion, quantitative precipitation tests, affinity chromatography, and toxin neutralization tests. Although delta-toxin-specific IgG precipitated the toxin in agar gels, the antibody did not neutralize the toxin's hemolytic activity. Delta-toxin binding to human erythrocyte membranes was demonstrated by indirect immunofluorescent staining of toxin-treated erythrocytes. Images PMID:7014461

  12. Characterization of a Staphylococcus aureus Bacteriocin

    PubMed Central

    Gagliano, V. J.; Hinsdill, R. D.

    1970-01-01

    The bacteriocin produced by a strain of Staphylococcus aureus has been isolated and designated staphylococcin (414), and a study was made of its chemical, physical, and biological properties. The staphylococcin is released in appreciable quantities after breakage of the cells and can be purified through differential centrifugation and column chromatography. In the native state, it appears to be a lipoprotein-carbohydrate complex with a molecular weight in excess of 200,000. The complex can be dissociated by sodium dodecyl sulfate into smaller subunits which retain activity. The gross chemical and physical properties of the bacteriocin closely resemble those ascribed to certain preparations of cell membranes. Staphylococcin (414) is not a lytic enzyme like lysostaphin and does not have the same spectrum of activity. Like other bacteriocins from gram-positive microorganisms, it does not inhibit any gram-negative bacteria, but does inhibit several other genera. Images PMID:5473880

  13. Efficacy of lytic Staphylococcus aureus bacteriophage against multidrug-resistant Staphylococcus aureus in mice.

    PubMed

    Oduor, Joseph Michael Ochieng'; Onkoba, Nyamongo; Maloba, Fredrick; Arodi, Washingtone Ouma; Nyachieo, Atunga

    2016-11-24

    The use of bacteriophages as an alternative treatment method against multidrug-resistant bacteria has not been explored in Kenya. This study sought to determine the efficacy of environmentally obtained lytic bacteriophage against multidrug-resistant Staphylococcus aureus (MDRSA) bacterium in mice. Staphylococcus aureus bacterium and S. aureus-specific lytic phage were isolated from sewage and wastewater collected within Nairobi County, Kenya. Thirty mice were randomly assigned into three groups: MDRSA infection group (n = 20), phage-infection group (n = 5), and non-infection group (n = 5). The MDRSA infection group was further subdivided into three groups: clindamycin treatment (8 mg/kg; n = 5), lytic phage treatment (108 PFU/mL (n = 5), and a combination treatment of clindamycin and lytic phage (n = 5). Treatments were done at either 24 or 72 hours post-infection (p.i), and data on efficacy, bacterial load, and animal physical health were collected. Treatment with phage was more effective (100%) than with clindamycin (62.25% at 24 hours p.i and 87.5% at 72 hours p.i.) or combination treatment (75% at 24 hours p.i. and 90% at 72 hours p.i.) (p < 0.001). The results show that the environmentally obtained S. aureus lytic bacteriophage has therapeutic potential against MDRSA bacterium in mice.

  14. PYRITHIAMINE ADAPTATION OF STAPHYLOCOCCUS AUREUS I.

    PubMed Central

    Das, S. K.; Chatterjee, G. C.

    1962-01-01

    Das, S. K. (University of Calcutta, Calcutta, India) and G. C. Chatterjee. Pyrithiamine adaptation of Staphylococcus aureus. I. Adaptation and carbohydrate utilization. J. Bacteriol. 83:1251–1259. 1962.—Staphylococcus aureus has been adapted to pyrithiamine, a thiamine analogue; as a result of this adaptation, the color of the pigment of the organism changes from orange-yellow to lemon-yellow. The adaptation is reversible; the adapted strain will revert after repeated subculture in a medium containing thiamine and no pyrithiamine. Of the major biochemical alterations resulting from adaptation, severe depression in glucose utilization and simultaneous stimulation of acetate utilization have been noticed. The effect of metabolic inhibitors on the utilization of glucose and acetate has also been studied. By measuring the rate of formation of C14O2 from glucose-1-C14 and glucose-6-C14, it has been observed that the reduction in C14O2 formation from glucose-1-C14 by the adapted organism is much more than that obtained from glucose-6-C14, causing thereby a decreased metabolic ratio of these two substrates after such adaptation. Relative to the normal strain, the adapted strain utilizes acetate-C14 at a much faster rate, both in the formation of C14O2 and also in the incorporation of C14 into the protein and lipid fractions; the rate of formation of C14O2 from pyruvate-1-C14 is not greatly altered. It has been postulated that there is a partial blocking of the pentose phosphate cycle, because of the lowered glucose-1-C14 utilization, and simultaneous stimulation of the tricarboxylic acid cycle; or perhaps the initiation of some other route after pyrithiamine adaptation would account for the great increase in acetate utilization. PMID:13883630

  15. Activity of Gallidermin on Staphylococcus aureus and Staphylococcus epidermidis Biofilms

    PubMed Central

    Saising, Jongkon; Dube, Linda; Ziebandt, Anne-Kathrin; Voravuthikunchai, Supayang Piyawan; Nega, Mulugeta

    2012-01-01

    Due to their abilities to form strong biofilms, Staphylococcus aureus and Staphylococcus epidermidis are the most frequently isolated pathogens in persistent and chronic implant-associated infections. As biofilm-embedded bacteria are more resistant to antibiotics and the immune system, they are extremely difficult to treat. Therefore, biofilm-active antibiotics are a major challenge. Here we investigated the effect of the lantibiotic gallidermin on two representative biofilm-forming staphylococcal species. Gallidermin inhibits not only the growth of staphylococci in a dose-dependent manner but also efficiently prevents biofilm formation by both species. The effect on biofilm might be due to repression of biofilm-related targets, such as ica (intercellular adhesin) and atl (major autolysin). However, gallidermin's killing activity on 24-h and 5-day-old biofilms was significantly decreased. A subpopulation of 0.1 to 1.0% of cells survived, comprising “persister” cells of an unknown genetic and physiological state. Like many other antibiotics, gallidermin showed only limited activity on cells within mature biofilms. PMID:22926575

  16. Activity of gallidermin on Staphylococcus aureus and Staphylococcus epidermidis biofilms.

    PubMed

    Saising, Jongkon; Dube, Linda; Ziebandt, Anne-Kathrin; Voravuthikunchai, Supayang Piyawan; Nega, Mulugeta; Götz, Friedrich

    2012-11-01

    Due to their abilities to form strong biofilms, Staphylococcus aureus and Staphylococcus epidermidis are the most frequently isolated pathogens in persistent and chronic implant-associated infections. As biofilm-embedded bacteria are more resistant to antibiotics and the immune system, they are extremely difficult to treat. Therefore, biofilm-active antibiotics are a major challenge. Here we investigated the effect of the lantibiotic gallidermin on two representative biofilm-forming staphylococcal species. Gallidermin inhibits not only the growth of staphylococci in a dose-dependent manner but also efficiently prevents biofilm formation by both species. The effect on biofilm might be due to repression of biofilm-related targets, such as ica (intercellular adhesin) and atl (major autolysin). However, gallidermin's killing activity on 24-h and 5-day-old biofilms was significantly decreased. A subpopulation of 0.1 to 1.0% of cells survived, comprising "persister" cells of an unknown genetic and physiological state. Like many other antibiotics, gallidermin showed only limited activity on cells within mature biofilms.

  17. Antibacterial mechanism of fraxetin against Staphylococcus aureus.

    PubMed

    Wang, Haiting; Zou, Dan; Xie, Kunpeing; Xie, Mingjie

    2014-11-01

    Fraxetin is one of the main constituents of the traditional medicinal plant Fraxinus rhynchophylla. The inhibitory effect of fraxetin on various bacterial strains has been extensively reported, however, its mechanism of action on bacterial cells remains to be elucidated. In the present study, the antibacterial mechanism of fraxetin on Staphylococcus aureus was systematically investigated by examining its effect on cell membranes, protein synthesis, nucleic acid content and topoisomerase activity. The results indicated that fraxetin increased the permeability of the cell membrane but did not render it permeable to macromolecules, such as DNA and RNA. Additionally, the quantity of protein, DNA and RNA decreased to 55.74, 33.86 and 48.96%, respectively following treatment with fraxetin for 16 h. The activity of topoisomerase I and topoisomerase II were also markedly inhibited as fraxetin concentration increased. The result of the ultraviolet‑visible spectrophotometry demonstrated that the DNA characteristics exhibited a blue shift and hypochromic effect following treatment with fraxetin. These results indicated that fraxetin had a marked inhibitory effect on S.aureus proliferation. Further mechanistic studies showed that fraxetin could disrupt nucleic acid and protein synthesis by preventing topoisomerase from binding to DNA.

  18. Binary IS Typing for Staphylococcus aureus

    PubMed Central

    Budding, Andries E.; Vandenbroucke-Grauls, Christina M. J. E.; Melles, Damian C.; van Duijkeren, Engeline; Kluytmans, Jan A.; Savelkoul, Paul H. M.

    2010-01-01

    Background We present an easily applicable test for rapid binary typing of Staphylococcus aureus: binary interspace (IS) typing. This test is a further development of a previously described molecular typing technique that is based on length polymorphisms of the 16S-23S rDNA interspace region of S. aureus. Methodology/Principal Findings A novel approach of IS-typing was performed in which binary profiles are created. 424 human and animal derived MRSA and MSSA isolates were tested and a subset of these isolates was compared with multi locus sequence typing (MLST) and Amplified Fragment Length Polymorphism (AFLP). Binary IS typing had a high discriminatory potential and a good correlation with MLST and AFLP. Conclusions/Significance Binary IS typing is easy to perform and binary profiles can be generated in a standardized fashion. These two features, combined with the high correlation with MLST clonal complexes, make the technique applicable for large-scale inter-laboratory molecular epidemiological comparisons. PMID:21060683

  19. Hidden Staphylococcus aureus Carriage: Overrated or Underappreciated?

    PubMed Central

    2016-01-01

    ABSTRACT Staphylococcus aureus is a persistent companion bacterial species in one-third of humankind. Reservoirs include the nasal and nasopharyngeal cavities, skin, and gastrointestinal (GI) tract. Despite earlier claims that colonization of individuals is caused by clonal organisms, next-generation sequencing (NGS) has revealed that resident type heterogeneity is not exceptional. Carriage, whether overt or hidden, is correlated with a risk of autoinfection. In a recent article in mBio, it was shown that, based on staphylococcal genome sequencing, low-level GI persistence may cause long-term nosocomial outbreaks [L. Senn et al., 7(1):e02039-15, 2016, doi:10.1128/mBio.02039-15]. Institutional endemicity with methicillin-resistant S. aureus (MRSA) sequence type 228 (ST228) is shown to originate not from high-level nasal carriage or poor compliance with infection control practice but from low-grade asymptomatic GI colonization. This shows the power of NGS in elucidating staphylococcal epidemiology and, even more important, demonstrates that (drug-resistant) microorganisms may possess stealthy means of persistence. Identifying these persistence mechanisms is key to successful infection control. PMID:26884429

  20. Where Does a Staphylococcus aureus Vaccine Stand?

    PubMed Central

    Fowler, Vance G.; Proctor, Richard A.

    2014-01-01

    In this review, we examine the current status of Staphylococcus aureus vaccine development and the prospects for future vaccines. Examination of the clinical trials to date show that murine models have not predicted success in humans for active or passive immunization. A key factor in the failure to develop a vaccine to prevent S. aureus infections comes from our relatively limited knowledge of human protective immunity. More recent reports on the elements of the human immune response to staphylococci are analysed. In addition, there is some controversy concerning the role of antibodies for protecting humans, and these data are reviewed. From a review of the current state of understanding of staphylococcal immunity, a working model is proposed. Some new work has provided some initial candidate biomarker(s) to predict outcomes of invasive infections and to predict the efficacy of antibiotic therapy in humans. We conclude by looking to the future through the perspective of lessons gleaned from the clinical vaccine trials. PMID:24476315

  1. Food Poisoning and Staphylococcus aureus Enterotoxins

    PubMed Central

    Argudín, María Ángeles; Mendoza, María Carmen; Rodicio, María Rosario

    2010-01-01

    Staphylococcus aureus produces a wide variety of toxins including staphylococcal enterotoxins (SEs; SEA to SEE, SEG to SEI, SER to SET) with demonstrated emetic activity, and staphylococcal-like (SEl) proteins, which are not emetic in a primate model (SElL and SElQ) or have yet to be tested (SElJ, SElK, SElM to SElP, SElU, SElU2 and SElV). SEs and SEls have been traditionally subdivided into classical (SEA to SEE) and new (SEG to SElU2) types. All possess superantigenic activity and are encoded by accessory genetic elements, including plasmids, prophages, pathogenicity islands, vSa genomic islands, or by genes located next to the staphylococcal cassette chromosome (SCC) implicated in methicillin resistance. SEs are a major cause of food poisoning, which typically occurs after ingestion of different foods, particularly processed meat and dairy products, contaminated with S. aureus by improper handling and subsequent storage at elevated temperatures. Symptoms are of rapid onset and include nausea and violent vomiting, with or without diarrhea. The illness is usually self-limiting and only occasionally it is severe enough to warrant hospitalization. SEA is the most common cause of staphylococcal food poisoning worldwide, but the involvement of other classical SEs has been also demonstrated. Of the new SE/SEls, only SEH have clearly been associated with food poisoning. However, genes encoding novel SEs as well as SEls with untested emetic activity are widely represented in S. aureus, and their role in pathogenesis may be underestimated. PMID:22069659

  2. Cytoplasmic peptidoglycan intermediate levels in Staphylococcus aureus.

    PubMed

    Vemula, Harika; Ayon, Navid J; Gutheil, William G

    2016-02-01

    Intracellular cytoplasmic peptidoglycan (PG) intermediate levels were determined in Staphylococcus aureus during log-phase growth in enriched media. Levels of UDP-linked intermediates were quantitatively determined using ion pairing LC-MS/MS in negative mode, and amine intermediates were quantitatively determined stereospecifically as their Marfey's reagent derivatives in positive mode. Levels of UDP-linked intermediates in S. aureus varied from 1.4 μM for UDP-GlcNAc-Enolpyruvyate to 1200 μM for UDP-MurNAc. Levels of amine intermediates (L-Ala, D-Ala, D-Ala-D-Ala, L-Glu, D-Glu, and L-Lys) varied over a range of from 860 μM for D-Ala-D-Ala to 30-260 mM for the others. Total PG was determined from the D-Glu content of isolated PG, and used to estimate the rate of PG synthesis (in terms of cytoplasmic metabolite flux) as 690 μM/min. The total UDP-linked intermediates pool (2490 μM) is therefore sufficient to sustain growth for 3.6 min. Comparison of UDP-linked metabolite levels with published pathway enzyme characteristics demonstrates that enzymes on the UDP-branch range from >80% saturation for MurA, Z, and C, to <5% saturation for MurB. Metabolite levels were compared with literature values for Escherichia coli, with the major difference in UDP-intermediates being the level of UDP-MurNAc, which was high in S. aureus (1200 μM) and low in E. coli (45 μM).

  3. Methicillin resistant Staphylococcus aureus in Ethiopia: a meta-analysis.

    PubMed

    Eshetie, Setegn; Tarekegn, Fentahun; Moges, Feleke; Amsalu, Anteneh; Birhan, Wubet; Huruy, Kahsay

    2016-11-21

    The burden of methicillin resistant Staphylococcus aureus is a major public health concern worldwide; however the overall epidemiology of multidrug resistant strains is neither coordinated nor harmonized, particularly in developing countries including Ethiopia. Therefore, the aim of this meta-analysis was to assess the burden of methicillin resistant Staphylococcos aureus and its antibiotic resistance pattern in Ethiopia at large. PubMed, Google Scholar, and lancet databases were searched and a total of 20 studies have been selected for meta-analysis. Six authors have independently extracts data on the prevalence of methicillin resistant Staphylococcus aureus among clinical isolates of Staphylococcus aureus. Statistical analysis was achieved by using Open meta-analyst (version 3.13) and Comprehensive meta-analysis (version 3.3) softwares. The overall prevalence of methicillin resistant Staphylococcus aureus and its antibiotic resistance pattern were pooled by using the forest plot, table and figure with 95% CI. The pooled prevalence of methicillin resistant Staphylococcus aureus was 32.5% (95% CI, 24.1 to 40.9%). Moreover, methicillin resistant Staphylococcus aureus strains were found to be highly resistant to penicillin, ampicillin, erythromycin, and amoxicillin, with a pooled resistance ratio of 99.1, 98.1, 97.2 and 97.1%, respectively. On the other hand, comparably low levels of resistance ratio were noted to vancomycin, 5.3%. The overall burden of methicillin resistant Staphylococcus aureus is considerably high, besides these strains showed extreme resistance to penicillin, ampicillin, erythromycin and amoxicillin. In principle, appropriate use of antibiotics, applying safety precautions are the key to reduce the spread of multidrug resistant strains, methicillin resistant Staphylococcus aureus in particular.

  4. Staphylococcus aureus meningitis from osteomyelitis of the spine.

    PubMed Central

    Markus, H. S.; Allison, S. P.

    1989-01-01

    Two cases of vertebral osteomyelitis presenting with secondary Staphylococcus aureus meningitis are described. In staphylococcal meningitis a search for a primary source should include the lower vertebral spine. PMID:2616438

  5. STUDIES ON THE INTERACTIONS BETWEEN COMPONENTS OF STAPHYLOCOCCUS AUREUS AND STAPHYLOCOCCUS BACTERIOPHAGE

    PubMed Central

    Morse, Stephen I.

    1962-01-01

    The cell walls of Staphylococcus aureus are capable of inactivating S. aureus bacteriophage. Furthermore, the cell walls isolated from S. aureus of a given phage type inactivate a variety of different staphylococcal bacteriophages. Under the conditions employed neither the isolated mucopeptide nor teichoic acid components of the cell walls act as bacteriophage receptor. PMID:14476346

  6. Staphylococcus aureus: methicillin-susceptible S. aureus to methicillin-resistant S. aureus and vancomycin-resistant S. aureus.

    PubMed

    Rehm, Susan J; Tice, Alan

    2010-09-15

    The evolution of methicillin-resistant and vancomycin-resistant Staphylococcus aureus has demanded serious review of antimicrobial use and development of new agents and revised approaches to prevent and overcome drug resistance. Depending on local conditions and patient risk factors, empirical therapy of suspected S. aureus infection may require coverage of drug-resistant organisms with newer agents and novel antibiotic combinations. The question of treatment with inappropriate antibiotics raises grave concerns with regard to methicillin-resistant S. aureus selection, overgrowth, and increased virulence. Several strategies to reduce the nosocomial burden of resistance are suggested, including shortened hospital stays and outpatient parenteral antimicrobial therapy of the most serious infections.

  7. Antimicrobial Activity against Intraosteoblastic Staphylococcus aureus

    PubMed Central

    Trouillet-Assant, Sophie; Riffard, Natacha; Tasse, Jason; Flammier, Sacha; Rasigade, Jean-Philippe; Chidiac, Christian; Vandenesch, François; Ferry, Tristan; Laurent, Frédéric

    2015-01-01

    Although Staphylococcus aureus persistence in osteoblasts, partly as small-colony variants (SCVs), can contribute to bone and joint infection (BJI) relapses, the intracellular activity of antimicrobials is not currently considered in the choice of treatment strategies for BJI. Here, antistaphylococcal antimicrobials were evaluated for their intraosteoblastic activity and their impact on the intracellular emergence of SCVs in an ex vivo osteoblast infection model. Osteoblastic MG63 cells were infected for 2 h with HG001 S. aureus. After killing the remaining extracellular bacteria with lysostaphin, infected cells were incubated for 24 h with antimicrobials at the intraosseous concentrations reached with standard therapeutic doses. Intracellular bacteria and SCVs were then quantified by plating cell lysates. A bactericidal effect was observed with fosfomycin, linezolid, tigecycline, oxacillin, rifampin, ofloxacin, and clindamycin, with reductions in the intracellular inocula of −2.5, −3.1, −3.9, −4.2, −4.9, −4.9, and −5.2 log10 CFU/100,000 cells, respectively (P < 10−4). Conversely, a bacteriostatic effect was observed with ceftaroline and teicoplanin, whereas vancomycin and daptomycin had no significant impact on intracellular bacterial growth. Ofloxacin, daptomycin, and vancomycin significantly limited intracellular SCV emergence. Overall, ofloxacin was the only molecule to combine an excellent intracellular activity while limiting the emergence of SCVs. These data provide a basis for refining the choice of antibiotics to prioritise in the management of BJI, justifying the combination of a fluoroquinolone for its intracellular activity with an anti-biofilm molecule, such as rifampin. PMID:25605365

  8. Bacillithiol: a key protective thiol in Staphylococcus aureus.

    PubMed

    Perera, Varahenage R; Newton, Gerald L; Pogliano, Kit

    2015-01-01

    Bacillithiol is a low-molecular-weight thiol analogous to glutathione and is found in several Firmicutes, including Staphylococcus aureus. Since its discovery in 2009, bacillithiol has been a topic of interest because it has been found to contribute to resistance during oxidative stress and detoxification of electrophiles, such as the antibiotic fosfomycin, in S. aureus. The rapid increase in resistance of methicillin-resistant Staphylococcus aureus (MRSA) to available therapeutic agents is a great health concern, and many research efforts are focused on identifying new drugs and targets to combat this organism. This review describes the discovery of bacillithiol, studies that have elucidated the physiological roles of this molecule in S. aureus and other Bacilli, and the contribution of bacillithiol to S. aureus fitness during pathogenesis. Additionally, the bacillithiol biosynthesis pathway is evaluated as a novel drug target that can be utilized in combination with existing therapies to treat S. aureus infections.

  9. The newly filed patent applications for vaccines against staphylococcus aureus.

    PubMed

    Chang, Bao-Chi; Wang, Shyh-Jen

    2017-08-28

    Staphylococcus aureus (S. aureus) frequently causes life threatening disease. To release the threat, vaccine has been proposed as a preventive intervention against the cause. However, the development of the vaccines is still in early stages. Thus, highlighting the related newly filed patent applications would stimulate further developments.

  10. Wrecking Staph's Rafts: Staphylococcus aureus No Longer Unsinkable?

    PubMed

    Rashid, Rafi; Kline, Kimberly A

    2017-07-20

    Functional membrane microdomains (FMMs) serve to spatially restrict and coordinate a diversity of cellular functions. Flotillins serve as scaffolds within FMMs, and in this issue of Cell Chemical Biology, Koch et al. (2017) show that disrupting Staphylococcus aureus scaffolds via small molecules perturbs virulence gene expression and attenuates S. aureus virulence. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Predictors of Mortality in Staphylococcus aureus Bacteremia

    PubMed Central

    Jensen, Slade O.; Vaska, Vikram L.; Espedido, Björn A.; Paterson, David L.; Gosbell, Iain B.

    2012-01-01

    Summary: Staphylococcus aureus bacteremia (SAB) is an important infection with an incidence rate ranging from 20 to 50 cases/100,000 population per year. Between 10% and 30% of these patients will die from SAB. Comparatively, this accounts for a greater number of deaths than for AIDS, tuberculosis, and viral hepatitis combined. Multiple factors influence outcomes for SAB patients. The most consistent predictor of mortality is age, with older patients being twice as likely to die. Except for the presence of comorbidities, the impacts of other host factors, including gender, ethnicity, socioeconomic status, and immune status, are unclear. Pathogen-host interactions, especially the presence of shock and the source of SAB, are strong predictors of outcomes. Although antibiotic resistance may be associated with increased mortality, questions remain as to whether this reflects pathogen-specific factors or poorer responses to antibiotic therapy, namely, vancomycin. Optimal management relies on starting appropriate antibiotics in a timely fashion, resulting in improved outcomes for certain patient subgroups. The roles of surgery and infectious disease consultations require further study. Although the rate of mortality from SAB is declining, it remains high. Future international collaborative studies are required to tease out the relative contributions of various factors to mortality, which would enable the optimization of SAB management and patient outcomes. PMID:22491776

  12. Predictors of mortality in Staphylococcus aureus Bacteremia.

    PubMed

    van Hal, Sebastian J; Jensen, Slade O; Vaska, Vikram L; Espedido, Björn A; Paterson, David L; Gosbell, Iain B

    2012-04-01

    Staphylococcus aureus bacteremia (SAB) is an important infection with an incidence rate ranging from 20 to 50 cases/100,000 population per year. Between 10% and 30% of these patients will die from SAB. Comparatively, this accounts for a greater number of deaths than for AIDS, tuberculosis, and viral hepatitis combined. Multiple factors influence outcomes for SAB patients. The most consistent predictor of mortality is age, with older patients being twice as likely to die. Except for the presence of comorbidities, the impacts of other host factors, including gender, ethnicity, socioeconomic status, and immune status, are unclear. Pathogen-host interactions, especially the presence of shock and the source of SAB, are strong predictors of outcomes. Although antibiotic resistance may be associated with increased mortality, questions remain as to whether this reflects pathogen-specific factors or poorer responses to antibiotic therapy, namely, vancomycin. Optimal management relies on starting appropriate antibiotics in a timely fashion, resulting in improved outcomes for certain patient subgroups. The roles of surgery and infectious disease consultations require further study. Although the rate of mortality from SAB is declining, it remains high. Future international collaborative studies are required to tease out the relative contributions of various factors to mortality, which would enable the optimization of SAB management and patient outcomes.

  13. Control of Staphylococcus aureus pathogenicity island excision.

    PubMed

    Mir-Sanchis, Ignacio; Martínez-Rubio, Roser; Martí, Miguel; Chen, John; Lasa, Íñigo; Novick, Richard P; Tormo-Más, María Ángeles; Penadés, José R

    2012-09-01

    Staphylococcus aureus pathogenicity islands (SaPIs) are a group of related 15-17 kb mobile genetic elements that commonly carry genes for superantigen toxins and other virulence factors. The key feature of their mobility is the induction of SaPI excision and replication by certain phages and their efficient encapsidation into specific small-headed phage-like infectious particles. Previous work demonstrated that chromosomal integration depends on the SaPI-encoded recombinase, Int. However, although involved in the process, Int alone was not sufficient to mediate efficient SaPI excision from chromosomal sites, and we expected that SaPI excision would involve an Xis function, which could be encoded by a helper phage or by the SaPI, itself. Here we report that the latter is the case. In vivo recombination assays with plasmids in Escherichia coli demonstrate that SaPI-coded Xis is absolutely required for recombination between the SaPI att(L) and att(R) sites, and that both sites, as well as their flanking SaPI sequences, are required for SaPI excision. Mutational analysis reveals that Xis is essential for efficient horizontal SaPI transfer to a recipient strain. Finally, we show that the master regulator of the SaPI life cycle, Stl, blocks expression of int and xis by binding to inverted repeats present in the promoter region, thus controlling SaPI excision.

  14. Staphylococcus aureus subsp. anaerobius strain ST1464 genome sequence

    PubMed Central

    Elbir, Haitham; Robert, Catherine; Nguyen, Ti Thien; Gimenez, Grégory; El Sanousi, Sulieman M.; Flock, Jan-Ingmar; Raoult, Didier

    2013-01-01

    Staphylococcus aureus subsp. anaerobius is responsible for Morel's disease in animals and a cause of abscess in humans. It is characterized by a microaerophilic growth, contrary to the other strains of S. aureus. The 2,604,446-bp genome (32.7% GC content) of S. anaerobius ST1464 comprises one chromosome and no plasmids. The chromosome contains 2,660 open reading frames (ORFs), 49 tRNAs and three complete rRNAs, forming one complete operon. The size of ORFs ranges between 100 to 4,600 bp except for two ORFs of 6,417 and 7,173 bp encoding segregation ATPase and non-ribosomal peptide synthase, respectively. The chromosome harbors Staphylococcus phage 2638A genome and incomplete Staphylococcus phage genome PT1028, but no detectable CRISPRS. The antibiotic resistance gene for tetracycline was found although Staphylococcus aureus subsp. anaerobius is susceptible to tetracycline in-vitro. Intact oxygen detoxification genes encode superoxide dismutase and cytochrome quinol oxidase whereas the catalase gene is impaired by a stop codon. Based on the genome, in-silico multilocus sequence typing indicates that S. aureus subsp. anaerobius emerged as a clone separated from all other S. aureus strains, illustrating host-adaptation linked to missing functions. Availability of S. aureus subsp. anaerobius genome could prompt the development of post-genomic tools for its rapid discrimination from S. aureus. PMID:24501641

  15. Intra-cellular Staphylococcus aureus alone causes infection in vivo.

    PubMed

    Hamza, T; Dietz, M; Pham, D; Clovis, N; Danley, S; Li, B

    2013-07-08

    Chronic and recurrent bone infections occur frequently but have not been explained. Staphylococcus aureus (S. aureus) is often found among chronic and recurrent infections and may be responsible for such infections. One possible reason is that S. aureus can internalize and survive within host cells and by doing so, S. aureus can evade both host defense mechanisms and most conventional antibiotic treatments. In this study, we hypothesized that intra-cellular S. aureus could induce infections in vivo. Osteoblasts were infected with S. aureus and, after eliminating extra-cellular S. aureus, inoculated into an open fracture rat model. Bacterial cultures and radiographic observations at post-operative day 21 confirmed local bone infections in animals inoculated with intra-cellular S. aureus within osteoblasts alone. We present direct in vivo evidence that intra-cellular S. aureus could be sufficient to induce bone infection in animals; we found that intra-cellular S. aureus inoculation of as low as 102 colony forming units could induce severe bone infections. Our data may suggest that intra-cellular S. aureus can "hide" in host cells during symptom-free periods and, under certain conditions, they may escape and lead to infection recurrence. Intra-cellular S. aureus therefore could play an important role in the pathogenesis of S. aureus infections, especially those chronic and recurrent infections in which disease episodes may be separated by weeks, months, or even years.

  16. INTRA-CELLULAR STAPHYLOCOCCUS AUREUS ALONE CAUSES INFECTION IN VIVO#

    PubMed Central

    Hamza, Therwa; Dietz, Matthew; Pham, Danh; Clovis, Nina; Danley, Suzanne; Li, Bingyun

    2013-01-01

    Chronic and recurrent bone infections occur frequently but have not been explained. Staphylococcus aureus (S. aureus) is often found among chronic and recurrent infections and may be responsible for such infections. One possible reason is that S. aureus can internalize and survive within host cells and by doing so, S. aureus can evade both host defense mechanisms and most conventional antibiotic treatments. In this study, we hypothesized that intra-cellular S. aureus could induce infections in vivo. Osteoblasts were infected with S. aureus and, after eliminating extra-cellular S. aureus, inoculated into an open fracture rat model. Bacterial cultures and radiographic observations at post-operative day 21 confirmed local bone infections in animals inoculated with intra-cellular S. aureus within osteoblasts alone. We present direct in vivo evidence that intra-cellular S. aureus could be sufficient to induce bone infection in animals; we found that intra-cellular S. aureus inoculation of as low as 102 colony forming units could induce severe bone infections. Our data may suggest that intra-cellular S. aureus can “hide” in host cells during symptom-free periods and, under certain conditions, they may escape and lead to infection recurrence. Intra-cellular S. aureus therefore could play an important role in the pathogenesis of S. aureus infections, especially those chronic and recurrent infections in which disease episodes may be separated by weeks, months, or even years. PMID:23832687

  17. Bovine Staphylococcus aureus: diagnostic properties of specific media.

    PubMed

    Graber, H U; Pfister, S; Burgener, P; Boss, R; Meylan, M; Hummerjohann, J

    2013-08-01

    As accurate discrimination between Staphylococcus (S.) aureus and NSA (non-S. aureus staphylococci) involved in bovine mastitis is essential in terms of clinical prognosis and outcome, the aim of this study was to reevaluate the classical bacteriological procedures to identify these agents. Various media and the coagulase tube test were investigated using 116 strains of S. aureus and 115 of NSA, all isolated from cows with spontaneous intramammary infections (IMI). Furthermore, 25 NSA reference strains were analyzed. The study demonstrated that a few media were appropriate for differentiating S. aureus from NSA, provided that the staphylococci were isolated from bovine IMI. Evaluation of hemolysis further revealed that double or incomplete hemolysis are specific for S. aureus and are, therefore, a decisive diagnostic criterion. For strains showing complete hemolysis, maximal discrimination between S. aureus and NSA was observed by subculturing them on CHROMagar Staph. aureus. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Antimicrobial drug resistance of Staphylococcus aureus in dairy products

    PubMed Central

    Sasidharan, S; Prema, B; Yoga, Latha L

    2011-01-01

    Objective To evaluate the prevalence of multidrug resistant Staphylococcus aureus (S. aureus) in dairy products. Methods Isolation and identification of S. aureus were performed in 3 dairy-based food products. The isolates were tested for their susceptibility to 5 different common antimicrobial drugs. Results Of 50 samples examined, 5 (10%) were contaminated with S. aureus. Subsequently, the 5 isolates were subjected to antimicrobial resistance pattern using five antibiotic discs (methicillin, vancomycin, kanamycin, chloramphenicol and tetracycline). Sample 29 showed resistance to methicillin and vancomycin. Sample 18 showed intermediate response to tetracycline. The other samples were susceptible to all the antibiotics tested. Conclusions The results provide preliminary data on sources of food contamination which may act as vehicles for the transmission of antimicrobial-resistant Staphylococcus. Therefore, it enables us to develop preventive strategies to avoid the emergence of new strains of resistant S. aureus. PMID:23569742

  19. A high molecular weight protein from Staphylococcus intermedius cross-reacts with Staphylococcus aureus enterotoxin antibodies.

    PubMed

    Laffan, J J; Petras, P; Ferguson, K P; Lambe, D W

    1996-01-01

    Enterotoxin production by Staphylococcus species other than Staphylococcus aureus has been reported. Staphylococcus strains (104 in toto) representing twelve species and subspecies were examined for enterotoxins using a commercial staphylococcal enterotoxin ELISA immunoassay (TECRA, International Bioproducts). Staphylococcus intermedius (24 strains) and S. aureus (7 strains) were positive with this test. Western blots of S. aureus exoproteins demonstrated proteins of approximately 30 kD, consistent with known staphylococcal enterotoxins. The major antigen in all S. intermedius strains, a 75 kD protein, was not analogous to previously described staphylococcal enterotoxins. This protein was unique to S. intermedius. Gel filtration data indicate that the protein is a subunit of a larger protein in vivo. The 75 kD protein cross-reacts with several enterotoxin antibodies. It is unclear whether the protein is a toxin, but its homology with S. aureus enterotoxins may indicate a shared toxic region, or this protein may create false positive results in screening for enterotoxin.

  20. Alpha-toxin of Staphylococcus aureus.

    PubMed Central

    Bhakdi, S; Tranum-Jensen, J

    1991-01-01

    Alpha-toxin, the major cytotoxic agent elaborated by Staphylococcus aureus, was the first bacterial exotoxin to be identified as a pore former. The protein is secreted as a single-chain, water-soluble molecule of Mr 33,000. At low concentrations (less than 100 nM), the toxin binds to as yet unidentified, high-affinity acceptor sites that have been detected on a variety of cells including rabbit erythrocytes, human platelets, monocytes and endothelial cells. At high concentrations, the toxin additionally binds via nonspecific absorption to lipid bilayers; it can thus damage both cells lacking significant numbers of the acceptor and protein-free artificial lipid bilayers. Membrane damage occurs in both cases after membrane-bound toxin molecules collide via lateral diffusion to form ring-structured hexamers. The latter insert spontaneously into the lipid bilayer to form discrete transmembrane pores of effective diameter 1 to 2 nm. A hypothetical model is advanced in which the pore is lined by amphiphilic beta-sheets, one surface of which interacts with lipids whereas the other repels apolar membrane constitutents to force open an aqueous passage. The detrimental effects of alpha-toxin are due not only to the death of susceptible targets, but also to the presence of secondary cellular reactions that can be triggered via Ca2+ influx through the pores. Well-studied phenomena include the stimulation of arachidonic acid metabolism, triggering of granule exocytosis, and contractile dysfunction. Such processes cause profound long-range disturbances such as development of pulmonary edema and promotion of blood coagulation.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:1779933

  1. Methicillin-resistant Staphylococcus aureus in animals.

    PubMed

    Weese, J Scott

    2010-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a critically important human pathogen that is also an emerging concern in veterinary medicine and animal agriculture. It is present in a wide range of animal species, including dogs, cats, rabbits, horses, cattle, pigs, poultry, and exotic species, both as a cause of infection and in healthy carriers. Identification of MRSA in various species and in food has led to concerns about the roles of animals, both pets and livestock, in the epidemiology of MRSA infection and colonization in humans. There is evidence of the role of food animals in human MRSA infections in some countries and of pets as a possible source of human infection. Some groups of individuals who work closely with animals, such as veterinarians, have high MRSA colonization rates. This article includes discussions of MRSA in human medicine, animals, and food, as well as its interspecies transmission, colonization, infection, strains, and affected populations. However, clear answers are lacking in many of these areas and limited studies may lead to premature conclusions. It is certain that animals are a source of human MRSA infection in some circumstances--but humans may also serve as sources of infection in animals. Changes in the epidemiology of MRSA in one species may be reflected in changes in other species. The true scope of MRSA in animals and its impact on human health are still only superficially understood, but it is clear that MRSA is a potentially important veterinary and public health concern that requires a great deal more study to enhance understanding and effective response.

  2. Comparative genomic analysis of the genus Staphylococcus including Staphylococcus aureus and its newly described sister species Staphylococcus simiae

    PubMed Central

    2012-01-01

    Background Staphylococcus belongs to the Gram-positive low G + C content group of the Firmicutes division of bacteria. Staphylococcus aureus is an important human and veterinary pathogen that causes a broad spectrum of diseases, and has developed important multidrug resistant forms such as methicillin-resistant S. aureus (MRSA). Staphylococcus simiae was isolated from South American squirrel monkeys in 2000, and is a coagulase-negative bacterium, closely related, and possibly the sister group, to S. aureus. Comparative genomic analyses of closely related bacteria with different phenotypes can provide information relevant to understanding adaptation to host environment and mechanisms of pathogenicity. Results We determined a Roche/454 draft genome sequence for S. simiae and included it in comparative genomic analyses with 11 other Staphylococcus species including S. aureus. A genome based phylogeny of the genus confirms that S. simiae is the sister group to S. aureus and indicates that the most basal Staphylococcus lineage is Staphylococcus pseudintermedius, followed by Staphylococcus carnosus. Given the primary niche of these two latter taxa, compared to the other species in the genus, this phylogeny suggests that human adaptation evolved after the split of S. carnosus. The two coagulase-positive species (S. aureus and S. pseudintermedius) are not phylogenetically closest but share many virulence factors exclusively, suggesting that these genes were acquired by horizontal transfer. Enrichment in genes related to mobile elements such as prophage in S. aureus relative to S. simiae suggests that pathogenesis in the S. aureus group has developed by gene gain through horizontal transfer, after the split of S. aureus and S. simiae from their common ancestor. Conclusions Comparative genomic analyses across 12 Staphylococcus species provide hypotheses about lineages in which human adaptation has taken place and contributions of horizontal transfer in pathogenesis. PMID

  3. Recent initiatives to reduce the spread of meticillin-resistant Staphylococcus aureus.

    PubMed

    Wilcox, Mark H

    2009-07-01

    Recent initiatives have achieved marked reductions in meticillin-resistant Staphylococcus aureus bacteraemias. However, the relative effectiveness of prevention interventions is unclear. Initiatives to control meticillin-resistant Staphylococcus aureus have tended to ignore the benefits of altering antimicrobial prescribing.

  4. Staphylococcus aureus infections in New Zealand, 2000-2011.

    PubMed

    Williamson, Deborah A; Zhang, Jane; Ritchie, Stephen R; Roberts, Sally A; Fraser, John D; Baker, Michael G

    2014-07-01

    The incidence rate for invasive and noninvasive Staphylococcus aureus infections in New Zealand is among the highest reported in the developed world. Using nationally collated hospital discharge data, we analyzed the epidemiology of serious S. aureus infections in New Zealand during 2000-2011. During this period, incidence of S. aureus skin and soft tissue infections increased significantly while incidence of staphylococcal sepsis and pneumonia remained stable. We observed marked ethnic and sociodemographic inequality across all S. aureus infections; incidence rates for all forms of S. aureus infections were highest among Māori and Pacific Peoples and among patients residing in areas of high socioeconomic deprivation. The increased incidence of S. aureus skin and soft tissue infections, coupled with the demographic disparities, is of considerable concern. Future work should aim to reduce this disturbing national trend.

  5. Staphylococcus aureus antigens and challenges in vaccine development.

    PubMed

    Middleton, John R

    2008-08-01

    Staphylococcus aureus is an important cause of nosocomial and community-acquired infections in humans and animals, as well as mastitis in dairy cattle. Methicillin-resistant S. aureus is increasingly recognized as a cause of staphylococcal infection and, therefore, immunotherapeutics have received new interest in both human and veterinary medicine. Vaccines aimed at preventing S. aureus infection in humans and mastitis in dairy cattle have been studied for many years. While some formulations have shown promise in ameliorating clinical disease, few, if any, of the S. aureus vaccines developed have adequately prevented new infection. The antigens targeted by S. aureus vaccines and potential reasons for the lack of success of vaccination against S. aureus are reviewed in this article.

  6. Nucleotide Accumulation Induced in Staphylococcus aureus by Glycine

    PubMed Central

    Strominger, Jack L.; Birge, Claire H.

    1965-01-01

    Strominger, Jack L. (Washington University School of Medicine, St. Louis, Mo.), and Claire H. Birge. Nucleotide accumulation induced in Staphylococcus aureus by glycine. J. Bacteriol. 89:1124–1127. 1965.—High concentrations of glycine induce accumulation of four uridine nucleotides in Staphylococcus aureus. Investigations of their structure suggest that these compounds are uridine diphosphate (UDP)-acetylmuramic acid, UDP-acetylmuramyl-gly-d-glu-l-lys, UDP-acetylmuramyl-l-ala-d-glu-l-lys and UDP-acetylmuramyl-gly-d-glu-l-lys-d-ala-d-ala. The mechanism by which glycine may induce uridine nucleotide accumulation and protoplast formation is discussed. Images PMID:14276106

  7. Molecular dynamics of Staphylococcus aureus nasal carriage in Hajj pilgrims.

    PubMed

    Verhoeven, P O; Gautret, P; Haddar, C H; Benkouiten, S; Gagnaire, J; Belhouchat, K; Grattard, F; Charrel, R; Pozzetto, B; Drali, T; Lucht, F; Brouqui, P; Memish, Z A; Berthelot, P; Botelho-Nevers, E

    2015-07-01

    During the 2012 Hajj season, the risk of acquisition of Staphylococcus aureus nasal carriage in a cohort of French pilgrims was 22.8%, and was statistically associated with the acquisition of viral respiratory pathogens (p 0.03). The carriage of S. aureus belonging to the emerging clonal complex 398 significantly increased following the pilgrimage (p < 0.05). Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  8. [Comparison of three methods detection of slime production by Staphylococcus aureus and Staphylococcus epidermidis].

    PubMed

    Wróblewska, Joanna; Ciok-Pater, Emilia; Sekowska, Alicja; Gospodarek, Eugenia

    2010-01-01

    In this article, slime production of Staphylococcus aureus and Staphylococcus epidermidis strains from infective skin lesions was evaluated by three different methods: Congo red agar method (CRA), Christensen tube method (CT) and spectrophotometric method (SC). All strains by CT method interpreted as negative (dark-claret or red colonies of the surface). 12 (37.5%) strains of S. aureus, 16 (50.0%) strains of S. epidermidis produced slime as shown by CT method, 6 (18.7%) strains of S. aureus, 8 (25,0%) strains of S. epidermidis by SC method. They also found a correlation of slime production by CT and SC method (p > 0.05).

  9. Genetic Diversity of Staphylococcus aureus in Buruli Ulcer

    PubMed Central

    Amissah, Nana Ama; Glasner, Corinna; Ablordey, Anthony; Tetteh, Caitlin S.; Kotey, Nana Konama; Prah, Isaac; van der Werf, Tjip S.; Rossen, John W.; van Dijl, Jan Maarten; Stienstra, Ymkje

    2015-01-01

    Background Buruli ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans. Previous studies have shown that wounds of BU patients are colonized with M. ulcerans and several other microorganisms, including Staphylococcus aureus, which may interfere with wound healing. The present study was therefore aimed at investigating the diversity and topography of S. aureus colonizing BU patients during treatment. Methodology We investigated the presence, diversity, and spatio-temporal distribution of S. aureus in 30 confirmed BU patients from Ghana during treatment. S. aureus was isolated from nose and wound swabs, and by replica plating of wound dressings collected bi-weekly from patients. S. aureus isolates were characterized by multiple-locus variable number tandem repeat fingerprinting (MLVF) and spa-typing, and antibiotic susceptibility was tested. Principal Findings Nineteen (63%) of the 30 BU patients tested positive for S. aureus at least once during the sampling period, yielding 407 S. aureus isolates. Detailed analysis of 91 isolates grouped these isolates into 13 MLVF clusters and 13 spa-types. Five (26%) S. aureus-positive BU patients carried the same S. aureus genotype in their anterior nares and wounds. S. aureus isolates from the wounds of seven (37%) patients were distributed over two different MLVF clusters. Wounds of three (16%) patients were colonized with isolates belonging to two different genotypes at the same time, and five (26%) patients were colonized with different S. aureus types over time. Five (17%) of the 30 included BU patients tested positive for methicillin-resistant S. aureus (MRSA). Conclusion/Significance The present study showed that the wounds of many BU patients were contaminated with S. aureus, and that many BU patients from the different communities carried the same S. aureus genotype during treatment. This calls for improved wound care and hygiene. PMID:25658641

  10. Staphylococcus aureus Shifts toward Commensalism in Response to Corynebacterium Species.

    PubMed

    Ramsey, Matthew M; Freire, Marcelo O; Gabrilska, Rebecca A; Rumbaugh, Kendra P; Lemon, Katherine P

    2016-01-01

    Staphylococcus aureus-human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe-microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr) system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence toward a commensal state when exposed to commensal Corynebacterium species.

  11. Twelve aberrant strains of Staphylococcus aureus subsp. aureus from clinical specimens.

    PubMed Central

    Fontana, C; Cellini, L; Dainelli, B

    1993-01-01

    A new biovar of Staphylococcus aureus subsp. aureus was isolated from human clinical specimens and described on the basis of studies of 12 isolates that were compared with 11 standard reference strains. Both DNA hybridization experiments and numerical taxonomy analysis demonstrated that these strains were strictly related to S. aureus subsp. aureus; however, they were significantly different from the latter. The atypical strains belonging to the new biovar can be distinguished from typical S. aureus subsp. aureus strains by their alpha-chymotrypsin, alpha-glucosidase, beta-N-acetylglucosaminidase, lipase (C-14), and leucine arylamidase enzymatic activities and novobiocin resistance. Thus, the combination of alpha-glucosidase and beta-N-acetyl-glucosaminidase is more useful for distinguishing these S. aureus strains from the other, typical ones. PMID:8370737

  12. Comparison of bactericidal activities of various disinfectants against methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.

    PubMed

    Yasuda, T; Yoshimura, S; Katsuno, Y; Takada, H; Ito, M; Takahashi, M; Yahazaki, F; Iriyama, J; Ishigo, S; Asano, Y

    1993-01-01

    Various disinfectants were compared in terms of the duration of bactericidal activity against methicillin-sensitive Staphylococcus aureus (MSSA), and methicillin-resistant Staphylococcus aureus (MRSA), among S. aureus isolated in our hospital. Strains of S. aureus which showed minimum inhibitory concentrations of cloxacillin of less than 1.56 micrograms/ml and of 3.13 micrograms/ml or higher were designated MSSA and MRSA respectively. There was no difference in sensitivity to disinfectants between MSSA and MRSA. There was a great variation in the duration of bactericidal activity of chlorhexidine gluconate against these species with the majority requiring contact times of between 2 minutes and over 20 minutes. All strains except for one strain of MRSA were killed within 20 seconds after disinfection with benzalkonium chloride. All strains were killed within 20 seconds after disinfection with alkyldiaminoethylglycine hydrochloride or povidone-iodine.

  13. An emerging superbug. Staphylococcus aureus becomes less susceptible to vancomycin.

    PubMed

    Brown, J W; Grilli, A

    1998-01-01

    The name staphylococcus aureus comes from the Greek, staphyle (a bunch of grapes), kokkos (berry shaped), and aureus (golden). Morphologically, the pathogen resembles grapelike clusters of gram-positive cocci. The illustration here shows the bacteria infecting nasal epithelial tissue, and causing cell damage and inflammation. S. aureus has been knocking down our antibiotic defenses one by one, with some strains becoming dangerously less susceptible to vancomycin. Epidemiologists warn that these strains are coming soon to a hospital near you; be prepared by knowing how to identify the bug, notify infection control authorities, and use basic infection control procedures.

  14. Structural and functional characterization of Staphylococcus aureus dihydrodipicolinate synthase.

    PubMed

    Girish, Tavarekere S; Sharma, Eshita; Gopal, B

    2008-08-20

    Lysine biosynthesis is crucial for cell-wall formation in bacteria. Enzymes involved in lysine biosynthesis are thus potential targets for anti-microbial therapeutics. Dihydrodipicolinate synthase (DHDPS) catalyzes the first step of this pathway. Unlike its homologues, Staphylococcus aureus DHDPS is a dimer both in solution and in the crystal and is not feedback inhibited by lysine. The crystal structure of S. aureus DHDPS in the free and substrate bound forms provides a structural rationale for its catalytic mechanism. The structure also reveals unique conformational features of the S. aureus enzyme that could be crucial for the design of specific non-competitive inhibitors.

  15. The Staphylococcus aureus RNome and Its Commitment to Virulence

    PubMed Central

    Felden, Brice; Vandenesch, François; Bouloc, Philippe; Romby, Pascale

    2011-01-01

    Staphylococcus aureus is a major human pathogen causing a wide spectrum of nosocomial and community-associated infections with high morbidity and mortality. S. aureus generates a large number of virulence factors whose timing and expression levels are precisely tuned by regulatory proteins and RNAs. The aptitude of bacteria to use RNAs to rapidly modify gene expression, including virulence factors in response to stress or environmental changes, and to survive in a host is an evolving concept. Here, we focus on the recently inventoried S. aureus regulatory RNAs, with emphasis on those with identified functions, two of which are directly involved in pathogenicity. PMID:21423670

  16. Prevention and treatment of Staphylococcus aureus biofilms

    PubMed Central

    Bhattacharya, Mohini; Wozniak, Daniel J; Stoodley, Paul; Hall-Stoodley, Luanne

    2016-01-01

    S. aureus colonizes both artificial and tissue surfaces in humans causing chronic persistent infections that are difficult to cure. It is a notorious pathogen due to its antibiotic recalcitrance and phenotypic adaptability, both of which are facilitated by its ability to develop biofilms. S. aureus biofilms challenge conventional anti-infective approaches, most notably antibiotic therapy. Therefore there is an unmet need to develop and include parallel approaches that target S. aureus biofilm infections. This review discusses two broad anti-infective strategies: (1) preventative approaches (anti-biofilm surface coatings, the inclusion of biofilm-specific vaccine antigens); and (2) approaches aimed at eradicating established S. aureus biofilms, particularly those associated with implant infections. Advances in understanding the distinct nature of S. aureus biofilm development and pathogenesis have led to growing optimism in S. aureus biofilm targeted anti-infective strategies. Further research is needed however, to see the successful administration and validation of these approaches to the diverse types of infections caused by S. aureus biofilms from multiple clinical strains. PMID:26646248

  17. Protease production by Staphylococcus epidermidis and its effect on Staphylococcus aureus biofilms.

    PubMed

    Vandecandelaere, Ilse; Depuydt, Pieter; Nelis, Hans J; Coenye, Tom

    2014-04-01

    Due to the resistance of Staphylococcus aureus to several antibiotics, treatment of S. aureus infections is often difficult. As an alternative to conventional antibiotics, the field of bacterial interference is investigated. Staphylococcus epidermidis produces a serine protease (Esp) which inhibits S. aureus biofilm formation and which degrades S. aureus biofilms. In this study, we investigated the protease production of 114 S. epidermidis isolates, obtained from biofilms on endotracheal tubes (ET). Most of the S. epidermidis isolates secreted a mixture of serine, cysteine and metalloproteases. We found a link between high protease production by S. epidermidis and the absence of S. aureus in ET biofilms obtained from the same patient. Treating S. aureus biofilms with the supernatant (SN) of the most active protease producing S. epidermidis isolates resulted in a significant biomass decrease compared to untreated controls, while the number of metabolically active cells was not affected. The effect on the biofilm biomass was mainly due to serine proteases. Staphylococcus aureus biofilms treated with the SN of protease producing S. epidermidis were thinner with almost no extracellular matrix. An increased survival of Caenorhabditis elegans, infected with S. aureus Mu50, was observed when the SN of protease positive S. epidermidis was added. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  18. Quantitation of Staphylococcus aureus in seawater using CHROMagar SA.

    PubMed

    Tice, Alan D; Pombo, David; Hui, Jennifer; Kurano, Michelle; Bankowski, Matthew J; Seifried, Steven E

    2010-01-01

    A microbiological algorithm has been developed to analyze beach water samples for the determination of viable colony forming units (CFU) of Staphylococcus aureus (S. aureus). Membrane filtration enumeration of S. aureus from recreational beach waters using the chromogenic media CHROMagar SA alone yields a positive predictive value (PPV) of 70%. Presumptive CHROMagar SA colonies were confirmed as S. aureus by 24-hour tube coagulase test. Combined, these two tests yield a PPV of 100%. This algorithm enables accurate quantitation of S. aureus in seawater in 72 hours and could support risk-prediction processes for recreational waters. A more rapid protocol, utilizing a 4-hour tube coagulase confirmatory test, enables a 48-hour turnaround time with a modest false negative rate of less than 10%.

  19. Host-pathogen interactions between the skin and Staphylococcus aureus.

    PubMed

    Krishna, Sheila; Miller, Lloyd S

    2012-02-01

    Staphylococcus aureus is responsible for the vast majority of bacterial skin infections in humans. The propensity for S. aureus to infect skin involves a balance between cutaneous immune defense mechanisms and virulence factors of the pathogen. The tissue architecture of the skin is different from other epithelia especially since it possesses a corneal layer, which is an important barrier that protects against the pathogenic microorganisms in the environment. The skin surface, epidermis, and dermis all contribute to host defense against S. aureus. Conversely, S. aureus utilizes various mechanisms to evade these host defenses to promote colonization and infection of the skin. This review will focus on host-pathogen interactions at the skin interface during the pathogenesis of S. aureus colonization and infection.

  20. Gastrointestinal Dissemination and Transmission of Staphylococcus aureus following Bacteremia

    PubMed Central

    Kernbauer, Elisabeth; Maurer, Katie; Torres, Victor J.

    2014-01-01

    Mutations that alter virulence and antibiotic susceptibility arise and persist during Staphylococcus aureus bacteremia. However, an experimental system demonstrating transmission following bacteremia has been lacking, and thus implications of within-host adaptation for between-host transmission are unknown. We report that S. aureus disseminates to the gastrointestinal tract of mice following intravenous injection and readily transmits to cohoused naive mice. Both intestinal dissemination and transmission were linked to the production of virulence factors based on gene deletion studies of the sae and agr two-component systems. Furthermore, antimicrobial selection for antibiotic-resistant S. aureus displaced susceptible S. aureus from the intestine of infected hosts, which led to the preferential transmission and dominance of antibiotic-resistant bacteria among cohoused untreated mice. These findings establish an animal model to investigate gastrointestinal dissemination and transmission of S. aureus and suggest that adaptation during the course of systemic infection has implications beyond the level of a single host. PMID:25385792

  1. Impact of Staphylococcus aureus on Pathogenesis in Polymicrobial Infections

    PubMed Central

    Nair, Nisha; Biswas, Raja; Götz, Friedrich

    2014-01-01

    Polymicrobial infections involving Staphylococcus aureus exhibit enhanced disease severity and morbidity. We reviewed the nature of polymicrobial interactions between S. aureus and other bacterial, fungal, and viral cocolonizers. Microbes that were frequently recovered from the infection site with S. aureus are Haemophilus influenzae, Enterococcus faecalis, Pseudomonas aeruginosa, Streptococcus pneumoniae, Corynebacterium sp., Lactobacillus sp., Candida albicans, and influenza virus. Detailed analyses of several in vitro and in vivo observations demonstrate that S. aureus exhibits cooperative relations with C. albicans, E. faecalis, H. influenzae, and influenza virus and competitive relations with P. aeruginosa, Streptococcus pneumoniae, Lactobacillus sp., and Corynebacterium sp. Interactions of both types influence changes in S. aureus that alter its characteristics in terms of colony formation, protein expression, pathogenicity, and antibiotic susceptibility. PMID:24643542

  2. Staphylococcus aureus vs. Osteoblast: Relationship and Consequences in Osteomyelitis

    PubMed Central

    Josse, Jérôme; Velard, Frédéric; Gangloff, Sophie C.

    2015-01-01

    Bone cells, namely osteoblasts and osteoclasts work in concert and are responsible for bone extracellular matrix formation and resorption. This homeostasis is, in part, altered during infections by Staphylococcus aureus through the induction of various responses from the osteoblasts. This includes the over-production of chemokines, cytokines and growth factors, thus suggesting a role for these cells in both innate and adaptive immunity. S. aureus decreases the activity and viability of osteoblasts, by induction of apoptosis-dependent and independent mechanisms. The tight relationship between osteoclasts and osteoblasts is also modulated by S. aureus infection. The present review provides a survey of the relevant literature discussing the important aspects of S. aureus and osteoblast interaction as well as the ability for antimicrobial peptides to kill intra-osteoblastic S. aureus, hence emphasizing the necessity for new anti-infectious therapeutics. PMID:26636047

  3. Mild Staphylococcus aureus Skin Infection Improves the Course of Subsequent Endogenous S. aureus Bacteremia in Mice.

    PubMed

    van den Berg, Sanne; de Vogel, Corné P; van Belkum, Alex; Bakker-Woudenberg, Irma A J M

    2015-01-01

    Staphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and evaluate protection in relation to anti-staphylococcal antibody levels. Skin infections once or twice by a clinical S. aureus isolate (isolate P) or S. aureus strain 8325-4 were induced in mice free of S. aureus and anti-staphylococcal antibodies. Five weeks later, immunoglobulin G (IgG) levels in blood against 25 S. aureus antigens were determined, and LD50 or LD100 bacteremia caused by S. aureus isolate P was induced. S. aureus skin infections led to elevated levels of anti-staphylococcal IgG in blood. One skin infection improved the course of subsequent severe endogenous bacteremia only. A second skin infection further improved animal survival rate, which was associated with increased pre-bacteremia IgG levels against Efb, IsaA, LukD, LukE, Nuc, PrsA and WTA. In conclusion, S. aureus isolate P skin infection in mice reduces the severity of subsequent endogenous S. aureus bacteremia only. Although cellular immune effects cannot be rules out, anti-staphylococcal IgG against specified antigens may contribute to this effect.

  4. Mild Staphylococcus aureus Skin Infection Improves the Course of Subsequent Endogenous S. aureus Bacteremia in Mice

    PubMed Central

    van den Berg, Sanne; de Vogel, Corné P.; van Belkum, Alex; Bakker-Woudenberg, Irma A. J. M.

    2015-01-01

    Staphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and evaluate protection in relation to anti-staphylococcal antibody levels. Skin infections once or twice by a clinical S. aureus isolate (isolate P) or S. aureus strain 8325-4 were induced in mice free of S. aureus and anti-staphylococcal antibodies. Five weeks later, immunoglobulin G (IgG) levels in blood against 25 S. aureus antigens were determined, and LD50 or LD100 bacteremia caused by S. aureus isolate P was induced. S. aureus skin infections led to elevated levels of anti-staphylococcal IgG in blood. One skin infection improved the course of subsequent severe endogenous bacteremia only. A second skin infection further improved animal survival rate, which was associated with increased pre-bacteremia IgG levels against Efb, IsaA, LukD, LukE, Nuc, PrsA and WTA. In conclusion, S. aureus isolate P skin infection in mice reduces the severity of subsequent endogenous S. aureus bacteremia only. Although cellular immune effects cannot be rules out, anti-staphylococcal IgG against specified antigens may contribute to this effect. PMID:26060995

  5. Staphylococcus aureus Shifts toward Commensalism in Response to Corynebacterium Species

    PubMed Central

    Ramsey, Matthew M.; Freire, Marcelo O.; Gabrilska, Rebecca A.; Rumbaugh, Kendra P.; Lemon, Katherine P.

    2016-01-01

    Staphylococcus aureus–human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe–microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr) system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence toward a commensal state when exposed to commensal Corynebacterium species. PMID:27582729

  6. Staphylococcus aureus bacteriuria as a prognosticator for outcome of Staphylococcus aureus bacteremia: a case-control study

    PubMed Central

    2010-01-01

    Background When Staphylococcus aureus is isolated in urine, it is thought to usually represent hematogenous spread. Because such spread might have special clinical significance, we evaluated predictors and outcomes of S. aureus bacteriuria among patients with S. aureus bacteremia. Methods A case-control study was performed at John H. Stroger Jr. Hospital of Cook County among adult inpatients during January 2002-December 2006. Cases and controls had positive and negative urine cultures, respectively, for S. aureus, within 72 hours of positive blood culture for S. aureus. Controls were sampled randomly in a 1:4 ratio. Univariate and multivariable logistic regression analyses were done. Results Overall, 59% of patients were African-American, 12% died, 56% of infections had community-onset infections, and 58% were infected with methicillin-susceptible S. aureus (MSSA). Among 61 cases and 247 controls, predictors of S. aureus bacteriuria on multivariate analysis were urological surgery (OR = 3.4, p = 0.06) and genitourinary infection (OR = 9.2, p = 0.002). Among patients who died, there were significantly more patients with bacteriuria than among patients who survived (39% vs. 17%; p = 0.002). In multiple Cox regression analysis, death risks in bacteremic patients were bacteriuria (hazard ratio 2.9, CI 1.4-5.9, p = 0.004), bladder catheter use (2.0, 1.0-4.0, p = 0.06), and Charlson score (1.1, 1.1-1.3, p = 0.02). Neither length of stay nor methicillin-resistant Staphylococcus aureus (MRSA) infection was a predictor of S. aureus bacteriuria or death. Conclusions Among patients with S. aureus bacteremia, those with S. aureus bacteriuria had 3-fold higher mortality than those without bacteriuria, even after adjustment for comorbidities. Bacteriuria may identify patients with more severe bacteremia, who are at risk of worse outcomes. PMID:20667139

  7. Staphylococcus aureus ST398, New York City and Dominican Republic

    PubMed Central

    Bhat, Meera; Dumortier, Caroline; Taylor, Barbara S.; Miller, Maureen; Vasquez, Glenny; Yunen, Jose; Brudney, Karen; Rodriguez-Taveras, Carlos; Rojas, Rita; Leon, Patricia

    2009-01-01

    Closely related Staphylococcus aureus strains of ST398, an animal-associated strain, were identified in samples collected from humans in northern Manhattan, New York, NY, USA, and in the Dominican Republic. A large population in northern Manhattan has close ties to the Dominican Republic, suggesting international transmission. PMID:19193274

  8. An Interdisciplinary Experiment: Azo-Dye Metabolism by "Staphylococcus Aureus"

    ERIC Educational Resources Information Center

    Brocklesby, Kayleigh; Smith, Robert; Sharp, Duncan

    2012-01-01

    An interdisciplinary and engaging practical is detailed which offers great versatility in the study of a qualitative and quantitative metabolism of azo-dyes by "Staphylococcus aureus". This practical has broad scope for adaptation in the number and depth of variables to allow a focused practical experiment or small research project. Azo-dyes are…

  9. Methicillin‐resistant Staphylococcus aureus and the media.

    PubMed

    Perencevich, Eli N; Treise, Debbie M

    2010-11-01

    How the media communicate and how the scientific community influences the media are important factors to consider in the public health response to emerging pathogens, including methicillin-resistant Staphylococcus aureus. Social representation theory suggests that the media link "the threatening" to commonplace "anchor representations" which can serve to educate or to create fear.

  10. Community-acquired Methicillin-resistant Staphylococcus aureus, Uruguay

    PubMed Central

    Ma, Xiao Xue; Galiana, Antonio; Pedreira, Walter; Mowszowicz, Martin; Christophersen, Inés; Machiavello, Silvia; Lope, Liliana; Benaderet, Sara; Buela, Fernanda; Vicentino, Walter; Albini, María; Bertaux, Olivier; Constenla, Irene; Bagnulo, Homero; Llosa, Luis; Ito, Teruyo

    2005-01-01

    A novel, methicillin-resistant Staphylococcus aureus clone (Uruguay clone) with a non–multidrug-resistant phenotype caused a large outbreak, including 7 deaths, in Montevideo, Uruguay. The clone was distinct from the highly virulent community clone represented by strain MW2, although both clones carried Panton-Valentine leukocidin gene and cna gene. PMID:15963301

  11. USA300 Methicillin-resistant Staphylococcus aureus in Cuba

    PubMed Central

    2012-01-01

    Background Methicillin-resistant Staphylococcus aureus is an increasing problem in the Caribbean. We investigated the molecular epidemiology of MRSA isolates on Cuba. Findings The predominant clone was of the spa type t149, followed by community-associated MRSA USA300. Conclusions We report the first molecular typing results of MRSA isolates from Cuba. PMID:22958408

  12. Novel pleuromutilin derivatives with excellent antibacterial activity against Staphylococcus aureus.

    PubMed

    Xu, Peng; Zhang, Yuan-Yuan; Sun, Yong-Xue; Liu, Jian-Hua; Yang, Bing; Wang, Yu-Zhong; Wang, Yu-Liang

    2009-06-01

    Ten novel pleuromutilin derivatives with thioether moiety and heterocyclic carboxamide or chloroformate group in the side chain were synthesized and confirmed by (1)H NMR, IR and HRMS. The results of the antibacterial activity showed that the title compounds had excellent antibacterial activity against Staphylococcus aureus, among which the MIC of 5f reached 0.03125 microg/mL.

  13. Microstructures as IR-sensors with Staphylococcus aureus bacteria

    NASA Astrophysics Data System (ADS)

    Baikova, T. V.; Danilov, P. A.; Gonchukov, S. A.; Yermachenko, V. M.; Ionin, A. A.; Khmelnitskii, R. A.; Kudryashov, S. I.; Nguyen, T. T. H.; Rudenko, A. A.; Saraeva, I. N.; Svistunova, T. S.; Zayarny, D. A.

    2017-09-01

    Using a micro-hole grating in a supported silver film as a laser-fabricated novel optical platform for surface-enhanced IR absoprtion/reflection spectroscopy, characteristic absorption bands of Staphylococcus aureus, especially - its buried carotenoid fragments - were detected in FT-IR spectra with 10-fold analytical enhancement, paving the way to spectral express-identification of the pathogenic microorganisms.

  14. Genome Sequence of Bacterial Interference Strain Staphylococcus aureus 502A.

    PubMed

    Parker, Dane; Narechania, Apurva; Sebra, Robert; Deikus, Gintaras; Larussa, Samuel; Ryan, Chanelle; Smith, Hannah; Prince, Alice; Mathema, Barun; Ratner, Adam J; Kreiswirth, Barry; Planet, Paul J

    2014-04-10

    Staphylococcus aureus 502A was a strain used in bacterial interference programs during the 1960s and early 1970s. Infants were deliberately colonized with 502A with the goal of preventing colonization with more invasive strains. We present the completed genome sequence of this organism.

  15. Review on Panton Valentine leukocidin toxin carriage among Staphylococcus aureus.

    PubMed

    Shrestha, B

    2013-09-01

    Panton Valentine leukocidin is a toxin making pores in the polymorphonuclear cells which is a virulence factor of some strains of Staphylococcus aureus. Initially it was produced by methicillin susceptible Staphylococcus aureus only. Later with the acquisition of mecA gene has lead it to be PVL positive methicillin resistant Staphylococcus aureus. Since MRSA are resistant to many antibiotics and further they produce a toxin the infections by PVL positive MRSA has become a challenge. PVL positive MRSA a virulent strain of drug resistant superbug MRSA that has spread around the world, has claimed many lives in UK, Europe, USA and Australia. Some strains of superbug attack the healthy young people and kill within 24 hrs. PVL positive Staphylococcus aureus has been reported to be associated with skin and soft tissue infections however they also cause invasive infections and necrotizing pneumonia. These microorganisms known to be community associated have spread to hospitals. Hospital acquired infection by such microorganisms lead to an increase in mortality hence should be controlled before they become prevalent in hospitals.

  16. Pulsed-field gel electrophoresis typing of Staphylococcus aureus isolates

    USDA-ARS?s Scientific Manuscript database

    Pulsed-field gel electrophoresis (PFGE) is the most applied and effective genetic typing method for epidemiological studies and investigation of foodborne outbreaks caused by different pathogens, including Staphylococcus aureus. The technique relies on analysis of large DNA fragments generated by th...

  17. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3700...

  18. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3700...

  19. An Interdisciplinary Experiment: Azo-Dye Metabolism by "Staphylococcus Aureus"

    ERIC Educational Resources Information Center

    Brocklesby, Kayleigh; Smith, Robert; Sharp, Duncan

    2012-01-01

    An interdisciplinary and engaging practical is detailed which offers great versatility in the study of a qualitative and quantitative metabolism of azo-dyes by "Staphylococcus aureus". This practical has broad scope for adaptation in the number and depth of variables to allow a focused practical experiment or small research project. Azo-dyes are…

  20. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Staphylococcus Aureus Bacterin-Toxoid. 113.115 Section 113.115 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE..., each weighing 2000-3000 grams, shall be used as test animals. Either a five rabbit individual serum...

  1. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Staphylococcus Aureus Bacterin-Toxoid. 113.115 Section 113.115 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE..., each weighing 2000-3000 grams, shall be used as test animals. Either a five rabbit individual serum...

  2. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Staphylococcus Aureus Bacterin-Toxoid. 113.115 Section 113.115 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE..., each weighing 2000-3000 grams, shall be used as test animals. Either a five rabbit individual serum...

  3. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Staphylococcus Aureus Bacterin-Toxoid. 113.115 Section 113.115 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE..., each weighing 2000-3000 grams, shall be used as test animals. Either a five rabbit individual serum...

  4. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... gut and causes destruction of the intestinal lining (gastroenteritis). (b) Classification. Class I...

  5. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... gut and causes destruction of the intestinal lining (gastroenteritis). (b) Classification. Class I...

  6. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... gut and causes destruction of the intestinal lining (gastroenteritis). (b) Classification. Class I...

  7. [Recovery of Staphylococcus aureus after acid damage].

    PubMed

    Assis, E M; de Carvalho, E P; Asquieri, E R; da Silva, F V; Robbs, P G

    1995-01-01

    The growth behavior of S. aureus in fresh cheese (Minas and Mozzarella) during their shelf life was studied in this research. The possibility of injury to this microorganism caused by increasing acidity was also investigated. Raw milk was inoculated with S. aureus FRIA-100 with approximately 10(6) cells/ml and cheese production was carried out according to normal procedures. They were stored at 7 degrees C during 40 days for Minas cheese and during 60 days for Mozzarella cheese. At 2 to 3 days intervals the following analyses were performed: acidity, pH, S. aureus count on Baird-Parker agar by traditional methods and by the method recommended by the American Public Health Association, to count repair of injured cells. We were certain of the presence of injured S. aureus when acidity was in the range of 0.7 to 0.8% expressed as lactic acid and when the count was 1.3 log higher.

  8. Discrimination of Staphylococcus aureus strains from different species of Staphylococcus using Fourier transform infrared (FTIR) spectroscopy.

    PubMed

    Lamprell, H; Mazerolles, G; Kodjo, A; Chamba, J F; Noël, Y; Beuvier, E

    2006-04-15

    Staphylococcus aureus is a widespread opportunistic pathogen that can cause food-borne illness and is sometimes associated with raw milk and raw milk cheese products. The traditional taxonomic procedures for classification of staphylococcal species are time consuming and often several tests are required. FTIR spectroscopy offers a rapid method for the discrimination and identification of S. aureus strains isolated from raw milk and raw milk cheeses. FTIR spectroscopy was used to discriminate S. aureus from other species of Staphylococcus. This was achieved by using a model composed of 39 species and subspecies of Staphylococcus. The model was validated using a set of spectra of strains isolated from raw milk and different varieties of French raw milk cheese. S. aureus was successfully discriminated from the other species of Staphylococcus and all the strains of S. aureus isolated from raw milk and different varieties of French raw milk cheese were also successfully identified as such. These results demonstrated that FTIR spectroscopy is a rapid (results obtained within 24 h starting from a pure strain or a single colony) and robust method for the identification of S. aureus isolates of dairy origin and food-borne origin in general.

  9. Facing antibiotic resistance: Staphylococcus aureus phages as a medical tool.

    PubMed

    Kaźmierczak, Zuzanna; Górski, Andrzej; Dąbrowska, Krystyna

    2014-07-01

    Staphylococcus aureus is a common and often virulent pathogen in humans. This bacterium is widespread, being present on the skin and in the nose of healthy people. Staphylococcus aureus can cause infections with severe outcomes ranging from pustules to sepsis and death. The introduction of antibiotics led to a general belief that the problem of bacterial infections would be solved. Nonetheless, pathogens including staphylococci have evolved mechanisms of drug resistance. Among current attempts to address this problem, phage therapy offers a promising alternative to combat staphylococcal infections. Here, we present an overview of current knowledge on staphylococcal infections and bacteriophages able to kill Staphylococcus, including experimental studies and available data on their clinical use.

  10. Facing Antibiotic Resistance: Staphylococcus aureus Phages as a Medical Tool

    PubMed Central

    Kaźmierczak, Zuzanna; Górski, Andrzej; Dąbrowska, Krystyna

    2014-01-01

    Staphylococcus aureus is a common and often virulent pathogen in humans. This bacterium is widespread, being present on the skin and in the nose of healthy people. Staphylococcus aureus can cause infections with severe outcomes ranging from pustules to sepsis and death. The introduction of antibiotics led to a general belief that the problem of bacterial infections would be solved. Nonetheless, pathogens including staphylococci have evolved mechanisms of drug resistance. Among current attempts to address this problem, phage therapy offers a promising alternative to combat staphylococcal infections. Here, we present an overview of current knowledge on staphylococcal infections and bacteriophages able to kill Staphylococcus, including experimental studies and available data on their clinical use. PMID:24988520

  11. Staphylococcus aureus Induces Increased Serine Protease Activity in Keratinocytes.

    PubMed

    Williams, Michael R; Nakatsuji, Teruaki; Sanford, James A; Vrbanac, Alison F; Gallo, Richard L

    2017-02-01

    Bacteria that reside on the skin can influence the behavior of the cutaneous immune system, but the mechanisms responsible for these effects are incompletely understood. Colonization of the skin by Staphylococcus aureus (S. aureus) is increased in atopic dermatitis and can result in increased severity of the disease. In this study, we show that S. aureus stimulates human keratinocytes to increase their endogenous protease activity, including specific increases in trypsin activity. This increased protease activity coincided with increased expression of mRNA for kallikreins (KLKs), with KLK6, 13, and 14 showing the greatest induction after exposure to S. aureus. Suppression of mRNA for these KLKs in keratinocytes by targeted small interfering RNA silencing before S. aureus exposure blocked the increase in protease activity. Keratinocytes exposed to S. aureus showed enhanced degradation of desmoglein-1 and filaggrin, whereas small interfering RNA for KLK6, KLK13, and KLK14 partially blocked this degradation. These data illustrate how S. aureus directly influences the skin barrier integrity by stimulating endogenous proteolytic activity and defines a previously unknown mechanism by which S. aureus may influence skin diseases. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Staphylococcus aureus strategies to evade the host acquired immune response.

    PubMed

    Goldmann, Oliver; Medina, Eva

    2017-09-15

    Staphylococcus aureus poses a significant public-health problem. Infection caused by S. aureus can manifest as acute or long-lasting persistent diseases that are often refractory to antibiotic and are associated with significant morbidity and mortality. To develop more effective strategies for preventing or treating these infections, it is crucial to understand why the immune response is incapable to eradicate the bacterium. When S. aureus first infect the host, there is a robust activation of the host innate immune responses. Generally, S. aureus can survive this initial interaction due to the expression of a wide array of virulence factors that interfere with the host innate immune defenses. After this initial interaction the acquired immune response is the arm of the host defenses that will try to clear the pathogen. However, S. aureus is capable of maintaining infection in the host even in the presence of a robust antigen-specific immune response. Thus, understanding the mechanisms underlying the ability of S. aureus to escape immune surveillance by the acquired immune response will help uncover potentially important targets for the development of immune-based adjunctive therapies and more efficient vaccines. There are several lines of evidence that lead us to believe that S. aureus can directly or indirectly disable the acquired immune response. This review will discuss the different immune evasion strategies used by S. aureus to modulate the different components of the acquired immune defenses. Copyright © 2017 Elsevier GmbH. All rights reserved.

  13. Activity of novel inhibitors of Staphylococcus aureus biofilms.

    PubMed

    Woo, Seung-Gyun; Lee, So-Yeon; Lee, So-Min; Lim, Kyoung-Hee; Ha, Eun-Ju; Eom, Yong-Bin

    2017-03-01

    Staphylococcus aureus is one of the most important pathogens causing chronic biofilm infections. These are becoming more difficult to treat owing to drug resistance, particularly because S. aureus biofilms limit the efficacy of antimicrobial agents, leading to high morbidity and mortality. In the present study, we screened for inhibitors of S. aureus biofilm formation using a natural product library from the Korea Chemical Bank (KCB). Screening by crystal violet-based biomass staining assay identified hit compounds. Further examination of antibiofilm properties of these compounds was conducted and led to the identification of celastrol and telithromycin. In vitro, both celastrol and telithromycin were toxic to planktonic S. aureus and also active against a clinical methicillin-resistant S. aureus (MRSA) isolate. The effect of the compounds on preformed biofilms of clinical MRSA isolates was evaluated by confocal laser scanning microscopy (CLSM), which revealed the absence of typical biofilm architecture. In addition, celastrol and telithromycin inhibited the production of extracellular protein at selected sub-MIC concentrations, which revealed the reduced extracellular polymeric substance (EPS) secretion. Celastrol exhibited greater cytotoxicity than telithromycin. These data suggest that the hit compounds, especially telithromycin, could be considered novel inhibitors of S. aureus biofilm. Although the mechanisms of the effects on S. aureus biofilms are not fully understood, our data suggest that telithromycin could be a useful adjuvant therapeutic agent for S. aureus biofilm-related infections.

  14. Knowledge gaps and research priorities in Staphylococcus aureus mastitis control.

    PubMed

    Rainard, P; Foucras, G; Fitzgerald, J R; Watts, J L; Koop, G; Middleton, J R

    2017-10-06

    This study assessed knowledge gaps and suggested research priorities in the field of Staphylococcus aureus mastitis. Staphylococcus aureus infecting the mammary gland remains a major problem to the dairy industry worldwide because of its pathogenicity, contagiousness, persistence in the cow environment, colonization of skin or mucosal epithelia, and the poor curing efficacy of treatments. Staphylococcus aureus also constitutes a threat to public health due to food safety and antibiotic usage issues and the potential for bidirectional transmission of strains between humans and dairy animals (cows and small ruminants). Gaps have been identified in (i) understanding the molecular basis for pathogenesis of S. aureus mastitis, (ii) identifying staphylococcal antigens inducing protection and (iii) determining the cell-mediated immune responses to infection and vaccination. The recommended priorities for research are (i) improved diagnostic methods for early detection of infection and intervention through treatment or management, (ii) development of experimental models to investigate the strategies used by S. aureus to survive within the mammary gland and resist treatment with anti-microbials, (iii) investigation of the basis for cow-to-cow variation in response to S. aureus mastitis, (iv) identification of the immune responses (adaptive and innate) induced by infection or vaccination and (v) antibacterial discovery programmes to develop new, more effective, narrow spectrum antibacterial agents for the treatment of S. aureus mastitis. With the availability and ongoing improvement of molecular research tools, these objectives may not be out of reach in the future. © 2017 Blackwell Verlag GmbH.

  15. Staphylococcus aureus reservoirs during traditional Austrian raw milk cheese production.

    PubMed

    Walcher, Georg; Gonano, Monika; Kümmel, Judith; Barker, Gary C; Lebl, Karin; Bereuter, Othmar; Ehling-Schulz, Monika; Wagner, Martin; Stessl, Beatrix

    2014-11-01

    Sampling approaches following the dairy chain, including microbiological hygiene status of critical processing steps and physicochemical parameters, contribute to our understanding of how Staphylococcus aureus contamination risks can be minimised. Such a sampling approach was adopted in this study, together with rapid culture-independent quantification of Staph. aureus to supplement standard microbiological methods. A regional cheese production chain, involving 18 farms, was sampled on two separate occasions. Overall, 51·4% of bulk milk samples were found to be Staph. aureus positive, most of them (34·3%) at the limit of culture-based detection. Staph. aureus positive samples >100 cfu/ml were recorded in 17·1% of bulk milk samples collected mainly during the sampling in November. A higher number of Staph. aureus positive bulk milk samples (94·3%) were detected after applying the culture-independent approach. A concentration effect of Staph. aureus was observed during curd processing. Staph. aureus were not consistently detectable with cultural methods during the late ripening phase, but >100 Staph. aureus cell equivalents (CE)/ml or g were quantifiable by the culture-independent approach until the end of ripening. Enterotoxin gene PCR and pulsed-field gel electrophoresis (PFGE) typing provided evidence that livestock adapted strains of Staph. aureus mostly dominate the post processing level and substantiates the belief that animal hygiene plays a pivotal role in minimising the risk of Staph. aureus associated contamination in cheese making. Therefore, the actual data strongly support the need for additional sampling activities and recording of physicochemical parameters during semi-hard cheese-making and cheese ripening, to estimate the risk of Staph. aureus contamination before consumption.

  16. Dysbiosis and Staphylococcus aureus colonization drives inflammation in atopic dermatitis

    PubMed Central

    Kobayashi, Tetsuro; Glatz, Martin; Horiuchi, Keisuke; Kawasaki, Hiroshi; Akiyama, Haruhiko; Kaplan, Daniel H.; Kong, Heidi H.; Amagai, Masayuki; Nagao, Keisuke

    2015-01-01

    Summary Staphylococcus aureus skin colonization is universal in atopic dermatitis and common in cancer patients treated with epidermal growth factor receptor inhibitors. However, the causal relationship of dysbiosis and eczema has yet to be clarified. Herein, we demonstrate that Adam17fl/flSox9-Cre mice, generated to model ADAM17-deficiency in human, developed eczematous dermatitis with naturally occurring dysbiosis, similar to that observed in atopic dermatitis. Corynebacterium mastitidis, S. aureus, and Corynebacterium bovis sequentially emerged during the onset of eczematous dermatitis, and antibiotic specific for these bacterial species almost completely reversed dysbiosis and eliminated skin inflammation. Whereas S. aureus prominently drove eczema formation, C. bovis induced robust T helper 2 cell responses. Langerhans cells were required for eliciting immune responses against S. aureus inoculation. These results characterize differential contributions of dysbiotic flora during eczema formation, and highlight the microbiota-host immunity axis as a possible target for future therapeutics in eczematous dermatitis. PMID:25902485

  17. New epidemiology of Staphylococcus aureus infection in Africa.

    PubMed

    Schaumburg, F; Alabi, A S; Peters, G; Becker, K

    2014-07-01

    Research on African Staphylococcus aureus has been largely neglected in the past, despite the cultural and geographical diversity in Africa, which has a significant impact on the epidemiology of this pathogen. The polarity between developed urban societies and remote rural populations (e.g. Pygmies), combined with close contact with animals (e.g. livestock and domestic animals, and wildlife), makes the epidemiology of S. aureus on the African continent unique and fascinating. Here, we try to draw an epidemiological picture of S. aureus colonization and infection in Africa, and focus on the wide spread of Panton-Valentine leukocidin-positive isolates, the emergence of the hypervirulent methicillin-resistant S. aureus (MRSA) clone USA300, and the dissemination of the typical African clone MRSA sequence type 88.

  18. Intracellular staphylococcus aureus: Live-in and let die

    PubMed Central

    Fraunholz, Martin; Sinha, Bhanu

    2012-01-01

    Staphylococcus aureus uses a plethora of virulence factors to accommodate a diversity of niches in its human host. Aside from the classical manifestations of S. aureus-induced diseases, the pathogen also invades and survives within mammalian host cells.The survival strategies of the pathogen are as diverse as strains or host cell types used. S. aureus is able to replicate in the phagosome or freely in the cytoplasm of its host cells. It escapes the phagosome of professional and non-professional phagocytes, subverts autophagy, induces cell death mechanisms such as apoptosis and pyronecrosis, and even can induce anti-apoptotic programs in phagocytes. The focus of this review is to present a guide to recent research outlining the variety of intracellular fates of S. aureus. PMID:22919634

  19. Dysbiosis and Staphylococcus aureus Colonization Drives Inflammation in Atopic Dermatitis.

    PubMed

    Kobayashi, Tetsuro; Glatz, Martin; Horiuchi, Keisuke; Kawasaki, Hiroshi; Akiyama, Haruhiko; Kaplan, Daniel H; Kong, Heidi H; Amagai, Masayuki; Nagao, Keisuke

    2015-04-21

    Staphylococcus aureus skin colonization is universal in atopic dermatitis and common in cancer patients treated with epidermal growth factor receptor inhibitors. However, the causal relationship of dysbiosis and eczema has yet to be clarified. Herein, we demonstrate that Adam17(fl/fl)Sox9-(Cre) mice, generated to model ADAM17-deficiency in human, developed eczematous dermatitis with naturally occurring dysbiosis, similar to that observed in atopic dermatitis. Corynebacterium mastitidis, S. aureus, and Corynebacterium bovis sequentially emerged during the onset of eczematous dermatitis, and antibiotics specific for these bacterial species almost completely reversed dysbiosis and eliminated skin inflammation. Whereas S. aureus prominently drove eczema formation, C. bovis induced robust T helper 2 cell responses. Langerhans cells were required for eliciting immune responses against S. aureus inoculation. These results characterize differential contributions of dysbiotic flora during eczema formation, and highlight the microbiota-host immunity axis as a possible target for future therapeutics in eczematous dermatitis.

  20. Wall teichoic acids mediate increased virulence in Staphylococcus aureus.

    PubMed

    Wanner, Stefanie; Schade, Jessica; Keinhörster, Daniela; Weller, Nicola; George, Shilpa E; Kull, Larissa; Bauer, Jochen; Grau, Timo; Winstel, Volker; Stoy, Henriette; Kretschmer, Dorothee; Kolata, Julia; Wolz, Christiane; Bröker, Barbara M; Weidenmaier, Christopher

    2017-01-23

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) are the cause of a severe pandemic consisting primarily of skin and soft tissue infections. The underlying pathomechanisms have not been fully understood and we report here a mechanism that plays an important role for the elevated virulence of CA-MRSA. Surprisingly, skin abscess induction in an animal model was correlated with the amount of a major cell wall component of S. aureus, termed wall teichoic acid (WTA). CA-MRSA exhibited increased cell-wall-associated WTA content (WTA(high)) and thus were more active in inducing abscess formation via a WTA-dependent and T-cell-mediated mechanism than S. aureus strains with a WTA(low) phenotype. We show here that WTA is directly involved in S. aureus strain-specific virulence and provide insight into the underlying molecular mechanisms that could guide the development of novel anti-infective strategies.

  1. Environmental Staphylococcus aureus contamination in a Tunisian hospital.

    PubMed

    Gharsa, Haythem; Dziri, Raoudha; Klibi, Naouel; Chairat, Sarra; Lozano, Carmen; Torres, Carmen; Bellaaj, Ridha; Slama, Karim Ben

    2016-12-01

    One hundred hospital environment samples were obtained in 2012 in a Tunisian hospital and tested for Staphylococcus aureus recovery. Antimicrobial resistance profile and virulence gene content were determined. Multilocus-sequence-typing (MLST), spa-typing, agr-typing and SmaI-pulsed-field gel electrophoresis (PFGE) were performed. Two methicillin-resistant S. aureus (MRSA) isolates typed as: ST247-t052-SCCmecI-agrI were recovered from the intensive care unit (ICU). Ten samples contained methicillin-susceptible S. aureus (MSSA) and these samples were collected in different services, highlighting the presence of the tst gene encoding the toxic shock syndrome toxin as well as the lukED, hla, hlb, hld and hlgv virulence genes in some of the isolates. In conclusion, we have shown that the hospital environment could be a reservoir contributing to dissemination of virulent S. aureus and MRSA.

  2. Staphylococcus aureus in Antarctica: carriage and attempted eradication.

    PubMed Central

    Krikler, S. J.

    1986-01-01

    The carriage of Staphylococcus aureus was studied in a group of 28 men living in a totally isolated environment for a year. Initially, nasal, axillary and perineal swabs were taken at weekly intervals, but from week 24 throat swabs were taken from known nasal carriers. Several attempts were made during the study to eradicate S. aureus. Eight subjects consistently carried their own phage type throughout the study, despite the application of antibacterial agents. In three subjects strains were isolated late in the study of a phage type which had either not been isolated before in this study, or had not been found for a prolonged period. Nine of the 12 nasal carriers also yielded S. aureus from the throat. It is apparent that following attempted eradication, S. aureus may seem to disappear, only to reappear some time later; 'eradication' in this case would be an erroneous appellation. PMID:3794322

  3. [Recovery of Staphylococcus aureus after acid injury in milk products].

    PubMed

    Assis, E M; De Carvalho, E P; Asquieri, E R; Robbs, P G

    1994-01-01

    The growth behavior of Staphylococcus aureus in fresh Cheese (Minas and Muzzarella) during their shelf-life was studied. The possible injury of this microorganism caused by the increasing acidity was also investigated. Raw milk was inoculated with 10(6) cells/ml (S. aureus FRIA-100) and the cheese production was performed according to normal procedures. Minas and muzzarella cheese were stored at 7 degrees C for 40 and 60 days, respectively. At 2-3 days intervals, the following analysis were performed: acidity, pH, S. aureus counting using agar Baird Parker by the traditional methods and by the method recommended by the American Public Health Association to evaluate the reparation of injured cells. We had a secure indication of the presence of injured S. aureus when acidity was in the range of 0.7 to 0.8% expressed in lactic acid and when the cycle was 1.3 log higher than the traditional one.

  4. Monoclonal Antibody Targeting Staphylococcus aureus Surface Protein A (SasA) Protect Against Staphylococcus aureus Sepsis and Peritonitis in Mice.

    PubMed

    Yang, Yilong; Qian, Mengying; Yi, Shaoqiong; Liu, Shuling; Li, Bing; Yu, Rui; Guo, Qiang; Zhang, Xiaopeng; Yu, Changming; Li, Jianmin; Xu, Junjie; Chen, Wei

    2016-01-01

    Epidemic methicillin-resistant Staphylococcus aureus (MRSA) imposes an increasing impact on public health. Due to multi-antibiotics resistance in MRSA strains, there is an urgent need to develop novel therapeutics such as effective monoclonal antibodies (mAbs) against MRSA infections. Staphylococcus aureus surface protein A (SasA), a large surface-located protein (~240 kDa), is one of MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) and a potential target for immunotherapeutic approaches against S. aureus infections. In the present study, we analyzed the sequence of SasA with bioinformatics tools and generated a protective monoclonal antibody (2H7) targeting the conserved domain of SasA. 2H7 was shown to recognize wild-type S. aureus and promote opsonophagocytic killing of S. aureus. In both sepsis and peritoneal infection models, prophylactic administration of 2H7 improved the survival of BALB/c mice challenged by S. aureus strain USA300 and ST239 (prevalent MRSA clones in North America and Asian countries, respectively) and enhanced bacterial clearance in kidneys. Additionally, 2H7 prophylaxis prevented the formation of intraperitoneal abscess in a murine model of peritoneal infection and therapeutic administration of 2H7 showed protective efficacy in a murine sepsis model. Our results presented here provide supporting evidences that an anti-SasA mAb might be a potential component in an antibody-based immunotherapeutic treatment of MRSA infections.

  5. Monoclonal Antibody Targeting Staphylococcus aureus Surface Protein A (SasA) Protect Against Staphylococcus aureus Sepsis and Peritonitis in Mice

    PubMed Central

    Yang, Yilong; Qian, Mengying; Yi, Shaoqiong; Liu, Shuling; Li, Bing; Yu, Rui; Guo, Qiang; Zhang, Xiaopeng; Yu, Changming; Li, Jianmin; Xu, Junjie; Chen, Wei

    2016-01-01

    Epidemic methicillin-resistant Staphylococcus aureus (MRSA) imposes an increasing impact on public health. Due to multi-antibiotics resistance in MRSA strains, there is an urgent need to develop novel therapeutics such as effective monoclonal antibodies (mAbs) against MRSA infections. Staphylococcus aureus surface protein A (SasA), a large surface-located protein (~240 kDa), is one of MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) and a potential target for immunotherapeutic approaches against S. aureus infections. In the present study, we analyzed the sequence of SasA with bioinformatics tools and generated a protective monoclonal antibody (2H7) targeting the conserved domain of SasA. 2H7 was shown to recognize wild-type S. aureus and promote opsonophagocytic killing of S. aureus. In both sepsis and peritoneal infection models, prophylactic administration of 2H7 improved the survival of BALB/c mice challenged by S. aureus strain USA300 and ST239 (prevalent MRSA clones in North America and Asian countries, respectively) and enhanced bacterial clearance in kidneys. Additionally, 2H7 prophylaxis prevented the formation of intraperitoneal abscess in a murine model of peritoneal infection and therapeutic administration of 2H7 showed protective efficacy in a murine sepsis model. Our results presented here provide supporting evidences that an anti-SasA mAb might be a potential component in an antibody-based immunotherapeutic treatment of MRSA infections. PMID:26926145

  6. Differentiation between Staphylococcus aureus and Staphylococcus epidermidis strains using Raman spectroscopy.

    PubMed

    Rebrošová, Katarína; Šiler, Martin; Samek, Ota; Růžička, Filip; Bernatová, Silvie; Ježek, Jan; Zemánek, Pavel; Holá, Veronika

    2017-08-01

    Raman spectroscopy is an analytical method with a broad range of applications across multiple scientific fields. We report on a possibility to differentiate between two important Gram-positive species commonly found in clinical material - Staphylococcus aureus and Staphylococcus epidermidis - using this rapid noninvasive technique. For this, we tested 87 strains, 41 of S. aureus and 46 of S. epidermidis, directly from colonies grown on a Mueller-Hinton agar plate using Raman spectroscopy. The method paves a way for separation of these two species even on high number of samples and therefore, it can be potentially used in clinical diagnostics.

  7. Effect of proteases against biofilms of Staphylococcus aureus and Staphylococcus epidermidis.

    PubMed

    Elchinger, P-H; Delattre, C; Faure, S; Roy, O; Badel, S; Bernardi, T; Taillefumier, C; Michaud, P

    2014-11-01

    Biofilms play a key role in bacterial resistance against antibacterial agents-an issue that causes multiple problems in medical fields, particularly with Staphylococcus biofilms that colonize medical indwelling devices. The literature reports several anti-biofilm strategies that have been applied in medicine. Disrupting the biofilm formation process creates new sites open to colonization by treatment-generated planktonic bacteria, so efforts have turned to focus on strategies to prevent and control the initial Staphylococci adhesion. Here, we investigated the preventive activities of three commercial proteases (Flavourzyme, Neutrase and Alcalase) against biofilm formation by two Staphylococcus strains. Some proteolytic extracts revealed interesting results with Staphylococcus epidermidis and Staphylococcus aureus aureus biofilms. Three proteases were tested against Staphylococcus aureus and Staphylococcus epidermidis biofilms in standard conditions. The Flavourzyme containing a mix of Aspergillus orizae endo- and exoproteases demonstrated significant efficacy against Staph. epidermidis biofilm formation. These results could prove valuable in the effort to develop simple anti-biofilm methods. © 2014 The Society for Applied Microbiology.

  8. Salicylic acid enhances Staphylococcus aureus extracellular adhesin protein expression.

    PubMed

    Alvarez, Lucía P; Barbagelata, María S; Cheung, Ambrose L; Sordelli, Daniel O; Buzzola, Fernanda R

    2011-11-01

    One of the virulence factors required by Staphylococcus aureus at the early stages of infection is Eap, a secreted adhesin that binds many host proteins and is upregulated by the two-component regulatory system saeRS. The S. aureus Newman strain harbors a mutation in saeS that is thought to be responsible for the high level of Eap expression in this strain. This study was designed to ascertain whether salicylic acid (SAL) affects the expression of Eap and the internalization of S. aureus into epithelial cells. The strain Newman treated with SAL exhibited increased levels of eap transcription and protein expression. Furthermore, SAL treatment increased the eap promoter activity. SAL treatment enhanced Eap expression in the Newman and in other S. aureus strains that do not carry the mutation in saeS. Internalization of S. aureus eap and sae mutants into the MAC-T epithelial cells was significantly decreased compared with the wild-type counterparts. In conclusion, we demonstrated that a low concentration of SAL increased S. aureus Eap expression possibly due to enhancement of sae. SAL may create the conditions for S. aureus persistence in the host, not only by decreasing the capsular polysaccharide expression as shown before, but also by enhancing Eap expression.

  9. Metabolic sensor governing bacterial virulence in Staphylococcus aureus.

    PubMed

    Ding, Yue; Liu, Xing; Chen, Feifei; Di, Hongxia; Xu, Bin; Zhou, Lu; Deng, Xin; Wu, Min; Yang, Cai-Guang; Lan, Lefu

    2014-11-18

    An effective metabolism is essential to all living organisms, including the important human pathogen Staphylococcus aureus. To establish successful infection, S. aureus must scavenge nutrients and coordinate its metabolism for proliferation. Meanwhile, it also must produce an array of virulence factors to interfere with host defenses. However, the ways in which S. aureus ties its metabolic state to its virulence regulation remain largely unknown. Here we show that citrate, the first intermediate of the tricarboxylic acid (TCA) cycle, binds to and activates the catabolite control protein E (CcpE) of S. aureus. Using structural and site-directed mutagenesis studies, we demonstrate that two arginine residues (Arg145 and Arg256) within the putative inducer-binding cavity of CcpE are important for its allosteric activation by citrate. Microarray analysis reveals that CcpE tunes the expression of 126 genes that comprise about 4.7% of the S. aureus genome. Intriguingly, although CcpE is a major positive regulator of the TCA-cycle activity, its regulon consists predominantly of genes involved in the pathogenesis of S. aureus. Moreover, inactivation of CcpE results in increased staphyloxanthin production, improved ability to acquire iron, increased resistance to whole-blood-mediated killing, and enhanced bacterial virulence in a mouse model of systemic infection. This study reveals CcpE as an important metabolic sensor that allows S. aureus to sense and adjust its metabolic state and subsequently to coordinate the expression of virulence factors and bacterial virulence.

  10. [Eradication of Staphylococcus aureus in carrier patients undergoing joint arthroplasty].

    PubMed

    Barbero Allende, José M; Romanyk Cabrera, Juan; Montero Ruiz, Eduardo; Vallés Purroy, Alfonso; Melgar Molero, Virginia; Agudo López, Rosa; Gete García, Luis; López Álvarez, Joaquín

    2015-02-01

    Prosthetic joint infection (PJI) is a complication with serious repercussions and its main cause is Staphylococcus aureus. The purpose of this study is to determine whether decolonization of S.aureus carriers helps to reduce the incidence of PJI by S.aureus. An S.aureus screening test was performed on nasal carriers in patients undergoing knee or hip arthroplasty between January and December 2011. Patients with a positive test were treated with intranasal mupirocin and chlorhexidine soap 5 days. The incidence of PJI was compared with patients undergoing the same surgery between January and December 2010. A total of 393 joint replacements were performed in 391 patients from the control group, with 416 joint replacements being performed in the intervention group. Colonization study was performed in 382 patients (91.8%), of which 102 were positive (26.7%) and treated. There was 2 PJI due S.aureus compared with 9 in the control group (0.5% vs 2.3%, odds ratio [OR]: 0.2, 95% confidence interval [CI]: 0.4 to 2.3, P=.04). In our study, the detection of colonization and eradication of S.aureus carriers achieved a significant decrease in PJI due to S.aureus compared to a historical group. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  11. Global antibody response to Staphylococcus aureus live-cell vaccination.

    PubMed

    Selle, Martina; Hertlein, Tobias; Oesterreich, Babett; Klemm, Theresa; Kloppot, Peggy; Müller, Elke; Ehricht, Ralf; Stentzel, Sebastian; Bröker, Barbara M; Engelmann, Susanne; Ohlsen, Knut

    2016-04-22

    The pathogen Staphylococcus aureus causes a broad range of severe diseases and is feared for its ability to rapidly develop resistance to antibiotic substances. The increasing number of highly resistant S. aureus infections has accelerated the search for alternative treatment options to close the widening gap in anti-S. aureus therapy. This study analyses the humoral immune response to vaccination of Balb/c mice with sublethal doses of live S. aureus. The elicited antibody pattern in the sera of intravenously and intramuscularly vaccinated mice was determined using of a recently developed protein array. We observed a specific antibody response against a broad set of S. aureus antigens which was stronger following i.v. than i.m. vaccination. Intravenous but not intramuscular vaccination protected mice against an intramuscular challenge infection with a high bacterial dose. Vaccine protection was correlated with the strength of the anti-S. aureus antibody response. This study identified novel vaccine candidates by using protein microarrays as an effective tool and showed that successful vaccination against S. aureus relies on the optimal route of administration.

  12. Global antibody response to Staphylococcus aureus live-cell vaccination

    PubMed Central

    Selle, Martina; Hertlein, Tobias; Oesterreich, Babett; Klemm, Theresa; Kloppot, Peggy; Müller, Elke; Ehricht, Ralf; Stentzel, Sebastian; Bröker, Barbara M.; Engelmann, Susanne; Ohlsen, Knut

    2016-01-01

    The pathogen Staphylococcus aureus causes a broad range of severe diseases and is feared for its ability to rapidly develop resistance to antibiotic substances. The increasing number of highly resistant S. aureus infections has accelerated the search for alternative treatment options to close the widening gap in anti-S. aureus therapy. This study analyses the humoral immune response to vaccination of Balb/c mice with sublethal doses of live S. aureus. The elicited antibody pattern in the sera of intravenously and intramuscularly vaccinated mice was determined using of a recently developed protein array. We observed a specific antibody response against a broad set of S. aureus antigens which was stronger following i.v. than i.m. vaccination. Intravenous but not intramuscular vaccination protected mice against an intramuscular challenge infection with a high bacterial dose. Vaccine protection was correlated with the strength of the anti-S. aureus antibody response. This study identified novel vaccine candidates by using protein microarrays as an effective tool and showed that successful vaccination against S. aureus relies on the optimal route of administration. PMID:27103319

  13. Molecular typing of antibiotic-resistant Staphylococcus aureus in Nigeria.

    PubMed

    O'Malley, S M; Emele, F E; Nwaokorie, F O; Idika, N; Umeizudike, A K; Emeka-Nwabunnia, I; Hanson, B M; Nair, R; Wardyn, S E; Smith, T C

    2015-01-01

    Antibiotic-resistant Staphylococcus aureus including methicillin-resistant strains (MRSA) are a major concern in densely populated urban areas. Initial studies of S. aureus in Nigeria indicated existence of antibiotic-resistant S. aureus strains in clinical and community settings. 73 biological samples (40 throat, 23 nasal, 10 wound) were collected from patients and healthcare workers in three populations in Nigeria: Lagos University Teaching Hospital, Nigerian Institute of Medical Research, and Owerri General Hospital. S. aureus was isolated from 38 of 73 samples (52%). Of the 38 S. aureus samples, 9 (24%) carried the Panton-Valentine leukocidin gene (PVL) while 16 (42%) possessed methicillin resistance genes (mecA). Antibiotic susceptibility profiles indicated resistance to several broad-spectrum antibiotics. Antibiotic-resistant S. aureus isolates were recovered from clinical and community settings in Nigeria. Insight about S. aureus in Nigeria may be used to improve antibiotic prescription methods and minimize the spread of antibiotic-resistant organisms in highly populated urban communities similar to Lagos, Nigeria. Copyright © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  14. Epic Immune Battles of History: Neutrophils vs. Staphylococcus aureus

    PubMed Central

    Guerra, Fermin E.; Borgogna, Timothy R.; Patel, Delisha M.; Sward, Eli W.; Voyich, Jovanka M.

    2017-01-01

    Neutrophils are the most abundant leukocytes in human blood and the first line of defense after bacteria have breached the epithelial barriers. After migration to a site of infection, neutrophils engage and expose invading microorganisms to antimicrobial peptides and proteins, as well as reactive oxygen species, as part of their bactericidal arsenal. Ideally, neutrophils ingest bacteria to prevent damage to surrounding cells and tissues, kill invading microorganisms with antimicrobial mechanisms, undergo programmed cell death to minimize inflammation, and are cleared away by macrophages. Staphylococcus aureus (S. aureus) is a prevalent Gram-positive bacterium that is a common commensal and causes a wide range of diseases from skin infections to endocarditis. Since its discovery, S. aureus has been a formidable neutrophil foe that has challenged the efficacy of this professional assassin. Indeed, proper clearance of S. aureus by neutrophils is essential to positive infection outcome, and S. aureus has developed mechanisms to evade neutrophil killing. Herein, we will review mechanisms used by S. aureus to modulate and evade neutrophil bactericidal mechanisms including priming, activation, chemotaxis, production of reactive oxygen species, and resolution of infection. We will also highlight how S. aureus uses sensory/regulatory systems to tailor production of virulence factors specifically to the triggering signal, e.g., neutrophils and defensins. To conclude, we will provide an overview of therapeutic approaches that may potentially enhance neutrophil antimicrobial functions. PMID:28713774

  15. Staphylococcus aureus infections following knee and hip prosthesis insertion procedures.

    PubMed

    Arduino, Jean Marie; Kaye, Keith S; Reed, Shelby D; Peter, Senaka A; Sexton, Daniel J; Chen, Luke F; Hardy, N Chantelle; Tong, Steven Yc; Smugar, Steven S; Fowler, Vance G; Anderson, Deverick J

    2015-01-01

    Staphylococcus aureus is the most common and most important pathogen following knee and hip arthroplasty procedures. Understanding the epidemiology of invasive S. aureus infections is important to quantify this serious complication. This nested retrospective cohort analysis included adult patients who had undergone insertion of knee or hip prostheses with clean or clean-contaminated wound class at 11 hospitals between 2003-2006. Invasive S. aureus infections, non-superficial incisional surgical site infections (SSIs) and blood stream infections (BSIs), were prospectively identified following each procedure. Prevalence rates, per 100 procedures, were estimated. 13,719 prosthetic knee (62%) and hip (38%) insertion procedures were performed. Of 92 invasive S. aureus infections identified, SSIs were more common (80%) than SSI and BSI (10%) or BSI alone (10%). The rate of invasive S. aureus infection/100 procedures was 0.57 [95% CI: 0.43-0.73] for knee insertion and 0.83 [95% CI: 0.61-1.08] for hip insertion. More than half (53%) were methicillin-resistant. Median time-to-onset of infection was 34 and 26 days for knee and hip insertion, respectively. Infection was associated with higher National Healthcare Safety Network risk index (p ≤ 0.0001). Post-operative invasive S. aureus infections were rare, but difficult-to-treat methicillin-resistant infections were relatively common. Optimizing preventative efforts may greatly reduce the healthcare burden associated with S. aureus infections.

  16. Staphylococcus aureus nasal colonization in HIV outpatients: persistent or transient?

    PubMed

    Padoveze, Maria Clara; de Jesus Pedro, Rogério; Blum-Menezes, Dulcinéa; Bratfich, Orlando José; Moretti, Maria Luiza

    2008-04-01

    Staphylococcus aureus nasal carriage in HIV patients remains incompletely characterized. The aim of the present study was to describe epidemiologic and molecular features of S. aureus nasal colonization in HIV outpatients. HIV outpatients with no history of hospitalization within the previous 2 years were screened for S aureus nasal colonization. Three samples were collected from each patient, and the risk factors for colonization were assessed. Nasal carriage was classified as persistent colonization, transient colonization, or no colonization. Persistent colonization was subdivided into simple (same DNA profile) or multiple (different DNA profiles) using pulsed-field gel electrophoresis (PFGE) for genotyping the strains of S. aureus. A total of 111 patients were evaluated, of which 70 (63.1%) had at least 1 positive culture for S aureus. Patients in clinical stages of AIDS were more likely to be colonized than non-AIDS patients (P = .02). Among the patients with S aureus nasal carriage, 25.2% were transient carriers and 39.4% were persistent carriers. PFGE analysis showed that the persistent colonization was simple in 24 patients and multiple in 17 patients. The HIV patients had a high rate of S. aureus nasal colonization. The most common characteristic of colonization was simple persistent colonization showing the same genomic profile.

  17. Molecular Correlates of Host Specialization in Staphylococcus aureus

    PubMed Central

    Herron-Olson, Lisa; Fitzgerald, J. Ross; Musser, James M.; Kapur, Vivek

    2007-01-01

    Background The majority of Staphylococcus aureus isolates that are recovered from either serious infections in humans or from mastitis in cattle represent genetically distinct sets of clonal groups. Moreover, population genetic analyses have provided strong evidence of host specialization among S. aureus clonal groups associated with human and ruminant infection. However, the molecular basis of host specialization in S. aureus is not understood. Methodology/Principal Findings We sequenced the genome of strain ET3-1, a representative isolate of a common bovine mastitis-causing S. aureus clone. Strain ET3-1 encodes several genomic elements that have not been previously identified in S. aureus, including homologs of virulence factors from other Gram-positive pathogens. Relative to the other sequenced S. aureus associated with human infection, allelic variation in ET3-1 was high among virulence and surface-associated genes involved in host colonization, toxin production, iron metabolism, antibiotic resistance, and gene regulation. Interestingly, a number of well-characterized S. aureus virulence factors, including protein A and clumping factor A, exist as pseudogenes in ET3-1. Whole-genome DNA microarray hybridization revealed considerable similarity in the gene content of highly successful S. aureus clones associated with bovine mastitis, but not among those clones that are only infrequently recovered from bovine hosts. Conclusions/Significance Whole genome sequencing and comparative genomic analyses revealed a set of molecular genetic features that distinguish clones of highly successful bovine-associated S. aureus optimized for mastitis pathogenesis in cattle from those that infect human hosts or are only infrequently recovered from bovine sources. Further, the results suggest that modern bovine specialist clones diverged from a common ancestor resembling human-associated S. aureus clones through a combination of foreign DNA acquisition and gene decay. PMID:17971880

  18. Staphylococcus aureus isolated from tonsillectomized adult patients with recurrent tonsillitis.

    PubMed

    Katkowska, Marta; Garbacz, Katarzyna; Stromkowski, Józef

    2017-01-01

    The aim of this study was to analyze the prevalence and antibiotic resistance of Staphylococcus aureus strains from 118 tonsillectomized adults due to recurrent tonsillitis (RT). The study included strains isolated from the tonsillar surface prior to tonsillectomy, recovered from the tonsillar core at the time of surgery, and from the posterior throat 2-4 weeks after the procedure. Susceptibility of isolates to 19 antibiotics was tested in line with the Clinical and Laboratory Standards Institute recommendations. Irrespective of the stage, the most commonly isolated bacteria were gram-positive cocci, and among them S. aureus. The tonsillar core was the most common site of S. aureus isolation (30.5%), followed by the tonsillar surface (10.8%) and the posterior pharynx (5.9%). This difference turned out to be statistically significant (p < 0.001). Beta-hemolytic streptococci, most often Streptococcus pyogenes (5.1%), were isolated from 2.5% to 10.2% of patients. Staphylococcal isolates were susceptible to most tested antibiotics (except from penicillin and ampicillin) and rarely showed methicillin resistance (n = 1). Staphylococcus aureus seems to be the most common pathogen isolated from patients tonsillectomized due to RT. Staphylococcal isolates associated with RT are present mostly within the tonsillar core and susceptible to most antibiotics. They are typically isolated from patients between 21 and 30 years of age. Tonsillectomy results in less frequent isolation of S. aureus strains.

  19. Is methicillin-resistant Staphylococcus aureus replacing methicillin-susceptible S. aureus?

    PubMed Central

    Mostofsky, Elizabeth; Lipsitch, Marc; Regev-Yochay, Gili

    2011-01-01

    Despite extensive research on the emergence of and treatments for methicillin-resistant Staphylococcus aureus (MRSA), prior studies have not rigorously evaluated the impact of methicillin resistance on the overall incidence of S. aureus infections. Yet, there are direct clinical and research implications of determining whether methicillin-susceptible S. aureus (MSSA) infection rates remain stable in the face of increasing MRSA prevalence or whether MSSA will be replaced over time. A synthesis of prior studies indicates that the emergence of healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) has led to an increase in the overall incidence of S. aureus infections, with MRSA principally adding to, rather than replacing, MSSA. However, colonization with CA-MRSA may at least partially replace colonization with MSSA. So far, evidence indicates that MSSA still accounts for many infections. Therefore, eradication of MRSA alone is not sufficient to address the public health burden of S. aureus. PMID:21737459

  20. Multidrug efflux pumps in Staphylococcus aureus and their clinical implications.

    PubMed

    Jang, Soojin

    2016-01-01

    Antibiotic resistance is rapidly spreading among bacteria such as Staphylococcus aureus, an opportunistic bacterial pathogen that causes a variety of diseases in humans. For the last two decades, bacterial multidrug efflux pumps have drawn attention due to their potential association with clinical multidrug resistance. Numerous researchers have demonstrated efflux-mediated resistance in vitro and in vivo and found novel multidrug transporters using advanced genomic information about bacteria. This article aims to provide a concise summary of multidrug efflux pumps and their important clinical implications, focusing on recent findings concerning S. aureus efflux pumps.

  1. Evaluation of Two New Chromogenic Media, CHROMagar MRSA and S. aureus ID, for Identifying Staphylococcus aureus and Screening Methicillin-Resistant S. aureus

    PubMed Central

    Hedin, Göran; Fang, Hong

    2005-01-01

    Thirty-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates with diverse genetic backgrounds and two reference strains were correctly identified as S. aureus on CHROMagar MRSA and S. aureus ID media. Growth inhibition on CHROMagar MRSA was noted. A combination of cefoxitin disk and S. aureus ID was found suitable for rapid MRSA screening. PMID:16081989

  2. Staphylococcus epidermidis Esp inhibits Staphylococcus aureus biofilm formation and nasal colonization.

    PubMed

    Iwase, Tadayuki; Uehara, Yoshio; Shinji, Hitomi; Tajima, Akiko; Seo, Hiromi; Takada, Koji; Agata, Toshihiko; Mizunoe, Yoshimitsu

    2010-05-20

    Commensal bacteria are known to inhibit pathogen colonization; however, complex host-microbe and microbe-microbe interactions have made it difficult to gain a detailed understanding of the mechanisms involved in the inhibition of colonization. Here we show that the serine protease Esp secreted by a subset of Staphylococcus epidermidis, a commensal bacterium, inhibits biofilm formation and nasal colonization by Staphylococcus aureus, a human pathogen. Epidemiological studies have demonstrated that the presence of Esp-secreting S. epidermidis in the nasal cavities of human volunteers correlates with the absence of S. aureus. Purified Esp inhibits biofilm formation and destroys pre-existing S. aureus biofilms. Furthermore, Esp enhances the susceptibility of S. aureus in biofilms to immune system components. In vivo studies have shown that Esp-secreting S. epidermidis eliminates S. aureus nasal colonization. These findings indicate that Esp hinders S. aureus colonization in vivo through a novel mechanism of bacterial interference, which could lead to the development of novel therapeutics to prevent S. aureus colonization and infection.

  3. Methicillin-resistant Staphylococcus aureus adaptation to human keratinocytes.

    PubMed

    Soong, Grace; Paulino, Franklin; Wachtel, Sarah; Parker, Dane; Wickersham, Matthew; Zhang, Dongni; Brown, Armand; Lauren, Christine; Dowd, Margaret; West, Emily; Horst, Basil; Planet, Paul; Prince, Alice

    2015-04-21

    Skin is the most common site of Staphylococcus aureus infection. While most of these infections are self-limited, recurrent infections are common. Keratinocytes and recruited immune cells participate in skin defense against infection. We postulated that S. aureus is able to adapt to the milieu within human keratinocytes to avoid keratinocyte-mediated clearance. From a collection of S. aureus isolated from chronically infected patients with atopic dermatitis, we noted 22% had an agr mutant-like phenotype. Using several models of human skin infection, we demonstrate that toxin-deficient, agr mutants of methicillin-resistant S. aureus (MRSA) USA300 are able to persist within keratinocytes by stimulating autophagy and evading caspase-1 and inflammasome activation. MRSA infection induced keratinocyte autophagy, as evidenced by galectin-8 and LC3 accumulation. Autophagy promoted the degradation of inflammasome components and facilitated staphylococcal survival. The recovery of more than 58% agr or RNAIII mutants (P < 0.0001) of an inoculum of wild-type (WT) MRSA from within wortmannin-treated keratinocytes compared to control keratinocytes reflected the survival advantage for mutants no longer expressing agr-dependent toxins. Our results illustrate the dynamic interplay between S. aureus and keratinocytes that can result in the selection of mutants that have adapted specifically to evade keratinocyte-mediated clearance mechanisms. Human skin is a major site of staphylococcal infection, and keratinocytes actively participate in eradication of these pathogens. We demonstrate that methicillin-resistant Staphylococcus aureus (MRSA) is ingested by keratinocytes and activates caspase-1-mediated clearance through pyroptosis. Toxin-deficient MRSA mutants are selected within keratinocytes that fail to induce caspase-1 activity and keratinocyte-mediated clearance. These intracellular staphylococci induce autophagy that enhances their intracellular survival by diminishing

  4. Regulatory Requirements for Staphylococcus aureus Nitric Oxide Resistance

    PubMed Central

    Grosser, Melinda R.; Weiss, Andy; Shaw, Lindsey N.

    2016-01-01

    ABSTRACT The ability of Staphylococcus aureus to resist host innate immunity augments the severity and pervasiveness of its pathogenesis. Nitric oxide (NO˙) is an innate immune radical that is critical for the efficient clearance of a wide range of microbial pathogens. Exposure of microbes to NO˙ typically results in growth inhibition and induction of stress regulons. S. aureus, however, induces a metabolic state in response to NO˙ that allows for continued replication and precludes stress regulon induction. The regulatory factors mediating this distinctive response remain largely undefined. Here, we employ a targeted transposon screen and transcriptomics to identify and characterize five regulons essential for NO˙ resistance in S. aureus: three virulence regulons not formerly associated with NO˙ resistance, SarA, CodY, and Rot, as well as two regulons with established roles, Fur and SrrAB. We provide new insights into the contributions of Fur and SrrAB during NO˙ stress and show that the S. aureus ΔsarA mutant, the most sensitive of the newly identified mutants, exhibits metabolic dysfunction and widespread transcriptional dysregulation following NO˙ exposure. Altogether, our results broadly characterize the regulatory requirements for NO˙ resistance in S. aureus and suggest an intriguing overlap between the regulation of NO˙ resistance and virulence in this well-adapted human pathogen. IMPORTANCE The prolific human pathogen Staphylococcus aureus is uniquely capable of resisting the antimicrobial radical nitric oxide (NO˙), a crucial component of the innate immune response. However, a complete understanding of how S. aureus regulates an effective response to NO˙ is lacking. Here, we implicate three central virulence regulators, SarA, CodY, and Rot, as major players in the S. aureus NO˙ response. Additionally, we elaborate on the contribution of two regulators, SrrAB and Fur, already known to play a crucial role in S. aureus NO˙ resistance. Our study

  5. Staphylococcus aureus Central Nervous System Infections in Children.

    PubMed

    Vallejo, Jesus G; Cain, Alexandra N; Mason, Edward O; Kaplan, Sheldon L; Hultén, Kristina G

    2017-10-01

    Central nervous system (CNS) infections caused by Staphylococcus aureus are uncommon in pediatric patients. We review the epidemiology, clinical features and treatment in 68 patients with a S. aureus CNS infection evaluated at Texas Children's Hospital. Cases of CNS infection in children with positive cerebrospinal fluid cultures or spinal epidural abscess (SEA) for S. aureus at Texas Children's Hospital from 2001 to 2013 were reviewed. Seventy cases of S. aureus CNS infection occurred in 68 patients. Forty-nine cases (70%) were secondary to a CNS device, 5 (7.1%) were postoperative meningitis, 9 (12.8%) were hematogenous meningitis and 7 (10%) were SEAs. Forty-seven (67.2%) were caused by methicillin-sensitive S. aureus (MSSA) and 23 (32.8%) by methicillin-resistant S. aureus (MRSA). Community-acquired infections were more often caused by MRSA that was clone USA300/pvl. Most patients were treated with nafcillin (MSSA) or vancomycin (MRSA) with or without rifampin. Among patients with MRSA infection, 50% had a serum vancomycin trough obtained with the median level being 10.6 μg/mL (range: 5.4-15.7 μg/mL). Only 1 death was associated with S. aureus infection. The epidemiology of invasive of S. aureus infections continues to evolve with MSSA accounting for most of the infections in this series. The majority of cases were associated with neurosurgical procedures; however, hematogenous S. aureus meningitis and SEA occurred as community-acquired infections in patients without predisposing factors. Patients with MRSA CNS infections had a favorable response to vancomycin, but the beneficial effect of combination therapy or targeting vancomycin trough concentrations of 15-20 μg/mL remains unclear.

  6. "Gesundheit!" sneezing, common colds, allergies, and Staphylococcus aureus dispersion.

    PubMed

    Bischoff, Werner E; Wallis, Michelle L; Tucker, Brian K; Reboussin, Beth A; Pfaller, Michael A; Hayden, Frederick G; Sherertz, Robert J

    2006-10-15

    Staphylococcus aureus is among the most important pathogens in today's hospital setting. The effects of sneezing on the airborne dispersal of S. aureus and other bacteria were assessed in 11 healthy nasal S. aureus carriers with experimentally induced rhinovirus colds. Airborne dispersal was studied by volumetric air sampling in 2 chamber sessions with and without histamine-induced sneezing. After 2 days of preexposure measurements, volunteers were inoculated with a rhinovirus and monitored for 14 days. Daily quantitative nasal- and skin-culture samples for bacteria and nasal-culture samples for rhinovirus were obtained, cold symptoms were assessed, and volunteer activities were recorded during sessions. All participants developed a cold. Sneezing caused a 4.7-fold increase in the airborne dispersal of S. aureus, a 1.4-fold increase in coagulase-negative staphylococci (CoNS), and a 3.9-fold increase in other bacteria (P < .001). An additional 2.83 colony forming units (cfu) of S. aureus/m3/min, 3.24 cfu of CoNS/m3/min, and 474.61 cfu of other bacteria/m3/min were released per sneeze. Rhinovirus exposure did not change the frequency of sneezing or airborne dispersal. Having respiratory allergies increased the spread of S. aureus by 3.8-fold during sneezing sessions (P < .001). Nasal S. aureus carriers disperse a significant amount of S. aureus into the air by sneezing. Experimental colds do not alter bacterial dispersal, but respiratory allergies multiply the effect of dispersing S. aureus.

  7. Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia

    PubMed Central

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of health care-associated infections. Vancomycin remains an acceptable treatment option. There has been a welcome increase in the number of agents available for the treatment of MRSA infection. These drugs have certain differentiating attributes and may offer some advantages over vancomycin, but they also have significant limitations. These agents provide some alternative when no other options are available. PMID:28032484

  8. Methicillin-resistant Staphylococcus aureus in HIV-infected patients

    PubMed Central

    Hidron, Alicia I; Kempker, Russell; Moanna, Abeer; Rimland, David

    2010-01-01

    Concordant with the emergence of methicillin-resistant Staphylococcus aureus (MRSA) in the community setting, colonization and infections with this pathogen have become a prevalent problem among the human immunodeficiency virus (HIV)-positive population. A variety of different host- and, possibly, pathogen-related factors may play a role in explaining the increased prevalence and incidence observed. In this article, we review pathophysiology, epidemiology, clinical manifestations, and treatment of MRSA in the HIV-infected population. PMID:21694896

  9. High Rates of Staphylococcus aureus USA400 Infection, Northern Canada

    PubMed Central

    Golding, George R.; Levett, Paul N.; McDonald, Ryan R.; Irvine, James; Quinn, Brian; Nsungu, Mandiangu; Woods, Shirley; Khan, Mohammad; Ofner-Agostini, Marianna

    2011-01-01

    Surveillance of Staphylococcus aureus infections in 3 northern remote communities of Saskatchewan was undertaken. Rates of methicillin-resistant infections were extremely high (146–482/10,000 population), and most (98.2%) were caused by USA400 strains. Although USA400 prevalence has diminished in the United States, this strain is continuing to predominate throughout many northern communities in Canada. PMID:21470471

  10. Diversity of Staphylococcus aureus Isolates in European Wildlife.

    PubMed

    Monecke, Stefan; Gavier-Widén, Dolores; Hotzel, Helmut; Peters, Martin; Guenther, Sebastian; Lazaris, Alexandros; Loncaric, Igor; Müller, Elke; Reissig, Annett; Ruppelt-Lorz, Antje; Shore, Anna C; Walter, Birgit; Coleman, David C; Ehricht, Ralf

    2016-01-01

    Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock-associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation.

  11. Diversity of Staphylococcus aureus Isolates in European Wildlife

    PubMed Central

    Monecke, Stefan; Gavier-Widén, Dolores; Hotzel, Helmut; Peters, Martin; Guenther, Sebastian; Lazaris, Alexandros; Loncaric, Igor; Müller, Elke; Reissig, Annett; Ruppelt-Lorz, Antje; Shore, Anna C.; Walter, Birgit; Coleman, David C.; Ehricht, Ralf

    2016-01-01

    Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock-associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation. PMID:27992523

  12. Serological profiles in nursery piglets colonized with Staphylococcus aureus

    PubMed Central

    2013-01-01

    At present, the immune response of pigs in relation to Staphylococcus aureus carriage is poorly understood. This study was aimed at investigating the dynamics of the anti-staphylococcal humoral immune response in methicillin-susceptible S. aureus (MSSA)-positive piglets and at assessing the effect of the experimental introduction of a methicillin-resistant S. aureus (MRSA) Sequence Type (ST) 398 strain. Therefore, serum samples were collected at different times from 31 weaned piglets originating from four different sows. Twenty-four out of the 31 piglets were challenged with MRSA ST398. The serum samples were analyzed for IgG antibodies to 39 S. aureus antigens, using a multiplex bead-based assay (xMAP technology, Luminex Corporation). Though antibody responses showed broad inter-individual variability, serological results appeared to be clustered by litter of origin. For most antigens, an age-related response was observed with an apparent increase in antibody titers directed against staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMM), which have been shown to play a role in S. aureus colonization. In most animals, antibody titers directed against staphylococcal toxins or immune-modulating proteins decreased with age, possibly reflecting the absence of bacterial invasion. The introduction of MRSA ST398 did not elicit a significant humoral immune reaction. This study describes, for the first time, the humoral immune response in weaned pigs colonized with S. aureus. PMID:23339425

  13. Nickel allergy and relationship with Staphylococcus aureus in atopic dermatitis.

    PubMed

    Bogdali, Anna M; Anna, Bogdali M; Grazyna, Antoszczyk; Wojciech, Dyga; Aleksander, Obtulowicz; Anna, Bialecka; Andrzej, Kasprowicz; Zofia, Magnowska; Krystyna, Obtulowicz

    2016-01-01

    The increase of nickel air pollution is supposed to frequent side effects of nickel action related to virulence potential of Staphylococcus aureus in patients with nickel allergy in atopic dermatitis. The goal was to investigate the relationship between nickel allergy and infection by S. aureus in atopic dermatitis. Nickel allergy was confirmed in atopic patients and excluded in healthy volunteers using patch testing. Infection by S. aureus was tested in atopic patients and healthy volunteers by use of API Staph system. The specific IgE for staphylococcal enterotoxin A and B were measured. Secretion of IFN-g, IL-2, IL-13 by PBMC under nickel sulfate and the enterotoxins A and B stimulations were studied with ELISpot. We found the increased number of infections by S. aureus in atopic patients with nickel allergy in comparison to atopic patients and healthy volunteers without nickel allergy. The elevated secretion of IL-2 under nickel sulfate stimulation in vitro was exclusively found in atopic patients with nickel allergy infected by S. aureus. Our data suggest that nickel allergy and infection by S. aureus are linked in atopic dermatitis. Copyright © 2015 Elsevier GmbH. All rights reserved.

  14. Staphylococcus aureus – antimicrobial resistance and the immunocompromised child

    PubMed Central

    McNeil, J Chase

    2014-01-01

    Children with immunocompromising conditions represent a unique group for the acquisition of antimicrobial resistant infections due to their frequent encounters with the health care system, need for empiric antimicrobials, and immune dysfunction. These infections are further complicated in that there is a relative paucity of literature on the clinical features and management of Staphylococcus aureus infections in immunocompromised children. The available literature on the clinical features, antimicrobial susceptibility, and management of S. aureus infections in immunocompromised children is reviewed. S. aureus infections in children with human immunodeficiency virus (HIV) are associated with higher HIV viral loads and a greater degree of CD4 T-cell suppression. In addition, staphylococcal infections in children with HIV often exhibit a multidrug resistant phenotype. Children with cancer have a high rate of S. aureus bacteremia and associated complications. Increased tolerance to antiseptics among staphylococcal isolates from pediatric oncology patients is an emerging area of research. The incidence of S. aureus infections among pediatric solid organ transplant recipients varies considerably by the organ transplanted; in general however, staphylococci figure prominently among infections in the early posttransplant period. Staphylococcal infections are also prominent pathogens among children with a number of immunodeficiencies, notably chronic granulomatous disease. Significant gaps in knowledge exist regarding the epidemiology and management of S. aureus infection in these vulnerable children. PMID:24855381

  15. Colorimetric Detection of Staphylococcus aureus Contaminated Solutions without Purification.

    PubMed

    Tiet, Pamela; Clark, Karen C; McNamara, James O; Berlin, Jacob M

    2017-01-18

    Current water quality monitoring methods rely on growth-based measurements to detect fecal indicator bacteria, such as Escherichia coli and enterococci, and Staphylococcus aureus (S. aureus). These growth-based measurements, however, can take days to complete. This is a significant limitation in the evaluation of contaminated food and water sources. Various methods for selective in vitro detection of S. aureus have also been reported; however, these strategies, such as ELISA, agar-diffusion, PCR, or liquid chromatography-tandem mass spectrometry, all require overnight culturing or sophisticated instrumentation. There is a pressing need for a portable, simple diagnostic for S. aureus. Here, we demonstrate that oligonucleotide-functionalized gold nanoparticles (Oligo-AuNPs) can be designed to rapidly and selectively detect S. aureus with a colorimetric readout. We have functionalized a chemically modified 11-mer sequence onto AuNPs and have found that aggregation occurs in the presence of S. aureus supernantants. The particles can be stored as a lyophilized powder and reconstituted at time of use, and this has been tested in biologically relevant samples such as creek and ocean water. This approach requires minimal sample preparation and requires no extraneous instrumentation, leading to a rapid and simple diagnostic read-out that could be used in field tests to monitor food and water sources.

  16. Exploring the transcriptome of Staphylococcus aureus in its natural niche.

    PubMed

    Chaves-Moreno, Diego; Wos-Oxley, Melissa L; Jáuregui, Ruy; Medina, Eva; Oxley, Andrew Pa; Pieper, Dietmar H

    2016-09-19

    Staphylococcus aureus is an important human pathogen and commensal, where the human nose is the predominant reservoir. To better understand its behavior in this environmental niche, RNA was extracted from the anterior nares of three documented S. aureus carriers and the metatranscriptome analyzed by RNAseq. In addition, the in vivo transcriptomes were compared to previously published transcriptomes of two in vitro grown S. aureus strains. None of the in vitro conditions, even growth in medium resembling the anterior nares environment, mimicked in vivo conditions. Survival in the nose was strongly controlled by the limitation of iron and evident by the expression of iron acquisition systems. S. aureus populations in different individuals clearly experience different environmental stresses, which they attempt to overcome by the expression of compatible solute biosynthetic pathways, changes in their cell wall composition and synthesis of general stress proteins. Moreover, the expression of adhesins was also important for colonization of the anterior nares. However, different S. aureus strains also showed different in vivo behavior. The assessment of general in vivo expression patterns and commonalities between different S. aureus strains will in the future result in new knowledge based strategies for controlling colonization.

  17. Exploring the transcriptome of Staphylococcus aureus in its natural niche

    PubMed Central

    Chaves-Moreno, Diego; Wos-Oxley, Melissa L.; Jáuregui, Ruy; Medina, Eva; Oxley, Andrew PA; Pieper, Dietmar H.

    2016-01-01

    Staphylococcus aureus is an important human pathogen and commensal, where the human nose is the predominant reservoir. To better understand its behavior in this environmental niche, RNA was extracted from the anterior nares of three documented S. aureus carriers and the metatranscriptome analyzed by RNAseq. In addition, the in vivo transcriptomes were compared to previously published transcriptomes of two in vitro grown S. aureus strains. None of the in vitro conditions, even growth in medium resembling the anterior nares environment, mimicked in vivo conditions. Survival in the nose was strongly controlled by the limitation of iron and evident by the expression of iron acquisition systems. S. aureus populations in different individuals clearly experience different environmental stresses, which they attempt to overcome by the expression of compatible solute biosynthetic pathways, changes in their cell wall composition and synthesis of general stress proteins. Moreover, the expression of adhesins was also important for colonization of the anterior nares. However, different S. aureus strains also showed different in vivo behavior. The assessment of general in vivo expression patterns and commonalities between different S. aureus strains will in the future result in new knowledge based strategies for controlling colonization. PMID:27641137

  18. Slime production by Staphylococcus aureus and Staphylococcus epidermidis strains isolated from patients with diabetic foot ulcers.

    PubMed

    Podbielska, Adrianna; Galkowska, Hanna; Stelmach, Ewa; Mlynarczyk, Grazyna; Olszewski, Waldemar L

    2010-08-01

    Slime production is a very important factor related to biofilm formation. The objective of the present study was to determine the frequency of slime production by Staphylococcus aureus and Staphylococcus epidermidis strains recovered from 50 patients with diabetic foot ulcers. Slime production was determined using the Congo red agar (CRA) method and compared with immunocytochemistry for the production of polysaccharide intercellular adhesin (PIA). Out of 55 S. aureus strains, 69% produced slime as shown by the CRA method. Of them, 84.2% also produced PIA. Of 17 CRA-negative strains, 70.6% produced PIA. Out of 20 S. epidermidis strains, 75% were CRA positive and 93.3% produced PIA. All CRA-negative S. epidermidis produced PIA. In conclusion, PIA production is a very common trait of S. aureus and S. epidermidis isolates obtained from diabetic foot ulcer patients.

  19. Antimicrobial susceptibility of Staphylococcus aureus and Staphylococcus pseudintermedius isolated from various animals.

    PubMed

    Rubin, Joseph E; Ball, Katherine R; Chirino-Trejo, Manuel

    2011-02-01

    This study characterized the antimicrobial susceptibility of 221 Staphylococcus aureus isolated from various species, and 60 canine Staphylococcus pseudintermedius isolated from 1986 through 2000 at the Western College of Veterinary Medicine (WCVM). Resistance of S. aureus was most common to penicillin (31%) and tetracycline (14%); resistance of S. pseudintermedius to penicillin was present in 8% and to tetracycline in 34% of isolates. Resistance to trimethoprim/sulfamethoxazole was only seen among S. pseudintermedius, and there was no resistance to amoxicillin/clavulanate, ampicillin/sulbactam, cephalothin, amikacin, gentamicin, enrofloxacin, chloramphenicol, or rifampin among any isolate. Inducible clindamycin resistance was found in both S. aureus and S. pseudintermedius, highlighting the need for careful interpretation of culture and susceptibility test results. There were significant differences in the minimum inhibitory concentrations of penicillin, ciprofloxacin, enrofloxacin, clindamycin, erythromycin, chloramphenicol, and tetracycline between avian, bovine, equine, and porcine isolates.

  20. Contribution of Coagulases towards Staphylococcus aureus Disease and Protective Immunity

    PubMed Central

    Cheng, Alice G.; McAdow, Molly; Kim, Hwan K.; Bae, Taeok; Missiakas, Dominique M.; Schneewind, Olaf

    2010-01-01

    The bacterial pathogen Staphylococcus aureus seeds abscesses in host tissues to replicate at the center of these lesions, protected from host immune cells via a pseudocapsule. Using histochemical staining, we identified prothrombin and fibrin within abscesses and pseudocapsules. S. aureus secretes two clotting factors, coagulase (Coa) and von Willebrand factor binding protein (vWbp). We report here that Coa and vWbp together are required for the formation of abscesses. Coa and vWbp promote the non-proteolytic activation of prothrombin and cleavage of fibrinogen, reactions that are inhibited with specific antibody against each of these molecules. Coa and vWbp specific antibodies confer protection against abscess formation and S. aureus lethal bacteremia, suggesting that coagulases function as protective antigens for a staphylococcal vaccine. PMID:20700445

  1. Staphylococcus aureus biofilms: recent developments in biofilm dispersal

    PubMed Central

    Lister, Jessica L.; Horswill, Alexander R.

    2014-01-01

    Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections. PMID:25566513

  2. Genetically enhanced cows resist intramammary Staphylococcus aureus infection.

    PubMed

    Wall, Robert J; Powell, Anne M; Paape, Max J; Kerr, David E; Bannerman, Douglas D; Pursel, Vernon G; Wells, Kevin D; Talbot, Neil; Hawk, Harold W

    2005-04-01

    Mastitis, the most consequential disease in dairy cattle, costs the US dairy industry billions of dollars annually. To test the feasibility of protecting animals through genetic engineering, transgenic cows secreting lysostaphin at concentrations ranging from 0.9 to 14 micrograms/ml [corrected] in their milk were produced. In vitro assays demonstrated the milk's ability to kill Staphylococcus aureus. Intramammary infusions of S. aureus were administered to three transgenic and ten nontransgenic cows. Increases in milk somatic cells, elevated body temperatures and induced acute phase proteins, each indicative of infection, were observed in all of the nontransgenic cows but in none of the transgenic animals. Protection against S. aureus mastitis appears to be achievable with as little as 3 micrograms/ml [corrected] of lysostaphin in milk. Our results indicate that genetic engineering can provide a viable tool for enhancing resistance to disease and improve the well-being of livestock.

  3. Repurposing the antihistamine terfenadine for antimicrobial activity against Staphylococcus aureus.

    PubMed

    Perlmutter, Jessamyn I; Forbes, Lauren T; Krysan, Damian J; Ebsworth-Mojica, Katherine; Colquhoun, Jennifer M; Wang, Jenna L; Dunman, Paul M; Flaherty, Daniel P

    2014-10-23

    Staphylococcus aureus is a rapidly growing health threat in the U.S., with resistance to several commonly prescribed treatments. A high-throughput screen identified the antihistamine terfenadine to possess, previously unreported, antimicrobial activity against S. aureus and other Gram-positive bacteria. In an effort to repurpose this drug, structure-activity relationship studies yielded 84 terfenadine-based analogues with several modifications providing increased activity versus S. aureus and other bacterial pathogens, including Mycobacterium tuberculosis. Mechanism of action studies revealed these compounds to exert their antibacterial effects, at least in part, through inhibition of the bacterial type II topoisomerases. This scaffold suffers from hERG liabilities which were not remedied through this round of optimization; however, given the overall improvement in activity of the set, terfenadine-based analogues provide a novel structural class of antimicrobial compounds with potential for further characterization as part of the continuing process to meet the current need for new antibiotics.

  4. Repurposing the Antihistamine Terfenadine for Antimicrobial Activity against Staphylococcus aureus

    PubMed Central

    2015-01-01

    Staphylococcus aureus is a rapidly growing health threat in the U.S., with resistance to several commonly prescribed treatments. A high-throughput screen identified the antihistamine terfenadine to possess, previously unreported, antimicrobial activity against S. aureus and other Gram-positive bacteria. In an effort to repurpose this drug, structure–activity relationship studies yielded 84 terfenadine-based analogues with several modifications providing increased activity versus S. aureus and other bacterial pathogens, including Mycobacterium tuberculosis. Mechanism of action studies revealed these compounds to exert their antibacterial effects, at least in part, through inhibition of the bacterial type II topoisomerases. This scaffold suffers from hERG liabilities which were not remedied through this round of optimization; however, given the overall improvement in activity of the set, terfenadine-based analogues provide a novel structural class of antimicrobial compounds with potential for further characterization as part of the continuing process to meet the current need for new antibiotics. PMID:25238555

  5. Superoxide dismutase activity in thermally stressed Staphylococcus aureus.

    PubMed Central

    Bucker, E R; Martin, S E

    1981-01-01

    The effects of heat and NaCl on the activity of superoxide dismutase from Staphylococcus aureus were examined. A linear decrease in superoxide dismutase activity occurred when S. aureus MF-31 cells were thermally stressed for 90 min at 52% C in 100 mM potassium phosphate buffer (pH 7.2). After 20 min of heating, only 5% of the superoxide dismutase activity was lost. Heating for 60, 90 and 120 min resulted in decreases of approximately 10, 22, and 68%, respectively. The rates of thermal inactivation of superoxide dismutase from S. aureus strains 196E and 210 were similar and slightly greater than those of strains MF-31, S-6, and 181. The addition of NaCl before or after heating resulted in increased losses of superoxide dismutase activity. PMID:7235693

  6. Synergistic antibacterial activity of Curcumin with antibiotics against Staphylococcus aureus.

    PubMed

    Teow, Sin-Yeang; Ali, Syed Atif

    2015-11-01

    This study evaluated the synergistic antibacterial activity of Curcumin with 8 different antibiotic groups. Two reference, one clinical and ten environmental strains of Staphylococcus aureus (S. aureus) were tested. Disc diffusion assay with 25 μg/mL Curcumin demonstrated synergism in combination with a majority of tested antibiotics against S. aureus. However, checkerboard micro dilution assay only showed synergism, fractional inhibitory concentration index (FICI) <0.5 in three antibiotics i.e. Gentamicin, Amikacin, and Ciprofloxacin. Other antibiotics showed indifferent interactions but no antagonism was observed. In time-kill curve, appreciable reduction of bacterial cells was also observed in combination therapy (Curcumin + antibiotics) compared to monotherapy (Curcumin or antibiotic(s) alone). The antibiotics with higher synergistic interaction with Curcumin are arranged in a decreasing order: Amikacin > Gentamicin > Ciprofloxacin.

  7. Staphylococcus aureus Peptidoglycan Tertiary Structure from Carbon-13 Spin Diffusion

    PubMed Central

    Sharif, Shasad; Singh, Manmilan; Kim, Sung Joon; Schaefer, Jacob

    2009-01-01

    The cell-wall peptidoglycan of Staphylococcus aureus is a heterogeneous, highly cross-linked polymer of unknown tertiary structure. We have partially characterized this structure by measuring spin diffusion from 13C labels in pentaglycyl cross-linking segments to natural-abundance 13C in the surrounding intact cell walls. The measurements were performed using a version of centerband-only detection of exchange (CODEX). The cell walls were isolated from S. aureus grown in media containing [1-13C]glycine. The CODEX spin diffusion rates established that the pentaglycyl bridge of one peptidoglycan repeat unit of S. aureus is within 5 Å of the glycan chain of another repeat unit. This surprising proximity is interpreted in terms of a model for the peptidoglycan lattice in which all peptide stems in a plane perpendicular to the glycan mainchain are parallel to one another. PMID:19419167

  8. Staphylococcus aureus biofilms: recent developments in biofilm dispersal.

    PubMed

    Lister, Jessica L; Horswill, Alexander R

    2014-01-01

    Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.

  9. Population Structure of Staphylococcus aureus from Trinidad & Tobago

    PubMed Central

    Monecke, Stefan; Stieber, Bettina; Roberts, Rashida; Akpaka, Patrick Eberechi; Slickers, Peter; Ehricht, Ralf

    2014-01-01

    It has been shown previously that high rates of methicillin- and mupirocin-resistant Staphylococcus aureus exist in the Caribbean islands of Trinidad and Tobago, as well as a high prevalence of Panton-Valentine leukocidin-positive S. aureus. Beyond these studies, limited typing data have been published. In order to obtain insight into the population structure not only of MRSA but also of methicillin-susceptible S. aureus, 294 clinical isolates collected in 2012/2013 were typed by microarray hybridisation. A total of 15.31% of the tested isolates were MRSA and 50.00% were PVL-positive. The most common MSSA strains were PVL-positive CC8-MSSA (20.41% of all isolates tested), PVL-positive CC152-MSSA (9.52%) and PVL-positive CC30-MSSA (8.84%) while the most common MRSA were ST239-MRSA-III&SCCmer (9.18%) and ST8-MRSA-IV, “USA300” (5.78%). 2.38% of characterised isolates belonged to distinct strains likely to be related to “Staphylococcus argenteus” lineages. The population structure of S. aureus isolates suggests an importation of strains from Africa, endemicity of PVL-positive MSSA (mainly CC8) and of ST239-MRSA-III, and a recent emergence of the PVL-positive CC8-MRSA-IV strain “USA300”. PMID:24586536

  10. Methicillin-resistant Staphylococcus aureus diagnostics: state of the art.

    PubMed

    Baron, Ellen Jo; Tenover, Fred C

    2012-11-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is among the most common causes of community- and healthcare-acquired infections, accounting for > 80,000 invasive infections in the United States in 2010 according to the Center for Disease Control and Prevention's Active Bacterial Core Surveillance data. Control and treatment of MRSA depend on reliable identification, which is challenging. This article reviews the current status of detection and identification of MRSA. Publications since 2001, guidelines from the Clinical Laboratory Standards Institute and the European Committee on Antimicrobial Susceptibility Testing, common microbiology laboratory practices for identification and characterization of MRSA in human samples, and recent publications that assessed patient care outcomes of various detection and intervention strategies were surveyed for this review. Given the predilection of Staphylococcus aureus to modify its genetic characteristics, thereby enabling the species to stay one step ahead of laboratory detection systems, phenotypic methods for detection of antibiotic resistance mechanisms, especially those directed against the beta-lactam family, will continue to be required, in some situations, for the foreseeable future. Molecular methods are now the gold standard for surveillance, yielding higher sensitivity than the slower, culture-based methods. The newer molecular surveillance methods for detecting methicillin-resistant S. aureus (MRSA) colonization and for rapid and accurate identification of S. aureus from growth in culture systems have revolutionized patient care, enabling rapid interventions that lead to better individual patient outcomes, such as fewer postsurgical site infections, and better overall institutional infection control (fewer healthcare-associated MRSA infections).

  11. Vitamin A deficiency predisposes to Staphylococcus aureus infection.

    PubMed Central

    Wiedermann, U; Tarkowski, A; Bremell, T; Hanson, L A; Kahu, H; Dahlgren, U I

    1996-01-01

    We have investigated the consequences of vitamin A deficiency in a rat model of T-cell-dependent and superantigen-mediated Staphylococcus aureus arthritis. After intravenous inoculation of enterotoxin A-producing staphylococci, the vitamin-A-deficient rats showed a decreased weight gain compared with the paired fed controls despite equal food consumption. The control rats developed arthritis in the first few days after bacterial inoculation, with a peak frequency at day 5, and then gradually recovered; however, the frequency of arthritis 18 days after bacterial inoculation was 86% among the vitamin A-deficient rats and 44% among the control rats. During this period, 3 of 10 deficient rats and 1 of 10 control rats died. Further in vitro analysis revealed that T-cell responses to S. aureus were significantly higher in the vitamin A-deficient rats than in the control animals. In contrast, B-cell reactivity, measured as immunoglobulin levels, autoantibody levels, and specific antibacterial antibody levels in serum, did not differ between the groups. Interestingly, the innate host defense mechanisms against S. aureus were also profoundly affected by vitamin A deficiency. Thus, despite a larger number of circulating phagocytic cells in the vitamin-A-deficient group, the capacity to phagocytize and exert intracellular killing of S. aureus was significantly decreased in comparison with the control rats. Furthermore, serum from the vitamin A-deficient rats inoculated with Staphylococcus aureus displayed decreased complement lysis activity. Our results suggest that the increased susceptibility to S. aureus infection observed in the vitamin-A-deficient rats is due to a concerted action of antigen-specific T-cell hyperactivity, impaired function of the phagocytes, and decreased complement activity. PMID:8557341

  12. Bovine Staphylococcus aureus: Subtyping, evolution, and zoonotic transfer.

    PubMed

    Boss, R; Cosandey, A; Luini, M; Artursson, K; Bardiau, M; Breitenwieser, F; Hehenberger, E; Lam, Th; Mansfeld, M; Michel, A; Mösslacher, G; Naskova, J; Nelson, S; Podpečan, O; Raemy, A; Ryan, E; Salat, O; Zangerl, P; Steiner, A; Graber, H U

    2016-01-01

    Staphylococcus aureus is globally one of the most important pathogens causing contagious mastitis in cattle. Previous studies using ribosomal spacer (RS)-PCR, however, demonstrated in Swiss cows that Staph. aureus isolated from bovine intramammary infections are genetically heterogeneous, with Staph. aureus genotype B (GTB) and GTC being the most prominent genotypes. Furthermore, Staph. aureus GTB was found to be contagious, whereas Staph. aureus GTC and all the remaining genotypes were involved in individual cow disease. In addition to RS-PCR, other methods for subtyping Staph. aureus are known, including spa typing and multilocus sequence typing (MLST). They are based on sequencing the spa and various housekeeping genes, respectively. The aim of the present study was to compare the 3 analytic methods using 456 strains of Staph. aureus isolated from milk of bovine intramammary infections and bulk tanks obtained from 12 European countries. Furthermore, the phylogeny of animal Staph. aureus was inferred and the zoonotic transfer of Staph. aureus between cattle and humans was studied. The analyzed strains could be grouped into 6 genotypic clusters, with CLB, CLC, and CLR being the most prominent ones. Comparing the 3 subtyping methods, RS-PCR showed the highest resolution, followed by spa typing and MLST. We found associations among the methods but in many cases they were unsatisfactory except for CLB and CLC. Cluster CLB was positive for clonal complex (CC)8 in 99% of the cases and typically positive for t2953; it is the cattle-adapted form of CC8. Cluster CLC was always positive for tbl 2645 and typically positive for CC705. For CLR and the remaining subtypes, links among the 3 methods were generally poor. Bovine Staph. aureus is highly clonal and a few clones predominate. Animal Staph. aureus always evolve from human strains, such that every human strain may be the ancestor of a novel animal-adapted strain. The zoonotic transfer of IMI- and milk-associated strains

  13. Innate and adaptive immune responses against Staphylococcus aureus skin infections.

    PubMed

    Krishna, Sheila; Miller, Lloyd S

    2012-03-01

    Staphylococcus aureus is an important human pathogen that is responsible for the vast majority of bacterial skin and soft tissue infections in humans. S. aureus can also become more invasive and cause life-threatening infections such as bacteremia, pneumonia, abscesses of various organs, meningitis, osteomyelitis, endocarditis, and sepsis. These infections represent a major public health threat due to the enormous numbers of these infections and the widespread emergence of methicillin-resistant S. aureus (MRSA) strains. MSRA is endemic in hospitals worldwide and is rapidly spreading throughout the normal human population in the community. The increasing frequency of MRSA infections has complicated treatment as these strains are more virulent and are increasingly becoming resistant to multiple different classes of antibiotics. The important role of the immune response against S. aureus infections cannot be overemphasized as humans with certain genetic and acquired immunodeficiency disorders are at an increased risk for infection. Understanding the cutaneous immune responses against S. aureus is essential as most of these infections occur or originate from a site of infection or colonization of the skin and mucosa. This review will summarize the innate immune responses against S. aureus skin infections, including antimicrobial peptides that have direct antimicrobial activity against S. aureus as well as pattern recognition receptors and proinflammatory cytokines that promote neutrophil abscess formation in the skin, which is required for bacterial clearance. Finally, we will discuss the recent discoveries involving IL-17-mediated responses, which provide a key link between cutaneous innate and adaptive immune responses against S. aureus skin infections.

  14. In vitro and in vivo study of fosfomycin in methicillin-resistant Staphylococcus aureus septicaemia.

    PubMed Central

    Lau, W. Y.; Teoh-Chan, C. H.; Fan, S. T.; Lau, K. F.

    1986-01-01

    Five hundred strains of methicillin-resistant Staphylococcus aureus were tested against various anti-staphylococcal agents. Vancomycin, fusidic acid and fosfomycin were found to be the most effective. Only 1 strain out of 500 was resistant to fosfomycin. Three patients with methicillin-resistant Staphylococcus aureus septicaemia were successfully treated by fosfomycin. We conclude that fosfomycin could be the drug of choice for methicillin-resistant Staphylococcus aureus infection. PMID:3637200

  15. ANTISTAPHYBASE: database of antimicrobial peptides (AMPs) and essential oils (EOs) against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus.

    PubMed

    Zouhir, Abdelmajid; Taieb, Malek; Lamine, Mohamed Ashraf; Cherif, Ammar; Jridi, Taoufik; Mahjoubi, Basma; Mbarek, Sarra; Fliss, Ismail; Nefzi, Adel; Sebei, Khaled; Ben Hamida, Jeannette

    2017-03-01

    Staphylococcus aureus and methicillin-resistant S. aureus are major pathogens. The antimicrobial peptides and essential oils (EOs) display narrow- or broad-spectrum activity against bacteria including these strains. A centralized resource, such as a database, designed specifically for anti-S. aureus/anti-methicillin-resistant S. aureus antimicrobial peptides and EOs is therefore needed to facilitate the comprehensive investigation of their structure/activity associations and combinations. The database ANTISTAPHYBASE is created to facilitate access to important information on antimicrobial peptides and essential peptides against methicillin-resistant S. aureus and S. aureus. At the moment, the database contains 596 sequences of antimicrobial peptides produced by diverse organisms and 287 essential oil records. It permits a quick and easy search of peptides based on their activity as well as their general, physicochemical properties and literature data. These data are very useful to perform further bioinformatic or chemometric analysis and would certainly be useful for the development of new drugs for medical use. The ANTISTAPHYBASE database is freely available at: https://www.antistaphybase.com/ .

  16. Surgical Site Infection by Methicillin Resistant Staphylococcus aureus- on Decline?

    PubMed

    Bhattacharya, Susmita; Pal, Kuhu; Jain, Sonia; Chatterjee, Shiv Sekhar; Konar, Jayashree

    2016-09-01

    Surgical Site Infection (SSI) is the most common healthcare associated infection that could be averted by antibiotics prophylaxis against the probable offending organisms. As Staphylococcus aureus has been playing a substantial role in the aetiology of SSIs, Methicillin Resistant Staphylococcus aureus (MRSA) happens to be a problem while dealing with the postoperative wound infection. To determine the prevalence of SSI caused by MRSA and the antibiotic sensitivity pattern of MRSA. A cross-sectional study was conducted at Nil Ratan Sircar Medical College, Kolkata, West Bengal from July 2009 to December 2012. A total of 19,359 surgical procedures were done of which 3003 culture positive SSIs have been documented. The clinical samples were collected from patients of both sexes and all ages suspected to be suffering from SSI from different specialities. Samples were processed according to CLSI, 2007 guidelines. The isolated strains of Staphylococcus aureus were screened for MRSA by detection of resistance to Cefoxitin disc (zone of inhibition was ≤21 mm) and slidex staph latex agglutination tests were done on cefoxitin resistant strains to spot phenotypic expression of mec A gene. Then PCR was performed for detection of mecA gene. Antibiotic sensitivity test was done following Kirby Bauer technique. In this 3½ year study, 1049 Staphylococcus aureus (34.93%) were reported from 3003 cases of SSI followed by Escherichia coli (20.34%), Klebsiella spp. (18.08%), Pseudomonas spp. (7.99%), Acinetobacter spp. (7.49%) respectively. Among the Staphylococcus aureus, 267 strains were derived as MRSA (25.45%). MRSA were isolated from 167 (62.54%) male patients and 100 (37.45%) female patients having surgical site infections. Inpatients and outpatients distribution of MRSA were 235 (88.01%) and 32 (11.98%) respectively. Majority of the MRSA cases were reported from Surgery (12.49%) and Orthopaedics (11.85%) departments in the age group above 75 years (15.63%). The MRSA strains

  17. Methicillin-resistant Staphylococcus aureus: an overview for manual therapists☆

    PubMed Central

    Green, Bart N.; Johnson, Claire D.; Egan, Jonathon Todd; Rosenthal, Michael; Griffith, Erin A.; Evans, Marion Willard

    2012-01-01

    Objective Methicillin-resistant Staphylococcus aureus (MRSA) is associated with difficult-to-treat infections and high levels of morbidity. Manual practitioners work in environments where MRSA is a common acquired infection. The purpose of this review is to provide a practical overview of MRSA as it applies to the manual therapy professions (eg, physical and occupational therapy, athletic training, chiropractic, osteopathy, massage, sports medicine) and to discuss how to identify and prevent MRSA infections in manual therapy work environments. Methods PubMed and CINAHL were searched from the beginning of their respective indexing years through June 2011 using the search terms MRSA, methicillin-resistant Staphylococcus aureus, and Staphylococcus aureus. Texts and authoritative Web sites were also reviewed. Pertinent articles from the authors' libraries were included if they were not already identified in the literature search. Articles were included if they were applicable to ambulatory health care environments in which manual therapists work or if the content of the article related to the clinical management of MRSA. Results Following information extraction, 95 citations were included in this review, to include 76 peer-reviewed journal articles, 16 government Web sites, and 3 textbooks. Information was organized into 10 clinically relevant categories for presentation. Information was organized into the following clinically relevant categories: microbiology, development of MRSA, risk factors for infection, clinical presentation, diagnostic tests, screening tests, reporting, treatment, prevention for patients and athletes, and prevention for health care workers. Conclusion Methicillin-resistant S aureus is a health risk in the community and to patients and athletes treated by manual therapists. Manual practitioners can play an essential role in recognizing MRSA infections and helping to control its transmission in the health care environment and the community

  18. Burden of Invasive Staphylococcus aureus Infections in Hospitalized Infants

    PubMed Central

    Ericson, Jessica E.; Popoola, Victor O.; Smith, P. Brian; Benjamin, Daniel K.; Fowler, Vance G.; Benjamin, Daniel K.; Clark, Reese H.; Milstone, Aaron M.

    2015-01-01

    Importance Staphylococcus aureus is a frequent cause of infection in hospitalized infants. These infections are associated with increased mortality and morbidity, and longer hospital stays, but data on the burden of S. aureus disease in hospitalized infants are limited. Objective To compare demographics and mortality of infants with invasive methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA), determine the annual proportion of S. aureus infections that were MRSA, and compare the risk of death following an invasive MRSA infection to the risk following an invasive MSSA infection. Design Multicenter retrospective study of a large, nationally representative cohort. Setting 348 neonatal intensive care units managed by the Pediatrix Medical Group. Participants 3888 infants with an invasive S. aureus infection who were discharged between 1997 and 2012. Exposure Invasive S. aureus infection. Main Outcomes and Measures Incidence of invasive S. aureus infections. Infant characteristics and mortality following MRSA or MSSA infection. Results The 3888 infants had 3978 invasive S. aureus infections (2868 MSSA, 1110 MRSA). The incidence of invasive S. aureus infection was 44.8 infections/10,000 infants. The yearly proportion of invasive infections caused by MRSA increased from 1997 to 2006 and has remained relatively stable since then. Infants with invasive MRSA or MSSA infections had similar gestational ages and birth weights. Invasive MRSA infections occurred more often at a younger postnatal age. For infants with available mortality data, more infants with invasive MSSA infections died at hospital discharge (N=237) than those with invasive MRSA infections (N=110). The proportion of infants who died following invasive MSSA or MRSA infection were similar: 237/2474 (9.6%) and 110/926 (11.9%), P=.05, respectively. Adjusted risk of death at hospital discharge was similar after invasive MSSA and MRSA infections overall (risk ratio, 1.19; 95% CI, 0

  19. Prevalence of Staphylococcus aureus carriage among dogs and their owners

    PubMed Central

    BOOST, M. V.; O'DONOGHUE, M. M.; JAMES, A.

    2008-01-01

    SUMMARY Case reports have indicated transmission of Staphylococcus aureus between humans and pets. We investigated associations between level of contact between dog and owner, and S. aureus colonization. In a cross-sectional study, nasal carriage and antibiotic susceptibility of S. aureus was determined for 830 dogs and 736 owners. Relatedness of isolates was investigated using antibiograms and pulsed-field gel electrophoresis (PFGE). Associations between carriage and demographics or amount of contact between owners and dogs were documented. S. aureus was isolated in 24% of humans and 8·8% of dogs. Antibiotic resistance was significantly more common in canine isolates. Of 17 owner/dog colonized pairs, six were indistinguishable by PFGE. Colonization of dogs was not associated with close human contact, but was strongly associated with health-care occupations (OR 3·29, 95% CI 1·49–7·26, P=0·002). In outbreak situations health-care workers' pets should be considered as a source of S. aureus. High rates of resistance indicate increased monitoring of antibiotic use in veterinary practice is needed. PMID:17678561

  20. Synthesis of catalase in Staphylococcus aureus MF-31.

    PubMed Central

    Martin, S E; Chaven, S

    1987-01-01

    During the growth of Staphylococcus aureus MF-31, initial catalase activity dropped to a reduced level at the onset of exponential phase before increasing. When S. aureus was grown at 25, 32, or 37 degrees C, catalase activity was found to decrease by 80 to 90% within 1 h of inoculation. Two catalase-negative mutants and wild-type S. aureus MF-31 cells were exposed to exogenous 20 mM H2O2 for 15 min. For wild-type S. aureus, there was no effect from H2O2 until min 15, at which time a 10% decrease in CFU was observed. Both mutants showed increased sensitivity to the H2O2, with 56 and 71% reductions in the CFU for mutants C3 and C4, respectively, after a 15-min exposure. Cells of mutant and wild-type S. aureus were subjected to sublethal heating at 52 degrees C for 20 min. The lack of catalase activity in the mutants resulted in large decreases in enumeration. PMID:3606102

  1. Gastrointestinal dissemination and transmission of Staphylococcus aureus following bacteremia.

    PubMed

    Kernbauer, Elisabeth; Maurer, Katie; Torres, Victor J; Shopsin, Bo; Cadwell, Ken

    2015-01-01

    Mutations that alter virulence and antibiotic susceptibility arise and persist during Staphylococcus aureus bacteremia. However, an experimental system demonstrating transmission following bacteremia has been lacking, and thus implications of within-host adaptation for between-host transmission are unknown. We report that S. aureus disseminates to the gastrointestinal tract of mice following intravenous injection and readily transmits to cohoused naive mice. Both intestinal dissemination and transmission were linked to the production of virulence factors based on gene deletion studies of the sae and agr two-component systems. Furthermore, antimicrobial selection for antibiotic-resistant S. aureus displaced susceptible S. aureus from the intestine of infected hosts, which led to the preferential transmission and dominance of antibiotic-resistant bacteria among cohoused untreated mice. These findings establish an animal model to investigate gastrointestinal dissemination and transmission of S. aureus and suggest that adaptation during the course of systemic infection has implications beyond the level of a single host. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Toxin-mediated gene regulatory mechanism in Staphylococcus aureus

    PubMed Central

    Joo, Hwang-Soo; Otto, Michael

    2016-01-01

    The dangerous human pathogen Staphylococcus aureus relies heavily on toxins to cause disease, but toxin production can put a strong burden on the bacteria’s energy balance. Thus, controlling the synthesis of proteins solely needed in times of toxin production represents a way for the bacteria to avoid wasting energy. One hypothetical manner to accomplish this sort of regulation is by gene regulatory functions of the toxins themselves. There have been several reports about gene regulation by toxins in S. aureus, but these were never verified on the molecular level. In our study published in MBio [Joo et al., 7(5). pii: e01579-16], we show that phenol-soluble modulins (PSMs), important peptide toxins of S. aureus, release a repressor from the promoter of the operon encoding the toxin export system, thereby enabling toxin secretion. This study describes the first molecular regulatory mechanism exerted by an S. aureus toxin, setting a paradigmatic example of how S. aureus toxins may influence cell functions to adjust them to times of toxin production.

  3. A systematic review of animal models for Staphylococcus aureus osteomyelitis

    PubMed Central

    Reizner, W.; Hunter, J.G.; O’Malley, N.T.; Southgate, R.D.; Schwarz, E.M.; Kates, S.L.

    2015-01-01

    Staphylococcus aureus (S. aureus) osteomyelitis is a significant complication for orthopaedic patients undergoing surgery, particularly with fracture fixation and arthroplasty. Given the difficulty in studying S. aureus infections in human subjects, animal models serve an integral role in exploring the pathogenesis of osteomyelitis, and aid in determining the efficacy of prophylactic and therapeutic treatments. Animal models should mimic the clinical scenarios seen in patients as closely as possible to permit the experimental results to be translated to the corresponding clinical care. To help understand existing animal models of S. aureus, we conducted a systematic search of PubMed & Ovid MEDLINE to identify in vivo animal experiments that have investigated the management of S. aureus osteomyelitis in the context of fractures and metallic implants. In this review, experimental studies are categorized by animal species and are further classified by the setting of the infection. Study methods are summarized and the relevant advantages and disadvantages of each species and model are discussed. While no ideal animal model exists, the understanding of a model’s strengths and limitations should assist clinicians and researchers to appropriately select an animal model to translate the conclusions to the clinical setting. PMID:24668594

  4. Isolation and characterization of butanol-tolerant Staphylococcus aureus.

    PubMed

    Zhang, Junyan; Huang, Suzhen; Ma, Yuanyuan; Zhang, Minhua; Zou, Shaolan

    2016-11-01

    A new solvent-tolerant species, Staphylococcus aureus, was isolated and characterized during the screening of butanol-tolerant microorganisms. Three isolates of S. aureus were obtained as contaminants during improvement of butanol tolerance of E. coli K12. Their cell dry weights were 135 % that of K12 in the absence of butanol stress. S. aureus had a growth advantage over K12 when cultured with various concentrations of butanol. It can tolerate up to 3 % (v/v) butanol, while most solventogenic bacteria can tolerate only 2 % (v/v) butanol. The addition of 10-20 g glucose/l enhanced its butanol tolerance. The relative cell biomass of the S. aureus was 71-306 % that of E. coli under 5.5-10 % (v/v) ethanol stress, indicating ethanol resistance. This is the first study to observe butanol-tolerant S. aureus. As this organism can be genetically manipulated, it could have a wide array of applications.

  5. The Bicomponent Pore-Forming Leucocidins of Staphylococcus aureus

    PubMed Central

    Alonzo, Francis

    2014-01-01

    SUMMARY The ability to produce water-soluble proteins with the capacity to oligomerize and form pores within cellular lipid bilayers is a trait conserved among nearly all forms of life, including humans, single-celled eukaryotes, and numerous bacterial species. In bacteria, some of the most notable pore-forming molecules are protein toxins that interact with mammalian cell membranes to promote lysis, deliver effectors, and modulate cellular homeostasis. Of the bacterial species capable of producing pore-forming toxic molecules, the Gram-positive pathogen Staphylococcus aureus is one of the most notorious. S. aureus can produce seven different pore-forming protein toxins, all of which are believed to play a unique role in promoting the ability of the organism to cause disease in humans and other mammals. The most diverse of these pore-forming toxins, in terms of both functional activity and global representation within S. aureus clinical isolates, are the bicomponent leucocidins. From the first description of their activity on host immune cells over 100 years ago to the detailed investigations of their biochemical function today, the leucocidins remain at the forefront of S. aureus pathogenesis research initiatives. Study of their mode of action is of immediate interest in the realm of therapeutic agent design as well as for studies of bacterial pathogenesis. This review provides an updated perspective on our understanding of the S. aureus leucocidins and their function, specificity, and potential as therapeutic targets. PMID:24847020

  6. Methicillin-Resistant Staphylococcus aureus Adaptation to Human Keratinocytes

    PubMed Central

    Soong, Grace; Paulino, Franklin; Wachtel, Sarah; Parker, Dane; Wickersham, Matthew; Zhang, Dongni; Brown, Armand; Lauren, Christine; Dowd, Margaret; West, Emily; Horst, Basil; Planet, Paul

    2015-01-01

    ABSTRACT Skin is the most common site of Staphylococcus aureus infection. While most of these infections are self-limited, recurrent infections are common. Keratinocytes and recruited immune cells participate in skin defense against infection. We postulated that S. aureus is able to adapt to the milieu within human keratinocytes to avoid keratinocyte-mediated clearance. From a collection of S. aureus isolated from chronically infected patients with atopic dermatitis, we noted 22% had an agr mutant-like phenotype. Using several models of human skin infection, we demonstrate that toxin-deficient, agr mutants of methicillin-resistant S. aureus (MRSA) USA300 are able to persist within keratinocytes by stimulating autophagy and evading caspase-1 and inflammasome activation. MRSA infection induced keratinocyte autophagy, as evidenced by galectin-8 and LC3 accumulation. Autophagy promoted the degradation of inflammasome components and facilitated staphylococcal survival. The recovery of more than 58% agr or RNAIII mutants (P < 0.0001) of an inoculum of wild-type (WT) MRSA from within wortmannin-treated keratinocytes compared to control keratinocytes reflected the survival advantage for mutants no longer expressing agr-dependent toxins. Our results illustrate the dynamic interplay between S. aureus and keratinocytes that can result in the selection of mutants that have adapted specifically to evade keratinocyte-mediated clearance mechanisms. PMID:25900653

  7. Antibacterial Action of Curcumin against Staphylococcus aureus: A Brief Review

    PubMed Central

    Liew, Kitson; Ali, Syed A.; Khoo, Alan Soo-Beng; Peh, Suat-Cheng

    2016-01-01

    Curcumin, the major constituent of Curcuma longa L. (Zingiberaceae family) or turmeric, commonly used for cooking in Asian cuisine, is known to possess a broad range of pharmacological properties at relatively nontoxic doses. Curcumin is found to be effective against Staphylococcus aureus (S. aureus). As demonstrated by in vitro experiment, curcumin exerts even more potent effects when used in combination with various other antibacterial agents. Hence, curcumin which is a natural product derived from plant is believed to have profound medicinal benefits and could be potentially developed into a naturally derived antibiotic in the future. However, there are several noteworthy challenges in the development of curcumin as a medicine. S. aureus infections, particularly those caused by the multidrug-resistant strains, have emerged as a global health issue and urgent action is needed. This review focuses on the antibacterial activities of curcumin against both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). We also attempt to highlight the potential challenges in the effort of developing curcumin into a therapeutic antibacterial agent. PMID:27956904

  8. Characteristics of Staphylococcus aureus strains isolated from different animal species.

    PubMed

    Devriese, L A; Oeding, P

    1976-11-01

    Staphylococcus aureus strains originating from humans, cows, poultry, pigs, dogs and pigeons were characterised according to the biotyping scheme of Hájek and Marsálek (1971). All strains obtained from poultry, dogs and pigeons and the majority of bovine, human and porcine strains were classifiable as belonging to different biotypes. Two types were found to be present among poultry strains isolated in Europe and Japan. The porcine strains formed a heterogenic collection. One biotype predominated in the other host species. The characteristic S aureus wall teichoic acid (beta-N-acetylglucosaminyl ribitol teichoic acid) was present in nearly all poultry and pig strains. Strains from dogs and pigeons were found to present several properties which were not in agreement with the species description given for S aureus. They did not produce acetoin from glucose and their capacity to produce acid from mannitol in anaerobic conditions was very weak or absent. They were often negative in the clumping factor (slide coagulase) test and usually did not produce hyaluronidase. The production of acid from glucose in anaerobic conditions was slower and less intensive in these strains than in the S aureus strains from other origins. The results of this study support the concept of subdividing the species S aureus into biotypes or ecotypes.

  9. Superantigen Profiling of Staphylococcus aureus Infective Endocarditis Isolates

    PubMed Central

    Chung, Jin-Won; Karau, Melissa J.; Greenwood-Quaintance, Kerryl E.; Ballard, Alessandro D.; Tilahun, Ashenafi; Khaleghi, Shahryar Rostamkolaei; David, Chella S.; Patel, Robin; Rajagopalan, Govindarajan

    2014-01-01

    The frequency of superantigen production among Staphylococcus aureus isolates associated with endocarditis is not well defined. We tested 154 S. aureus isolates from definite infective endocarditis cases for the presence of staphylococcal enterotoxins A-E, H and TSST-1 by PCR, ELISA and using an HLA-DR3 transgenic mouse splenocyte proliferation assay. Sixty-three isolates (50.8%) tested positive for at least one superantigen gene, with 21 (16.9%) testing positive for more than two. tst (28.6%) was most common, followed by seb (27%), sea (22.2%), sed (20.6%), see (17.5%), and sec (11.1%). Of 41 methicillin-resistant S. aureus, 21 had superantigen genes, with sed being more frequently detected in this group compared to methicillin-susceptible S. aureus (P<0.05). Superantigen genes were not associated with mortality (P=0.81). 75% of PCR-positive isolates induced robust splenocyte proliferation. Overall, more than half of S. aureus isolates causing endocarditis carry superantigen genes of which most are functional. PMID:24745820

  10. Prevalence of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Retail Ready-to-Eat Foods in China

    PubMed Central

    Yang, Xiaojuan; Zhang, Jumei; Yu, Shubo; Wu, Qingping; Guo, Weipeng; Huang, Jiahui; Cai, Shuzhen

    2016-01-01

    Staphylococcus aureus, particularly methicillin-resistant S.aureus (MRSA), is a life-threatening pathogen in humans, and its presence in food is a public health concern. MRSA has been identified in foods in China, but little information is available regarding MRSA in ready-to-eat (RTE) foods. We aimed to investigate the prevalence of S. aureus and MRSA in Chinese retail RTE foods. All isolated S. aureus were tested for antimicrobial susceptibility, and MRSA isolates were further characterized by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. Of the 550 RTE foods collected from 2011 to 2014, 69 (12.5%) were positive for S. aureus. Contamination levels were mostly in the range of 0.3–10 most probable number (MPN)/g, with five samples exceeding 10 MPN/g. Of the 69 S. aureus isolates, seven were identified as MRSA by cefoxitin disc diffusion test. Six isolates were mecA-positive, while no mecC-positive isolates were identified. In total, 75.8% (47/62) of the methicillin-susceptible S. aureus isolates and all of the MRSA isolates were resistant to three or more antibiotics. Amongst the MRSA isolates, four were identified as community-acquired strains (ST59-MRSA-IVa (n = 2), ST338-MRSA-V, ST1-MRSA-V), while one was a livestock-associated strain (ST9, harboring an unreported SCCmec type 2C2). One novel sequence type was identified (ST3239), the SCCmec gene of which could not be typed. Overall, our findings showed that Chinese retail RTE foods are likely vehicles for transmission of multidrug-resistant S. aureus and MRSA lineages. This is a serious public health risk and highlights the need to implement good hygiene practices. PMID:27375562

  11. Evaluation of Antimicrobial Resistance in Staphylococcus aureus Isolates by Years

    PubMed Central

    Rağbetli, Cennet; Parlak, Mehmet; Bayram, Yasemin; Guducuoglu, Huseyin; Ceylan, Nesrin

    2016-01-01

    Objective. Recently, community and hospital-acquired infections with Staphylococcus aureus have increased and raised antibiotic resistant isolates. In this study, we aimed to evaluate the antibiotic resistance profile of S. aureus isolates over several years in various clinical specimens from our hospital. Materials and Methods. S. aureus strains from 2009 to 2014 were isolated from various clinical samples at Yuzuncu Yil University, Dursun Odabas Medical Center, Microbiology Laboratory, and their antibiotic susceptibility test results were retrospectively investigated. The isolates were identified by conventional methods, and antibiotic susceptibility tests were performed by the Phoenix (Becton Dickinson, USA) automated system method according to Clinical and Laboratory Standards Institute (CLSI) standards. Results. A total of 1,116 S. aureus isolates were produced and methicillin-resistant S. aureus (MRSA) to 21% of all S. aureus isolates between 2009 and 2014. According to the results of susceptibility tests of all isolates of S. aureus, they have been identified as sensitive to vancomycin, daptomycin, linezolid, and levofloxacin. While the resistance rates to nitrofurantoin, quinupristin-dalfopristin, and trimethoprim-sulfamethoxazole were determined as 0.3%, 2.4%, and 6%, respectively, resistance rates to penicillin, erythromycin, rifampicin, gentamicin, and clindamycin were determined as 100%, 18%, 14%, 14%, and 11%, respectively. The highest percentage of methicillin resistance was determined as 30% in 2009, and the resistance was determined to have decreased in subsequent years (20%, 16%, 13%, 19%, and 21%) (p < 0.001). Conclusion. Currently, retrospective evaluations of causes of nosocomial infection should be done periodically. We think that any alteration of resistance over the years has to be identified, and all centers must determine their own resistance profiles, in order to guide empirical therapies. Reducing the rate of antibiotic resistance will

  12. Staphylococcus aureus small colony variants in diabetic foot infections

    PubMed Central

    Cervantes-García, Estrella; García-Gonzalez, Rafael; Reyes-Torres, Angélica; Resendiz-Albor, Aldo Arturo; Salazar-Schettino, Paz María

    2015-01-01

    Background Staphylococcus aureus (S. aureus) is one of the major pathogens causing chronic infections. The ability of S. aureus to acquire resistance to a diverse range of antimicrobial compounds results in limited treatment options, particularly in methicillin-resistant S. aureus (MRSA). A mechanism by which S. aureus develops reduced susceptibility to antimicrobials is through the formation of small colony variants (SCVs). Infections by SCVs of S. aureus are an upcoming problem due to difficulties in laboratory diagnosis and resistance to antimicrobial therapy. Methods A prospective study was performed on 120 patients diagnosed with both type 2 diabetes mellitus and infected diabetic foot ulcers. The study was carried out from July 2012 to December 2013 in Hospital General de Mexico. The samples were cultured in blood agar, mannitol salt agar, and MacConkey agar media, and incubated at 37°C in aerobic conditions. Results We describe the first known cases of diabetic foot infections caused by MRSA-SCVs in patients diagnosed with type 2 diabetes mellitus and infected diabetic foot ulcers. In all of our cases, the patients had not received any form of gentamicin therapy. Conclusions The antibiotic therapy commonly used in diabetic patients with infected diabetic foot ulcers fails in the case of MRSA-SCVs because the intracellular location protects S. aureus-SCVs from the host's defenses and also helps them resist antibiotics. The cases studied in this article add to the spectrum of persistent and relapsing infections attributed to MRSA-SCVs and emphasizes that these variants may also play a relevant role in diabetic foot infections. PMID:25787018

  13. Staphylococcus aureus from the German general population is highly diverse.

    PubMed

    Becker, Karsten; Schaumburg, Frieder; Fegeler, Christian; Friedrich, Alexander W; Köck, Robin

    2017-01-01

    This prospective cohort study evaluates colonization dynamics and molecular characteristics of methicillin-susceptible and - resistant Staphylococcus aureus (MSSA/MRSA) in a German general population. Nasal swabs of 1878 non-hospitalized adults were screened for S. aureus. Participants were screened thrice in intervals of 6-8 months. Isolates were characterized by spa and agr typing, mecA and mecC possession, respectively, and PCRs targeting virulence factors. 40.9% of all participants carried S. aureus at least once while 0.7% of the participants carried MRSA (mainly spa t011). MSSA isolates (n=1359) were associated with 331 different spa types; t084 (7.7%), t091 (6.1%) and t012 (71, 5.2%) were predominant. Of 206 participants carrying S. aureus at all three sampling time points, 14.1% carried the same spa type continuously; 5.3% carried different spa types with similar repeat patterns, but 80.6% carried S. aureus with unrelated spa types. MSSA isolates frequently harboured genes encoding enterotoxins (sec: 16.6%, seg: 63.1%, sei: 64.5%) and toxic shock syndrome toxin (tst: 17.5%), but rarely Panton-Valentine leukocidin (lukS-PV/lukF-PV: 0.2%). MSSA colonizing human nares in the community are clonally highly diverse. Among those constantly carrying S. aureus, clonal lineages changed over time. The proportion of persistent S. aureus carriers was lower than reported elsewhere. Copyright © 2016 Elsevier GmbH. All rights reserved.

  14. Characterization of Staphylococcus aureus Biofilm Formation in Urinary Tract Infection

    PubMed Central

    YOUSEFI, Masoud; POURMAND, Mohammad Reza; FALLAH, Fatemeh; HASHEMI, Ali; MASHHADI, Rahil; NAZARI-ALAM, Ali

    2016-01-01

    Background: The aim of this study was to investigate the antibiotic susceptibility pattern as well as the phenotypic and genotypic biofilm formation ability of Staphylococcus aureus isolates from patients with urinary tract infection (UTI). Methods: A total of 39 isolates of S. aureus were collected from patients with UTI. The antibiotic susceptibility patterns of the isolates were determined by the Kirby-Bauer disk-diffusion. We used the Modified Congo red agar (MCRA) and Microtiter plate methods to assess the ability of biofilm formation. All isolates were examined for determination of biofilm related genes, icaA, fnbA, clfA and bap using PCR method. Results: Linezolid, quinupristin/dalfopristin and chloramphenicol were the most effective agents against S. aureus isolates. Overall, 69.2% of S. aureus isolates were biofilm producers. Resistance to four antibiotics such as nitrofurantoin (71.4% vs. 28.6%, P=0.001), tetracycline (57.7% vs. 42.3%, P=0.028), erythromycin and ciprofloxacin (56% vs. 44%, P=0.017) was higher among biofilm producers than non-biofilm producers. The icaA, fnbA and clfA genes were present in all S. aureus isolates. However, bap gene was not detected in any of the isolates. Conclusion: Our findings reinforce the role of biofilm formation in resistance to antimicrobial agents. Trimethoprimsulfamethoxazole and doxycycline may be used as an effective treatment for UTI caused by biofilm producers S. aureus. Our results suggest that biofilm formation is not dependent to just icaA, fnbA, clfA and bap genes harbor in S. aureus strains. PMID:27252918

  15. Draft Genome Sequences of Vancomycin-Susceptible Staphylococcus aureus Related to Heterogeneous Vancomycin-Intermediate S. aureus

    PubMed Central

    Ramaraj, Thiruvarangan; Matyi, Stephanie A.; Sundararajan, Anitha; Lindquist, Ingrid E.; Devitt, Nicolas P.; Schilkey, Faye D.; Lamichhane-Khadka, Reena; Hoyt, Peter R.; Mudge, Joann

    2014-01-01

    We report the draft genome sequences of three vancomycin-susceptible methicillin-resistant Staphylococcus aureus strains. S. aureus strain MV8 is a sequence type 8 (ST-8) staphylococcal cassette chromosome mec element type IV (SCCmec IV) derivative, while the other two strains (S. aureus MM25 and MM61) are ST-5 SCCmec II strains. MM61 is also closely related to the heterogeneous vancomycin-intermediate S. aureus strain MM66. PMID:25301662

  16. Ecological Overlap and Horizontal Gene Transfer in Staphylococcus aureus and Staphylococcus epidermidis

    PubMed Central

    Méric, Guillaume; Miragaia, Maria; de Been, Mark; Yahara, Koji; Pascoe, Ben; Mageiros, Leonardos; Mikhail, Jane; Harris, Llinos G.; Wilkinson, Thomas S.; Rolo, Joana; Lamble, Sarah; Bray, James E.; Jolley, Keith A.; Hanage, William P.; Bowden, Rory; Maiden, Martin C.J.; Mack, Dietrich; de Lencastre, Hermínia; Feil, Edward J.; Corander, Jukka; Sheppard, Samuel K.

    2015-01-01

    The opportunistic pathogens Staphylococcus aureus and Staphylococcus epidermidis represent major causes of severe nosocomial infection, and are associated with high levels of mortality and morbidity worldwide. These species are both common commensals on the human skin and in the nasal pharynx, but are genetically distinct, differing at 24% average nucleotide divergence in 1,478 core genes. To better understand the genome dynamics of these ecologically similar staphylococcal species, we carried out a comparative analysis of 324 S. aureus and S. epidermidis genomes, including 83 novel S. epidermidis sequences. A reference pan-genome approach and whole genome multilocus-sequence typing revealed that around half of the genome was shared between the species. Based on a BratNextGen analysis, homologous recombination was found to have impacted on 40% of the core genes in S. epidermidis, but on only 24% of the core genes in S. aureus. Homologous recombination between the species is rare, with a maximum of nine gene alleles shared between any two S. epidermidis and S. aureus isolates. In contrast, there was considerable interspecies admixture of mobile elements, in particular genes associated with the SaPIn1 pathogenicity island, metal detoxification, and the methicillin-resistance island SCCmec. Our data and analysis provide a context for considering the nature of recombinational boundaries between S. aureus and S. epidermidis and, the selective forces that influence realized recombination between these species. PMID:25888688

  17. Ecological Overlap and Horizontal Gene Transfer in Staphylococcus aureus and Staphylococcus epidermidis.

    PubMed

    Méric, Guillaume; Miragaia, Maria; de Been, Mark; Yahara, Koji; Pascoe, Ben; Mageiros, Leonardos; Mikhail, Jane; Harris, Llinos G; Wilkinson, Thomas S; Rolo, Joana; Lamble, Sarah; Bray, James E; Jolley, Keith A; Hanage, William P; Bowden, Rory; Maiden, Martin C J; Mack, Dietrich; de Lencastre, Hermínia; Feil, Edward J; Corander, Jukka; Sheppard, Samuel K

    2015-04-16

    The opportunistic pathogens Staphylococcus aureus and Staphylococcus epidermidis represent major causes of severe nosocomial infection, and are associated with high levels of mortality and morbidity worldwide. These species are both common commensals on the human skin and in the nasal pharynx, but are genetically distinct, differing at 24% average nucleotide divergence in 1,478 core genes. To better understand the genome dynamics of these ecologically similar staphylococcal species, we carried out a comparative analysis of 324 S. aureus and S. epidermidis genomes, including 83 novel S. epidermidis sequences. A reference pan-genome approach and whole genome multilocus-sequence typing revealed that around half of the genome was shared between the species. Based on a BratNextGen analysis, homologous recombination was found to have impacted on 40% of the core genes in S. epidermidis, but on only 24% of the core genes in S. aureus. Homologous recombination between the species is rare, with a maximum of nine gene alleles shared between any two S. epidermidis and S. aureus isolates. In contrast, there was considerable interspecies admixture of mobile elements, in particular genes associated with the SaPIn1 pathogenicity island, metal detoxification, and the methicillin-resistance island SCCmec. Our data and analysis provide a context for considering the nature of recombinational boundaries between S. aureus and S. epidermidis and, the selective forces that influence realized recombination between these species.

  18. Predictors of Staphylococcus aureus Colonization and Results after Decolonization

    PubMed Central

    Malcolm, Tennison L.; Robinson, Le Don; Klika, Alison K.; Ramanathan, Deepak; Higuera, Carlos A.

    2016-01-01

    Protocols for the screening and decolonization of Staphylococcus aureus prior to total joint arthroplasty (TJA) have become widely adopted. The goals of this study were to determine: (1) whether implementation of a screening protocol followed by decolonization with mupirocin/vancomycin and chlorhexidine reduces the risk of revision compared with no screening protocol (i.e., chlorhexidine alone) and (2) whether clinical criteria could reliably predict colonization with MSSA and/or MRSA. Electronic medical records of primary patients undergoing TJA that were screened (n = 3,927) and were not screened (n = 1,751) for Staphylococcus aureus at least 4 days prior to surgery, respectively, were retrospectively reviewed. All patients received chlorhexidine body wipes preoperatively. Patients carrying MSSA and MRSA were treated preoperatively with mupirocin and vancomycin, respectively, along with the standard preoperative antibiotics and chlorhexidine body wipes. Screened patients were 50% less likely to require revision due to prosthetic joint infection compared to those not screened (p = 0.04). Multivariate regression models were poorly accurate in predicting colonization with MSSA (AUC = 0.58) and MRSA (AUC = 0.62). These results support the routine screening and decolonization of S. aureus prior to TJA. PMID:27528869

  19. Transduction of resistance to some macrolide antibiotics in Staphylococcus aureus.

    PubMed

    PATTEE, P A; BALDWIN, J N

    1962-11-01

    Pattee, P. A. (Iowa State University, Ames) and J. N. Baldwin. Transduction of resistance to some macrolide antibiotics in Staphylococcus aureus. J. Bacteriol. 84:1049-1055. 1962.-By use of phage 80 of the International Typing Series, propagated on appropriate strains of Staphylococcus aureus, two related markers controlling resistance to certain macrolide antibiotics (erythromycin, oleandomycin, spiramycin, and carbomycin) were transduced among a variety of strains of S. aureus. Unlike the markers controlling penicillinase production and resistance to chlortetracycline and novobiocin, the determinants of resistance to the macrolide antibiotics were transduced at normal frequencies (at least 300 transductants per 10(9) phage) only to certain of the recipient strains. One of the markers studied appears to control an inducible enzyme system which is specifically induced by sub-inhibitory concentrations of erythromycin and which controls resistance to erythromycin, oleandomycin, spiramycin, and carbomycin. The other marker examined confers resistance to erythromycin, oleandomycin, spiramycin, and carbomycin, and shows no evidence of being dependent upon an inducible mechanism.

  20. Nanoscale Plasma Coating Inhibits Formation of Staphylococcus aureus Biofilm

    PubMed Central

    Xu, Yuanxi; Jones, John E.; Yu, Haiqing; Yu, Qingsong; Christensen, Gordon D.

    2015-01-01

    Staphylococcus aureus commonly infects medical implants or devices, with devastating consequences for the patient. The infection begins with bacterial attachment to the device, followed by bacterial multiplication over the surface of the device, generating an adherent sheet of bacteria known as a biofilm. Biofilms resist antimicrobial therapy and promote persistent infection, making management difficult to futile. Infections might be prevented by engineering the surface of the device to discourage bacterial attachment and multiplication; however, progress in this area has been limited. We have developed a novel nanoscale plasma coating technology to inhibit the formation of Staphylococcus aureus biofilms. We used monomeric trimethylsilane (TMS) and oxygen to coat the surfaces of silicone rubber, a material often used in the fabrication of implantable medical devices. By quantitative and qualitative analysis, the TMS/O2 coating significantly decreased the in vitro formation of S. aureus biofilms; it also significantly decreased in vivo biofilm formation in a mouse model of foreign-body infection. Further analysis demonstrated TMS/O2 coating significantly changed the protein adsorption, which could lead to reduced bacterial adhesion and biofilm formation. These results suggest that TMS/O2 coating can be used to effectively prevent medical implant-related infections. PMID:26369955

  1. Use of natural antimicrobials from a food safety perspective for control of Staphylococcus aureus.

    PubMed

    Li, Min; Muthaiyan, Arunachalam; O'Bryan, Corliss A; Gustafson, John E; Li, Y; Crandall, Philip G; Ricke, Steven C

    2011-08-01

    Staphylococcus aureus (S. aureus) is an important foodborne and environmental pathogen that can produce toxins in foods and cause infections in soft tissues. S. aureus that have developed resistance to the conventional antimicrobials are commonly called Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin-Resistant S. aureus (VRSA). Their prevalence is believed to be due to the widespread use of antibiotics. Therefore, natural antimicrobials are in urgent demand as alternatives to conventional antibiotics to treat S. aureus infections. In this review, natural antimicrobials from plant, animal and microbiological origins are discussed, including their mode of action and mechanisms of bacterial resistance, major components, chemical structure, effectiveness, synergistic effects and future prospects.

  2. Differentiation of Staphylococcus aureus and Staphylococcus epidermidis by PCR for the fibrinogen binding protein gene.

    PubMed

    Sunagar, R; Deore, S N; Deshpande, P V; Rizwan, A; Sannejal, A D; Sundareshan, S; Rawool, D B; Barbuddhe, S B; Jhala, M K; Bannalikar, A S; Mugalikar, D M; Kumari, V J; Dhanalakshmi, K; Reddy, Y N; Rao, P P; Babra, C; Tiwari, J G; Mukkur, T K; Costantino, P; Wetherall, J D; Isloor, S; Hegde, N R

    2013-05-01

    Mastitis is one of the most common and burdensome diseases afflicting dairy animals. Among other causes of mastitis, staphylococci are frequently associated with clinical and subclinical mastitis. Although Staphylococcus aureus is the predominant species involved, Staphylococcus epidermidis and other coagulase-negative staphylococci are increasingly being isolated from cases of bovine mastitis. Although Staph. aureus and Staph. epidermidis can be easily differentiated based on their biochemical properties, such phenotypic identification is time consuming and laborious. This study aimed to rapidly identify Staph. aureus and Staph. epidermidis. Accordingly, a multiplex PCR was developed and we found that a single gene encoding the adhesin fibrinogen binding protein could be used to identify and differentiate the two species. Consequently, a multiplex reaction combining a triplex PCR for Staph. aureus and a duplex PCR for Staph. epidermidis was standardized, first using bacterial cultures and then with pasteurized milk spiked with live organisms or DNA extracted from the organisms. The test could specifically detect Staph. aureus and Staph. epidermidis even in the presence of a dozen other organisms. The limit of detection for detecting Staph. aureus and Staph. epidermidis separately was 10 to 100 cfu/mL for simplex PCR and 10(4)cfu/mL for multiplex PCR. Conversely, the limit was 10(6)cfu/mL by multiplex PCR for simultaneous detection of both the organisms when spiked into culture medium or pasteurized milk. Overnight enrichment enhanced the assay sensitivity 100-fold. The assay had a high diagnostic sensitivity and specificity. The application of the test was verified on 602 field isolates of staphylococci that had been characterized earlier by phenotypic methods. Importantly, 25 coagulase-negative isolates were identified as Staph. aureus by the multiplex PCR. The test could be adapted for use in clinical diagnostic laboratories.

  3. Staphylococcus aureus resistance to topical antimicrobials in atopic dermatitis*

    PubMed Central

    Bessa, Giancarlo Rezende; Quinto, Vanessa Petry; Machado, Daiane Corrêa; Lipnharski, Caroline; Weber, Magda Blessmann; Bonamigo, Renan Rangel; D'Azevedo, Pedro Alves

    2016-01-01

    Background Topical antimicrobial drugs are indicated for limited superficial pyodermitis treatment, although they are largely used as self-prescribed medication for a variety of inflammatory dermatoses, including atopic dermatitis. Monitoring bacterial susceptibility to these drugs is difficult, given the paucity of laboratory standardization. Objective To evaluate the prevalence of Staphylococcus aureus topical antimicrobial drug resistance in atopic dermatitis patients. Methods We conducted a cross-sectional study of children and adults diagnosed with atopic dermatitis and S. aureus colonization. We used miscellaneous literature reported breakpoints to define S. aureus resistance to mupirocin, fusidic acid, gentamicin, neomycin and bacitracin. Results A total of 91 patients were included and 100 S. aureus isolates were analyzed. All strains were methicillin-susceptible S. aureus. We found a low prevalence of mupirocin and fusidic acid resistance (1.1% and 5.9%, respectively), but high levels of neomycin and bacitracin resistance (42.6% and 100%, respectively). Fusidic acid resistance was associated with more severe atopic dermatitis, demonstrated by higher EASI scores (median 17.8 vs 5.7, p=.009). Our results also corroborate the literature on the absence of cross-resistance between the aminoglycosides neomycin and gentamicin. Conclusions Our data, in a southern Brazilian sample of AD patients, revealed a low prevalence of mupirocin and fusidic acid resistance of S. aureus atopic eczema colonizer strains. However, for neomycin and bacitracin, which are commonly used topical antimicrobial drugs in Brazil, high levels of resistance were identified. Further restrictions on the use of these antimicrobials seem necessary to keep resistance as low as possible. PMID:27828633

  4. New epidemiology of Staphylococcus aureus infection in Asia.

    PubMed

    Chen, C-J; Huang, Y-C

    2014-07-01

    Not only is Asia the most populous region in the world, but inappropriate therapy, including self-medication with over-the-counter antimicrobial agents, is a common response to infectious diseases. The high antibiotic selective pressure among the overcrowded inhabitants creates an environment that is suitable for the rapid development and efficient spread of numerous multidrug-resistant pathogens. Indeed, Asia is among the regions with the highest prevalence rates of healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and community-associated methicillin-resistant S. aureus (CA-MRSA) in the world. Most hospitals in Asia are endemic for multidrug-resistant methicillin-resistant S. aureus (MRSA), with an estimated proportion from 28% (in Hong Kong and Indonesia) to >70% (in Korea) among all clinical S. aureus isolates in the early 2010s. Isolates with reduced susceptibility or a high level of resistance to glycopeptides have also been increasingly identified in the past few years. In contrast, the proportion of MRSA among community-associated S. aureus infections in Asian countries varies markedly, from <5% to >35%. Two pandemic HA-MRSA clones, namely multilocus sequence type (ST) 239 and ST5, are disseminated internationally in Asia, whereas the molecular epidemiology of CA-MRSA in Asia is characterized by clonal heterogeneity, similar to that in Europe. In this review, the epidemiology of S. aureus in both healthcare facilities and communities in Asia is addressed, with an emphasis on the prevalence, clonal structure and antibiotic resistant profiles of the MRSA strains. The novel MRSA strains from livestock animals have been considered to constitute a public health threat in western countries. The emerging livestock-associated MRSA strains in Asia are also included in this review.

  5. Staphylococcus aureus Keratitis: A Review of Hospital Cases

    PubMed Central

    Ong, Sherine Jue; Huang, Yhu-Chering; Tan, Hsin-Yuan; Ma, David H. K.; Lin, Hsin-Chiung; Yeh, Lung-Kun; Chen, Phil Y. F.; Chen, Hung-Chi; Chuang, Chih-Chun; Chang, Chee-Jen; Hsiao, Ching-Hsi

    2013-01-01

    Background Methicillin-resistant Staphylococcus aureus (MRSA) infection is an important public health issue. The study aimed to characterize the patient demographics, clinical features, antibiotic susceptibility, and clinical outcomes of keratitis caused by S. aureus, and to make a comparison between MRSA and methicillin-sensitive S. aureus (MSSA) isolates. Methodology/Principal findings Patients (n = 59) with culture-proven S. aureus keratitis treated in Chang Gung Memorial Hospital between January 1, 2006, and December 31, 2010, were included in our study. Patients' demographic and clinical data were retrospectively reviewed. Twenty-six MRSA (44%) and 33 MSSA (56%) isolates were collected. The MRSA keratitis was significantly more common among the patients with healthcare exposure (P = 0.038), but 46.2% (12/26) of patients with MRSA keratitis were considered to have community-associated infections. All isolates were susceptible to vancomycin. MRSA isolates were significantly more resistant to clindamycin, erythromycin, and sulfamethoxazole/trimethoprim. Ocular surface disease was a significant risk factor for MRSA keratitis (P = 0.011). Visual outcome did not differ significantly between the MRSA and MSSA groups. However, age (B = 0.01, P = 0.035, 95% confidence interval [CI]: 0.001–0.019) and visual acuity at presentation (B = 0.749, P<0.001, 95% CI: 0.573–0.926) were significantly correlated with visual outcome. Conclusions/Significance Ocular surface disease is an important predisposing factor for S. aureus keratitis, especially for MRSA infections. Advanced age and poor visual acuity at presentation are important prognostic indicators for poor visual outcome in S. aureus keratitis. Oxacillin resistance may not be a significant prognostic indicator. PMID:24244625

  6. Psoriasis and staphylococcus aureus skin colonization in Moroccan patients

    PubMed Central

    Elfatoiki, Fatima Zahra; El Azhari, Mohamed; El Kettani, Assiya; Serhier, Zineb; Othmani, Mohamed Bennani; Timinouni, Mohamed; Benchikhi, Hakima; Chiheb, Soumiya; Fellah, Hassan

    2016-01-01

    Psoriatic lesions are rarely complicated by recurrent infections. The aim of our study is to determine skin colonisation and nasal carriage of Staphylococcus aureus in patients with psoriasis and in healthy persons. Patients and methods: a comparative study that include 33 patients with psoriasis and 33 healthy persons. Samples were taken from lesional and non lesional psoriatic skin and from healthy skin of control group. For S. aureus nasal carriage, we used sterile cotton tipped swabs. Out of165 samples (66 skin samples and 33 nasal swabs), 26 S. Aureus strains were isolated in 26 persons, 57.69% in the control group and 42.3% in the psoriasisgroup. S. aureus skin colonization was found in one case (3%) inlesional psoriatic skin vs 9 cases (27.3%) in control skin OR=0.08 IC 95% (0.01-0.70) p=0.02 and in 12,1% in non lesional soriatic skin vs 27, 3% in control skin (p =0,13). This colonization was less important in lesional psoriatic skin (3%) than in non lesional psoriatic skin (12.1%) p= 0.20. Nasal screening identified (7/33) 21, 21% S. aureus carriers in psoriasis group and in control group. Our results are in consensus withliterature findings. They have confirmed the importance of antimicrobial peptides in Innateimmunity of human skin. These peptides are normally produced bykeratinocytes in response to inflammatory stimuli such as psoriasis. Their high expression in psoriasis skin reduces the risk of skin infection and skin colonization with S. Aureus. PMID:27200138

  7. Manipulation of Autophagy in Phagocytes Facilitates Staphylococcus aureus Bloodstream Infection.

    PubMed

    O'Keeffe, Kate M; Wilk, Mieszko M; Leech, John M; Murphy, Alison G; Laabei, Maisem; Monk, Ian R; Massey, Ruth C; Lindsay, Jodi A; Foster, Timothy J; Geoghegan, Joan A; McLoughlin, Rachel M

    2015-09-01

    The capacity for intracellular survival within phagocytes is likely a critical factor facilitating the dissemination of Staphylococcus aureus in the host. To date, the majority of work on S. aureus-phagocyte interactions has focused on neutrophils and, to a lesser extent, macrophages, yet we understand little about the role played by dendritic cells (DCs) in the direct killing of this bacterium. Using bone marrow-derived DCs (BMDCs), we demonstrate for the first time that DCs can effectively kill S. aureus but that certain strains of S. aureus have the capacity to evade DC (and macrophage) killing by manipulation of autophagic pathways. Strains with high levels of Agr activity were capable of causing autophagosome accumulation, were not killed by BMDCs, and subsequently escaped from the phagocyte, exerting significant cytotoxic effects. Conversely, strains that exhibited low levels of Agr activity failed to accumulate autophagosomes and were killed by BMDCs. Inhibition of the autophagic pathway by treatment with 3-methyladenine restored the bactericidal effects of BMDCs. Using an in vivo model of systemic infection, we demonstrated that the ability of S. aureus strains to evade phagocytic cell killing and to survive temporarily within phagocytes correlated with persistence in the periphery and that this effect is critically Agr dependent. Taken together, our data suggest that strains of S. aureus exhibiting high levels of Agr activity are capable of blocking autophagic flux, leading to the accumulation of autophagosomes. Within these autophagosomes, the bacteria are protected from phagocytic killing, thus providing an intracellular survival niche within professional phagocytes, which ultimately facilitates dissemination.

  8. Within-Host Evolution of Staphylococcus aureus during Asymptomatic Carriage

    PubMed Central

    Miller, Ruth R.; Farr, Helen; Young, Bernadette C.; Larner-Svensson, Hanna; Fung, Rowena; Godwin, Heather; Knox, Kyle; Votintseva, Antonina; Everitt, Richard G.; Street, Teresa; Cule, Madeleine; Ip, Camilla L. C.; Didelot, Xavier; Peto, Timothy E. A.; Harding, Rosalind M.; Wilson, Daniel J.; Crook, Derrick W.; Bowden, Rory

    2013-01-01

    Background Staphylococcus aureus is a major cause of healthcare associated mortality, but like many important bacterial pathogens, it is a common constituent of the normal human body flora. Around a third of healthy adults are carriers. Recent evidence suggests that evolution of S. aureus during nasal carriage may be associated with progression to invasive disease. However, a more detailed understanding of within-host evolution under natural conditions is required to appreciate the evolutionary and mechanistic reasons why commensal bacteria such as S. aureus cause disease. Therefore we examined in detail the evolutionary dynamics of normal, asymptomatic carriage. Sequencing a total of 131 genomes across 13 singly colonized hosts using the Illumina platform, we investigated diversity, selection, population dynamics and transmission during the short-term evolution of S. aureus. Principal Findings We characterized the processes by which the raw material for evolution is generated: micro-mutation (point mutation and small insertions/deletions), macro-mutation (large insertions/deletions) and the loss or acquisition of mobile elements (plasmids and bacteriophages). Through an analysis of synonymous, non-synonymous and intergenic mutations we discovered a fitness landscape dominated by purifying selection, with rare examples of adaptive change in genes encoding surface-anchored proteins and an enterotoxin. We found evidence for dramatic, hundred-fold fluctuations in the size of the within-host population over time, which we related to the cycle of colonization and clearance. Using a newly-developed population genetics approach to detect recent transmission among hosts, we revealed evidence for recent transmission between some of our subjects, including a husband and wife both carrying populations of methicillin-resistant S. aureus (MRSA). Significance This investigation begins to paint a picture of the within-host evolution of an important bacterial pathogen during its

  9. Characterization of Staphylococcus aureus infections in children with Down syndrome.

    PubMed

    Johnston, Jeffrey N; Kaplan, Sheldon L; Mason, Edward O; Hulten, Kristina G

    2015-11-01

    Staphylococcus aureus infections in the Down syndrome (DS) population have not been well characterized. This study determined clinical and molecular characteristics of S. aureus infections in children with DS followed at Texas Children's Hospital (TCH), from 2001 to 2011. Patients were retrospectively identified from an ongoing S. aureus surveillance study. Medical records were reviewed. Isolates were characterized by antimicrobial susceptibility, pulsed-field gel electrophoresis patterns, and detection of PVL genes (pvl), mupA (high-level mupirocin resistance gene), smr (chlorhexidine resistance conferring gene), and Staphylococcal Chromosomal Cassette mec (SCCmec) type. Twenty-six patients with DS had a total of 34 S. aureus infections (8 recurrent); 61% were MRSA. DS patients represented 16.8 per 10,000 community onset S. aureus infections seen at TCH. Among 26 initial infections 17 were skin and soft tissue (SSTI), 7 were outer or middle ear and 2 were invasive infections. Seventeen patients were hospitalized. Thirteen (65%) of 20 available isolates were USA300, 14 were pvl+, 5 were mupA+, and 8 were smr+. Five of 8 (63%) recurrent infections were ear infections. All 4 recurrent ear isolates available for study were smr+, ciprofloxacin non-susceptible and treated with ciprofloxacin otic drops. S. aureus infections among patients with DS were similar in presentation to other patient groups, except for a greater proportion being associated with ear infections. Seventy percent of ear fluid isolates carried antiseptic and fluoroquinolone resistance genes. A study of a greater number of DS patients is warranted to further explore these findings.

  10. Superantigens of Staphylococcus aureus From Patients With Diabetic Foot Ulcers

    PubMed Central

    Vu, Bao G.; Stach, Christopher S.; Salgado-Pabón, Wilmara; Diekema, Daniel J.; Gardner, Sue E.; Schlievert, Patrick M.

    2014-01-01

    Background Diabetic foot ulcer (DFU) infections are challenging. Staphylococcus aureus is the most commonly isolated pathogen in DFUs. Superantigens (SAgs) are causative in many S. aureus infections. We hypothesized both that DFU S. aureus will produce large SAg numbers, consistent with skin infections, and that certain SAgs will be overrepresented. We assessed the SAg and α-toxin profile of isolates from patients with DFU, compared with profiles of isolates from other sources. Materials Twenty-five S. aureus isolates from patients with DFU were characterized. Polymerase chain reaction was used to detect genes for methicillin-resistance and SAgs. Some SAgs and the α-toxin were quantified. We compared the SAg profile of DFU isolates with SAg profiles of S. aureus isolates from skin lesions of patients with atopic dermatitis and from vaginal mucosa of healthy individuals. Results Most DFU isolates were methicillin susceptible (64%), with USA100 the most common clonal group. The SAg gene profile of DFU isolates most closely resembled that of isolates from patients with atopic dermatitis, with the highest number of different SAg genes per isolate and a high prevalence of staphylococcal enterotoxin D and the enterotoxin gene cluster. DFU isolates also had a high prevalence of staphylococcal enterotoxin-like X. Conclusions Comparison of the SAg profile of DFU isolates to SAg profiles of skin lesion isolates and vaginal mucosa isolates revealed that the SAg profile of DFU isolates was more similar to that of skin lesion isolates. SAgs offer selective advantages in facilitating DFU infections and suggest that therapies to neutralize or reduce SAg production by S. aureus may be beneficial in management of patients with DFU. PMID:24951827

  11. Outstanding Prevalence of Methicillin Resistant Staphylococcus aureus in Neonatal Omphalitis

    PubMed Central

    Sengupta, Mallika; Banerjee, Pritam; Guchhait, Partha

    2016-01-01

    Introduction Omphalitis is the infection of the umbilical cord stump, which can lead to septicaemia and significant neonatal morbidity and mortality. Very little data is available on the aetiology of neonatal omphalitis in India. Aim To identify the causative agents of omphalitis in neonates and determine the antimicrobial susceptibility patterns of the isolates. Materials and Methods A prospective study was conducted at ESI-PGIMSR and ESIC Medical College, Joka, a tertiary care teaching hospital in Eastern India for a period of four months (from 1st January 2016 to 30th April 2016). Neonates were screened for omphalitis on the basis of presence of pus and redness for inclusion. Clinical examination, Gram stain and culture of umbilical discharge, identification of organisms by biochemical tests and VITEK 2 Compact (bioMereiux Inc., France) was done. Antimicrobial susceptibility by Kirby Bauer disc diffusion method and E-strip agar diffusion method (for vancomycin and teicoplanin) were performed and interpreted according to the Clinical and Laboratory Standards Institute (CLSI) guidelines version 2015. Results A total of 623 neonates were screened, among whom 21 (3.37%) were positive for our screening criteria for omphalitis. Cultures from the exudates of those cases yielded growth of Staphylococcus aureus in 19 (90.47%) samples, all of which were found to be methicillin resistant Staphylococcus aureus (MRSA). Resistance to erythromycin was seen among 36.82% isolates and inducible clindamycin resistance was seen among 31.57% isolates of Staphylococcus aureus. Conclusion MRSA can be the most common cause of omphalitis. However, this finding needs to be evaluated in larger prospective studies. PMID:27790440

  12. An overview of Staphylococcus epidermidis and Staphylococcus aureus with a focus on developing countries.

    PubMed

    Chessa, Daniela; Ganau, Giulia; Mazzarello, Vittorio

    2015-07-04

    Most nosocomial infections by Staphylococcus epidermidis and Staphylococcus aureus have gained considerable attention due to an increase of infections caused by these strains that have been reported in recent years throughout the world. Most notably, it is important to underline the presence of S. epidermidis and S. aureus in the human epithelia microflora and to highlight that it is impossible to eradicate them from humans. There are various virulence factors that normally sustain the infection life cycle, such as antibiotic resistance (methicillin resistance). Furthermore, it is important to evaluate the usefulness of typing the spa gene from isolated strains in order to study genotypes and geographical distributions. In the present review, different cases related to patients infected by Staphylococci and an overview of this problem worldwide are reported.

  13. Cavity Forming Pneumonia Due to Staphylococcus aureus Following Dengue Fever.

    PubMed

    Miyata, Nobuyuki; Yoshimura, Yukihiro; Tachikawa, Natsuo; Amano, Yuichiro; Sakamoto, Yohei; Kosuge, Youko

    2015-11-01

    While visiting Malaysia, a 22-year-old previously healthy Japanese man developed myalgia, headache, and fever, leading to a diagnosis of classical dengue fever. After improvement and returning to Japan after a five day hospitalization, he developed productive cough several days after defervescing from dengue. Computed tomography (CT) thorax scan showed multiple lung cavities. A sputum smear revealed leukocytes with phagocytized gram-positive cocci in clusters, and grew an isolate Staphylococcus aureus sensitive to semi-synthetic penicillin; he was treated successfully with ceftriaxone and cephalexin. This second reported case of pneumonia due to S. aureus occurring after dengue fever, was associated both with nosocomial exposure and might have been associated with dengue-associated immunosuppression. Clinicians should pay systematic attention to bacterial pneumonia following dengue fever to establish whether such a connection is causally associated. © The American Society of Tropical Medicine and Hygiene.

  14. Community-Associated Methicillin-Resistant Staphylococcus aureus Case Studies

    PubMed Central

    Sowash, Madeleine G.; Uhlemann, Anne-Catrin

    2014-01-01

    Over the past decade, the emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has changed the landscape of S. aureus infections around the globe. Initially recognized for its ability to cause disease in young and healthy individuals without healthcare exposures as well as for its distinct genotype and phenotype, this original description no longer fully encompasses the diversity of CA-MRSA as it continues to expand its niche. Using four case studies, we highlight a wide range of the clinical presentations and challenges of CA-MRSA. Based on these cases we further explore the globally polygenetic background of CA-MRSA with a special emphasis on generally less characterized populations. PMID:24085688

  15. Staphylococcus aureus Infections: Epidemiology, Pathophysiology, Clinical Manifestations, and Management

    PubMed Central

    Davis, Joshua S.; Eichenberger, Emily; Holland, Thomas L.

    2015-01-01

    SUMMARY Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions. PMID:26016486

  16. Glucose Augments Killing Efficiency of Daptomycin Challenged Staphylococcus aureus Persisters.

    PubMed

    Prax, Marcel; Mechler, Lukas; Weidenmaier, Christopher; Bertram, Ralph

    2016-01-01

    Treatment of Staphylococcus aureus in stationary growth phase with high doses of the antibiotic daptomycin (DAP) eradicates the vast majority of the culture and leaves persister cells behind. Despite resting in a drug-tolerant and dormant state, persister cells exhibit metabolic activity which might be exploited for their elimination. We here report that the addition of glucose to S. aureus persisters treated with DAP increased killing by up to five-fold within one hour. This glucose-DAP effect also occurred with strains less sensitive to the drug. The underlying mechanism is independent of the proton motive force and was not observed with non-metabolizable 2-deoxy-glucose. Our results are consistent with two hypotheses on the glucose-DAP interplay. The first is based upon glucose-induced carbohydrate transport proteins that may influence DAP and the second suggests that glucose may trigger the release or activity of cell-lytic proteins to augment DAP's mode of action.

  17. Evaluation of a New Bactericidal Spray Effective against Staphylococcus aureus

    PubMed Central

    Andersen, Ariel A.

    1963-01-01

    A new germicidal spray consisting of an active ingredient, 2-chloro-4-phenylphenol, solvent, and propellant was evaluated against aerosols of Staphylococcus aureus and spores of Bacillus subtilis. The method of evaluation consisted of determining the decay rate of the bacterial aerosols in a small chamber, with and without the aerial germicide present. The method is unique in that the effect of very short exposures of airborne bacteria to aerial germicides can be measured accurately. By use of the method outlined, extremely potent aerial germicides may be evaluated against highly sensitive organisms. The 2-chloro-4-phenylphenol spray was found to be extremely effective against S. aureus but only moderately effective against spores of B. subtilis. PMID:14012756

  18. Fluorescent reporters for markerless genomic integration in Staphylococcus aureus

    PubMed Central

    de Jong, Nienke W. M.; van der Horst, Thijs; van Strijp, Jos A. G.; Nijland, Reindert

    2017-01-01

    We present integration vectors for Staphylococcus aureus encoding the fluorescent reporters mAmetrine, CFP, sGFP, YFP, mCherry and mKate. The expression is driven either from the sarA-P1 promoter or from any other promoter of choice. The reporter can be inserted markerless in the chromosome of a wide range of S. aureus strains. The integration site chosen does not disrupt any open reading frame, provides good expression, and has no detectable effect on the strains physiology. As an intermediate construct, we present a set of replicating plasmids containing the same fluorescent reporters. Also in these reporter plasmids the sarA-P1 promoter can be replaced by any other promoter of interest for expression studies. Cassettes from the replication plasmids can be readily swapped with the integration vector. With these constructs it becomes possible to monitor reporters of separate fluorescent wavelengths simultaneously. PMID:28266573

  19. The prevalence and mechanisms of vancomycin resistance in Staphylococcus aureus.

    PubMed

    Walsh, Timothy R; Howe, Robin A

    2002-01-01

    The emergence of Staphylococcus aureus resistant to vancomycin has caused considerable concern. Such strains are currently rare, although they have been isolated from many areas of the world. Considerable controversy surrounds strains of S. aureus displaying heterogeneous resistance to vancomycin regarding their definition and methods for detection. This has led to considerable variance in estimates of prevalence (0-1.3%-20% in Japan) and has hindered efforts to define the clinical relevance of these strains. The mechanism of resistance involves a complex reorganization of cell wall metabolism, leading to a grossly thickened cell wall with reduced peptidoglycan cross-linking. There may be many different ways in which strains achieve this endpoint. Current knowledge and theories are summarized.

  20. Octameric structure of Staphylococcus aureus enolase in complex with phosphoenolpyruvate

    PubMed Central

    Wu, Yunfei; Wang, Chengliang; Lin, Shenglong; Wu, Minhao; Han, Lu; Tian, Changlin; Zhang, Xuan; Zang, Jianye

    2015-01-01

    Staphylococcus aureus is a Gram-positive bacterium with strong pathogenicity that causes a wide range of infections and diseases. Enolase is an evolutionarily conserved enzyme that plays a key role in energy production through glycolysis. Additionally, enolase is located on the surface of S. aureus and is involved in processes leading to infection. Here, crystal structures of Sa_enolase with and without bound phosphoenolpyruvate (PEP) are presented at 1.6 and 2.45 Å resolution, respectively. The structure reveals an octameric arrangement; however, both dimeric and octameric conformations were observed in solution. Furthermore, enzyme-activity assays show that only the octameric variant is catalytically active. Biochemical and structural studies indicate that the octameric form of Sa_enolase is enzymatically active in vitro and likely also in vivo, while the dimeric form is catalytically inactive and may be involved in other biological processes. PMID:26627653

  1. [Optimal vancomycin serum level in Staphylococcus aureus infections?].

    PubMed

    Bingen, E; Mariani-Kurkdjian, P; Nebbad, B

    2006-09-01

    Vancomycin is the cornerstone of therapy against methicillin-resistant Staphylococus aureus in both community and nosocomial-acquired infections. Because vancomycin is a concentration-independent or time-dependant antibiotic, most clinicians have abandoned the routine practice of determining peak serum concentrations to rely solely on monitoring serum concentrations. The so-called therapeutic range most often quoted for vancomycin was assessed for through serum concentrations of 5-10 mg/l. But prolonged exposure to serum concentration close to the MIC is associated with the emergence of resistance. More recent guidelines recommended vancomycin in concentrations of 15-20 mg/l for the treatment of severe Staphylococcus infections or in situations where vancomycin penetration is poor. However, because of the great variability of vancomycin MIC(S) (0,12-4 mg/l) of susceptible Staphylococcus strains, guidelines should recommend through serum concentrations of 5-10 times the MIC.

  2. Human Staphylococcus aureus lineages among Zoological Park residents in Greece

    PubMed Central

    Drougka, E.; Foka, A.; Posantzis, D.; Giormezis, N.; Anastassiou, E.D.; Petinaki, E.; Spiliopoulou, I.

    2015-01-01

    Staphylococcus aureus is a part of the microbiota flora in many animal species. The clonal spread of S. aureus among animals and personnel in a Zoological Park was investigated. Samples were collected from colonized and infected sites among 32 mammals, 11 birds and eight humans. The genes mecA, mecC, lukF/lukS-PV (encoding Panton-Valentine leukocidin, PVL) and tst (toxic shock syndrome toxin-1) were investigated by PCR. Clones were defined by Multilocus Sequence Typing (MLST), spa type and Pulsed-Field Gel Electrophoresis (PFGE). Seven S. aureus isolates were recovered from four animals and one from an employee. All were mecA, mecC and tst–negative, whereas, one carried the PVL genes and was isolated from an infected Squirrel monkey. Clonal analysis revealed the occurrence of seven STs, eight PFGE and five spa types including ones of human origin. Even though a variety of genotypes were identified among S. aureus strains colonizing zoo park residents, our results indicate that colonization with human lineages has indeed occurred. PMID:26623381

  3. Menaquinone biosynthesis potentiates haem toxicity in Staphylococcus aureus

    PubMed Central

    Wakeman, Catherine A.; Hammer, Neal D.; Stauff, Devin L.; Attia, Ahmed S.; Anzaldi, Laura L.; Dikalov, Sergey I.; Calcutt, M. Wade; Skaar, Eric P.

    2012-01-01

    Summary Staphylococcus aureus is a pathogen that infects multiple anatomical sites leading to a diverse array of diseases. Although vertebrates can restrict the growth of invading pathogens by sequestering iron within haem, S. aureus surmounts this challenge by employing high-affinity haem uptake systems. However, the presence of excess haem is highly toxic, necessitating tight regulation of haem levels. To overcome haem stress, S. aureus expresses the detoxification system HrtAB. In this work, a transposon screen was performed in the background of a haem-susceptible, HrtAB-deficient S. aureus strain to identify the substrate transported by this putative pump and the source of haem toxicity. While a recent report indicates that HrtAB exports haem itself, the haem-resistant mutants uncovered by the transposon selection enabled us to elucidate the cellular factors contributing to haem toxicity. All mutants identified in this screen inactivated the menaquinone (MK) biosynthesis pathway. Deletion of the final steps of this pathway revealed that quinone molecules localizing to the cell membrane potentiate haem-associated superoxide production and subsequent oxidative damage. These data suggest a model in which membrane-associated haem and quinone molecules form a redox cycle that continuously generates semiquinones and reduced haem, both of which react with atmospheric oxygen to produce superoxide. PMID:23043465

  4. Efficacy of two Staphylococcus aureus phage cocktails in cheese production.

    PubMed

    El Haddad, Lynn; Roy, Jean-Pierre; Khalil, Georges E; St-Gelais, Daniel; Champagne, Claude P; Labrie, Steve; Moineau, Sylvain

    2016-01-18

    Staphylococcus aureus is one of the most prevalent pathogenic bacteria contaminating dairy products. In an effort to reduce food safety risks, virulent phages are investigated as antibacterial agents to control foodborne pathogens. The aim of this study was to compare sets of virulent phages, design phage cocktails, and use them in a cocktail to control pathogenic staphylococci in cheese. Six selected phages belonging to the three Caudovirales families (Myoviridae, Siphoviridae, Podoviridae) were strictly lytic, had a broad host range, and did not carry genes coding for virulence traits in their genomes. However, they were sensitive to pasteurization. At MOI levels of 15, 45, and 150, two anti-S. aureus phage cocktails, each containing three phages, one from each of the three phage families, eradicated a 10(6)CFU/g S. aureus population after 14 days of Cheddar cheese curd ripening at 4°C. The use of these phages did not trigger over-production of S. aureus enterotoxin C. The use of phage cocktails and their rotation may prevent the emergence of phage resistant bacterial strains.

  5. Staphylococcus aureus and Influenza A Virus: Partners in Coinfection

    PubMed Central

    Mulcahy, Michelle E.

    2016-01-01

    ABSTRACT Nasal carriage of Staphylococcus aureus is a significant risk factor for secondary staphylococcal pneumonia in influenza A virus (IAV)-infected hosts. However, little research has been undertaken to define the environmental and physiological changes that cause S. aureus to shift from commensal to pathogenic organism in this setting. The ability of virus-driven danger signals to cause S. aureus to transition from commensalism to pulmonary infection was explored in a recent study by Reddinger et al. R. M. Reddinger, N. R. Luke-Marshall, A. P. Hakansson, and A. A. Campagnari, mBio 7(6):e01235-16, 2016, http://dx.doi.org/10.1128/mBio.01235-16. The authors report that physiological host changes, including febrile temperature and a combination of host stress response signals, caused S. aureus biofilms to disperse from the nasal environment and cause active pulmonary infection. This commentary discusses the new finding in light of the current understanding of the mechanisms behind staphylococcal coinfection with IAV. In addition, it considers the mechanisms behind staphylococcal dispersal in this model. Overall, the study indicates that interkingdom signaling may occur following IAV infection and this likely contributes to sensitizing the IAV-infected host to secondary staphylococcal pneumonia. PMID:27965455

  6. Small Molecule Inhibitors Limit Endothelial Cell Invasion by Staphylococcus aureus

    PubMed Central

    Cordero, Diana; Fullenkamp, Christopher R.; Pelly, Rachel R.; Reed, Katie M.; Caffo, Lindy M.; Zahrt, Ashley N.; Newman, Micaleah; Komanapalli, Sarah; Niemeier, Evan M.; Bishop, Derron L.; Bruns, Heather A.; Haynes, Mark K.; Sklar, Larry A.; Sammelson, Robert E.; McDowell, Susan A.

    2015-01-01

    Staphylococcus aureus is a leading causative agent in sepsis, endocarditis, and pneumonia. An emerging concept is that prognosis worsens when the infecting S. aureus strain has the capacity to not only colonize tissue as an extracellular pathogen, but to invade host cells and establish intracellular bacterial populations. In previous work, we identified host CDC42 as a central regulator of endothelial cell invasion by S. aureus. In the current work, we report that ML 141, a first-in-class CDC42 inhibitor, decreases invasion and resultant pathogenesis in a dose-dependent and reversible manner. Inhibition was found to be due in part to decreased remodeling of actin that potentially drives endocytic uptake of bacteria/fibronectin/integrin complexes. ML 141 decreased binding to fibronectin at these complexes, thereby limiting a key pathogenic mechanism used by S. aureus to invade. Structural analogs of ML 141 were synthesized (designated as the RSM series) and a subset identified that inhibit invasion through non-cytotoxic and non-bactericidal mechanisms. Our results support the development of adjunctive therapeutics targeting host CDC42 for mitigating invasive infection at the level of the host. PMID:25213310

  7. Burn Serum Increases Staphylococcus aureus Biofilm Formation via Oxidative Stress

    PubMed Central

    Yin, Supeng; Jiang, Bei; Huang, Guangtao; Gong, Yali; You, Bo; Yang, Zichen; Chen, Yu; Chen, Jing; Yuan, Zhiqiang; Li, Ming; Hu, Fuquan; Zhao, Yan; Peng, Yizhi

    2017-01-01

    Staphylococcus aureus is a common pathogen isolated from burn patients that can form biofilms on burn wounds and implanted deep vein catheters, which often leads to refractory infections or even biofilm-related sepsis. As biofilm formation is usually regulated by environmental conditions, we hypothesized that serum composition may be altered after burn injury, potentially affecting the ability of infecting bacteria to form biofilms. As predicted, we observed that serum from burn-injured rats increases biofilm formation by S. aureus and also induces bacterial aggregation and adherence to human fibronectin and fibrinogen. Analysis of potential regulatory factors revealed that exposure to burn serum decreases expression of the quorum-sensing agr system and increases mRNA levels of some biofilm inducers such as sarA and icaA. In addition, we also observed that burn serum imposes oxidative stress and increases expression of key oxidoreductase genes (sodA, sodM, katA, and ahpC) in S. aureus. Importantly, the ability of burn serum to enhance biofilm formation and bacterial cell aggregation can be abrogated by treatment with an antioxidant. Taken together, these findings indicate that burn serum increases S. aureus biofilm formation via elevated oxidative stress, and may lead to novel strategies to control biofilm formation and infection in burn patients. PMID:28702016

  8. Staphylococcus aureus colonization related to severity of hand eczema.

    PubMed

    Mernelius, S; Carlsson, E; Henricson, J; Löfgren, S; Lindgren, P-E; Ehricht, R; Monecke, S; Matussek, A; Anderson, C D

    2016-08-01

    Knowledge on Staphylococcus aureus colonization rates and epidemiology in hand eczema is limited. The aim of this study was to clarify some of these issues. Samples were collected by the "glove juice" method from the hands of 59 patients with chronic hand eczema and 24 healthy individuals. Swab samples were taken from anterior nares and throat from 43 of the 59 patients and all healthy individuals. S. aureus were spa typed and analysed by DNA-microarray-based genotyping. The extent of the eczema was evaluated by the hand eczema extent score (HEES). The colonization rate was higher on the hands of hand eczema patients (69 %) compared to healthy individuals (21 %, p < 0.001). This was also seen for bacterial density (p = 0.002). Patients with severe hand eczema (HEES ≥ 13) had a significantly higher S. aureus density on their hands compared to those with milder eczema (HEES = 1 to 12, p = 0.004). There was no difference between patients and healthy individuals regarding colonization rates in anterior nares or throat. spa typing and DNA-microarray-based genotyping indicated certain types more prone to colonize eczematous skin. Simultaneous colonization, in one individual, with S. aureus of different types, was identified in 60-85 % of the study subjects. The colonization rate and density indicate a need for effective treatment of eczema and may have an impact on infection control in healthcare.

  9. Architecture of a Species: Phylogenomics of Staphylococcus aureus.

    PubMed

    Planet, Paul J; Narechania, Apurva; Chen, Liang; Mathema, Barun; Boundy, Sam; Archer, Gordon; Kreiswirth, Barry

    2017-02-01

    A deluge of whole-genome sequencing has begun to give insights into the patterns and processes of microbial evolution, but genome sequences have accrued in a haphazard manner, with biased sampling of natural variation that is driven largely by medical and epidemiological priorities. For instance, there is a strong bias for sequencing epidemic lineages of methicillin-resistant Staphylococcus aureus (MRSA) over sensitive isolates (methicillin-sensitive S. aureus: MSSA). As more diverse genomes are sequenced the emerging picture is of a highly subdivided species with a handful of relatively clonal groups (complexes) that, at any given moment, dominate in particular geographical regions. The establishment of hegemony of particular clones appears to be a dynamic process of successive waves of replacement of the previously dominant clone. Here we review the phylogenomic structure of a diverse range of S. aureus, including both MRSA and MSSA. We consider the utility of the concept of the 'core' genome and the impact of recombination and horizontal transfer. We argue that whole-genome surveillance of S. aureus populations could lead to better forecasting of antibiotic resistance and virulence of emerging clones, and a better understanding of the elusive biological factors that determine repeated strain replacement.

  10. Superantigens in Staphylococcus aureus isolated from prosthetic joint infection

    PubMed Central

    Kim, Choon K.; Karau, Melissa J.; Greenwood-Quaintance, Kerryl E.; Tilahun, Ashenafi Y.; David, Chella S.; Mandrekar, Jayawant N.; Patel, Robin; Rajagopalan, Govindarajan

    2014-01-01

    Staphylococcus aureus is a common cause of prosthetic joint infection (PJI). The prevalence of superantigens (SAgs) among PJI-associated S. aureus is unknown. Eighty-four S. aureus isolates associated with PJI isolated between 1999 and 2006 were studied. SAg genes, sea, seb, sec, sed, see, seg, seh, sei and tst, were assayed by PCR. Seventy-eight (92.9%) isolates carried at least one SAg gene studied, with 61 (72.6%) harboring more than one. seg was most commonly (70.2%) and seh was least frequently (4.8%) detected. tst-positive isolates were associated with early infection and increased ESR at diagnosis (P = 0.006 and P = 0.021, respectively). seg and sei were associated with methicillin resistance (P = 0.008 and 0.002, respectively). SAg genes are prevalent in S. aureus causing PJI; a majority of PJI-associated isolates produce biologically active SAgs in both planktonic and biofilm growth modes. PMID:25619753

  11. Coordination of Chromosome Segregation and Cell Division in Staphylococcus aureus.

    PubMed

    Bottomley, Amy L; Liew, Andrew T F; Kusuma, Kennardy D; Peterson, Elizabeth; Seidel, Lisa; Foster, Simon J; Harry, Elizabeth J

    2017-01-01

    Productive bacterial cell division and survival of progeny requires tight coordination between chromosome segregation and cell division to ensure equal partitioning of DNA. Unlike rod-shaped bacteria that undergo division in one plane, the coccoid human pathogen Staphylococcus aureus divides in three successive orthogonal planes, which requires a different spatial control compared to rod-shaped cells. To gain a better understanding of how this coordination between chromosome segregation and cell division is regulated in S. aureus, we investigated proteins that associate with FtsZ and the divisome. We found that DnaK, a well-known chaperone, interacts with FtsZ, EzrA and DivIVA, and is required for DivIVA stability. Unlike in several rod shaped organisms, DivIVA in S. aureus associates with several components of the divisome, as well as the chromosome segregation protein, SMC. This data, combined with phenotypic analysis of mutants, suggests a novel role for S. aureus DivIVA in ensuring cell division and chromosome segregation are coordinated.

  12. Coordination of Chromosome Segregation and Cell Division in Staphylococcus aureus

    PubMed Central

    Bottomley, Amy L.; Liew, Andrew T. F.; Kusuma, Kennardy D.; Peterson, Elizabeth; Seidel, Lisa; Foster, Simon J.; Harry, Elizabeth J.

    2017-01-01

    Productive bacterial cell division and survival of progeny requires tight coordination between chromosome segregation and cell division to ensure equal partitioning of DNA. Unlike rod-shaped bacteria that undergo division in one plane, the coccoid human pathogen Staphylococcus aureus divides in three successive orthogonal planes, which requires a different spatial control compared to rod-shaped cells. To gain a better understanding of how this coordination between chromosome segregation and cell division is regulated in S. aureus, we investigated proteins that associate with FtsZ and the divisome. We found that DnaK, a well-known chaperone, interacts with FtsZ, EzrA and DivIVA, and is required for DivIVA stability. Unlike in several rod shaped organisms, DivIVA in S. aureus associates with several components of the divisome, as well as the chromosome segregation protein, SMC. This data, combined with phenotypic analysis of mutants, suggests a novel role for S. aureus DivIVA in ensuring cell division and chromosome segregation are coordinated. PMID:28878745

  13. Predictive characterization of hypothetical proteins in Staphylococcus aureus NCTC 8325

    PubMed Central

    School, Kuana; Marklevitz, Jessica; K. Schram, William; K. Harris, Laura

    2016-01-01

    Staphylococcus aureus is one of the most common hospital acquired infections. It colonizes immunocompromised patients and with the number of antibiotic resistant strains increasing, medicine needs new treatment options. Understanding more about the proteins this organism uses would further this goal. Hypothetical proteins are sequences thought to encode a functional protein but for which little to no evidence of that function exists. About half of the genomic proteins in reference strain S. aureus NCTC 8325 are hypothetical. Since annotation of these proteins can lead to new therapeutic targets, a high demand to characterize hypothetical proteins is present. This work examines 35 hypothetical proteins from the chromosome of S. aureus NCTC 8325. Examination includes physiochemical characterization; sequence homology; structural homology; domain recognition; structure modeling; active site depiction; predicted protein-protein interactions; protein-chemical interactions; protein localization; protein stability; and protein solubility. The examination revealed some hypothetical proteins related to virulent domains and protein-protein interactions including superoxide dismutase, O-antigen, bacterial ferric iron reductase and siderophore synthesis. Yet other hypothetical proteins appear to be metabolic or transport proteins including ABC transporters, major facilitator superfamily, S-adenosylmethionine decarboxylase, and GTPases. Progress evaluating some hypothetical proteins, particularly the smaller ones, was incomplete due to limited homology and structural information in public repositories. These data characterizing hypothetical proteins will contribute to the scientific understanding of S. aureus by identifying potential drug targets and aiding in future drug discovery. PMID:28149057

  14. Multiple-Strain Colonization in Nasal Carriers of Staphylococcus aureus

    PubMed Central

    Miller, R. R.; Fung, R.; Knox, K.; Godwin, H.; Peto, T. E. A.; Crook, D. W.; Bowden, R.; Walker, A. S.

    2014-01-01

    Staphylococcus aureus is a commensal that can also cause invasive infection. Reports suggest that nasal cocolonization occurs rarely, but the resources required to sequence multiple colonies have precluded its large-scale investigation. A staged protocol was developed to maximize detection of mixed-spa-type colonization while minimizing laboratory resources using 3,197 S. aureus-positive samples from a longitudinal study of healthy individuals in Oxfordshire, United Kingdom. Initial typing of pooled material from each sample identified a single unambiguous strain in 89.6% of samples. Twelve single-colony isolates were typed from samples producing ambiguous initial results. All samples could be resolved into one or more spa types using the protocol. Cocolonization point prevalence was 3.4 to 5.8% over 24 months of follow-up in 360 recruitment-positives. However, 18% were cocolonized at least once, most only transiently. Cocolonizing spa types were completely unrelated in 56% of samples. Of 272 recruitment-positives returning ≥12 swabs, 166 (61%) carried S. aureus continuously but only 106 (39%) carried the same single spa type without any cocolonization; 31 (11%) switched spa type and 29 (11%) had transient cocarriage. S. aureus colonization is dynamic even in long-term carriers. New unrelated cocolonizing strains could increase invasive disease risk, and ongoing within-host evolution could increase invasive potential, possibilities that future studies should explore. PMID:24501033

  15. Putative link between Staphylococcus aureus bacteriophage serotype and community association.

    PubMed

    Mohamed, D H; Saberesheikh, S; Kearns, A M; Saunders, N A

    2012-07-01

    Methicillin-resistant Staphylococcus aureus (MRSA) from humans can be broadly separated into 3 groups: healthcare-associated (HA), community-associated (CA), and livestock-associated (LA) MRSA. Initially based on epidemiological features, division into these classes is becoming increasingly problematic. The sequencing of S. aureus genomes has highlighted variations in their accessory components, which likely account for differences in pathogenicity and epidemicity. In particular, temperate bacteriophages have been regarded as key players in bacterial pathogenesis. Bacteriophage-associated Panton-Valentine leukocidin genes (luk-PV) are regarded as epidemiological markers of the CA-MRSA due to their high prevalence in CA strains. This paper describes the development and application of a partial composite S. aureus virulence-associated gene microarray. Epidemic, pandemic, and sporadic lineages of UK HA and CA S. aureus were compared. Phage structural genes linked with CA isolates were identified and in silico analysis revealed these to be correlated with phage serogroup. CA strains predominantly carried a PVL-associated phage either of the A or Fb serogroup, whilst HA strains predominantly carried serogroup Fa or B phages. We speculate that carriage of a serogroup A/Fb PVL-associated phage rather than the luk-PV genes specifically is correlated with CA status.

  16. Phenotype switching is a natural consequence of Staphylococcus aureus replication.

    PubMed

    Edwards, Andrew M

    2012-10-01

    The pathogen Staphylococcus aureus undergoes phenotype switching in vivo from its normal colony phenotype (NCP) to a slow-growing, antibiotic-resistant small-colony-variant (SCV) phenotype that is associated with persistence in host cells and tissues. However, it is not clear whether phenotype switching is the result of a constitutive process that is selected for under certain conditions or is triggered by particular environmental stimuli. Examination of cultures of diverse S. aureus strains in the absence of selective pressure consistently revealed a small gentamicin-resistant SCV subpopulation that emerged during exponential-phase NCP growth and increased in number until NCP stationary phase. Treatment of replicating bacteria with the antibiotic gentamicin, which inhibited NCP but not SCV replication, resulted in an initial decrease in SCV numbers, demonstrating that SCVs arise as a consequence of NCP replication. However, SCV population expansion in the presence of gentamicin was reestablished by selection of phenotype-stable SCVs and subsequent SCV replication. In the absence of selective pressure, however, phenotype switching was bidirectional and occurred at a high frequency during NCP replication, resulting in SCV turnover. In summary, these data demonstrate that S. aureus phenotype switching occurs via a constitutive mechanism that generates a dynamic, antibiotic-resistant subpopulation of bacteria that can revert to the parental phenotype. The emergence of SCVs can therefore be considered a normal part of the S. aureus life cycle and provides an insurance policy against exposure to antibiotics that would otherwise eliminate the entire population.

  17. Vaccine protection of leukopenic mice against Staphylococcus aureus bloodstream infection.

    PubMed

    Rauch, Sabine; Gough, Portia; Kim, Hwan Keun; Schneewind, Olaf; Missiakas, Dominique

    2014-11-01

    The risk for Staphylococcus aureus bloodstream infection (BSI) is increased in immunocompromised individuals, including patients with hematologic malignancy and/or chemotherapy. Due to the emergence of antibiotic-resistant strains, designated methicillin-resistant S. aureus (MRSA), staphylococcal BSI in cancer patients is associated with high mortality; however, neither a protective vaccine nor pathogen-specific immunotherapy is currently available. Here, we modeled staphylococcal BSI in leukopenic CD-1 mice that had been treated with cyclophosphamide, a drug for leukemia and lymphoma patients. Cyclophosphamide-treated mice were highly sensitive to S. aureus BSI and developed infectious lesions lacking immune cell infiltrates. Virulence factors of S. aureus that are key for disease establishment in immunocompetent hosts-α-hemolysin (Hla), iron-regulated surface determinants (IsdA and IsdB), coagulase (Coa), and von Willebrand factor binding protein (vWbp)-are dispensable for the pathogenesis of BSI in leukopenic mice. In contrast, sortase A mutants, which cannot assemble surface proteins, display delayed time to death and increased survival in this model. A vaccine with four surface antigens (ClfA, FnBPB, SdrD, and SpAKKAA), which was identified by genetic vaccinology using sortase A mutants, raised antigen-specific immune responses that protected leukopenic mice against staphylococcal BSI.

  18. Vaccine Protection of Leukopenic Mice against Staphylococcus aureus Bloodstream Infection

    PubMed Central

    Rauch, Sabine; Gough, Portia; Kim, Hwan Keun; Schneewind, Olaf

    2014-01-01

    The risk for Staphylococcus aureus bloodstream infection (BSI) is increased in immunocompromised individuals, including patients with hematologic malignancy and/or chemotherapy. Due to the emergence of antibiotic-resistant strains, designated methicillin-resistant S. aureus (MRSA), staphylococcal BSI in cancer patients is associated with high mortality; however, neither a protective vaccine nor pathogen-specific immunotherapy is currently available. Here, we modeled staphylococcal BSI in leukopenic CD-1 mice that had been treated with cyclophosphamide, a drug for leukemia and lymphoma patients. Cyclophosphamide-treated mice were highly sensitive to S. aureus BSI and developed infectious lesions lacking immune cell infiltrates. Virulence factors of S. aureus that are key for disease establishment in immunocompetent hosts—α-hemolysin (Hla), iron-regulated surface determinants (IsdA and IsdB), coagulase (Coa), and von Willebrand factor binding protein (vWbp)—are dispensable for the pathogenesis of BSI in leukopenic mice. In contrast, sortase A mutants, which cannot assemble surface proteins, display delayed time to death and increased survival in this model. A vaccine with four surface antigens (ClfA, FnBPB, SdrD, and SpAKKAA), which was identified by genetic vaccinology using sortase A mutants, raised antigen-specific immune responses that protected leukopenic mice against staphylococcal BSI. PMID:25183728

  19. Anthracimycin Activity Against Contemporary Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Hensler, Mary E.; Jang, Kyoung Hwa; Thienphrapa, Wdee; Vuong, Lisa; Tran, Dan N.; Soubih, Evaristus; Lin, Leo; Haste, Nina M.; Cunningham, Mark L.; Kwan, Bryan P.; Shaw, Karen Joy; Fenical, William; Nizet, Victor

    2014-01-01

    Anthracimycin is a recently discovered novel marine-derived compound with activity against Bacillus anthracis. We tested anthracimycin against an expanded panel of Staphylococcus aureus strains in vitro and in vivo. All strains of S. aureus tested, including methicillin-sensitive (MSSA), methicillin-resistant (MRSA), and vancomycin-resistant strains of S. aureus were sensitive to anthracimycin at minimum inhibitory concentrations (MIC) of < 0.25 mg/L. Although its post-antibiotic effects were minimal, anthracimycin exhibited potent and rapid bactericidal activity, with a > 4-log kill of USA300 MRSA within 3 hours at 5 times its MIC. At concentrations significantly below the MIC, anthracimycin slowed MRSA growth and potentiated the bactericidal activity of the human cathelicidin, LL-37. The bactericidal activity of anthracimycin was somewhat mitigated in the presence of 20% human serum, and the compound was minimally toxic to human cells, with an IC50 = 70 mg/L against human carcinoma cells. At concentrations near the MIC anthracimycin inhibited S. aureus nucleic acid synthesis as determined by optimized macromolecular synthesis methodology, with inhibition of DNA and RNA synthesis occurring in the absence of DNA intercalation. Anthracimycin at a single dose of 1 or 10 mg/kg was able to protect mice from MRSA-induced mortality in a murine peritonitis model of infection. Anthracimycin provides an interesting new scaffold for future development of a novel MRSA antibiotic. PMID:24736856

  20. Antibacterial activity of alimentary plants against Staphylococcus aureus growth.

    PubMed

    Pérez, C; Anesini, C

    1994-01-01

    Alimentary plants were screened for antibacterial activity against a penicillin G resistant strain of Staphylococcus aureus. Twenty-five samples of plant material corresponding to 21 species from 13 families were used. Both aqueous and ethanol extracts were obtained from them. Antibacterial activity was determined by the agar-well diffusion method, using cephazolin as a standard antibiotic. Seventeen ethanol extracts were found active. Eugenia caryophyllata (clavo de olor*) flowers, Myristica fragans (nuez moscada*) seeds, Theobroma cacao (cacao*) seed bark, Triticum sp (trigo*) fruit, Zea mays (maíz*) fruit and Piper nigrum (pimienta*) ripe fruit produced some of the more active extracts (* = Argentine vulgar names).

  1. Staphylococcus aureus promoter-lux reporters for drug discovery.

    PubMed

    Mesak, Lili R; Qi, Shuhua; Villanueva, Ivan; Miao, Vivian; Davies, Julian

    2010-08-01

    We describe a collection of antibiotic-activated Staphylococcus aureus promoter-lux reporter strains that can be used to discriminate among antibiotic classes on the basis of their light production response profile. We screened over 400 culture supernatants from previously uncharacterized actinomycetes from soil for the production of aminocoumarin-type compounds and DNA-damaging agents. Novobiocin production was determined in three isolates of Streptomyces, and streptonigrin, a DNA-damaging agent, together with several other bioactive compounds (oxopropaline D and G), was identified from a novel Kitasatospora isolate. This array provides an effective and specific whole-cell approach to search for classes of antimicrobial compounds in unfractionated culture broths.

  2. Molecular mechanisms of methicillin resistance in Staphylococcus aureus.

    PubMed

    Domínguez, M A; Liñares, J; Martín, R

    1997-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most common nosocomial pathogens. The most significant mechanism of resistance to methicillin in this-species is the acquisition of a genetic determinant (mecA gene). However, resistance seems to have a more complex molecular basis, since additional chromosomal material is involved in such resistance. Besides, overproduction of penicillinase and/or alterations in the PBPs can contribute to the formation of resistance phenotypes. Genetic and environmental factors leading to MRSA are reviewed.

  3. Cataract surgery during active methicillin-resistant Staphylococcus aureus infection.

    PubMed

    Mansour, Ahmad M; Salti, Haytham I

    2014-01-01

    We present two patients with active, foul-smelling, methicillin-resistant Staphylococcus aureus (MRSA) wounds of the forehead and sternum following craniotomy or open heart surgery. Both had debilitating cataracts and were told by the infectious diseases team that cataract surgery is very risky. Both underwent sequential bilateral phacoemulsification with no sign of infection. Patients with active MRSA wound infections may safely undergo cataract surgery with additional precautions observed intraoperatively (good wound construction) and postoperatively (topical antibiotics and close observation). Banning such surgeries can unnecessarily jeopardize the lifestyles of such patients.

  4. Effects of streptomycin and novobiocin on Staphylococcus aureus gene expression.

    PubMed Central

    Nordström, K; Lindberg, M

    1978-01-01

    Streptomycin and novobiocin induced production of protein A and inhibited production of alpha- and beta-hemolysins in mutants of Staphylococcus aureus strains RN450 and RN1 resistant to these antibiotics. Streptomycin, but not novobiocin, also inhibited propagation of bacteriophages of serological group B, whereas phages of group A were unaffected. Streptomycin had to be present at adsorption of the phage, and 10 mM CACL2 reversed the inhibitory effect. Lysogenization and competence induction occurred in the presence of streptomycin, suggesting that some early phage genes were expressed. PMID:627534

  5. Cutaneous myiasis masquerading as methicillin-resistant Staphylococcus aureus.

    PubMed

    Lopez, Jonathan J; Coris, Eric E

    2013-09-01

    Numerous factors place athletes at increased risk for cutaneous infections, and as such, they are a common complaint in athletic training rooms. Methicillin-resistant Staphylococcus aureus (MRSA) is an increasingly common etiology, and given its severe sequelae, a high index of suspicion in this population is justified. We present 2 cases of college athletes who presented to the athletic training room with findings suspicious for MRSA infection. However, after further investigation, the true diagnosis of myiasis was reached. These cases highlight the importance of asking athletes about recent travel and considering a broad differential diagnosis when evaluating furuncular lesions.

  6. Repurposing Ivacaftor for treatment of Staphylococcus aureus infections.

    PubMed

    Thakare, Ritesh; Singh, Alok Kumar; Das, Swetarka; Vasudevan, N; Jachak, Gorakhnath R; Reddy, D Srinivasa; Dasgupta, Arunava; Chopra, Sidharth

    2017-09-01

    Drug repurposing of non-antimicrobials is a novel method to augment a seriously depleted drug pipeline for targeting drug-resistant pathogens. This article highlights the potent antimicrobial activity of Ivacaftor against Staphylococcus aureus, including vancomycin- and other multidrug-resistant strains. The potent activity of Ivacaftor in vivo is also demonstrated in a murine neutropenic thigh infection model. Taken together, these results support the potential of Ivacaftor as an antimicrobial agent for the treatment of staphylococcal infections. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  7. Inhibition of methicillin resistant Staphylococcus aureus by a plasma needle

    NASA Astrophysics Data System (ADS)

    Miletić, Maja; Vuković, Dragana; Živanović, Irena; Dakić, Ivana; Soldatović, Ivan; Maletić, Dejan; Lazović, Saša; Malović, Gordana; Petrović, Zoran; Puač, Nevena

    2014-03-01

    In numerous recent papers plasma chemistry of non equilibrium plasma sources operating at atmospheric pressure has been linked to plasma medical effects including sterilization. In this paper we present a study of the effectiveness of an atmospheric pressure plasma source, known as plasma needle, in inhibition of the growth of biofilm produced by methicillin resistant Staphylococcus aureus (MRSA). Even at the lowest powers the biofilms formed by inoculi of MRSA of 104 and 105 CFU have been strongly affected by plasma and growth in biofilms was inhibited. The eradication of the already formed biofilm was not achieved and it is required to go to more effective sources.

  8. [Cats and dogs as a reservoir for Staphylococcus aureus].

    PubMed

    Bierowiec, Karolina; Płoneczka-Janeczko, Katarzyna; Rypuła, Krzysztof

    2014-08-18

    For many years, Staphylococcus aureus MRSA was thought to happen only in humans. It has now become an increasingly urgent problem in veterinary medicine, with MRSA infections reported in pets as well as farm animals. The animals may be contaminated, colonized or infected with MSSA as well as MRSA strains. Pets are a potential reservoir for human infection. Transmission of such pathogen occurs between pets, owners and veterinary staff. This is why, is need to generate data regarding both the levels of carriage of such bacteria in pets and the risk factors associated with the transfer of the bacteria to humans, who have a contact with infected pets.

  9. Targeting Staphylococcus aureus Quorum Sensing with Nonpeptidic Small Molecule Inhibitors

    PubMed Central

    2014-01-01

    A series of 3-oxo-C12-HSL, tetramic acid, and tetronic acid analogues were synthesized to gain insights into the structural requirements for quorum sensing inhibition in Staphylococcus aureus. Compounds active against agr were noncompetitive inhibitors of the autoinducing peptide (AIP) activated AgrC receptor, by altering the activation efficacy of the cognate AIP-1. They appeared to act as negative allosteric modulators and are exemplified by 3-tetradecanoyltetronic acid 17, which reduced nasal cell colonization and arthritis in a murine infection model. PMID:24592914

  10. Blood–Retinal Barrier Compromise and Endogenous Staphylococcus aureus Endophthalmitis

    PubMed Central

    Coburn, Phillip S.; Wiskur, Brandt J.; Astley, Roger A.; Callegan, Michelle C.

    2015-01-01

    Purpose To test the hypothesis that blood–retinal barrier compromise is associated with the development of endogenous Staphylococcus aureus endophthalmitis. Methods To compromise the blood–retinal barrier in vivo, streptozotocin-induced diabetes was induced in C57BL/6J mice for 1, 3, or 5 months. Diabetic and age-matched nondiabetic mice were intravenously injected with 108 colony-forming units (cfu) of S. aureus, a common cause of endogenous endophthalmitis in diabetics. After 4 days post infection, electroretinography, histology, and bacterial counts were performed. Staphylococcus aureus–induced alterations in in vitro retinal pigment epithelial (RPE) cell barrier structure and function were assessed by anti–ZO-1 immunohistochemistry, FITC-dextran conjugate diffusion, and bacterial transmigration assays. Results We observed one bilateral infection in a control, nondiabetic animal (mean = 1.54 × 103 ± 1.78 × 102 cfu/eye, 7% incidence). Among the 1-month diabetic mice, we observed culture-confirmed unilateral infections in two animals (mean = 5.54 × 102 ± 7.09 × 102 cfu/eye, 12% incidence). Among the 3-month diabetic mice, infections were observed in 11 animals, three with bilateral infections (mean = 2.67 × 102 ± 2.49 × 102 cfu/eye, 58% incidence). Among the 5-month diabetic mice, we observed infections in five animals (mean = 7.88 × 102 ± 1.08 × 103 cfu/eye, 33% incidence). In vitro, S. aureus infection reduced ZO-1 immunostaining and disrupted the barrier function of cultured RPE cells, resulting in diffusion of fluorophore-conjugated dextrans and transmigration of live bacteria across a permeabilized RPE barrier. Conclusions Taken together, these results indicated that S. aureus is capable of inducing blood–retinal barrier permeability and causing endogenous bacterial endophthalmitis in normal and diabetic animals. PMID:26559476

  11. Daptomycin-nonsusceptible, vancomycin-intermediate, methicillin-resistant Staphylococcus aureus endocarditis

    PubMed Central

    Yu, Ryan; Dale, Suzanne E; Yamamura, Deborah; Stankus, Vida; Lee, Christine

    2012-01-01

    Due to the emergence of Staphylococcus aureus with reduced vancomycin susceptibility, newer antibiotics, including daptomycin, have been used to treat methicillin-resistant S aureus infections. Daptomycin is a cyclic lipopeptide that is approved to treat S aureus bacteremia and right-sided endocarditis, and reports of S aureus with reduced susceptibility to daptomycin are infrequent. To our knowledge, the present report describes the first Canadian case of daptomycin-nonsusceptible, vancomycin-intermediate S aureus infection. PMID:23730321

  12. Draft Genome Sequence of Isolate Staphylococcus aureus LHSKBClinical, Isolated from an Infected Hip

    PubMed Central

    Stipetic, Laurence H.; Hamilton, Graham; Dalby, Matthew J.; Davies, Robert L.; Meek, R. M. Dominic; Ramage, Gordon; Smith, David G. E.

    2015-01-01

    We report here the genome sequence of a clinical isolate of Staphylococcus aureus from an orthopedic infection. Phenotypically diverse Staphylococcus aureus strains are associated with orthopedic infections and subsequent implant failure, and some are highly resistant to antibiotics. This genome sequence will support further analyses of strains causing orthopedic infections. PMID:25931597

  13. Community-Acquired Methicillin-Resistant "Staphylococcus aureus": Considerations for School Nurses

    ERIC Educational Resources Information Center

    Alex, Aniltta; Letizia, MariJo

    2007-01-01

    Methicillin-resistant "Staphylococcus aureus" (MRSA) is a disease-causing organism that has been present in hospital settings since the 1960s. However, a genetically distinct strain of MRSA, called community-acquired methicillin-resistant "Staphylococcus aureus" (CA-MRSA), has emerged in recent years in community settings among healthy…

  14. Community-Acquired Methicillin-Resistant "Staphylococcus aureus": Considerations for School Nurses

    ERIC Educational Resources Information Center

    Alex, Aniltta; Letizia, MariJo

    2007-01-01

    Methicillin-resistant "Staphylococcus aureus" (MRSA) is a disease-causing organism that has been present in hospital settings since the 1960s. However, a genetically distinct strain of MRSA, called community-acquired methicillin-resistant "Staphylococcus aureus" (CA-MRSA), has emerged in recent years in community settings among healthy…

  15. Community-acquired methicillin-resistant Staphylococcus aureus: an emerging cause of acute bacterial parotitis.

    PubMed

    Nicolasora, Nelson P; Zacharek, Mark A; Malani, Anurag N

    2009-02-01

    Staphylococcus aureus has long been recognized as a cause of acute bacterial parotitis. A case of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) parotitis is presented, highlighting the emergence of this increasingly important pathogen to cause a wide variety of infections. Also reviewed are the salient clinical and microbiologic features of this novel infection.

  16. Staphylococcus aureus and Staphylococcus epidermidis Virulence Strains as Causative Agents of Persistent Infections in Breast Implants.

    PubMed

    Chessa, Daniela; Ganau, Giulia; Spiga, Luisella; Bulla, Antonio; Mazzarello, Vittorio; Campus, Gian Vittorio; Rubino, Salvatore

    2016-01-01

    Staphylococcus epidermidis and Staphylococcus aureus are currently considered two of the most important pathogens in nosocomial infections associated with catheters and other medical implants and are also the main contaminants of medical instruments. However because these species of Staphylococcus are part of the normal bacterial flora of human skin and mucosal surfaces, it is difficult to discern when a microbial isolate is the cause of infection or is detected on samples as a consequence of contamination. Rapid identification of invasive strains of Staphylococcus infections is crucial for correctly diagnosing and treating infections. The aim of the present study was to identify specific genes to distinguish between invasive and contaminating S. epidermidis and S. aureus strains isolated on medical devices; the majority of our samples were collected from breast prostheses. As a first step, we compared the adhesion ability of these samples with their efficacy in forming biofilms; second, we explored whether it is possible to determine if isolated pathogens were more virulent compared with international controls. In addition, this work may provide additional information on these pathogens, which are traditionally considered harmful bacteria in humans, and may increase our knowledge of virulence factors for these types of infections.

  17. Staphylococcus aureus and Staphylococcus epidermidis Virulence Strains as Causative Agents of Persistent Infections in Breast Implants

    PubMed Central

    Chessa, Daniela; Ganau, Giulia; Spiga, Luisella; Bulla, Antonio; Mazzarello, Vittorio; Campus, Gian Vittorio; Rubino, Salvatore

    2016-01-01

    Staphylococcus epidermidis and Staphylococcus aureus are currently considered two of the most important pathogens in nosocomial infections associated with catheters and other medical implants and are also the main contaminants of medical instruments. However because these species of Staphylococcus are part of the normal bacterial flora of human skin and mucosal surfaces, it is difficult to discern when a microbial isolate is the cause of infection or is detected on samples as a consequence of contamination. Rapid identification of invasive strains of Staphylococcus infections is crucial for correctly diagnosing and treating infections. The aim of the present study was to identify specific genes to distinguish between invasive and contaminating S. epidermidis and S. aureus strains isolated on medical devices; the majority of our samples were collected from breast prostheses. As a first step, we compared the adhesion ability of these samples with their efficacy in forming biofilms; second, we explored whether it is possible to determine if isolated pathogens were more virulent compared with international controls. In addition, this work may provide additional information on these pathogens, which are traditionally considered harmful bacteria in humans, and may increase our knowledge of virulence factors for these types of infections. PMID:26811915

  18. Response of Staphylococcus Aureus to a Spaceflight Analogue

    NASA Technical Reports Server (NTRS)

    Castro, S. L.; Ott, C. M.

    2010-01-01

    The decreased gravity of the spaceflight environment creates quiescent, low fluid shear conditions. This environment can impart considerable effects on the physiology of microorganisms as well as their interactions with potential hosts. Using the rotating wall vessel (RWV), as a spaceflight analogue, the consequence of low fluid shear culture on microbial pathogenesis has provided a better understanding of the risks to the astronaut crew from infectious microorganisms. While the outcome of low fluid shear culture has been investigated for several bacterial pathogens, little has been done to understand how this environmental factor affects Staphylococcus aureus. S. aureus is an opportunistic human pathogen which presents a high level of infection risk to the crew, as it has been isolated from both the space shuttle and International Space Station. Given that approximately forty percent of the population are carriers of the bacteria, eradication of this organism from in flight environments is impractical. These reasons have lead to us to assess the response of S. aureus to a reduced fluid shear environment. Culture in the RWV demonstrated that S. aureus grown under the low-shear condition had lower cell concentrations after 10 hours when compared to the control culture. Furthermore, the low-shear cultured bacteria displayed a reduction in carotenoid production, pigments responsible for their yellow/gold coloration. When exposed to various environmental stressors, post low-shear culture, a decrease in the ability to survive oxidative assault was observed compared to control cultures. The low fluid shear environment also resulted in a decrease in hemolysin secretion, a staphylococcal toxin responsible for red blood cell lysis. When challenged by the immune components present in human whole blood, low-shear cultured S. aureus demonstrated significantly reduced survival rates as compared to the control culture. Assays to determine the duration of these alterations

  19. Response of Staphylococcus Aureus to a Spaceflight Analogue

    NASA Technical Reports Server (NTRS)

    Castro, S. L.; Ott, C. M.

    2010-01-01

    The decreased gravity of the spaceflight environment creates quiescent, low fluid shear conditions. This environment can impart considerable effects on the physiology of microorganisms as well as their interactions with potential hosts. Using the rotating wall vessel (RWV), as a spaceflight analogue, the consequence of low fluid shear culture on microbial pathogenesis has provided a better understanding of the risks to the astronaut crew from infectious microorganisms. While the outcome of low fluid shear culture has been investigated for several bacterial pathogens, little has been done to understand how this environmental factor affects Staphylococcus aureus. S. aureus is an opportunistic human pathogen which presents a high level of infection risk to the crew, as it has been isolated from both the space shuttle and International Space Station. Given that approximately forty percent of the population are carriers of the bacteria, eradication of this organism from in flight environments is impractical. These reasons have lead to us to assess the response of S. aureus to a reduced fluid shear environment. Culture in the RWV demonstrated that S. aureus grown under the low-shear condition had lower cell concentrations after 10 hours when compared to the control culture. Furthermore, the low-shear cultured bacteria displayed a reduction in carotenoid production, pigments responsible for their yellow/gold coloration. When exposed to various environmental stressors, post low-shear culture, a decrease in the ability to survive oxidative assault was observed compared to control cultures. The low fluid shear environment also resulted in a decrease in hemolysin secretion, a staphylococcal toxin responsible for red blood cell lysis. When challenged by the immune components present in human whole blood, low-shear cultured S. aureus demonstrated significantly reduced survival rates as compared to the control culture. Assays to determine the duration of these alterations

  20. Effect of Substance P in Staphylococcus aureus and Staphylococcus epidermidis Virulence: Implication for Skin Homeostasis

    PubMed Central

    N'Diaye, Awa; Mijouin, Lily; Hillion, Mélanie; Diaz, Suraya; Konto-Ghiorghi, Yoan; Percoco, Giuseppe; Chevalier, Sylvie; Lefeuvre, Luc; Harmer, Nicholas J.; Lesouhaitier, Olivier; Feuilloley, Marc G. J.

    2016-01-01

    Staphylococcus aureus and Staphylococcus epidermidis are two major skin associated bacteria, and Substance P (SP) is a major skin neuropeptide. Since bacteria are known to sense and response to many human hormones, we investigated the effects of SP on Staphylococci virulence in reconstructed human epidermis model and HaCaT keratinocytes. We show that SP is stimulating the virulence of S. aureus and S. epidermidis in a reconstructed human epidermis model. qRT-PCR array analysis of 64 genes expressed by keratinocytes in the response to bacterial infection revealed a potential link between the action of SP on Staphylococci and skin physiopathology. qRT-PCR and direct assay of cathelicidin and human β-defensin 2 secretion also provided that demonstration that the action of SP on bacteria is independent of antimicrobial peptide expression by keratinocytes. Considering an effect of SP on S. aureus and S. epidermidis, we observed that SP increases the adhesion potential of both bacteria on keratinocytes. However, SP modulates the virulence of S. aureus and S. epidermidis through different mechanisms. The response of S. aureus is associated with an increase in Staphylococcal Enterotoxin C2 (SEC2) production and a reduction of exolipase processing whereas in S. epidermidis the effect of SP appears mediated by a rise in biofilm formation activity. The Thermo unstable ribosomal Elongation factor Ef-Tu was identified as the SP-interacting protein in S. aureus and S. epidermidis. SP appears as an inter-kingdom communication factor involved in the regulation of bacterial virulence and essential for skin microflora homeostasis. PMID:27148195

  1. Effect of Substance P in Staphylococcus aureus and Staphylococcus epidermidis Virulence: Implication for Skin Homeostasis.

    PubMed

    N'Diaye, Awa; Mijouin, Lily; Hillion, Mélanie; Diaz, Suraya; Konto-Ghiorghi, Yoan; Percoco, Giuseppe; Chevalier, Sylvie; Lefeuvre, Luc; Harmer, Nicholas J; Lesouhaitier, Olivier; Feuilloley, Marc G J

    2016-01-01

    Staphylococcus aureus and Staphylococcus epidermidis are two major skin associated bacteria, and Substance P (SP) is a major skin neuropeptide. Since bacteria are known to sense and response to many human hormones, we investigated the effects of SP on Staphylococci virulence in reconstructed human epidermis model and HaCaT keratinocytes. We show that SP is stimulating the virulence of S. aureus and S. epidermidis in a reconstructed human epidermis model. qRT-PCR array analysis of 64 genes expressed by keratinocytes in the response to bacterial infection revealed a potential link between the action of SP on Staphylococci and skin physiopathology. qRT-PCR and direct assay of cathelicidin and human β-defensin 2 secretion also provided that demonstration that the action of SP on bacteria is independent of antimicrobial peptide expression by keratinocytes. Considering an effect of SP on S. aureus and S. epidermidis, we observed that SP increases the adhesion potential of both bacteria on keratinocytes. However, SP modulates the virulence of S. aureus and S. epidermidis through different mechanisms. The response of S. aureus is associated with an increase in Staphylococcal Enterotoxin C2 (SEC2) production and a reduction of exolipase processing whereas in S. epidermidis the effect of SP appears mediated by a rise in biofilm formation activity. The Thermo unstable ribosomal Elongation factor Ef-Tu was identified as the SP-interacting protein in S. aureus and S. epidermidis. SP appears as an inter-kingdom communication factor involved in the regulation of bacterial virulence and essential for skin microflora homeostasis.

  2. Staphylococcus pseudintermedius expresses surface proteins that closely resemble those from Staphylococcus aureus.

    PubMed

    Geoghegan, Joan A; Smith, Emma J; Speziale, Pietro; Foster, Timothy J

    2009-09-18

    Staphylococcus pseudintermedius is a commensal of dogs that is implicated in the pathogenesis of canine pyoderma. This study aimed to determine if S. pseudintermedius expresses surface proteins resembling those from Staphylococcus aureus and to characterise them. S. pseudintermedius strain 326 was shown to adhere strongly to purified fibrinogen, fibronectin and cytokeratin 10. It adhered to the alpha-chain of fibrinogen which, along with binding to cytokeratin 10, is the hallmark of clumping factor B of S. aureus, a surface protein that is in part responsible for colonisation of the human nares. Ligand-affinity blotting with cell-wall extracts demonstrated that S. pseudintermedius 326 expressed a cell-wall anchored fibronectin binding protein which recognised the N-terminal 29kDa fragment. The ability to bind fibronectin is an important attribute of pathogenic S. aureus and is associated with the ability of S. aureus to colonise skin of human atopic dermatitis patients. S. pseudintermedius genomic DNA was probed with labelled DNA amplified from the serine-aspartate repeat encoding region of clfA of S. aureus. This probe hybridised to a single SpeI fragment of S. pseudintermedius DNA. In the cell-wall extract of S. pseudintermedius 326, a 180kDa protein was discovered which bound to fibrinogen by ligand-affinity blotting and reacted in a Western blot with antibodies raised against the serine-aspartate repeat region of ClfA and the B-repeats of SdrD of S. aureus. It is proposed that this is an Sdr protein with B-repeats that has an A domain that binds to fibrinogen. Whether it is the same protein that binds cytokeratin 10 is not clear.

  3. Staphylococcus aureus and Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) in and Around Therapeutic Whirlpools in College Athletic Training Rooms

    PubMed Central

    Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A.

    2015-01-01

    Context: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. Objective: To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Design: Cross-sectional study. Setting: National Collegiate Athletic Association Division I university. Patients or Other Participants: Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Main Outcome Measure(s): Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. Results: We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F2,238 = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Conclusions: Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses. PMID:25710853

  4. Methicillin-resistant Staphylococcus aureus in palliative care: A prospective study of Methicillin-resistant Staphylococcus aureus prevalence in a hospital-based palliative care unit.

    PubMed

    Schmalz, Oliver; Strapatsas, Tobias; Alefelder, Christof; Grebe, Scott Oliver

    2016-07-01

    Methicillin-resistant Staphylococcus aureus is a common organism in hospitals worldwide and is associated with morbidity and mortality. However, little is known about the prevalence in palliative care patients. Furthermore, there is no standardized screening protocol or treatment for patients for whom therapy concentrates on symptom control. Examining the prevalence of methicillin-resistant Staphylococcus aureus in palliative care patients as well as the level of morbidity and mortality. We performed a prospective study where methicillin-resistant Staphylococcus aureus screening was undertaken in 296 consecutive patients within 48 h after admission to our palliative care unit. Medical history was taken, clinical examination was performed, and the Karnofsky Performance Scale and Palliative Prognostic Score were determined. Prevalence of Methicillin-resistant Staphylococcus aureus was compared to data of general hospital patients. In total, 281 patients were included in the study having a mean age of 69.7 years (standard deviation = 12.9 years) and an average Karnofsky Performance Scale between 30% and 40%. The mean length of stay was 9.7 days (standard deviation = 7.6 days). A total of 24 patients were methicillin-resistant Staphylococcus aureus positive on the first swab. Median number of swabs was 2. All patients with a negative methicillin-resistant Staphylococcus aureus swab upon admission remained Methicillin-resistant Staphylococcus aureus negative in all subsequent swabs. Our study suggests that the prevalence of Methicillin-resistant Staphylococcus aureus among patients in an in-hospital palliative care unit is much higher than in other patient populations. © The Author(s) 2016.

  5. Staphylococcus aureus and community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in and around therapeutic whirlpools in college athletic training rooms.

    PubMed

    Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A

    2015-04-01

    Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Cross-sectional study. National Collegiate Athletic Association Division I university. Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F(2,238) = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses.

  6. [Detection of Staphylococcus aureus, Shigella spp., Salmonella spp. in food by multiplex PCR].

    PubMed

    Li, Bo; Chen, Fusheng; Wang, Xiaohong; Shao, Yanchun

    2008-07-01

    To establish a multiplex PCR method for simultaneous detection of Staphylococcus aureus, Shigella spp., Salmonella spp. in food. Staphylococcus aureus was enriched by 7.5% NaCl broth while Shigella spp. and Salmonella spp. were enriched by GN medium . The primers were designed according to the gene nuc of Staphylococcus aureus, the gene ipaH of Shigella spp. and the gene invA of Salmonella spp. The target genes of these pathogens in food were amplified by multiplex PCR, which reaction conditions were optimized specifically. The multiplex PCR method established in this experment was of high specificity, which detection limit was 1 cfu/ml of Staphylococcus aureus, Shigella spp. and Salmonella spp. when the milk samples contaminated with these pathogens. The multiplex PCR method, which was rapid, convenient, and with high sensitivity, could be suitable for rapid detection of Staphylococcus aureus, Shigella spp., Salmonella spp. in food, and could have a great prospect.

  7. Heme Recognition By a Staphylococcus Aureus IsdE

    SciTech Connect

    Grigg, J.C.; Vermeiren, C.L.; Heinrichs, D.E.; Murphy, M.E.P.

    2009-06-03

    Staphylococcus aureus is a Gram-positive bacterial pathogen and a leading cause of hospital acquired infections. Because the free iron concentration in the human body is too low to support growth, S. aureus must acquire iron from host sources. Heme iron is the most prevalent iron reservoir in the human body and a predominant source of iron for S. aureus. The iron-regulated surface determinant (Isd) system removes heme from host heme proteins and transfers it to IsdE, the cognate substrate-binding lipoprotein of an ATP-binding cassette transporter, for import and subsequent degradation. Herein, we report the crystal structure of the soluble portion of the IsdE lipoprotein in complex with heme. The structure reveals a bi-lobed topology formed by an N- and C-terminal domain bridged by a single {alpha}-helix. The structure places IsdE as a member of the helical backbone metal receptor superfamily. A six-coordinate heme molecule is bound in the groove established at the domain interface, and the heme iron is coordinated in a novel fashion for heme transporters by Met{sup 78} and His{sup 229}. Both heme propionate groups are secured by H-bonds to IsdE main chain and side chain groups. Of these residues, His{sup 299} is essential for IsdE-mediated heme uptake by S. aureus when growth on heme as a sole iron source is measured. Multiple sequence alignments of homologues from several other Gram-positive bacteria, including the human pathogens pyogenes, Bacillus anthracis, and Listeria monocytogenes, suggest that these other systems function equivalently to S. aureus IsdE with respect to heme binding and transport.

  8. Antimicrobial susceptibility of Staphylococcus aureus from retail ground meats.

    PubMed

    Kelman, Alina; Soong, Yee-Ann; Dupuy, Nicole; Shafer, Daniel; Richbourg, William; Johnson, Kourtney; Brown, Twain; Kestler, Edward; Li, Yi; Zheng, Jie; McDermott, Patrick; Meng, Jianghong

    2011-10-01

    The aim of this study was to characterize antimicrobial resistance in Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), recovered from raw retail meat products purchased in the Washington, D.C., area. From March to August 2008, 694 samples of ground beef (n = 198), ground pork (n = 300), and ground turkey (n = 196) were collected by random sampling from stores of three grocery chains. In total, 200 S. aureus isolates (29%) were recovered by direct plating. When tested for susceptibility to 22 antimicrobials, 69% of the S. aureus isolates were resistant to tetracycline, 26% to penicillin, 17% to ampicillin, 13% to methicillin, 8% to erythromycin, 4.5% to clindamycin, 1.5% to gentamicin, and 0.5% to chloramphenicol, oxacillin, cefoxitin, or quinupristin-dalfopristin. However, 27% of the isolates were susceptible to all tested antimicrobials. More turkey and pork isolates were resistant to ampicillin, penicillin, and tetracycline than were beef isolates (P < 0.05). Additionally, 17% of the turkey and 17% of the pork isolates were resistant to methicillin (MIC ≥ 16 μg/ml), whereas no beef isolates were resistant to the antimicrobial agent. A single MRSA (methicillin MIC > 32 μg/ml) isolate containing the mecA gene with additional resistance to erythromycin, clindamycin, oxacillin plus 2% NaCl, cefoxitin, ampicillin, penicillin, quinupristin-dalfopristin, tetracycline, and gentamicin was recovered from one pork sample. The presence of antimicrobial-resistant S. aureus, coupled with the relative lack of such studies in the United States, suggests that further investigations on MRSA in the food supply are needed despite the low rate of MRSA found in this particular study.

  9. Growth kinetics of Staphylococcus aureus on Brie and Camembert cheeses.

    PubMed

    Lee, Heeyoung; Kim, Kyungmi; Lee, Soomin; Han, Minkyung; Yoon, Yohan

    2014-05-01

    In this study, we developed mathematical models to describe the growth kinetics of Staphylococcus aureus on natural cheeses. A five-strain mixture of Staph. aureus was inoculated onto 15 g of Brie and Camembert cheeses at 4 log CFU/g. The samples were then stored at 4, 10, 15, 25, and 30 °C for 2-60 d, with a different storage time being used for each temperature. Total bacterial and Staph. aureus cells were enumerated on tryptic soy agar and mannitol salt agar, respectively. The Baranyi model was fitted to the growth data of Staph. aureus to calculate kinetic parameters such as the maximum growth rate in log CFU units (r max; log CFU/g/h) and the lag phase duration (λ; h). The effects of temperature on the square root of r max and on the natural logarithm of λ were modelled in the second stage (secondary model). Independent experimental data (observed data) were compared with prediction and the respective root mean square error compared with the RMSE of the fit on the original data, as a measure of model performance. The total growth of bacteria was observed at 10, 15, 25, and 30 °C on both cheeses. The r max values increased with storage temperature (P<0·05), but a significant effect of storage temperature on λ values was only observed between 4 and 15 °C (P<0·05). The square root model and linear equation were found to be appropriate for description of the effect of storage temperature on growth kinetics (R 2=0·894-0·983). Our results indicate that the models developed in this study should be useful for describing the growth kinetics of Staph. aureus on Brie and Camembert cheeses.

  10. Molecular characterization of α-amylase from Staphylococcus aureus.

    PubMed

    Lakshmi, Hanumanthu Prasanna; Prasad, Uppu Venkateswara; Yeswanth, Sthanikam; Swarupa, Vimjam; Prasad, Osuru Hari; Narasu, Mangamoori Lakshmi; Sarma, Potukuchi Venkata Gurunadha Krishna

    2013-01-01

    Staphylococcus aureus is one of the prominent Gram positive human pathogen secretes many surface and secretary proteins including various enzymes and pathogenic factors that favour the successful colonization and infection of host tissue. α-amylase is one of the enzymes secreted by S. aureus which catalyses the breakdown of complex sugars to monosaccharides, which are required for colonization and survival of this pathogen in any anatomical locales. In the present study we have cloned, sequenced, expressed and characterized α-amylase gene from S. aureus ATCC12600. The recombinant enzyme has a molecular weight of 58kDa and the kinetics showed Vmax 0.0208±0.033 (mg/ml)/mg/min and Km 10.633±0.737mg/ml. The multiple sequence analysis showed α- amylase of S. aureus exhibited large differences with Bacillus subtilis and Streptococcus bovis. As the crystal structure of S. aureus α- amylase was unavailable, we used homology modelling method to build the structure. The built structure was validated by Ramachandran plot which showed 90% of the residues in the allowed region while no residue was found in the disallowed region and the built structure was close to the crystal structure with Z-Score: -6.85. The structural superimposition studies with α- amylases of Bacillus subtilis and Streptococcus bovis showed distinct differences with RMSD values of 18.158Åand 7.091Å respectively which correlated with enzyme kinetics, indicating α-amylase is different among these bacteria.

  11. Staphylococcus aureus ST398 from slaughter pigs in northeast China.

    PubMed

    Yan, Xiaomei; Yu, Xiaojie; Tao, Xiaoxia; Zhang, Jianfeng; Zhang, Binghua; Dong, Rui; Xue, Chengyu; Grundmann, Hajo; Zhang, Jianzhong

    2014-05-01

    To describe the prevalence and population structure of Staphylococcus aureus bacteria that colonize pigs at slaughterhouses in northeastern China, nose swabs were collected from pigs in two slaughterhouses in Harbin, Heilongjiang Province, China in 2009. S. aureus isolates were characterized by multilocus sequence typing (MLST), spa typing, SCCmec typing, antimicrobial susceptibility testing and pvl gene detection. A total of 200 S. aureus isolates were collected from 590 pigs (33.9%, 200/590), of which 162 (81%, 162/200) were methicillin-susceptible S. aureus (MSSA) and 38 (19%, 38/200) were methicillin-resistant S. aureus (MRSA). Ninety-nine of the MSSA isolates (99/162, 61.1%) were ST398, which represented the dominant sequence type overall. Eighty-seven isolates were ST9 (87/200, 43.5%), and all MRSA belonged to that sequence type which consisted of the spa types t899 and t2922. Among the MSSA strains, t034, t899 and t4358 were the most dominant spa types (139/162, 85.8%). All MRSA isolates harbored SCCmec type IVb. The pvl gene was only detected in 3 ST7/t2119 MSSA isolates. All MRSA but more importantly also 82.7% (134/162) of the MSSA isolates were resistant to six or more antibiotics. Moreover, a novel resistance determinant-lsa(E) was identified among 22% (44/200) of all isolates. In conclusion, pigs in northeast China are frequently colonized with ST398 MSSA. MRSA with this sequence type, typically associated with pigs in Europe, was not found. High levels of multiple antibiotic resistance among MRSA isolates as well as MSSA isolates are a public health concern.

  12. Susceptibility patterns of Staphylococcus aureus biofilms in diabetic foot infections.

    PubMed

    Mottola, Carla; Matias, Carina S; Mendes, João J; Melo-Cristino, José; Tavares, Luís; Cavaco-Silva, Patrícia; Oliveira, Manuela

    2016-06-23

    Foot infections are a major cause of morbidity in people with diabetes and the most common cause of diabetes-related hospitalization and lower extremity amputation. Staphylococcus aureus is by far the most frequent species isolated from these infections. In particular, methicillin-resistant S. aureus (MRSA) has emerged as a major clinical and epidemiological problem in hospitals. MRSA strains have the ability to be resistant to most β-lactam antibiotics, but also to a wide range of other antimicrobials, making infections difficult to manage and very costly to treat. To date, there are two fifth-generation cephalosporins generally efficacious against MRSA, ceftaroline and ceftobripole, sharing a similar spectrum. Biofilm formation is one of the most important virulence traits of S. aureus. Biofilm growth plays an important role during infection by providing defence against several antagonistic mechanisms. In this study, we analysed the antimicrobial susceptibility patterns of biofilm-producing S. aureus strains isolated from diabetic foot infections. The antibiotic minimum inhibitory concentration (MIC) was determined for ten antimicrobial compounds, along with the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC), followed by PCR identification of genetic determinants of biofilm production and antimicrobial resistance. Results demonstrate that very high concentrations of the most used antibiotics in treating diabetic foot infections (DFI) are required to inhibit S. aureus biofilms in vitro, which may explain why monotherapy with these agents frequently fails to eradicate biofilm infections. In fact, biofilms were resistant to antibiotics at concentrations 10-1000 times greater than the ones required to kill free-living or planktonic cells. The only antibiotics able to inhibit biofilm eradication on 50 % of isolates were ceftaroline and gentamicin. The results suggest that the antibiotic susceptibility patterns

  13. Molecular characterization of α-amylase from Staphylococcus aureus

    PubMed Central

    Lakshmi, Hanumanthu Prasanna; Prasad, Uppu Venkateswara; Yeswanth, Sthanikam; Swarupa, Vimjam; Prasad, Osuru Hari; Narasu, Mangamoori Lakshmi; Sarma, Potukuchi Venkata Gurunadha Krishna

    2013-01-01

    Staphylococcus aureus is one of the prominent Gram positive human pathogen secretes many surface and secretary proteins including various enzymes and pathogenic factors that favour the successful colonization and infection of host tissue. α-amylase is one of the enzymes secreted by S. aureus which catalyses the breakdown of complex sugars to monosaccharides, which are required for colonization and survival of this pathogen in any anatomical locales. In the present study we have cloned, sequenced, expressed and characterized α-amylase gene from S. aureus ATCC12600. The recombinant enzyme has a molecular weight of 58kDa and the kinetics showed Vmax 0.0208±0.033 (mg/ml)/mg/min and Km 10.633±0.737mg/ml. The multiple sequence analysis showed α- amylase of S. aureus exhibited large differences with Bacillus subtilis and Streptococcus bovis. As the crystal structure of S. aureus α- amylase was unavailable, we used homology modelling method to build the structure. The built structure was validated by Ramachandran plot which showed 90% of the residues in the allowed region while no residue was found in the disallowed region and the built structure was close to the crystal structure with Z-Score: -6.85. The structural superimposition studies with α- amylases of Bacillus subtilis and Streptococcus bovis showed distinct differences with RMSD values of 18.158Åand 7.091Å respectively which correlated with enzyme kinetics, indicating α-amylase is different among these bacteria. PMID:23559746

  14. Comparison of the BBL CHROMagar Staph aureus Agar Medium to Conventional Media for Detection of Staphylococcus aureus in Respiratory Samples

    PubMed Central

    Flayhart, Diane; Lema, Clara; Borek, Anita; Carroll, Karen C.

    2004-01-01

    Screening for Staphylococcus aureus has become routine in certain patient populations. This study is the first clinical evaluation of the BBL CHROMagar Staph aureus agar (CSA) medium (BD Diagnostics, Sparks, Md.) for detection of S. aureus in nasal surveillance cultures and in respiratory samples from cystic fibrosis (CF) patients. S. aureus colonies appear mauve on CSA. Other organisms are inhibited or produce a distinctly different colony color. S. aureus was identified from all media by slide coagulase, exogenous DNase, and mannitol fermentation assays. Susceptibility testing was performed using the agar dilution method. A total of 679 samples were evaluated. All samples were inoculated onto CSA. Nasal surveillance cultures were inoculated onto sheep blood agar (SBA) (BD Diagnostics), and samples from CF patients were inoculated onto mannitol salt agar (MSA) (BD Diagnostics). Of the 679 samples cultured, 200 organisms produced a mauve color on CSA (suspicious for S. aureus) and 180 were positive for S. aureus on SBA or MSA. Of 200 CSA-positive samples 191 were identified as S. aureus. Nine mauve colonies were slide coagulase negative and were subsequently identified as Staphylococcus lugdunensis (one), Staphylococcus epidermidis (three), Staphylococcus haemolyticus (one), and Corynebacterium species (four). CSA improved the ability to detect S. aureus by recovering 12 S. aureus isolates missed by conventional media. Of the 192 S. aureus isolates recovered, 122 were methicillin susceptible and 70 were methicillin resistant. Overall, the sensitivity and specificity of CSA in this study were 99.5 and 98%, respectively. There was no difference in the performance of the slide coagulase test or in susceptibility testing performed on S. aureus recovered from CSA compared to SBA or MSA. Our data support the use of CSA in place of standard culture media for detection of S. aureus in heavily contaminated respiratory samples. PMID:15297498

  15. Methicillin-resistant Staphylococcus aureus (mrsa) in a Malaysian hospital.

    PubMed

    Cheong, I; Tan, S C; Wong, Y H; Zainudin, B M; Rahman, M Z

    1994-03-01

    Between August 1990 to November 1991, 905 of 2583 (35.4%) isolates of Staphylococcus aureus were found to be methicillin-resistant in a general hospital in Malaysia. A detailed study of 539 of these isolates showed a high prevalence of methicillin resistant Staphylococcus aureus (MRSA) in the surgical/orthopaedic wards, paediatric wards and the special care unit. The yield of MRSA was highest from wounds/ulcers/skin swabs accounting for 64.2 per cent followed by 6.9 per cent in blood cultures. Vancomycin remains the drug of choice with no resistance detected. The resistance to ciprofloxacin was 6.7 per cent, rifampicin 4.5 per cent and fusidic acid 2.0 per cent. Most isolates were resistant to aminoglycosides. In view of the high prevalence of MRSA in this hospital, the authorities must introduce more effective measures to control its spread as a nosocomial pathogen. Otherwise it may seriously disrupt the efficient delivery of health care services in the country.

  16. Antimicrobial blue light inactivation of Methicillin-resistant Staphylococcus aureus

    NASA Astrophysics Data System (ADS)

    Wang, Yucheng; Dai, Tianhong; Gu, Ying

    2016-10-01

    Background: With the increasing emergence of multidrug-resistant (MDR) bacterial strains, there is a pressing need for the development of alternative treatment for infections. Antimicrobial blue light (aBL) has provided a simple and effective approach. Methods: We first investigated the effectiveness of aBL (415 nm) inactivation of USA300 LAClux (a communityacquired Methicillin-resistant Staphylococcus aureus strain) both in the planktonic and biofilm forms. The survival of the bacteria in suspensions was determined by serial dilution and that of the biofilm-embedded bacteria was determined by bioluminescence quantification. Using a mouse model of thermal burn infected with USA300 LAClux, we further assessed the effectiveness of aBL for treating localized infections. Bioluminescence imaging was performed to monitor in real time bacterial viability in vivo. Results: In vitro study showed that, for the planktonic counterpart of the bacteria or the 24-h-old biofilms, an irradiance of 55 mW/cm2 for 60 min resulted in a 4.61 log10 or 2.56 log10 inactivation, respectively. In vivo study using infected mouse burns demonstrated that a 2.56-log10 inactivation was achieved after 100-mW/cm2 irradiation for 62 min. Conclusions: aBL is a potential alternative approach for treating Methicillin-resistant Staphylococcus aureus infections.

  17. [Staphylococcus aureus variety hominis in a cattle herd].

    PubMed

    Hummel, R; Meene, G

    1979-01-01

    A site-linked hominis variety of Staphylococcus aureus was isolated from a cattle herd. The find coincided with accumulated occurrence of clinical mastitis in cows and the affliction of one milker with a nose furuncle. The origin of the strain was not elucidated. The same strain had been isolated throughout three years of observation from clinical and subclinical mastitis as well as from chronic udder affection of cows, but no extraordinary accumulation of clinically manifest mastitis had been observed. The hominis site variety was quite rare among Staphylococcus aureus strains isolated from other cow herds. Enterotoxin formation was recorded from strains of the hominis site variety and from strains which could not be coordinated with any other of the known site varieties and fell under crystal-violet Type A. No enterotoxin formation was recordable from the strains of the bovis variety. The same applied to the group of staphylococci of crystal-violet Type C which could not be coordinated either with any known site variety and which is assumed to have originated from the hominis site variety. The above findings do not support any conclusion as to whether the cows had been infected by the milker or vice versa.

  18. Back to the Future: Penicillin-Susceptible Staphylococcus aureus.

    PubMed

    Cheng, Matthew P; René, Pierre; Cheng, Alexandre P; Lee, Todd C

    2016-12-01

    Widespread penicillin usage rapidly resulted in the emergence of penicillin resistance in Staphylococcus aureus. However, new data suggest that penicillin susceptibility may be in a period of renaissance. The objective of our study was to quantify penicillin resistance in methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. We retrospectively reviewed all adult MSSA bacteremia from April 2010 to April 2015 at the McGill University Health Centre (Montreal, QC, Canada). Susceptibility to penicillin, erythromycin, clindamycin, and trimethoprim-sulfamethoxazole (TMP-SMX) was determined in accordance with the Clinical & Laboratory Standards Institute guidelines. There were 324 unique episodes of MSSA bacteremia. Ninety (28%) isolates were susceptible to penicillin, 229 (71%) to erythromycin, 239 (74%) to clindamycin, and 317 (98%) to TMP-SMX. Isolates that were penicillin resistant were more likely to also be resistant to other antibiotics, but a statistically significant association was apparent only for erythromycin resistance (76/234, 32.2% vs 19/90, 21.1%, P = .04). The median age of patients was 67.5 years (interquartile range 52-78) and overall in-hospital 30-day mortality was 16.3% (53 deaths). After adjustment for patient age, there was no association between penicillin resistance and either intensive care unit admission or death. More than one-quarter of patients with MSSA bacteremia potentially could be treated with parenteral penicillin, which may offer pharmacokinetic advantages over other beta-lactam drugs and potentially improved outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Staphylococcus aureus recoveries on various brands of membrane filters.

    PubMed

    Alico, R K; Palenchar, C A

    1975-10-01

    Six commercial brands of membrane filters were compared using staphylococcus aureus obtained from pure cultures and from swimming pool water. The following brands of filters were tested: Gelman, Millipore, Nuclepore, Oxoid, Sartorius, and Selectron. Standard membrane filter (MF) procedures and m-Staphylococcus broth were used in the evaluation. Analysis of the results was performed by comparing filter recoveries to the standard plate count using the t-test and the coefficient of variation. The data revealed that recovery on Nuclepore filters was consistently lower than the other brands and showed a wider degree of variation from the mean. All organisms recovered from the pool were gram-positive cocci, and the colonies ranged from white to yellow-gold in color. Approximately 15% of both the white and yellow-gold colonies were coagulase-positive, indicating that colony color alone does not denote the presence of coagulase-positive S. aureus. Since there was no correlation between colony color of the organisms recovered on membrane filters and the presence of coagulase, the feasibility of coagulase testing only the yellow-gold colonies for bathing water analysis is questionable.

  20. Staphylococcus aureus ampicillin-resistant from the odontological clinic environment.

    PubMed

    Bernardo, Wagner Luis de Carvalho; Boriollo, Marcelo Fabiano Gomes; Gonçalves, Reginaldo Bruno; Höfling, José Francisco

    2005-01-01

    The aim of this research was to evaluate the prevalence of Staphylococcus spp. and S. aureus in the odontological clinic environment (air), their production of beta-lactamase and antibacterial susceptibility to the major antibiotics utilized in medical particle. During 12 months of samples collect were isolated 9775 CFU by MSA medium suggesting a high amount of Staphylococcus spp. in the clinic environment which can appear through aerosols. A total of 3149 colonies (32.2%) were suggestive of pathogenic staphylococci. Gram coloration, catalase test, colony-mallow growing on chromogenic medium, and coagulase test confirmed the identity of 44 (0.45%) S. aureus isolates. Of these, 35 isolates (79.5%) showed production of beta-lactamase by Cefinase discs and resistance to ampicillin, erythromycin (7 isolates) and tetracycline (1 isolate) suggesting the existence of multiresistant isolates. The evaluation of the oxacillin MIC by Etest assays showed susceptibility patterns suggesting the inexistence of the mecA gene in chromosomal DNA. These results point out to the need of a larger knowledge on the contamination means and propagation of this microorganism into the odontological clinic.

  1. [Methicillin resistant Staphylococcus aureus community acquired meningitis: a case report].

    PubMed

    Spini, Roxana Gabriela; Ferraris, Verónica; Glasman, María Patricia; Orofino, Guillermina; Casanovas, Alejandra; Debaisi, Gustavo

    2014-12-01

    Community-acquired Staphylococcus aureus (CA-SA) infections are becoming more frequent. Most cases present an infection of skin and soft tissue, and the most invasive forms observed are osteoarticular and pleuropulmonary infections. Meningitis is a rare manifestation of Staphylococcus aureus infections. We describe an unusual case of CA-MRSA infection. An infant of eight months presented with signs of irritability and 4 days duration fever, with alternating sensory and abdomen pain. Acute abdomen surgery was discarded and hospitalization was decided with diagnosis of sepsis due to probable enteral focus; antibiotics were indicated. Blood cultures and cerebrospinal fluid culture were positive for MRSA. Sepsis with meningitis by MRSA was diagnosed. On the 7th day of hospitalization the infant presented neurological signs and symptoms. On the resolution computed tomography and the magnetic resonance, images compatible with myelitis were observed. The patient complied with the 21 day endovenous treatment, and showed positive results, being discharged from hospital a month after the appearance of the symptoms.

  2. Staphylococcus aureus Entrance into the Dairy Chain: Tracking S. aureus from Dairy Cow to Cheese

    PubMed Central

    Kümmel, Judith; Stessl, Beatrix; Gonano, Monika; Walcher, Georg; Bereuter, Othmar; Fricker, Martina; Grunert, Tom; Wagner, Martin; Ehling-Schulz, Monika

    2016-01-01

    Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. one thousand hundred seventy six one thousand hundred seventy six quarter milk (QM) samples of all cows in lactation (n = 294) and representative samples form bulk tank milk (BTM) of all farms were surveyed for coagulase positive (CPS) and coagulase negative Staphylococci (CNS). Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing), dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day 14 of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej) of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus, our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires

  3. Staphylococcus aureus Entrance into the Dairy Chain: Tracking S. aureus from Dairy Cow to Cheese.

    PubMed

    Kümmel, Judith; Stessl, Beatrix; Gonano, Monika; Walcher, Georg; Bereuter, Othmar; Fricker, Martina; Grunert, Tom; Wagner, Martin; Ehling-Schulz, Monika

    2016-01-01

    Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. one thousand hundred seventy six one thousand hundred seventy six quarter milk (QM) samples of all cows in lactation (n = 294) and representative samples form bulk tank milk (BTM) of all farms were surveyed for coagulase positive (CPS) and coagulase negative Staphylococci (CNS). Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing), dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day 14 of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej) of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus, our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires

  4. Staphylococcus aureus Clumping Factor A Remains a Viable Vaccine Target for Prevention of S. aureus Infection.

    PubMed

    Anderson, Annaliesa S; Scully, Ingrid L; Buurman, Ed T; Eiden, Joseph; Jansen, Kathrin U

    2016-03-08

    In a recent article, X. Li et al. [mBio 7(1):e02232-15, 2016, http://dx.doi.org/10.1128/mBio.02232-15] investigate the utility of a vaccine composed of the Staphylococcus aureus protein clumping factor A (ClfA) in protecting mice from S. aureus infection. ClfA, one of the first proteins to be identified as a potential vaccine antigen for S. aureus prophylaxis, is currently a component of several investigational vaccines. The authors conclude that ClfA may not be effective for S. aureus prophylaxis. In contrast, previously published papers reporting positive data suggested that ClfA was potentially an important vaccine target to prevent invasive S. aureus disease. This commentary addresses the observed differences between the findings of Li et al. and those from other publications, highlighting the importance for preclinical vaccine antigen assessments to reflect the biological role of said antigen in virulence and, consequently, the importance of choosing appropriate preclinical disease models to test such antigens.

  5. Staphylococcus aureus Clumping Factor A Remains a Viable Vaccine Target for Prevention of S. aureus Infection

    PubMed Central

    Scully, Ingrid L.; Buurman, Ed T.; Eiden, Joseph; Jansen, Kathrin U.

    2016-01-01

    ABSTRACT In a recent article, X. Li et al. [mBio 7(1):e02232-15, 2016, http://dx.doi.org/10.1128/mBio.02232-15] investigate the utility of a vaccine composed of the Staphylococcus aureus protein clumping factor A (ClfA) in protecting mice from S. aureus infection. ClfA, one of the first proteins to be identified as a potential vaccine antigen for S. aureus prophylaxis, is currently a component of several investigational vaccines. The authors conclude that ClfA may not be effective for S. aureus prophylaxis. In contrast, previously published papers reporting positive data suggested that ClfA was potentially an important vaccine target to prevent invasive S. aureus disease. This commentary addresses the observed differences between the findings of Li et al. and those from other publications, highlighting the importance for preclinical vaccine antigen assessments to reflect the biological role of said antigen in virulence and, consequently, the importance of choosing appropriate preclinical disease models to test such antigens. PMID:26956591

  6. Investigation of biofilm formation in clinical isolates of Staphylococcus aureus.

    PubMed

    Cassat, James E; Lee, Chia Y; Smeltzer, Mark S

    2007-01-01

    As with many other bacterial species, the most commonly used method to assess staphylococcal biofilm formation in vitro is the microtiter plate assay. This assay is particularly useful for comparison of multiple strains including large-scale screens of mutant libraries. When such screens are applied to the coagulase-negative staphylococci in general, and Staphylococcus epidermidis in particular, they are relatively straightforward by comparison with microtiter plate assays used to assess biofilm formation in other bacterial species. However, in the case of clinical isolates of Staphylococcus aureus, including methicillin-resistant S. aureus, we have found it necessary to employ specific modifications including precoating of the wells of the microtiter plate with plasma proteins and supplementation of the medium with both salt and glucose. In this chapter, we describe the microtiter plate assay in the specific context of clinical isolates of S. aureus and the use of these modifications. A second in vitro method, which also is generally dependent on coating with plasma proteins and supplementation of the growth medium, is the use of flow cells. In this method, bacteria are allowed to attach to a surface and then monitored with respect to their ability to remain attached to the substrate and differentiate into mature biofilms under the constant pressure of fluid shear force. Although flow cells are not applicable to large-scale screens, we have found that they provide a more reproducible and accurate assessment of the capacity of S. aureus clinical isolates to form a biofilm. They also provide a means of analyzing structural differences in biofilm architecture and isolating bacteria and/or spent media for analysis of physiological and metabolic changes associated with the adaptive response to growth in a biofilm. While a primary focus of this chapter is on the use of in vitro assays to assess biofilm formation in clinical isolates of S. aureus, it is important to

  7. Detection of enterotoxigenic Staphylococcus aureus isolates in domestic dairy products

    PubMed Central

    Imani Fooladi, AA; Tavakoli, HR; Naderi, A

    2010-01-01

    Background and objectives Staphylococcus aureusis a one of THE most frequent causes of food poisoning (FP) in dairy products. The main etiologic agents of FP are staphylococcal enterotoxins (SE). There are different types of SE; types A (SEA) and B (SEB) are the most clinically important enterotoxins. Traditional dairy products are still produced in small batches and sold by some vendors without a permit from the Ministry of Health. This study focuses on the molecular and serological detection of enterotoxigenic Staphylococcus aureus SEA and SEB genes and its products, respectively from samples of such traditional products. Materials and Methods 100 samples from dairy products were produced under sterile conditions via traditional methods and were transported to the laboratory. The samples were cultured and identified by routine bacteriological methods. The isolated bacteria were evaluated by PCR tests for detection of the genes encoding SEA and SEB. Subsequently, the ability of these strains to produce enterotoxin was examined by Sac's culture method and was confirmed by Sigel Radial Immounodiffussion (SRID). Results The results indicated that 32% of the dairy products were contaminated by S. aureus (cream 18%, cheese 10%, milk 4%). The PCR results showed that 15.6% of the S. aureus isolates possessed the SEA gene, 9.3% had the SEB gene, and 6.2% possessed both genes. The evaluation of enterotoxin production indicated that 80% of SEA and 33% of SEB genes were expressed. Conclusion Enterotoxins SEA and SEB are heat stable and consequently; heating has no effect on dairy products contaminated by entertoxins. Subsequently, gastritis may occur within several hours after consumption. Our findings suggest that PCR is a rapid, sensitive, specific, and inexpensive method for detecting SE and can replace the traditional assays. PMID:22347562

  8. Staphylococcus aureus leucocidin, a virulence factor in bovine mastitis.

    PubMed

    Younis, Ahmed; Krifucks, Oleg; Fleminger, Gideon; Heller, Elimelech D; Gollop, Natan; Saran, Arthur; Leitner, Gabriel

    2005-05-01

    The involvement of Staphylococcus aureus exosecretions in bovine udder infection (Younis et al. 2003) suggests that four different monomer protein bands appearing between 36 and 31 kDa, are associated with the severity of the cow's infection response. Three out of these four bands have been identified by means of protein sequencing. Band B, with a MW of 35 kDa was identified as Panton-Valentaine leucocidin LukF'-PV chain- Staph. aureus; band C, with a MW of 32 kDa was identified as leucocidin chain LukM precursor- Staph. aureus; and band D was found to be similar, but not identical, to phosphatidylinositol-specific phospholipase-C-X. Bands B and C were purified by gel filtration using FPLC. The ability of these proteins to induce udder inflammation in vivo, and proliferation response in vitro and cytokine secretion were tested for both the crude exosecretions and purified bands. Three cows were inoculated intracisternally, with three quarters receiving either 0.007-0.008 mg (as total proteins) of Staph. aureus FR2449/1 bacterial exosecretion, pooled fraction 39-41 (bands B and C), or culture broth medium. The fourth quarter was left free as a control. Quarters that received fraction 39-41 of Staph. aureus FR2449/1, exhibited induced inflammation, which was indicated by increased somatic cell count and enhanced NAGase activity that was significantly higher than that of the original Staph. aureus FR2449/1 bacterial exosecretion. Proliferation tests of bovine blood lymphocytes in vitro showed that the pooled fraction 39-41 stimulated bovine proliferation of mononuclear cells much more than the original Staph. aureus FR2449/1 bacterial exosecretion. Secretion of TNF-alpha, IL-1beta, IL-6 and IL-8 was in accordance with the contents of LukF'-PV and LukM precursor in the exosecretions. The results suggest that LukM/ LukF' induce inflammation into the udder by a mechanism similar to that of LPS or by a unique mechanism(s) which requires further investigation.

  9. Epidemiology of Staphylococcus aureus in Italy: First nationwide survey, 2012.

    PubMed

    Campanile, Floriana; Bongiorno, Dafne; Perez, Marianna; Mongelli, Gino; Sessa, Laura; Benvenuto, Sabrina; Gona, Floriana; Varaldo, Pietro E; Stefani, Stefania

    2015-12-01

    A 3-month epidemiological study to determine the prevalence and antibiotic resistance of Staphylococcus aureus nosocomial infections was performed in 52 centres throughout Italy in 2012. A total of 21,873 pathogens were analysed. The prevalence of S. aureus among all nosocomial pathogens isolated in that period was 11.6% (n=2541), whilst the prevalence of methicillin-resistant S. aureus (MRSA) among the S. aureus was 35.8% (n=910). All tested antimicrobials demonstrated ≥92.2% susceptibility against methicillin-susceptible S. aureus, with the exception of clindamycin (89.7%) and erythromycin (84.2%). Among MRSA, percentages of resistance ranged from 12.6% to >39% for tetracycline, rifampicin, clindamycin and gentamicin; higher percentages were found for erythromycin (65.4%) and fluoroquinolones (72.3-85.8%). Overall, the glycopeptide minimum inhibitory concentration (MIC) distribution showed that 58.3% of strains possessed MICs of 1-2mg/L and few strains were linezolid- or daptomycin-resistant. Molecular characterisation was performed on 102 MRSA selected from Northern, Central and Southern regions. Five major clones were found: Italian/ST228-I (t001-t023-t041-t1686-t3217), 33.3%; USA500/ST8-IV (t008), 17.6%; E-MRSA15/ST22-IVh (t020-t025-t032-t223), 16.7%; USA100/ST5-II (t002-t653-t1349-t2164-t3217-t388), 14.7%; and Brazilian/ST239/241-III (t030-t037), 3.9%. Five PVL-positive CA-MRSA isolates, belonging to USA300 and minor clones, were also identified. In conclusion, this first nationwide surveillance study showed that in Italy, S. aureus infections accounted for 11.6% of all nosocomial infections; MRSA accounted for approximately one-third of the S. aureus isolates and these were multidrug-resistant organisms. Five major MRSA epidemic clones were observed and were inter-regionally distributed, with ST228-SCCmecI becoming predominant.

  10. Genome Sequences of Four Staphylococcus aureus Strains Isolated from Bovine Mastitis.

    PubMed

    Kant, Ravi; Taponen, Suvi; Koort, Joanna; Paulin, Lars; Åvall-Jääskeläinen, Silja; Palva, Airi

    2015-04-23

    Staphylococcus aureus is a major causative agent of mastitis in dairy cows. The pathogenicity of S. aureus may vary; it is able to cause severe clinical mastitis, but most often it is associated with chronic subclinical mastitis. Here, we present the genome assemblies of four S. aureus strains from bovine mastitis. Copyright © 2015 Kant et al.

  11. Genome Sequences of Four Staphylococcus aureus Strains Isolated from Bovine Mastitis

    PubMed Central

    Taponen, Suvi; Koort, Joanna; Paulin, Lars; Åvall-Jääskeläinen, Silja

    2015-01-01

    Staphylococcus aureus is a major causative agent of mastitis in dairy cows. The pathogenicity of S. aureus may vary; it is able to cause severe clinical mastitis, but most often it is associated with chronic subclinical mastitis. Here, we present the genome assemblies of four S. aureus strains from bovine mastitis. PMID:25908141

  12. Draft Genome Sequences of 14 Staphylococcus aureus Sequence Type 5 Isolates from California, USA

    PubMed Central

    Hau, Samantha J.; Bayles, Darrell O.; Alt, David P.

    2017-01-01

    ABSTRACT Staphylococcus aureus is part of the human epithelial microbiota; however, it is also a pathogen. The acquisition of mobile genetic elements plays a role in the virulence of S. aureus isolates and contributes to treatment failures. This report details the draft genome sequences of 14 clinical S. aureus isolates. PMID:28360166

  13. Complete Genome Sequences of Two Staphylococcus aureus Sequence Type 5 Isolates from California, USA

    PubMed Central

    Hau, Samantha J.; Bayles, Darrell O.; Alt, David P.

    2017-01-01

    ABSTRACT Staphylococcus aureus causes a variety of human diseases ranging in severity. The pathogenicity of S. aureus can be partially attributed to the acquisition of mobile genetic elements. In this report, we provide two complete genome sequences from human clinical S. aureus isolates. PMID:28360167

  14. Phenotypic and genotypic antimicrobial resistance traits of foodborne Staphylococcus aureus isolates from Shanghai

    USDA-ARS?s Scientific Manuscript database

    Staphylococcus aureus is a recognized pathogen in humans, which causes nosocomial infections and food poisoning. The transmission of antibiotic resistant S. aureus (ARSA), especially methicillin-resistant S. aureus (MRSA), between food products and humans has become a serious problem. Hence, it is n...

  15. Oxacillin-resistant and multidrug-resistant Staphylococcus aureus in Lima, Peru.

    PubMed

    Seas, C; Hernandez, K; Ramos, R; Bazan, E; Rodriguez, I; Torres, A; Zamudio, C; Gotuzzo, E

    2006-02-01

    In a hospital in Lima, Peru, a review of 103 Staphylococcus aureus infections was conducted during 2002. The prevalence of oxacillin-resistant S. aureus strains was 68%; 25% of strains were resistant to multiple drugs. Previous use of antibiotics and undergoing a surgical procedure during the current hospital stay were associated with the presence of an oxacillin-resistant S. aureus strain.

  16. The intracellular effects of manuka honey on Staphylococcus aureus.

    PubMed

    Henriques, A F; Jenkins, R E; Burton, N F; Cooper, R A

    2010-01-01

    The purpose of this study was to investigate the effect of manuka honey on Staphylococcus aureus in order to identify the intracellular target site. The mode of inhibition of manuka honey against S. aureus NCTC 10017 was investigated by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and the effect of time on viability. Structural changes were observed by scanning (SEM) and transmission electron microscopy (TEM) of cells suspended for 4 h at 37 degrees C in 0.05 mM Tris buffer containing 10% (w/v) manuka honey and were compared to cells in buffer alone or buffer containing 10% (w/v) artificial honey (to assess osmotic damage). A bactericidal mode of inhibition for manuka honey on S. aureus was established. Marked structural changes in honey-treated cells were seen only with TEM, where a statistically significant increase in the number of whole cells with completed septa compared to untreated cells were observed (P < 0.05). Structural changes found with TEM suggest that honey-treated cells had failed to progress normally through the cell cycle and accumulated with fully formed septa at the point of cell division without separating. Sugars were not implicated in this effect. The staphylococcal target site of manuka honey involves the cell division machinery.

  17. Modulation of Drug Resistance in Staphylococcus aureus with Coumarin Derivatives

    PubMed Central

    de Araújo, Rodrigo Santos Aquino; Barbosa-Filho, José Maria; Scotti, Marcus Tullius; Scotti, Luciana; da Cruz, Ryldene Marques Duarte; Falcão-Silva, Vivyanne dos Santos; de Siqueira-Júnior, José Pinto; Mendonça-Junior, Francisco Jaime Bezerra

    2016-01-01

    Semisynthetic and commercial coumarins were investigated for their antibacterial and adjuvant properties with antibiotic agents against norfloxacin, erythromycin, and tetracycline resistant Staphylococcus aureus as based on efflux mechanisms. The coumarins and certain commercial antibiotics had their Minimum Inhibitory Concentrations determined by broth microdilution assay against resistant S. aureus strains which overexpress efflux pump proteins. For evaluation of the modulatory activity, the antibiotics MICs were determined in the presence of the coumarin derivatives at subinhibitory concentration. Although the coumarins did not display relevant antibacterial activity (MIC ≥ 128 µg/mL), they did modulate the antibiotics activities. Various coumarins, especially the alkylated derivatives in combination with antibiotics at subinhibitory concentrations, modulated antibiotic activity, reducing the MIC for tetracycline and norfloxacin by 2 to 8 times. Polar Surface Area (PSA) studies were performed and the fact that the presence of apolar groups is an important factor for the modulatory activity of coumarins was corroborated. Docking on the Penicillin-Binding Protein from MRSA identified that 18 is a potential ligand presenting low Ebinding. The results indicate that coumarin derivatives modulated antibiotic resistance and may be used as potential antibiotic adjuvants, acting by bacterial efflux pump inhibition in S. aureus. PMID:27200211

  18. Investigational drugs to treat methicillin-resistant Staphylococcus aureus

    PubMed Central

    Vuong, Cuong; Yeh, Anthony J; Cheung, Gordon YC; Otto, Michael

    2016-01-01

    Introduction Staphylococcus aureus remains one of the leading causes of morbidity and mortality worldwide. This is to a large extent due to antibiotic-resistant strains, in particular methicillin-resistant S. aureus (MRSA). While the toll of invasive MRSA infections appears to decrease in U.S. hospitals, the rate of community-associated MRSA infections remains constant and there is a surge of MRSA in many other countries. This situation calls for continuing if not increased efforts to find novel strategies to combat MRSA infections. Areas covered This review will provide an overview of current investigational antibiotics in clinical development (up to phase II), and of therapeutic antibodies and alternative drugs against S. aureus in preclinical and clinical development, including a short description of the mechanism of action and a presentation of microbiological and clinical data. Expert opinion Increased recent antibiotic development efforts and results from pathogenesis research have led to several new antibiotics and alternative drugs, as well as a more informed selection of targets for vaccination efforts against MRSA. This developing portfolio of novel anti-staphylococcal drugs will hopefully provide us with additional and more efficient ways to combat MRSA infections in the near future and prevent us from running out of treatment options, even if new resistances arise. PMID:26536498

  19. Persister formation in Staphylococcus aureus is associated with ATP depletion

    SciTech Connect

    Conlon, Brian P.; Rowe, Sarah E.; Gandt, Autumn Brown; Nuxoll, Austin S.; Donegan, Niles P.; Zalis, Eliza A.; Clair, Geremy; Adkins, Joshua N.; Cheung, Ambrose L.; Lewis, Kim

    2016-04-18

    Persisters are dormant phenotypic variants of bacterial cells that are tolerant to killing by antibiotics1. Persisters are associated with chronic bacterial infection and antibiotic treatment failure. In Escherichia coli, toxin/antitoxin (TA) modules are responsible for persister formation. The mechanism of persister formation in Gram positive bacteria is unknown. Staphylococcus aureus is a major human pathogen, responsible for a variety of chronic and relapsing infections such as osteomyelitis, endocarditis and infections of implanted devices. Deleting TA modules in S. aureus did not affect the level of persisters. Here we show that S. aureus persisters are produced due to a stochastic entrance to stationary phase accompanied by a drop in intracellular ATP. Cells expressing stationary state markers are present throughout the growth phase, increasing in frequency with cell density. Cell sorting revealed that expression of stationary markers was associated with a 100-1000 fold increased likelihood of survival to antibiotic challenge. We find that the antibiotic tolerance of these cells is due to a drop in intracellular ATP. The ATP level of the cell is predictive of bactericidal antibiotic efficacy and explains bacterial tolerance to antibiotic treatment.

  20. Inhibition of Staphylococcus aureus Adherence to Collagen under Dynamic Conditions

    PubMed Central

    Mohamed, Nehal; Teeters, Mark A.; Patti, Joseph M.; Höök, Magnus; Ross, Julia M.

    1999-01-01

    Staphylococcus aureus is the most common etiological agent of bacterial arthritis and acute osteomyelitis and has been shown to bind to type II collagen under static and dynamic conditions. We have previously reported the effect of shear on the adhesion of S. aureus Phillips to collagen and found that this process is shear dependent (Z. Li, M. Höök, J. M. Patti, and J. M. Ross, Ann. Biomed. Eng. 24[Suppl. 1]:S–55). In this study, we used recombinant collagen adhesin fragments as well as polyclonal antibodies generated against adhesin fragments in attempts to inhibit bacterial adhesion. A parallel-plate flow chamber was used in a dynamic adhesion assay, and quantification of adhesion was accomplished by phase contrast video microscopy coupled with digital image processing. We report that both recombinant fragments studied, M19 and M55, and both polyclonal antibodies studied, α-M17 and α-M55, inhibit adhesion to varying degrees and that these processes are shear dependent. The M55 peptide and α-M55 cause much higher levels of inhibition than M19 and α-M17, respectively, at all wall shear rates studied. Our results demonstrate the importance of using a dynamic system in the assessment of inhibitory strategies and suggest the possible use of M55 and α-M55 in clinical applications to prevent infections caused by S. aureus adhesion to collagen. PMID:9916063

  1. Bap, a Staphylococcus aureus Surface Protein Involved in Biofilm Formation

    PubMed Central

    Cucarella, Carme; Solano, Cristina; Valle, Jaione; Amorena, Beatriz; Lasa, Íñigo; Penadés, José R.

    2001-01-01

    Identification of new genes involved in biofilm formation is needed to understand the molecular basis of strain variation and the pathogenic mechanisms implicated in chronic staphylococcal infections. A biofilm-producing Staphylococcus aureus isolate was used to generate biofilm-negative transposon (Tn917) insertion mutants. Two mutants were found with a significant decrease in attachment to inert surfaces (early adherence), intercellular adhesion, and biofilm formation. The transposon was inserted at the same locus in both mutants. This locus (bap [for biofilm associated protein]) encodes a novel cell wall associated protein of 2,276 amino acids (Bap), which shows global organizational similarities to surface proteins of gram-negative (Pseudomonas aeruginosa and Salmonella enterica serovar Typhi) and gram-positive (Enteroccocus faecalis) microorganisms. Bap's core region represents 52% of the protein and consists of 13 successive nearly identical repeats, each containing 86 amino acids. bap was present in a small fraction of bovine mastitis isolates (5% of the 350 S. aureus isolates tested), but it was absent from the 75 clinical human S. aureus isolates analyzed. All staphylococcal isolates harboring bap were highly adherent and strong biofilm producers. In a mouse infection model bap was involved in pathogenesis, causing a persistent infection. PMID:11292810

  2. Investigational drugs to treat methicillin-resistant Staphylococcus aureus.

    PubMed

    Vuong, Cuong; Yeh, Anthony J; Cheung, Gordon Y C; Otto, Michael

    2016-01-01

    Staphylococcus aureus remains one of the leading causes of morbidity and mortality worldwide. This is to a large extent due to antibiotic-resistant strains, in particular methicillin-resistant S. aureus (MRSA). While the toll of invasive MRSA infections appears to decrease in U.S. hospitals, the rate of community-associated MRSA infections remains constant and there is a surge of MRSA in many other countries, a situation that calls for continuing if not increased efforts to find novel strategies to combat MRSA infections. This review provides an overview of current investigational drugs and therapeutic antibodies against S. aureus in early clinical development (up to phase II clinical development). It includes a short description of the mechanism of action and a presentation of microbiological and clinical data. Increased recent antibiotic development efforts and results from pathogenesis research have led to several new antibiotics and therapies, such as anti-virulence drugs, as well as a more informed selection of targets for vaccination efforts against MRSA. This developing portfolio of novel anti-staphylococcal drugs will hopefully provide us with additional and more efficient ways to combat MRSA infections in the near future and prevent us from running out of treatment options, even if new resistances arise.

  3. Beta-hemolysin promotes skin colonization by Staphylococcus aureus.

    PubMed

    Katayama, Yuki; Baba, Tadashi; Sekine, Miwa; Fukuda, Minoru; Hiramatsu, Keiichi

    2013-03-01

    Colonization by Staphylococcus aureus is a characteristic feature of several inflammatory skin diseases and is often followed by epidermal damage and invasive infection. In this study, we investigated the mechanism of skin colonization by a virulent community-acquired methicillin-resistant S. aureus (CA-MRSA) strain, MW2, using a murine ear colonization model. MW2 does not produce a hemolytic toxin, beta-hemolysin (Hlb), due to integration of a prophage, Sa3mw, inside the toxin gene (hlb). However, we found that strain MW2 bacteria that had successfully colonized murine ears included derivatives that produced Hlb. Genome sequencing of the Hlb-producing colonies revealed that precise excision of prophage Sa3mw occurred, leading to reconstruction of the intact hlb gene in their chromosomes. To address the question of whether Hlb is involved in skin colonization, we constructed MW2-derivative strains with and without the Hlb gene and then subjected them to colonization tests. The colonization efficiency of the Hlb-producing mutant on murine ears was more than 50-fold greater than that of the mutant without hlb. Furthermore, we also showed that Hlb toxin had elevated cytotoxicity for human primary keratinocytes. Our results indicate that S. aureus Hlb plays an important role in skin colonization by damaging keratinocytes, in addition to its well-known hemolytic activity for erythrocytes.

  4. Enterotoxigenic properties of Staphylococcus aureus isolated from goats' milk cheese.

    PubMed

    Akineden, Omer; Hassan, Abdulwahed Ahmed; Schneider, Elisabeth; Usleber, Ewald

    2008-05-31

    Goats' milk cheeses (n=181) from the Hessian market (retail shops, weekly markets, farm markets) were quantitatively analysed for Staphylococcus (S.) aureus, and 14 were found positive. From these samples, 64 isolates of S. aureus were characterized biochemically and genetically, including their potential to produce staphylococcal enterotoxins (SE). SE genes sea to selo was studied by PCR and gene expression was evaluated by reverse transcriptase (RT)-PCR. SEA-SEE production in culture was determined by enzyme immunoassay (EIA). One isolate produced SEA, 18 isolates (from 4 samples) produced SEC, while SEB, SED, and SEE were not found. Toxin production was in agreement with PCR and RT-PCR results for the presence and expression, respectively, of the corresponding toxin genes. Trans-SE genes seg, sei, selm, seln, and selo were detected in 14 isolates from 4 cheese samples, exclusively as clusters. These samples were all from small-scale producers which directly or indirectly market their products regionally. No isolate was positive for seh or sej. RT-PCR detected the presence of the corresponding mRNA for all genes except selo, further indicating the possibility that respective proteins indeed have been produced in culture. These results suggest that S. aureus in goats' milk cheese potentially produces SE like proteins, besides SEA and SEC.

  5. Are B Lymphocytes of Importance in Severe Staphylococcus aureus Infections?

    PubMed Central

    Gjertsson, Inger; Hultgren, Olof Hörnquist; Stenson, Martin; Holmdahl, Rikard; Tarkowski, Andrzej

    2000-01-01

    To investigate the role of B cells in experimental, superantigen-mediated Staphylococcus aureus arthritis and sepsis, we used gene-targeted B-cell-deficient mice. The mice were inoculated intravenously with a toxic shock syndrome toxin 1 (TSST-1)-producing S. aureus strain. The B-cell-deficient and thus agamma-globulinemic mice showed striking similarities to the wild-type control animals with respect to the development of arthritis, the mortality rate, and the rate of bacterial clearance. Surprisingly, we found that the levels of gamma interferon in serum were significantly lower (P < 0.0001) in B-cell-deficient mice than in the controls, possibly due to impaired superantigen presentation and a diminished expression of costimulatory molecules. In contrast, the levels of interleukin-4 (IL-4), IL-6, and IL-10 in serum were equal in both groups. Our findings demonstrate that neither mature B cells nor their products significantly contribute to the course of S. aureus-induced septic arthritis. PMID:10768927

  6. Evaluation of vancomycin MIC creep in Staphylococcus aureus.

    PubMed

    Diaz, Raquel; Ramalheira, Elmano; Afreixo, Vera; Gago, Bruno

    2017-09-01

    Vancomycin is the primary treatment for methicillin-resistant Staphylococcus aureus (MRSA). However, an increasing proportion of MRSA isolates with high minimum inhibitory concentrations (MICs) within the susceptible range (vancomycin 'MIC creep') is being observed. The aim of this study was to assess the vancomycin MIC distribution for S. aureus isolates over a period of 4 years in Centro Hospitalar Baixo Vouga (Aveiro, Portugal) and to identify differences in vancomycin MIC determined by different susceptibility testing methods. For each S. aureus isolate, the vancomycin MIC was assayed by the VITEK(®)2 automated system and the broth microdilution testing method. The results showed significant differences in vancomycin MIC by different methods (P=0.021, sign test) and did not suggest the presence of vancomycin MIC creep during the study period. Vancomycin MIC creep is a regional problem, therefore it can only be assessed through the evaluation of local susceptibility profiles, and antibiogram based on real MIC assay should be an essential element in local MRSA infection clinical management. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  7. Clinical relevance of FASII bypass in Staphylococcus aureus.

    PubMed

    Gloux, Karine; Guillemet, Mélanie; Soler, Charles; Morvan, Claire; Halpern, David; Pourcel, Christine; Vu Thien, Hoang; Lamberet, Gilles; Gruss, Alexandra

    2017-02-13

    The need for new antimicrobials to treat bacterial infections has led to the use of fatty acid synthesis (FASII) enzymes as front-line targets. However, recent studies suggest that FASII inhibitors may not work against the opportunist pathogen Staphylococcus aureus, as environmental fatty acids favor emergence of multi-anti-FASII resistance. As fatty acids are abundant in the host, and one FASII inhibitor, triclosan, is widespread, we investigated whether fatty acid pools impact resistance in clinical and veterinary S. aureus isolates. Simple addition of fatty acids to screening medium led to a 50% increase in triclosan resistance, as tested in 700 isolates. Moreover, non-culturable triclosan-resistant fatty acid auxotrophs, which escape detection under routine conditions, were uncovered in primary patient samples. FASII bypass in selected isolates correlated with polymorphisms in acc and fabD loci. We conclude that fatty-acid-dependent strategies to escape FASII inhibition are common among S. aureus isolates and correlate with anti-FASII resistance and emergence of non-culturable variants.

  8. Inhibitory effects of antibiofilm compound 1 against Staphylococcus aureus biofilms.

    PubMed

    Shrestha, Looniva; Kayama, Shizuo; Sasaki, Michiko; Kato, Fuminori; Hisatsune, Junzo; Tsuruda, Keiko; Koizumi, Kazuhisa; Tatsukawa, Nobuyuki; Yu, Liansheng; Takeda, Kei; Sugai, Motoyuki

    2016-03-01

    A novel benzimidazole molecule that was identified in a small-molecule screen and is known as antibiofilm compound 1 (ABC-1) has been found to prevent bacterial biofilm formation by multiple bacterial pathogens, including Staphylococcus aureus, without affecting bacterial growth. Here, the biofilm inhibiting ability of 156 μM ABC-1 was tested in various biofilm-forming strains of S. aureus. It was demonstrated that ABC-1 inhibits biofilm formation by these strains at micromolar concentrations regardless of the strains' dependence on Polysaccharide Intercellular Adhesin (PIA), cell wall-associated protein dependent or cell wall- associated extracellular DNA (eDNA). Of note, ABC-1 treatment primarily inhibited Protein A (SpA) expression in all strains tested. spa gene disruption showed decreased biofilm formation; however, the mutants still produced more biofilm than ABC-1 treated strains, implying that ABC-1 affects not only SpA but also other factors. Indeed, ABC-1 also attenuated the accumulation of PIA and eDNA on cell surface. Our results suggest that ABC-1 has pleotropic effects on several biofilm components and thus inhibits biofilm formation by S. aureus.

  9. Improved lux reporters for use in Staphylococcus aureus.

    PubMed

    Mesak, Lili Rosana; Yim, Grace; Davies, Julian

    2009-05-01

    The use of luxABCDE (lux) offers certain advantages over other reporters, such as: lacZ and xylE. It is real time and its signal generation is produced without the requirement for any additional substrates. In some bacteria such as Staphylococcus spp, light production by luciferase is restricted because of a limited availability of endogenous substrates such as fatty acid aldehyde. We describe the construction of promoterless-lux cloning vectors, pGYlux and pAmilux. S. aureus carrying B. subtilis xyl/tetO promoter fused to the lux genes of pGYlux gave up to a 2.5-fold enhancement of luminescence over S. aureus carrying the xyl/tetO promoter fused to lux genes of the previously published parent vector pAL2. Furthermore, pAmilux showed a 6-fold enhancement of lux expression when compared to pGYlux in S. aureus. This was achieved by cloning the constitutive ami promoter upstream of the luxCDE genes to increase endogenous fatty acid aldehyde production while maintaining its reporter functionality by fusing promoters to the luxAB genes.

  10. Planktonic Aggregates of Staphylococcus aureus Protect against Common Antibiotics

    PubMed Central

    Haaber, Jakob; Cohn, Marianne Thorup; Frees, Dorte; Andersen, Thorbjørn Joest; Ingmer, Hanne

    2012-01-01

    Bacterial cells are mostly studied during planktonic growth although in their natural habitats they are often found in communities such as biofilms with dramatically different physiological properties. We have examined another type of community namely cellular aggregates observed in strains of the human pathogen Staphylococcus aureus. By laser-diffraction particle–size analysis (LDA) we show, for strains forming visible aggregates, that the aggregation starts already in the early exponential growth phase and proceeds until post-exponential phase where more than 90% of the population is part of the aggregate community. Similar to some types of biofilm, the structural component of S. aureus aggregates is the polysaccharide intercellular adhesin (PIA). Importantly, PIA production correlates with the level of aggregation whether altered through mutations or exposure to sub-inhibitory concentrations of selected antibiotics. While some properties of aggregates resemble those of biofilms including increased mutation frequency and survival during antibiotic treatment, aggregated cells displayed higher metabolic activity than planktonic cells or cells in biofilm. Thus, our data indicate that the properties of cells in aggregates differ in some aspects from those in biofilms. It is generally accepted that the biofilm life style protects pathogens against antibiotics and the hostile environment of the host. We speculate that in aggregate communities S. aureus increases its tolerance to hazardous environments and that the combination of a biofilm-like environment with mobility has substantial practical and clinical importance. PMID:22815921

  11. Staphylococcus aureus Regulatory RNAs as Potential Biomarkers for Bloodstream Infections

    PubMed Central

    Bordeau, Valérie; Cady, Anne; Revest, Matthieu; Rostan, Octavie; Sassi, Mohamed; Tattevin, Pierre; Donnio, Pierre-Yves

    2016-01-01

    Staphylococcus aureus is a commensal bacterium and pathogen. Identifying biomarkers for the transition from colonization to disease caused by this organism would be useful. Several S. aureus small RNAs (sRNAs) regulate virulence. We investigated presence and expression of 8 sRNAs in 83 S. aureus strains from 42 patients with sepsis or septic shock and 41 asymptomatic colonized carriers. Small pathogenicity island sRNAs sprB and sprC were clade specific. Six sRNAs had variable expression not correlated with clinical status. Expression of RNAIII was lower in strains from septic shock patients than in strains from colonized patients. When RNAIII was associated with expression of sprD, colonizing strains could be discriminated from strains in patients with bloodstream infections, including patients with sepsis and septic shock. Isolates associated with colonization might have sRNAs with target expression different from those of disease isolates. Monitoring expression of RNAIII and sprD could help determine severity of bloodstream infections. PMID:27224202

  12. Antibiotic resistant Staphylococcus aureus: a paradigm of adaptive power

    PubMed Central

    de Lencastre, Herminia; Oliveira, Duarte; Tomasz, Alexander

    2009-01-01

    Summary Nothing documents better the spectacular adaptive capacity of Staphylococcus aureus than the response of this important human and animal pathogen to the introduction of antimicrobial agents into the clinical environment. The effectiveness of penicillin introduced in the early 1940s was virtually annulled within a decade due to the plasmid epidemics that spread the ß-lactamase gene through the entire species of S. aureus. In 1960 within one to two years of the introduction of penicillinase resistant ß-lactams (methicillin), methicillin resistant S. aureus (MRSA) strains were identified in clinical specimens. By the 1980s, epidemic clones of MRSA acquired multidrug resistant traits and spread worldwide to become one of the most important causative agents of hospital acquired infections. In the early 2000s, MRSA strains carrying the Tn1546 transposon-based enterococcal vancomycin resistant mechanism were identified in clinical specimens, bringing the specter of a totally resistant bacterial pathogen closer to reality. Then, in the late 1990s, just as effective hygienic and antibiotic use policies managed to bring down the frequency of MRSA in hospitals of several countries, MRSA strains began to show up in the community. PMID:17921044

  13. Beta-Hemolysin Promotes Skin Colonization by Staphylococcus aureus

    PubMed Central

    Katayama, Yuki; Sekine, Miwa; Fukuda, Minoru; Hiramatsu, Keiichi

    2013-01-01

    Colonization by Staphylococcus aureus is a characteristic feature of several inflammatory skin diseases and is often followed by epidermal damage and invasive infection. In this study, we investigated the mechanism of skin colonization by a virulent community-acquired methicillin-resistant S. aureus (CA-MRSA) strain, MW2, using a murine ear colonization model. MW2 does not produce a hemolytic toxin, beta-hemolysin (Hlb), due to integration of a prophage, ϕSa3mw, inside the toxin gene (hlb). However, we found that strain MW2 bacteria that had successfully colonized murine ears included derivatives that produced Hlb. Genome sequencing of the Hlb-producing colonies revealed that precise excision of prophage ϕSa3mw occurred, leading to reconstruction of the intact hlb gene in their chromosomes. To address the question of whether Hlb is involved in skin colonization, we constructed MW2-derivative strains with and without the Hlb gene and then subjected them to colonization tests. The colonization efficiency of the Hlb-producing mutant on murine ears was more than 50-fold greater than that of the mutant without hlb. Furthermore, we also showed that Hlb toxin had elevated cytotoxicity for human primary keratinocytes. Our results indicate that S. aureus Hlb plays an important role in skin colonization by damaging keratinocytes, in addition to its well-known hemolytic activity for erythrocytes. PMID:23292775

  14. Persister formation in Staphylococcus aureus is associated with ATP depletion

    PubMed Central

    Conlon, Brian P.; Rowe, Sarah E.; Gandt, Autumn Brown; Nuxoll, Austin S.; Donegan, Niles P.; Zalis, Eliza A.; Clair, Geremy; Adkins, Joshua N.; Cheung, Ambrose L.; Lewis, Kim

    2016-01-01

    Persisters are dormant phenotypic variants of bacterial cells that are tolerant to killing by antibiotics1. Persisters are associated with chronic infections and antibiotic treatment failure1–3. In Escherichia coli, toxin/antitoxin (TA) modules have been linked to persister formation4–6. The mechanism of persister formation in Gram-positive bacteria is unknown. Staphylococcus aureus is a major human pathogen, responsible for a variety of chronic and relapsing infections such as osteomyelitis, endocarditis and infections of implanted devices. Deleting TA modules in S. aureus did not affect the level of persisters. Here we show that S. aureus persisters are produced due to a stochastic entrance into stationary phase accompanied by a drop in intracellular ATP. Cells expressing stationary state markers are present throughout the growth phase, increasing in frequency with cell density. Cell sorting revealed that expression of stationary markers is associated with a 100–1000 fold increase in the likelihood of survival to antibiotic challenge. The ATP level of the cell is predictive of bactericidal antibiotic efficacy and explains bacterial tolerance to antibiotics. PMID:27398229

  15. Factors Affecting the Persistence of Staphylococcus aureus on Fabrics

    PubMed Central

    Wilkoff, Lee J.; Westbrook, Louise; Dixon, Glen J.

    1969-01-01

    The persistence of Staphylococcus aureus (Smith) on wool blanket, wool gabardine, cotton sheeting, cotton knit jersey, cotton terry cloth, and cotton wash-and-wear fabrics was studied. The fabrics were exposed to bacterial populations by three methods: direct contact, aerosol, and a lyophilized mixture of bacteria and dust having a high content of textile fibers. The contaminated fabrics were held in 35 or 78% relative humidities at 25 C. In general, the persistence time of S. aureus populations on fabrics held in 35% relative humidity was substantially longer when the fabrics were contaminated by exposure to aerosolized cultures or to dust containing bacteria than when contaminated by direct contact. In a 78% relative humidity, bacterial populations on the fabrics persisted for substantially shorter periods of time regardless of the mode of contamination or fabric type. Cotton wash-and-wear fabric (treated with a modified triazone resin) was the material on which populations of S. aureus persisted for the shortest time. This organism retained its virulence for Swiss mice after being recovered from wool gabardine swatches held 4 weeks in 35% relative humidity and 6 weeks in 78% relative humidity. Images PMID:5775911

  16. Regulatory Adaptation of Staphylococcus aureus during Nasal Colonization of Humans

    PubMed Central

    Burian, Marc; Wolz, Christiane; Goerke, Christiane

    2010-01-01

    The nasopharynx is the main ecological niche of the human pathogen Staphylococcus aureus. Although colonization of the nares is asymptomatic, nasal carriage is a known risk factor for endogenous staphylococcal infection. We quantified S. aureus mRNA levels in nose swabs of persistent carriers to gain insight into the regulatory adaptation of the bacterium to the nasal environment. We could elucidate a general response of the pathogen to the surrounding milieu independent of the strain background or the human host. Colonizing bacteria preferentially express molecules necessary for tissue adherence or immune-evasion whereas toxins are down regulated. From the analysis of regulatory loci we found evidence for a predominate role of the essential two-component system WalKR of S. aureus. The results suggest that during persistent colonization the bacteria are metabolically active with a high cell surface turnover. The increased understanding of bacterial factors that maintain the colonization state can open new therapeutic options to control nasal carriage and subsequent infections. PMID:20386721

  17. Overproduction of Type 8 Capsular Polysaccharide Augments Staphylococcus aureus Virulence

    PubMed Central

    Luong, Thanh T.; Lee, Chia Y.

    2002-01-01

    Type 8 capsular polysaccharide (CP8) is the most prevalent capsule type in clinical isolates of Staphylococcus aureus. However, its role in virulence has not been clearly defined. CP8 strains such as strain Becker produce a small amount of capsule on their surface in vitro. In contrast, CP1 strains such as strain M produce a large amount of capsule, which has been shown to be an important antiphagocytic virulence factor. The cap8 and cap1 operons, required for the synthesis of CP8 and CP1, respectively, have been cloned and sequenced. To test whether CP8 contributes to the pathogenesis of S. aureus, we replaced the weak native promoter of the cap8 operon in strain Becker with the strong constitutive promoter of the cap1 operon of strain M. The resultant strain, CYL770, synthesized cap8-specific mRNA at a level about sevenfold higher than that in the parent strain. Remarkably, the CYL770 strain produced about 80-fold more CP8. In a mouse infection model of bacteremia, the CP8-overproducing strain persisted longer in the bloodstream, the liver, and the spleen in mice than the parent strain. In addition, strain CYL770 was more resistant to ospsonophagocytosis in vitro by human polymorphonuclear leukocytes. These results indicate that CP8 is an antiphagocytic virulence factor of S. aureus. PMID:12065477

  18. Tea tree oil-induced transcriptional alterations in Staphylococcus aureus.

    PubMed

    Cuaron, Jesus A; Dulal, Santosh; Song, Yang; Singh, Atul K; Montelongo, Cesar E; Yu, Wanqin; Nagarajan, Vijayaraj; Jayaswal, Radheshyam K; Wilkinson, Brian J; Gustafson, John E

    2013-03-01

    Tea tree oil (TTO) is a steam distillate of Melaleuca alternifolia that demonstrates broad-spectrum antibacterial activity. This study was designed to document how TTO challenge influences the Staphylococcus aureus transcriptome. Overall, bioinformatic analyses (S. aureus microarray meta-database) revealed that both ethanol and TTO induce related transcriptional alterations. TTO challenge led to the down-regulation of genes involved with energy-intensive transcription and translation, and altered the regulation of genes involved with heat shock (e.g. clpC, clpL, ctsR, dnaK, groES, groEL, grpE and hrcA) and cell wall metabolism (e.g. cwrA, isaA, sle1, vraSR and vraX). Inactivation of the heat shock gene dnaK or vraSR which encodes a two-component regulatory system that responds to peptidoglycan biosynthesis inhibition led to an increase in TTO susceptibility which demonstrates a protective role for these genes in the S. aureus TTO response. A gene (mmpL) encoding a putative resistance, nodulation and cell division efflux pump was also highly induced by TTO. The principal antimicrobial TTO terpene, terpinen-4-ol, altered ten genes in a transcriptional direction analogous to TTO. Collectively, this study provides additional insight into the response of a bacterial pathogen to the antimicrobial terpene mixture TTO.

  19. Biofilm-forming capacity of Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa from ocular infections.

    PubMed

    Hou, Wenbo; Sun, Xuguang; Wang, Zhiqun; Zhang, Yang

    2012-08-17

    To investigate the biofilm-forming capacity of Staphylococcus epidermidis, Staphylococcus aureus, and Pseudomonas aeruginosa from ocular infections. S. epidermidis strains, S. aureus strains, and P. aeruginosa strains were isolated from patients with ocular infections between 2009 and 2011. The biofilm-forming capacity of these bacteria was examined using Congo red agar (CRA) and microtiter plate assays. The biofilm-forming related genes, icaA, of S. epidermidis and S. aureus, and pslA, of P. aeruginosa, were detected using PCR. Additionally, the morphology of biofilms was observed using a scanning electron microscopy (SEM). Of the isolated S. epidermidis strains, 34.38% were CRA positive, 28.13% were adherence positive using the microtiter plate assay, and 40.63% carried the icaA gene. Of the isolated S. aureus strains, 55.56% were CRA positive, 51.90% were adherence positive, and 11.11% carried the icaA gene. None of the P. aeruginosa strains were phenotypic positive using CRA and microtiter plate assays, whereas 31.03% contained the pslA gene. There were significant differences between the three species when the biofilm-forming capacity of the strains was compared using the CRA method (P < 0.01) and the microtiter plate assay method (P < 0.01). Ophthalmic isolates of S. epidermidis and S. aureus could produce biofilms in vitro, whereas clinical strains of P. aeruginosa could not. The bacterial strains possess the genetic ability to produce biofilms, but that does not necessarily mean that biofilms will be produced. The knowledge of the process of bacterial adhesion suggests that a timely and appropriate intervention strategy be implemented in the early stages of biofilm-mediated infections.

  20. Improving the safety of Staphylococcus aureus polyvalent phages by their production on a Staphylococcus xylosus strain.

    PubMed

    El Haddad, Lynn; Ben Abdallah, Nour; Plante, Pier-Luc; Dumaresq, Jeannot; Katsarava, Ramaz; Labrie, Steve; Corbeil, Jacques; St-Gelais, Daniel; Moineau, Sylvain

    2014-01-01

    Team1 (vB_SauM_Team1) is a polyvalent staphylococcal phage belonging to the Myoviridae family. Phage Team1 was propagated on a Staphylococcus aureus strain and a non-pathogenic Staphylococcus xylosus strain used in industrial meat fermentation. The two Team1 preparations were compared with respect to their microbiological and genomic properties. The burst sizes, latent periods, and host ranges of the two derivatives were identical as were their genome sequences. Phage Team1 has 140,903 bp of double stranded DNA encoding for 217 open reading frames and 4 tRNAs. Comparative genomic analysis revealed similarities to staphylococcal phages ISP (97%) and G1 (97%). The host range of Team1 was compared to the well-known polyvalent staphylococcal phages phi812 and K using a panel of 57 S. aureus strains collected from various sources. These bacterial strains were found to represent 18 sequence types (MLST) and 14 clonal complexes (eBURST). Altogether, the three phages propagated on S. xylosus lysed 52 out of 57 distinct strains of S. aureus. The identification of phage-insensitive strains underlines the importance of designing phage cocktails with broadly varying and overlapping host ranges. Taken altogether, our study suggests that some staphylococcal phages can be propagated on food-grade bacteria for biocontrol and safety purposes.

  1. Improving the Safety of Staphylococcus aureus Polyvalent Phages by Their Production on a Staphylococcus xylosus Strain

    PubMed Central

    El Haddad, Lynn; Ben Abdallah, Nour; Plante, Pier-Luc; Dumaresq, Jeannot; Katsarava, Ramaz; Labrie, Steve; Corbeil, Jacques; St-Gelais, Daniel; Moineau, Sylvain

    2014-01-01

    Team1 (vB_SauM_Team1) is a polyvalent staphylococcal phage belonging to the Myoviridae family. Phage Team1 was propagated on a Staphylococcus aureus strain and a non-pathogenic Staphylococcus xylosus strain used in industrial meat fermentation. The two Team1 preparations were compared with respect to their microbiological and genomic properties. The burst sizes, latent periods, and host ranges of the two derivatives were identical as were their genome sequences. Phage Team1 has 140,903 bp of double stranded DNA encoding for 217 open reading frames and 4 tRNAs. Comparative genomic analysis revealed similarities to staphylococcal phages ISP (97%) and G1 (97%). The host range of Team1 was compared to the well-known polyvalent staphylococcal phages phi812 and K using a panel of 57 S. aureus strains collected from various sources. These bacterial strains were found to represent 18 sequence types (MLST) and 14 clonal complexes (eBURST). Altogether, the three phages propagated on S. xylosus lysed 52 out of 57 distinct strains of S. aureus. The identification of phage-insensitive strains underlines the importance of designing phage cocktails with broadly varying and overlapping host ranges. Taken altogether, our study suggests that some staphylococcal phages can be propagated on food-grade bacteria for biocontrol and safety purposes. PMID:25061757

  2. Cholecystokinin protects rats against sepsis induced by Staphylococcus aureus.

    PubMed

    Zuelli, Fabiana Maria das Graças Corsi; Cárnio, Evelin Capellari; Saia, Rafael Simone

    2014-06-01

    Staphylococcus aureus is a Gram-positive bacteria described as an important causative agent of sepsis. The contact between host leukocytes and bacteria activates the innate immune response. Nitric oxide, tumor necrosis factor (TNF)-α and interleukin (IL)-1β play a key role in increasing microbicidal activity and controlling cell influx into infectious focus. Contrarily, IL-10 acts as an anti-inflammatory cytokine and bacterial killing suppressor. Immunoregulatory properties have also been attributed to hormones, including cholecystokinin (CCK). CCK protects cardiovascular function and inhibits the inflammatory response induced by lipopolysaccharide, product derived from Gram-negative bacteria. Nevertheless, the role of CCK during Gram-positive infection remains a literature gap. Our aims were to investigate whether CCK protects rats against bacterial dissemination during sepsis induced by S. aureus. We determined whether CCK modulates local and systemic inflammatory response, as well as the cell migration into the infectious focus and the bactericidal capacity of leukocytes. Our results revealed that proglumide (nonselective CCK receptor antagonist) pretreated rats showed higher bacterial counts in blood and peritoneal lavage fluid (PLF) and reduced TNF-α and IL-10 levels in PLF. Moreover, the dissemination of S. aureus may be related to the failure of neutrophil and macrophage migration into the peritoneal cavity. Also, CCK improved the phagocytic and bactericidal ability of these inflammatory cells. Noteworthy is that the adoptive transfer of CCK-treated neutrophils and macrophages in septic rats improved immune defense, reducing bacterial number in blood and PLF. All together, our study clearly demonstrates an important protective role of CCK against sepsis induced by S. aureus.

  3. Distribution of food-borne Staphylococcus aureus enterotoxin genes.

    PubMed

    Hu, W D

    2016-01-29

    We identified and analyzed 5 new-type enterotoxin genes, including SEj, SEl, SEq, SEm, and SEr, to explore the distribution of 5 enterotoxin genes in Staphylococcus aureus of different origins as well as their correlations and differences. We examined the distribution of the S. aureus enterotoxin genes and their pathogenic mechanisms. A total of 660 specimens were collected from January 2011 to December 2014, and 217 strains of S. aureus were isolated. The template DNA of S. aureus was extracted. The Primer6.0 and Oligo7 software were used to design and synthesize polymerase chain reaction primers. Amplification results were analyzed by electrophoresis, and the amplification products were recovered and sequenced. Thirty-six bacterial strains contained the SEj gene (16.6%), including 15, 8, 8, 4, and 1 strains in fresh meat, quick-frozen food, raw milk, human purulent tissue, and living environment, respectively. Thirty-one bacterial strains contained the SEr gene (14.3%), including 16, 9, and 6 strains in fresh meat, quick-frozen food, and raw milk, respectively. Twenty-one bacterial strains contained the enterotoxin SEq gene (9.7%), including 8, 6, 6, and 1 strains in fresh meat, quick-frozen food, raw milk, and human purulent tissue, respectively. No SEm and SEl genes were detected. Different types of foods carry different types of enterotoxins, providing a basis for quick tracing for food poisoning. Three enterotoxin genes, SEj, SEr, and SEq, showed the highest carrier rate in quick-frozen food. It is imperative to improve their detection in quick-frozen food.

  4. Applying Convergent Immunity to Innovative Vaccines Targeting Staphylococcus aureus

    PubMed Central

    Yeaman, Michael R.; Filler, Scott G.; Schmidt, Clint S.; Ibrahim, Ashraf S.; Edwards, John E.; Hennessey, John P.

    2014-01-01

    Recent perspectives forecast a new paradigm for future “third generation” vaccines based on commonalities found in diverse pathogens or convergent immune defenses to such pathogens. For Staphylococcus aureus, recurring infections and a limited success of vaccines containing S. aureus antigens imply that native antigens induce immune responses insufficient for optimal efficacy. These perspectives exemplify the need to apply novel vaccine strategies to high-priority pathogens. One such approach can be termed convergent immunity, where antigens from non-target organisms that contain epitope homologs found in the target organism are applied in vaccines. This approach aims to evoke atypical immune defenses via synergistic processes that (1) afford protective efficacy; (2) target an epitope from one organism that contributes to protective immunity against another; (3) cross-protect against multiple pathogens occupying a common anatomic or immunological niche; and/or (4) overcome immune subversion or avoidance strategies of target pathogens. Thus, convergent immunity has a potential to promote protective efficacy not usually elicited by native antigens from a target pathogen. Variations of this concept have been mainstays in the history of viral and bacterial vaccine development. A more far-reaching example is the pre-clinical evidence that specific fungal antigens can induce cross-kingdom protection against bacterial pathogens. This trans-kingdom protection has been demonstrated in pre-clinical studies of the recombinant Candida albicans agglutinin-like sequence 3 protein (rAls3) where it was shown that a vaccine containing rAls3 provides homologous protection against C. albicans, heterologous protection against several other Candida species, and convergent protection against several strains of S. aureus. Convergent immunity reflects an intriguing new approach to designing and developing vaccine antigens and is considered here in the context of vaccines to target S

  5. DNA Macroarray for Identification and Typing of Staphylococcus aureus Isolates

    PubMed Central

    Trad, Salim; Allignet, Jeanine; Frangeul, Lionel; Davi, Marilyne; Vergassola, Massimo; Couve, Elisabeth; Morvan, Anne; Kechrid, Amel; Buchrieser, Carmen; Glaser, Philippe; El Solh, Névine

    2004-01-01

    A DNA macroarray containing 465 intragenic amplicons was designed to identify Staphylococcus aureus at the species level and to type S. aureus isolates. The genes selected included those encoding (i) S. aureus-specific proteins, (ii) staphylococcal and enterococcal proteins mediating antibiotic resistance and factors involved in their expression, (iii) putative virulence proteins and factors controlling their expression, and (iv) proteins produced by mobile elements. The macroarray was hybridized with the cellular DNAs of 80 S. aureus clinical isolates that were previously typed by analyses of their antibiograms and SmaI patterns. The set selected contained unrelated, endemic, and outbreak-related isolates belonging to 45 SmaI genotypes. In a gene content dendrogram, the 80 isolates were distributed into 52 clusters. The outbreak-related isolates were linked in the same or a closely related cluster(s). Clustering based on gene content provided a better discrimination than SmaI pattern analysis for the tested mecA+ isolates that were endemic to Europe. All of the antibiotic resistance genes detected could be correlated with their corresponding phenotypes, except for one isolate which carried a mecA gene without being resistant. The 16 isolates responsible for bone infections were distinguishable from the 12 isolates from uninfected nasal carriers by a significantly higher prevalence of the sdrD gene coding for a putative SD (serine-aspartate) adhesin (in 15 and 7 isolates, respectively). In conclusion, the macroarray designed for this study offers an attractive and rapid typing method which has the advantage of providing additional information concerning the gene content of the isolate of interest. PMID:15131170

  6. Exclusive Staphylococcus aureus throat carriage: at-risk populations.

    PubMed

    Mertz, Dominik; Frei, Reno; Periat, Nadine; Zimmerli, Melanie; Battegay, Manuel; Flückiger, Ursula; Widmer, Andreas F

    2009-01-26

    Approximately 25% of Staphylococcus aureus carriers have exclusive throat carriage. We aimed to identify the populations at risk for exclusive throat carriage to improve sensitivity to detect carriers. Four groups underwent nasal and throat screening for S. aureus. Three groups of individuals in the community (n = 2632) with different estimated levels of exposure to the health care system (HCS) were screened, including 1500 healthy blood donors, 498 patients from a school of dental medicine, and 634 health care workers (HCWs) at a trade fair. The fourth group comprised in-hospital patients and HCWs (n = 832) and was considered the group with the highest estimated exposure to the HCS. As a primary outcome, we analyzed risk factors for exclusive throat carriage in exclusive throat carriers vs all nasal carriers. Of 3464 individuals screened, 428 (12.4%) had exclusive throat carriage, and 1260 (36.4%) had carriage in the nares only or in the nares and the throat. The most important independent risk factor for exclusive throat carriage was age 30 years or younger (odds ratio, 1.66; P < .001). Exposure to the HCS was a significant protective factor for exclusive throat carriage (odds ratio, 0.67; P = .001). Healthy blood donors were almost twice as likely to have exclusive throat carriage than in-hospital patients and HCWs (30.2% vs 18.4% of all carriers, P < .001). Absence of exposure to the HCS and younger age predicted exclusive throat carriers, a population at high risk for community-onset methicillin-resistant S. aureus. Screening for S. aureus should include swabs from the anterior nares and from the throat to improve the likelihood of detecting carriers.

  7. Vaccination against Staphylococcus aureus mastitis in two Swedish dairy herds.

    PubMed

    Landin, Håkan; Mörk, Marie Jansson; Larsson, Maria; Waller, Karin Persson

    2015-11-25

    Staphylococcus aureus is a common udder pathogen in dairy cows, and may cause severe mastitis problems in some herds. In herds where normal control measures are not successful, vaccination might be an additional tool to use if sufficiently efficient. The aim of the present study was to evaluate the efficacy of a commercially available vaccine (Startvac(®), Hipra, Spain) in two commercial Swedish dairy herds where the control programs for S. aureus mastitis had been unsuccessful. Within each herd cows were randomly assigned to vaccine or control groups, and effects on udder health and milk production during 120 days after calving, and survival during the following lactation were evaluated. A field study was performed in two high producing Swedish herds having approximately 600 (herd A) and 200 (herd B) cows. During 12 months, cows with odd numbers were vaccinated three times around calving according to label protocol, while cows with even numbers constituted the not vaccinated control group. Quarter milk samples for bacteriological culturing were collected from all cases of clinical and subclinical mastitis. The outcome was evaluated during 120 days after calving using data on SCC and daily milk yield at monthly milk recordings, and incidence of mastitis due to S. aureus, coagulase-negative staphylococci, streptococci and coliforms. Cow survival throughout lactation was also studied. In herd A, 239 and 240 cows were included in the vaccinated and control groups, respectively. Corresponding numbers for herd B was 126 and 151 cows. Significant differences between vaccinated and control groups were not found in any of the parameters investigated. Vaccination with a commercial polyvalent vaccine did not have any beneficial effects on udder health, milk production or survival in two commercial dairy herds with mastitis problems due to S. aureus.

  8. Novel rat tail discitis model using bioluminescent Staphylococcus aureus.

    PubMed

    Bostian, Phillip A; Karnes, Jonathan M; Cui, Shari; Robinson, Lisa J; Daffner, Scott D; Witt, Michelle R; Emery, Sanford E

    2016-12-05

    Management of spondylodiscitis is a challenging clinical problem requiring medical and surgical treatment strategies. The purpose of this study was to establish a rat model of spondylodiscitis that utilizes bioluminescent Staphylococcus aureus (S. aureus), thus permitting in vivo surveillance of infection intensity. Inocula of the bioluminescent S. aureus strain XEN36 were created in concentrations of 10(2) CFU/0.1 ml, 10(4)  CFU/0.1 ml, and 10(6)  CFU/0.1 ml. Three groups of rats were injected with the bacteria in the most proximal intervertebral tail segment. The third most proximal tail segment was injected with saline as a control. Bioluminescence was measured at baseline, 3 days, and weekly for a total of 6 weeks. Detected bioluminescence for each group peaked at day 3 and returned to baseline in 21 days. The average intensity was highest for the experimental group injected with the most concentrated bacterial solution (10(6)  CFU/0.1 ml). Radiographic analysis revealed loss of intervertebral disc space and evidence of osseous bridging. Saline-injected spaces exhibited no decrease in intervertebral spacing as compared to distal sites. Histologic analysis revealed neutrophilic infiltrates, destruction of the annulus fibrosus and nucleus pulposus, destruction of vertebral endplates, and osseous bridging. Saline-injected discs exhibited preserved annulus fibrosus and nucleus pulposus on histology. This study demonstrates that injection of bioluminescent S. aureus into the intervertebral disc of a rat tail is a viable animal model for spondylodiscitis research. This model allows for real-time, in vivo quantification of infection intensity, which may decrease the number of animals required for infection studies of the intervertebral disc. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  9. Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters.

    PubMed

    Plano, Lisa R W; Garza, Anna C; Shibata, Tomoyuki; Elmir, Samir M; Kish, Jonathan; Sinigalliano, Christopher D; Gidley, Maribeth L; Miller, Gary; Withum, Kelly; Fleming, Lora E; Solo-Gabriele, Helena M

    2011-01-06

    Staphylococcus aureus including methicillin resistant S. aureus, MRSA, are human colonizing bacteria that commonly cause opportunistic infections primarily involving the skin in otherwise healthy individuals. These infections have been linked to close contact and sharing of common facilities such as locker rooms, schools and prisons Waterborne exposure and transmission routes have not been traditionally associated with S. aureus infections. Coastal marine waters and beaches used for recreation are potential locations for the combination of high numbers of people with close contact and therefore could contribute to the exposure to and infection by these organisms. The primary aim of this study was to evaluate the amount and characteristics of the shedding of methicillin sensitive S. aureus, MSSA and MRSA by human bathers in marine waters. Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA. This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly demonstrate that adults and toddlers shed their colonizing

  10. Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters

    PubMed Central

    2011-01-01

    Background Staphylococcus aureus including methicillin resistant S. aureus, MRSA, are human colonizing bacteria that commonly cause opportunistic infections primarily involving the skin in otherwise healthy individuals. These infections have been linked to close contact and sharing of common facilities such as locker rooms, schools and prisons Waterborne exposure and transmission routes have not been traditionally associated with S. aureus infections. Coastal marine waters and beaches used for recreation are potential locations for the combination of high numbers of people with close contact and therefore could contribute to the exposure to and infection by these organisms. The primary aim of this study was to evaluate the amount and characteristics of the shedding of methicillin sensitive S. aureus, MSSA and MRSA by human bathers in marine waters. Results Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA. Conclusions This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly demonstrate that adults and

  11. [Classification of haematogenous and post-traumatic osteomyelitis].

    PubMed

    Schmidt, H G K; Diefenbeck, M; Krenn, V; Abitzsch, D; Militz, M; Tiemann, A H; Haustedt, N; Gückel, P; Bühler, M; Gerlach, U-J

    2014-08-01

    A classification of osteomyelitis must reflect the complexity of the disease and, moreover, provide conclusions for the treatment. The classification is based on the following eight parameters: source of infection (OM [osteomyelitis]/OT [post-traumatic OM]), anatomic region, stability of affected bone (continuity of bone), foreign material (internal fixation, prosthesis), range of infection (involved structures), activity of infection (acute, chronic, quiescent), causative microbes (unspecific and specific bacteria, fungi) and comorbidity (immunosuppressive diseases, general and local). In the long version of the classification, which was designed for scientific studies, the parameters are named by capital letters and specified by Arabic numbers, e.g., an acute, haematogenous osteomyelitis of a femur in an adolescent with diabetes mellitus, caused by Staphylococcus aureus, multi-sensible is coded as: OM2 Lo33 S1a M1 In1d Aa1 Ba2a K2a. The letters and numbers can be found in clearly arranged tables or calculated by a freely available grouper on the internet (www.osteomyelitis.exquit.net). An equally composed compact version of the classification for clinical use includes all eight parameters, but without further specification. The above-mentioned example in the compact version is: OM 3 S a Ba2 K2. The short version of the classification uses only the first six parameters and excludes causative microbes and comorbidity. The above mentioned example in the short version is: OM 3 S a. The long version of the classification describes an osteomyelitis in every detail. The complexity of the patient's disease is clearly reproducible and can be used for scientific comparisons. The for clinical use suggested compact and short versions of the classification include all important characteristics of an osteomyelitis, can be composed quickly and distinctly with the help of tables and provide conclusions for the individual treatment. The freely available grouper (www

  12. Fosfomycin for the initial treatment of acute haematogenous osteomyelitis

    PubMed Central

    Corti, N; Sennhauser, F; Stauffer, U; Nadal, D

    2003-01-01

    Background and Aims: At our institution there has been a dichotomous antimicrobial treatment behaviour for acute haematogenous osteomyelitis (AHOM) since 1984. The surgical department favoured fosfomycin as initial choice and the medical department ß lactams. We aimed to compare the performance of both strategies. Methods: Data from patients discharged with the diagnosis of AHOM between January 1984 and January 1998 were gathered from the charts by means of a questionnaire. Patients receiving fosfomycin treatment (FT) were compared with those receiving fosfomycin plus other antimicrobials (FT+) and those receiving no fosfomycin treatment (NFT). Results: A total of 103 patients aged 0.1–15.5 years (mean 6.5, median 6.9) with AHOM received no surgical treatment initially. In 23 (22.3%) FT was instilled initially, in 47 (45.6%) FT+, and in 33 (32.0%) NFT. The pathogen was established in 30%, 36%, and 42% of FT, FT+, and NFT patients, respectively, Staphylococcus aureus being the predominant isolate. Mean C reactive protein levels and erythrocyte sedimentation rates normalised in all treatment groups after two and four weeks, respectively. The mean duration of intravenous antimicrobial treatment in FT patients was 2.5 weeks, in FT+ patients 3.1 weeks, and in NFT patients 3.8 weeks (p < 0.05), whereas the mean duration of intravenous plus oral treatment was comparable (7.1 v 6.8 v 6.5 weeks). Conclusions: The leucocyte penetrating fosfomycin performed similarly to extracellular ß lactams in the treatment of AHOM. Intravenous treatment for longer than 2.5 weeks offered no advantage. PMID:12765918

  13. Temporal and stochastic control of Staphylococcus aureus biofilm development.

    PubMed

    Moormeier, Derek E; Bose, Jeffrey L; Horswill, Alexander R; Bayles, Kenneth W

    2014-10-14

    Biofilm communities contain distinct microniches that result in metabolic heterogeneity and variability in gene expression. Previously, these niches were visualized within Staphylococcus aureus biofilms by observing differential expression of the cid and lrg operons during tower formation. In the present study, we examined early biofilm development and identified two new stages (designated "multiplication" and "exodus") that were associated with changes in matrix composition and a distinct reorganization of the cells as the biofilm matured. The initial attachment and multiplication stages were shown to be protease sensitive but independent of most cell surface-associated proteins. Interestingly, after 6 h of growth, an exodus of the biofilm population that followed the transition of the biofilm to DNase I sensitivity was demonstrated. Furthermore, disruption of the gene encoding staphylococcal nuclease (nuc) abrogated this exodus event, causing hyperproliferation of the biofilm and disrupting normal tower development. Immediately prior to the exodus event, S. aureus cells carrying a nuc::gfp promoter fusion demonstrated Sae-dependent expression but only in an apparently random subpopulation of cells. In contrast to the existing model for tower development in S. aureus, the results of this study suggest the presence of a Sae-controlled nuclease-mediated exodus of biofilm cells that is required for the development of tower structures. Furthermore, these studies indicate that the differential expression of nuc during biofilm development is subject to stochastic regulatory mechanisms that are independent of the formation of metabolic microniches. Importance: In this study, we provide a novel view of four early stages of biofilm formation by the human pathogen Staphylococcus aureus. We identified an initial nucleoprotein matrix during biofilm development that is DNase I insensitive until a critical point when a nuclease-mediated exodus of the population is induced prior

  14. Population genetic structures of Staphylococcus aureus isolates from cats and dogs in Japan.

    PubMed

    Sasaki, Takashi; Tsubakishita, Sae; Tanaka, Yoshikazu; Ohtsuka, Masayuki; Hongo, Isamu; Fukata, Tsuneo; Kabeya, Hidenori; Maruyama, Soichi; Hiramatsu, Keiichi

    2012-06-01

    We determined the population genetic structures of feline and canine Staphylococcus aureus strains in Japan by multilocus sequence typing (MLST). Ecological analyses suggested that multiple feline-related S. aureus clones, including ST133, naturally occur as commensals and can cause endogenous infections in felines. In contrast, S. aureus populations do not likely include any clone that exhibits tropism in domestic dogs. Even if S. aureus infections occur in dogs, the pathologies are likely exogenous infections.

  15. Staphylococcus epidermidis ΔSortase A strain elicits protective immunity against Staphylococcus aureus infection.

    PubMed

    Tan, Chao; Wang, Jun; Hu, Yifang; Wang, Peng; Zou, Lili

    2017-01-01

    Staphylococcus aureus and Staphylococcus epidermidis are two of the most significant opportunistic human pathogens, causing medical implant and nosocomial infections worldwide. These bacteria contain surface proteins that play crucial roles in multiple biological processes. It has become apparent that they have evolved a number of unique mechanisms by which they can immobilise proteins on their surface. Notably, a conserved cell membrane-anchored enzyme, sortase A (SrtA), can catalyse the covalent attachment of precursor bacterial cell wall-attached proteins to peptidoglycan. Considering its indispensable role in anchoring substrates to the cell wall and its effects on virulence, SrtA has attracted great attention. In this study, a 549-bp gene was cloned from a pathogenic S. epidermidis strain, YC-1, which shared high identity with srtA from other Staphylococcus spp. A mutant strain, YC-1ΔsrtA, was then constructed by allelic exchange mutagenesis. The direct survival rate assay suggested that YC-1ΔsrtA had a lower survival capacity in healthy mice blood compare with the wild-type strain, indicating that the deletion of srtA affects the virulence and infectious capacity of S. epidermidis YC-1. YC-1ΔsrtA was then administered via intraperitoneal injection and it provided a relative percent survival value of 72.7 % in mice against S. aureus TC-1 challenge. These findings demonstrate the possbility that YC-1ΔsrtA might be used as a live attenuated vaccine to produce cross-protection against S. aureus.

  16. Preparation of Cell Wall Antigens of Staphylococcus aureus

    PubMed Central

    Kowalski, J. J.; Tipper, Donald J.; Berman, David T.

    1970-01-01

    Cell walls were prepared from Staphylococcus aureus strains Copenhagen and 263 by high-speed mixing in the presence of glass beads followed by differential centrifugation. Insoluble peptidoglycan complexes were derived from cell walls by extraction of teichoic acid with 10% trichloroacetic acid. Intact teichoic acid was prepared from each strain by digestion of cell walls with lysostaphin and isolated by column chromatography. Soluble glycopeptide (peptidoglycan in which only the glycan has been fragmented) and the stable complex of teichoic acid with glycopeptide were prepared by digestion of cell walls with Chalaropsis B endo-N-acetylmuramidase and were separated by column chromatography. Amino acid and amino sugar contents of walls and subunits of walls were comparable to those reported by others. Images PMID:16557799

  17. Inactivation of Staphylococcus aureus in water by pulsed spark discharge.

    PubMed

    Zheng, Jiansheng

    2017-09-04

    A pulsed spark plasma discharge system was developed and tested as an energy efficient water sterilization method. A 5 log10 reduction on Staphylococcus aureus concentration of 10(8) CFU/ml was obtained. Complete inactivation was achieved for concentration of 10(6) CFU/ml. Of the various factors generated by an underwater spark discharge, ultraviolet radiation plays a major role. The inactivation was completely suppressed by the addition of 30 mg/L of a soluble sunscreen, Benzophenone-9. Results obtained using the pulsed spark plasma discharge showed that this system has several advantages, such as high energy efficiency, absence of harmful by-products and portability, over the conventional sterilization methods.

  18. Bilateral sudden sensorineural hearing loss in Staphylococcus aureus endocarditis.

    PubMed

    Lau, Joanne Wai Ling; Ceranic, Borka; Harris, Robert; Timehin, Elwina

    2015-09-14

    This case highlights the diagnostic challenges in patients presenting with bilateral sudden sensorinueral hearing loss (SNHL). The aetiology of bilateral sudden SNHL may span several medical disciplines. Therefore, clinicians should be mindful of such presentations, and consider aetiologies beyond otological and neurological causes. We present a case of a previously healthy 51-year-old woman who presented with coryzal symptoms and sudden audiovestibular failure. Examination revealed fever, tachycardia, bilateral profound hearing loss and nystagmus. Following investigations, an initial working diagnosis of vasculitis was made. Later, blood cultures revealed methicillin-sensitive Staphylococcus aureus (MSSA) and a transoesophageal echocardiogram confirmed endocarditis. The patient made a good recovery, but the hearing loss was permanent and managed with a cochlear implant.

  19. Personal hygiene and methicillin-resistant Staphylococcus aureus infection.

    PubMed

    Turabelidze, George; Lin, Mei; Wolkoff, Barbara; Dodson, Douglas; Gladbach, Stephen; Zhu, Bao-Ping

    2006-03-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infections outside the healthcare setting are an increasing concern. We conducted a case-control study to investigate an MRSA outbreak during 2002-2003 in a Missouri prison and focused on hygiene factors. Information on sociodemographic characteristics, medical history, and hygiene practices of study participants was collected by interview and medical record review. Logistic regression was used to evaluate MRSA infection in relation to hygiene factors individually and as a composite hygiene score; potential confounding factors were controlled. Selected MRSA isolates were analyzed by pulsed-field gel electrophoresis (PFGE). MRSA infection was significantly associated with a low composite hygiene score. Transmission among prison inmates appeared to be responsible for this outbreak. PFGE analysis showed that isolates were indistinguishable and associated with community-onset MRSA infections in other US prisons. Improving hygiene practices and environmental conditions may help prevent and interrupt future MRSA outbreaks in prison settings.

  20. Autophagy is a key tolerance mechanism during Staphylococcus aureus infection.

    PubMed

    Maurer, Katie; Torres, Victor J; Cadwell, Ken

    2015-01-01

    Defense strategies against infectious threats can be divided into resistance and tolerance mechanisms. Resistance mechanisms involve reduction of pathogen burden and include many established examples, one of them being the destruction of intracellular pathogens through autophagy (xenophagy). Tolerance mechanisms protect the host from damage caused by the pathogen or the immune response independent of pathogen load. The role of autophagy in maintaining homeostasis in response to environmental stress suggests that this pathway is involved in tolerance to a variety of infectious agents. However, demonstrating that autophagy promotes tolerance independent of its role in resistance has been a challenge, especially during infection by clinically relevant pathogens. We have found that autophagy protects against Staphylococcus aureus infection by maintaining tolerance toward a pore forming toxin secreted by the bacteria, α-toxin.

  1. Autophagy is a key tolerance mechanism during Staphylococcus aureus infection

    PubMed Central

    Maurer, Katie; Torres, Victor J; Cadwell, Ken

    2015-01-01

    Defense strategies against infectious threats can be divided into resistance and tolerance mechanisms. Resistance mechanisms involve reduction of pathogen burden and include many established examples, one of them being the destruction of intracellular pathogens through autophagy (xenophagy). Tolerance mechanisms protect the host from damage caused by the pathogen or the immune response independent of pathogen load. The role of autophagy in maintaining homeostasis in response to environmental stress suggests that this pathway is involved in tolerance to a variety of infectious agents. However, demonstrating that autophagy promotes tolerance independent of its role in resistance has been a challenge, especially during infection by clinically relevant pathogens. We have found that autophagy protects against Staphylococcus aureus infection by maintaining tolerance toward a pore forming toxin secreted by the bacteria, α-toxin. PMID:26046478

  2. Quorum Sensing Inhibitors for Staphylococcus aureus from Italian Medicinal Plants

    PubMed Central

    Quave, Cassandra L.; Plano, Lisa R.W.; Bennett, Bradley C.

    2010-01-01

    Morbidity and mortality estimates due to methicillin-resistant Staphylococcus aureus (MRSA) infections continue to rise. Therapeutic options are limited by antibiotic resistance. Anti-pathogenic compounds, which inhibit quorum sensing (QS) pathways, may be a useful alternative to antibiotics. Staphylococcal QS is encoded by the agr locus and is responsible for the production of δ-hemolysin. Quantification of δ-hemolysin found in culture supernatants permits the analysis of agr activity at the translational, rather than transcriptional, level. We employed RP-HPLC techniques to investigate the anti-QS activity of 168 extracts from 104 Italian plants through quantification of δ-hemolysin. Extracts from three medicinal plants (Ballota nigra, Castanea sativa, and Sambucus ebulus) exhibited a dose-dependent response in the production of δ-hemolysin, indicating strong anti-QS activity in a pathogenic MRSA isolate. PMID:20645243

  3. Antimicrobial Photodynamic Therapy for Methicillin-Resistant Staphylococcus aureus Infection

    PubMed Central

    Fu, Xiu-jun; Fang, Yong; Yao, Min

    2013-01-01

    Nowadays methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common multidrug resistant bacteria both in hospitals and in the community. In the last two decades, there has been growing concern about the increasing resistance to MRSA of the most potent antibiotic glycopeptides. MRSA infection poses a serious problem for physicians and their patients. Photosensitizer-mediated antimicrobial photodynamic therapy (PDT) appears to be a promising and innovative approach for treating multidrug resistant infection. In spite of encouraging reports of the use of antimicrobial PDT to inactivate MRSA in large in vitro studies, there are only few in vivo studies. Therefore, applying PDT in the clinic for MRSA infection is still a long way off. PMID:23555074

  4. Antibacterial effect of borage (Echium amoenum) on Staphylococcus aureus.

    PubMed

    Abolhassani, Mohsen

    2004-10-01

    Borage (Echium amoenum) is a large annual plant of the Boraginaceae family, which grows in most of Europe and in northern Iran. The borage flower is used as a medicinal herb in France and other countries. Iranian borage is used in traditional medicine for infectious diseases, flu and as an anti-febrile. We tested the aqueous extract of borage dried flowers in vitro for its antibacterial activity. The extract showed concentration-dependent antibacterial activity against Staphylococcus aureus 8327. This activity was heat resistant, but the activity of freeze-dried extract gradually diminished during a 90-day period. The traditional use of Iranian borage flowers for infectious diseases and for controlling fever appears to be justified.

  5. Colonization of Cimex lectularius with methicillin-resistant Staphylococcus aureus.

    PubMed

    Barbarin, Alexis M; Hu, Baofeng; Nachamkin, Irving; Levy, Michael Z

    2014-05-01

    A recent paper published by Lowe and Romney in Emerging Infectious Diseases titled, Bed bugs as Vectors for Drug-Resistant Bacteria has sparked a renewed interest in bed bug vector potential. We followed a pyrethroid resistant strain of the human bed bug (Cimex lectularius, L.) fed either human blood or human blood with added methicillin resistant Staphylococcus aureus (MRSA) for 9 days post-feeding. Results indicated that while the bed bug midgut is a hospitable environment for MRSA, the bacteria does not survive longer than 9 days within the midgut. Additionally, MRSA is not amplified within the midgut of the bug as the infection was cleared within 9 days. Due to the weekly feeding behaviours of bed bugs, these results suggest that bed bug transmission of MRSA is highly unlikely.

  6. Evolution of Staphylococcus aureus during human colonization and infection.

    PubMed

    Fitzgerald, J Ross

    2014-01-01

    The diversification of bacterial pathogens during infection is central to their capacity to adapt to different anatomical niches, evade the host immune system, and overcome therapeutic challenges. For example, antimicrobial treatment may fail due to the development of resistance during infection, which is often accompanied by transition to a less virulent state during chronic, persistent infection. In this review, the adaptation of the major human pathogen Staphylococcus aureus to its host environment during infection will be discussed, particularly in the context of new sequencing technologies which have opened a gateway towards understanding of the molecular processes underlying those adaptations. We now have the capacity to address previously intractable questions regarding bacterial diversification during infection which will ultimately lead to enhanced understanding of pathogenesis and the nature of epidemics, and will inform the design of effective therapeutic measures.

  7. Methamphetamine use and methicillin-resistant Staphylococcus aureus skin infections.

    PubMed

    Cohen, Adam L; Shuler, Carrie; McAllister, Sigrid; Fosheim, Gregory E; Brown, Michael G; Abercrombie, Debra; Anderson, Karen; McDougal, Linda K; Drenzek, Cherie; Arnold, Katie; Jernigan, Daniel; Gorwitz, Rachel

    2007-11-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infections and methamphetamine use are emerging public health problems. We conducted a case-control investigation to determine risk factors for MRSA skin and soft tissue infections (SSTIs) in residents of a largely rural southeastern community in the United States. Case-patients were persons >12 years old who had culturable SSTIs; controls had no SSTIs. Of 119 SSTIs identified, 81 (68.1%) were caused by MRSA. Methamphetamine use was reported in 9.9% of case-patients and 1.8% of controls. After we adjusted for age, sex, and race, patients with MRSA SSTIs were more likely than controls to have recently used methamphetamine (odds ratio 5.10, 95% confidence interval 1.55-16.79). MRSA caused most SSTIs in this population. Transmission of MRSA may be occurring among methamphetamine users in this community.

  8. Methamphetamine Use and Methicillin-Resistant Staphylococcus aureus Skin Infections

    PubMed Central

    Shuler, Carrie; McAllister, Sigrid; Fosheim, Gregory E.; Brown, Michael G.; Abercrombie, Debra; Anderson, Karen; McDougal, Linda K.; Drenzek, Cherie; Arnold, Katie; Jernigan, Daniel; Gorwitz, Rachel

    2007-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infections and methamphetamine use are emerging public health problems. We conducted a case–control investigation to determine risk factors for MRSA skin and soft tissue infections (SSTIs) in residents of a largely rural southeastern community in the United States. Case-patients were persons >12 years old who had culturable SSTIs; controls had no SSTIs. Of 119 SSTIs identified, 81 (68.1%) were caused by MRSA. Methamphetamine use was reported in 9.9% of case-patients and 1.8% of controls. After we adjusted for age, sex, and race, patients with MRSA SSTIs were more likely than controls to have recently used methamphetamine (odds ratio 5.10, 95% confidence interval 1.55–16.79). MRSA caused most SSTIs in this population. Transmission of MRSA may be occurring among methamphetamine users in this community. PMID:18217555

  9. [Takotsubo cardiomyopathy in the context of Staphylococcus aureus sepsis].

    PubMed

    Núñez, D; Bermejo, R; Rodríguez-Velasco, A

    2014-03-01

    Takotsubo cardiomyopathy consists of a transient dysfunction of the left ventricle. It is characterised by an impaired left ventricular segmentary contractility, without significant coronary lesions in the coronary angiography. It usually occurs after an episode of physical or emotional stress. We present the case of a 70 year-old woman, who, in the postoperative period of an ankle osteosynthesis, developed a Takotsubo cardiomyopathy in the context of a sepsis caused by Staphylococcus aureus. She presented with acute lung oedema and a clinical picture of low cardiac output. The echocardiogram showed left ventricular medioapical akinesia. Coronary angiography was normal. She was treated with supportive measures with good progress. At 33 days from onset she was able to be discharged from hospital to home with normal systolic function on echocardiography.

  10. Radiosensitization of Staphylococcus aureus by secobarbital sodium and other barbiturates

    SciTech Connect

    Sade, N.; Jacobs, G.P.

    1983-10-01

    The barbiturate hypnotic, secobarbital sodium, at millimolar concentrations, sensitizes Staphylococcus aureus in anoxic buffer-saline suspension (pH 7.0) to the lethal effects of ..gamma.. rays. The maximal response represents 50% of that for oxygenated suspensions without additive. Secobarbital sodium operates within the oxygen effect. It must be present at the time of irradiation for modification of radiation response. This, coupled with its testing in the presence of other additives, points to its involvement in an intracellular reaction with a radiation-induced short-lived chemical species, probably the electron. Preliminary tests show that pentobarbital sodium also operates as an efficient hypoxic radiosensitizer. Lack of sensitization by phenobarbital sodium is attributed to its low lipid solubility.

  11. Innovative approaches to treat Staphylococcus aureus biofilm-related infections.

    PubMed

    Richter, Katharina; Van den Driessche, Freija; Coenye, Tom

    2017-02-28

    Many bacterial infections in humans and animals are caused by bacteria residing in biofilms, complex communities of attached organisms embedded in an extracellular matrix. One of the key properties of microorganisms residing in a biofilm is decreased susceptibility towards antimicrobial agents. This decreased susceptibility, together with conventional mechanisms leading to antimicrobial resistance, makes biofilm-related infections increasingly difficult to treat and alternative antibiofilm strategies are urgently required. In this review, we present three such strategies to combat biofilm-related infections with the important human pathogen Staphylococcus aureus: (i) targeting the bacterial communication system with quorum sensing (QS) inhibitors, (ii) a 'Trojan Horse' strategy to disturb iron metabolism by using gallium-based therapeutics and (iii) the use of 'non-antibiotics' with antibiofilm activity identified through screening of repurposing libraries.

  12. The Role of msa in Staphylococcus aureus Biofilm Formation.

    PubMed

    Sambanthamoorthy, Karthik; Schwartz, Antony; Nagarajan, Vijayaraj; Elasri, Mohamed O

    2008-12-16

    Staphylococcus aureus is an important pathogen that forms biofilms. The global regulator sarA is essential for biofilm formation. Since the modulator of sarA (msa) is required for full expression of sarA and regulates several virulence factors, we examined the capacity of the msa mutant to form biofilm. We found that mutation of msa results in reduced expression of sarA in biofilm and that the msa mutant formed a weak and unstable biofilm. The msa mutant is able to adhere to surfaces and begins to form biofilm but fails to mature indicating that the defect of the msa mutant biofilm is in the accumulation stage but not in primary adhesion. The msa gene plays an important role in biofilm development which is likely due to its role in modulating the expression of sarA. This finding is significant because it identifies a new gene that plays a role in the development of biofilm.

  13. Endogenous, Spontaneous Formation of Beta-Lactamase in Staphylococcus aureus

    PubMed Central

    Sachithanandam, S.; Lowery, D. L.; Saz, A. K.

    1974-01-01

    In a β-lactamase-inducible strain of Staphylococcus aureus, the enzyme appears spontaneously in the absence of added inducer during lag and early log phases of growth and then declines rapidly to low levels. The endogenous inducer responsible for appearance of the enzyme has been isolated and purified and characterized as a peptidoglycan, containing muramic acid, glucosamine, glutamic acid, alanine, lysine, and glycine. The inducing compound could be isolated from the cells only during the lag and early log phases and from no other later periods. The data obtained are consistent with the thesis advanced earlier from this laboratory that β-lactamase serves a cellular function in the producing cell more important and beyond its capability of hydrolyzing certain penicillins to the antibiotically inactive penicilloic acids. PMID:4451348

  14. The Epidemiology of Methicillin-Resistant Staphylococcus aureus in Orthopaedics.

    PubMed

    Atkinson Smith, Mary

    2015-01-01

    In the specialty of orthopaedics, methicillin-resistant Staphylococcus aureus (MRSA) is a major contributor to infections of the soft tissues, surgical sites, and joints, in addition to increasing disability, mortality, and healthcare costs. Inappropriate prescribing and misuse of antibiotics have led to bacterial resistance and the rapid emergence of MRSA. It is imperative for healthcare providers and facilities to improve quality, promote safety, and decrease costs related to MRSA infections. The healthcare profession and society as a whole play an important role in minimizing the transmission of pathogens, reducing the incidence of MRSA infections, and decreasing the development of future antibiotic resistant pathogens. This article discusses the epidemiology of MRSA and describes evidence-based guidelines pertaining to the prevention, minimization, and treatment of MRSA-related infections. Specific application to orthopaedics are discussed in the context of patient risk factors, perioperative and postoperative prophylaxis, and current trends regarding education and reporting strategies.

  15. Atropisomeric dihydroanthracenones as inhibitors of multiresistant Staphylococcus aureus.

    PubMed

    Bara, Robert; Zerfass, Ilka; Aly, Amal H; Goldbach-Gecke, Heike; Raghavan, Vijay; Sass, Peter; Mándi, Attila; Wray, Victor; Polavarapu, Prasad L; Pretsch, Alexander; Lin, WenHan; Kurtán, Tibor; Debbab, Abdessamad; Brötz-Oesterhelt, Heike; Proksch, Peter

    2013-04-25

    Two bisdihydroanthracenone atropodiastereomeric pairs, including homodimeric flavomannin A (1) and the previously unreported flavomannin B (2), two new unsymmetrical dimers (3 and 4), and two new mixed dihydroanthracenone/anthraquinone dimers (5 and 6) were isolated from Talaromyces wortmannii , an endophyte of Aloe vera . The structures of 2-6 were elucidated by extensive NMR and mass spectrometric analyses. The axial chirality of the biaryls was determined using TDDFT ECD and VCD calculations, the combination of which however did not allow the assignment of the central chirality elements of 1. The compounds exhibited antibacterial activity against Staphylococcus aureus , including (multi)drug-resistant clinical isolates. Reporter gene analyses indicated induction of the SOS response for some of the derivatives, suggesting interference with DNA structure or metabolism. Fluorescence microscopy demonstrated defective segregation of the bacterial chromosome and DNA degradation. Notably, the compounds showed no cytotoxic activity, encouraging their further evaluation as potential starting points for antibacterial drug development.

  16. Phenazine antibiotic inspired discovery of potent bromophenazine antibacterial agents against Staphylococcus aureus and Staphylococcus epidermidis.

    PubMed

    Borrero, Nicholas V; Bai, Fang; Perez, Cristian; Duong, Benjamin Q; Rocca, James R; Jin, Shouguang; Huigens, Robert W

    2014-02-14

    Nearly all clinically used antibiotics have been (1) discovered from microorganisms (2) using phenotype screens to identify inhibitors of bacterial growth. The effectiveness of these antibiotics is attributed to their endogenous roles as bacterial warfare agents against competing microorganisms. Unfortunately, every class of clinically used antibiotic has been met with drug resistant bacteria. In fact, the emergence of resistant bacterial infections coupled to the dismal pipeline of new antibacterial agents has resulted in a global health care crisis. There is an urgent need for innovative antibacterial strategies and treatment options to effectively combat drug resistant bacterial pathogens. Here, we describe the implementation of a Pseudomonas competition strategy, using redox-active phenazines, to identify novel antibacterial leads against Staphylococcus aureus and Staphylococcus epidermidis. In this report, we describe the chemical synthesis and evaluation of a diverse 27-membered phenazine library. Using this microbial warfare inspired approach, we have identified several bromophenazines with potent antibacterial activities against S. aureus and S. epidermidis. The most potent bromophenazine analogue from this focused library demonstrated a minimum inhibitory concentration (MIC) of 0.78-1.56 μM, or 0.31-0.62 μg mL(-1), against S. aureus and S. epidermidis and proved to be 32- to 64-fold more potent than the phenazine antibiotic pyocyanin in head-to-head MIC experiments. In addition to the discovery of potent antibacterial agents against S. aureus and S. epidermidis, we also report a detailed structure-activity relationship for this class of bromophenazine small molecules.

  17. Electron Microscopy of Staphylococcus aureus Cell Wall Lysis

    PubMed Central

    Virgilio, R.; González, C.; Muñoz, Nubia; Mendoza, Silvia

    1966-01-01

    Virgilio, Rafael (Escuela de Química y Farmacia, Universidad de Chile, Santiago, Chile), C. González, Nubia Muñoz, and Silvia Mendoza. Electron microscopy of Staphylococcus aureus cell wall lysis. J. Bacteriol. 91:2018–2024. 1966.—A crude suspension of Staphylococcus aureus cell walls (strain Cowan III) in buffer solution was shown by electron microscopy to lyse slightly after 16 hr, probably owing to the action of autolysin. The lysis was considerably faster and more intense after the addition of lysozyme. A remarkable reduction in thickness and rigidity of the cell walls, together with the appearance of many irregular protrusions in their outlines, was observed after 2 hr; after 16 hr, there remained only a few recognizable cell wall fragments but many residual particulate remnants. When autolysin was previously inactivated by trypsin, there was a complete inhibition of the lytic action of lysozyme; on the other hand, when autolysin was inactivated by heat and lysozyme was added, a distinct decrease in the thickness of the cell walls was observed, but there was no destruction of the walls. The lytic action of lysozyme, after treatment with hot 5% trichloroacetic acid, gave rise to a marked dissolution of the structure of the cell walls, which became lost against the background, without, however, showing ostensible alteration of wall outlines. From a morphological point of view, the lytic action of autolysin plus lysozyme was quite different from that of trichloroacetic acid plus lysozyme, as shown by electron micrographs, but in both cases it was very intense. This would suggest different mechanisms of action for these agents. Images PMID:5939482

  18. Electron microscopy of Staphylococcus aureus cell wall lysis.

    PubMed

    Virgilio, R; González, C; Muñoz, N; Mendoza, S

    1966-05-01

    Virgilio, Rafael (Escuela de Química y Farmacia, Universidad de Chile, Santiago, Chile), C. González, Nubia Muñoz, and Silvia Mendoza. Electron microscopy of Staphylococcus aureus cell wall lysis. J. Bacteriol. 91:2018-2024. 1966.-A crude suspension of Staphylococcus aureus cell walls (strain Cowan III) in buffer solution was shown by electron microscopy to lyse slightly after 16 hr, probably owing to the action of autolysin. The lysis was considerably faster and more intense after the addition of lysozyme. A remarkable reduction in thickness and rigidity of the cell walls, together with the appearance of many irregular protrusions in their outlines, was observed after 2 hr; after 16 hr, there remained only a few recognizable cell wall fragments but many residual particulate remnants. When autolysin was previously inactivated by trypsin, there was a complete inhibition of the lytic action of lysozyme; on the other hand, when autolysin was inactivated by heat and lysozyme was added, a distinct decrease in the thickness of the cell walls was observed, but there was no destruction of the walls. The lytic action of lysozyme, after treatment with hot 5% trichloroacetic acid, gave rise to a marked dissolution of the structure of the cell walls, which became lost against the background, without, however, showing ostensible alteration of wall outlines. From a morphological point of view, the lytic action of autolysin plus lysozyme was quite different from that of trichloroacetic acid plus lysozyme, as shown by electron micrographs, but in both cases it was very intense. This would suggest different mechanisms of action for these agents.

  19. [Severe infection by methicillin sensitive Staphylococcus aureus producing Panton-Valentine leukocidin: reports of two cases].

    PubMed

    Brizuela, Martín; Pérez, Guadalupe; Ruvinsky, Silvina; Sarkis, Claudia; Romero, Romina; Mastroianni, Alejandra; Casimir, Lidia; Venuta, María E; Gómez Bonduele, Verónica; Bologna, Rosa

    2016-08-01

    Staphylococcus aureus is a major etiologic agent of infections in children from the community and the hospital setting. The severity of these conditions is associated with virulence factors, including the Panton-Valentine leukocidin. Both methicillin resistant and sensitive Staphylococcus aureus produce this leukocidin although with varying frequency. We present two children with severe infection by sensitive Staphylococcus aureus producer of Panton-Valentine leukocidin with musculoskeletal and endovascular complications. It is essential the suspected diagnosis, appropriate antibiotic treatment and early surgical management to improve the approach of these infections. Epidemiological surveillance should be mantained to detect the frequency of infections caused by these bacteria.

  20. Australian Staphylococcus aureus Sepsis Outcome Programme annual report, 2013.

    PubMed

    Coombs, Geoffrey W; Nimmo, Graeme R; Daly, Denise A; Le, Tam T; Pearson, Julie C; Tan, Hui-Leen; Robinson, James O; Collignon, Peter J; McLaws, Mary-Louise; Turnidge, John D

    2014-12-31

    From 1 January to 31 December 2013, around Australia 26 institutions around Australia participated in the Australian Staphylococcal Sepsis Outcome Programme (ASSOP). The aim of ASSOP 2013 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that are antimicrobial resistant, (with particular emphasis on susceptibility to methicillin) and to characterise the molecular epidemiology of the isolates. Overall 19.1% of the 2,010 SAB episodes were methicillin resistant, which is significantly higher than that reported in most European countries. Although the SAB 30-day all cause mortality appears to be decreasing in Australia, methicillin-resistant SAB associated mortality remains high (20.1%) and was significantly higher than methicillin-sensitive SAB associated mortality (13%) (P< 0.0001). With the exception of the ß-lactams and erythromycin, antimicrobial resistance in methicillin sensitive S. aureus remains rare. However, in addition to the ß-lactams, approximately 50% of methicillin-resistant S. aureus (MRSA) were resistant to erythromycin and ciprofloxacin and approximately 20% were resistant to co-trimoxazole, tetracycline and gentamicin. Linezolid, daptomycin and teicoplanin resistance was detected in a small number of S. aureus isolates. Resistance to vancomycin was not detected. Resistance was largely attributable to 2 healthcare associated MRSA clones; ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA). ST22-IV [2B] (EMRSA-15) has now become the predominant healthcare associated clone in Australia. Approximately 60% of methicillin-resistant SAB were due to community associated clones. Although polyclonal, almost 50% of community associated clones were characterised as ST93-IV [2B] (Queensland CA-MRSA) and ST1-IV [2B] (WA1). CA-MRSA, in particular the ST45-V [5C2&5] (WA84) clone, has acquired multiple antimicrobial resistance determinants including ciprofloxacin, erythromycin, clindamycin, gentamicin and

  1. Carriage, Clinical Microbiology and Transmission of Staphylococcus aureus.

    PubMed

    Aryee, Anna; Edgeworth, Jonathan D

    2016-04-21

    Staphylococcus aureus is one of the most important bacterial pathogens in clinical practice and a major diagnostic focus for the routine microbiology laboratory. It is carried as a harmless commensal in up to two-thirds of the population at any one time predominantly not only in the anterior nares, but also in multiple other sites such as the groin, axilla, throat, perineum, vagina and rectum. It colonizes skin breach sites, such as ulcers and wounds, and causes superficial and deep skin and soft tissue infections and life-threatening deep seated infections particularly endocarditis and osteomyelitis. S. aureus is constantly evolving through mutation and uptake of mobile genetic elements that confer increasing resistance and virulence. Since the 1960s, hospitals have had to contend with emergence of methicillin-resistant S. aureus (MRSA) strains that spread better in hospitals than methicillin-susceptible S. aureus (MSSA) and are harder to treat. Since the 1980s, distinct community MRSA strains have also emerged that cause severe skin and respiratory infections. Conventional identification of MSSA and MRSA in the microbiology laboratory involves microscopy, culture and biochemical analysis that for most samples is straightforward but slow, taking at least 48 h. This delay has significant consequences for individual patient care and public health, through inadequate or excessive empiric antibiotic use, and failure to implement appropriate infection control measures for MRSA-colonized patients during those first 48 h. This unmet need has driven development of rapid molecular diagnostics that either complement or replace conventional culture techniques in the laboratory, or can be placed in the clinical environment as point-of-care (POC) devices. These new technologies provide results to clinicians anything from within an hour to 24 h, depending on sample and clinical setting, and should transform management of patients with S. aureus and other bacterial diseases

  2. Clonality and Antimicrobial Susceptibility of Staphylococcus aureus and Methicillin-Resistant S. aureus Isolates from Food Animals and Other Animals

    PubMed Central

    Chow, Kin-Hung; Lai, Eileen L.; Law, Pierra Y. T.; Chan, Pui-Ying; Ho, Alex Y. M.; Ng, Tak-Keung; Yam, Wing-Cheong

    2012-01-01

    Out of 3,081 animals studied, 24.9% of pigs, 4.7% of chickens, 6.3% of dogs, 10.5% of cats, and 7.1% of rodents were Staphylococcus aureus positive. Prevalence of methicillin-resistant S. aureus (MRSA) was high in pigs (animals, 21.3%; batches, 46.5%), with all MRSA isolates and most methicillin-sensitive S. aureus isolates belonging to clonal complex 9 (CC9) and being multidrug resistant. The predominant S. aureus CCs among dog and cat isolates were similar. Among rodent isolates, CC398 predominated, with spa t034 the most frequent spa type detected. PMID:22895044

  3. Clonality and antimicrobial susceptibility of Staphylococcus aureus and methicillin-resistant S. aureus isolates from food animals and other animals.

    PubMed

    Ho, Pak-Leung; Chow, Kin-Hung; Lai, Eileen L; Law, Pierra Y T; Chan, Pui-Ying; Ho, Alex Y M; Ng, Tak-Keung; Yam, Wing-Cheong

    2012-11-01

    Out of 3,081 animals studied, 24.9% of pigs, 4.7% of chickens, 6.3% of dogs, 10.5% of cats, and 7.1% of rodents were Staphylococcus aureus positive. Prevalence of methicillin-resistant S. aureus (MRSA) was high in pigs (animals, 21.3%; batches, 46.5%), with all MRSA isolates and most methicillin-sensitive S. aureus isolates belonging to clonal complex 9 (CC9) and being multidrug resistant. The predominant S. aureus CCs among dog and cat isolates were similar. Among rodent isolates, CC398 predominated, with spa t034 the most frequent spa type detected.

  4. Sources of intramammary infections from Staphylococcus aureus in dairy heifers at first parturition.

    PubMed

    Roberson, J R; Fox, L K; Hancock, D D; Gay, J M; Besser, T E

    1998-03-01

    The study objective was to identify probable sources and modes of transmission of 91 Staphylococcus aureus isolates obtained from the colostrum of 76 heifers at parturition. Sources cultured were milk (including colostrum), heifer body sites (teats, muzzle, rectum, vagina, and lacteal secretions), and environmental sites (bedding, insects, housing, water, feedstuffs, humans, nonbovine animals, air, and equipment). Staphylococcus aureus isolates were characterized by 63 phenotypic traits. A similarity coefficient was calculated by herd to identify the S. aureus that most closely resembled the S. aureus obtained from heifer colostrum. Staphylococcus aureus from a heifer's colostrum was compared with all preexisting S. aureus isolates from that heifer's herd. Isolates that were > or = 90% similar were considered to be identical. Because 30 (of the 91) S. aureus isolates from heifer colostrum were collected prior to environmental sampling, only 61 S. aureus isolates from heifer colostrum were available for comparison among all three sources. Possible sources of S. aureus from heifer colostrum at parturition were milk (70%, 43 of 61 isolates), heifer body sites (39%, 24 of 61), environmental sites (28%, 17 of 61), or no identified source (16%, 10 of 61). Three heifers with intramammary infection (IMI) from S. aureus at parturition had the same S. aureus on their teats prior to parturition. Milk was the only source identified for 41% (25 of 61) of isolates from heifer colostrum. Isolates from heifer body sites were the only source identified for 5% (3 of 61) of heifer colostrum isolates. Staphylococcus aureus from the environment was never the sole possible source for S. aureus from heifer colostrum. Data suggest that the major sources of S. aureus IMI in heifers at parturition are milk and heifer body sites. Contact among heifers may be an important mode of transmission of S. aureus leading to IMI in heifers at parturition.

  5. Oxidative and nitrosative stress in Staphylococcus aureus biofilm.

    PubMed

    Arce Miranda, Julio E; Sotomayor, Claudia E; Albesa, Inés; Paraje, María G

    2011-02-01

    Diverse chemical and physical agents can alter cellular functions associated with oxidative metabolism, thus stimulating the production of reactive oxygen species (ROS) and reactive nitrogen intermediates (RNI) in planktonic bacterial physiology. However, more research is necessary to determine the precise role of cellular stress in biofilm. The present study was designed to address the issues of Staphylococcus aureus biofilm formation with respect to the generation of oxidative and nitrosative stress. We studied three pathogenic S. aureus clinical strains and an ATCC strain exposed to a different range of culture conditions (time, temperature, pH, reduction and atmospheric conditions) using quantitative methods of biofilm detection. We observed that cellular stress could be produced inside biofilms, thereby affecting their growth, resulting in an increase of ROS and RNI production, and a decrease of the extracellular matrix under unfavorable conditions. These radical oxidizers could then accumulate in an extracellular medium and thus affect the matrix. These results contribute to a better understanding of the processes that enable adherent biofilms to grow on inert surfaces and lead to an improved knowledge of ROS and RNI regulation, which may help to clarify the relevance of biofilm formation in medical devices.

  6. Cooperation, Quorum Sensing, and Evolution of Virulence in Staphylococcus aureus

    PubMed Central

    Pollitt, Eric J. G.; West, Stuart A.; Crusz, Shanika A.; Burton-Chellew, Maxwell N.

    2014-01-01

    The virulence and fitness in vivo of the major human pathogen Staphylococcus aureus are associated with a cell-to-cell signaling mechanism known as quorum sensing (QS). QS coordinates the production of virulence factors via the production and sensing of autoinducing peptide (AIP) signal molecules by the agr locus. Here we show, in a wax moth larva virulence model, that (i) QS in S. aureus is a cooperative social trait that provides a benefit to the local population of cells, (ii) agr mutants, which do not produce or respond to QS signal, are able to exploit the benefits provided by the QS of others (“cheat”), allowing them to increase in frequency when in mixed populations with cooperators, (iii) these social interactions between cells determine virulence, with the host mortality rate being negatively correlated to the percentage of agr mutants (“cheats”) in a population, and (iv) a higher within-host relatedness (lower strain diversity) selects for QS and hence higher virulence. Our results provide an explanation for why agr mutants show reduced virulence in animal models but can be isolated from infections of humans. More generally, by providing the first evidence that QS is a cooperative social behavior in a Gram-positive bacterium, our results suggest convergent, and potentially widespread, evolution for signaling to coordinate cooperation in bacteria. PMID:24343650

  7. Autophagy Mediates Tolerance to Staphylococcus aureus Alpha-Toxin

    PubMed Central

    Maurer, Katie; Reyes-Robles, Tamara; Alonzo, Francis; Durbin, Joan; Torres, Victor J.; Cadwell, Ken

    2015-01-01

    SUMMARY Resistance and tolerance are two defense strategies employed by the host against microbial threats. Autophagy-mediated degradation of bacteria has been extensively described as a major resistance mechanism. Here we find that the dominant function of autophagy proteins during infections with the epidemic community-associated methicillin-resistant Staphylococcus aureus USA 300 is to mediate tolerance rather than resistance. Atg16L1 hypomorphic mice (Atg16L1HM), which have reduced autophagy, were highly susceptible to lethality in both sepsis and pneumonia models of USA300 infection. Autophagy confers protection by limiting the damage caused by α-toxin, particularly to endothelial cells. Remarkably, Atg16L1HM mice display enhanced survival rather than susceptibility upon infection with α-toxin deficient S. aureus. These results identify an essential role for autophagy in tolerance to Staphylococcal disease and highlight how a single virulence factor encoded by a pathogen can determine whether a given host factor promotes tolerance or resistance. PMID:25816775

  8. Expression and crystallization of DsbA from Staphylococcus aureus

    SciTech Connect

    Heras, B. Kurz, M.; Jarrott, R.; Byriel, K. A.; Jones, A.; Thöny-Meyer, L.; Martin, J. L.

    2007-11-01

    Free-interface diffusion crystallization chips were used to identify crystallization conditions for S. aureus DsbA, representing the first Gram-positive DsbA to be crystallized. Native and selenomethionine-derivative crystals diffracted to 2.1 and 2.4 Å resolution, respectively. Bacterial Dsb proteins catalyse the in vivo formation of disulfide bonds, a critical step in the stability and activity of many proteins. Most studies on Dsb proteins have focused on Gram-negative bacteria and thus the process of oxidative folding in Gram-positive bacteria is poorly understood. To help elucidate this process in Gram-positive bacteria, DsbA from Staphylococcus aureus (SaDsbA) has been focused on. Here, the expression, purification, crystallization and preliminary diffraction analysis of SaDsbA are reported. SaDsbA crystals diffract to a resolution limit of 2.1 Å and belong to the hexagonal space group P6{sub 5} or P6{sub 1}, with unit-cell parameters a = b = 72.1, c = 92.1 Å and one molecule in the asymmetric unit (64% solvent content)

  9. Excreted Cytoplasmic Proteins Contribute to Pathogenicity in Staphylococcus aureus

    PubMed Central

    Ebner, Patrick; Rinker, Janina; Nguyen, Minh Thu; Popella, Peter; Nega, Mulugeta; Luqman, Arif; Schittek, Birgit; Di Marco, Moreno; Stevanovic, Stefan

    2016-01-01

    Excretion of cytoplasmic proteins in pro- and eukaryotes, also referred to as “nonclassical protein export,” is a well-known phenomenon. However, comparatively little is known about the role of the excreted proteins in relation to pathogenicity. Here, the impact of two excreted glycolytic enzymes, aldolase (FbaA) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), on pathogenicity was investigated in Staphylococcus aureus. Both enzymes bound to certain host matrix proteins and enhanced adherence of the bacterial cells to host cells but caused a decrease in host cell invasion. FbaA and GAPDH also bound to the cell surfaces of staphylococcal cells by interaction with the major autolysin, Atl, that is involved in host cell internalization. Surprisingly, FbaA showed high cytotoxicity to both MonoMac 6 (MM6) and HaCaT cells, while GAPDH was cytotoxic only for MM6 cells. Finally, the contribution of external FbaA and GAPDH to S. aureus pathogenicity was confirmed in an insect infection model. PMID:27001537

  10. Multidrug Efflux Pumps in Staphylococcus aureus: an Update.

    PubMed

    Costa, Sofia Santos; Viveiros, Miguel; Amaral, Leonard; Couto, Isabel

    2013-01-01

    The emergence of infections caused by multi- or pan-resistant bacteria in the hospital or in the community settings is an increasing health concern. Albeit there is no single resistance mechanism behind multiresistance, multidrug efflux pumps, proteins that cells use to detoxify from noxious compounds, seem to play a key role in the emergence of these multidrug resistant (MDR) bacteria. During the last decades, experimental data has established their contribution to low level resistance to antimicrobials in bacteria and their potential role in the appearance of MDR phenotypes, by the extrusion of multiple, unrelated compounds. Recent studies suggest that efflux pumps may be used by the cell as a first-line defense mechanism, avoiding the drug to reach lethal concentrations, until a stable, more efficient alteration occurs, that allows survival in the presence of that agent. In this paper we review the current knowledge on MDR efflux pumps and their intricate regulatory network in Staphylococcus aureus, a major pathogen, responsible from mild to life-threatening infections. Particular emphasis will be given to the potential role that S. aureus MDR efflux pumps, either chromosomal or plasmid-encoded, have on resistance towards different antimicrobial agents and on the selection of drug - resistant strains. We will also discuss the many questions that still remain on the role of each specific efflux pump and the need to establish appropriate methodological approaches to address all these questions.

  11. The antimicrobial effects of cranberry against Staphylococcus aureus.

    PubMed

    Lian, Poh Yng; Maseko, T; Rhee, M; Ng, K

    2012-04-01

    The antimicrobial effects of the American cranberry (Vaccinium macrocarpon) on a major food-borne pathogen, Staphylococcus aureus, were investigated using commercially obtained Lakewood® organic cranberry juice and Ocean Spray® cranberry juice cocktail and four other berry fruit extracts (acai berry, strawberry, raspberry, and blueberry). The results showed that cranberry is a potent antimicrobial against S. aureus and the most potent among the berries studied. The order of percentage inhibition of bacterial growth at the same concentration of phenolic materials as gallic acid equivalents was Lakewood cranberry juice > Ocean Spray cranberry juice ≫ blueberry > acai berry ≫ raspberry ≫ strawberry. The antimicrobial effect was not due to the acidity of the berries as NaOH-neutralized samples were almost as effective in terms of percentage inhibition of viable cell growth. Solid-phase extraction of cranberry juice using C18 solid phase showed that the antimicrobial effects reside exclusively with the C18-bound materials.

  12. Antimicrobial activity of essential oils against Staphylococcus aureus biofilms.

    PubMed

    Vázquez-Sánchez, Daniel; Cabo, Marta L; Rodríguez-Herrera, Juan J

    2015-12-01

    The present study was aimed to evaluate the potential of essential oils to remove the foodborne pathogen Staphylococcus aureus from food-processing facilities. The effectiveness of 19 essential oils against planktonic cells of S. aureus was firstly assessed by minimal inhibitory concentration. Planktonic cells showed a wide variability in resistance to essential oils, with thyme oil as the most effective, followed by lemongrass oil and then vetiver oil. The eight essential oils most effective against planktonic cells were subsequently tested against 48-h-old biofilms formed on stainless steel. All essential oils reduced significantly (p < 0.01) the number of viable biofilm cells, but none of them could remove biofilms completely. Thyme and patchouli oils were the most effective, but high concentrations were needed to achieve logarithmic reductions over 4 log CFU/cm(2) after 30 min exposure. Alternatively, the use of sub-lethal doses of thyme oil allowed to slow down biofilm formation and to enhance the efficiency of thyme oil and benzalkonium chloride against biofilms. However, some cellular adaptation to thyme oil was detected. Therefore, essential oil-based treatments should be based on the rotation and combination of different essential oils or with other biocides to prevent the emergence of antimicrobial-resistant strains. © The Author(s) 2014.

  13. Characterization of transcription within sdr region of Staphylococcus aureus.

    PubMed

    Sitkiewicz, Izabela; Babiak, Ireneusz; Hryniewicz, Waleria

    2011-02-01

    Staphylococcus aureus is an opportunistic pathogen responsible for various infections in humans and animals. It causes localized and systemic infections, such as abscesses, impetigo, cellulitis, sepsis, endocarditis, bone infections, and meningitis. S. aureus virulence factors responsible for the initial contact with host cells (MSCRAMMs-microbial surface components recognizing adhesive matrix molecules) include three Sdr proteins. The presence of particular sdr genes is correlated with putative tissue specificity. The transcriptional organization of the sdr region remains unclear. We tested expression of the sdrC, sdrD, or sdrE genes in various in vitro conditions, as well as after contact with human blood. In this work, we present data suggesting a separation of the sdr region into three transcriptional units, based on their differential reactions to the environment. Differential reaction of the sdrD transcript to environmental conditions and blood suggests dissimilar functions of the sdr genes. SdrE has been previously proposed to play role in bone infections, whilst our results can indicate that sdrD plays a role in the interactions between the pathogen and human immune system, serum or specifically reacts to nutrients/other factors present in human blood.

  14. Converting a Staphylococcus aureus toxin into effective cyclic pseudopeptide antibiotics.

    PubMed

    Solecki, Olivia; Mosbah, Amor; Baudy Floc'h, Michèle; Felden, Brice

    2015-03-19

    Staphylococcus aureus produces peptide toxins that it uses to respond to environmental cues. We previously characterized PepA1, a peptide toxin from S. aureus, that induces lytic cell death of both bacterial and host cells. That led us to suggest that PepA1 has an antibacterial activity. Here, we demonstrate that exogenously provided PepA1 has activity against both Gram-positive and Gram-negative bacteria. We also see that PepA1 is significantly hemolytic, thus limiting its use as an antibacterial agent. To overcome these limitations, we converted PepA1 into nonhemolytic derivatives. Our most promising derivative is a cyclic heptapseudopeptide with inconsequential toxicity to human cells, enhanced stability in human sera, and sharp antibacterial activity. Mechanistically, linear and helical PepA1 derivatives form pores at the bacterial and erythrocyte surfaces, while the cyclic peptide induces bacterial envelope reorganization, with insignificant action on the erythrocytes. Our work demonstrates that bacterial toxins might be an attractive starting point for antibacterial drug development.

  15. Autophagy mediates tolerance to Staphylococcus aureus alpha-toxin.

    PubMed

    Maurer, Katie; Reyes-Robles, Tamara; Alonzo, Francis; Durbin, Joan; Torres, Victor J; Cadwell, Ken

    2015-04-08

    Resistance and tolerance are two defense strategies employed by the host against microbial threats. Autophagy-mediated degradation of bacteria has been extensively described as a major resistance mechanism. Here we find that the dominant function of autophagy proteins during infections with the epidemic community-associated methicillin-resistant Staphylococcus aureus USA300 is to mediate tolerance rather than resistance. Atg16L1 hypomorphic mice (Atg16L1(HM)), which have reduced autophagy, were highly susceptible to lethality in both sepsis and pneumonia models of USA300 infection. Autophagy confers protection by limiting the damage caused by α-toxin, particularly to endothelial cells. Remarkably, Atg16L1(HM) mice display enhanced survival rather than susceptibility upon infection with α-toxin-deficient S. aureus. These results identify an essential role for autophagy in tolerance to Staphylococcal disease and highlight how a single virulence factor encoded by a pathogen can determine whether a given host factor promotes tolerance or resistance. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Multidrug Efflux Pumps in Staphylococcus aureus: an Update

    PubMed Central

    Costa, Sofia Santos; Viveiros, Miguel; Amaral, Leonard; Couto, Isabel

    2013-01-01

    The emergence of infections caused by multi- or pan-resistant bacteria in the hospital or in the community settings is an increasing health concern. Albeit there is no single resistance mechanism behind multiresistance, multidrug efflux pumps, proteins that cells use to detoxify from noxious compounds, seem to play a key role in the emergence of these multidrug resistant (MDR) bacteria. During the last decades, experimental data has established their contribution to low level resistance to antimicrobials in bacteria and their potential role in the appearance of MDR phenotypes, by the extrusion of multiple, unrelated compounds. Recent studies suggest that efflux pumps may be used by the cell as a first-line defense mechanism, avoiding the drug to reach lethal concentrations, until a stable, more efficient alteration occurs, that allows survival in the presence of that agent. In this paper we review the current knowledge on MDR efflux pumps and their intricate regulatory network in Staphylococcus aureus, a major pathogen, responsible from mild to life-threatening infections. Particular emphasis will be given to the potential role that S. aureus MDR efflux pumps, either chromosomal or plasmid-encoded, have on resistance towards different antimicrobial agents and on the selection of drug - resistant strains. We will also discuss the many questions that still remain on the role of each specific efflux pump and the need to establish appropriate methodological approaches to address all these questions. PMID:23569469

  17. Staphylococcus aureus infections: transmission within households and the community.

    PubMed

    Knox, Justin; Uhlemann, Anne-Catrin; Lowy, Franklin D

    2015-07-01

    Staphylococcus aureus, both methicillin susceptible and resistant, are now major community-based pathogens worldwide. The basis for this is multifactorial and includes the emergence of epidemic clones with enhanced virulence, antibiotic resistance, colonization potential, or transmissibility. Household reservoirs of these unique strains are crucial to their success as community-based pathogens. Staphylococci become resident in households, either as colonizers or environmental contaminants, increasing the risk for recurrent infections. Interactions of household members with others in different households or at community sites, including schools and daycare facilities, have a critical role in the ability of these strains to become endemic. Colonization density at these sites appears to have an important role in facilitating transmission. The integration of research tools, including whole-genome sequencing (WGS), mathematical modeling, and social network analysis, has provided additional insight into the transmission dynamics of these strains. Thus far, interventions designed to reduce recurrent infections among household members have had limited success, likely due to the multiplicity of potential sources for recolonization. The development of better strategies to reduce the number of household-based infections will depend on greater insight into the different factors that contribute to the success of these uniquely successful epidemic clones of S. aureus.

  18. Cooperation, quorum sensing, and evolution of virulence in Staphylococcus aureus.

    PubMed

    Pollitt, Eric J G; West, Stuart A; Crusz, Shanika A; Burton-Chellew, Maxwell N; Diggle, Stephen P

    2014-03-01

    The virulence and fitness in vivo of the major human pathogen Staphylococcus aureus are associated with a cell-to-cell signaling mechanism known as quorum sensing (QS). QS coordinates the production of virulence factors via the production and sensing of autoinducing peptide (AIP) signal molecules by the agr locus. Here we show, in a wax moth larva virulence model, that (i) QS in S. aureus is a cooperative social trait that provides a benefit to the local population of cells, (ii) agr mutants, which do not produce or respond to QS signal, are able to exploit the benefits provided by the QS of others ("cheat"), allowing them to increase in frequency when in mixed populations with cooperators, (iii) these social interactions between cells determine virulence, with the host mortality rate being negatively correlated to the percentage of agr mutants ("cheats") in a population, and (iv) a higher within-host relatedness (lower strain diversity) selects for QS and hence higher virulence. Our results provide an explanation for why agr mutants show reduced virulence in animal models but can be isolated from infections of humans. More generally, by providing the first evidence that QS is a cooperative social behavior in a Gram-positive bacterium, our results suggest convergent, and potentially widespread, evolution for signaling to coordinate cooperation in bacteria.

  19. Susceptibility of Staphylococcus aureus biofilms to reactive discharge gases

    PubMed Central

    Traba, Christian; Liang, Jun F.

    2011-01-01

    Formation of bacterial biofilms at solid-liquid interfaces creates numerous problems in both industrial and biomedical sciences. In this study, the susceptibility of Staphylococcus aureus biofilms to discharge gas generated from plasma was tested. It was found that despite distinct chemical/physical properties, discharge gases from oxygen, nitrogen, and argon demonstrated very potent and almost the same anti-biofilm activity. The bacterial cells in S. aureus biofilms were killed (>99.9%) by discharge gas within minutes of exposure. Under optimal experimental conditions, no bacteria and biofilm re-growth from discharge gas treated biofilms was found. Further studies revealed that the anti-biofilm activity of the discharge gas occurred by two distinct mechanisms: 1) killing bacteria in biofilms by causing severe cell membrane damage, and 2) damaging the extracellular polymeric matrix in the architecture of the biofilm to release biofilm from the surface of the solid substratum . Information gathered from this study provides an insight into the anti-biofilm mechanisms of plasma and confirms the applications of discharge gas in the treatment of biofilms and biofilm related bacterial infections. PMID:21774615

  20. Glucose Augments Killing Efficiency of Daptomycin Challenged Staphylococcus aureus Persisters

    PubMed Central

    Prax, Marcel; Mechler, Lukas; Weidenmaier, Christopher; Bertram, Ralph

    2016-01-01

    Treatment of Staphylococcus aureus in stationary growth phase with high doses of the antibiotic daptomycin (DAP) eradicates the vast majority of the culture and leaves persister cells behind. Despite resting in a drug-tolerant and dormant state, persister cells exhibit metabolic activity which might be exploited for their elimination. We here report that the addition of glucose to S. aureus persisters treated with DAP increased killing by up to five-fold within one hour. This glucose-DAP effect also occurred with strains less sensitive to the drug. The underlying mechanism is independent of the proton motive force and was not observed with non-metabolizable 2-deoxy-glucose. Our results are consistent with two hypotheses on the glucose-DAP interplay. The first is based upon glucose-induced carbohydrate transport proteins that may influence DAP and the second suggests that glucose may trigger the release or activity of cell-lytic proteins to augment DAP’s mode of action. PMID:26960193

  1. Staphylococcus aureus bacteraemia: 400 episodes in St Thomas's Hospital.

    PubMed

    Gransden, W R; Eykyn, S J; Phillips, I

    1984-01-28

    Four hundred episodes of Staphylococcus aureus bacteraemia occurred in St Thomas's Hospital from 1969 to 1983, accounting for 17.5% of all episodes of bacteraemia. The mortality was 24%, half attributable to underlying disease, and was highest in patients over 50. Almost 60% of the bacteraemias were acquired in hospital, and the source of the organism was generally obvious, with vascular access sites the most common (37%). Bone and joint infections accounted for 11.5% of episodes and endocarditis for 7%. Most staphylococci were resistant to penicillin only; three isolates were resistant to methicillin and five to fusidic acid. Microbiologists seldom influenced directly the choice of initial antibiotic treatment (though this usually conformed to the hospital's antibiotic prescribing policy) but had considerable influence over definitive treatment, usually cloxacillin or flucloxacillin alone or in combination with fusidic acid. S aureus bacteraemia is easy to identify and treat, though underlying disease may influence the outcome. Efforts should be made to prevent the largely iatrogenic disease.

  2. Recombination-Mediated Host Adaptation by Avian Staphylococcus aureus

    PubMed Central

    Murray, Susan; Pascoe, Ben; Méric, Guillaume; Mageiros, Leonardos; Yahara, Koji; Hitchings, Matthew D.; Friedmann, Yasmin; Wilkinson, Thomas S.; Gormley, Fraser J.; Mack, Dietrich; Bray, James E.; Lamble, Sarah; Bowden, Rory; Jolley, Keith A.; Maiden, Martin C.J.; Wendlandt, Sarah; Schwarz, Stefan; Corander, Jukka; Fitzgerald, J. Ross

    2017-01-01

    Staphylococcus aureus are globally disseminated among farmed chickens causing skeletal muscle infections, dermatitis, and septicaemia. The emergence of poultry-associated lineages has involved zoonotic transmission from humans to chickens but questions remain about the specific adaptations that promote proliferation of chicken pathogens. We characterized genetic variation in a population of genome-sequenced S. aureus isolates of poultry and human origin. Genealogical analysis identified a dominant poultry-associated sequence cluster within the CC5 clonal complex. Poultry and human CC5 isolates were significantly distinct from each other and more recombination events were detected in the poultry isolates. We identified 44 recombination events in 33 genes along the branch extending to the poultry-specific CC5 cluster, and 47 genes were found more often in CC5 poultry isolates compared with those from humans. Many of these gene sequences were common in chicken isolates from other clonal complexes suggesting horizontal gene transfer among poultry associated lineages. Consistent with functional predictions for putative poultry-associated genes, poultry isolates showed enhanced growth at 42 °C and greater erythrocyte lysis on chicken blood agar in comparison with human isolates. By combining phenotype information with evolutionary analyses of staphylococcal genomes, we provide evidence of adaptation, following a human-to-poultry host transition. This has important implications for the emergence and dissemination of new pathogenic clones associated with modern agriculture. PMID:28338786

  3. Haem Recognition By a Staphylococcus Aureus NEAT Domain

    SciTech Connect

    Grigg, J.C.; Vermeiren, C.; Heinrichs, D.E.; Murphy, M.E.P.

    2009-06-01

    Successful pathogenic organisms have developed mechanisms to thrive under extreme levels of iron restriction. Haem-iron represents the largest iron reservoir in the human body and is a significant source of iron for some bacterial pathogens. NEAT (NEAr Transporter) domains are found exclusively in a family of cell surface proteins in Gram-positive bacteria. Many NEAT domain-containing proteins, including IsdA in Staphylococcus aureus, are implicated in haem binding. Here, we show that overexpression of IsdA in S. aureus enhances growth and an inactivation mutant of IsdA has a growth defect, compared with wild type, when grown in media containing haem as the sole iron source. Furthermore, the haem-binding property of IsdA is contained within the NEAT domain. Crystal structures of the apo-IsdA NEAT domain and in complex with haem were solved and reveal a clathrin adapter-like beta-sandwich fold with a large hydrophobic haem-binding pocket. Haem is bound with the propionate groups directed at the molecular surface and the iron is co-ordinated solely by Tyr(166). The phenol groups of Tyr(166) and Tyr(170) form an H-bond that may function in regulating haem binding and release. An analysis of IsdA structure-sequence alignments indicate that conservation of Tyr(166) is a predictor of haem binding by NEAT domains.

  4. New epidemiology of Staphylococcus aureus infections in the Middle East.

    PubMed

    Tokajian, S

    2014-07-01

    Staphylococcus aureus is a bacterial pathogen that is distributed worldwide and represents an increasing problem, both in hospitals and in the community. Global transmission of methicillin-resistant S. aureus (MRSA) has been the subject of many studies. Determining the incidence of colonization with community-acquired MRSA in hospitalized patients and outpatients has been the aim of several studies conducted in the Middle East (western Asia). The local epidemiology within countries in this region is changing, owing to the introduction of new strains with the intercontinental exchange of several clones. Sequence type 80-MRSA-IV is one common clone detected in different countries within the region showing country-based differences, and hence more likely to form clonal lineages. MRSA is endemic in this region, and the burden and the difficulty in detecting imported strains are increasing. This is also increasing the risk of domestic and global transmission. To counter the threat associated with the high incidence of MRSA carriage and infections, systematic surveillance of both hospital and community isolates is required, along with appropriate measures designed to limit their spread. Additionally, antibiotic stewardship is needed to contain the further development of the observed resistance and to help in preserving antibiotics as precious therapeutic resources. It is critical for countries in this region to establish both national and international initiatives to develop better measurements designed to limit and control the spread of infections. Finally, more sequence-based studies are needed to better understand the pathogenicity and epidemiology of these important pathogens.

  5. Methicillin-resistant Staphylococcus aureus in diabetic foot infections.

    PubMed

    Eleftheriadou, Ioanna; Tentolouris, Nicholas; Argiana, Vasiliki; Jude, Edward; Boulton, Andrew J

    2010-10-01

    Diabetic foot ulcers are often complicated by infection. Among pathogens, Staphylococcus aureus predominates. The prevalence of methicillin-resistant S. aureus (MRSA) in infected foot ulcers is 15-30% and there is an alarming trend for increase in many countries. There are also data that recognize new strains of MRSA that are resistant to vancomycin. The risk for MRSA isolation increases in the presence of osteomyelitis, nasal carriage of MRSA, prior use of antibacterials or hospitalization, larger ulcer size and longer duration of the ulcer. The need for amputation and surgical debridement increases in patients infected with MRSA. Infections of mild or moderate severity caused by community-acquired MRSA can be treated with cotrimoxazole (trimethoprim/sulfamethoxazole), doxycycline or clindamycin when susceptibility results are available, while severe community-acquired or hospital-acquired MRSA infections should be managed with glycopeptides, linezolide or daptomycin. Dalbavancin, tigecycline and ceftobiprole are newer promising antimicrobial agents active against MRSA that may also have a role in the treatment of foot infections if more data on their efficacy and safety become available.

  6. Fluoroquinolones and risk for methicillin-resistant Staphylococcus aureus, Canada.

    PubMed

    LeBlanc, Louiselle; Pépin, Jacques; Toulouse, Krystel; Ouellette, Marie-France; Coulombe, Marie-Andrée; Corriveau, Marie-Pier; Alary, Marie-Eve

    2006-09-01

    Receipt of fluoroquinolones was the predominant risk factor for Clostridium difficile-associated disease (CDAD) during an epidemic in Quebec, Canada. To determine the role of antimicrobial drugs in facilitating healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection and to compare this role with their effects on methicillin-susceptible S. aureus infection and CDAD, we conducted a retrospective cohort study of patients in a Quebec hospital. For 7371 episodes of care, data were collected on risk factors, including receipt of antimicrobial drugs. Crude and adjusted hazard ratios (AHR) were calculated by Cox regression. Of 150 episodes of MRSA colonization and 23 of MRSA infection, fluoroquinolones were the only antimicrobials that increased risk for colonization (AHR 2.57, 95% confidence interval [CI] 1.84-3.60) and infection (AHR 2.49, 95% CI 1.02-6.07). Effect of antimicrobial drugs on MRSA colonization and infection was similar to effect on CDAD and should be considered when selecting antimicrobial drugs to treat common infections.

  7. Adhesion force of staphylococcus aureus on various biomaterial surfaces.

    PubMed

    Alam, Fahad; Balani, Kantesh

    2017-01-01

    Staphylococcus comprises of more than half of all pathogens in orthopedic implant infections and they can cause major bone infection which can result in destruction of joint and bone. In the current study, adhesion force of bacteria on the surface of various biomaterial surfaces is measured using atomic force microscope (AFM). Staphylococcus aureus was immobilized on an AFM tipless cantilever as a force probe to measure the adhesion force between bacteria and biomaterials (viz. ultra-high molecular weight poly ethylene (UHMWPE), stainless steel (SS), Ti-6Al-4V alloy, hydroxyapatite (HA)). At the contact time of 10s, UHMWPE shows weak adhesion force (~4nN) whereas SS showed strong adhesion force (~15nN) due to their surface energy and surface roughness. Bacterial retention and viability experiment (3M™ petrifilm test, agar plate) dictates that hydroxyapatite shows the lowest vaibility of bacteria, whereas lowest bacterial retention is observed on UHMWPE surface. Similar results were obtained from live/dead staining test, where HA shows 65% viability, whereas on UHMWPE, SS and Ti-6Al-4V, the bacterial viability is 78%, 94% and 97%, respectively. Lower adhesion forces, constrained pull-off distance (of bacterial) and high antibacterial resistance of bioactive-HA makes it a potential biomaterial for bone-replacement arthroplasty.

  8. Healthcare-Associated Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Kumari, Jyoti; Shenoy, Shalini M.; Baliga, Shrikala; Chakrapani, M.; Bhat, Gopalkrishna K.

    2016-01-01

    Objectives: Healthcare-associated methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen worldwide and its multidrug resistance is a major concern. This study aimed to determine the clinical characteristics and antibiotic susceptibility profile of healthcare-associated MRSA with emphasis on resistance to macrolide-lincosamide-streptogramin B (MLSB) phenotypes and vancomycin. Methods: This cross-sectional study was carried out between February 2014 and February 2015 across four tertiary care hospitals in Mangalore, South India. Healthcare-associated infections among 291 inpatients at these hospitals were identified according to the Centers for Disease Control and Prevention guidelines. Clinical specimens were collected based on infection type. S. aureus and MRSA isolates were identified and antibiotic susceptibility tests performed using the Kirby-Bauer disk diffusion method. The minimum inhibitory concentration of vancomycin was determined using the Agar dilution method and inducible clindamycin resistance was detected with a double-disk diffusion test (D-test). Results: Out of 291 healthcare-associated S. aureus cases, 88 were MRSA (30.2%). Of these, 54.6% were skin and soft tissue infections. All of the isolates were susceptible to teicoplanin and linezolid. Four MRSA isolates exhibited intermediate resistance to vancomycin (4.6%). Of the MRSA strains, 10 (11.4%) were constitutive MLSB phenotypes, 31 (35.2%) were inducible MLSB phenotypes and 14 (15.9%) were macrolide-streptogramin B phenotypes. Conclusion: Healthcare-associated MRSA multidrug resistance was alarmingly high. In routine antibiotic susceptibility testing, a D-test should always be performed if an isolate is resistant to erythromycin but susceptible to clindamycin. Determination of the minimum inhibitory concentration of vancomycin is necessary when treating patients with MRSA infections. PMID:27226908

  9. The Staphylococcus aureus FASII bypass escape route from FASII inhibitors.

    PubMed

    Morvan, Claire; Halpern, David; Kénanian, Gérald; Pathania, Amit; Anba-Mondoloni, Jamila; Lamberet, Gilles; Gruss, Alexandra; Gloux, Karine

    2017-10-01

    Antimicrobials targeting the fatty acid synthesis (FASII) pathway are being developed as alternative treatments for bacterial infections. Emergence of resistance to FASII inhibitors was mainly considered as a consequence of mutations in the FASII target genes. However, an alternative and efficient anti-FASII resistance strategy, called here FASII bypass, was uncovered. Bacteria that bypass FASII incorporate exogenous fatty acids in membrane lipids, and thus dispense with the need for FASII. This strategy is used by numerous Gram-positive low GC % bacteria, including streptococci, enterococci, and staphylococci. Some bacteria repress FASII genes once fatty acids are available, and "constitutively" shift to FASII bypass. Others, such as the major pathogen Staphylococcus aureus, can undergo high frequency mutations that favor FASII bypass. This capacity is particularly relevant during infection, as the host supplies the fatty acids needed for bacteria to bypass FASII and thus become resistant to FASII inhibitors. Screenings for anti-FASII resistance in the presence of exogenous fatty acids confirmed that FASII bypass confers anti-FASII resistance among clinical and veterinary isolates. Polymorphisms in S. aureus FASII initiation enzymes favor FASII bypass, possibly by increasing availability of acyl-carrier protein, a required intermediate. Here we review FASII bypass and consequences in light of proposed uses of anti-FASII to treat infections, with a focus on FASII bypass in S. aureus. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. Colostrum Hexasaccharide, a Novel Staphylococcus aureus Quorum-Sensing Inhibitor

    PubMed Central

    Srivastava, A.; Deepak, D.; Singh, B. R.

    2015-01-01

    The discovery of quorum-sensing (QS) systems regulating antibiotic resistance and virulence factors (VFs) has afforded a novel opportunity to prevent bacterial pathogenicity. Dietary molecules have been demonstrated to attenuate QS circuits of bacteria. But, to our knowledge, no study exploring the potential of colostrum hexasaccharide (CHS) in regulating QS systems has been published. In this study, we analyzed CHS for inhibiting QS signaling in Staphylococcus aureus. We isolated and characterized CHS from mare colostrum by high-performance thin-layer chromatography (HPTLC), reverse-phase high-performance liquid chromatography evaporative light-scattering detection (RP-HPLC-ELSD), 1H and 13C nuclear magnetic resonance (NMR), and electrospray ionization mass spectrometry (ESI-MS). Antibiofilm activity of CHS against S. aureus and its possible interference with bacterial QS systems were determined. The inhibition and eradication potentials of the biofilms were studied by microscopic analyses and quantified by 96-well-microtiter-plate assays. Also, the ability of CHS to interfere in bacterial QS by degrading acyl-homoserine lactones (AHLs), one of the most studied signal molecules for Gram-negative bacteria, was evaluated. The results revealed that CHS exhibited promising inhibitory activities against QS-regulated secretion of VFs, including spreading ability, hemolysis, protease, and lipase activities, when applied at a rate of 5 mg/ml. The results of biofilm experiments indicated that CHS is a strong inhibitor of biofilm formation and also has the ability to eradicate it. The potential of CHS to interfere with bacterial QS systems was also examined by degradation of AHLs. Furthermore, it was documented that CHS decreased antibiotic resistance in S. aureus. The results thus give a lead that mare colostrum can be a promising source for isolating a next-generation antibacterial. PMID:25645850

  11. Methicillin-resistant Staphylococcus aureus: a new zoonotic agent?

    PubMed

    Springer, Burkhard; Orendi, Ulrike; Much, Peter; Höger, Gerda; Ruppitsch, Werner; Krziwanek, Karina; Metz-Gercek, Sigrid; Mittermayer, Helmut

    2009-01-01

    Staphylococcus aureus is a major cause of infection in hospitals and the community. One third of the general population is colonized by the bacterium, constituting a risk factor for acquisition of infection with this pathogen. Worldwide, the increasing antibiotic resistance of S. aureus complicates treatment of infection and control measures. Soon after the introduction of methicillin, the first isolates resistant to this antibiotic were reported and named methicillin-resistant S. aureus (MRSA). During the past decade a major change in MRSA epidemiology has been observed: whereas in the past MRSA was almost exclusively regarded a hospital pathogen, the advent of community-acquired MRSA has led to infections in people without hospital-related risk factors. Recent evidence has also identified a link between colonization of livestock and MRSA carriage and infections in people who work with animals. Screening of pigs and pig farmers in the Netherlands revealed high prevalence of MRSA sequence type (ST) 398 and it has become clear that the emergence of ST398 is not just a Dutch problem, as reports on livestock colonization and human infections are appearing worldwide. In Austria, the ST398 lineage has been detected in dust samples from pig breeding facilities and in food samples. Since the first Austrian detection of this emerging lineage in 2006, 21 human isolates, partially associated with infections, have been observed. MRSA has to be regarded as a new emerging zoonotic agent and livestock may constitute a growing reservoir of the ST398 lineage. More information is needed so that control measures to reduce the impact of the emerging MRSA ST398 lineage on public health can be developed and implemented.

  12. Clinical Risk Factors for Infective Endocarditis in Staphylococcus aureus Bacteremia

    PubMed Central

    Chapagain, Bikash; Joshi, Astha; Brennessel, Debra J.

    2017-01-01

    Crucial to the management of staphylococcal bacteremia is an accurate evaluation of associated endocarditis, which has both therapeutic and prognostic implications. Because the clinical presentation of endocarditis can be nonspecific, the judicious use of echocardiography is important in distinguishing patients at high risk of developing endocarditis. In the presence of high-risk clinical features, an early transesophageal echocardiogram is warranted without prior transthoracic echocardiography. The purpose of this study was to investigate the clinical risk factors for staphylococcal infective endocarditis that might warrant earlier transesophageal echocardiography and to describe the incidence of endocarditis in cases of methicillin-resistant and methicillin-sensitive Staphylococcus aureus bacteremia. A retrospective case-control study was conducted by means of chart review of 91 patients consecutively admitted to a community hospital from January 2009 through January 2013. Clinical risk factors of patients with staphylococcal bacteremia were compared with risk factors of patients who had definite diagnoses of infective endocarditis. There were 69 patients with bacteremia alone (76%) and 22 patients with endocarditis (24%), as verified by echocardiography. Univariate analysis showed that diabetes mellitus (P=0.024), the presence of an automatic implantable cardioverter-defibrillator/pacemaker (P=0.006) or a prosthetic heart valve (P=0.003), and recent hospitalization (P=0.048) were significantly associated with developing infective endocarditis in patients with S. aureus bacteremia. The incidence of methicillin-resistant and methicillin-sensitive S. aureus bacteremia was similar in the bacteremia and infective-endocarditis groups (P=0.437). In conclusion, identified high-risk clinical factors in the presence of bacteremia can suggest infective endocarditis. Early evaluation with transesophageal echocardiography might well be warranted. PMID:28265207

  13. Topoisomerase targeting with and resistance to gemifloxacin in Staphylococcus aureus.

    PubMed

    Ince, Dilek; Zhang, Xiamei; Silver, L Christine; Hooper, David C

    2003-01-01

    Gemifloxacin, a novel quinolone with potent activity against Staphylococcus aureus, was 8- to 16-fold more active against wild-type S. aureus than ciprofloxacin. The two- to fourfold increase in the MIC of gemifloxacin in genetically defined grlBA mutants and the twofold increase in a single gyrA mutant, supported by the low frequency of selection of resistant mutants at twice the MIC (7.4 x 10(-11) to 1.1 x 10(-10)), suggested similar targeting of the two enzymes by gemifloxacin. Dual mutations in both gyrase and topoisomerase IV caused a 64- to 128-fold increase in the MIC of gemifloxacin, similar to that seen with ciprofloxacin. Gemifloxacin also had similar activity in vitro against topoisomerase IV and gyrase purified from S. aureus (50% inhibitory concentrations of 0.25 and 0.31 micro g/ml, respectively). This activity was 10- to 20-fold higher than that of ciprofloxacin for topoisomerase IV and 33-fold higher than that for gyrase. In contrast to the in vitro findings, only topoisomerase IV mutants were selected in first-step mutants. Overexpression of the NorA efflux pump had a minimal effect on resistance to gemifloxacin, and a mutation in the promoter region of the gene for NorA was selected only in the sixth step of serial selection of mutants. Our data show that although gemifloxacin targets purified topoisomerase IV and gyrase similarly in vitro, topoisomerase IV is the preferred target in the bacteria. Selection of novel resistance mutations in grlA requires further expansion of quinolone-resistance-determining regions, and their study may provide increased insight into enzyme-quinolone interactions.

  14. Topoisomerase Targeting with and Resistance to Gemifloxacin in Staphylococcus aureus

    PubMed Central

    Ince, Dilek; Zhang, Xiamei; Silver, L. Christine; Hooper, David C.

    2003-01-01

    Gemifloxacin, a novel quinolone with potent activity against Staphylococcus aureus, was 8- to 16-fold more active against wild-type S. aureus than ciprofloxacin. The two- to fourfold increase in the MIC of gemifloxacin in genetically defined grlBA mutants and the twofold increase in a single gyrA mutant, supported by the low frequency of selection of resistant mutants at twice the MIC (7.4 × 10−11 to 1.1 × 10−10), suggested similar targeting of the two enzymes by gemifloxacin. Dual mutations in both gyrase and topoisomerase IV caused a 64- to 128-fold increase in the MIC of gemifloxacin, similar to that seen with ciprofloxacin. Gemifloxacin also had similar activity in vitro against topoisomerase IV and gyrase purified from S. aureus (50% inhibitory concentrations of 0.25 and 0.31 μg/ml, respectively). This activity was 10- to 20-fold higher than that of ciprofloxacin for topoisomerase IV and 33-fold higher than that for gyrase. In contrast to the in vitro findings, only topoisomerase IV mutants were selected in first-step mutants. Overexpression of the NorA efflux pump had a minimal effect on resistance to gemifloxacin, and a mutation in the promoter region of the gene for NorA was selected only in the sixth step of serial selection of mutants. Our data show that although gemifloxacin targets purified topoisomerase IV and gyrase similarly in vitro, topoisomerase IV is the preferred target in the bacteria. Selection of novel resistance mutations in grlA requires further expansion of quinolone-resistance-determining regions, and their study may provide increased insight into enzyme-quinolone interactions. PMID:12499202

  15. Relationship Between Maternal and Neonatal Staphylococcus aureus Colonization

    PubMed Central

    Tedeschi, Sara; Saye, Elizabeth J.; McKenna, Brian D.; Langdon, Weston; Wright, Jesse P.; Alsentzer, Andrew; Arnold, Sandra; Saville, Benjamin R.; Wang, Wenli; Thomsen, Isaac; Creech, C. Buddy

    2012-01-01

    OBJECTIVE: The study aimed to assess whether maternal colonization with Staphylococcus aureus during pregnancy or at delivery was associated with infant staphylococcal colonization. METHODS: For this prospective cohort study, women were enrolled at 34 to 37 weeks of gestation between 2007 and 2009. Nasal and vaginal swabs for culture were obtained at enrollment; nasal swabs were obtained from women and their infants at delivery and 2- and 4-month postbirth visits. Logistic regression was used to determine whether maternal colonization affected infant colonization. RESULTS: Overall, 476 and 471 mother-infant dyads had complete data for analysis at enrollment and delivery, respectively. Maternal methicillin-resistant S aureus (MRSA) colonization occurred in 10% to 17% of mothers, with the highest prevalence at enrollment. Infant MRSA colonization peaked at 2 months of age, with 20.9% of infants colonized. Maternal staphylococcal colonization at enrollment increased the odds of infant staphylococcal colonization at birth (odds ratio; 95% confidence interval: 4.8; 2.4–9.5), hospital discharge (2.6; 1.3–5.0), at 2 months of life (2.7; 1.6–4.3), and at 4 months of life (2.0; 1.1–3.5). Similar results were observed for maternal staphylococcal colonization at delivery. Fifty maternal-infant dyads had concurrent MRSA colonization: 76% shared isolates of the same pulsed-field type, and 30% shared USA300 isolates. Only 2 infants developed staphylococcal disease. CONCLUSIONS: S aureus colonization (including MRSA) was extremely common in this cohort of maternal-infant pairs. Infants born to mothers with staphylococcal colonization were more likely to be colonized, and early postnatal acquisition appeared to be the primary mechanism. PMID:22473373

  16. Repurposing Salicylanilide Anthelmintic Drugs to Combat Drug Resistant Staphylococcus aureus

    PubMed Central

    Rajamuthiah, Rajmohan; Fuchs, Beth Burgwyn; Conery, Annie L.; Kim, Wooseong; Jayamani, Elamparithi; Kwon, Bumsup; Ausubel, Frederick M.; Mylonakis, Eleftherios

    2015-01-01

    Staphylococcus aureus is a Gram-positive bacterium that has become the leading cause of hospital acquired infections in the US. Repurposing Food and Drug Administration (FDA) approved drugs for antimicrobial therapy involves lower risks and costs compared to de novo development of novel antimicrobial agents. In this study, we examined the antimicrobial properties of two commercially available anthelmintic drugs. The FDA approved drug niclosamide and the veterinary drug oxyclozanide displayed strong in vivo and in vitro activity against methicillin resistant S. aureus (minimum inhibitory concentration (MIC): 0.125 and 0.5 μg/ml respectively; minimum effective concentration: ≤ 0.78 μg/ml for both drugs). The two drugs were also effective against another Gram-positive bacteria Enterococcus faecium (MIC 0.25 and 2 μg/ml respectively), but not against the Gram-negative species Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter aerogenes. The in vitro antimicrobial activity of niclosamide and oxyclozanide were determined against methicillin, vancomycin, linezolid or daptomycin resistant S. aureus clinical isolates, with MICs at 0.0625-0.5 and 0.125-2 μg/ml for niclosamide and oxyclozanide respectively. A time-kill study demonstrated that niclosamide is bacteriostatic, whereas oxyclozanide is bactericidal. Interestingly, oxyclozanide permeabilized the bacterial membrane but neither of the anthelmintic drugs exhibited demonstrable toxicity to sheep erythrocytes. Oxyclozanide was non-toxic to HepG2 human liver carcinoma cells within the range of its in vitro MICs but niclosamide displayed toxicity even at low concentrations. These data show that the salicylanilide anthelmintic drugs niclosamide and oxyclozanide are suitable candidates for mechanism of action studies and further clinical evaluation for treatment of staphylococcal infections. PMID:25897961

  17. Inhibition of major integrin αV β3 reduces Staphylococcus aureus attachment to sheared human endothelial cells.

    PubMed

    McDonnell, C J; Garciarena, C D; Watkin, R L; McHale, T M; McLoughlin, A; Claes, J; Verhamme, P; Cummins, P M; Kerrigan, S W

    2016-12-01

    Essentials Staphylococcus aureus (S. aureus) binds and impairs function of vascular endothelial cells (EC). We investigated the molecular signals triggered by S. aureus adhesion to EC. Inhibition of the EC integrin αVβ3 reduces S. aureus binding and rescues EC function. αVβ3 blockade represents an attractive target to treat S. aureus bloodborne infections.

  18. Ultrastructural Study on the Antibacterial Activity of Artonin E versus Streptomycin against Staphylococcus aureus Strains.

    PubMed

    Zajmi, Asdren; Mohd Hashim, Najihah; Noordin, Mohamed Ibrahim; Khalifa, Shaden A M; Ramli, Faiqah; Mohd Ali, Hapipah; El-Seedi, Hesham R

    2015-01-01

    Staphylococci are facultative anaerobes, perfectly spherical un-encapsulated cocci, with a diameter not exceeding 1 micrometer in diameter. Staphylococcus aureus are generally harmless and remain confined to the skin unless they burrow deep into the body, causing life-threatening infections in bones, joints, bloodstream, heart valves and lungs. Among the 20 medically important staphylococci species, Staphylococcus aureus is one of the emerging human pathogens. Streptomycin had its highest potency against Staphylococcus infections despite the likelihood of getting a resistant type of staphylococcus strains. Methicillin-resistant S. aureus (MRSA) is the persister type of Staphylococcus aureus and was evolved after decades of antibiotic misuse. Inadequate penetration of the antibiotic is one of the principal factors related to success/failure of the therapy. The active drug needs to reach the bacteria at concentrations necessary to kill or suppress the pathogen's growth. In turn the effectiveness of the treatment relied on the physical properties of Staphylococcus aureus. Thus understanding the cell integrity, shape and roughness is crucial to the overall influence of the therapeutic agent on S. aureus of different origins. Hence our experiments were designed to clarify ultrastructural changes of S. aureus treated with streptomycin (synthetic compound) in comparison to artonin E (natural compound). In addition to the standard in vitro microbial techniques, we used transmission electron microscopy to study the disrupted cell architecture under antibacterial regimen and we correlate this with scanning electron microscopy (SEM) to compare results of both techniques.

  19. Genomic organization of a vancomycin-resistant Staphylococcus aureus.

    PubMed

    Mirani, Zulfiqar Ali; Jamil, Nusrat

    2013-02-01

    To study the genomic organization of vancomycin resistance in a local isolate of vancomycin resistant Staphylococcus aureus (VRSA). Experimental study. Department of Microbiology, University of Karachi, January 2008 through December 2010. A vancomycin-resistant Staphylococcus aureus (VRSA-CP2) isolate (MIC 16 μg/ml) was isolated from a local hospital of Karachi. Species identification was confirmed by Gram staining, standard biochemical tests and PCR amplification of the nuc gene. The vancomycin MIC was re-confirmed by E-test. For the genetic determination of vancomycin resistance, in-vitro amplification of vanA cassette was performed by using plasmid DNA of CP2, CP2's transformant as template on MWG Thermo-Cycler. Amplified products of vanR, vanS, vanH, vanA, vanY, orf2, orf1D, orf2E, orf-Rev and IS element genes were subjected to Sanger's electrophoresis based sequence determination using specific primers. The Basic Local Alignment Search Tool (BLAST) algorithm was used to identify sequences in GenBank with similarities to the vanA cassette genes. The vancomycin-resistant isolate CP2 was found to be resistant to oxacillin, chloramphenicol, erythromycin, rifampicin, gentamicin, tetracycline and ciprofloxacin, as well. The isolate CP2 revealed four bands: one of large molecular size ~56.4 kb and three of small size ~6.5 kb, ~6.1 kb and ~1.5 kb by agarose gel electrophoresis indicating the presence of 3 plasmids. The plasmid DNA of isolate CP2 was analyzed by PCR for the presence of the van cassettes with each of the vanA , vanB and vanC specific primers. It carried vanA cassette, which comprises of vanR, vanS, vanH, vanA, vanY, and orf2. The vanA cassette of isolate CP2 also carried an insertion element (IS). However, it did not show the PCR product for orf1. Vancomycin resistance was successfully transferred from the donor CP2 to a vancomycin-sensitive recipient S. aureus. The MIC of vancomycin for the transformant was 16 μg/ml, similar to the parent isolate CP2

  20. Exposure of Staphylococcus aureus to Subinhibitory Concentrations of β-Lactam Antibiotics Induces Heterogeneous Vancomycin-Intermediate Staphylococcus aureus

    PubMed Central

    Roch, Mélanie; Clair, Perrine; Renzoni, Adriana; Reverdy, Marie-Elisabeth; Dauwalder, Olivier; Bes, Michèle; Martra, Annie; Freydière, Anne-Marie; Laurent, Frédéric; Reix, Philippe; Dumitrescu, Oana

    2014-01-01

    Glycopeptides are known to select for heterogeneous vancomycin-intermediate Staphylococcus aureus (h-VISA) from susceptible strains. In certain clinical situations, h-VISA strains have been isolated from patients without previous exposure to glycopeptides, such as cystic fibrosis patients, who frequently receive repeated treatments with beta-lactam antibiotics. Our objective was to determine whether prolonged exposure to beta-lactam antibiotics can induce h-VISA. We exposed 3 clinical vancomycin-susceptible methicillin-resistant Staphylococcus aureus (MRSA) strains to ceftazidime, ceftriaxone, imipenem, and vancomycin (as a control) at subinhibitory concentrations for 18 days in vitro. Population analyses showed progressive increases in vancomycin resistance; seven of the 12 derived strains obtained after induction were classified as h-VISA according to the following criteria: area under the curve (AUC) on day 18/AUC of Mu3 of ≥90% and/or growth on brain heart infusion (BHI) agar with 4 mg/liter vancomycin. The derived isolates had thickened cell walls proportional to the level of glycopeptide resistance. Genes known to be associated with glycopeptide resistance (vraSR, yvqF, SA1703, graRS, walKR, and rpoB) were PCR sequenced; no de novo mutations were observed upon beta-lactam exposure. To determine whether trfA, a gene encoding a glycopeptide resistance factor, was essential in the selection of h-VISA upon beta-lactam pressure, a trfA-knockout strain was generated by allelic replacement. Indeed, beta-lactam exposure of this mutated strain showed no capacity to induce vancomycin resistance. In conclusion, these results showed that beta-lactam antibiotics at subinhibitory concentrations can induce intermediate vancomycin resistance in vitro. This induction required an intact trfA locus. Our results suggest that prior use of beta-lactam antibiotics can compromise vancomycin efficacy in the treatment of MRSA infections. PMID:24957836

  1. Exposure of Staphylococcus aureus to subinhibitory concentrations of β-lactam antibiotics induces heterogeneous vancomycin-intermediate Staphylococcus aureus.

    PubMed

    Roch, Mélanie; Clair, Perrine; Renzoni, Adriana; Reverdy, Marie-Elisabeth; Dauwalder, Olivier; Bes, Michèle; Martra, Annie; Freydière, Anne-Marie; Laurent, Frédéric; Reix, Philippe; Dumitrescu, Oana; Vandenesch, François

    2014-09-01

    Glycopeptides are known to select for heterogeneous vancomycin-intermediate Staphylococcus aureus (h-VISA) from susceptible strains. In certain clinical situations, h-VISA strains have been isolated from patients without previous exposure to glycopeptides, such as cystic fibrosis patients, who frequently receive repeated treatments with beta-lactam antibiotics. Our objective was to determine whether prolonged exposure to beta-lactam antibiotics can induce h-VISA. We exposed 3 clinical vancomycin-susceptible methicillin-resistant Staphylococcus aureus (MRSA) strains to ceftazidime, ceftriaxone, imipenem, and vancomycin (as a control) at subinhibitory concentrations for 18 days in vitro. Population analyses showed progressive increases in vancomycin resistance; seven of the 12 derived strains obtained after induction were classified as h-VISA according to the following criteria: area under the curve (AUC) on day 18/AUC of Mu3 of ≥90% and/or growth on brain heart infusion (BHI) agar with 4 mg/liter vancomycin. The derived isolates had thickened cell walls proportional to the level of glycopeptide resistance. Genes known to be associated with glycopeptide resistance (vraSR, yvqF, SA1703, graRS, walKR, and rpoB) were PCR sequenced; no de novo mutations were observed upon beta-lactam exposure. To determine whether trfA, a gene encoding a glycopeptide resistance factor, was essential in the selection of h-VISA upon beta-lactam pressure, a trfA-knockout strain was generated by allelic replacement. Indeed, beta-lactam exposure of this mutated strain showed no capacity to induce vancomycin resistance. In conclusion, these results showed that beta-lactam antibiotics at subinhibitory concentrations can induce intermediate vancomycin resistance in vitro. This induction required an intact trfA locus. Our results suggest that prior use of beta-lactam antibiotics can compromise vancomycin efficacy in the treatment of MRSA infections.

  2. Ethanol and Isopropyl Alcohol Exposure Increases Biofilm Formation in Staphylococcus aureus and Staphylococcus epidermidis.

    PubMed

    Luther, Megan K; Bilida, Sarah; Mermel, Leonard A; LaPlante, Kerry L

    2015-06-01

    Alcohols, including ethanol and isopropyl alcohol, are used in clinical practice for disinfection and infection prevention. Recent studies, however, demonstrate that alcohols may enhance biofilm production in Staphylococci. We quantified biofilm formation in the presence of ethanol and isopropyl alcohol in six different, well-characterized strains of Staphylococcus epidermidis and Staphylococcus aureus. After 24 h of biofilm development, each strain was exposed to normal saline (NS), ethanol, or isopropyl alcohol (40%, 60%, 80% and 95%) for additional 24 h incubation. Adherent biofilms were stained and optical density was determined. Viability of strains was also determined after alcohol exposure. Ethanol increased biofilm formation in all six strains compared to normal saline (p < 0.05). There was increased biofilm formation with increasing ethanol concentration. Isopropyl alcohol also increased biofilm formation with increasing alcohol concentration in all six strains (p < 0.01 vs NS). The slime-negative, chemical mutant strain of S. epidermidis increased biofilm formation after exposure to both alcohols, likely reverting back its primary phenotype through modulation of the intercellular adhesin repressor. All strains demonstrated viability after exposure to each alcohol concentration, though viability was decreased. Ethanol and isopropyl alcohol exposure increases biofilm formation of S. aureus and S. epidermidis at concentrations used in clinical settings. Ethanol and isopropyl alcohol did not eradicate viable Staphylococci from formed biofilm.

  3. Concomitant genotyping revealed diverse spreading between methicillin-resistant Staphylococcus aureus and methicillin-susceptible Staphylococcus aureus in central Taiwan.

    PubMed

    Ho, Cheng-Mao; Lin, Chien-Yu; Ho, Mao-Wang; Lin, Hsiao-Chuan; Peng, Ching-Tien; Lu, Jang-Jih

    2016-06-01

    Staphylococcus aureus is a versatile bacterium, which can lead to various infectious diseases. Various molecular typing methods are applied to the evolution and epidemiology surveys of S. aureus, mostly for methicillin-resistant S. aureus (MRSA). However, methicillin-susceptible S. aureus (MSSA) is still an important pathogen, but their molecular typing is evaluated infrequently. Pulsed-field gel electrophoresis (PFGE), spa typing, and detection of five virulent genes for 95 MRSA and 56 MSSA isolates (July-December 2008 and July 2008-December 2009, respectively) during an overlapping period were performed. More diversity was found in MSSA isolates (23 pulsotypes and 25 spa types, excluding 4 new-type and 1 nontypable isolates for spa typing) than in MRSA isolates (19 pulsotypes and 16 spa types, excluding 1 new-type and 1 nontypable isolates for spa typing). By spa typing, t002 (n = 30), t037 (n = 23), t437 (n = 21), t234 (n = 3), t1081 (n = 3), and t1094 (n = 3) were the six major MRSA clones. For MSSA isolates, t189 (n = 13), t437 (n = 4), t084 (n = 3), t213 (n = 3), t701 (n = 3), and t7200 (n = 3) were the six major types. Combining PFGE and spa typing, there were five combinations (pulsotype + spa type) that contained both MRSA and MSSA isolates (pulsotype 9-t437, pulsotype 15-t037, pulsotype 19-t002, pulsotype 21-t002, and pulsotype 28-t1081). For all 151 S. aureus or 95 MRSA isolates, the PFGE typing had more discrimination power, but spa typing had larger discrimination index for 56 MSSA isolates. In conclusion, there were different predominant MRSA and MSSA clones clinically. Continuing longitudinal tracking of molecular typing is necessary for elucidating the evolution of this important clinical pathogen. Copyright © 2014. Published by Elsevier B.V.

  4. Polymyxin-Coagulase-Deoxyribonuclease-Agar: a Selective Isolation Medium for Staphylococcus aureus1

    PubMed Central

    Orth, D. S.; Anderson, A. W.

    1970-01-01

    Fibrin halos developed around coagulase-positive Staphylococcus aureus colonies, and deoxyribonuclease production was detected by using a developing solution containing 1 mg of methyl green per ml. PMID:4098639

  5. Hyperimmunoglobulin E syndrome with persistent vertebral osteomyelitis due to methicillin-resistant Staphylococcus aureus

    PubMed Central

    Wong, San S.; Smith, Peter R.; Ayaz, Asim; Sepkowitz, Douglas

    2014-01-01

    We report a case of vertebral osteomyelitis due to methicillin-resistant Staphylococcus aureus (MRSA) with a slowly progressive, relatively asymptomatic course in a young woman with suspected hyperimmunoglobulin E syndrome (Job's syndrome). PMID:26839768

  6. Local circulating clones of Staphylococcus aureus in Ecuador.

    PubMed

    Zurita, Jeannete; Barba, Pedro; Ortega-Paredes, David; Mora, Marcelo; Rivadeneira, Sebastián

    The spread of pandemic Staphylococcus aureus clones, mainly methicillin-resistant S. aureus (MRSA), must be kept under surveillance to assemble an accurate, local epidemiological analysis. In Ecuador, the prevalence of the USA300 Latin American variant clone (USA300-LV) is well known; however, there is little information about other circulating clones. The aim of this work was to identify the sequence types (ST) using a Multiple-Locus Variable number tandem repeat Analysis 14-locus genotyping approach. We analyzed 132 S. aureus strains that were recovered from 2005 to 2013 and isolated in several clinical settings in Quito, Ecuador. MRSA isolates composed 46.97% (62/132) of the study population. Within MRSA, 37 isolates were related to the USA300-LV clone (ST8-MRSA-IV, Panton-Valentine Leukocidin [PVL] +) and 10 were related to the Brazilian clone (ST239-MRSA-III, PVL-). Additionally, two isolates (ST5-MRSA-II, PVL-) were related to the New York/Japan clone. One isolate was related to the Pediatric clone (ST5-MRSA-IV, PVL-), one isolate (ST45-MRSA-II, PVL-) was related to the USA600 clone, and one (ST22-MRSA-IV, PVL-) was related to the epidemic UK-EMRSA-15 clone. Moreover, the most prevalent MSSA sequence types were ST8 (11 isolates), ST45 (8 isolates), ST30 (8 isolates), ST5 (7 isolates) and ST22 (6 isolates). Additionally, we found one isolate that was related to the livestock associated S. aureus clone ST398. We conclude that in addition to the high prevalence of clone LV-ST8-MRSA-IV, other epidemic clones are circulating in Quito, such as the Brazilian, Pediatric and New York/Japan clones. The USA600 and UK-EMRSA-15 clones, which were not previously described in Ecuador, were also found. Moreover, we found evidence of the presence of the livestock associated clone ST398 in a hospital environment. Copyright © 2016 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  7. Quantitative microbial risk assessment for Staphylococcus aureus and Staphylococcus enterotoxin A in raw milk.

    PubMed

    Heidinger, Joelle C; Winter, Carl K; Cullor, James S

    2009-08-01

    A quantitative microbial risk assessment was constructed to determine consumer risk from Staphylococcus aureus and staphylococcal enterotoxin in raw milk. A Monte Carlo simulation model was developed to assess the risk from raw milk consumption using data on levels of S. aureus in milk collected by the University of California-Davis Dairy Food Safety Laboratory from 2,336 California dairies from 2005 to 2008 and using U.S. milk consumption data from the National Health and Nutrition Examination Survey of 2003 and 2004. Four modules were constructed to simulate pathogen growth and staphylococcal enterotoxin A production scenarios to quantify consumer risk levels under various time and temperature storage conditions. The three growth modules predicted that S. aureus levels could surpass the 10(5) CFU/ml level of concern at the 99.9th or 99.99th percentile of servings and therefore may represent a potential consumer risk. Results obtained from the staphylococcal enterotoxin A production module predicted that exposure at the 99.99th percentile could represent a dose capable of eliciting staphylococcal enterotoxin intoxication in all consumer age groups. This study illustrates the utility of quantitative microbial risk assessments for identifying potential food safety issues.

  8. Bacteriophage Therapy for Staphylococcus aureus Biofilm-Infected Wounds: A New Approach to Chronic Wound Care

    DTIC Science & Technology

    2013-02-01

    EXPERIMENTAL Bacteriophage Therapy for Staphylococcus aureus Biofilm– Infected Wounds: A New Approach to Chronic Wound Care Akhil K. Seth, M.D...efficacy of a species-specific bacteriophage against Staphylococcus aureus biofilm– infected wounds using a validated, quantitative, rabbit ear model. Methods...Bacteriophages can be an effective topical therapy against S. au- reus biofilm– infected wounds in the setting of a deficient (mutant) or disrupted

  9. Annual Surveillance Summary: Methicillin Resistant Staphylococcus aureus (MRSA) Infections in the Military Health System (MHS), 2016

    DTIC Science & Technology

    2017-06-30

    Staphylococcus aureus (MRSA) incidence and prevalence among all beneficiaries seeking care within the Military Health System (MHS). This report...Comparison of community- and health care -associated methicillin-resistant Staphylococcus aureus infection. JAMA. 2003;290(22):2976-84. 10. Patel...community‐associated CHCS  Composite  Health   Care  System CO  community‐onset CTS  Contingency Tracking System CY  calendar year DMDC  Defense Manpower Data

  10. Performance of CHROMagar MRSA Medium for Detection of Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Diederen, Bram; van Duijn, Inge; van Belkum, Alex; Willemse, Piet; van Keulen, Peter; Kluytmans, Jan

    2005-01-01

    CHROMagar MRSA was evaluated for its ability to identify methicillin-resistant Staphylococcus aureus (MRSA). A well-defined collection consisting of 216 MRSA strains and 241 methicillin-susceptible Staphylococcus aureus isolates was used. The sensitivity of CHROMagar MRSA after 24 h of incubation was 95.4%, increasing to 100% after 48 h. The specificity was already 100% after 24 h. PMID:15815020

  11. Preparation of 8-hydroxyquinoline derivatives as potential antibiotics against Staphylococcus aureus.

    PubMed

    Lam, Kim-Hung; Gambari, Roberto; Lee, Kenneth Ka-Ho; Chen, Yi-Xin; Kok, Stanton Hon-Lung; Wong, Raymond Siu-Ming; Lau, Fung-Yi; Cheng, Chor-Hing; Wong, Wai-Yeung; Bian, Zhao-Xiang; Chan, Albert Sun-Chi; Tang, Johnny Cheuk-On; Chui, Chung-Hin

    2014-01-01

    This work describes the preparation of quinoline compounds as possible anti-bacterial agents. The synthesized quinoline derivatives show anti-bacterial activity towards Staphylococcus aureus. It is interesting to observe that the synthetic 5,7-dibromo-2-methylquinolin-8-ol (4) shows a similar minimum inhibitory concentration of 6.25μg/mL as compared to that of methicillin (3.125μg/mL) against Staphylococcus aureus. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Antibiotic treatment for acute haematogenous osteomyelitis of childhood: moving towards shorter courses and oral administration.

    PubMed

    Pääkkönen, M; Peltola, H

    2011-10-01

    Acute haematogenous osteomyelitis (AHOM) of childhood usually affects the long bones of the lower limbs. Although almost any agent may cause AHOM, Staphylococcus aureus is the most common bacterium, followed by Streptococcus pneumoniae and, in some countries, Salmonella spp. and Kingella kingae. Magnetic resonance imaging (MRI) has improved the diagnostic accuracy of traditional radiography and scintigraphy. Except for the pre-treatment diagnostic sample from bone before the institution of antibiotic therapy, no other surgery is usually required. Traditionally, non-neonatal AHOM has been treated with a 1-3-month course of antibiotics, including an intravenous (i.v.) phase for the first weeks, but recent prospective randomised studies challenge this approach. For most uncomplicated cases, a course of 20 days including an i.v. period of 2-4 days suffices, provided large enough doses of a well-absorbed agent (clindamycin or a first-generation cephalosporin, local resistance permitting) are used, administration is four times daily and most symptoms and signs subside within a few days. Serum C-reactive protein (CRP) is a good guide in monitoring the course of illness, and the antimicrobial can usually be discontinued if CRP has decreased to <20 mg/L. Newer and costly agents, such as linezolid, should be reserved for cases due to resistant S. aureus strains. AHOM in neonates and immunocompromised patients probably requires a different approach. Because sequelae may develop slowly, follow-up for at least 1 year post hospitalisation is recommended.

  13. Livestock-associated Staphylococcus aureus on Polish pig farms

    PubMed Central

    Mroczkowska, Aneta; Żmudzki, Jacek; Marszałek, Natalia; Orczykowska-Kotyna, Monika; Komorowska, Iga; Nowak, Agnieszka; Grzesiak, Anna; Czyżewska-Dors, Ewelina; Dors, Arkadiusz; Pejsak, Zygmunt; Hryniewicz, Waleria; Wyszomirski, Tomasz; Empel, Joanna

    2017-01-01

    Background Livestock-associated Staphylococcus aureus (LA-SA) draws increasing attention due to its particular ability to colonize farm animals and be transmitted to people, which in turn leads to its spread in the environment. The aim of the study was to determine the dissemination of LA-SA on pig farms selected throughout Poland, characterize the population structure of identified S. aureus, and assess the prevalence of LA-SA carriage amongst farmers and veterinarians being in contact with pigs. Methods and findings The study was conducted on 123 pig farms (89 farrow-to-finish and 34 nucleus herds), located in 15 out of 16 provinces of Poland. Human and pig nasal swabs, as well as dust samples were analyzed. S. aureus was detected on 79 (64.2%) farms from 14 provinces. Amongst these farms LA-SA-positive farms dominated (71/79, 89.9%, 95% CI [81.0%, 95.5%]). The prevalence of LA-MRSA-positive farms was lower than LA-MSSA-positive (36.6% of LA-SA-positive farms, 95% CI [25.5%, 48.9%] vs. 74.6%, 95% CI [62.9%, 84.2%]). In total, 190 S. aureus isolates were identified: 72 (38%) MRSA and 118 (62%) methicillin-susceptible S. aureus (MSSA), of which 174 (92%) isolates were classified to three livestock-associated lineages: CC398 (73%), CC9 (13%), and CC30/ST433 (6%). All CC398 isolates belonged to the animal clade. Four LA-MRSA clones were detected: ST433-IVa(2B) clone (n = 8, 11%), described to the best of our knowledge for the first time, and three ST398 clones (n = 64, 89%) with the most prevalent being ST398-V(5C2&5)c, followed by ST398-V(5C2), and ST398-IVa(2B). Nasal carriage of LA-SA by pig farmers was estimated at 13.2% (38/283), CC398 carriage at 12.7% (36/283) and ST398-MRSA carriage at 3.2% (9/283), whereas by veterinarians at 21.1% (8/38), 18.4% (7/38) and 10.5% (4/38), respectively. Conclusions The prevalence of LA-MRSA-positive pig farms in Poland has increased considerably since 2008, when the first MRSA EU baseline survey was conducted in Europe. On

  14. Livestock-associated Staphylococcus aureus on Polish pig farms.

    PubMed

    Mroczkowska, Aneta; Żmudzki, Jacek; Marszałek, Natalia; Orczykowska-Kotyna, Monika; Komorowska, Iga; Nowak, Agnieszka; Grzesiak, Anna; Czyżewska-Dors, Ewelina; Dors, Arkadiusz; Pejsak, Zygmunt; Hryniewicz, Waleria; Wyszomirski, Tomasz; Empel, Joanna

    2017-01-01

    Livestock-associated Staphylococcus aureus (LA-SA) draws increasing attention due to its particular ability to colonize farm animals and be transmitted to people, which in turn leads to its spread in the environment. The aim of the study was to determine the dissemination of LA-SA on pig farms selected throughout Poland, characterize the population structure of identified S. aureus, and assess the prevalence of LA-SA carriage amongst farmers and veterinarians being in contact with pigs. The study was conducted on 123 pig farms (89 farrow-to-finish and 34 nucleus herds), located in 15 out of 16 provinces of Poland. Human and pig nasal swabs, as well as dust samples were analyzed. S. aureus was detected on 79 (64.2%) farms from 14 provinces. Amongst these farms LA-SA-positive farms dominated (71/79, 89.9%, 95% CI [81.0%, 95.5%]). The prevalence of LA-MRSA-positive farms was lower than LA-MSSA-positive (36.6% of LA-SA-positive farms, 95% CI [25.5%, 48.9%] vs. 74.6%, 95% CI [62.9%, 84.2%]). In total, 190 S. aureus isolates were identified: 72 (38%) MRSA and 118 (62%) methicillin-susceptible S. aureus (MSSA), of which 174 (92%) isolates were classified to three livestock-associated lineages: CC398 (73%), CC9 (13%), and CC30/ST433 (6%). All CC398 isolates belonged to the animal clade. Four LA-MRSA clones were detected: ST433-IVa(2B) clone (n = 8, 11%), described to the best of our knowledge for the first time, and three ST398 clones (n = 64, 89%) with the most prevalent being ST398-V(5C2&5)c, followed by ST398-V(5C2), and ST398-IVa(2B). Nasal carriage of LA-SA by pig farmers was estimated at 13.2% (38/283), CC398 carriage at 12.7% (36/283) and ST398-MRSA carriage at 3.2% (9/283), whereas by veterinarians at 21.1% (8/38), 18.4% (7/38) and 10.5% (4/38), respectively. The prevalence of LA-MRSA-positive pig farms in Poland has increased considerably since 2008, when the first MRSA EU baseline survey was conducted in Europe. On Polish pig farms CC398 of the animal clade

  15. Biochemical and Molecular Analysis of Staphylococcus aureus Clinical Isolates from Hospitalized Patients

    PubMed Central

    Karmakar, Amit; Dua, Parimal; Ghosh, Chandradipa

    2016-01-01

    Staphylococcus aureus is opportunistic human as well as animal pathogen that causes a variety of diseases. A total of 100 Staphylococcus aureus isolates were obtained from clinical samples derived from hospitalized patients. The presumptive Staphylococcus aureus clinical isolates were identified phenotypically by different biochemical tests. Molecular identification was done by PCR using species specific 16S rRNA primer pairs and finally 100 isolates were found to be positive as Staphylococcus aureus. Screened isolates were further analyzed by several microbiological diagnostics tests including gelatin hydrolysis, protease, and lipase tests. It was found that 78%, 81%, and 51% isolates were positive for gelatin hydrolysis, protease, and lipase activities, respectively. Antibiogram analysis of isolated Staphylococcus aureus strains with respect to different antimicrobial agents revealed resistance pattern ranging from 57 to 96%. Our study also shows 70% strains to be MRSA, 54.3% as VRSA, and 54.3% as both MRSA and VRSA. All the identified isolates were subjected to detection of mecA, nuc, and hlb genes and 70%, 84%, and 40% were found to harbour mecA, nuc, and hlb genes, respectively. The current investigation is highly important and informative for the high level multidrug resistant Staphylococcus aureus infections inclusive also of methicillin and vancomycin. PMID:27366185

  16. Photodynamic therapy controls of Staphylococcus aureus intradermal infection in mice.

    PubMed

    Almeida, Palloma Porto; Pereira, Ítalo Sousa; Rodrigues, Karine Bitencourt; Leal, Lorena Santos; Marques, Andressa Souza; Rosa, Luciano Pereira; da Silva, Francine Cristina; da Silva, Robson Amaro Augusto

    2017-08-01

    Infections caused by Staphylococcus aureus lead to skin infections, as well as soft tissues and bone infections. Given the communal resistance to antibiotics developed by strains of this bacterium, photodynamic therapy emerges as a promising alternative treatment to control and cure infections. Females of the Balb/C mice were infected with 10(8) CFU of methicillin-resistant S. aureus (MRSA) and divided into four distinct groups: P-L- (negative control group), P+L- (group exposed only to curcumin), P-L+ (group exposed only to LED incidence of 450 nm, 75 mW/cm(2), and 54 J/cm(2) for 10 min), and P+L+ (group exposed to curcumin followed by 10 min of LED irradiation) (n = 24). The mice were euthanized 48 and 72 h after infection, and biologic materials were collected for analysis of the bacterial load, peripheral blood leukocyte counts, and draining lymph nodes cell counts. The normalization of data was checked and the ANOVA test was applied. The bacterial load in the draining lymph node of P+L+ group was lower when compared to the control groups 72 h post infection (p < 0.0001), indicating that the LED incidence associated with curcumin controls of the staphylococci intradermal infection. The number of the total lymph node cells shows to be lower than control groups in the two availed times (p < 0.01). The histological analysis and the counting of white blood cells did not show differences among cells in the blood and in the tissue of infection. This is the first report showing that photodynamic therapy may be effective against MRSA infection in a murine model of intradermal infection.

  17. Inducible NorA-mediated multidrug resistance in Staphylococcus aureus.

    PubMed Central

    Kaatz, G W; Seo, S M

    1995-01-01

    The NorA protein of Staphylococcus aureus mediates the active efflux of hydrophilic fluoroquinolones from the cell, conferring low-level resistance upon the organism. The protein also is capable of transporting additional structurally diverse compounds, indicating that it has a broad substrate specificity. Increased transcription of the norA gene, leading to a greater quantity of the NorA protein within the cytoplasmic membrane, is felt to be the mechanism by which strains possessing such changes resist fluoroquinolones. S. aureus SA-1199 and its in vivo-selected derivative SA-1199B are fluoroquinolone-susceptible and -resistant isolates, respectively; SA-1199B resists hydrophilic fluoroquinolones via a NorA-mediated mediated mechanism in a constitutive manner. SA-1199-3 is an in vitro-produced derivative of SA-1199 in which NorA-mediated multidrug resistance is expressed inducibly. Compared with organisms exposed to subinhibitory concentrations of a NorA substrate for the first time, preexposure of SA-1199-3 to such a compound followed by growth in the presence of that substrate results in the elimination of a 2- to 6-h period of organism killing that occurs prior to the onset of logarithmic growth. The uptake of radiolabeled fluoroquinolone is markedly reduced by preexposure of SA-1199-3 to NorA substrates: such prior exposure also results in a dramatic increase in RNa transcripts that hybridize with a norA probe. Preexposure of SA-1199 and SA-1199B to such substrates results in small increases or no increases in these transcripts. No sequence differences between SA-1199 and SA-1199-3 within the norA gene or flanking DNA were found. It appears likely that the regulation of norA in SA-1193, which may be effected by one or more genetic loci outside the norA region of the chromosome, differs from that of SA-1199 and SA-1199B. PMID:8592996

  18. Functionalized polyanilines disrupt Pseudomonas aeruginosa and Staphylococcus aureus biofilms.

    PubMed

    Gizdavic-Nikolaidis, Marija R; Pagnon, Joanne C; Ali, Naseem; Sum, Reuben; Davies, Noel; Roddam, Louise F; Ambrose, Mark

    2015-12-01

    The purpose of the present study was to investigate the antimicrobial effects of functionalized polyanilines (fPANIs) against stationary phase cells and biofilms of Pseudomonas aeruginosa and Staphylococcus aureus using homopolymer of sulfanilic acid (poly-SO3H) as a model. The chemically synthesized poly-SO3H was characterized using Fourier Transform Infra-Red (FTIR) and Ultraviolet-Visible (UV-Vis) spectroscopies. The molecular weight (Mw) and elemental analysis of homopolymer poly-SO3H were also examined. We found that poly-SO3H was bactericidal against stationary phase cells of P. aeruginosa and S. aureus at a concentration of 20 mgml(-1). Surprisingly, we discovered that the same concentration (20 mgml(-1)) of poly-SO3H significantly disrupted and killed bacterial cells present in pre-established forty-eight hour static biofilms of these organisms, as shown by crystal violet and bacterial live/dead fluorescence staining assays. In support of these data, poly-SO3H extensively diminished the expression of bacterial genes related to biofilm formation in stationary phase cells of P. aeruginosa, and seemed to greatly reduce the amount of the quorum sensing molecule N-(3-oxododecanoyl)-l-homoserine lactone (3OC12-HSL) able to be recovered from biofilms of this organism. Furthermore, we found that poly-SO3H was able to effectively penetrate and kill cells in biofilms formed by the P. aeruginosa (AESIII) isolate derived from the sputum of a cystic fibrosis patient. Taken together, the results of the present study emphasise the broad antimicrobial activities of fPANI, and suggest that they could be developed further and used in some novel ways to construct medical devices and/or industrial equipment that are refractory to colonization by biofilm-forming bacteria.

  19. Action of disinfectant quaternary ammonium compounds against Staphylococcus aureus.

    PubMed

    Ioannou, Christopher J; Hanlon, Geoff W; Denyer, Stephen P

    2007-01-01

    Mode-of-action studies concluded that alkyldimethylbenzylammonium chloride (ADBAC) (a blend of C(12), C(14) and C(16) alkyl homologues) and didecyldimethylammonium chloride (DDAC) are both membrane-active agents, possessing subtly different modes of action reflecting early cell interactions against Staphylococcus aureus. ADBAC and DDAC exhibited similar MIC behaviors from 0.4 ppm to 1.8 ppm over an inoculum range of 1 x 10(5) to 1 x 10(9) CFU/ml at 35 degrees C. For ADBAC and DDAC, an increased rapidity of killing against S. aureus (final concentration, 2 x 10(9) CFU/ml) was observed at 35 degrees C compared to 25 degrees C. Concentration exponents (eta) for killing were <2.5 for both agents, and temperature influenced the eta value. Examination of leakage and kill data suggested that a single leakage marker was not indicative of cell death. ADBAC and DDAC possessed Langmuir (L4) and high-affinity (H3/4) uptake isotherms, respectively. ADBAC molecules formed a single monolayer of coverage of cells at the end of primary uptake, and DDAC formed a double monolayer. Rapid cell leakage occurred at bactericidal concentrations, with total depletion of the intracellular potassium and 260-nm-absorbing pools released in this strict order. Autolysis was observed for ADBAC and DDAC at concentrations of 9 mug/ml (0.0278 mM and 0.0276 mM, respectively) and above, together with the depletion of approximately 30% of the internal potassium pool. Autolysis contributed to ADBAC and DDAC lethality, although high biocide concentrations may have inhibited autolytic enzyme activity.

  20. Characterization of Staphylococcus aureus SarA binding sites.

    PubMed

    Sterba, Kristen M; Mackintosh, Samuel G; Blevins, Jon S; Hurlburt, Barry K; Smeltzer, Mark S

    2003-08-01

    The staphylococcal accessory regulator locus (sarA) encodes a DNA-binding protein (SarA) that modulates expression of over 100 genes. Whether this occurs via a direct interaction between SarA and cis elements associated with its target genes is unclear, partly because the definitive characteristics of a SarA binding site have not been identified. In this work, electrophoretic mobility shift assays (EMSAs) were used to identify a SarA binding site(s) upstream of the SarA-regulated gene cna. The results suggest the existence of multiple high-affinity binding sites within the cna promoter region. Using a SELEX (systematic evolution of ligands by exponential enrichment) procedure and purified, recombinant SarA, we also selected DNA targets that contain a high-affinity SarA binding site from a random pool of DNA fragments. These fragments were subsequently cloned and sequenced. Randomly chosen clones were also examined by EMSA. These DNA fragments bound SarA with affinities comparable to those of recognized SarA-regulated genes, including cna, fnbA, and sspA. The composition of SarA-selected DNAs was AT rich, which is consistent with the nucleotide composition of the Staphylococcus aureus genome. Alignment of selected DNAs revealed a 7-bp consensus (ATTTTAT) that was present with no more than one mismatch in 46 of 56 sequenced clones. By using the same criteria, consensus binding sites were also identified upstream of the S. aureus genes spa, fnbA, sspA, agr, hla, and cna. With the exception of cna, which has not been previously examined, this 7-bp motif was within the putative SarA binding site previously associated with each gene.

  1. Phosphatidylglycerol homeostasis in glycerol-phosphate auxotrophs of Staphylococcus aureus

    PubMed Central

    2013-01-01

    Background The balanced synthesis of membrane phospholipids, fatty acids and cell wall constituents is a vital facet of bacterial physiology, but there is little known about the biochemical control points that coordinate these activities in Gram-positive bacteria. In Escherichia coli, the glycerol-phosphate acyltransferase (PlsB) plays a key role in coordinating fatty acid and phospholipid synthesis, but pathogens like Staphylococcus aureus have a different acyltransferase (PlsY), and the headgroup of the major membrane phospholipid, phosphatidylglycerol (PtdGro), is used as a precursor for lipoteichoic acid synthesis. Results The PlsY acyltransferase in S. aureus was switched off by depriving strain PDJ28 (ΔgpsA) of the required glycerol supplement. Removal of glycerol from the growth medium led to the rapid cessation of phospholipid synthesis. However, the continued utilization of the headgroup caused a reduction in PtdGro coupled with the accumulation of CDP-diacylglycerol and phosphatidic acid. PtdGro was further decreased by its stimulated conversion to cardiolipin. Although acyl-acyl carrier protein (ACP) and malonyl-CoA accumulated, fatty acid synthesis continued at a reduced level leading to the intracellular accumulation of unusually long-chain free fatty acids. Conclusions The cessation of new phospholipid synthesis led to an imbalance in membrane compositional homeostasis. PtdGro biosynthesis was not coupled to headgroup turnover leading to the accumulation of pathway intermediates. The synthesis of cardiolipin significantly increased revealing a stress response to liberate glycerol-phosphate for PtdGro synthesis. Acyl-ACP accumulation correlated with a decrease in fatty acid synthesis; however, the coupling was not tight leading to the accumulation of intracellular fatty acids. PMID:24238430

  2. Auranofin efficacy against MDR Streptococcus pneumoniae and Staphylococcus aureus infections.

    PubMed

    Aguinagalde, Leire; Díez-Martínez, Roberto; Yuste, Jose; Royo, Inmaculada; Gil, Carmen; Lasa, Íñigo; Martín-Fontecha, Mar; Marín-Ramos, Nagore Isabel; Ardanuy, Carmen; Liñares, Josefina; García, Pedro; García, Ernesto; Sánchez-Puelles, José M

    2015-09-01

    Auranofin is an FDA-approved, gold-containing compound in clinical use for the oral treatment of rheumatoid arthritis and has been recently granted by the regulatory authorities due to its antiprotozoal properties. A reprofiling strategy was performed with a Streptococcus pneumoniae phenotypic screen and a proprietary library of compounds, consisting of both FDA-approved and unapproved bioactive compounds. Two different multiresistant S. pneumoniae strains were employed in a sepsis mouse model of infection. In addition, an MRSA strain was tested using both the thigh model and a mesh-associated biofilm infection in mice. The repurposing approach showed the high potency of auranofin against multiresistant clinical isolates of S. pneumoniae and Staphylococcus aureus in vitro and in vivo. Efficacy in the S. pneumoniae sepsis model was obtained using auranofin by the oral route in the dose ranges used for the treatment of rheumatoid arthritis. Thioglucose replacement by alkyl chains showed that this moiety was not essential for the antibacterial activity and led to the discovery of a new gold derivative (MH05) with remarkable activity in vitro and in vivo. Auranofin and the new gold derivative MH05 showed encouraging in vivo activity against multiresistant clinical isolates of S. pneumoniae and S. aureus. The clinical management of auranofin, alone or in combination with other antibiotics, deserves further exploration before use in patients presenting therapeutic failure caused by infections with multiresistant Gram-positive pathogens. Decades of clinical use mean that this compound is safe to use and may accelerate its evaluation in humans. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. PLASMA COAGULATION BY ORGANISMS OTHER THAN STAPHYLOCOCCUS AUREUS.

    PubMed

    BAYLISS, B G; HALL, E R

    1965-01-01

    Bayliss, Berenice G. (Washington State University, Pullman), and Elizabeth R. Hall. Plasma coagulation by organisms other than Staphylococcus aureus. J. Bacteriol. 89:101-105. 1965.-Approximately 200 organisms were investigated for their ability to clot human and rabbit plasma. Various anticoagulants were used in preparing the plasma: acid-citrate-dextrose, ethylenediaminetetraacetate, balanced oxalate, potassium and sodium oxalates, and heparin. Twelve organisms were found which coagulated citrated plasma in less than 8 hr: four strains of Streptococcus faecalis; two strains of S. faecalis var. zymogenes; three strains of S. faecalis var. liquefaciens; and one strain each of S. pyogenes, Escherichia coli, and Serratia marcescens. Six strains of coagulase-positive Staphylococcus were selected for use as controls. Experiments were performed to determine the mechanism by which these microorganisms coagulated citrated plasma. As this was the only plasma clotted, it was presumed that the citrate was utilized by the microorganisms, thereby releasing the calcium which was then made available so that normal physiological clotting could occur. To test this hypothesis, a chromatographic method was employed to determine the presence or absence of citrate. Coagulation tests, by use of increasing amounts of citrate, showed a linear relationship between the amount of citrate in the plasma and the coagulation time. It was demonstrated that the organisms mu